An experimental verification of iterative microphone removal beamforming arrays

Acoustic beamforming is an experimental method that is used to locate and quantify acoustic sources and is becoming increasingly popular as a research tool in academia and a competitive edge for acoustic consultants. A microphone array design method previously presented by the current authors is experimentally verified in this paper. Based on main lobe width and maximum sidelobe criteria, an array is designed such that microphones are removed from a large array stencil to arrive at a least-compromised array design. This paper presents new arrays possessing 48-channels that are designed specifically for individual frequencies and are installed within a 169-channel stencil. For each beamforming frequency of interest, the microphones are rearranged using an iterative microphone removal method to develop a well-designed array for that frequency. Eight 48-channel arrays are designed, experimentally tested and compared with expected numerical beamforming maps. Good agreement is achieved considering the reflective properties of the testing environment and size of the acoustic source.
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