Audio signals can be converted to digital information through a measurement process called sampling.
One common, and useful, digital representation of an audio signal records the amplitude at regular intervals of time. This representation is called pulse code modulation (PCM). Here are a few links to find out more about PCM: video, wikipedia.
The number of amplitude measurements, or samples, per second is called the sampling rate. For audio, common sampling rates include 44,100 samples/second (CD Audio) and 48,000 samples/second (DVD Audio).
After an audio signal is digitized, the samples can be organized in sequential order. In Matlab, the samples in an audio signal can be stored as the elements in an array.
Next, let’s look at several built-in functions for working with audio signals. First, a function for importing an audio file stored on a computer’s hard drive into Matlab.