Minimum phase whitening filter to speech beamforming technique

Abstract

This paper presents application of minimum phase whitening filter for speech enhancement technique to twomicrophone beamforming structure. The method uses switching technique for updating the estimate alternately between frontend minimum phase whitening filter during speech plus noise period and rear-end adaptive finite impulse response (FIR) filter during noise alone period.For application of speech beamforming technique, innovations-based minimum phase whitening filter is applied in front of sum and subtract (SS) function with the use of one sample delay filter in rear-end primary input. A test result shows that the proposed approach by alternately switching minimum phase whitening filter and adaptive FIR filter provides an improved performance of 5.9dB and 18.03dB in signal-to-noise ratio (SNR) in stationary noise and non-stationary noise, respectively than adaptive Griffiths and Jim (G-J) beamformer by alternately switching two adaptive FIR filters. Keywords; minimum phase whitening filter; adaptive beamformer; innovations-based Wiener filtering approach; adaptive noise cancellingI.