Digital Sound & Music: Concepts, Applications, & Science, Chapter 5, last updated 6/25/2013

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Figure 5.2 Analog and digital components in a DAW

Understanding the digitization process paves the way for understanding the many ways

that digitized sound can be manipulated. Let’s look at this more closely.

5.1.2 Digitization

5.1.2.1 Two Steps: Sampling and Quantization

In the realm of sound, the digitization process takes an analog occurrence of sound, records it as

a sequence of discrete events, and encodes it in the binary language of computers. Digitization

involves two main steps, sampling and quantization.

Sampling is a matter of measuring air pressure amplitude at equally-spaced moments in

time, where each measurement constitutes a sample. The number of samples taken per second

(samples/s) is the sampling rate. Units of samples/s are also referred to as Hertz (Hz). (Recall

that Hertz is also used to mean cycles/s with regard to a frequency component of sound. Hertz is

an overloaded term, having different meanings depending on where it is used, but the context

makes the meaning clear.)

Quantization is a matter of representing the amplitude of individual samples as integers

expressed in binary. The fact that integers are used forces the samples to be measured in a finite