4チャンネルマイクロホンシステムを用いた正四面体頂点法による室内音場の解析

Abstract

This paper describes the development of a sound field measurement method which is aimed at analyzing spatial information of the sound field in a room. This measurement system, which we have developed, has 4 microphones and each of them is installed at the peak point of a regular tetrahedron. With this method, spatial information of individual wave front is analyzed from the impulse responses of four points which are completely synchronized. With the introduction of a deconvolution method, measuring accuracy for waveform analysis is greatly improved and the analysis operation becomes much faster. By using models of which the image source positions already known, we have conducted experimental studies on the identification of sound source positions and frequency distortion by repeated reflection. Furthermore, we have detected virtual sound sources and have recomposed the waveform in actual sound fields. The results of these experiments indicate that the measurements are accurate and that the measurement method can be used effectively.