Axisymmetric directional microphone model for spherical harmonic decomposition of sound field

[摘要] Spherical microphone array based on spherical harmonic expansion is used in wide range of applications such as sound field reproduction and beamforming [1,2]. Arrays are popularly configured with a rigid sphere mount or with cardioid directional microphones to avoid indefinite solutions when estimating spherical harmonic expansion coefficient which is radial-independent [3]. In this case, a radial function is introduced to model the ideal rigid sphere or cardioid directivity. However, because of the size of the actual microphone diaphragm, the directivity deviates from the model, especially at high frequencies. Therefore, a flexible model that can fit those deviant directivity is required.

[学科分类] 声学和超声波

[关键词] Spherical microphone array;Radial function;Axisymmetric directivity;Higher-order pressure gradient