Performance of a highly directional microphone array in a multi-talker reverberant environment

Abstract

A visually-guided hearing aid (VGHA) has recently been developed which uses an eye tracker to steer the "acoustic look direction" (ALD) of a microphone array. The current study evaluates the performance of this highly directional microphone array in providing spatial release from masking (SRM) under acoustically dry and reverberant conditions. Four normal-hearing subjects participated in a speech intelligibility test with colocated and spatially separated speech maskers when listening either through the microphone array or through KEMAR to simulate "natural" binaural conditions. The results indicated that the prototype microphone array provided performance on par with or better than the KEMAR listening condition for both tested environments. In particular, for colocated maskers in the tested reverberant condition, the array attenuated enough the off-target direction energy to provide a significantly better performance than with the KEMAR listening. The SRM was similar or slightly larger than the intelligibility-weighted signal-to-noise ratio improvement provided by the array. The conclusion is that the microphone array provides substantial source selection benefits in some reverberant conditions.