Improved algorithm of near-field beamforming for sound source identification

In order to improve the sound source identification performance of near-field beamforming and the calculation accuracy of maximum sound pressure contribution on the array plane, the influence of array microphone signal amplitude correction to acoustical imaging and sound source identification was analyzed by using the cross- spectra beamforming algorithm with auto-spectra exclusion based on the assumption of spherical wave. The results indicated that the calculation accuracy of the maximum sound pressure contribution on the array plane was improved, and some shortages such as the increase of the maximum side-lobe level and the reduction of the dynamic range were come out in the meantime. Ulteriorly, the improved near-field beamforming algorithm for the calculation of the sound pressure contribution on the array plane was put forward. Both results of simulation and the experiments showed that the improved algorithm could calculate the maximum sound pressure contribution accurately, and the dynamic range was increased 1.0-1.6 dB. Finally, the acoustical sealed performance test for a car was carried out by using the improved algorithm. The weak positions of the acoustical seal were identified precisely.