Speech synthesizer, speech synthesis method and computer program product

摘要

According to one embodiment, a first storage unit stores n band noise signals obtained by applying n band-pass filters to a noise signal. A second storage unit stores n band pulse signals. A parameter input unit inputs a fundamental frequency, n band noise intensities, and a spectrum parameter. A extraction unit extracts for each pitch mark the n band noise signals while shifting. An amplitude control unit changes amplitudes of the extracted band noise signals and band pulse signals in accordance with the band noise intensities. A generation unit generates a mixed sound source signal by adding the n band noise signals and the n band pulse signals. A generation unit generates the mixed sound source signal generated based on the pitch mark. A vocal tract filter unit generates a speech waveform by applying a vocal tract filter using the spectrum parameter to the generated mixed sound source signal.

主权项

1. A speech synthesizer comprising:
a first storage unit configured to store n (n is an integer equal to or greater than 2) number of band noise signals obtained by applying each of n number of band-pass filters corresponding to n number of passing bands to a noise signal; a second storage unit configured to store n number of band pulse signals obtained by applying each of the band-pass filters to a pulse signal; a parameter input unit configured to input a fundamental frequency sequence of a speech to be synthesized, n number of band noise intensity sequences that show noise intensity of each of the passing bands, and a spectrum parameter sequence; an extraction unit configured to extract, for each samples of the speech to be synthesized, the band noise signal stored in the first storage unit by shifting the position in the band noise signal; an amplitude control unit configured to change, for each of the passing bands, an amplitude of the extracted band noise signal and the amplitude of the band pulse signal in accordance with the band noise intensity sequence of the passing band; a generation unit configured to generate, for the each pitch mark being created from the fundamental frequency sequence, a mixed sound source signal created by adding the band noise signal whose amplitude has been changed and the band pulse signal whose amplitude has been changed; a second generation unit configured to generate a mixed sound source signal for the speech from the mixed sound source signal for the each pitch mark; and a vocal tract filter unit configured to generate a speech waveform by applying a vocal tract filter, which uses the spectrum parameter sequence, to the generated mixed sound source signal.