A VAD-robust Multichannel Wiener Filter algorithm for noise reduction in hearing aids

The Speech Distortion Weighted Multichannel Wiener Filter (SDW-MWF) is a promising multi-microphone noise reduction technique, in particular for hearing aid applications. Its benefit over other techniques has been shown in several theoretical and experimental contributions. In theoretical studies, a single target speech source is commonly assumed, as this facilitates the analysis. In this contribution, we first prove that an algorithm, that implicitly assumes a single target speech source, is also more robust against estimation errors in the speech second order statistics, compared to a standard SDW-MWF algorithm. Secondly, as any SDW-MWF algorithm relies on a voice activity detector (VAD), a novel VAD-robust extension is also proposed. It is shown theoretically and through experiments with a realistic VAD that the new algorithm indeed achieves a good performance, even at low input SNR's where the VAD error rate is high.