Design and performance of a real-time acoustic beamforming system

A real-time acoustic beamforming system comprised of multiple nodes, each node having 12 MEMS microphones, was developed to process source signals in the far-field to (1) improve signal quality through distributed beamforming, and (2) provide direction selectivity for targeted listening. Speech intelligibility of beamformed signals was evaluated experimentally using a variant of the Modified Rhyme Test (MRT). Results show a mean improvement in speech intelligibility of 18% compared with single microphone recordings for 40 study participants. A statistical analysis on the improvement in speech intelligibility scores resulted in a 95% confidence interval of (16%, 21%).