FIRST ORDER DIFFERENTIAL MICROPHONE ARRAYS FOR AUTOMOTIVE APPLICATIONS

Abstract

Differential microphone arrays promise high directional gain with compact arrangements. However, they also come with the problem that even small deviations in microphone properties can cause severe degradation of the array’s performance. For automotive applications the effects of microphone deviations have to be reduced. In this paper the performance of first order differential arrays is examined. The frequency dependence of the important parameters is thoroughly investigated. This paper contributes the expression for the frequency dependent directivity index, which is published for the first time for differential arrays. Furthermore a new approach to model effects of microphone deviations for low frequencies is presented.