voice activity detector vad 610 can be used to determine when not to perform the gsc update and instead directly suppress the noise in noise only segments of speech we use a modification to the discontinuity in the detection because vad gives a 0 1 indicator which signals speech muted and active respectively both vad errors and the speech activity 39 s frequent changes would make the output speech discontinuous and uncomfortable if the detected non speech parts are fully canceled by setting the non speech parts to 0 however long time non speech parts can be fully cancelled without perceptual discomfort while a short time non speech part cannot the voice activity detection is therefore followed by detecting 620 noise only segments if there are a sufficient number of such segments 625 in a neighborhood of segments the noise suppression 627 can be performed otherwise proceed with overlapping speech os detection 630 in automatic overlapping speech os detection asd 640 there can be an array 501 of two or more microphones and arbitrary number n of audio signal sources the detection can be frame by frame on the observed data x i 501 i 1 2 is the microphone index for any pair of microphones in the array the observed data are obtained by audio signals acquired by the array of microphones in particular the audio signal includes speech from a target.