Method for detecting speech activity

The present invention relates to digital speech signal processing techniques. It relates more particularly to techniques which detect vocal activity to perform different processing according to whether the signal is supporting vocal activity or not. A digital speech signal processed by successive frames is subjected to noise suppression taking account of estimates of the noise included in the signal, updated for each frame in a manner dependent on at least one degree of vocal activity. A priori noise suppression is applied to the speech signal of each frame on the basis of estimates of the noise obtained on processing at least one preceding frame, and the energy variations of the a priori noise-suppressed signal are analyzed to detect the degree of vocal activity of said frame.