Download pdf - University Of Nigeria Nsukka

PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
ASOGWA CHUKWUMA JACOB
PG/M.SC/10/54624
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS
THEATRES
DEPARTMENT OF ARCHITECTURE
FACULTY OF ENVIRONMENTAL STUDIES
Digitally Signed by: Content manager’s Name
DN : CN = Webmaster’s name
Chukwuma Ugwuoke
O= University of Nigeria, Nsukka
OU = Innovation Centre
1
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
PERFORMING ARTS THEATRE ENUGU
A STUDY OF ACOUSTICS IN ARTS THEATRES
M.Sc (ARCH) THESIS REPORT
BY
ASOGWA CHUKWUMA JACOB
PG/M.Sc/10/54624
SUBMITTED TO THE DEPARTMENT OF ARCHITECTURE
IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR
THE AWARD OF THE DEGREE OF MASTER OF SCIENCE OF
THE DEPARTMENT OF ARCHITECTURE,
FACULTY OF ENVIRONMENTAL STUDIES,
UNIVERSITY OF NIGERIA,
ENUGU CAMPUS.
2
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
MARCH, 2013.
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
CHAPTER ONE
INTRODUCTION
3
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
CHAPTER ONE
1.0 INTRODUCTION
Performing arts are a form of non-visual art which are concerned with a space for a live
performance experienced by an audience within a set period of time.
“Arts are the expression of human creative talent, especially in a visual form e.g. music,
poetry, painting and dance.” (Oxford advanced learners dictionary).
Performing arts dates back as long as the Renaissance period and it cannot be separated from the
culture of a people, in which case, classified as either material culture (food, pottery, sculpture,
textile, dressing etc) or non material culture (dance, dramatic arts, storytelling and written
narratives, language etc). In other words, arts are symbolic representation of the people‘s culture.
The performing arts offer the individual certain aesthetic experiences as well as a sense of
belonging to a community. Experiences such as traditional dances, and masquerade displays
generally take place on social occasions where groups come together for recreation or the
celebration of festivals, the performance of rites and ceremonies or the worship of divinities.
Traditional performances therefore take place on a variety of social settings. The performance
itself generally takes into account not only the aim of the occasion, but also the emotional needs of
the participants.
There is a boom in the performing arts functions in the Nigerian society and as such it is speedily
gaining grounds as more and more actors and actresses are made. The language of the performing
arts can be understood by every culture and nation because of its universal nature. Over the last
decade, interest has risen in the Performing arts in Nigeria as can be seen in the number of
competitions put together by different organizations. Such competitions can be seen in the likes of
Naija Sings, Maltina dance hall etc. This demand is more than just having a place to perform and
show case talents, secondary demands such as exhibitions, accommodation, recreation and
communication have arisen. The provision of all these facilities within a complex has greatly
solved the problems organizers and performers would have faced.
4
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Performing arts theatre is very important in every country; its existence gives great opportunity for
the citizenry to learn their cultural heritage and know how to preserve them so that it can be
handed down from one generation to the next.
Modern performing arts theatres provide a wide range of facilities in catering for both small and
large groups, which developed a core of performing space balanced between multipurpose halls,
audiovisual presentations and so on . In most cases, the halls may be capable of being divided or
extended. For good acoustics and unobstructed sight lines the floors of the main auditoria are
almost always raked or stepped in tiers.
As intriguing and exciting as it sounds, it is pertinent that acoustics should be taken seriously into
consideration in other to have a conducive environment for these performances to take place.
Acoustics is the science that deals with the production, control, transmission, reception, and effects
of sound (Merriam-Webster). Since the earliest civilizations, music has been an integral part of our
lives as humans. Music has been used throughout the ages as a supplementary form of
communication, a way to stimulate the mind, as well as for entertainment. Because music has
become such a vital component to our society, it should come as no surprise that humans have
been working for millions of years to create environments more conducive to musical
performance. Science has lent itself to the study of acoustics to accommodate this need for such an
environment. This has become a continuous effort because of the nature of music and the act of
listening. Sound quality is a subjective assessment. What we consider positive aspects of a sound
varies from person to person and also varies over time periods in our history. Design criteria
needed to evolve to accommodate these trends.
Aspects of architectural design have also developed to accommodate for the changing purposes for
these structures; the ancient Greeks and Romans needed a way to project the voice for
performances of the great tragedies, whereas now we are concerned with performance of popular
music and theatre. As technology and our knowledge of acoustics expand, architects and physicists
continue to modify the designs for concert halls and theatres to achieve the optimum acoustic
experience for today‘s audience.
Depending on the properties of a surface, a sound wave will experience reflection, diffraction,
diffusion, or absorption when contacting the surface. The reflection of a sound wave is simply the
5
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
sound wave ―bouncing‖ off of a surface while retaining most of the sound wave‘s original energy.
The diffraction and diffusion of a sound wave occurs when the wave bends or scatters to move
around some obstruction, again while retaining the wave‘s original energy level. When a sound
wave encounters certain surfaces, the material will actually absorb some of the energy. An
absorption coefficient is used to evaluate the amount of sound absorption of a particular material.
Table 1 below shows the absorption coefficient of some materials.
Table 1: absorption coefficients for various materials; larger coefficients indicate a more
absorbent material
By indication in the table above, the most absorbent materials are any fabric materials and the
audience member themselves. Reverberation time is another factor that affects the quality of sound
in an enclosed space such as a performing arts theatre and occurs when sound energy remains after
the energy source has stopped producing sound. The equation below shows the reverberation time
and depends on the room volume and the area of absorptive materials:
R Time = 0.016 x V/A
Where:
0.016 is a constant of proportionality
V is the Volume of the room (m3)
A is the Area of absorption (surface x coefficient of absorption m2)
6
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Sound energy that lingers for a prolonged period of time, having a great reverberation time, can be
problematic for the production of spoken words; the clarity of a sound is compromised, as the long
reverberation time blends the sounds together.
Resonance occurs in theatres as they can be thought of as a giant resonator. When sound energy
stimulates a surface of the structure with the resonant frequency (natural frequency), the sound
quality will be affected. One of the most interesting applications of this idea is in the construction
of domes as resonators to specifically distort or channel a sound.
Good acoustician in the design of a hall is helpful for all to have an understanding of the basic
concepts in arts theatre acoustic design. The acoustician maintains an arsenal of trade secrets and
insider techniques, reserved to managing sound once it‘s been launched from the loudspeaker.
This means a good performing arts theatre will have a good intelligibility rating. The set of
minimum acoustic requirements that are met by a working performing arts theatres starts with the
direct sound from the speaker being loud enough, that means it replicates conversational sound
levels. The background noise in the arts theatre space has to be fairly quiet. The hall space
acoustics should be fairly free from echoes and other types of late reflections.
1.1BACKGROUND OF THE STUDY
Since the beginning of time, communities all over the world have turned to arts or a sense of
identity and history. This brings the need for a performing arts theatre together with the acoustical
problems associated with it.
“Architectural acoustics is the process of managing how both airborne and impact sound
is transmitted – and controlled – within a building design. While virtually every material
within a room affects sound levels to one degree or another, wall partitions, ceiling
systems and floor/ceiling assemblies are the primary elements that designers use to control
sound.‖ (James.D.Janning, AIA)
Architectural acoustics has been described as something of a black art or perhaps more charitably,
an arcane science. While not purely an art, at its best it results in structures that are beautiful as
7
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
well as functional. To produce art, however, the practitioner must first master the science of the
craft before useful creativity is possible, just as a potter must learn clay or a painter his oils. Prior
to Sabine‘s work at the beginning of the 20th century there was little to go on.
Jean Louis Charles Garnier (1825-1898), designer of the Paris Opera House, expressed his
frustration at the time;
―I gave myself pains to master this bizarre science [of acoustics] but . . . nowhere did I find
a positive rule to guide me; on the contrary, nothing but contradictory statements . . . I
must explain that I have adopted no principle, that my plan has been based on no theory,
and that I leave success or failure to chance alone . . . like an acrobat who closes his eyes
and clings to the ropes of an ascending balloon.‖ (Garnier, 1880).
The arts of music, drama, and public discourse have both influenced and been influenced by the
acoustics and architecture of their presentation environments. It is theorized that African music
and dance evolved a highly complex rhythmic character rather than the melodic line of early
European music due, in part, to its being performed outdoors.
Good architecture design in the world of today is not a luxury; but rather a necessity. Therefore,
there is a power play involved in solving acoustical problems in performing arts theatres. Each
built environment offers its own unique set of acoustical parameters. The acoustical design for a
conference room, for instance, differs greatly from the design needed for that of an arts theatre.
Understanding these differences and knowing how to utilize building materials, system design and
technologies are key factors behind successful acoustical design. This material will provide basic
background on the science and measurement of sound, as well as study on the design of
conference centre and its acoustical problem that faces conference centre.
Sound moves through building spaces in a variety of ways. Most commonly, it is transmitted
through air. But wall partitions, ceilings and floor/ceiling assemblies can also transmit both
airborne sound, such as human voices and impact sound, such as footsteps on a floor. Sounds are
measured in decibels and they travel through physical objects faster with less loss of energy than
through air. Considering two distinct surfaces, concave and convex, it is observed that the former
tend to concentrate or focus reflected sound in one area while the latter tends to disperse the sound
in multiple directions.
8
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Sound reverberation is the persistence of sound reflection after the source of the sound has ceased.
Reverberation can have both a positive and negative effect in architectural design. For example,
specifying highly reflective ceiling panels directly above the stage area in an auditorium will help
direct sound toward specific seating areas, thus enhancing the room‘s acoustical performance.
However, that same reflective performance will become a negative factor if highly reflective wall
and ceiling materials are installed in the rear of the auditorium. That‘s because the sound
reflections from the rear of the room take too long to reach the audience, resulting in a distracting
echo effect.
Therefore, good auditoria in arts theatres are designed to eliminate unwanted reflections and
echoes and to optimize the quality of the sound heard by the audience. This is done by engineering
the shape of the auditorium and the walls, as well as to including sound absorbing materials in
areas that may cause echoes. Acoustics also deals with the control of sound. "Lindsay's Wheel of
Acoustics", shown below in figure 1, describes the scope of acoustics starting from the four broad
fields of Earth Sciences, Engineering, Life Sciences, and the Arts.
9
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig. 1 Lindsay‟s wheel of acoustics.
1.2 STATEMENT OF ARCHITECTURAL PROBLEMS
The architectural problem is identifying the key areas in the building that are susceptible to sound.
For the purposes of this research, the major areas of concentration which the author intends to
solve are the floor, ceiling and walls of the auditorium for effective sound control and
management. This can be achieved through architectural designs with the use of proper form and
shape for the auditoria, adoption and application of good absorbent materials and seating
arrangements with raked floors.
10
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
1.3 AIM OF THE STUDY
The aim of this research work is to provide a tranquil and comfortable environment conducive
enough for performance in arts theatre through determination of ways to improve sound quality.
1.4 OBJECTIVES OF THE STUDY
The specific objectives of this study are:
a. Planning of acoustics at the inception of design through environmental analysis of the proposed
site.
b. Application of passive and appropriate active noise defend mechanisms in design
c. Appraisals of similar existing projects (post evaluation).
1.5 SIGNIFICANCE OF THE STUDY
Due to the growing need for preservation and conservation of culture, performing spaces are
necessary for cultural heritage. This research work will deal with evolving architecture devoid of
real time acoustic problems and also a breaking ground for a structure unique and native to the
Igbo race.
1.6 SCOPE OF THE STUDY
The project would be limited to designing modern structure to the scale of state level for holding
performances in arts like dramas, dancing, music etc which would provide the force for
accommodating a good number of individual.
11
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
1.7RESEARCH METHOLOGY
Primary data
For the purpose of this study, the qualitative method of research shall be adopted backed with case
studies and used as the instrument for collection of primary data.
Primary data includes:

Direct interviews and enquiries from people.

Author‘s fore-knowledge on related noted matters on the current study

Carrying out site visits and studies; investigations and direct observation on the proposed project
site by the author.

Retrieving information beneficial to the current study from author‘s personal diaries e.t.c.

Taking photographs of such visited existing facilities and producing diagrams for illustrative
purposes of such.
Secondary Data Collection
Secondary sources of information shall be from already collected data by other researchers
through books, journals, published and unpublished literature, articles, and text books related to
the area of study and also the massive electronic data bank referred to as the ‗internet‘. It can be
used to get a new perspective on the current study, to supplement or compare the work or to use
parts of it as long as the data remain relevant. The data collected will be reviewed and used as
bases for concept generation and analysis.
12
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
REFERENCES
Garnier .C. (1880), Le nouveau Opéra de Paris, 2 vols. Ducher et Cie, Paris
Oxford advanced learners dictionary
Wilson, C.E. (1989), Noise Control, Harper & Row Publishers, New York.
W.J. Cavanaugh and J.A. Wilkes (1999), Architectural Acoustics, John Wiley & Sons, New York.
Evans, Jack B.(1999), “Acoustical Noise Control Recommendations for Building Mechanical
Systems 904”, JEAcoustics.
C. Himmel and J. Evans (2002), “Texas Heart Institute Acoustical Performance Testing Results”,
JEAcoustics.
13
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
CHAPTER TWO
LITERATURE REVIEW
14
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
CHAPTER TWO
2.0 LITERATURE REVIEW
2.1 HISTORY OF ACOUSTICS AND THEATRES
Greek and Roman period
The origin of music, beginning with some primeval song around an ancient campfire, is
impossible to date. The understanding of music and consonance dates back at least to 3000 BC,
when the Chinese philosopher Fohi wrote two monographs on the subject (Skudrzyk, 1954). As
the need arose to address large groups for entertainment, military, or political purposes, it became
apparent that concentric circles brought the greatest number of people close to the central area.
Since the human voice is directional and intelligibility decreases as the listener moves off axis,
seating arrangements were defined by the vocal polar pattern and developed naturally, as people
sought locations yielding the best audibility.
This led to the construction of earthen or stone steps, arranging the audience into a semicircle in
front of the speaker. The need to improve circulation and permanence evolved in time to the
construction of dedicated amphitheaters on hillsides based on the same vocal patterns. The Greeks,
perhaps due to their democratic form of government, built some of the earliest outdoor
amphitheaters. The seating plan was in the shape of a segment of a circle, slightly more than 180◦,
often on the side of a hill facing the sea. One of the best-preserved examples of the GrecoHellenistic theatre is that built at Epidaurus in the northeastern Peloponnese in 330 BC, about the
time of Aristotle. A sketch of the plan is shown in Fig. 2.0. The seating was steeply sloped in these
structures, typically 2:1, which afforded good sight lines and reduced grazing attenuation. Even
with these techniques, it is remarkable that this theater, which seated as many as 17,000 people,
actually functioned.
15
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Figure 2.0 Ancient Theater at Epidaurus, Greece (Izenour, 1977)
The Roman and the late Hellenistic amphitheaters followed the earlier Greek seating pattern, but
limited the seating arc to 180◦. They also added a stage house (skene) behind the actors, a raised
acting area (proskenion), and hung awnings (valeria) overhead to shade the patrons. The chorus
spoke from a hard-surfaced circle (orchestra) at the center of the audience. A rendering of the
Roman Theatre at Aspendius, Turkey is shown in Fig. 2.1. The Romans were better engineers than
the early Greeks and, due to their development of the arch and the vault, were not limited to
building these structures on the natural hillsides.
16
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig. 2.1 Roman Theater at Aspendus, Turkey (Izenour, 1977)
The Odeon of Agrippa, a structure built in Athens in Roman times (12 BC), was a remarkable
building. Shown in Fig. 2.2, it had a wood-trussed clear span of over 25 meters (83 feet). It finally
collapsed in the middle of the second century. Izenour (1977) points out that these structures,
which ranged in size from 200 to 1500 seats, are found in many of the ancient Greek cities. He
speculates that, ―during the decline of the Empire these roofed theaters, like the small
noncommercial theaters of our time, became the final bastion of the performing arts, where the
more subtle and refined stage pieces—classical tragedy and comedy, ode and epoch—were
17
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
performed, the latter to the accompaniment of music (lyre, harp, double flute and oboe) hence the
name odeum, ‗place of the ode‘.‖
Figure 2.2 Odeon of Agrippa at Athens, Greece (Izenour, 1977)
Much of our knowledge of Roman architecture comes from the writings of Vitruvius Pollio, a
working architect of the time, who authored De Architectura. Dating from around 27 BC, this
book describes his views on many aspects of architecture, including theater design and acoustics.
Some of his ideas were quite practical—such as his admonition to locate theaters on a ―healthy‖
site with adequate ventilation (away from swamps and marshes). Seating should not face south,
causing the audience to look into the sun. Unrestricted sightlines were considered particularly
important, and he recommended that the edge of each row should fall on a straight line from the
first to the last seat. His purpose was to assure good speech intelligibility as well as good
sightlines.
18
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Vitruvius also added one of the great historical mysteries to the acoustical literature. He wrote that
theaters should have large overturned amphora or sounding vases placed at regular intervals
around the space to improve the acoustics. These were to be centered in cavities on small, 150mm
(6‖) high wedges so that the open mouth of the vase was exposed to the stage, as shown in a
conjectural restoration by Izenour in Fig. 2.3, based on an excavation of a Roman theater at Beth
Shean in Israel. The purpose, and indeed the existence of these vases, remains unclear. Even
Vitruvius could not cite an example of their use, though he assures us that they existed in the
provinces.
Fig 2.3 Hypothetical Sounding Vases (Izenour,
1977). A conjectural restoration in section of sounding vases in a cavity found at a roman theatre
at Beth she an, Israel
Renaissance Theaters
Theater construction began again in Italy in the early Renaissance, more or less where the Romans
had left it a thousand years earlier. In 1580, the Olympic Academy in Vicenza engaged Palladio
(1518–1580) to build a permanent theater (Fig. 2.4), the first since the Roman Odeons. The seating
plan was semi-elliptical, following the classical pattern, and the stage had much the same
orchestra and proskenium configuration that the old Roman theaters had. Around the back of the
audience was a portico of columns with statues
19
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig 2.4 Teatro Olimpico, Vicenza, Italy (Breton, 1989)
above. The newly discovered art of perspective captured the imagination of designers and they
crafted stages, which incorporated a rising stage floor and single point perspective. The terms
upstage and downstage evolved from this early design practice. After the death of Palladio, his
pupil Scamozzi added five painted streets in forced perspective angling back from the scaena.
In 1588, Scamozzi further modified the Roman plan in a new theater, the Sabbioneta. The semielliptical seating plan was pushed back into a U shape, the stage wall was removed, and a singlepoint perspective backdrop replaced the earlier multiple-point perspectives. This theater is
illustrated in Fig. 2.5. Its seating capacity was small and there was little acoustical support from
reflections off the beamed ceiling.
In mid-sixteenth century England, traveling companies of players would lay out boards to cover
the muddy courtyards of inns, while the audience would stand around them or line the galleries
that flanked the main yard (Breton, 1989). Following the first permanent theater built in 1576 by
James Burbage, this style became the model for many public theaters, including Shakespeare‘s
Globe. The galleries surrounding the central court were three tiers high with a roofed stage, which
looked like a thatched apron at one end. Performances were held during the day without a curtain
or painted backdrop. The acoustics of these early theaters was probably adequate. The side walls
provided beneficial early reflections and the galleries yielded excellent sightlines. The open-air
20
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig 2.5 Sabbioneta Theater, Italy (Breton, 1989)
courtyard reduced reverberation problems and outside noise was shielded by the high walls. It is
remarkable that such simple structures sufficed for the work of a genius like Shakespeare. Without
good speech intelligibility provided by this type of construction, the complex dialogue in his plays
would not only have been lost on the audience, it would probably not have been attempted at all.
Baroque Theaters
The progress in theater construction in Northern Italy was also quite rapid. The illusion stages
gave way to auditoria with horizontally sliding flats, and subsequently to moveable stage
machinery. The Theatro Farnese in Parma, constructed between 1618 and 1628 by Giovanni
Battista Aleotti, had many features of a modern theater. Shown in Fig. 2.6, it featured horizontal
set pieces, which required protruding side walls on either side of the stage opening to conceal
them. This allowed set changes to be made and provided entrance spaces on the side wings for the
actors to use without appearing out of scale. The U-shaped seating arrangement afforded the
patrons a view, not only of the stage, but also of the prince, whose box was located on the
centerline.
21
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
In Florence at the Medici court, operas were beginning to be written. The first one was Dafne,
which is now lost, written between 1594 and 1598 by Peri (Forsyth, 1985). The first known opera
performance was Peri‘s Euridice, staged at a large theater in the Pitti Palace to celebrate the
wedding of Maria de‘Medici and King Henri IV of France in 1600. This was followed by
Monteverdi‘s Orfeo, first performed in 1607 in Mantua, which transformed opera from a
somewhat dry and academic style to a vigorous lyric drama.
Fig 2.6 Theatro Farnese, Parma, Italy (Breton, 1989)
Classical Theatres
The eighteenth century in Europe was a cosmopolitan time when enlightened despots (often
foreign born) were on the throne in many countries, and an intellectual movement known as the
Enlightenment held that knowledge should evolve from careful observation and reason. The
French philsophes, Rousseau, Montesquieu, and Voltaire reacted to the social conditions they saw
and sought to establish universal rights of man. In both the visual and performing arts, there was a
22
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
classic revival, a return to the spirit of ancient Greece and Rome. During the Classical period
musical pieces were composed for the first time with a formal concert hall performance in mind.
Previously rooms that were used for musical concerts were rarely built specifically for that sole
purpose.
In continental Europe in the mid eighteenth century there was not yet a tradition of public concerts
open to all. Concert-goers were, by and large, people of fashion and concerts were usually held in
rooms of the nobility, such as Eisenstadt Castle south of Vienna or Eszterhaza Castle in Budapest,
which was the home of Haydn during his most productive years. It was not until 1761 that a public
hall was built in Germany, the Konzert-Saal auf dem Kamp in Hamberg. In Leipzig, perhaps
because it did not have a royal court, the architect Johann Carl Friedrich Dauthe converted a
Drapers‘ Hall into a concert hall in 1781. Later known as the Altes Gewandhaus, it seated about
400 with the orchestra located on a raised platform at one end occupying about one quarter of the
floor space (Fig. 2.7). The room had a reverberation time of about 1.3 seconds and was lined with
wood paneling, which reduced the bass build up. Recognized for its fine acoustics, particularly
during Felix Mendelssohn‘s directorship in the mid-nineteenth century (1835–1847), it was later
replaced by the larger Neus Gewandhaus late in the century.
Figure 2.7 Altes Gewandhaus, Leipzig, Germany (Bagenal and Wood, 1931)
23
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Meanwhile in Italy little had changed. Opera was the center of the cultural world and opera-house
design had developed slowly over two centuries. In 1778 La Scalla opened in Milan and has
endured, virtually unchanged, for another two centuries. Shown in Fig. 2.8, it has the form of a
horseshoe-shaped layer cake with small boxes lining the walls. The sides of the boxes are only
about 40% absorptive so they provide a substantial return of reflected sound back to the room and
to the performers. The orchestra seating area is nearly flat, reminiscent of the time when there
were no permanent chairs there. The seating arrangement is quite efficient (tight by modern
standards), and the relatively low (1.2 sec) reverberation time makes for good intelligibility.
Fig 2.8 Theatro Alla Scalla, Milan, Italy (Beranel, 1979)
24
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Knowledge of the acoustical behavior of rooms had not yet been set out in quantitative form.
Successful halls were designed using incremental changes from previously constructed rooms. The
frustration of many nineteenth-century architects with acoustics is summarized in the words of
Jean Louis Charles Garnier, designer of the Paris Opera House,
“I gave myself pains to master this bizarre science [of acoustics] but . . . nowhere did I
find a positive rule to guide me; on the contrary, nothing but contradictory statements . . . I
must explain that I have adopted no principle, that my plan has been based on no theory,
and that I leave success or failure to chance alone . . . like an acrobat who closes his eyes
and clings to the ropes of an ascending balloon.‖ (Garnier, 1880)
One of the more interesting theatrical structures to be built in the century, Wagner‘s opera house,
the Festspielhaus in Bayreuth, Germany built in 1876, was a close collaboration between the
composer and the architect, Otto Brueckwald, and was designed with a clear intent to accomplish
certain acoustical and social goals. The auditorium is rectangular but it contains a fan-shaped
seating area with the difference being taken up by a series of double columns supported on wing
walls. The plan and section are shown in Fig. 2.9. The seating arrangement in itself was an
innovation, since it was the first opera house where there was not a differentiation by class
between the boxes and the orchestra seating. The horseshoe shape with layered boxes, which had
been the traditional form of Italian opera houses for three centuries, was abandoned for a more
egalitarian configuration. Most unusual, however, was the configuration of the pit, which was
deepened and partially covered with a radiuses shield that directed some of the orchestral sound
back toward the actors. This device muted the orchestral sound heard by the audience, while
allowing the musicians to play at full volume out of sight of the audience. It also changed the
loudness of the strings with respect to the horns, improving the balance between the singers and
the orchestra. The reverberation time, at 1.55 seconds (Beranek, 1996), was particularly well
suited to Wagner‘s music, perhaps because he composed pieces to be played here, but the style has
not been replicated elsewhere.
25
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Figure 2.9 Festspielhaus, Bayreuth, Germany (Beranek, 1979)
Italian Opera Houses
By 1637, when the first public opera house was built in Venice (Fig. 2.10), the operatic theater had
become the multistory U-shaped seating arrangement of the Theatro Farnese, with boxes in place
of tiers. Later the seating layout further evolved from a U shape into a truncated elliptical shape.
The orchestra, which had first been located at the rear of the stage and then in the side balconies,
was finally housed beneath the stage as is the practice today.
26
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig 2.10 Theater of SS. Giovanni e Paolo, Venice, Italy (Forsyth, 1985)
Horse Shoe halls
Several of the orchestral halls constructed in the late eighteenth and early nineteenth centuries are
among the finest ever built. Four of them are particularly noteworthy, both for their fine acoustics
and for their influence on later buildings. They are all of the shoebox type with high ceilings,
multiple diffusing surfaces, and a relatively low seating capacity. The oldest is the Stadt Casino in
Basel, Switzerland, which was completed in 1776. Shown in Fig. 2.11 it is very typical of the age
with a flat floor reminiscent of the earlier ballrooms, small side and end balconies, and a coffered
ceiling. The orchestra was seated on a raised platform with risers extending across its width.
Above and to the rear of the orchestra was a large organ. The hall seated 1448 people and had a
mid-frequency reverberation time of about 1.8 seconds making it ideal for Classical and Romantic
music.
27
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Figure 2.11 Concert Hall, Stadt Casino, Basel, Switzerland (Beranek, 1979)
2.2ORIGIN OF SOUND THEORY
The understanding of the theory of fluids including sound propagation through them made little
progress from the Greeks to the Renaissance. Roman engineers did not have a strong theoretical
basis for their work in hydraulics (Guillen, 1995). They knew that water flowed downhill and
would rise to seek its own level. This knowledge, along with their extraordinary skills in structural
engineering, was sufficient for them to construct the massive aqueduct systems including
rudimentary siphons. However, due to the difficulty they had in building air-tight pipes it was
more effective for them to bridge across valleys than to try to siphon water up from the valley
floors. Not until Leonardo da Vinci (1452–1519) studied the motion and behavior of rivers did he
notice that, ―A river of uniform depth will have more rapid flow at the narrower section than at the
28
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
wider.‖ This is what we now call the equation of continuity, one of the relationships necessary for
the derivation of the wave equation.
Galileo Galilei along with others noted the isochronism of the pendulum and was aware, as was
the French Franciscan friar Marin Mersenne, of the relationship between the frequency of a
stretched string and its length, tension, and density. Earlier Giovanni Battista Benedetti had related
the ratio of pitches to the ratio of the frequencies of vibrating objects. In England Robert Hooke,
who had bullied a young Isaac Newton on his theory of ligh (Guillen, 1995), published in 1675
the law of elasticity that now bears his name, in the form of a Latin anagram CEIIINOSSSTTUV,
which decoded is ―ut tensio sic vis‖ (Lindsay, 1966). It established the direct relationship between
stress and strain that is the basis for the formulas of linear acoustics. The first serious attempt to
formalize a mathematical theory of sound propagation was set forth by Newton in his second book
(1687), Philosophiae Naturalis Principia Mathematica. In this work he hypothesized that the
velocity of sound is proportional to the square root of the absolute pressure divided by the density.
Newton had discovered the isothermal velocity of sound in air. This is a less generally applicable
formula than the adiabatic relationship, which was later suggested by Pierre Simon Laplace in
1816. A fuller understanding of the propagation of sound waves had to wait until more elaborate
mathematical techniques were developed.
Daniel Bernoulli (1700–1782), best known for his work in fluids, set forth the principle of the
coexistence of small amplitude oscillations in a string, a theory later known as superposition. Soon
after, Leonhard Euler (1707–1783) published a partial differential equation for the vibration modes
in a stretched string. The stretched-string problem is one that all physics studies, due both to its
relative simplicity and its importance in the history of science. The eighteenth century was a time
when mathematics was just beginning to be applied to the study of mechanics. Prizes were offered
by governments for the solution of important scientific problems of the day and there was vigorous
and frequently acrimonious debate among natural philosophers in both private and public
correspondence on the most appropriate solutions.
The behavior of sound in pipes and tubes was also of interest to mathematicians of the time. Both
Euler (1727) and later J. L. Lagrange (1736–1830) made studies of the subject. Around 1759 there
was much activity and correspondence between the two of them. (Lindsay, 1966). In 1766, Euler
29
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
published a detailed treatise on fluid mechanics, which included a section entirely devoted to
sound waves in tubes. The tradition of offering prizes for scientific discoveries continued into the
nineteenth century. The Emperor Napoleon offered, through the Institute of France, a prize of
3000 francs for a satisfactory theory of the vibration of plates (Lindsay, 1966). The prize was
awarded in 1815 to Sophie Germain, a celebrated woman mathematician, who derived the correct
fourth-order differential equation. The works of these early pioneers, along with his own insights,
ultimately were collected into the monumental two-volume work, Theory of Sound, by John W.
Strutt, Lord Rayleigh (1842–1919) in 1877. This classic work contains much that is original and
insightful even today.
In the 6th century BC, the ancient Greek philosopher Pythagoras wanted to know why
some musical intervals seemed more beautiful than others, and he found answers in terms of
numerical ratios representing the harmonic overtone series on a string. He is reputed to have
observed that when the lengths of vibrating strings are expressible as ratios of integers (e.g. 2 to 3,
3 to 4), the tones produced will be harmonious. If, for example, a string sounds the note C when
plucked, a string twice as long will sound the same note an octave lower. The tones in between are
then given by 16:9 for D, 8:5 for E, 3:2 for F, 4:3 for G, 6:5 for A, and 16:15 for B, in ascending
order. Aristotle (384-322 BC) understood that sound consisted of contractions and expansions of
the air "falling upon and striking the air which is next to it...", a very good expression of the nature
of wave motion. In about 20 BC, the Roman architect and engineer Vitruvius wrote a treatise on
the acoustic properties of theatres including discussion of interference, echoes, and
reverberation—the beginnings of architectural acoustics (see figure 2.12).
30
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig.2.12 the fundamental and the first 6 overtones of a vibrating string.
2.3BEGINNING OF MODERN ACOUSTICS
The nineteenth century produced the beginnings of the study of acoustics as a science and its
dissemination in the published literature via technical books and journals. Heretofore scientific
ideas had a relatively limited audience and were often distributed through personal correspondence
between leading scholars of the day. Frequently written in Latin they were not generally accessible
to the public. In the nineteenth century, books written in English or German, such as Hermann von
Helmholtz (1821–1894) Sensations of Tone in 1860, established the field as a science where
measurement, observation, and a mathematical approach could lead to significant progress. Later
in the century (1877) John W. Strutt, Lord Rayleigh published the first of his two-volume set,
Theory of Sound, followed by the second between 1894 and 1896, which was one of the most
important books ever written in the field. In it he pulled together the disparate technical articles of
the day and added many valuable contributions of his own. It is remarkable that such a clear
presentation of acoustical phenomena was written before careful experimental work was possible.
In Rayleigh‘s time the only practical sound source was a bird whistle (Lindsay, 1966) and the most
sensitive detection device (besides the ear) was a gas flame.
In the late nineteenth and early twentieth centuries, the theoretical beginnings of architectural
acoustics were started by a young physics professor at Harvard College, W. C. Sabine. Sabine‘s
work began inauspiciously enough following a request by President Elliot to ―do something‖ about
the acoustical difficulties in the then new Fogg Art Museum auditorium, which had been
31
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
completed in 1895 (Sabine, 1922). Sabine took a rather broad view of the scope of this mandate
and commenced a series of experiments in three Harvard auditoria with the goal of discovering the
reasons behind the difficulties in understanding speech. By the time he had completed his work, he
had developed the first theory of sound absorption of materials, its relationship to sound decay in
rooms, and a formula for the decay (reverberation) time in rooms. His key discovery was that the
product of the total absorption and the reverberation time was a constant.
Soon after this discovery in 1898 he helped with the planning of the Boston Music Hall, now
called Symphony Hall. He followed the earlier European examples, using a shoebox shape and
heavy plaster construction with a modest ceiling height to maintain a reverberation time of 1.8
seconds. Narrow side and rear balconies were used to avoid shadow zones and a shallow stage
enclosure, with angled walls and ceiling, directed the orchestra sound out to the audience. The
deeply coffered ceiling and wall niches containing classical statuary helped provide excellent
diffusion (Hunt, 1964). The auditorium, pictured in Fig. 2.13, opened in 1900 and is still one of the
three or four best concert halls in the world.
Despite its size it has reasonably good acoustics in the middle balconies; however, the orchestra
seats and the upper balcony seats are less satisfactory (Beranek, 1979). With a volume nearly
twice that of La Scalla, it is difficult for singers to sound as loud as in Milan. The hall, with some
ceiling and balcony front additions, has increased diffusion and the sound in the balconies, is in
active use today.
32
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Figure 2.13 Symphony Hall, Boston, MA, USA (Beranek, 1979)
2.4FUNDAMENTALS OF ACOUSTICS
Frequency and wavelength
A steady sound is produced by the repeated back and forth movement of an object at regular
intervals. The time interval over which the motion recurs is called the period. For example if our
hearts beat 72 times per minute, the period is the total time (60 seconds) divided by the number of
beats (72), which is 0.83 seconds per beat. We can invert the period to obtain the number of
complete cycles of motion in one time interval, which is called the frequency.
33
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
f = 1/T
where f = frequency (cycles per second or Hz)
T = time period per cycle (s)
The frequency is expressed in units of cycles per second, or Hertz (Hz), in honor of the physicist
Heinrich Hertz.
Among the earliest sources of musical sounds were instruments made using stretched strings.
When a string is plucked it vibrates back and forth and the initial displacement travels in each
direction along the string at a given velocity. The time required for the displacement to travel
twice the length of the string is
T = 2 L/c
Figure 2.14 Harmonics of a Stretched String (Pierce, 1983)
Where T = time period (s)
L = length of the string (m)
c = velocity of the wave (m /s)
34
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Since the string is fixed at its end points, the only motion patterns allowed are those that have zero
amplitude at the ends. This constraint (called a boundary condition) sets the frequencies of
vibration that the string will sustain to a fundamental and integer multiples of this frequency, 2f,
3f, 4f. . . called harmonics. Figure 2.14 shows these vibration patterns.
f = c/2 L
As the string displacement reflects from the terminations, it repeats its motion every two lengths.
The distance over which the motion repeats is called the wavelength, and is given the Greek
symbol lambda, λ, which for the fundamental frequency in a string is 2 L.
This leads us to the general relation between the wavelength and the frequency
λ = c/f
Where λ = wavelength (m)
c = velocity of wave propagation (m /s)
f = frequency (Hz)
When notes are played on a piano the strings vibrate at specific frequencies, which depend on their
length, mass, and tension.
2.5 SOUND WAVES
Pressure fluctuations
A sound wave is a longitudinal pressure fluctuation that moves through an elastic medium. It is
called longitudinal because the particle motion is in the same direction as the wave propagation. If
the displacement is at right angles to the direction of propagation, as is the case with a stretched
string, the wave is called transverse. The medium can be a gas, liquid, or solid, though in our
everyday experience we most frequently hear sounds transmitted through the air. Our ears drums
are set into motion by these minute changes in pressure and they in turn help create the electrical
impulses in the brain that are interpreted as sound. The ancient conundrum of whether a tree
falling in a forest produces a sound, when no one hears it, is really only an etymological problem.
35
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
A sound is produced because there is a pressure wave, but a noise, which requires a subjective
judgment and thus a listener, is not.
Sound generation
All sound is produced by the motion of a source. When a piston, such as a loudspeaker, moves into
a volume of air, it produces a local area of density and pressure that is slightly higher than the
average density and pressure. This new condition propagates throughout the surrounding space
and can be detected by the ear or by a microphone. When the piston displacement is very small
(less than the mean free path between molecular collisions), the molecules absorb the motion
without hitting other molecules or transferring energy to them and there is no sound. Likewise if
the source moves very slowly, air flows gently around it, continuously equalizing the pressure, and
again no sound is created (Ingard, 1994). However, if the motion of the piston is large and
sufficiently rapid that there is not enough time for flow to occur, the movement forces nearby
molecules together, locally compressing the air and producing a region of higher pressure. What
creates sound is the motion of an object that is large enough and fast enough that it induces a
localized compression of the gas. Air molecules that are compressed by the piston rush away from
the high-pressure area and carry this additional momentum to the adjacent molecules. If the piston
moves back and forth a wave is propagated by small out-and-back movements of each successive
volumeelement in the direction of propagation, which transfer energy through alternations of high
pressure and low velocity with low pressure and high velocity. It is the material properties of mass
and elasticity that ensure the propagation of the wave.
Wavelength of sound
The wavelength of a sound wave is a particularly important measure. Much of the behavior of a
sound wave relates to the wavelength, so that it becomes the scale by which we judge the physical
size of objects. For example, sound will scatter (bounce) off a flat object that is several
wavelengths long in a secular (mirror-like) manner. If the object is much smaller than a
wavelength, the sound will simply flow around it as if it were not there. If we observe the behavior
of water waves we can clearly see this behavior. Ocean waves will pass by small rocks in their
path with little change, but will reflect off a long breakwater or similar barrier.
36
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Velocity of sound
The mathematical description of the changes in pressure and density induced by a sound wave,
which is called the wave equation, requires that certain assumptions be made about the medium. In
general we examine an element of volume (say a cube) small enough to smoothly represent the
local changes in pressure and density, but large enough to contain very many molecules. When we
mathematically describe physical phenomena created by a sound wave, we are talking about the
average properties associated with such a small volume element.
Table 2.1 speed of sound in various materials
The twentieth century saw a burgeoning of technological applications of the large body of
scientific knowledge that was by then in place. The first such application was Sabine‘s
groundbreaking work in architectural acoustics, and many others followed. Underwater acoustics
was used for detecting submarines in the First World War Sound recording and the telephone
played important roles in a global transformation of society. Sound measurement and analysis
37
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
reached new levels of accuracy and sophistication through the use of electronics and computing.
The ultrasonic frequency range enabled wholly new kinds of application in medicine and industry.
New kinds of transducers (generators and receivers of acoustic energy) were invented and put to
use.
Plate 2.0 Principles of acoustics were applied since ancient times: Roman theatre in the city of Amman.
2.6 CONCEPT OF ACOUSTICS
The study of acoustics revolves around the generation, propagation and reception of mechanical
waves and vibrations.
The steps shown in the above diagram can be found in any acoustical event or process. There are
many kinds of cause, both natural and volitional. There are many kinds of transduction process
that convert energy from some other form into acoustic energy, producing the acoustic wave.
There is one fundamental equation that describes acoustic wave propagation, but the phenomena
that emerge from it are varied and often complex. The wave carries energy throughout the
propagating medium. Eventually this energy is transuded again into other forms, in ways that
again may be natural and/or volitionally contrived. The final effect may be purely physical or it
38
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
may reach far into the biological or volitional domains. The five basic steps are found equally well
whether we are talking about an earthquake, a submarine using sonar to locate its foe, or a band
playing in a rock concert.
The central stage in the acoustical process is wave propagation. This falls within the domain of
physical acoustics. In fluids, sound propagates primarily as a pressure wave. In solids, mechanical
waves can take many forms including longitudinal waves, transverse waves and surface waves.
Acoustics looks first at the pressure levels and frequencies in the sound wave. Transduction
processes are also of special importance.
The Difference between Light and Sound
Because human senses are analogous in many ways, there is a mistaken tendency to think of sound
as being similar to light, giving the impression that all you need to do is ―illuminate‖ an area with
sound. Unfortunately, this analogy falls short because of the basic physics involved.
The airborne wavelengths that we perceive as sound are much longer than the electromagnetic
waves that we sense as light. When multiple light sources are beamed at the same place in a room,
the light level increases without producing detectable visual distortion. By contrast, multiple sound
waves projecting into the same place within a room can interfere adversely with each other, and
can even cancel each other out, unless the room acoustics and sound system are specifically
designed not to do so. This interference can remove important portions of the sound spectrum, can
result in different sound quality at different spots within the room, and can smear the time arrival
of the sound. All these factors can make music muddy and unappealing and can make speech
unintelligible.
Common causes of such interference include reflections and loudspeaker interaction issues.
39
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Plate 2.1 When Roswell United Methodist Church upgraded the sound system in its 2,000-seat
sanctuary, matching the sound system to acoustics resulted in uncompromised intelligibility from
the podium and crystal clear sound from the choir, organ and praise band.
Sound Reflections
Solid straight surfaces, like fronts of balconies, can create reflections. In the case of a balcony at
the rear of a theatre or auditorium, the sound reflected back into the audience makes it difficult for
those seated between the stage and balcony to understand speech because they hear both the
original sound and the echoes, which are reflected sounds that reach the ear at a later time than the
original sound coming from the stage. The result is garbled, unintelligible speech.
Room and Wall Shapes
Concave, round shapes, including parabolic walls and domed ceilings, are among the worst shapes
for a room in which speech is important. The concave shape focuses sound into specific areas,
making those areas acoustically louder than other parts of the room and producing strong late
40
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
reflections that are out of time-sync with the original sound from the stage or front loudspeaker.
This causes intelligibility problems. Dividing concave surfaces into multiple convex surfaces can
diffuse (or split) the reflected wave into a number of smaller waves going in different directions,
making each less bothersome to the audience.
Acoustical Treatment
Acoustically absorptive materials tend to be frequency-selective, meaning that some materials will
absorb only high frequency sounds while others will absorb both high frequencies and the
midrange frequencies that span human speech. It is important to ensure that the material selected
for wall coverings, window treatments, acoustical baffles, etc., absorbs the intended frequencies in
just those areas where absorption is required. Other treatments, such as using diffusers to split up
the sound wave, might be more effective at times. A qualified acoustician can advise about which
the most effective treatment for a specific problem is.
The 30-Millisecond, 30-Foot Principle
When do reflections become bothersome to the listeners? When a reflected sound‘s path length is
30 feet longer than the original sound, the reflection will hinder intelligibility. That‘s because the
human brain integrates sounds that arrive within 30 milliseconds (ms) of each other to perceive a
single sound. Reflections that arrive more that 30 ms after the original sound are perceived as
echoes, which interfere with definition of music and comprehension of speech.
Sound travels at approximately one foot per millisecond. That allows us to convert the 30 ms time
figure into a distance of 30 feet. When the total path of a reflected sound –that is, the distance the
sound travels from the listener to the reflective surface and back to the listener – is more than 30
feet, the reflection will hinder intelligibility. For example, reflections from a wall located 10 feet
behind the listener are usually OK because after the original sound passes the listener, it takes 10
ms to get to the back wall and another 10 ms for the reflection to travel back to the listener, for a
total of 20ms. However, that same wall located 20 feet behind the listener can be a real problem,
because 20 ms from the listener to the wall and another 20 ms back to the listener totals 40 ms,
which breaks the 30-ms guideline (see Fig. 2.16).
41
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig 2.16 Reflections from the back wall can be problematic, degrading speech intelligibility and
clarity of music.
Solutions could involve applying absorptive materials to the reflecting surface to reduce the
amount of reflected sound, altering the shape of the reflective surface to break up the coherence of
the reflected wave, or redesigning the sound system so that it does not excite the reflection in the
first place.
By contrast, early reflections hitting the ear within the 30 ms guideline – particularly those coming
from the sides, called early lateral reflections – can enhance the spaciousness of the sound, giving
the room a warm ambience. Some performance halls are designed with close sidewalls to improve
the sound by increasing the number and density of early lateral reflections.
Noise Control
Noise from air handling systems and adjacent spaces can also reduce the quality of sound within a
room and should therefore be examined and baffled if necessary.
2.7 PRINCIPLES OF SOUND SYSTEM
The Audio Spectrum
Audio wavelengths are measured in cycles per second, or hertz (Hz). So, for example, 440 Hz, the
frequency of the A note above middle C on a piano, equals 440 cycles per second. The audible
42
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
spectrum for humans is 20 Hz to 20 kHz (20,000 Hz). For live or recorded music, the entire
audible spectrum needs to be considered. For speech intelligibility, sound system designers need to
pay particular attention to the middle range of frequencies, generally from 500 Hz to 4 kHz.
However, even for speech-only systems, the frequencies below and above this band are important
for imparting a natural sound character to voices, and for avoiding booms or thin speech character.
Each portion of the audio spectrum imparts its own challenges due to differences in wavelengths.
High frequencies have short wavelengths. Lower frequencies have longer wavelengths.
Sound System Optimization
In addition to loudspeakers themselves, sound systems require properly designed drive electronics,
which must be adjusted using proper equipment and techniques. These systems provide specific
tonal compensation (equalization), time delay and crossover functions. However, electronic
adjustments cannot correct many types of acoustical problems, especially reflections in the form of
echoes or reverberation. Equalization should be considered the ―frosting on the cake‖ in a welldesigned room and sound system.
Delay-Fill Speakers and Distributed Sound Systems
Fill speakers allow shadowed areas, such as under balconies, to be covered with sound. The signal
to fill speakers needs to be electronically delayed so that the sound arrives at the listener‘s ears in
time-sync (i.e., within 30 ms) of the sound from the main speakers. Delay-fill speakers can also be
used part way back in the room to cover the immediate area around them. For example, in fanshaped rooms it is common to see one ring of main speakers near the stage augmented by a second
ring of delay-fill speakers part way back in the room, and perhaps a third delay-fill ring even
farther back. These can then be augmented by under-balcony delay speakers in the shadowed areas
that none of the other speakers cover.
43
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Table 2.2 Distributed sound systems consist of multiple speakers. A common type of distributed system uses
speakers projecting down from the ceiling, each covering a specific area. Distributed systems are common
in places like offices, yet are also used in ancillary areas of performance venues.
Obstructions & Line-of-Sight
Whereas the long wavelengths of low frequencies can diffract (or bend) around objects, the shorter
wavelengths of high frequencies are blocked by objects in their path, leading to portions of the
audio spectrum disappearing for listeners seated behind an obstruction.
For listeners to hear midrange and high frequencies clearly in a theatre or auditorium,
loudspeakers need to place in a straight line-of-sight position to all members of the audience.
Naturally, this means that the loudspeakers tend to be visible to the audience and thus have the
potential to interfere with the aesthetics of a room‘s design. However, the visual impact can be
minimized by a number of methods, including covering the speakers with an acoustically
transparent façade. Any material that is being considered should be tested for sound transmission
prior to installation.
Then again, hiding the system is not always best, nor is it popular anymore. Some loudspeakers,
such as vertical line arrays and other cleanly rigged systems, may be acceptably exposed. In fact,
the loudspeaker design and colour can be effectively incorporated into the overall room design to
complement other elements and overall form. Whether speakers are hidden or exposed, identifying
any visibility issues early in the design process can enhance the total ambience of the facility, both
visual and acoustical.
44
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Pattern Control and Loudspeaker Size
Sound system designers choose loudspeakers whose coverage patterns match the listening area.
Poor pattern control results in uneven sound coverage, a tendency for the sound system to feed
back, destructive multiple reflections, tonal irregularities, and poor intelligibility.
Unfortunately, it typically takes large speakers to control coverage over a wide spectrum, down to
a low enough frequency. Loudspeaker engineers generally achieve controlled coverage via horns
or loudspeaker driver-spacing interaction. Both require the speaker to be large in order to achieve
good pattern control.
Point-and-Shoot and Vertical-Line-Array Loudspeakers
There are many different types of loudspeakers and speaker arrays, each with its own pros and
cons. Point-and-shoot loudspeakers are traditional speakers, each covering a certain area of the
audience. They can be used singly or in arrays of multiple loudspeakers. However, arraying
requires a thorough understanding of loudspeaker array theory, because unintended wave interactions can create problems.
Vertical-line-array loudspeakers are becoming popular in installed applications due to improved
front-to-back evenness of coverage and narrow vertical coverage angles, resulting in increased
throw distances and less leakage of sound to the stage and ceiling. Line arrays tend to be more
expensive and may not be appropriate for certain spaces. Special problems arise in shallow rooms,
where the stronger throw of sound to the back wall produces undesirable reflections, and narrow
rooms, where the typically wide horizontal coverage angles of these speakers tend to splatter
sound onto the sidewalls.
The set of minimum acoustic requirements that are met by a working auditorium starts with the
direct sound from the speaker being loud enough which means it replicates conversational sound
levels. The background noise in the hall has to be fairly quiet and the hall acoustics should be
fairly free from echoes and other types of late reflections. (Noxon, A., 2002).
45
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
(a)
(B)
Fig 2.17:
a) Direct signals leave the speakers and impact the audience.
b) Indirect signals are those that bounce off nearby surfaces into the audience.
In terms of design for early reflection in auditorium, the philharmonic established a major shift in
approach. With overhead reflection becoming unacceptable, the subdivided audience offers for
this reason a valuable solution to the problems of large concert hall design.
Cremer‘s design schemes since the philharmonic continue to employ intriguing ways of providing
reflections in larger halls (cremer, 1989). The early reflections now tend to be lateral. Two theory
scheme discussed in this chapter, have both been exploited in real halls. The hexagonal and
trapezium terraced halls. These halls inevitably rely on reflections from quite shallow surfaces
between seating blocks, from which low frequencies are unlikely to be reflected. Cremer was less
concerned than some who consider low frequencies crucial to the sense of spatial impression. This
matter has yet to be conclusively resolved by research.
46
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Wave propagation: pressure levels (Sound pressure)
In fluids such as air and water, sound waves propagate as disturbances in the ambient pressure
level. While this disturbance is usually small, it is still noticeable to the human ear. The smallest
sound that a person can hear, known as the threshold of hearing, is nine orders of magnitude
smaller than the ambient pressure. The loudness of these disturbances is called the sound pressure
level (SPL), and is measured on a logarithmic scale in decibels.
Physicists and acoustic engineers tend to discuss sound pressure levels in terms of frequencies,
partly because this is how our ears interpret sound. What we experience as "higher pitched" or
"lower pitched" sounds are pressure vibrations having a higher or lower number of cycles per
second. In a common technique of acoustic measurement, acoustic signals are sampled in time,
and then presented in more meaningful forms such as octave bands or time frequency plots. Both
these popular methods are used to analyze sound and better understand the acoustic phenomenon.
The entire spectrum can be divided into three sections: audio, ultrasonic, and infrasonic. The audio
range falls between 20 Hz and 20,000 Hz. This range is important because its frequencies can be
detected by the human ear. This range has a number of applications, including speech
communication and music. The ultrasonic range refers to the very high frequencies: 20,000 Hz and
higher. This range has shorter wavelengths which allow better resolution in imaging technologies.
Medical applications such as ultra- sonography and elastography rely on the ultrasonic frequency
range. On the other end of the spectrum, the lowest frequencies are known as the infrasonic range.
These frequencies can be used to study geological phenomena such as earthquakes.
Analytic instruments such as the Spectrum analyzer facilitate visualization and measurement of
acoustic signals and their properties. The Spectrogram produced by such an instrument is a
graphical display of the time varying pressure level and frequency profiles which give a specific
acoustic signal its defining character.
47
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Divisions of Acoustics
The table 2.3 below shows seventeen major subfields of acoustics established in the PACS
classification system. These have been grouped into three domains: physical acoustics, biological
acoustics and acoustical engineering.
Physical acoustics
Acoustical
Biological acoustics
engineering

Acoustic
measurements and

Bioacoustics

Musical acoustics
acoustics

Physiological acoustics
Nonlinear acoustics

Psychoacoustics
Structural


Aero acoustics

General



linear
instrumentation
Acoustic signal
processing

Architectural
acoustics
Speech
acoustics and vibrati
communication (production
on
;
Underwater sound


Environmental
acoustics
perception; processing and
communication systems)

Transduction

Ultrasonic

Room acoustics
Transduction in acoustics
A transducer is a device for converting one form of energy into another. In an acoustical context,
this usually means converting sound energy into electrical energy (or vice versa). For nearly all
acoustic applications, some type of acoustic transducer is necessary. Acoustic transducers include
speakers, microphones, and hydrophones. These devices convert an electric signal to or from a
48
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
sound
pressure
wave.
The
most
widely
used
transduction
principles
are electromagnetism, electrostatics and piezoelectricity.
The transducers in most common speakers (e.g. woofers and tweeters), are electromagnetic
devices that generates waves using a suspended diaphragm driven by electromagnetic vice coil,
sending off pressure waves. As the sound wave strikes the microphone's diaphragm, it moves and
induces a voltage change. The ultrasonic systems used in medical ultrasonography employ
piezoelectric transducers. These are made from special ceramics in which elastic vibrations and
electrical fields are interlinked through a property of the material itself.
2.8 THEORETICAL FRAMEWORK
Acoustics is the interdisciplinary science that deals with the study of all mechanical waves in
gases, liquids, and solids including vibration, sound, ultrasound and infrasound. The application of
acoustics can be seen in almost all aspects of modern society with the most obvious being the
audio and noise control industries. So it is no surprise that the science of acoustics spreads across
so many facets of our society—music, medicine, architecture, industrial production, warfare and
more. Art, craft, science and technology have provoked one another to advance the whole, as in
many other fields of knowledge. Lindsay‘s 'wheel of acoustics' is a well accepted overview of the
various fields in acoustics.
Given a foundational and in-depth knowledge on the study, some of the past events on acoustics
and Architectural, application of Acoustics in building and historical development of conference
are reviewed. It also provides basic background on the science and measurement of sound, as well
as insights into some of the principles of wall partition and ceiling system acoustical design.
“We shape our buildings and afterward our buildings shape us” (Churchill, 1924).
Theoretical proponents
According to de Lange and Booij, insisted on vertical planes at different heights in the audience to
discover the lack of existing recommendations regarding the appropriate shape for a theater
enclosure. In considering this problem, he developed a new theory proposing that lateral
49
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
reflections were the most important single component of the early reflection sequence‘ the theory
provided a further explanation for the subjective superiority of classical concert halls, the
Christchurch town hall of 1972 was the first product of the hypothesis, as acoustic design, it was
not timid. (Architectural Acoustics: principles and practical by William j. Cavanaugh,)
Architects warren and Mahoney had proposed a near elliptical plan with a cantilevered gallery.
The theory specified a flat central stalls floor. The elliptical plan has the particular visual virtue
that from opposite the stage one tend to ‗convert‘ the form into a circular one, providing a
desirable illusion of proximity to the stage.
According to W.A. Allen, he carefully developed a design with individual seating groups in the
gallery for each vertical wall element. He shows how each seating group engenders three
reflecting surfaces: an inclined balcony front to reflect sound into the central stalls, a gallery soffit
to enhance reflections to the overhung seats and, most significant, a large suspended reflector
providing lateral reflections both into adjacent gallery seating areas and into the stalls. Two of
these elements also serve an essential masking function to avoid focusing by the elliptical plan.
At stalls level the seat rake and soffit design sufficiently limit the exposed wall height;
immediately above balcony seating but below the reflectors the surfaces are treated with
absorbent. Orientation of the gallery reflectors was refined with both scale and computer models.
Opposite the stage it was found necessary to use dihedral reflectors in order to achieve reflections
from the side. The volume above the reflectors is substantial; it were measured in 1983(and
thought to be more reliable than those quoted by Marshall (1979) owing to a superior sound
source. Particularly marked is the difference between the early decay time (EDT) and
reverberation time, with the EDT being only 82% of the latter at mid-frequencies. In subjective
terms this explains why there is no sense of excessive reverberation. It probably occurs because a
high proportion of sound leaving the source is reflected on to absorbent seating. It suggests that in
designs of this nature a long reverberation time is not a luxury but is essential. In line with the
shorter relative EDT, there is a high value for the objective clarity. Analysis shows that this is
mainly caused by a low level of late sound relative to theory. The measured total sound level is
less than theory, but with such a wide discrepancy between reverberation time and early decay
50
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
time, time the validity of the theory is somewhat compromised. Total sound values are all however
above the 0dB criterion.
According to Michael jarzabkowski, he says when a building planning begins, a new facility, the
quality of the listening environment should be given high priority. Its scientific investigation
should begin during the preliminary design stage before plans are committed to blueprints. At the
same time seating capacity is being decided, acoustic design of the auditorium should begin taking
a lead position in determining the layout and shape of the building. Apart from dimensional ratios,
the Plan shape of the auditorium also needs to be considered in the preliminary design stage.
Numerous Plan shapes have been used in auditorium design, from the traditional cruciform to
rectangles, squares, circles, fans, pentagons, hexagons, other polygons and various irregular
shapes.
Fig 2.18: Plan shapes
Sources: Website home1.gte.net/mjarzo
51
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Shoebox Plan/rectangle
The shoebox is basically a rectangular shaped design having the stage being a whole bay of the
width of the rectangle. The possibility of seat arrangement should be to flow with the shape and
this has its own advantage as well as disadvantage.
This is the most common plan shape for multi-purpose halls and therefore mostly used in hotel
designs (Fig 2.18). It could have flat floors and thus the seating arrangement can easily be changed
to suit other uses. This plan shape is easily divisible by partitions into smaller halls; Rectangular
halls most times are used in designs for maximum flexibility, with loose tables and movable stages
and platforms. This type of plan shape however has inherent problems, which include the problem
of obscuring lines and lateral sound reflections crossing from wall to wall which produce standing
wave resonance and echoes, unless the side walls are made diffusive or absorbent.
Yet on balance it was felt that the sound quality associated with the rectangular plan was to be
preferred. In the rectangular hall, not only are there no concave surfaces likely to create serious
echoes but ‗in addition it has the possible advantage that there is more cross-reflection between
parallel walls which may give added ―fullness‖ (parkin et al‘, 1953). The solutions involved a
synthesis of the rectangular plan with long sections responding to more recent trends.
The Three British hall is all treated in some detail, so it is appropriate here to consider
philosophies rather than detailed achievements. All three halls are rectangular in plan, though with
widths significantly larger than their classical farebeats: 32m in the festival hall, for example, in
case of the London hall, there was an interesting attempt at overcoming the limitations of a fixed
reverberation time. Bagenal hoped to avoid the perceived conflict between requirements for choral
and instrumental music. With an optimum reverberation time for instrumental music, the acoustics
are too dry for choral works, while with the optimum time for choral music the sound would be
too reverberant for the orchestra alone. By designing for a long reverberation time but profiling
surfaces near the source (in this case the ceiling) to give enhanced early reflections, it was hoped
to have both clarity and reverberation. It was bold proposed which would have worked had the
reverberation time been long enough. Before long others were attempting to pull off the same
trick, but for slightly different reasons.
In the event, the Royal Festival Hall and to a lesser extent its British contemporaries all suffer
from inadequate reverberation. The designers were wise to rely on the rectangular plan, but it is
52
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
clear that they were obliged in each hall to make compromises to accommodate high audience
numbers.
While the British designers in 1951 had retained from the rectangular plan form in the (correct)
belief that this was a salient feature of their acoustic success, the Gottingen acoustics group in the
1950s isolated the diffusing nature of the wall surfaces of the nineteenth century halls as crucial as
their success. There were persuasive logical reasons behind their argument. Fundamental to a good
environment for hearing music is an acoustical ‗sense of space‘. The listener should feel that the
concert hall is responding to the sound produced by the musicians and hear reflected sound from
all directions. This spatial sensation is of course particularly marked in large Hall.
Despite of these problems facing auditorium, many of the controlling parameters should adopted
in very beginning design to avoid an acoustical monstrosity.
Fan/ Trapezoidal Shape
This shape plan enables the maximum numbers of seats to be concentrated within the arcs giving
the best viewing conditions (Lawson, 1981). Here, rows of seats are set in concentric curves to
provide each with a forward facing view of the stage or if dividing aisles are provided the side
rows may be set at an angle to the longitudinal axis. The walls here can add to sound
reinforcement by not allowing the angle of splay of each wall exceed 25°. This is achieved by
using serrated or faceted walls, or by introducing vertical panels inclined at a smaller angle to the
longitudinal axis. In a wide hall these side sections of seating may also be separated and raised to a
higher level than those in the centre, in order to create variety in seating as well as more even
lateral distribution of sound. The rear of the wall can be straight or concave to conform to the
seating layout. The fan shaped plan is mostly used for lecture theatres (Fig 2.18).
Diamond/Hexagonal Shape
This shape plan and its extended or modified forms, has been used extensively as the basic plan
shape for multipurpose halls because it provides compromise, giving good direct sound,
controlling ceiling and lateral reflections and scope of variations in seating arrangements and
levels within the auditorium (Fig 2.18).
Circular or Oval Plans
53
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Arenas and coliseums are used for major conventions and congress meetings, in addition to
serving a wide range of community needs such as indoor recreation and competitive sports,
expositions, displays, rallies and pop concerts (Lawson, 1981). This type of arrangement requires
the installation of complex loudspeaker systems to enable the participants hear what is being said
(Fig 2.19).
Fig 2.19: Circular or Oval Shaped plan
Of these, the most solid choices are fans, rectangles and modified polygons; square is acceptable if
the auditorium is large enough; while cruciform and round shapes are the hardest to design for
good acoustics. After all, the cruciform is actually four rooms joined together in the form of a
cross, so sound from each section affects hearing in other sections. The problem with round or
partially round rooms is that the walls will reflect the sound waves to focus on a particular point.
This is similar to the way a semicircular reflector in a flashlight focuses light rays into a narrow
beam. (Michael Jarzabkowski, November 2000)
The most obvious problem with the fan shape is that the rear auditorium wall is automatically
generated as a concave curved surface, which produces a focused echo back to the stage. There is
a simple remedy for this in tilting it to reflect sound down on to the audience. Fragmenting the rear
wall surface to make it diffusing or placing absorbent on it have often been used but if the degree
of focusing is too great, echoes may still be audible. Of these remedies, only by rendering the
54
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
surface diffusing is the rear wall retained as reflecting. As a major bounding surface it is desirable
that it should not absorb acoustic energy.
One of the acoustic characteristic therefore of this plan form is a limited degree of spatial
impression. The acoustic imperfections of the fan shape also extend to the later part of the received
sound. Whereas in the rectangular plan there is vigorous inter-reflection of sound between the
parallel side walls, the potential for multiple reflections is much reduced in the fan shape. In view
of the totally different forms developed historically for drama theatres and concert halls, this was a
blinkered view. In the 1920s a new art form developed with its own auditorium: the acoustic
requirements for cinema are not particularly stringent and in order to maximize the audience size
the obvious plan form was the fan shape. Inevitably the fan-shape plan was adopted for the concert
of feeling surrounded by sound. It also leaves a low level of late sound towards the rear of the hall,
Strom and Sorsdal 1968 report from computer studies a lack of mid-period reflections (40-180ms)
in fan-shape designs. This may contribute to an early decay time shorter than the reverberation
time sensation. The degree to which a fan-shape plan suffers these various deficiencies is influence
predictably by the angle of fan; larger angles of fan have more extreme acoustics. (Architectural
Acoustics: principles and practical by Willian J. Cavanaugh,)
Fig 2.20: plan shown fan-shape
55
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Sources: www.Architectural Acoustics.com
Igbo Performing Arts
The Igbo people have a musical style into which they incorporate various percussion instruments:
the UDU, which is essentially designed from a clay jug; an EKWE, which is formed from a
hollowed log; and the OGENE, a hand bell designed from forged iron. Other instruments include
OPI, a wind instrument similar to the flute, IGBA, and ICHAKA.
Plate 2.1A contemporary Igbo masquerade, Umuahia
Source: Wikipedia
Another popular musical form among the Igbo is Highlife. A widely popular musical genre in
West Africa, Highlife is a fusion of jazz and traditional music. The modern Igbo Highlife is seen
in the works of Dr Sir Warrior, Oliver De Coque, Bright Chimezie, and Chief Osita OSADEBE,
who were among the most popular Igbo Highlife musicians of the 20th century. Masking is one of
the most common art styles in Igbo land and is linked strongly with Igbo traditional music. A
mask can be made of wood or fabric, along with other materials including iron and vegetation.
Masks have a variety of uses, mainly in social satires, religious rituals, secret society initiations
(such as the EKPE society) and public festivals, which now include Christmas time celebrations.
56
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Best known are the AGBOGHO MMUO (Igbo: Maiden spirit) masks of the Northern Igbo which
represent the spirits of deceased maidens and their mothers with masks symbolizing beauty.
Plate 2.2 the Agbogho mmuo mask. Source: Wikipedia
Other impressive masks include Northern Igbo IJELE masks. At 12 feet (3.7 m) high, IJELE
masks consist of platforms 6 feet (1.8 m) in diameter, supporting figures made of coloured cloth
and representing everyday scenes with objects such as leopards. IJELE masks are used for
honouring the dead to ensure the continuity and well-being of the community and are only seen on
rare occasions such as the death of a prominent figure in the community.
There are many Igbo dance styles, but perhaps, Igbo dance is best known for its ATILOGWU
dance troops. These performances include acrobatic stunts such as high kicks and cartwheels, with
each rhythm from the traditional instruments indicating a movement to the dancer.
57
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Key Igbo traditions & cultures:
•Kola nut
•Libation
•Wearing wrapper and head scarves
•Masquerades & Musical Instruments
•Traditional wedding process
•Traditional burial process
•Traditional title holders - ―ICHI OZO‖
KOLA NUT
Kola nut is a cultural icon believed to be the harbinger of peace and social harmony. There are
many varieties of the red or white Kola nut, which is produced by a tropical tree of the
straculliacea family known to be a native of West Africa. In many households, the sharing of kola
nuts is akin to the enactment of life-long friendship. It is also offered to the gods and spirits of the
ethereal world that are eternally bonded with the folks. "He who brings kola brings life", is a
popular saying of the Igbos made popular in Things Fall Apart, the epic novel of world renowned
writer, Chinua Achebe. This proverb reflects the importance attached to the kola nut in Igbo
society. There is actually a popular saying, especially among Nigeria's three major ethnic groups -which says, "the Yorubas produce kola, the Hausas chew it and the Igbos celebrate it.‖
LIBATION
The Libation ritual called ITU NMANYA precedes all traditional Igbo public and private events,
including weddings, meetings and other get-together. Libation with Palm wine (or any wine) is a
symbol of intimacy with the ancestors and harmony with the living. The invocation over the palm
wine is a superficial symbol of imploring for an intimate spiritual grace of a providential God at
events where individuals share a feeling of purity, protection and hope. During ceremonies, the
58
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
elder pours a libation with the wine on the floor or ground, which symbolizes the safe cyclic
passage of the forebears from the spirit land to the physical world.
MASQUERADES
In Igbo culture, the masquerade embodies the spirit and human worlds. The mystique surrounding
the masquerade is one the key components of the Igbo culture that survived Western influences. It
is generally believed in the Igbo land that the masquerade is a spirit which springs from the soil.
Depending on your point of view, it may be true or only a myth. The masquerades are classified
into categories based on specialization. Each masquerade possesses particular attributes (warriorlike prowess, mystical powers, youthfulness, and old age) and specializes in one or more skills
(dancing skills, acrobatics, and other ritual manifestations). Masquerading may involve one person
or a team made up of instrument players, vocalists, dancers, masquerade advisers, and the
masquerade itself. Our four masquerades are: AGABA, ODOGWU, OJIONU and ABRIBA war
dance. The masquerade appears during traditional celebrations such as funerals, new yam festival,
and special holidays such as Christmas and New Year.
Ijele masquerade (Mmọnwụ Ijele)
The IJELE masquerade is a peculiar type of masquerade. It is such a popular masquerade that its
fame is felt in every part of Igbo land. Thus the Igbo proverb that says, ―ijele pụta ụmụ obele
mmọnwụ alaa‖, (when the IJELE appears, the small masquerades disappear), lends credence to
this. The IJELE masquerade is most popular in Anambra State, and to some extent, Enugu State.
The IJELE masquerade has the onerous role of entertaining people during occasions.
This
masquerade is very big and completely adorned. That is why everything about the masquerade is
very costly. Consequently, any person or group of persons who want the IJELE masquerade to
entertain people for him or them during any occasion, such a group is hosting, and such a person
or group pays the IJELE group a specified amount of money (and some other items).
Akwụnaechenyi
Akwụnaechenyi is another complex and costly masquerade like the Ijele masquerade.
Akwụnaechenyi is very like the IJELE masquerade in appearance, to the extent that a non-initiate
can even confuse it with the IJELE. Some people even say that Akwụnaechenyi is the female
59
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
specie of IJELE. Like the IJELE masquerade, terms and condition of its performance hangs on the
bargaining force of the bargainer and the Akwụnaechenyi group. Again, like the IJELE, and other
masquerades, Akwụnaechenyi masquerade can perform during OFALLA, condolence visits, burial
ceremonies, outing ceremonies, during festivities etc.
Mkpamkpankụ
Mkpamkpankụ is a very serious, fully masculine-featured masquerade. Mkpamkpankụ is brisk,
aggressive, agile and notorious in its own way.
It has the appearance of a person.
This
masquerade is active to the extent that about two or more strong men is ever around it to with the
rope that is tied around its west to draw it back from over acting. Again, as usual, before
Mkpamkpankụ displays, the person who needs the entertaining service of Mkpamkpankụ
masquerade must have to bargain with the mkpamkpankụ masquerade group.
The Okwomma Masquerade
This is the type of masquerade that has similar features with the the Mkpamkpankụ. What makes
the Okwomma very peculiar is the fact that it always has a short matchet in hand. It uses this
matchet to shake hand, to collect money and to greet people. Again, like the Mkpamkpankụ, it is
usually prevented from overacting with the heavy rope that is tied on its west.
Agaba Masquerade
The AGABA masquerade as a character is that of a warrior represented in its name that literally
connotes ―let‘s go‖. The AGABA major attribute is warrior-like prowess, which specializes, in
ritual manifestations. The ease in the mobility of the Agaba instruments (can play with the
OGENE only) makes it a popular masquerade for the youths residing in major cities of the
Igboland. The chanting that accompanies the Agaba cut across ethnic dialects and cultures among
the Igbos.
60
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Plate 2.3 Odogwu Masquerade. Source: Wikipedia
The ODOGWU masquerade is a youthful and aggressive character represented by a mask that
insinuates ―Bloodshot eyed rebel‖. Its major attribute is demonstration of youthfulness with
specialty in intimidation. The ODOGWU is also known for the highly charged chanting that
accompanies its rhythms.
61
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Plate 2.4 Ojionu Masquerade. Source: Wikipedia
Ojionu Masquerade
The OJIONU masquerade is a water spirit character represented by a headdress of crocodiles,
sharks and other predatory water creatures. There may be more than one masquerade depending on
the occasion. The instruments players vary from five to ten performers. One of the eye catching
features of the OJIONU is its wooden trunk. The trunk is used to keep all its mystical and gyration
gears as well as a seating bench for a quick rest. The drummers play two primary roles – one plays
non-stop providing the base and the other alternates and the alternating rhythm is what the
masquerade dances to. The masquerade also dances to the OJA (flute) when that is present.
The major attribute of OJIONU is creative non-stop dancing. Versions of the OJIONU
masquerade varies from those that perform voices only and possess superior mystical powers to
those that dance predominantly with minimal voices and less mystical powers.
62
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Abiriba War Dance
This is a war dance troupe represented by two distinct symbols of war – the lead warrior carrying
the small drum filled with overflowing wine for imbibing and incantations and the medicine man
carrying the three skulls symbolizing the spoils of past wars and as a warning to future foes.
This masquerade is unique since it‘s not covered with costumes and mask as others. The
masquerade has a piece of palm tree leaf in his mouth to prevent him from talking thus ensuring
the integrity of its mystical powers.
The players use a combination of flat wooden clappers and drums to produce non-stop rhythms.
The lead warrior leads the chanting while the players and the other dancers sing the chorus.
Attributes – mystical powers and charged atmosphere, Specializes in intense motivation and
dancing.
Plate 2.5 the Abriba war dance troupe
Atilogwu
ATILOGWU is a traditionally spirited youth dance from the Igbo ethnic group of Nigeria that
focuses on vigorous body movement and often includes acrobatics. In the Igbo language, the word
itself ―ATILOGWU‖ translates into ―has magic—as in sorcery/ witchcraft. The name stems from
rumours that bewitchment or magic potions had to be involved if the children of the village could
63
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
perform so exuberantly and energetically, while making it look so effortless. The tempo of the
dance matches the tempo of the music, which is dependent on the beat of the drum and ―OGENE,‖
a metal gong instrument. The dance is usually performed during festivals and the festivity will also
include exotic dishes created from authentic Nigerian recipes, served buffet style.
Plate 2.6 the Atilogwu dance troupe. Source: Wikipedia
Musical Instruments
The Igbo people have a melodic and symphonic musical style, into which they incorporate various
percussion instruments: the UDU, is essentially designed from a clay jug; an EKWE, which is
formed from a hollowed log; and the OGENE, a hand bell designed from forged iron. Other
instruments include OPI, a wind instrument similar to the flute, IGBA, and ICHAKA.
The EKWE (Silt-drum) is a tree trunk, hollowed throughout its length from two rectangular
cavities at its ends and a horizontal slit that connects the cavities. The size of the slit-drum depends
on its use and significance.
64
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Plate 2.7 the Ekwe. Source: Wikipedia
The OGENE (Gong) is metal instrument. They were made originally in bronze but, in modern
time, are mainly made out of scrap metal as a bulging surface in elliptical shaped rim, and tapering
like a frustum to its handle. It is hit about its rim by a stick to produce different tunes.
Plate 2.8 the Ogene. Source: Wikipedia
The OJA (Flute) is a piece of wood designed with a cavity inside, the top has a wide opening to fit
the shape of the human lower lip, a small hole on the bottom and two smaller holes closer to the
top on exact opposite side.
65
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Plate 2.9 the Oja (flute) Source: Wikipedia
The IGBA (Cylinder-drum) is a piece of hollow wood covered at one end with animal hide held
down tight with fasteners. The artist carries it over his shoulder with the help of a shoulder strap.
The artist produces the sound by beating on the animal hide with his fingers or combination of one
set of fingers and a special stick.
Plate 2.10 the Igba (Drum) Source: Wikipedia
66
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
REFERENCES

Beranek (1979) (Original Edition 1962). Leo L. Beranek, Music, Acoustics &
Architecture. Cambridge, MA: Courtesy Leo L. Beranek.

Beranek (1996). Leo Beranek, How They Sound, Concert and Opera Halls. © 1996,
Woodbury, NY: Acoustical Society of America.

Bagenal (1931). H. Bagenal and A. Wood, Planning for Good Acoustics. Methuen,
London.

Breton (1989). Gaelle Breton, Theaters. New York, NY: Princeton Architectural Press,
Paris, France: Editions du Moniteur.

Cavanaugh, William J., and Joseph A. Wilkes (1999), eds. Architectural Acoustics:
Principles and Practice. New York: John Wiley & Sons,

Cremer (1982). Lothar Cremer and Helmut A. Müller, Principles and Applications of
Room Acoustics, vol. 2. New York, NY: Applied Science Publishers.

Churchill, W. (1924). Address to the Architectural Association at the annual distribution of
prizes in 1924. Architectural Association Quarterly, 5:44–46.

Forsyth (1985). Michael Forsyth, Buildings for Music. Cambridge, MA: MIT Press.

Garnier (1880). C. Garnier, Le nouveau Opéra de Paris, 2 vols. Ducher et Cie, Paris.

Guillen (1995). Michael Guillen, Five Equations that Changed the World: The Power and
Poetry of Mathematics. Hyperion.

Hunt (1964). Frederick V. Hunt, ―Introduction to Dover Edition,‖ Collected Papers on
Acoustics by Wallace Clement Sabine. © 1964, New York, NY: Dover Publications.

Ingard (1994). K.U. Ingard, Notes on Sound Absorption Technology. ver. 94–2, © 1994,
Kittery Point, ME: K.U. Ingard.

Izenour (1977). George C. Izenour, Theater Design. New York, NY: McGraw-Hill. The
George C. Izenour Archive at Penn State University.

Lindsay (1966). Bruce Lindsay, ―The Story of Acoustics.‖ Reprinted with permission from
J. Acoust. Acoustical Society of America: Melville, NY.

Marshall (1967). A. Harold Marshall, ―A note on the importance of room cross-section in
concert halls.‖ Journal of Sound and Vibration. 5,1967.
67
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE

Pierce (1983). John R. Pierce, from The Science of Musical Sound by John R. Pierce ©
1983 by Scientific American Books. Used with permission by W.H. Freeman and
Company.

Sabine (1922, 1964). Wallace Clement Sabine, Collected Papers on Acoustics. New York,
NY: Dover Publications.

Skudrzyk (1954). Eugen Skudrzyk, Die Grundlagen der Akustik. Wien: Springer-Verlag.
68
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
CHAPTER THREE
GENERAL GUIDELINES AND DESIGN CONSIDERATIONS
69
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
CHAPTER THREE
3.0 GENERAL PRINCIPLES AND DESIGN CONSTRUCTION
There are universal laws guiding the design of several spaces, sometimes their similarity leads to a
harmonized analysis while at other times the considerations are wide apart. Many of such
principles are controlled by building regulations and ordinances, yet flexibility is needed to
accommodate likely future change while social orientation and public enlightenment is a major
design criteria. The building should be able to give optimum cultural satisfaction. The choice of
site steers the matter of its location, where several possibilities are available together with the
drawbacks and advantages of each that must be carefully weighed. And this calls to mind as to
whether to have the performing Arts theatre right at the city centre or at the city periphery.
Performing arts theatres tend nowadays to be regarded more and more as "cultural theatre." It must
therefore be remembered that as such they are visited not only by local residents but by tourists
with different backgrounds who, if the theatre is near enough and easy to reach, may come to it,
even with little time to spare, in search of instructive recreation.
Most times, it is convenient to have such a theatre right at the city centre for convenience where it
is possible to be within walking distance and within easy reach of hotels, colleges, university,
offices, market place and libraries. But on the other hand, one might reconsider due to traffic
influx and congestion of the city centre, making the choice of site very critical and an important
issue.
Naturally, for the building to be symbolic, it has to touch on the culture of the people of the area in
question (Enugu state) which will considerably affect the building form and size of the interior
spaces.
A performing Arts theatre must be planned not only in relation to its purpose, quality and type of
its exhibits, but also with regard to certain economic and social considerations. For instance, if it is
to be the only institution in the town which is suitable for a number of cultural purposes (theatrical
live performances, concerts, exhibitions, etc.) it may be desirable to take account in the initial
calculations of the financial resources on which it will be able to rely, the nature of the local
population, the trend of development of that population and the proportion of the population which
is interested in the Arts theatre. Having this in mind, therefore, the arts theatre should be imposing
in appearance, solemn and monumental. The worst of it is that this effect is often sought through
the adoption of an archaic style of architecture. We are all acquainted with deplorable instances of
70
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
new buildings constructed in imitation of the antique; they produce a markedly anti historical
impression, just because they were inspired by a false view of history. Another outmoded
prejudice is that which demands s "classical" setting for ancient works of art, as though their
venerable dignity would suffer and their aesthetic value be diminished if they were placed in
modern surroundings.
In other words we must not devote our entire effort to designing spaces which will be
architecturally pleasing; it is most important that adequate attention should also be devoted to the
facades of the building, that their massing valour be ensured and their predominance established,
in other to create an impressive environment.
Accessibility needs (access), parking spaces, circulation (both internal and external) are part of the
factors to be considered in the design.
3.0.1Access
Accessibility should be direly considered with the entry point(s) clearly defined and convenient to
users. Provisions should be made for people with private and public vehicles as well as pedestrian
pathways. Maintenance routes need not to be forgotten for goods and services such as equipments,
food item, furniture, and even for disposal of wastes.
Drop-offs for visitors are to be put into consideration as this will help protect people from the
harshness of the weather. The entrance should be large, allowing for the passage of a large number
of people and the movement of large objects such as furniture and equipment. Ramps must be
provided at the entrance for the aged and disabled. Important design features for access drives
should also include lines of sight to enable oncoming traffic to be seen as vehicles leave the
premises, radii of curvature for bends and turning areas to be appropriate for the size and turning
circles of the vehicles using the road (trucks, cars, buses and vans), dimension of roads to allow
for passing, waiting, unloading passengers and goods where these take place.
3.0.2Lighting
Intelligently used daylight makes first-class architecture stand out and enhances any building.
Daylight is about more than just achieving a ―feel-good‖ ambience; it can also help save energy by
reducing the amount of artificial light used to a bare minimum. Besides excellent lighting quality,
71
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
conservation aspects, in particular, must not be overlooked in buildings. Intelligent lighting control
systems are indispensable in this respect. They make it possible to precisely determine the amount
and intensity of daylight and artificial light.
The eyes are made to articulate the varying intensities and qualities of light energy which is
reflected from an object that is being perceived. Human eyes can only appreciate form, texture and
colour in light. Illumination of objects is therefore of uppermost importance especially in
performing spaces. Therefore in architecture, light is needed to perform the following important
functions of revealing the colour, form and size of the building elements in terms of proportions of
the spaces; to facilitate the sight, accuracy and the rate of recognition of an object (this depends on
the quality and degree of illumination); to facilitate and ensure that the operation of various tasks
and the safety of people is guaranteed. Natural or Day lighting is very important in Arts theatre
design and should be given proper attention.
Windows can be placed at certain levels on the walls to allow natural illumination. A disadvantage
of windows placed on ordinary levels is that it causes direct glare (depending on where it is
placed). An advantage of windows placed at the ordinary level is that some of them can be fitted
with transparent glass, allowing pleasant views of the countryside, gardens, or architecturally
interesting courtyards. This provides a diversion, resting the visitor's eyes and refreshing his mind.
Lighting methods
The following figures illustrate lighting methods for an enclosed space and it should be
considered:
72
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig 3.0: Lighting installed so that angles of incidence correspond with natural light
Source: (Neufert, 2001)
Fig 3.1: Exhibition room with side lighting
Source: (Neufert, 2001)
73
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig 3.2: Horizontal Lighting
Source: (Levin, 1983)
Advantages of Vertical Lighting

The wall spaces can be increased as the need for windows does not arise
74
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE

It provides a steady supply of light because the level of illumination is unaffected by the room
layout.

The use of vertical lighting enhances centre for art and culture security as entry will have to be
from the top

Uniformity in the degree of lighting to produce good visibility with minimum distortion and
reflection
Disadvantages of Vertical Lighting

The transparent surface requires constant maintenance to remove dust from time to time

The light produced looks brighter than the displayed objects.

The exhibition space tends to lose the excitement due to the uniform illumination.
Advantages of Horizontal Lighting

It allows the lateral integration of the interior with the exterior spaces

Affords the Architect the opportunity of combining natural lighting with natural ventilation.

Activates the plastic and luminous qualities of the exhibits.

It brings about simplicity in design and also offers low cost potentiality.
Disadvantages of Horizontal Lighting

There is loss of display areas because of the openings on the walls.

It causes distraction to the visitor
Artificial lighting
Artificial light is obtained from a fixed or movable point or source which does not constitute
intense diffusing surfaces as the daylight (Plates 3.9 and 3.10). It offers a great deal of flexibility
in application and can be designed to produce a wide range of qualities and levels of illumination.
The level of illumination can be stabilized as the space to be illuminated may require.
This is the use of artificial light in large spaces without any special provision for the local
requirement.
75
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig 3.3: Wall floodlights: direct illumination
Fig 3.4: Direct symmetrical illumination
Source: (Neufert, 2001)
The use of artificial light in a centre for art and culture has some advantages which include the
possibility to control illumination and it affords the opportunity of localizing or generalizing the
quality and the level of illumination, and finally it can create special effects on objects for the
benefit of the viewers. In spite of the obvious advantage stated, the exclusive use of artificial
lighting within the centre for art and culture interiors can contribute in the direct emission of heat
into the spaces thus calling for the maximum use of air conditioning system. This may create
unfavourable level of illumination which could be injurious to some of the centre for art and
culture collections.
Day lighting
This type integrates the consideration for local requirement with minimum level of illumination to
highlight the objects. The light can be varied from room to room by stepping ambient light levels
up and down to reduce visitor‘s boredom and fatigue.
Figure 3.5 shows top sky lighting
76
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig 3.5: Vertical Lighting
Source: (Levin, 1983)
77
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Moreover, conservation and stability requirement can be achieved with some specially designed
equipment. Filtering of light is achieved through the use of mechanical screens, clear plastic or
fabric so as to reduce the intensity of illumination on objects which are light sensitive.
Fig 3.6 shows top (sky) lighting
Fig 3.6: Top Sky lighting. Source: (Levin, 1983)
3.0.3Circulation
78
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Circulation here can be looked at in two ways, internal and external circulation. Internal
circulation involves movements along corridors and lobbies. Corridors are usually wasted space
but in this design it will be utilized to give the visitor an enthralling experience of the multiple
objects on display along it while the external circulation deals with movement outside the
building.
3.0.4Ventilation
There are basically two types of ventilation;
1. Natural ventilation
2. Artificial ventilation
Natural Ventilation
This involves the use of fenestrations and proper orientation of buildings towards the wind
direction to achieve the exchange of stack air with fresh air. It is an efficient way of stimulating
the movement of air within a space. For natural ventilation to be used in a centre for art and
culture design, the centre for art and culture designer must combat the following problems:
a. The control of the speed of air inlet
b. The level of pollutants in the air
c. Air temperature and humidity
The first problem can be handled architecturally while science will take care of the second and
third problems.
Artificial Ventilation
This involves the use of mechanical devices to achieve air movement within the desired space.
Special equipments can be used to achieve the system of artificial ventilation they are;
a. Air Filter
b. Air conditioning
c. Air Intake fans
79
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
The ventilation plants incorporate air conditioning within the system, the process of heating or
cooling, humidifying or dehumidifying filtered air to suit the climatic requirements of spaces. The
air conditioning system ensures that fresh air is evenly diffused over the entire area taking into
consideration the pre-determined humidity and temperature level adequate for human comfort.
3.0.5Acoustics
The transport of sound through structure should be controlled. Functional zones should be
provided with surface or sub-surface materials that dampen impact sounds and isolating cavities to
interrupt the structural transmission of sound. Noise levels should be controlled within zones by
appropriate choices of material finishes on floors, walls and ceilings, and the shaping of interior
spaces to prevent flutter and unwanted amplifying effects. To generalize and simplify, the
penetration of low-frequency sound is lessened by structural mass of middle frequencies by
diffusing and absorbing surfaces, and of high-frequency sound by the elimination of small-scale
air gaps in doors, windows and partition walls.
Acoustics should be considered in the design of auditoria and halls. It impacts everything from the
size and shape of the hall, the location of mechanical rooms and the selection of sound equipment
to the density of materials enclosing the hall, the sizes of ducts and the requirements for doors and
windows.
Spaces that are used for more than one type of performance require an acoustical environment that
can be varied to serve each performance appropriately. Humidity should be carefully controlled in
performance spaces. From an acoustic standpoint, the relative humidity in spaces for music should
be forty percent. Low humidity makes air more absorptive of high-frequency sound, which should
be avoided. Low humidity also creates an uncomfortable environment.
The set of minimum acoustic requirements that are met by a working auditorium starts with the
direct sound from the speaker being loud enough which means it replicates conversational sound
levels. The background noise in the hall has to be fairly quiet and the hall acoustics should be
fairly free from echoes.
Acoustical design must take into consideration that in addition to physiological peculiarities of the
ear, hearing is complicated by psychological peculiarities. For example, sounds that are unfamiliar
80
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
seem unnatural. Sound produced in an ordinary room is somewhat modified by reverberations due
to reflections from walls and furniture; for this reason, a conference centre should have a normal
degree of reverberation to ensure natural reproduction of sound. For best acoustic qualities, rooms
are designed to produce sufficient reflections for naturalness without introducing excessive
reverberation at any frequency, without echoing certain frequencies unnaturally, and without
producing undesirable interference effects or distortion.
ACOUSTIC DESIGN FOR SPEECH
There are two major considerations involved for good acoustics in an auditorium:
I. psychological conditions.
The psychological conditions have to do with human responses to sound levels, which are:
• The relationship between the speaker and the audience-This is affected by the size of the
audience, circumstances, spaciousness of surroundings, relative positions and the elevation of the
speaker.
• The levels of arousal and appreciation; this has to do with the environmental and physical
comfort, sound strength and clarity, masking, distortion and distraction.
II. Physical requirements
The acoustical design should meet the following:
• Good direct sound- This is dependent on the shape and size of the hall, the distance to the rear
and side sitting positions, row-to-row sightline clearances and the design of balconies where
provided.
• Early reinforcement of direct sound- It is achieved by the position and construction of reflecting
panels and the provision of electronic amplification.
• Freedom from discrete echoes and strong enveloping sound- This is achieved by selective
absorption and diffusion and the adjustment of reverberation for differing conditions.
81
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
• Control of noise entry- Control of masking distracting noise is affected by the planning, zoning
and separation of areas, appropriate noise insulation standards and acoustic specifications for
engineering services and equipment.
• Multi-purpose use- Acoustic regulation of speech and music includes the adjustment of the
shape, size and the electronic modification of the growth and decay characteristics of sound.
Means of Achieving Acoustics
Shape the auditorium hall in such a way that the audience will be close to the sound source.
• Raise the sound source as much as possible to achieve a free flow of direct sound waves.
• Rake or ramp the floor for better sound effect
• Surround the sound source with large sound reflective surfaces like plywood, plastics Etc.
• Shorten the distance to be travelled by direct and reflected sound by keeping the floor area and
volume of the hall to a reasonable minimum.
• Opposite and parallel plain surfaces which can set up strong reflections must be avoided.
• Concave curved surfaces should be avoided
• If galleries are required, the free height between the heads of the audience and the depth of the
seating area under the gallery should not excel twice the height.
The distances by which speech can be heard depends on the design of the auditorium and to the
extent by which the sounds are reinforced by reflection and masked by other noises. This is in
addition to the variations in the ability of the speaker to speak clearly and audibly.
Room dimension principles for good acoustics
Geometrical and statistical room acoustics as well as room acoustics rising wave theory, all lead to
results and conclusions which can be used in the construction of a room. From these, they
determine the acoustical behavior of the room:
82
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
1) The volume of the room.
2) The form of the room.
3) The reverberation time of the room.
The volume
When the volume of a room increases, then its surface are, Sand the total absorption A also
increase: As we are dealing primarily with a defined and specific sound power P, the energy
density W which exists also falls as the absorption A increases. The following relationship then
applies= W=4p/CA.
It is simple to calculate the maximum volume in relation to sound source power P from the
relationship above .By assuming average numerical values however from the numerous numerical
data; room volumes are obtained which are common to many practical experiences.
The Form
In older times the dimensional rule guiding the dimensional relationships of rooms were written.
Among these are: The golden rule; ratio 2:2:5 and ratio 1:3/4.
Today, answers can be found to the question of favourable or unfavourable room proportion from
the stand point of wave acoustics, at least for simple room forms like a rectangle. The proportions
of the sides of the parallelepiped can be selected in such a way that the eigentones of the room are
distributed as evenly as possible. Hence, it follows that integral ratios are to be avoided.
Bolt has shown that the above proportions commonly used in architecture are all within the
permissible limits in the context of modern trends of thoughts. However it is also shown that it is
completely unnecessary to keep closely to hard and fast rules, on the contrary, the room
proportions can be selected from considerable wider limits.
For a good distribution of sound there must be short unobstructed sound-path from the sound
source to all the listeners. In a room, the listener hears first the sound which reaches him by the
most direct and shortest path, followed immediately by the reflected portions which form the
reverberation. A sufficiently large rake is recommended.
Petzold specified, in his standards for sufficient seating rake, a 12 cm gap between sound rays
emanating from the source while more recent standards consider 8cm sufficient.
83
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Reverberation time
Reverberation is the upwelling and dying out of chaotic sound. Unlike reflections, which are
organized sound waves with a measurable direction and strength, the sound of reverberation has no
direction, only its loudness can be measured. Reverberation time is measure of sound or time it
takes for a sound in a space to be reduced by 60 decibels. It is a unique type of sound and remains
generally agreeable for people as long as it is not too loud or last too long.
Too much reverberation will blur words together. But there are two kinds of ―too much
reverberation‖. Reverberation can be too loud or reverberation can last too long. In a properly
designed room, the reverberation is set to the proper loudness and it is set to last the proper amount
of time.
The loudness of reverberation depends on how much sound is being dumped into the hall. Actually
that isn‘t quite true. We take the total amount of energy dumped into the hall, subtract the amount
absorbed during reflections and whatever is left over is what fills the hall and becomes
reverberation. The rate of decay of the reverberation does not depend on how loud the
reverberation is. Reverberation dies out at the same rate, dB/second, regardless of how loud or
quiet the sound happens to be. Adding acoustical material to the hall does change the rate of energy
decay in the hall, the more acoustics the shorter the decay time.
The total energy stored in the reverberant condition of a hall is equal to the how loud it is times the
volume of the hall. A large hall stores more energy than a small hall. A hall with loud reverberation
is holding more energy than if it has quiet reverberation. Reverberation energy is stored in the
volume, in the air of the hall. Reverberant energy is removed by friction between the waves and the
walls of the hall, not much different than an ocean wave the beach.
Reverberation is stored in the volume of the hall and absorbed on the surface of the hall. How long
it takes for sound to die out of a hall depends on the ratio of volume to surface area and of course
the roughness or acoustical friction provided by the walls, floor and ceiling of the hall. Once the
architectural surfaces and furnishings have contributed their percentage of acoustical friction the
reverberation time is usually still way to long. At this point acoustic materials have to be
introduced to make up the difference (Noxon).
For every room there is an optimum reverberation time. This is also dependent on the volume of
the room and the purpose for which it is meant .In many cases it is also dependent on the form and
84
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
in particular the diffusion of the room .In determining the reverberation time ,it must be decided
whether the room is to be used for music or for speech. For this the concepts speech acoustics and
music acoustics are used.
3.0.6 SOUND REFLECTORS
Sound amplification increases the sound intelligibility of halls. It should be noted that every
material and item used in construction has an absorption coefficient. People, brick, and even
windows absorb some sound. Not only does every material have an absorption' coefficient, the
amount of absorption varies with the frequency of sound. Carpets, drapes and curtains absorb'
mostly high 'frequencies while wood and thin plasters on furring strips absorb lower frequencies.
Ceiling reflectors are required for sound amplification when an auditorium is large and the
distance from a sound source to the audience seat is over 18m. The sound reflectors should be
designed to concentrate on the most distant of seats. Materials to be used should not weigh less
than 5 kg/m2 for speech only or 25 kg/m2 for music.
There are four major types of absorbent materials each differing from the others by which sound is
absorbed by each. They include:
• Porous absorbents which are best in high frequencies
• Membrane absorbents which are best at low frequencies
• Resonant absorbents can be turned to a very narrow band of any frequency.
• Perforated panel absorbents - a combination of resonant and porous absorbents, best in medium
frequencies.
It can be affected to some extent by variation of whole size, shape and spacing of backing material
and space.
85
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
MATERIALS
APPROXIMATE
ABSORPTION
COEFFICIENTS
PLASTER
0.02
FLOOR TILES (HARD)
0.03
WOOD PANELLING
0.04
WINDOW (5 MM)
0.10
CURTAIN (MEDIUM WEIGHT)
0.30
ACOUSTIC PLASTER
0.23
FIBRE BOARDS
0.32
MEDIUM
EFFICIENCY
ACOUSTIC
0.42
ACOUSTIC FELTS 12MM THICK, ON
0.47
TILES ON BATTENS
BATTENS
WOOD-WOOL
CEMENT
BOARD,
0.53
22MM THICK, ON BATTENS
SPRAYED ASBESTOS 25MM THICK
0.62
HIGH EFFICIENCY ACOUSTIC TILES
0.72
WITH PERFORATED SURFACES ON
BATTENS
Table 3.0: Sound Absorbent Coefficients of Various, Materials
86
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Sound audibility is greatly influenced by some acoustic phenomena which reduce the quality of
sound. They include:
I. Echoes
This is due to a difference in path of up to 19.8m between the direct sound and the reflected sound.
Due to this delay in the arrival of the reflected sound a listener hears two separate sounds. Ai
blurred effect is the result when the path difference is more than 15 m but less than 19.8 m as the
direct sound and reflected sound are, not heard distinctly. This problem can be solved by reducing
the path difference in the design of the room shape. Attenuation by means of absorption or
divergence also reduces this problem.
II. Sound foci
With this phenomenon, reflected sounds are brought to focus at a definite point or points. When
such occurs close to the speaker, he has the illusion of being loud and audible enough when in fact
the audience suffers as the speaker is inclined to lowering his voice. Sound foci also produce a
non-uniform distribution of sound which is highly reinforced at certain points. Concave surfaces
are the main shapes that pause this problem and consequently, they should be avoided.
III. Room flutter (multiple echo)
A pair of parallel opposite walls will result in continuous back and forth reflection of sound.
If the distance between these walls is large multiple echoes are heard. Rectangular rooms with two
parallel pair of reflective walls should be avoided' as they cause this problem. Ceilings should also
not be made parallel to the floor to avoid this problem.
IV. Whispering galleries
This is an instance of the destructive effects of reflections. Reflections from curved surfaces
especially those of high frequencies tend to creep around a large concave surface with the resulting
whisper heard distinctively 60 m away. This problem can be solved in the same way as that of
sound foci.
87
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
3.0.7 VENTILATION
To provide a conducive working environment within buildings, there has to be constant removal of
air. This is to expel stale air and replace it with fresh air. There is more to ventilation than just air
exchange, it maintains and moderates the temperature of the building spaces. Proper ventilation
mimics natural outdoor air currents, reducing levels of indoor air pollutants by continually
circulating fresh air. This process of ventilation can be carried out in 2 ways – naturally and
artificially.
Natural ventilation
Natural ventilation occurs when advantages of air movement in nature are made use of. The
prevailing winds over the site are admitted into the building through windows or other air inlets
and released through the provided outlets. The resultant in-equilibrium in air pressure outside the
building allows for the extraction or suction of the air mass that was inside previously. It occurs by
stack effect, cross ventilation, or by air passage through adjacent walls. To achieve this, the
building is oriented taking into cognizance of the prevailing southwest northeast winds. Because
ventilation is not the only factor in determining orientation, other means of inducing ventilation
should be provided.
A good understanding of orientation, geography of an area is an asset in ventilation design. In the
tropics where the site to this facility is to be located, ventilation cannot be compromised.
More so, in Nigeria, for a building to function appropriately, dependence on the supply of power
which is epileptic would make the building unusable in cases where a back up supply of power is
not available.
Irrespective of type of natural ventilation adopted, it often may be defective. This is because the
effective source of control over excessive natural ventilation is to shut out the passage of air. The
relief arising from this control is only momentary before extreme conditions of this relief set in,
thereby causing bodily discomforts.
The desired effect of ventilation within a space can be achieved by the manipulation of certain
determining factors like the size, position, and type of window openings.
88
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Artificial ventilation
This involves the use of mechanical devices such as air conditions, exhaust fans, ceiling fans, etc
to effect or force the removal of air from a space. The use of these devices is to make effective
what natural ventilation could not achieve on its own. Engineers estimate that for adequate
ventilation the air in a room should be changed completely from one and a half to three times each
hour, or that about 280 to 850 liters (about 10 to 30 cu ft) of outside air per minute should be
supplied for each occupant. Providing this amount of ventilation usually requires mechanical
devices to augment the natural flow of air.
The design should provide for sufficient ventilation of the spaces. In view of the harsh economic
situation in the country and the high cost of building maintenance, the design of this facility should
maximize the use of natural ventilation, which would be complimented by artificial ventilation.
Spaces enclosed by one or more external walls, where possible, should be naturally ventilated
while those that are completely enclosed would resort to artificial ventilation.
3.0.8 SAFETY MEASURES
Safety measures against fire outburst should be taking into considerations. As a result of disastrous
occurrences in previous designs of existing buildings, the relevant authorities in charge of
planning and design grant licenses or approvals upon the compliance with the stated safety
requirements. Most times, these guidelines are burdensome and uneconomical, but the
introduction of the safety regulations has a reduction in the disasters in modern times. The
regulations used in Nigeria are as adopted from the regulations in Britain. Perhaps the best
guarantee of public safety is the efficiency and integrity of the day-to-day management of the
facility, and this can be encouraged if those concerned have confidence and understanding of the
safety arrangements.
Most common outbreak is fire and should be considered critically for human safety purposes.
Fire safety in buildings is evaluated by careful examination of the design of the building to
determine whether the building meets the criteria set forth in the building code. The circulation,
construction type, and materials must meet standards for fire exits, fire resistivity, flame spread,
and amount of smoke produced. Failure to comply in this area can cause fires. However well
89
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
buildings are evaluated before and during construction, the use of some buildings may, in fact,
change over their useful lives. Fire exits and corridors may sometimes be used for storage or
activities instead, and wall coverings with a high flame spread can cover original and safer
surfaces. Fire doors are sometimes closed and locked for security reasons, creating a most
dangerous situation. To avoid and prevent spread of fires in event it occurs:
1. Uses of fire-resistant materials in fire-prone areas of the facility like the kitchen,
auditorium.
2. The fire authority should be consulted on the scale of provision of fire appliances and
where they should be placed in the building. Compliance with these requirements is a
condition of a grant of approval to build the facility.
3. The structural members (example: beams, columns etc) of the building should be
adequately protected from possible fire attack.
4. Satisfactory planning of buildings internally and in relation to adjacent buildings.
5. Providing alternative means of escape and clear, direct, short and unobstructed escape
routes.
6. Short travel distances to outside safe areas, fire fighting gadgets and importantly to escape
means.
7. Installation of fire fighting equipment like automatic sprinkler system, fire-fighting hose
real etc. at important locations within the buildings. All equipment should be recessed so as
not to obstruct corridors and any other routes of escape.
8.
Installation of fire detecting alarm system. It consists of a sensitive thermostatic director
heads installed inside the ceilings and connected electrically to a large alarm gong outside
the building.
9. Conduit electrical wiring should be adopted to prevent fire risk associated with naked
electric wires resulting from damage to the wires.
3.0.9DESIGN OF THE AUDITORIUM AND ITS ACOUSTICS
The maximum distance from the effective center of the stage to the furthest seat in the auditorium
has visual and acoustic limits. It varies according to the kind of activity and differs for congress,
concerts, etc. These are the two most important factors in auditorium design.
90
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Though the desired capacity and the specific function of the hall goes a long way in the final
outcome of the hall, to make an auditorium hall functional, a balance must be stuck in the
acoustics and views of the focus or stage from every point in the hall. This factors more than
others determine the design and planning of the halls. Having discussed acoustics in detail as a
planning consideration, it will also be too discussed briefly under the design of an auditorium and
sightlines would be dealt with after.
If you've ever gone to an auditorium or hall to listen to a lecture, you may have noticed that in
some places the sound seems distorted and muffled, while in other halls it is crisp and sounds like
you are in the front row. This has to do with the acoustical design of the hall.
Sound coming from the people on the stage and from the placement of the various loudspeakers
spreads throughout the auditorium. Some of the sound reflects off of the hard surfaces of the walls
and the ceiling. In a large hall, this can result and in an effect call reverberation, where you hear a
slight echo that can distort the original sound. This can also result in dead spots in the hall or
auditorium, where the sound can hardly be heard, as well and as other areas where the sound
seems too loud.
Good auditoriums are designed to eliminate unwanted reflections and echoes and to optimize the
quality of the sound heard by the audience. This is done by engineering the shape of the
auditorium and the walls, as well as to including sound absorbing materials in areas that may cause
echoes.
Outside noises
Outside noises mainly concern your living environment, but they can also be large, noisy
equipment outside a public building. Using walls that can prevent sounds from entering the
building or hall is the most common method of suppressing outside noises.
The use of plywood flats or heavily painted and back-painted canvas flats is advantageous for the
ceiling, side and rear walls. Unfortunately, noise-insulating walls are not that effective.
91
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
3.0.10SIGHTLINES
The focus of a theatre is always the stage, whether it is located centrally or at an end. To achieve a
good auditorium design, each seated person must have a clear view of the stage, projection screen
and other visual aids, which may be the focus. The design of the space to ensure it functions
involves the adjustment of a number of variables but not all of them are within the designer‘s
power to control.
The usually accepted maximum is 20m from the geometrical center. An open stage or from the
setting line of a proscenium stage, for lectures, music etc, in which facial expression are less
important, the distance can be increased up to 30m (Lawson, F. R. 1981).
In designing auditoriums, there is a variable, which is beyond the designer, which is man. The
variable within the influence of regulation of the designer has to do with the design of the sitting
layout.
The maximum vertical angle of elevation from nearest seats to avoid discomfort is 30 0, and should
not exceed 350.
Fig 3.61; Sectional view of Auditorium
Source; Neufert, E. (2000). Pg 315
92
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
a. Anthropometrics
In the past dimensions were based on the human body, and man‘s daily activities. Architectural
design remains largely about man and his spatial needs. The key dimensions upon which sightlines
calculations depend are the height of the eye above the ground in a sitting position and the height
of the top of the head above the eyes. Through mathematical calculations, dimensions that lie
within certain limit can be determined for a particular set of people. Considering the fact that the
facility would be available for users from every way in the world, limits within approved
international standard would be used.
b. Seat Spacing and Chair Design.
The designer‘s target is to provide comfort and ease of circulation. In all design, because of the
likely multi-purpose use of the auditorium, compromises would have to be made within the
standards set by regulatory bodies. For instance the chairs should be comfortable for the user to
look up in cases where a projector screen is in use during presentation sessions, or it‘s being used
for a cinema; and when the user looks down at the focus on stage. The choice of furniture here,
aids clear view. The following Plates show the relationship between the anthropometrics and
sitting layout design in order to achieve good sightlines in auditorium design.
C Stage
For the purposes of this project, it is pertinent that the stage type would be considered in order to
have a good design for the performing Arts theatre. Its size, shape, arrangement, and equipment
must therefore logically develop from the nature from the nature of the performance.
Requirements planned for the stage depend on the performances planned for the building and the
resulting operational, visual, and acoustical criteria associated with each performance type.
Virtually any stage consists of two parts; the performing area and the working areas. The former is
that part of the stage which is typically visible to the delegates and where the performer presents
his or her activity so as to be seen and heard by the delegates.
The backstage which comprises of a wide variety of dressing rooms, work rooms, and storage
spaces needed to support what happens in the stage are provided.
93
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
There are three main types of stage forms which include:

Proscenium stage

Open stage

Arena stage
Proscenium Stage
In this type of stage the audience usually focuses in one direction toward the stage. This has been
the conventional arrangement of the twentieth-century theatres in the United States. The
proscenium stage is a direct descendent of the horseshoe opera house that originated in the
renaissance. It affords the maximum confrontation of performers and audience and is best for
lecturers, concert singers, recitation and dramatic presentation. It establishes a limited orientation
of performers to audience (Fig 3.7).
Fig 3.7: Proscenium stage
Source:
(De Chiara, 2001)
94
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Advantages of having such kind of stage are; it creates a limited, unified, fixed frame for the
pictorial composition of performances, permits the director and designer to relate performers to
scenery, secure in the knowledge that the whole audience will perceive the relationships in the
same way; it is the best arrangement for presenting to an audience a dramatic action of conflict or
opposition of forces because the line of action of the opposition or conflict is across the line of
vision of the audience and hence is maximally perceptible. It is the form most conducive to the
production of total uniform effect; depth in performance can be exploited. The audience is being in
one compact group within a narrow horizontal angle while the performers can relate their actions
to the whole audience simultaneously.
Its disadvantages are: the proscenium form can sometimes fail to produce an intimate theatre
space, since the audience and the actors are each in separate interior rooms although connected.
Stage house wastes acoustic energy and this stage form costs greatest for a given size of audience.
Only very few patrons have the privilege of being seated near the proscenium opening to
appreciate the performance fully. It is limited in seating capacity because the principal direction of
expansion is away from the performance; the limit of good sight becomes the limit of expansion.
Expansion laterally tends to destroy total uniform effect by making occupants of the side seats
view the performance from widely divergent angles and thus see the stage in non significant
relationship.
Open Thrust Stage
In this type of arrangement audience or conferees partially surrounds the stage. It descended from
Greek, Roman, Renaissance, and Elizabethan theatres. The open thrust stage projects or pierces
into the audience with the audience partly surrounding the performance area i.e. truly surrounding
the stage on three sides.
This is said to produce a unity of experience between performers and audience, though the authors
believe that the essential dichotomy of function between performers and audience persists
regardless of spatial relationship and that attempts to resolve this dichotomy are futile, fallacious,
and irrelevant (Fig 3.8).
95
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig 3.8: Open Thrust Stage. Source: (De Chiara, 2001)
Advantages
a.
There is better intimacy between the audience and performer.
b.
It can seat a large number of people compared to the proscenium stage.
c.
It places more conferees or audience closer to the performance than does the
proscenium arrangement and in this way contributes to good sight.
Disadvantages
a. It places a burden of diffused orientation upon directors and performers and makes impossible
the achievement of total uniform effect.
b. It contains inherent difficulties in the entrance difficulties in the entrance and exit of stage
performers.
96
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
C.There is difficulty in satisfying large audience since in addition to the problem of
impressionable view, sound diminishing in remote area might necessitate the employment of
sound boosters and reinforcement equipment which definitely reduce the life in the performance.
Arena Stage
In this type of arena stage audience or conferees surrounds the stage. It variously called, band box,
theatre-in-the-round, circle theatre and deriving certainly from circus, ancient amphitheatre (Fig
3.9).
This arrangement seats the largest audience or conferees within the shortest distance from the
stage. Affiliation between the viewers and performer is maximal and economy is achieved by the
effective limitation of scenery-there can be no scenery or properties that the audience cannot see
over, under, or through.
The disadvantages of having such kind of stage are: Due to the fact that the audience is seated
round the acting area, it is unavoidable that viewpoints will be maximally different, and it becomes
impossible for directors and actors to compose the performance so as to produce a uniform effect.
The condition of one actor blocking audience vision and use of scenery is heavily restricted.
Fig 3.9: Arena stage. Source: (De Chiara, 2001)
97
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
3.0.11PARKING
Individuals with either public or private transport need a parking space from where they alight to
move into the pedestrian walking space. The parking area is aimed at serving both the regular
users, tourists, performing group or groups of individuals and other guests. The general policy is to
harmonize the entry of cars in order to reduce noise pollution and traffic congestion as well as
hazardous and environmentally destructive system of car parks and high costs of extended asphalt
roads and drainage.
Generally, below is the principle of providing parking spaces:
1. For parking facilities of less than 50 cars, at least one accessible parking space shall be provided.
2. For parking facilities of a maximum number of 400 spaces, accessible parking spaces shall at least
be provided in the ratio of 1:50 (one accessible space for every 50 spaces).
3. For parking facilities of more than 400 spaces, at least 8 accessible parking spaces shall be
provided plus 1 space for each additional increment of 100 cars over 400.
4. For outdoor parking, accessible parking spaces shall be located not more than 50m from accessible
building entrances.
5. For indoor parking, accessible parking spaces shall be located right next to accessible elevators, or
as close as possible to exits.
6. The drop-off area would be at least be 3.60 m wide and incorporate an aisle 1.20 m wide to allow
for manoeuvring. The length would accommodate at least two cars.
7. Appropriate curb ramps would be provided to facilitate circulation over paved surfaces.
8. Where no curb exists to mark the separation between pedestrian and vehicle zones, the installation
of a cue is necessary to guide sightless pedestrians:
9. A protected shelter or canopy with seating facilities is a recommended design feature at passenger
loading zones.
98
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
10. Signs would be installed to identify a drop-off zone and prevent its misuse as a parking space (fig.
3.10)
11. Accessible parking areas would be marked by the international symbol of accessibility (fig. 3.11)
Fig 3.10: Drop-off areas
fig. 3.11: signs
The surface of a parking facility would be uniform and smooth.
Entry Control and Vehicular Access
If a perimeter barrier is employed, it will be necessary to provide points of access through the
perimeter for building users (i.e., staff, visitors, and service providers). An entry control point or
guard building serves well as the designated point of entry for site access. It provides a point for
implementation of desired/required levels of screening and access control. The objective of the
entry control point is to prevent unauthorized access while maximizing the rate of authorized
access by foot or vehicle. These measures are not required for all sites and buildings; they are only
required for those considered at high risk.
Location selection for vehicular access and entry control for a building starts with an evaluation of
the anticipated demand for access to the controlled site. An analysis of traffic origin and
destination, and an analysis of the capability of the surrounding connecting road network,
including its capacity to handle additional traffic, should then be performed. Expansion capacity
should also be considered. The analysis should be coordinated with the state and local departments
of transportation.
The existing terrain can have a significant impact on the suitability of a potential entry control
point site. Flat terrain with no thick vegetation is generally preferred. A gentle rise in elevation up
to the entry control guard building allows for a clear view of arriving vehicles. Consider how
99
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
existing natural features such as bodies of water or dense tree stands may enhance perimeter
security and vehicle containment. Entry control spatial requirements vary, depending on the type,
the traffic demand, and the necessary security measures.
Figure 3.12 combined multi-user gates. Source: Defensible Space by Newman (2000)
In the centre for art and culture, more than one type of entry may be required to accommodate the
three basic types of traffic (site personnel, visitors, and commercial traffic). Active perimeter
entrances should be designated so that security personnel can maintain full control without
creating unnecessary delays in traffic. This could be accomplished with a sufficient number of
entrances to accommodate the peak flow of pedestrian and vehicular traffic, and adequate lighting
for rapid and efficient inspection. Some entrances may be closed during non-peak periods, and
should be securely locked, illuminated during hours of darkness, and inspected periodically.
Additionally, warning signs should be used to warn drivers when gates are closed. Doors and
windows on buildings that form a part of the perimeter should be locked, lighted, and inspected
regularly.
100
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
The following measures should be considered in the design of entry control points:

Design entry roads to sites and to individual buildings so that they do not provide direct or
straight-line vehicular access to high-risk buildings. Route major corridors away from
concentrations of high-risk buildings.

Design access points at an angle to oncoming streets so that it is difficult for a vehicle to
gain enough speed to break through the stations.

Minimize the number of access roads and entrances into a building or site.

Designate entry to the site for commercial, service, and delivery vehicles, preferably away
from high-risk buildings whenever possible.

Design the entry control point and guard building so that the authorization of approaching
vehicles and occupants can be adequately assessed, and the safety of both gate guards and
approaching vehicles can be maintained during periods of peak volume.

Approach to the site should be designed to accommodate peak traffic demand without
impeding traffic flow in the surrounding road network.

Provide pull-over lanes at site entry gates to check suspect vehicles. When necessary,
provide visitor/site personnel inspection area to check vehicles prior to allowing access to a
site or building.

Design active vehicle crash barriers (e.g., road alignment, retractable bollards, swing gates,
or speed bumps) as may be required to control vehicle speed and slow incoming vehicles to
give entry control personnel adequate time to respond to unauthorized activities.

Design the inspection area so that it is not visible to the public, when necessary. Place
appropriate landscape plantings to accomplish screening.

Consider current and future inspection technologies (e.g., above vehicle and under vehicle
surveillance systems, ion scanning, and x-ray equipment).

Provide inspection bays that can be enclosed to protect inspection equipment in the event
of bad weather.

Design inspection areas those are large enough to accommodate a minimum of one vehicle
and a pull-out lane. They should also be covered and capable of accommodating the
inspection of the undercarriage plus overhead inspection equipment.

If space is available; provide traffic queuing for vehicles needing authorization.
101
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE

Consider providing a walkway and turnstile for pedestrians and a dedicated bicycle lane.

If possible, provide a gatehouse for the workstations and communications equipment of the
security personnel. It may also serve as a refuge in the event of an attack.

Provide some measure of protection against hostile activity if ID checking is required
between the traffic lanes.

For high security buildings provide a final denial barrier to stop unauthorized vehicles from
entering the site. Most individuals who may attempt to enter without authorization are lost,
confused, or inattentive.
3.0.12THE DISABLED
The category of people classified as disabled are those who have physical impairments resulting in
the inability to walk and as such the confinement to a wheel chair or other aids. In the design of
such a facility, provision must be made for such people to have easy access into the facility and
move round making use of the entire facility as much as possible like others.
Provision would need to be made for ramps as an alternative to stairs where they occur. Special
spaces in the parking lot, which are closer to the main entrance lobby, should also be reserved for
disabled persons who may come in vehicles.
In designing with consideration for disabled persons, the following principles should be enacted:
Accessible parking spaces close to the entrances should be available for the handicapped, there
should be accessible route for the handicapped throughout the complex, there should be accessible
front entrance ramp facilities, there should be no protrusions and obstacles in the passageways that
are likely to be used by the visually handicapped, elderly and the non-ambulatory.
The seating layout in auditorium depends mainly on the format- the relationship between audience
or delegates and performance and the visual and aural limitations associated with a particular type
of production as well as the number of levels and sightlines. Depending to a large extent on the
shape of the room and the position of the aisles or gangways, the rows of seats may be in parallel
lines or with the side rows set at an angle (between 180 and 135º) to those in the centre. In other
cases, the rows of seats may be set to a curved plan so that each seat broadly faces the centre of the
102
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
stage. Seats of varying widths may be deliberately introduced to create staggering of seating
positions from one row to the next, in order to improve sightlines. . Two main systems of seat
spacing are used:
•
Traditional spacing with seats separated into blocks by aisles to limit the number of seats
per row (Fig 3.13). With traditional seating the number in a row is limited to twenty-two if there
are gangways at both ends of the row, and eleven if a gangway is on one side only. In following
these guidelines, the seating, other than in the smallest rectangular auditoria, is divided into blocks
by the gang way. For traditional seating the minimum is 300mm and this dimension increases with
the number of seats in a row.
•
Continental seats which are more widely spaced and arranged in continuous (usually
curved) rows, with the seat ways extending to side aisles from which there are numerous exit
doors leading to a fire-separated passage or foyer (Fig 3.14). Continental seating refers to rows of
seats with more than twenty-two seats extending to side gateways and more exit than traditional
seating. Continental seating is more appropriate with the proscenium format to achieve side wall to
side wall rows of seats. With formats where the audience surrounds the platform it is less
applicable and gangways within the seating become inevitable.
Continental seating is more efficient in providing a higher capacity and is more adaptable to
different auditorium configurations. For continental seating the clearway is to be not less than
400mm and not more than 500mm.legislation also dictates the minimum row to row dimension at
760mm: this is usually not adequate and the minimum should be 850mm for traditional seating.
103
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig 3.13: Traditional Seating. Source: (Lawson, 1981)
Fig 3.14: continental seating. Source: (Lawson, 1981)
104
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
The Working Dimensions of an Auditorium
1. Seat width, with or without arms; the minimum dimension with arms is 500mm and without arms,
450mm as stipulated by legislation. For seats with arms a width of 525mm may be regarded as a
minimum to offer reasonable comfort.
2. Seat height and inclination: height 430mm - 450mm and angle to horizontal of 7-90.
3. Back height and inclination: height of 800-850mm above floor level (the height may be increased
for acoustic reasons), with a back angle of 15-200 to the vertical.
4. Seat depth: 600mm-720mm for seat and back depth reduce to 425mm-500mm when the seat it
tipped. The seat depth varies and depends on the thickness of upholstery and backing and whether
the rear of the seat contains the air-conditioning. For a modest seat with arms, the dimensions can
be as low as 520mm deep and 340mm when the seat is tipped.
Spacing is conditioned by the distance between the leading edge of the seat and the rear of the
back of the seat in front (Fig 4.22).
Fig 3.15: a) row to row dimension and clearway with fixed seating. b) Row to row dimension and
clearway with tipped –up seating.
Source;
(Adler, 1999)
Gangways
The width of gangways within seating layouts at each level within an auditorium is determined by
their role as escape routes and the number of seats served. The minimum width is 1100mm.
105
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Gangways can be ramped up to a ratio of 1.10 and 1.12 if used by persons in wheelchairs. Steps
should have a consistent tread and riser in each section of the gangway; the row to row spacing
and row rise should be compatible with a convenient ratio of tread to riser.
Seating geometry
Seating is usually laid out in straight or curved rows focused toward the stage. Further forms are
the angled row, the straight row with curved change of direction. Curved rows are slightly more
efficient in terms of numbers within a given area but may increase construction.
Seating density
Seats with arms can occupy an area as small as 500mm wide, and less with seats without arms,
with a row to row dimension of 760mm, but can be as large as 750mm wide by 1400mm. this is a
variation from 0.38m2 to 1.05m2 (Fig 3.16, 3.17 and 3.18).
Fig 3.16: Seat density, from 0.38m2 to 1.05m2 per person
Source: (Adler, 1999)
106
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig 3.17: Auditorium seating Source: (Adler, 1999)
Fig 3.18: seat density, from 0.34m2 to 1.09m2 per person
Source: (Adler, 1999)
107
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Table 4.1 shows the dimensions of auditorium seats
DIMENSION
DESCRIPTION
MIN
M
DRAWN
A
AS
X
A
Overall seat depth
600mm
720mm
B
Tipped seat depth
425
C
Seatway (unobstructed
305
400
760
850
500
650mm
450
vertical space between
rows.
D
Back to back seat
Spacing
E
Seat width for seats
500
750
525
with arms seat
Seat width for seats
450
without arms
F
Arm rest width
50
50
G
Seat height
430
H
Armrest height
600
I
Seatback height
800
J
Seat inclination from
70
90
70
150
200
150
450
440
600
850
800
horizontal
K
Back inclination from
vertical
Table 3.3: Dimension of auditorium seats. Source: (Adler, 1999)
Wheelchair consideration
Regulations require a minimum of six places for wheelchair users, or 1/100th of the audience
capacity, whichever if the greater. Their location as discrete areas can be at the rear, front, side or
108
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
within the seating. Wheelchairs can be centrally positioned by forming a bay off a cross-gangway
(Fig 3.19 and 3.20).
A wheelchair user should be able to sit with a party of friends not in wheelchairs. Sightlines from
the wheelchair should be checked, as should the sightlines of those audience members behind.
Some wheelchair users can transfer into auditorium seats.
Fig 3.19: Designated wheelchair area, required dimensions
Source: (Adler, 1999)
Fig 3.20: Plan of a box designed for a wheelchair plus loose chairs
Source: (Adler, 1999)
Space Requirements
109
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
3.0.8 SOLAR RADIATION
Most auditoria must be sheathed against intense solar radiation. In this case, the reduction of solar
radiation penetration is a necessary requirement for integrated and balanced environmental
control. Direct radiation on building surfaces will depend on:

the latitude and altitude of the site

The orientation of the building and inclination of the surfaces.

The date and time and the prevailing conditions of weather and pollution.
Transmission of solar heat through building fabric depends on time of exposure, the absorptive of
the surface, the thermal capacity of the structure and its thermal transmittance value.
Direct sunlight does the following:

Provides strong illumination that enhances details, textures, shape, and colour.

Gives a dynamic vitality to a space through its daily variation. This is especially beneficial in
relieving institutional monotony.

Provides a visual an emotional link to the outdoors
Direct sunlight may be more appropriate in circulation areas and transition areas. Possible methods
of reducing the effects of solar radiation through windows in the centre include;

Recessing the windows to reduce the intensity of solar radiation penetrating the interior spaces.

Provision of venetian blinds, awnings or vertically moving translucent screens e.g. between dual
panes of glass.

Orientation of the building in such a way that the adverse effects of solar radiation is minimised.

Use of tinted windows or reflective glass with lower transmission.

Use of roof shading and projections.
110
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE

The use of shading devices namely;
Vertical devices like columns, fins and rotating louvers, are very useful against the low sun on the
east and west facades. Horizontal devices like balconies, projecting floor slabs and horizontal
panels are most effective against a high sun normally used on the north or south sides.
111
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
REFERENCES

Adler, D. (1999). Metric Handbook Planning and Design Data. London:
Architectural Press.

Crowder, M. (1973). The Story of Nigeria. London: Faber and Faber, p 243,
282.

David Alder. 2nd edition (1999) Metric handbook planning and design Data. (pg 20)
London: Architectural press.

De Chiara, J. &. (2001). Time-Saver Standards for Building Types (4th
edition). New York: Mc Graw Hill Company.

Joseph de Chiara(ed) &Michael J.Crosbie (ed). (2001). Time-Saver Standards for Building
Type (4TH Edtion) ( pg 298-306). Mc Graw-Hill Company.

Lawson, F. (1981). Conference, Convention and Exhibition Facilities- A
Handbook of Planning, Design and Management. London: Architectural Press.

Levin, M. (1983). The Modern Museum. Michigan: Faber & Faber Ltd.

Neufert, E. &. (2001). Neufert Architect’s Data (2nd & 3rd edition.). london:
Blackwell Publishing Company.

Neufert, E (2000). Neufert Architects Data. (pg 315) .Blackwell Science Ltd. Oxford.

wikipedia
112
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
CHAPTER FOUR
CASE STUDIES
113
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
CHAPTER FOUR
4.0 CASE STUDIES
Critical studies of some existing building structures are intricately needed to understand the true
meaning of both symbolism and aesthetics in its purest form. The essence is to find out how these
spaces perform their function together with the maintenance of symbolism and aesthetics, and with
what degree of success have they made in connection to historical, cultural, social and
technological frameworks.
4.0.1FOREIGN CASE STUDIES
4.0.1.1 CASE STUDY 1: THE SIDNEY OPERA HOUSE, AUSTRALIA
This is a magnificent beauty of a structure that is built right there in Sidney Australia by Jørn
Utzon. It has a concert hall (seating 2,678), an opera house i.e. a proscenium theatre (seating
1,507), and drama theatre (seating 544) the Playhouse, an end-stage theatre with 398 seats, the
Studio which is a flexible space with a maximum capacity of 400 people, the Utzon Room i.e. a
small multi-purpose venue, seating up to 210 and the Forecourt, a flexible open-air venue with a
wide range of configuration options. The Opera House is an extraordinary building set in a
stunning harbour. Since its inception it has captured the imagination of people the world over and
has become a cultural symbol not only of the city in which it stands but of the Australian nation. It
is an outstanding human creation, an influential masterpiece of architecture that has unified
landscape and architecture in one monument.
The Sidney opera house is a multi-venue performing arts centre.
Concept
The competition for the design of the opera house generated enormous interest in Australia and
overseas: nine hundred and thirty-three architects registered for it of which only two hundred and
thirty-three (mostly from overseas) submitted a design on a strictly anonymous basis. The Sydney
Opera House is a masterpiece of late modern architecture and an iconic building of the 20th
century. It is admired internationally and treasured by the people of Australia. The massive
concrete sculptural shells that form the Sydney Opera House‘s roof appear like billowing sails
filled by the sea winds with the sunlight and cloud shadows playing across their shining white
surfaces. As the architect envisaged, “it is like a Gothic cathedral that people will never tire of
114
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
and never be finished with” (Utzon, The Sydney Opera House, 1965). The Sydney Opera House is
unique as a great building of the world that functions as a world-class performing arts centre, a
great urban sculpture and a public venue for community activities and tourism. This fabulous
building has become a symbol of its city and the Australian nation.
“The Sydney Opera House is not a simple entity… but alive with citizens and urbanity” (Domicelj,
2005)
The Sydney Opera House does not operate solely as a venue for opera, but as a multi-purpose
venue that hosts a wide range of performing arts and community activities. These include classical
and contemporary music, ballet, opera, drama and dance, events for children, outdoor activities
and functions of all kinds.
It is used as a venue by a wide range of organizations including performing arts companies,
commercial promoters, schools, community groups, corporations, individuals and government
agencies.
Plate 4.0: The Sydney Opera House, Australia
Source: www.clarkvision.com
.
115
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Description
The opera house is undoubtedly a modern symbolic design with a series of large precast concrete
shells, each composed of sections of a sphere of 75.2 metres in radius, forming the roofs of the
structure, set on a monumental podium. The building covers 1.8 hectares of land and is 183metres
long and 120 metres wide at its widest point. it is supported on 588 concrete piers sunk as much as
25 metres below sea level. The vaulted roof shells with their glistening white tiled skin set amidst
the grand waterscape setting of Sydney Harbour are an exceptional architectural element. They
were originally conceived as ―single-layer, rib-reinforced parabolic shells‖ but they had to be
refined during the design, engineering and construction process. The final shape of the shells was
derived from the surface of a single imagined sphere, some seventy-five metres in diameter. This
geometry gives the building great coherence as well as allowing its construction to benefit from
the economies of prefabrication.
Constructed ingeniously, each shell is composed of precast rib segments radiating from a concrete
pedestal and rising to a ridge beam. The ribs of the shells are covered with chevron-shaped,
precast concrete tile lids– the shallow dishes clad with ceramic tiles. The main areas of the shells
are covered in white glossy tiles with matt tiles edging each segment. This creates a beautiful and
ever-changing effect so that the building shines without creating a mirror effect. The tiles change
colour according to the light and the perspective and can be anything from salmon pink, ochre, the
palest of violets and cream or ghostly white. The white glazed shells draw attention to their
identity as a freestanding sculpture.
Plate 4.1 an entrance into Sydney Opera House, Australia (Sydney Opera House, 2010)
The two main shell structures cover the two main performance venues, known as the Concert Hall
and Opera Theatre. The third set of shells that overlooks Sydney Cove was designed specially to
116
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
house a restaurant. Utzon wanted the walls to be expressed as a hanging curtain, a kind of glass
waterfall that swings out as it descends to form a canopy over the lounge terraces and foyer
entrances. Indeed, the north terraces are really great verandas with a glass canopy cover
overlooking the harbour.
The topaz glazed infill between the shells and the podium was built as a continuous laminated
glass surface with facetted folds tied to a structure of steel mullions. A special feature is the
canting out of the lowest sheets, which allows views out without reflections.
The Floor plans
Fig 4.0: Site plan
Source: Sydney Opera House Trust
117
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig 4.1 Ground floor plan
Source: Sydney Opera House Trust
Fig 4.2: First floor plan
Source: Sydney Opera House Trust
118
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig. 4.3:North Elevation
Source: Sydney Opera House Trust
Fig. 4.4:South Elevation
Source: Sydney Opera House Trust
119
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig. 4.5: East Elevation
Source: Sydney Opera House Trust
Fig. 4.6: West Elevation Source: Sydney Opera House Trust
120
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Plate 4.2: Perspective at Daytime. Source: www.berkshirereview.net
Plate 4.3: Interior Perspective of one of the Concert Halls. Source: www.berkshirereview.net
121
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
The structure effectively carries out its major task of transforming “Sydney into a new cultural
metropolis” and the “People‟s Palace”. In doing so it made use of prefabricated materials due to
the high level of precision required in its construction. This necessitated very specialized labour
and equipment which had to be imported, resulting in escalating costs. The Sydney Opera House
took sixteen years to build at an estimated cost of a hundred and two ($102) million. This was six
years longer than scheduled and ten times more than its original estimated cost. Regardless of this,
an Australian member of parliament praises it “as the first and still unrivalled modern
„blockbuster building‟. It has given Sydney and Australia an unrivalled and instantly recognisable
emblem - the greatest public-relations building since the pyramids.
Fig 4.7: Floor Plan, Sydney Opera House, Australia (Sydney Opera House, 2010)
122
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
4.0.1.2CASE STUDY 2:SCOTTISH EXHIBITION AND CONFERENCE CENTER
Plate 4.4: Perspective view Source: www.secc.co.uk
•
Architect: It was designed by Norman Foster.
•
Located: The centre is located at Queen Dock Glasgow, Scotland.
•
Construction: It was built in 1984 and stands as the largest exhibition area in Scotland.
•
The auditorium seating capacity is measuring up to 3000 people.
CONSTRUCTION

The auditorium is built with pre-cast and bonded concrete providing anchorage for several curved
tabular steel trusses, overlaid by parallelograms of profiled aluminum.

The entrance hall is welcomed by a tall glass screen along with eight overlapping aluminum
claddings.

The cylinder has a diameter of 38
123
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig 4.8: Ground floor plan
Source: www.secc.co.uk
Fig 4.9: plan shown indicates the standard seating layout.
Source: www.secc.co.uk
124
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig 4.10: plan shown indicates the standard seating layout.
Source: www.secc.co.uk
Fig4.11: section
Source: www.secc.co.uk
125
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig 4.12: site plan
Source: www.secc.co.uk
Plate 4.5: Interior view
Source: www.secc.co.uk
126
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
MERITS
•
The staff entrance is designed separately from the public entrance.
•
The building has a striking and magnificent architectural character.
•
The structure is flanked by beautiful landscaping.
•
Its large entrance foyer has a dual function, as it also serves as exhibition area.
•
The design considerations for the building include the disabled.
DEMERITS
•
Considering the expected traffic and crowd behavior during traffic congestion, the two entrances
are grossly insufficient.
•
No consideration was given for natural lighting and ventilation
4.0.1.3 CASE STUDY 3: THE EASTMAN THEATRE, NEW YORK
The theatre was established by George Eastman and opened on September 4, 1922, as a centre for
music, dance, and silent film, with orchestral and organ accompaniment. The 3,358-seat theatre is
the primary concert hall for the Eastman School's larger ensembles, including its orchestras, wind
ensembles, jazz ensembles, and chorale.
The theatre is the principal performance venue for the Rochester Philharmonic Orchestra, and the
Eastman Opera Theatre presents fully staged operatic productions each spring. A $5 million
renovation of the theatre building was completed in October 2004. The Eastman Kodak company
donated $10 million for a subsequent renovation that was completed in October 2009; the building's
concert hall was named "Kodak Hall", in recognition of the donation. Location of the theatre is
Rochester, New York, designed and completed by Architects Gordon and Kaebler with Mckim,
Mead and White. Its renovation however was done by Architects Chaintreuil, Jensen and Stark.
The theatre was designed for music, dancing performances, silent film with orchestral and organ
accompaniment.
127
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Plate 4.6: Façade from Gibbs Street.
Fig. 4.13: Seating chart, Eastman (Kodak) theatre.
128
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig. 4.14: Seating chart (mezzanine floor), Eastman (Kodak) theatre.
Description:
For decades, Eastman theatre has served as the community‘s preeminent performance venue, a
magnificent treasure for Rochester, and a hub for cultural life year round. More than 300,000
members of the Rochester community pass through its doors each year. George Eastman‘s cultural
legacy on music is profound.
Eastman theatre has more than fulfilled the promise of the inscription on its facade: ―for the
enrichment of community life.‖ The magnificent 3,094-seat theatre was built as a centre for music,
dance, and silent films. Today it is the primary concert hall for the Eastman‘s schools larger
ensembles, including its orchestras, wind and jazz ensembles, choral groups, and fully staged
operatic productions.
The most visible and dramatic improvement to date is a striking, custom shell designed to enhance
acoustics and complement the aesthetics of the hall. Changes to the stage included dramatically
129
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
improved lighting, all new mechanics and hydraulics for the orchestra pit, state-of-the-Art rigging,
and several backstage enhancements. These upgrades were the first step in bringing Eastman
theatre into the 21st Century.
Fig. 4.15: Eastman theatre First Floor Lobby/Recital Hall Level.
Fig. 4.16: Eastman theatre mezzanine level.
130
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig. 4.17: Eastman theatre third floor level: balcony/faculty studio.
Fig. 4.18: Eastman theatre fourth floor level: rehearsal hall.
131
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig. 4.19: Eastman theatre fifth floor level: control room.
MERITS
•
The auditoria have a custom shell designed to enhance acoustics.
•
Its hall has good aesthetics.
•
The structure is flanked by beautiful landscaping.
•
It has good lighting.
DEMERITS
•
Too many space congestions making the design to look cramped
•
The façade is not aesthetic enough to represent an Arts Theatre.
4.0.1.4 CASE STUDY 4: ADELPHI THEATRE IN LONDON
This theatre is a 1500-seat West End theatre, located on the Strand in the City of Westminster. The
present building is the fourth on the site. The theatre has specialized in comedy and musical
theatre, and today it is a receiving house for a variety of productions, including many musicals.
The theatre was Grade II listed for historical preservation on 1 December 1987. The Adelphi
132
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Theatre was designed by Architects John and Jane Scott and owned by the Adelphi Theatre
Company Limited.
History
It was founded in 1806 as the Sans Pareil ("Without Compare"), by merchant John Scott, and his
daughter Jane (1770–1839). Jane was a British theatre manager, performer, and playwright.
Together, they gathered a theatrical company and by 1809 the theatre was licensed for musical
entertainments and pantomime. She wrote more than fifty stage pieces in an array of genres:
melodramas, pantomimes, farces, comic operettas, historical dramas, and adaptations, as well as
translations. Jane Scott retired to Surrey in 1819, marrying John Davies Middleton (1790–1867).
On 18 October 1819, the theatre reopened under its present name, which was adopted from the
Adelphi Buildings opposite (see fig4.20).
Plate 4.7 the entrance to Adelphi Theatre
Design
The Adelphi Theatre is an exceptional example of Art Deco design situated directly on the Strand.
The theatre was restored in 1993 and has been the home to some prolific musicals and plays, most
recently the hit revival of Chicago which played for over 8 years.
Despite the stunning architecture the theatre is notoriously tricky in terms of seating, and so it is
worthwhile investing some time to find the perfect place to sit. Seat prices vary across all levels due
133
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
to obstructions and overhangs, but the best value for money is often hidden away. The theatre is
split over three levels, with the two tiers set firmly back from the stalls. Best seats are towards the
centre of each row, especially for visual musicals that are often shown in the house.
Stalls (646 seats)
The Stalls feel unmistakably vast due to the partial division of the back section. Each row averages
around 34 seats wide with the lowest and highest numbers providing worst value for money. The
seats themselves are moderately comfortable but some have limited leg room particularly closer to
the front.
The Circle begins to overhang the Stalls at row J, where the seats become divided towards the rear
of the section. The overhang only creates a problem for those sitting beyond row P, where the top
of the stage is cut off. This is taken into account within the current pricing structure and gets
gradually worse the further back you go.
Best seats in this section tend to be around the middle, midway back around row G. It is worth
avoiding seats on the extreme sides; choose to go deeper rather than wider to allow a better overall
view of the stage.
Dress Circle (409 seats)
The Dress Circle does feel rather set back from the stage as the overhang occurs towards the rear of
the stalls. The section does not however feel particularly high, so at most times you seem level with
the action. The rake is particularly shallow which can create problems for children or smaller
audience
members
who
are
plagued
by
sitting
behind
larger
heads.
The Upper Circle overhangs the section around row D, and has a significant effect on those seats
towards the rear. Like the Stalls, the section is only divided midway by half a vertical aisle so those
who wish for extra legroom should aim to sit further back. There are no safety rails running the
length of the Dress Circle so the view is not restricted other than the overhang towards the rear.
Because of the curve of the balcony there are a number of restricted seats at the ends of each row
which should be avoided unless discounted, which can vary between productions. These seats are
not directly facing the stage, and alter the view somewhat of the action. Legroom in this section is
particularly poor and is worse towards the front and at the curves.
134
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Upper Circle (445 seats)
The Upper Circle again feels high and set back from some of the action. For larger productions
such as musicals this may not be so much of a problem, but for more intimate plays it is something
worth considering. The rake is once again shallow meaning it can be difficult to see action at the
very front of the stage.
The section is divided into two halves by a horizontal aisle. The front section provides clearest
views towards the centre, about two or three rows back. Seats at the edge suffer from restricted
sightlines due to the angle, but the overall effect is clear throughout.
The rear section of the Upper Circle is particularly disappointing. The seats themselves look
different and are designed in a different formation over the stairwells. A large safety rail restricts
those on the final two rows and should be avoided at all costs (see Fig 4.21).
MERITS
•
It has a unique Architecture from Art Deco
•
The building has a striking and magnificent architectural character.
•
The entrance is quite large to accommodate crowd entering and exiting the building.
DEMERITS
•
The seats are less comfortable with limited leg room.
•
Some sections in the auditorium have restricted view of the stage.
135
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Seating Plan
Fig. 4.21 the seating plan of the Adelphi Theatre
4.0.1.5 CASE STUDY 5: THE MAUI ARTS AND CULTURAL CENTER, HAWAII.
The Maui Arts and cultural centre came alive as a result of cultural festivities in Hawaii, which
have Maui as its centre point. This theatre is a venue for arts education for Hawaiian cultural
programs, music, dance and theatre performances, international & local art exhibitions, movie
screenings and a colourful spectrum of special events, which was built in 1994.
136
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig. 4.22: Site Plan, Maui Arts and Cultural Centre. Source: (MACC, 2009)
137
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Plate 4.8: the Maui Arts and Cultural centre facade.
Fig. 4.23: The stage of Maui Arts and Cultural Center Source: (MACC, 2009)
138
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig.4.24: Floor plan of Maui Arts and Cultural Center. Source: (MACC, 2009)
Fig. 4.25: Dressing room area, MACC Source: (MACC, 2009)
139
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
MERITS
•
The theatre is designed for all forms of Art performance.
•
The theatre has good shape for acoustics.
•
The structure is flanked by beautiful landscaping.
.
DEMERITS
•
The walking distance from the car park to the Theatre is wide.
•
No consideration was given for natural ventilation
4.0.1.6 CASE STUDY 6: ARTSCAPE THEATRE CENTRE, CAPE TOWN
Artscape Theatre Centre (formerly Nico Malan Theatre Center) is the main performing arts centre
in Cape Town, South Africa. It was opened in 1971 and is located on reclaimed land in the
Foreshore area. The complex includes:

Opera House, seating 1,487 with provision for two wheelchairs.

Theatre, seating 540 but more or less depending upon whether the pit is used.

Arena Theatre, seating 140.
The Artscape Theatre Centre was formerly known as the Nico Malan theatre complex, after the
former National Party administrator of the Cape Province, Dr Johannes Nicholas Malan, who
initiated the project. The centre was renamed in March 2001, when the Artscape Company
replaced the former Cape Performing Arts Board (CAPAB).
Plate 4.9: the Artscape Theatre Facade
140
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Description
Artscape is the main performing arts centre in Cape Town, South Africa. It was opened in 1971
and is located on reclaimed land in the Foreshore area.
Auditorium
The auditorium seats 1487 with provision for two wheelchairs. There are 23 rows of seats in the
stalls and 8 rows on the balcony.
The Opera house stage consists of the main stage, rear stage and two side stages. Stage machinery
is controlled from a computerized panel on the first fly gallery. The Proscenium opening is 15.35m
wide and the main stage is 17.1m deep. There are three stage lifts built into the main stage, each
14m wide by 4.1m deep. These lifts function independently or as combined units and are computer
controlled. They can move down 1.5m below, or up 2.7m above stage level. Each lift has six traps
which can open separately or be joined to form one continuous trap. The stage floor is wood
covered and each lift can tilt ten degrees. The rear stage has a wagon that covers the combined area
of the three stage lifts with a double revolve. The wagon can move forward and be sunk via lifts to
provide a turntable facility on main stage. There are three side stage wagons, each measuring the
same dimensions as the stage lifts, which can move sideways onto the stage either individually or
coupled to form one large combined truck, and can be sunk via the lifts to become part of the main
stage.
Orchestra
The orchestra pit consists of three lifts which can operate separately or as a combined unit. When
lowered, the pit can accommodate 75 to 80 musicians. The lifts can be set at three standard levels
namely, orchestra pit level, auditorium floor level and stage level to form an apron or thrust stage.
MERITS
•
The disabled was considered in the design.
•
The building has a fine architectural character.
•
The stage floor is constructed with wood which is good for acoustics.
DEMERIT
•
Consideration given to the disabled is poor.
141
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
4.0.2LOCAL CASE STUDIES
4.0.2.1 CASE STUDY 1: THE NATIONAL ARTS THEATER, LAGOS
The National Arts Theatre Lagos is a magnificent structure of cultural origin that portrays the
Nigerian heritage. Standing widely circular with its edges tapering like a cap (Plate 4.10), this
edifice is located in IGANMU, Lagos, was completed in 1977 by Techno- exports- troy as the
consulting engineers and Regional design office, Verna Bulgaria as the project Architects.
Plate 4.10: Facade of the National Theatre, Lagos. Source: (Author‟s field study, 2012).
The function is to carry a wide range of national and international events such as music, drama and
dance, films, symposia and conventions. It houses:
a. two Cinema halls of 676 capacities,
b. Conference Rooms,
c. Presidential suites,
d. Two Exhibition halls.
142
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
The main entrance is ramped to ease accessibility of people with disabilities. There are about 25
lifts all over the building to aid vertical movement. The walls have tactile surfaces to aid
recognition by people with visual impairments. Finding ones way is however, difficult and
emergency exits do not lead directly out of the building.
Fig. 4.26: Site Plan of the National Theatre, Lagos. Source: (Author’s field study, 2012)
143
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig. 4.27: Level One Floor Plan of the National Theatre, Lagos. Source: (Author‟s field study,
2012)
144
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig 4.28: Level Two floor Plan, National Theatre, Lagos. Source: (Author’s field study, 2012)
145
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig. 4.29: Level Three Floor Plan, National Theatre, Lagos. Source: (Author‟s field study, 2012)
146
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig. 4.30: Section through the National Theatre, Lagos (Author‟s field study, 2012)
MERITS
•
The building has a striking and magnificent architectural character.
•
The structure is flanked by beautiful landscaping.
•
The design considerations for the building included the disabled.
DEMERIT
•
The circular shape is not good for acoustic purposes.
4.0.2.2CASE STUDY 2: CULTURAL CENTER, CALABAR
Tom Sabo with Messer, Notch Consultants Architect and Planners were the project Architects
while Reynolds Construction Company R.C.C. was the structural Engineers that saw to the
construction and completion of this cultural centre, which is located inside calabar heartland.
147
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
The function of this theatre is to provide an avenue for performances such as dance, music, choral
work, drama and film, for both performers and spectators in the state. It contains a 1000- seat
auditorium, a conference hall and an administrative block. Entrance to the complex is well
articulated, approach by car is possible through a lower foyer on one hand or by foot up the grand
steps into the foyer.
Fig. 4.31: Ground Floor Plan, Cultural Center, Calabar. Source: (Author‟s field study, 2012).
148
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig.4.32: First Floor Plan, Cultural Centre Calabar. Source: (Author’s field study, 2012).
149
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig.4.33: Stage Areas, Cultural Centre Calabar. Source: (Author’s field study, 2012).
MERITS
•
The staff entrance is designed separately from the public entrance.
•
Its large entrance foyer has a dual function, as it also serves as exhibition area.
•
The design considerations for the building included the disabled.
150
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
4.0.2.3CASE STUDY 3: ODUDUWA HALL, OAU ILE-IFE, OSUN STATE
The Oduduwa Hall, Obafemi Awolowo University was completed in 1962 to accommodate a
whole range of indoor activities such as
musical concerts, convocation ceremonies and drama. It
has a seating capacity of approximately 1,350 and other facilities such as: Patron amphitheatre
(now enclosed) with 2,500 seats, a conference facility and spaces for Boxing and wrestling.
Plate 4.11: Facade of Oduduwa Hall (Author‟s field study, 2012)
151
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Plate 4.12: lobby of Oduduwa Hall (Author‟s field study, 2012)
Fig.4.34: Site plan, Oduduwa Hall, Ile-Ife (Onyebuenyi, 2004)
152
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig. 4.35: Level One Plan, Oduduwa Hall (Onyebuenyi, 2004)
Fig. 4.36: Level Two Plan, Oduduwa Hall, Ile-Ife (Onyebuenyi, 2004)
153
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
MERITS
•
The staff entrance is designed separately from the public entrance.
•
The building has a striking and magnificent traditional architectural character..
•
It has a raked seating arrangement which is good for visual purposes.
DEMERITS
•
The design considerations for the building include the disabled..
•
No consideration was given for natural lighting and ventilation
154
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
REFERENCE

Australian National Training Authority. (2005). Adaptive and Assistive Technologies in Elearning. Retrieved 30 November, 2005, from

(Author‘s field study, 2012)

Axinn, J., & Stern, M. (2000). Social welfare: A history of the American response to need.
Boston, MA: Allyn & Bacon.

Barton, L. (1996). Integration: Myth or Reality? London: Falmer Press.

Eastman School Renovation Image Gallery. Retrieved Nov. 20, 2010 from
http//:esm.rochester.edu. image_gallery

Goldberg, D. T. (1994). Multiculturalism: A critical reader. Oxford, England:
Blackwell.Guardian
News
and
http://www.guardian.co.uk/stage/

Media.
Retrieved
13
September
2010
from
2010
from
2009/jan/06/dance-candoco Technology.
Lincoln Center. (2010). Retrieved 20 November 2010 from
new.lincolncenter.org/live/index/php/map-of-lincoln-center

Muai Arts and Cultural Center. (2009). Retrieved 5 October 2009 from
http://www.muaiarts.org/castlefloor.html

New
York
State
Theater.
(2010).
Retrieved
13
August
www.gotickets.com/venues/ny/New_York_State_Theater.php

Onyebuenyi, E. A. (2004). A Center for Performing Arts, Abuja. Master‘s
degree Thesis, University of Nigeria, Nsukka.

Sydney Opera House. (2010). Retrieved on 15 November 2010 from
Sydney Opera House Trust

http://www.timber.org.au/NTEP/resources/ozs.pdf

www.clarkvision.com
155
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE

www.reallyuseful.com/theatres/adelphi-theatre

http://www.flexiblelearning.net.au/projects/resources/2005/adaptive
and_assistive_technologies_in_elearning_report.pdf

www.berkshirereview.net

Scottish Exhibition and conference centre. 2010. Online Wikipedia. Retrieved February 26,
2010, from http://en.wikipedia.org./wiki/Scottish_Exhibition_and_conference_centre.
156
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
CHAPTER FIVE
SITE LOCATION AND ANALYSIS
157
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
CHAPTER FIVE
5.0 SITE LOCATION AND ANALYSIS
5.0.1 SITE LOCATION STUDY
Enugu
Enugu is the capital of Enugu State in Nigeria. It is located in the south-eastern area of Nigeria
and is largely populated by members of the Igbo ethnic group. The city has a population of
722,664 according to the 2006 Nigerian census. It was known to be the former headquarters of the
Eastern region. It has a total area of forty four square miles (113km2). The state has its slogan as
the ―coal city state‖ due to its richness in coal mineral.
ENUGU STATE NIGERIA
Fig. 5.0: Map of Nigeria showing Abuja (Microsoft Encarta, 2008)
158
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig 5.1: Map of Enugu state. Source: Microsoft Encarta Map
5.0.1.1 Climate
The rainy season begins in April and lasts until October with annual rainfall varying from
1,500mm to 2,200mm (60 to 80 inches). An average annual temperature above 20 °C (68.0 °F)
creates an annual relative humidity of 75%. With humidity reaching 90% in the rainy season. The
159
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
dry season experiences two months of Harmattan from late December to late February. The hottest
months are between January and March.
Fig.5.2 Nigeria Climate Distribution
Fig. 5.3 Nigeria Weather Distribution
160
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Site orientation
To obtain maximum natural ventilation, the orientation of the building is to be in the South EastNorth West axis. To avoid sun glare and solar radiation, buildings are better oriented so that the
longer side faces the North- South pole while the shorter facade faces the East- West pole. The
building will be oriented in such a way to maximize both natural ventilation and natural lighting.
The use of sun shading devices will be employed where necessary.
Prevailing wind and sun path
The site experiences two prevailing winds, the north east trade winds and south west monsoon
winds. The north east trade winds blows from the Sahara desert in Northern Africa, and is
characterized by the dryness and dust it causes during the dry season. The north east trade wind
brings harmattan winds-cool, dry, dusty, haze laden wind. On the other hand, the south west
monsoon winds blows from the Atlantic Ocean, and is characterized by the wetness it causes
during the rainy season.
The site also experiences sunrays which rises from the east and sets on the west. The intensity of
the solar radiation produced will be controlled and reduced by proper landscaping, good
orientation of the proposed conference centre and use of shading elements on the building.
5.0.1.2 Site location
The choice of the site was informed by the Enugu master plan. The large land mass which is
located just close to one of the prominent markets in Enugu (New market) serves as to be a ―first
port of call‖ for the sighting of a Symbolic Structure that will draw the attention of people moving
in and out of the state. The site is accessed from Enugu/Onitsha expressway and meeting the
famous new market roundabout.
161
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
PROPOSED SITE ALONG NEW
MARKET ROAD
Plate 5.0: Location of the site. Source: (Google Earth, 2012)
AREA OF SITE=36,593.699m2. Source: Author‘s Illustration
5.0.1.3 Access and Circulation
The site is located just beside new market and backed by the NGWO hills with the recent access
point from the Enugu/Onitsha expressway. The main access is on the North going off from the
major road to ease traffic.
162
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig.5.4: Access into the site. Authors sketch
5.0.1.4 Slope of Land
The site slopes from the west where the Ngwo hills is located towards the east with the highest
point being 180m above sea level and the lowest point is 100m above sea level; this shows a
gradient of 10m which allows for proper drainages that help to avoid erosion. Figure 5 shows the
slope of the site.
Plate 5.1: The Site Source: phone by Author (2012)
163
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Fig.5.5: slope of the site. Authors sketch
5.0.1.5 Utilities
Pipe-borne water, good road network, street lights, electricity and communication networks are
available on the site.
5.0.1.6 Views and Vistas
The golf estate, new market, is all visible from the site.
164
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
5.0.1.7 Noise Pollution and Zoning
The site is liable to noise pollution from the major express road (Enugu/Onitsha expressway) as
well as from the motor park that is beside it which can be seen in figure 5.6 and 5.7 below.
Fig.5.6: Noise source. Authors sketch
165
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
Noise zone
Semi noise-zone
Quiet zone
Noise zone
Fig.5.7: Zoning. Authors sketch
HUMIDITY
Enugu records a high humidity and rainfall (about 1,485.2mm, per annum while it varies from
70% and 80%. The relative humidity varies from 40% to 92%. The month of lowest humidity is
January. At such periods, the relative humidity of less than 45% could be recorded.
TOPOGRAPHY
Enugu topography lies between 150 and 300m above sea level on the plains, with hills almost
looking like it is surrounding the metropolis.
SOIL
Enugu soil is characterized by loamy, clay and fine white sands, and lateritic, red to brownish soil,
poorly cemented and with moderate permeability.
166
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
WIND
The two prevailing winds in Enugu are the north east trade winds and south west monsoon winds.
The north east trade winds blows from the Sahara desert in Northern Africa, and is characterized
by the dryness and dust it causes during the dry season. The north east trade wind brings harmattan
winds-cool, dry, dusty, haze laden wind. On the other hand, the south west monsoon winds blows
from the Atlantic Ocean, and is characterized by the wetness it causes during the rainy season.
DEDUCTIONS
•
Orientation must consider wind force
•
Roof pitch must be greater than 25o slope to be able to withstand wind storms
•
Use wind breakers and landscape elements.
SUNSHINE
These generally progresses from morning to break in the afternoon only to fall to zero in the
evening. There are 160 -205 hours of mean sunshine during dry season. The sunshine is usually
highest during this season (dry season). From July –September isolation is lowest. Mid-day sun is
usually intensive and undesirable. Morning and evenings are the most comfortable times. Early
morning sun is good for the health as it gives vitamin D.
DEDUCTION
•
Good landscaping will help softening the atmosphere.
•
Sunshades will help reduce the penetration intense sunlight into the building.
•
Orientation of the building must be properly positioned.
167
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
REFERENCE

Authors on-site Investigation

Nigerian Meteorological Agency(NIMET)

Google earth 2012
168
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
CHAPTER SIX
THE DESIGN
169
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
CHAPTER SIX
6.1 THE DESIGN
Design Philosophy
This design is meant to reflect the solution to sound and noise management in arts theatres and at
the same time reflects on the facades, the peoples cultural heritage with functional and
contemporary background. However the major goal of the proposed performing arts theatre is to
solve the problem of acoustics.
Design Concept
In an attempt to achieving effective acoustic probabilities in performing arts theatre, certain design
advices were studied and adopted, which shall evolve as the concept on which the design is built.
However, concept is a broad principle affecting perception and behavior: a broad abstract idea or a
guiding general principle, e.g. one that determines how a person or culture behaves.
The concept that will form the basis of this design externally will emanate from the use of the
cultural instrument known as ichaka (in inverted form) which is found in the Igbo culture. This
instrument is known for its wide usage in Igbo traditional dances and performances (plate 6.1)
which can help to work from form to function, in order to create an enclosed space where the
principles of acoustics will be applied.
Plate 6.1 Design Concept
170
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
6.2 DESIGN CONTRIBUTION
Considering the developing nature of Enugu state, many major corporations especially those in
telecommunication, insurance, industries and financial services are coming into big time
investment and there is the need to have a performing arts theatre where cultural heritage is
showcased. Therefore, the location of the performing arts theatre in Enugu metropolis will give
room for real time development to that area where it is located.
6.3RECOMMENDATION AND CONCLUSION
In order to ensure proper and good Acoustic design in performing Arts theatre, the following
recommendations are necessary;

There should be a proper integration of acoustical materials into performing arts theatre in
other to achieve efficient acoustics; this is important and crucial in the design and planning.

There should be segregation of circulation flow; the pedestrian and vehicular traffic on site
and in the theatre to avoid conflict of traffic and accident.

Use of raked seats on the floors of the auditoria, and which are of course, of very important
to the proper functioning of the arts theatre
.
In conclusion the research has dealt deeply on acoustic in Arts theatre with particular reference to
its design. Having seen the numerous problems associated with arts theatre, it will need an artistic
and scientific data bank to serve as a base for its design. In order word, for proper acoustics
management and control these items should be considered;

the form and shape,

the volume,

the proper use of a good absorptive materials on walls of the auditorium,

Use of raked seats on the floors of the auditoria, and which are of course, of very important
to the proper functioning of the performing arts theatre. Consequently, the successful
planning of the performing arts theatre involves a well considered choice and strict
application of these deciding principles.
171
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
However, this type of arts theatre will go a long way in creating a state-of-the-art performing
theatre with efficient and effective acoustic flow system which shall be an identity for Enugu as
well as improve the tourism potentials of the state, and in turn generate revenue and employment
for the inhabitants.
172
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
REFERENCE

Adler, D. (1999). Metric Handbook Planning and Design Data. London:
Architectural Press.

Australian National Training Authority. (2005). Adaptive and Assistive Technologies in Elearning. Retrieved 30 November, 2005, from

(Author‘s field study, 2012)

Axinn, J., & Stern, M. (2000). Social welfare: A history of the American response to need.
Boston, MA: Allyn & Bacon.

Bagenal (1931). H. Bagenal and A. Wood, Planning for Good Acoustics. Methuen,
London, 1931.

Barton, L. (1996). Integration: Myth or Reality? London: Falmer Press.

Breton (1989). Gaelle Breton, Theaters. New York, NY: Princeton Architectural

C. Himmel and J. Evans (2002) ―Texas Heart Institute Acoustical Performance Testing
Results”, JEAcoustics,

Cavanaugh (1999), William J., and Joseph A. Wilkes, eds. Architectural Acoustics:
Principles and Practice. New York: John Wiley & Sons.

Cremer (1982). Lothar Cremer and Helmut A. Müller, Principles and Applications of
Room Acoustics, vol. 2. New York, NY: Applied Science Publishers.

Churchill, W. (1924). Address to the Architectural Association at the annual distribution of
prizes. Architectural Association Quarterly, 5:44–46.

Crowder, M. (1973). The Story of Nigeria. London: Faber and Faber, p 243, 282.

David Alder. 2nd edition (1999) Metric handbook planning and design Data. (pg 20)
London: Architectural press.

De Chiara, J. &. (2001). Time-Saver Standards for Building Types (4th edition). New
York: Mc Graw Hill Company.
173
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE

Eastman School
Renovation
Image Gallery.
Retrieved Nov. 20, 2010 from
http//:esm.rochester.edu. image_gallery

Evans, Jack B (1999), ―Acoustical Noise Control Recommendations for Building
Mechanical Systems 904‖, JEAcoustics.

Forsyth (1985). Michael Forsyth, Buildings for Music. Cambridge, MA: MIT Press.

Garnier (1880). C. Garnier, Le nouveau Opéra de Paris, 2 vols. Ducher et Cie, Paris.

Goldberg, D. T. (1994). Multiculturalism: A critical reader. Oxford, England:
Blackwell.Guardian News and Media.

Guillen (1995). Michael Guillen, Five Equations that Changed the World: The Power and
Poetry of Mathematics. Hyperion. ISBM 078 688 1879.

Google earth 2012

Hunt (1964). Frederick V. Hunt, ―Introduction to Dover Edition,‖ Collected Papers on
Acoustics by Wallace Clement Sabine. New York, NY: Dover Publications.

Ingard (1994). K.U. Ingard, Notes on Sound Absorption Technology. ver. 94–2, Kittery
Point, ME: K.U. Ingard.

Izenour (1977). George C. Izenour, Theater Design. New York, NY: McGraw-Hill. The
George C. Izenour Archive at Penn State University.

Joseph de Chiara(ed) &Michael J.Crosbie (ed). (2001). Time-Saver Standards for Building
Type (4TH Edtion) ( pg 298-306). Mc Graw-Hill Company.

Lawson, F. (1981). Conference, Convention and Exhibition Facilities- A Handbook of
Planning, Design and Management. London: Architectural Press.

Levin, M. (1983). The Modern Museum. Michigan: Faber & Faber Ltd.

Lindsay (1966). Bruce Lindsay, ―The Story of Acoustics.‖ Reprinted with permission from
J. Acoust, Acoustical Society of America: Melville, NY.

Lincoln Center. (2010). Retrieved 20 November 2010 from
new.lincolncenter.org/live/index/php/map-of-lincoln-center
174
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE

Marshall (1967). A. Harold Marshall, ―A note on the importance of room cross-section in
concert halls.‖ Journal of Sound and Vibration. 5.

Muai Arts and Cultural Center. (2009). Retrieved 5 October 2009 from
http://www.muaiarts.org/castlefloor.html

New
York
State
Theater.
(2010).
Retrieved
13
August
2010
from
www.gotickets.com/venues/ny/New_York_State_Theater.php

Nigerian Meteorological Agency(NIMET)

Onyebuenyi, E. A. (2004). A Center for Performing Arts, Abuja. Master‘s
degree Thesis, University of Nigeria, Nsukka.

Oxford advanced learners dictionary

Pierce (1983). John R. Pierce, The Science of Musical Sound, Scientific American Books.
Used with permission by W.H. Freeman and Company.

Sabine (1922, 1964). Wallace Clement Sabine, Collected Papers on Acoustics. New York,
NY: Dover Publications, reprinted.

Skudrzyk (1954). Eugen Skudrzyk, Die Grundlagen der Akustik. Wien: Springer-Verlag.

Scottish Exhibition and conference centre. 2010. Online Wikipedia. Retrieved Feb.
http://en.wikipedia.org./wiki/Scottish_Exhibition_and_conference_centre.

Sydney Opera House. (2010). Retrieved on 15 November 2010 from Sydney Opera House
Trust

W.J. Cavanaugh and J.A (1999), Wilkes, Architectural Acoustics, John Wiley & Sons,
New York.

Wilson, C.E. (1989), Noise Control, Harper & Row Publishers, New York.

http://www.timber.org.au/NTEP/resources/ozs.pdf

www.clarkvision.com

www.reallyuseful.com/theatres/adelphi-theatre

www.berkshirereview.net

http://www.flexiblelearning.net.au/projects/resources/2005/adaptive
and_assistive_technologies_in_elearning_report.pdf
175
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
BIBLIOGRAPHY

Beranek (1979) (Original Edition 1962). Leo L. Beranek, Music, Acoustics &
Architecture. Cambridge, MA: Courtesy Leo L. Beranek.

Beranek (1996). Leo Beranek, How They Sound, Concert and Opera Halls, Woodbury,
NY: Acoustical Society of America.

Neufert, E. &. (2001). Neufert Architect‘s Data (2nd & 3rd edition.). london: Blackwell
Publishing Company.

Neufert, E (2000). Neufert Architects Data. (pg 315) .Blackwell Science Ltd. Oxford.
176
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
SITE PLAN
177
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
GROUND FLOOR PLAN
178
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
FIRST FLOOR PLAN
179
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
SECOND FLOOR PLAN
180
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
ROOF PLAN
181
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
SECTIONS
182
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
ELEVATIONS
183
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
ELEVATIONS
184
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)
PERFORMING ARTS THEATRE ENUGU: A STUDY OF ACOUSTICS IN ARTS THEATRE
EXTERIOR PERSPECTIVE
185
ASOGWA CHUKWUMA JACOB (PG/MSC/10/54624)