Techabulary

Comfort Noise

In the case that an IP phone or gateway detects that there is silence (either as a result of no packets being transmitted or special comfort noise packets being transmitted), the device may play "noise" to the listener to provide audible confirmation that the phone connection has not broken. Without such audible indications, a party on the call may believe that the call has been disconnected.

See Also: Voice Activity Detection (VAD)