Spherical microphone array for spatial sound localization for a mobile robot

The present paper introduces a microphone array design and describes the results of an evaluation of the developed microphone array. We propose an evaluation index of the directional characteristics of beamforming to optimize microphone array design. Using beamforming simulation, we obtain a microphone arrangement that minimizes sidelobes and improves the basic performance of beamforming. This microphone arrangement has 64 microphones arranged in a 350-mm-diameter sphere designed to be mounted on a mobile robot and omni-directional directivity in azimuth and elevation. The performance of the proposed microphone array is verified in different real environments. The experimental results of sound localization demonstrate the effectiveness of the array in challenging environments and the robustness of the proposed microphone array for different pressure sound sources to cover larger areas.