A multichannel speech/silence detector based on time delay estimation and fuzzy classification

Discontinuous transmission based on speech/pause detection represents a valid solution to improve the spectral efficiency of new-generation wireless communication systems. In this context robust voice activity detection (VAD) algorithms are required, as traditional solutions present a high misclassification rate in the presence of the background noise typical of mobile environments. The fuzzy voice activity detector (FVAD) proposed by Beritelli, Casale, and Cavallaro (see Contribution ITU-T, Study Group 16, question 19/16, Washington, September 1997), shows that a valid alternative to deal with the problem of activity decision is to use methodologies like fuzzy logic. In this paper we propose a multichannel approach to activity detection using both fuzzy logic and time delay estimation. Objective and subjective tests confirm a significant improvement over traditional methods, above all in terms of a reduction in activity increase for nonstationary noise.