Time Delay Histogram Based Speech Source Separation Using a Planar Array

Bin-wise time delay is a valuable clue to form the timefrequency (TF) mask for speech source separation on the twomicrophone array. On widely spaces microphones, however, the time delay estimation suffers from spatial aliasing. Although histogram is a simple and effective method to tackle the problem of spatial aliasing, it can not be directly applied on planar arrays. This paper proposes a histogram-based method to separate multiple speech sources on the arbitrary-size planar array, where the spatial aliasing is resisted. Time delay histogram is firstly utilized to estimate the delays of multiple sources on each microphone pair. The estimated delays on all pairs are then incorporated into an azimuth histogram by means of the pairwise combination test. From the azimuth histogram, the direction-of-arrivals (DOAs) and the number of sources are obtained. Eventually, the TF mask is determined based on the estimated DOAs. Some experiments were conducted under various conditions, confirming the superiority of the proposed method.