10P-D-4 補間関数の変更に伴う音質への影響と評価(D会場 一般講演)

抄録

The purpose of our study is to evaluate the quality of synthesized speeches by measuring the mismatch negativity (MMN) of the event-related potentials (ERPs). The proposed synthesis has required the superposition of six-channel sinusoidal interpolation between the extremal data of the filtered waveform, in which each passband had one octave, belonging to the total bandwidth of 80 to 5,120 Hz. Subjects were presented with a repetitive stimulus of an original syllable /ki/, randomly replaced at a 14.3 % probability by a synthesized one. No MMN responses were observed in the task, suggesting that the extremal data played a key role in the synthesis of the phonetic equivalence of the acoustic structure. When employing discontinuous and/or distorted interpolation, MMNs were evoked by increase of power in higher spectral channels, also enhancing the hypothesis of a simple extremal detector in the early-stage of the auditory system.