Ratios of powers at the peaks of respective formants of the spectrum of a pitch-cycle waveform and powers at boundaries between the formants are obtained and, when the ratios are large, bandwidth of window functions are widened and the formant waveforms are generated by multiplying generated sinusoidal waveforms from the formant parameter sets on the basis of pitch-cycle waveform generating data by the window functions of the widened bandwidth, whereby a pitch-cycle waveform is generated by the sum of these formant waveforms.
SPEECH SYNTHESIZING APPARATUS AND METHOD THEREOF