Abstract:In order to improve the holography accuracy of multiple sources on irregular structure surface, a Nearfield Acoustic Holography for multiple sources on irregular structure surface is presented based on spherical harmonic wave superposition and sound source identification. The positions of the sound sources are determined by the theory of sound source depth identification and localization, the 3D sound field distributions are described by spherical harmonic wave superposition from different sound sources location. Then the sound fields are reconstructed by the existing theory of spherical harmonic wave superposition from the same point. The methodology is validated and the accuracy of acoustic field reconstruction is examined numerically in the crowded sound field and the discrete sound field, respectively, and it is compared with the existing method which depict sound field with spherical waves from one local coordinate origin. The results show that when the sound sources are crowded together, the results of sound field reconstruction by the two methods are all satisfied and the reconstruction error is less than 5%. When the sound sources are discrete, the result of the existing method is failed, but the proposed method can generate sound pressure distribution precisely, and the reconstruction error is almost less than 20%. Further comparative experiments are carried out with three loudspeakers in anechoic box, the results show that the reconstruction error can be reduced by 14.08% averagely, and the holography accuracy of the multiple sources in irregular spatial position is improved significantly.