Speech Enhancement in Hearing Aids Using Target Speech Presence Estimation Based on a Delayed Remote Microphone Signal

Speech enhancement in hearing aids (HAs) can take advantage of a wireless remote microphone (RM) having a better signal-to-noise ratio than the HA microphones. However, using the RM effectively is complicated by the time delay between the acoustic and wireless signals. Methods in the literature assume an instantaneous transmission of the RM signal, which is never the case in practice. Hence, we propose a practically operational method to use an RM with HAs in the presence of wireless transmission delays. Specifically, we use the delayed target voice activity state from the RM signal, to derive an expression for target speech presence probability (SPP) at the local HA microphone signals. The proposed method uses this target SPP mask as a post-filter that follows a local multichannel Wiener filter. Through simulations, we demonstrate that the proposed method improves speech quality and intelligibility metrics, especially in very noisy acoustic environments, compared to a standard approach which relies solely on HA microphones.