Download CH14 Sound Use This - Van Buren Public Schools

SOUND
It is composed of waves of
compression and rarefaction in
which the human ear is sensitive
-It simply follow an orderly pattern or
coherence, of motion.
-It can begin either from simple
harmonic motions (SHMs) or from
complicated motions.
-sound waves carry energy.
-sound wave is a longitudinal wave.
-the size of a compression indicates how
much energy the sound wave has.
Sound is produced
when a vibration
causes pressure
variations in the
medium.
B. HUMAN HEARING
sound wave
vibrates ear drum
amplified by
bones
converted to
nerve impulses in
cochlea
Human voice uses
several types of
sound production and
modification of
mechanisms.
The vocal chords located
in the LARYNX (voice
box) in the throat
primarily produces the
sound for singing and for
spoken vowels.
-sounds produced differ
because of the
differences in SHAPE of
the air cavities in the
throat, mouth and nasal
region.
Propagation of sound
Medium
-Material that sound
waves can travel
through.
-It can travel through
solids, liquids and
gases but not through a
vacuum.
Sounds possess the
characteristics
and properties that
are common to all
waves.
Just like all longitudinal
(compression)waves, sound
Waves possess a velocity,
frequency, wavelength,
phase, period, and amplitude.
Sound waves also reflect,
refract, diffract, and interfere.
Properties of
sound waves
II. Properties of Sound
1. PITCH
-highness or lowness of a
sound.
a. FREQUENCY
-number of sound waves
that passes through a point
in a certain amount of time,
such as one second.
-the greater the frequency,
the higher the pitch.
Hertz (Hz)- unit to measure
frequency and pitch
Audio frequency range
-Frequency ranging 20 Hz to 20 000 Hz
-Sounds that human ear can hear is an
example.
INFRASONICS
-Frequency below 20 Hz.
2. LOUDNESS or intensity
-description of how high or
low the sound seems to a
person
-determined mainly by the
amplitude of the sound
wave
a. Decibel (dB)- unit used to
measure sound intensity or
loudness.
LOUDNESS OF SOUND IN DECIBELS
Sound
Loudness (dbs) Hearing
Damage
Average Home
40-50
Loud Music
90-100
After long
exposure
Rock Concert
115-120
Progressive
Jet Engine
120-170
Pain
Threshold of
hearing
-sound of the
quietest sound
that can be
heard under
ideal conditions
is 0 dB.
Threshold of
Pain
- Sound level of
120 dB which
can pain and
damage to the
ears.
The human ear relates
amplitude to
loudness
and
frequency to
pitch.
3. TIMBRE
-tone color or tone quality
-used to distinguished
between two different
sounds that have the same
pitch and loudness
- It helps to identify what
produced the sound
2 Different waveforms
1. Pure tone- simplest wave
form, it has a soft,
pleasant tone quality
and sinusoidal
2. Complex tone- nearly
sinusoidal
A. Speed of Sound
Depends on:
1. Type of medium
-travels better through liquids and
solids and gas
can’t travel through a vacuum.
2. Temperature of medium
-travels faster at higher
temperature.
3. Density
-sound moves well through dense
materials.
4. Elasticity
-sound waves move fast through
elastic materials
B. DOPPLER EFFECT

Doppler Effect
 change
in wave frequency
caused by a moving wave
source
moving toward you pitch sounds higher
moving away from you pitch sounds lower
A. Refraction of sound
-change in direction,
as the wave moves
from one medium to
another
- It bends or refracts
as they move
through air.
Sound waves refract.
B. Reflection of sound
Echo- reflected sound
- it is what you
heard shortly
after the original
C. Diffraction of Sound
- Sound waves bend or
diffract around
corners or barriers
like doors and walls.
D. INTERFERENCE
the result of two or more sound
 waves overlapping

2 types
Constructive interference
-the sound waves arrive at
the same time and phase
Destructive interference
-waves arrive at interval
and are out of phase
* Fact *
D. Resonance
- the inducing
of vibrations of a natural
rate by a vibrating source
having the same frequency
A. Characteristics of musical sounds
Note- basic element of music
1. Pitch- highness or lowness of
the note
2. Intensity- loudness of the note
3. Rhythm- repeating pattern of
beats and it keeps the time to
the music
4. Melody- series of pitches
5. Harmony- three or more notes
played together.
* Fact *
Noise- unwanted sound
and a subtle pollutant
which can threaten the
Health or well being of
an individual.
CLASSIFICATION OF INSTRUMENTS
A. Stringed instruments
- Produce a tone when their strings
vibrated.
B. Wind instruments
-contain a column of air that vibrates when
air is blown to the instrument
C. Percussion instruments
-produce sound when they are struck