Apparatus and method for voice activity detection in a communication system

The present invention relates generally to voice activity detection and, more particularly, to voice activity detection within communication systems. In order for the Voice Activity Detector (VAD) decision to overcome the problem of being over-sensitive to fluctuating, non-stationary background noise conditions, a bias factor is used to increase the threshold on which the VAD decision is based. This bias factor is derived from an estimate of the variability of the background noise estimate. The variability estimate is further based on negative values of the instantaneous SNR.