桑原尚夫
ホルマント周波数、バンド幅の変形による
声質制御
Abstract:An analysis-synthesis system has been developed which is capable of
independent manipulation of acoustic parameters to investigate the
contribution of these individual parameters to speech quality. Formant
frequencies and their bandwidths were used as the acoustic parameters to
characterize the vocal tract configuration, and pitch frequency as the voice
source. This paper describes a method how to control the voice quality of
natural speech by manipulating the formant frequencies. Formant
trajectories extracted from a natural speech were modified to alter their movement
to some extent, and the resultant speech wave was synthesized by this method
to present to listeners for the judgement of voice quality. It was found that the
speech intelligibility or articulateness was improved to some degree when the
movement of time-varying formant pattern was slightly emphasized, but too much
emphasis would cause degradation of the voice quality.