Dual-microphone noise reduction for mobile phone application

This paper addresses the dual-microphone noise reduction problem in mobile phone application. We propose to use the inter-microphone Posteriori SNR Difference (PSNRD) for Speech Presence Probability (SPP) estimation, which is more robust than the Power Level Difference (PLD) that is often used previously. Additionally, we use the recently reported multichannel minimum variance distortionless response (MVDR) filter for noise reduction. We divide the noises into quasi-stationary and transient components, and propose an SPP-based noise correlation matrix estimator. Analysis and experiments on data recorded in real environments verify the robustness of the PSNRD. The SPP-based estimator is more appropriate for the MVDR filter in tracking transient noise, and the proposed MVDR filter can lead to high noise reduction and small speech distortion.