Patent ID: 7130799

Claim:
A method for synthesizing speech with an apparatus comprising a sound source for generating a frequency signal, a vocal tract filter for filtering said frequency signal to generate a speech waveform signal, said filter having characteristics corresponding to a linear predictive coefficient calculated from respective phonemes in a phoneme series, comprising the steps of: inputting the phoneme series into the apparatus; dividing each of said phonemes into N frames, each of said N frames having a predetermined time length; summing squares of speech samples in each of said N frames as a frame power value for each frame, respectively; standardizing frame power values at head and tail frames in one phoneme to predetermined values, respectively, to obtain a standardized frame power value of an n-th frame, wherein (1<n<N); summing squares of signal levels of an n-th frame in said frequency signal to obtain a frame power correction value for the n-th frame; and calculating a speech envelope signal by means of a function comprising variables of said standardized frame power value of the n-th frame and said frame power correction value for the n-th frame, and outputting an amplitude adjusted waveform signal by adjusting an amplitude level of said speech waveform signal based on the speech envelope signal.