Real-time dual-channel speech enhancement by VAD assisted MVDR beamformer for hearing aid applications using smartphone.

In this paper, a dual-channel speech enhancement (SE) method is proposed. The proposed method is a combination of minimum variance distortionless response (MVDR) beamformer and a super-Gaussian joint maximum a posteriori (SGJMAP) based SE gain function. The proposed SE method runs on a smartphone in real-time, providing a portable device for hearing aid (HA) applications. Spectral Flux based voice activity detector (VAD) is used to improve the accuracy of the beamformer output. The efficiency of the proposed SE method is evaluated using speech quality and intelligibility measures and compared with that of other SE techniques. The objective and subjective test results show the capability of the proposed SE method in three different noisy conditions at low signal to noise ratios (SNRs) of -5, 0, and +5 dB.