抄録
Securing the clear speech intelligibility is one of the most important subject on the sound reinforcement in a room. In this paper, we picked up the three-syllable sound source for the hearing test and the MTF-STI method for the physical index. The results of the three-syllable articulation test showed clearly the difference of the directivity of the sound systems, and the location of the listening points. The STI value, obtained from the measuring results of the MTF-STI on the same condition of the hearing test, showed a good correlation with the results of the three-syllable articulation test. The relationship between the properties of the arrival sound and the STI value, calculated from the imitation impulse response, was obtained. The comparison between the calculated STI value from the imitation impulse response and the results of three-syllable articuration test suggested the possibility to get the correspondence of the properties of the arrival sound to the speech intelligibility.