A hybrid acoustic holography technique based on beamforming and wave superposition algorithm

Near-field Acoustic Holography (NAH) is an accurate noise source identification technique. However, it processes the disadvantages of the strictness of measurement requirements and needing of a large number of microphones, which restricts its widely applications in industry situations to some extent. A hybrid acoustic holography technique based on beamforming and the wave superposition algorithm was presented, which overcame the above disadvantages of NAH. At first, a microphone array was used to acquire the sound pressure field radiated from a vibrator; then a beamforming algorithm was adopted to localize sound sources; after that, a serial of equivalent sound sources were collocated around these sound sources; at last, the wave superposition algorithm was applied to reconstruct the sound field. It processes the advantages of needing of a small quantity of microphones, a mid-long measurement distance, easiness and efficiency of sound field reconstruction. Numerical simulations were performed based on a two-pulse-ball model; and also experiments were carried out in a semi-anechoic chamber by using two sound boxes to simulate the sound sources. Both of numerical simulations and experimental results had accurately reconstructed the exterior sound field of the models. It was showed that this hybrid technique can exactly reconstruct the exterior sound field of radiators, which will make a base to its applications in industry situations.