Comparison of binaural multichannel Wiener filters with binaural cue preservation of the interferer

An important objective of binaural speech enhancement algorithms is the preservation of the binaural cues of the sources, in addition to noise reduction. The binaural multichannel Wiener filter (MWF) preserves the binaural cues of the target but distorts the noise binaural cues. To optimally benefit from binaural unmasking and to preserve the spatial impression for the hearing aid user, two extensions of the binaural MWF have therefore been proposed, namely, the MWF with partial noise estimation (MWF-N) and MWF with interference reduction (MWF-IR). In this paper, the binaural cue preservation of these extensions is analyzed theoretically. Although both extensions are aimed at incorporating the binaural cue preservation of the interferer in the binaural MWF cost function, their properties are different. For the MWF-N, while the binaural cues of the target are preserved, there is a tradeoff between the noise reduction and the preservation of the binaural cues of the interferer component. For the MWF-IR, while the binaural cues of the interferer are preserved, those of the target may be slightly distorted. The theoretical results are validated by simulations using binaural hearing aids, demonstrating the capabilities of these beamformers in a reverberant environment.