Audio Processes

2 Audio Data Fundamentals

2.1	The Nature of Sound
2.1.1	Sound in the Time Domain
2.1.2	Cycle Length, Frequency, and Amplitude
2.1.3	Construction and Deconstruction with Sinusoids
2.2	Sound as Numbers
2.2.1	Overview
2.2.2	Sampling Continuous Data
2.2.3	A Complete Digital Audio System
2.2.4	Choosing a Sample Rate
2.2.5	Amplitude

2.1 The Nature of Sound

2.1.1 Sound in the Time Domain

The acoustic form of sound is varying air pressure, which is sensed by the human auditory system and interpreted as audio information. An audio process deals with an information form that is analogous to these air pressure variations, such as voltages or numerical data streams. The conversion between these forms is considered later, but first it is worth examining the basic characteristics ...