Reconstruction of interior sound field with spherical microphone array

This paper presents the results of an experimental study on the methodology of spherical nearfield acoustic holography (spherical NAH) to reconstruct interior sound field. The experiment was carried out in a full anechoic chamber, in which the sound filed was generated with different combination of speakers at different positions, and a rigid spherical array was used to collect the field acoustic pressures as input to the reconstruction calculation. There are three cases which were investigated. In case 1, a source was set near to the microphone array. In case 2, two sources were eccentrically set opposite to each other around the microphone array. And in case 3, two sources were placed on one side of microphone array on the same orbit, while they were positioned apart at a small angle. The accuracy of the reconstruction of sound field was examined and analyzed compared with the benchmarks and the results of the numerical simulations. The reconstructed results show that the methodology of Spherical NAH is capable to locate sources and reconstruct sound field within certain accuracy. © 2013 by CESER Publications.