College of Sci. and Technol., Nihon Univ., 1-8 Kanda-Surugadai, Chiyodaku, Tokyo, Japan
This paper describes the development of a sound field measurement method that is aimed at analyzing spatial information of the sound field in a room. This measurement system has four microphones and each of them is installed at the apex of a regular tetrahedron. With this method spatial information of an individual wave front is analyzed from the impulse response at four points that are completely synchronized. With the introduction of a deconvolution method, measuring accuracy for waveform analysis is greatly improved and the analysis becomes much faster. By using models for which the image source positions are already known, experimental studies have been conducted on the identification of sound source positions and frequency distortion by repeated reflections. Furthermore, virtual sound sources have been detected and the waveform in actual sound fields have been recomposed. The results of these experiments indicate that the measurements are accurate and the measurement method can be used effectively.