Extrapolated open spherical microphone arrays beamforming for acoustic source localization

Abstract

Spherical microphone arrays have become a particular tool for analyzing the spatial sound field, especially in source localization and identification. Spherical Harmonic Beamforming (SHB) is a fundamental algorithm with the spherical microphone arrays in aeroacoustics. However it presents some intrinsic limitations, specific poor resolution and sidelobe suppression capability. This paper aims to overcoming this limitations by employing Functional Beamforming and Beamforming Regularization Matrix. Functional beamforming has a narrower the mainlobe width and lower sidelobes by increasing the order of matrix functions. To improve the performance of algorithm at low frequency, this paper uses an extrapolated spherical arrays that is a larger radius of the spherical arrays through the Beamforming Regularization Matrix algorithm which can improve the spatial resolution. The results of numerical simulations and experiments show that the proposed method can remarkably suppress beamforming sidelobes, improve dynamic range of the system，and obtain a higher array gain, which leads to the accurate identification the location of sound sources.