Steerable adaptive first- and second-order differential microphones

Abstract

Directional microphone arrays are spatial filters that can be designed to improve the sound quality of speech in audio telecommunication by removing acoustic signals arriving from undesired directions. Recently, there has been a large interest in adaptive microphone systems (also sometimes referred to as ‘‘smart microphones’’), since these systems automatically self-adjust their spatial response to minimize acoustic interference and thereby increase the desired signal-to-noise ratio. The talk will present adaptive first- and second-order differential microphone arrays that have fixed look directions dependent on the array geometry. A generalized version of the adaptive first-order system will then be presented where the look direction can be arbitrarily oriented (independent of the array spatial orientation). The commensurate problem of acoustic echo cancellation with adaptive microphones will also be discussed and some potential solutions given.