능동음원 및 벽면 어드미턴스 측정을 통한 실내 소음원 규명

Abstract

Nearfield acoustic holography [J. D. Maynard, and et al, J. Acoust. Soc. Am, 78, 1395-1413, 1985] has been used to reconstruct sound fields near sound sources. The reconstructed sound fields show noise source locations in exterior sound fields. However, in enclosures, the reconstructed sound fields generally do not show correct source locations. Since reflections are included in the field, the spatial distribution of reconstructed values does not coincide with source distribution. In this paper, we introduce a method to estimate active sources in enclosures. After eliminating the effect of reflections, we estimate the distribution of the sources that actively radiate sound into enclosures. An in-situ technique to measure surface admittance is also proposed. We use the surface admittance to eliminate the effect of reflections. Numerical simulations and experiments in two-dimensional sound fields verify the method.