室内音場の受音点に到来する個々の反射音の特性抽出手法の開発  [in Japanese] DEVELOPMENT OF METHOD FOR DETECTION OF CHARACTERISTIC OF RESPECTIVE SOUND WAVE ARRIVED AT RECEIVING POINT IN A ROOM SOUND FIELD  [in Japanese]

This paper describes the development of a method for detecting individual characteristics of reflected sounds arriving at a sound receiving point in a sound field in a room. The development isbased on the regular tetrahedron peak point method, which we developed, for computing virtualsound sources, in combination with the spherical array microphone system, a method for measuring impulse responses by directions. In this method, we compute the arriving time and direction of each reflected sound by the regular tetrahedron peak point method in order to grasp the individual characteristics of each reflected sound arriving at a sound receiving point, then measure the directional response through spherical array microphon system in the direction of each reflected sound, separating the reflected sound of the extracted object from those of others, and finally separating it by a suitable length of time 'window from the arrival time of each reflected sound, thus extracting the time series characteristics of each individual reflected sound. Further, we give some single plate reflection experiments, verification experiments of extraction accuracy at an actual sound field, and analyses of virtual sound source distribution by frequencies in an actual sound field, thus showing a possibility in which physical characteristics of asound field can be observed in detail including directional information at the initial response.