Patent ID: 6061647
Filing Date: 2000-05-09
Classification: G10L,H04M,H04Q

Abstract:
A voice activity detector for detecting the presence of speech in an input signal which comprises a noise component, said detector comprising:(a) means for storing an estimate of the noise component of an input signal;(b) means for recognizing a spectral similarity of the input signal and the stored estimate to produce an output decision signal;(c) means for updating the stored estimate;(d) an auxiliary detector arranged to indicate the absence of speech from the input signal and control the means for updating so that updating occurs only when speech is indicated by the auxiliary detector to be absent from the input signal;(e) means operable to calculate a measure of the prediction gain for the input signal;(f) modifying means arranged to suppress said updating of the stored estimate in the event that the prediction gain exceeds a threshold value.