抄録
It is well known that voice timbre in autophonic production (hearing one's own voice during phonation) is different from that in extraphonic production (hearing one's voice after recording). The differences between the two productions, however, have not been evaluated quantitatively. This results naturally from the fact that there is no objective way to evaluate the voice timbre in autophonic production. The purpose of the present study was to show a method, named the delayed feedback method created by the author, in which voice timbre in autophonic production can be examined objectively, as a function of frequency, and then to evaluate the timbre in comparison with that in extraphonic production quantitatively, when male subjects phonated five Japanese vowels in the spoken mode. The experiment was conducted so as to simulate the sound through a loudspeaker as accurately as possible in its timbre and loudness to that perceived during phonation. It was found that, for all the vowels, the vocal sound was perceived relatively louder in the low frequency region (about 5 dB at 100 Hz) and softer in the high frequency region (about -5 dB at 4 kHz) than the reproduced sound after recording. This may result from the bone conduction elements during phonation. The findings obtained do also, in fact, coincide with experiences in everyday life.
