Development of Technology

Nature of Audio 1 - What is sound?

Q: What is sound? A: Molecules moving in a medium – usually air

Q: What is compression? A: Molecules move tightly together

Q: What is rarefaction? A: Molecules move further apart

Q: What is wavelength? A: The distance between peaks of a waveform i.e. a cycle

Q: What is frequency? A: The number cycles per second

Q: What is amplitude? A: The measure of (air) pressure in dB

Q: What is a fundamental? A: The perceived pitch of a note

Q: What is a harmonic? A: Resonant frequencies which appear in set intervals

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Q: What is electronically produced sound? A: An analogue copy of acoustic sound

Q: What is digital recording? A: Sound stored as data in binary code

Q: What is bianry code? A: A series of on-off voltage commands for computers

Q: How is sound stored on records or wax? A: Physical waveforms cut into grooves

Q: How is sound stored on tape? A: Position of ferric oxide particals on magnetic tape

Q: What is sample rate? A: The number of samples ('snapshots') of sound in 1 second

Q: How many samples ('snapshots') are in 48kHz? A: 48,000

Q: What is bit depth/resolution? A: Stepwise capture of volume

Q: What does DAC mean? A: Digital Audio Converter

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