A Post-Filtering for Performance of Differential Microphone Array

Abstract

Microphone array (MA) is a perspective technique for speech enhancement, because of its simplicity and low computation. MA can be decomposed into a concatenation of a spatial filtering, which provides beampattern toward a certain target directional speech source while attenuating noise, interference or third-party speaker from other directions, and a post-filtering, which suppresses the remaining noise at the final output signal. Differential Microphone Array (DIF) is one basic MA, which has many advantages for extracting the desired speech and null-steering to direction of noise. Nevertheless, in real situation, the performance of DIF often deteriorated due to phase error, imprecise the Direction-Of-Arrival (DOA) of interest signal, microphone mismatches or imperfect distribution of MA, which significantly degrade the performance and the speech quality of DIF. In this article, the author proposed a Post-Filtering (PF), which based on the properties of considered recording environment DOA to enhance the speech quality of target speaker and reduce the other non-target speaker at the opposite direction. Experimental results were verified in real scenario with dialogue between two speakers, which stand opposite direction, and show the effectiveness of the suggested PF when compared with the author’s previous work