Wideband Adaptive Beamforming System for Speech Recording

An adaptive beamforming algorithm that enhances the quality of the signal recorded by a microphone array is presented. The system described here attenuates the interference from spatially scattered sources while preserving the desired signal quality in the speech frequency range. A novel method for defining additional constraints within the adaptation process and performing beamforming in parallel across several frequency bands achieves undistorted recording even with slight errors in localizing the speaker. Simulation results show nearly optimal improvement of speech quality in various noisy environments. The algorithm is modified to perform in a real environment by introducing two modes of adaptation that switch according to the speaker activity. The implementation of this modified system demonstrates SNR gain close to that of the original simulated system. It is robust to localization errors and non-ideal environmental effects.