To identify sound source locations by using Near-field Acoustical Holography (NAH), a large number of microphone measurements is generally required in order to cover the source region and to ensure a sufficiently high spatial sampling rate. It may be the case that hundreds of microphones are required, so such measurements are economically expensive, which has limited the industrial application of NAH to the identification of sound source locations. Recently, however, it has been shown possible to identify concentrated sound sources with a limited number of microphone measurements based on Compressive Sampling theory. In the present work, a loudspeaker was used as a sound source and a near-field intensity scan was conducted to measure the true sound field and sound power generated by the loudspeaker. Then by using exactly the same measured data, four NAH methods were used to reconstruct the sound field: i.e., Statistically Optimized Near-Field Acoustical Holography (SONAH), Wideband Holography (WBH), l1-norm minimization and a hybrid compressive sampling method. The number of microphone measurements used to reconstruct the sound field was decreased systematically by increasing the spacing between microphones. Then the reconstruction results were compared with the measured intensity results, and the benefits of the compressive sensing are illustrated.
Nearfield acoustical holography, Equivalent source methods, Compressive sensing, Source identification, SONAH, Wideband acoustical holography
Acoustics and Noise Control
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