A hybrid microphone array post-filter in a diffuse noise field

This paper proposes a hybrid post-filter for microphone arrays with the assumption of a diffuse noise field, where few postfilter performs well, to suppress correlated as well as uncorrelated noises. In the proposed post-filter, a modified Zelinski post-filter is applied to the high frequencies to suppress spatially uncorrelated noise and a single-channel Wiener post-filter is applied to the low frequencies for cancellation of spatially correlated noise. In theory, the proposed post-filter follows the framework of the multi-channel Wiener filter. In practice, experiments using multi-channel noise recordings were conducted and results show that the proposed hybrid post-filter gives the highest SNR improvements and lowest speech distortion among the tested post-filters in various car environments.