On the design of time-domain differential microphone arrays

Abstract

Differential microphone arrays (DMAs) are characterized as compact superdirective beamformers whose beampatterns are almost frequency invariant. In this work, we present a time-domain design of Nth-order DMAs, which is important in some applications where minimal delay is required, such as real-time audio communications. Moreover, design in the time domain can reduce the computational efforts, compared to the frequency-domain design, especially when short filters are sufficient. We present design examples for DMAs illustrating some of the fundamental properties of the time-domain implementation as well as the equivalence to the frequency-domain design approach.