Patent ID: 7562018

Claim:
A speech synthesis method comprising the steps of: (a) removing only a phase fluctuation component from a speech waveform containing the phase fluctuation component by cutting a speech waveform in pitch period units using a predetermined window function, determining first DFT (discrete Fourier transform) of first pitch waveforms which are cut speech waveforms, and transforming the first DFT to second DFT by changing the phase of each frequency component of the first DFT to a value of a desired function having only the frequency as a variable or a constant value; (b) imparting only a new phase fluctuation component in a high frequency region of the speech waveform obtained by removing the phase fluctuation component in the step (a); and (c) outputting synthesized speech through a speaker device using the speech waveform obtained by imparting the new phase fluctuation component in the step (b).