Download Sound Answer sheet - Fiji National University | E

Fiji National University
College of Humanities and Education
School of Communication & Creative Arts
Department of Film & Television
FINAL EXAMINATION
Sound Recording & Sound Engineering, I Trimester I/2014
Total Marks- 50
Answer Sheet.
Q1 Explain how sound is created? Describe with example.
• ANSWER- What we hear as sound is a series of pressure waves
produced by vibrations. The sound pressure level is generated
by a vibrating body (like Guitar strings, Human vocal chords,
loud speakers).
Q2. What are the properties of a sound wave? Explain briefly the
functions of each property.
 ANSWER- The sound wave properties are: Wavelength
 Amplitude
 Frequancy.
Wavelength :- The distance between any point on a wave and the
equivalent point on the next phase. Literally, the length of the wave.
• Amplitude:- The strength or power of a wave signal. The
"height" of a wave when viewed as a graph.Higher amplitudes
are interpreted as a higher volume.
• Frequency:- The number of times the wavelength occurs in one
second. The faster the sound source vibrates, the higher the
frequency.
Q3. How digital audio is recorded in the camcorder or in a field
recorder.
 Answer: - Microphones convert sound waves (Sound energy)
into electrical energy or voltage. This voltage travels from the
microphone to the amplifier, which increases its strength. The
amplified voltage is sent to analog- to- digital converter(A/D),
A/D converts the voltage into binary numbers. Once we have
the sound converted to digital data, we can then store it in flash
memory, a hard drive, a CD,tape or other medium.
Q 4. What is the difference between analogue and digital sound?
What is the advantage of digital sound? Explain why a digital signal
needs to be converted back to analog for hearing.
•
Answer:- The word analogue sound refers to a sound wave
that is continuously variable and whose size forms a closest
shape of countless points that are related to the reference. For
example an audio wave where the shape of the signal varies
with the amplitude and phase of the vibration produced by an
instrument.
Digatal sound is the numeric representation of analogue sound (
in the form of voltage levels).
Digital signal is easy to store, easy to process, quality is good
and easy to send.
D/A converter converts digital sound and Video back to
analogue form. Since human ear and eyes can only listen and
see analogue signal. Thus for viewing and listening we need to
convert Video& audio signal to analogue signal.
Q 5. Explain dynamic and condenser Microphones. How is a unidirectional microphone different from a omni- directional
microphone and a bi- directional microphone.
 Answer:- Dynamic microphones are rugged and robust. They
don’t require any external power supply to operate. They are
less sensitive than condenser microphone.
 Condenser Microphones produce very high quality of sound and
they are very sensitive. They are very delicate. Unlike Dynamic
microphones condenser microphones need external power
supply to operate.
 A uni-directional microphone can pick up sound only from one
direction. They are ideal for shooting.
 A omini-directional microphone, can pick up sound from all
directions, they are not ideal microphone for shooting. They are
good for location sound recording.
 A bi-directional microphone have a figure of eight pick up
pattern. Can pick up sound only from the front and rear. They
are not ideal microphone for shooting for TV serials or Films.
They come in handy for recording two personse seated across a
table for an interview.
Q6. Define
 Unit of Sound level(Loudness)
 Dynamic range.
 Human hearing range
 What is LF, MF, HF.
Answer.
Loudness is measured in decibels (dB).
The difference in volume between the quietest point and the
loudest point is called DYNAMICRANGE
The human hearing range is in between 20 HZ to 20 KHZ. The
sound above 20KZ can be heard by Dogs and Bats.
Low Frequancy, Mid Frequancy and high frequency.
Q7. Describe the frequency response of a system.
• Frequency response defines how the audio system responses to
the various frequencies of the sound wave. It should be flat.
Which indicates, when it is supplied with a reference input of
equal level over the 20-20000Hz of human hearing, the device
should pass all frequencies equally ( with no frequency being
emphasized or de-emphasized).
Q8. Fill up the blanks
 A sponge like material used over microphones to avoid wind
and other undesirable frequencies is called WINDSHIELD.
 A one to one interview in the studio can be recorded using a BIDIRECTIONAL microphone.
 It is best to use a UNI- DIRECTIONAL microphone for
shooting.
 Power supplied to a microphone through the connecting cable it
self is called PHANTOM POWER SUPPLY.