Simulated analysis and hardware implementation of voiceband circular microphone array

Acoustic microphone array beamforming represents an adequate technology for remote acoustic surveillance and multi conference recording, as the system has no mechanical parts and it has moderate size. This paper contains both the simulated analysis and hardware implementation of an 8-channel uniform circular array operating with fixed filter-and-sum (FaS) beam-forming. The hardware implementation comprises essentially the analog and the digital parts. In the analog part, the array frame with high-sensitivity small electret microphones and low-noise JFET-based microphone preamplifiers were built. In the digital part, a multi-channel audio DSP board was used to sample the preamplifiers output and implement the real-time FaS digital processing. The real performance analysis of the prototype in medium-sized meeting rooms was successfully carried out.