Array Processing Techniques for Broadband Acoustic Beamforming

Audio acquisition and recording can benefit from directional reception of the acoustic signals. Current acoustic designs of highly-directional microphones are bandwidth limited and physically large. A microphone array used in conjunction with a beamforming algorithm can acquire and spatially filter the signal, but traditionally this has suffered from limitations similar to those of the purely acoustic designs. The work presented in this paper attempts to overcome these limitations by producing and analyzing three atypical techniques for broadband beamforming. The last and most successful technique employs an algorithm which calculates the difference in group delay of the acquired signals and uses that information to determine the direction of the incoming signals as a function of frequency.