Reference Guide

822 Editing audio

Digital audio fundamentals

Digital audio is a numeric representation of sound; it is sound stored as numbers. In order to

understand what the numbers mean, you need to start with the basic principles of acoustics, the

science of sound.

See:

“Basic acoustics” on page 822

“Example—a guitar string” on page 823

“Waveforms” on page 825

“Recording a sound” on page 827

“The decibel scale” on page 828

“Audio clips” on page 828

“Managing audio data” on page 829

Basic acoustics

Sound is produced when molecules in the air are disturbed by some type of motion produced by a

vibrating object. This object, which might be a guitar string, human vocal cord, or a garbage can, is

set into motion because energy is applied to it. The guitar string is struck by a pick or finger, while the

garbage can is hit perhaps by a hammer, but the basic result is the same: they both begin to vibrate.

The rate and amount of vibration is critical to our perception of the sound. If it is not fast enough or

strong enough, we won't hear it. But if the vibration occurs at least twenty times a second and the

molecules in the air are moved enough, then we will hear sound.

See:

“Digital audio fundamentals” on page 822