The audio signal in a file represents a series of samples that capture the amplitude of the sound over time. The sample rate is the number of discrete samples taken per second and given in hertz. The precision of the samples, measured by the bit depth (number of bits per sample), depends on the available audio hardware.
MATLAB® audio functions read and store single-channel (mono)
audio data in an
m-by-1 column vector,
and stereo data in an
m-by-2 matrix. In
m is the number of samples.
For stereo data, the first column contains the left channel, and the
second column contains the right channel.
Typically, each sample is a double-precision value between -1 and 1. In some cases,
particularly when the audio hardware does not support high bit depths, audio files store
the values as 8-bit or 16-bit integers. The range of the sample values depends on the
available number of bits. For example, samples stored as
can range from 0 to 255 (28 – 1). The MATLAB
soundsc functions support only single- or double-precision values
between -1 and 1. Other audio functions support multiple data types, as indicated on the
function reference pages.