Broadband signal recording for a baffled circular microphone array using circular harmonics decomposition

The relationship between the signals recorded by a circular microphone array (CMA) and the sound pressure distribution is analysed in this paper. By applying circular harmonics (CH) decomposition to the sound pressure, the analytic expression of the sound pressure distribution around a CMA baffled on an infinite-length rigid cylinder is formulated. Signal recording models for both single frequency and broadband signals are also established under unbaffled and baffled cases. Further more, an overlap processing method is employed to alleviate the distortions produced during the segment-divided processing. Computer simulations are conducted to demonstrate the broadband signals recorded by unbaffled and baffled CMAs, and the improved performance of overlap processing.