Enhanced Microphone-Array Beamforming Based on Frequency-Domain Spatial Analysis-Synthesis

Distant-talking hands-free communication is hindered by reverberation and interference from unwanted sound sources. Microphone arrays have been used to improve speech reception in adverse environments, but small arrays based on linear processing such as delay-sum beamforming allow for only limited improvement due to low directionality and high-level sidelobes. In this paper, we propose a beamforming system that improves the spatial selectivity by forming multiple steered beams and carrying out a spatial analysis of the acoustic scene. The analysis derives a time-frequency mask that, when applied to a reference look-direction beam, enhances target sources and improves rejection of interferers that are outside of the specified target region. The performance of the system is demonstrated by simulations and audio examples.