Adaptive Close-Talking Beamforming with a Novel Differential Array

Aiming at the application of arrays for close-talking, a novel type of differential microphone arrays is proposed, and a nearfield GSC (generalized sidelobe canceller) with a novel differential array is developed. Unlike the traditional farfield GSC, the nearfield GSC algorithm adopts different signals as inputs in different modules, resulting in improvement in adaptive noise cancellation. Simulations with real data acquired by a differential array in an anechoic chamber show that the proposed beamformer effectively improves the close-talking capability of the array with the SNR increase of over 12 dB. Furthermore, a DSP-based real-time beamforming system with a small differential array embedded into a handset housing exhibits the noise-cancellation capability of 10-15 dB.