06/18/22 Tech I Lighting Unit 1 Sound: Properties and Functions Technical Theatre I
Jan 01, 2016
04/20/23 Tech I Lighting Unit 1
Sound: Properties and Functions
Technical Theatre I
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Introduction to Sound Acoustics is the science that deals
with the production, control, transmission, reception, and effects of sound; the study of sound
The students will learn the properties of sound and its applications in theatre
Understanding sound is essential to sound design
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Properties of Sound (the Science)
Sound is a vibration of a medium
Medium – a material that transmits energy
Speed varies depending on pressure, temperature 1129 ft/sec, 770 mi/hr in air, 4708 ft/sec, 3210 mi/hr in
water 3.17 mi/sec in steel
What we hear is based on perceived vibrations
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Measuring Sound Sound travels in waves
(sound waves), which are transferences of energy via rapid changes in the density of a medium
Sound waves are measured by speed, wavelength, amplitude, and frequency
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Measuring Sound (Wavelength)
Wavelength (λ)– the distance between repeating units of a wave pattern; the distance from one crest to the next repeated crest, or one trough to the next repeated trough
λ of a 10,000Hz sound –> 1.35 inches λ of a 188Hz sound –> 6 feet
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Measuring Sound (Amplitude)
Amplitude – (A) the distance of the crests and/or troughs of a waveform from the neutral line
Amplitude in sound waves is representative of intensity, or Volume (loudness)
Volume is measured in decibels (dB, or deci-Bells), a logarithmic scale <85 dB is considered harmful <95 dB can cause permanent
damage if exposed for prolonged periods
<125 dB can cause instant hearing damage
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Measuring Sound (Frequency) Frequency – (f) the number of
occurrences of a repeated event per unit of time; pitch
Usually measured in occurrences per second, or Hertz (Hz)
Human hearing is usually represented as being “20 to 20,” i.e. 20 Hz to 20,000 Hz (or 20kHz)
Our hearing is typically more like 22 Hz to 18kHz, and continues to decrease as people age
Frequencies (Do you hear what I hear?)
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440 Hz 1000 Hz 1500 Hz 2 kHz 4 kHz 8 kHz 14 kHz
15 kHz 16 kHz 17 kHz 18 kHz 19 kHz 19.5 kHz
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Adding Frequencies
Adding two identical frequencies in the same phase reinforces the sound
Adding two identical frequencies 180° out of phase cancels out the sound
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Adding Frequencies (continued)
Adding two different frequencies results in a different frequency, reinforced in some places & cancelled in others
Timbre and Harmonics
Few sounds are pure tones; most sound is made up of a combination of frequencies and amplitudes
Timbre - /tam’-bər/ a quality given to a sound by its overtones (harmonics)
Harmonic – a frequency that is an integral multiple of the fundamental
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Perception of Sound
Distance – decreases the volume (the Inverse Square Law); air absorbs higher frequencies
Loudness – humans hear 2k-4k Hz best, thus this range is perceived loudest
Masking – one sound obscured by others; lower usually masks higher
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Functions of Sound in Theatre Sound Effects – (FX) used to illustrate
ideas in a play or establish ambience, i.e. radios, explosions, trees rustling in the wind, crickets at night, sounds of machinery in a manufacturing plant
Underscoring – music used to establish or reinforce mood
Live Reinforcement – microphones used to boost the loudness of existing sound(s)
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The Path of Sound Source – can be live or pre-recorded
Microphones, pick-ups, synthesizers Or CD, tape, MD, mp3 or other computer file
type, record, etc. Amplifier – adds power to source signal,
boosts mic, instrument, or line level to speaker level Processor – can affect signals with effects or
ehancements Output – either speaker or recording
device
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Input sources:
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Patch Panel
Synthesizer Computer CD
Crossover
Delay
Compressor
Effects Processor
Equalizer
Mixing Console
Amplifier
Amplifier
Microphone
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Input sources: -Microphones
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Patch Panel
Synthesizer Computer CD
Crossover
Delay
Compressor
Effects Processor
Equalizer
Mixing Console
Amplifier
Amplifier
Microphone
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Input sources: -Microphones
-Synthesizer
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Patch Panel
Synthesizer Computer CD
Crossover
Delay
Compressor
Effects Processor
Equalizer
Mixing Console
Amplifier
Amplifier
Microphone
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Input sources: -Microphones
-Synthesizer
-Computer
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Patch Panel
Synthesizer Computer CD
Crossover
Delay
Compressor
Effects Processor
Equalizer
Mixing Console
Amplifier
Amplifier
Microphone
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Input sources: -Microphones
-Synthesizer
-Computer
-CD
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Patch Panel
Synthesizer Computer CD
Crossover
Delay
Compressor
Effects Processor
Equalizer
Mixing Console
Amplifier
Amplifier
Microphone
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Signal Processing:
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Signal Processing:-Equalizer
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Patch Panel
Synthesizer Computer CD
Crossover
Delay
Compressor
Effects Processor
Equalizer
Mixing Console
Amplifier
Amplifier
Microphone
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Signal Processing:-Equalizer-Effects Processor
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Patch Panel
Synthesizer Computer CD
Crossover
Delay
Compressor
Effects Processor
Equalizer
Mixing Console
Amplifier
Amplifier
Microphone
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Signal Processing:-Equalizer-Effects Processor-Compressor
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Patch Panel
Synthesizer Computer CD
Crossover
Delay
Compressor
Effects Processor
Equalizer
Mixing Console
Amplifier
Amplifier
Microphone
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Signal Processing:-Equalizer-Effects Processor-Compressor-Delay
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Patch Panel
Synthesizer Computer CD
Crossover
Delay
Compressor
Effects Processor
Equalizer
Mixing Console
Amplifier
Amplifier
Microphone
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Signal Processing:-Equalizer-Effects Processor-Compressor-Delay-Crossover
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Patch Panel
Synthesizer Computer CD
Crossover
Delay
Compressor
Effects Processor
Equalizer
Mixing Console
Amplifier
Amplifier
Microphone
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Output Sources:
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Output Sources:-Amplifier
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Patch Panel
Synthesizer Computer CD
Crossover
Delay
Compressor
Effects Processor
Equalizer
Mixing Console
Amplifier
Amplifier
Microphone
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Output Sources:-Amplifier-Loud Speakers
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Patch Panel
Synthesizer Computer CD
Crossover
Delay
Compressor
Effects Processor
Equalizer
Mixing Console
Amplifier
Amplifier
Microphone
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