Interaural Coherence Induced Ideal Binary Mask for Binaural Speech Separation and Dereverberation

Abstract

We have proposed a spatial-cue based binaural noise reduction algorithm for hearing aids. However, in that algorithm, decision parameters are empirically selected. In this paper, we extend the work and propose a supervised classification algorithm for binaural speech enhancement/separation and dereverberation using a modified ideal binary mask (mIBM) as the training target and simple neural networks (NNs) as classifiers. The low complexity of the simple NNs makes the proposed algorithm practical for binaural hearing aids. The interaural time difference (ITD) and the interaural level difference (ILD) of each T-F unit are extracted as the basic binaural features. For the purpose of dereverberation, the interaural coherence (IC) is also considered when building the target mIBM and training the NNs. For separation evaluations, our method yields comparable performance to a more complicated benchmark system, which cannot de-reverb the signal. For concurrent separation and dereverberation, our method offers 4 to 5 dB improvement on the frequencyweighted segmental speech-to-noise ratio (SNRfw) over unprocessed speech.