抄録
By using a pressure responding microphone placed in close proximity to a rigid boundary, called the "Boundary-Effect Microphone", not only the direct sound is increased by 6dB, but also the direct to reverbrant ratio is increased by 3dB in a live room. In this paper, this phenomenon is theoretically analyzed under conditions of stady-state and transient-state, and cofirmed experimentally. Experimental results show good agreement between the calculated and measured values. In order to evaluate the clarity of sound, the relation between physical and psychological factors are clarified. It is conclued that the direct sound in hearing is defined as a set of direct physical sound and the following reflections within 10 ms of frequency bands above 1kHz. Finary, the method to apply Boundary-Effect Microphone to council miking and stereo miking is examined.
