4.5 Comfort Noise
A random number generator generates the comfort noise, and its frequency response is constant across all frequencies. The main purpose is to provide a constant noise level to prevent the speech codec algorithm of host cell phones from injecting unwanted noise, which degrades speech clarity at the far-end listener side.
Note: Background noise adjusts the level
of the comfort noise.
The following figure illustrates the parameters to adjust the configuration of the
digital MIC gain and comfort noise.