Research on the amplitude mismatch in dual-microphone device

Array-based speech enhancement technology uses the spatial information for noise suppression, especially for situation that the desired speech and ambient noise originate from different orientations. For pocket mobile devices, such as hearing aid and cochlear implant, the size constraint is one of the keys in product design, so the dual-microphone system is more suitable for these applications. However, the actual microphone is different from the ideal one in theoretical analysis and algorithm design, and the mismatch between microphones always exists. The nuances of the microphone sensitivity and the gain difference in dual-channel amplifiers can both result in amplitude mismatch. This paper focuses on the research of amplitude-mismatch characteristic and the corresponding influences in beamforming and noise suppression.