| 摘要 |
PURPOSE:To automatically make the wavelength of a window waveform follow up a formant sound having an extremely high pitch. CONSTITUTION:A phase generator 2 generates resetting timing which has time intervals corresponding to the frequency data fo of a phase generator 4 and a phase generator 12 according to frequency data fo corresponding to the pitch. A correction table 7 corrects the frequency data f0 so that the phase generator 12 overflows without fail when the phase generator 4 overflows. The phase generator 12 and a sin<2> (x/2) table 13 generate a window waveform on the basis of the corrected frequency data f0' when f0' >= fbw or a band width frequency fbw when f0'<fbw. An accumulation output based upon the formant center frequency ff of the phase generator 3 is supplied as address data to a sinx table 5 and sin wave data read out of this sinx table 5 is multiplied by the window waveform to generate a formant sound signal. |
