Perceptually motivated coherence preservation in multi-channel wiener filtering based noise reduction for binaural hearing aids

Besides noise reduction an important objective of binaural speech enhancement algorithms is the preservation of the binaural cues of both desired and undesired sound sources. Recently, an extension of the binaural Multi-channel Wiener filter (MWF), namely the MWF-IC, has been presented, which aims to preserve the Interaural Coherence (IC) of the noise component. Since for the MWF-IC a substantial trade-off between noise reduction and IC preservation exists, in this paper we propose a perceptually constrained version of the MWF-IC, where the amount of IC preservation is controlled based on psychoacoustic criterias of the IC discrimination ability of the human auditory system. In addition, we present a simplified version of the MWF-IC, resulting in a decrease of computational complexity. Experimental results show that the perceptually motivated MWF-IC and its simplified version yield a very similar performance and the loss in intelligibility weighted output SNR compared to the binaural MWF can be limited to 0.5 dB, whereas the spatial separation between the output speech and noise component is increased leading to better perceptual results.