Takashi Aso

Method and apparatus for speech analysis and synthesis by sampling a power spectrum of input speech

A method for speech analysis and synthesis for obtaining synthesized speech of a high quality includes the steps of determining a short-period power spectrum by performing an FFT operation on a speech wave, sampling the spectrum at the positions corresponding to the multiples of a basic frequency, applying a cosine polynomial model to the thus obtained sample points to determine the spectrum envelope thereat, then calculating the mel cepstrum coefficients from the spectrum envelope, and effecting speech synthesis, utilizing the mel cepstrum coefficients as the filter coefficients in a synthesizing (logarithmic mel spectrum approximation) filter.

Speech synthesis apparatus and method for synthesizing speech from a character series comprising a text and pitch information

A speech synthesis method and apparatus for synthesizing speech from a character series comprising a text and pitch information. The apparatus includes a parameter generator for generating power spectrum envelopes as parameters of a speech waveform to be synthesized representing the input text in accordance with the input character series. The apparatus also includes a pitch waveform generator for generating pitch waveforms whose period equals the pitch specified by the pitch information. The pitch waveform generator generates the pitch waveforms from the input pitch information and the power spectrum envelopes generated by the parameter generator. Also provided is a speech waveform output device for outputting the speech waveform obtained by connecting the generated pitch waveforms.

Method and apparatus for speech processing

An apparatus and method for processing vocal information includes an extractor for extracting a plurality of spectrum information from parameters for vocal information, a vector quantizer for vector-quantizing the extracted spectrum information and for producing a plurality of parameter patterns therefrom, a memory for storing the plurality of parameter patterns so obtained, and a memory for storing positional information indicating the positions at which the plurality of parameter patterns are stored and for storing code information specifying parameter patterns and corresponding to the positional information. The parameter patterns and code information can be used to synthesize speech. Because a small number of parameter patterns are used, only a small memory capacity is needed and efficient processing of vocal information can be performed.

Speech synthesizer and method for synthesizing speech for superposing and adding a waveform onto a waveform obtained by delaying a previously obtained waveform

A speech synthesizer includes a first indicator for indicating the amplitude of a waveform by using a random number, a second indicator for indicating the superposition period for waveforms by using a random number, a waveform generator for generating first and second waveforms having an amplitude indicated by the first indicator, and a waveform superposition device for synthesizing an unvoiced speech waveform by superposing the second waveform generated by the waveform generator onto a waveform obtained by delaying the first waveform by a superposition period indicated by the second indication means. The speech synthesizer is capable of making the frequency characteristic of unvoiced speech analogous to that of white noise, and generating synthesized speech which is natural and analogous to an actual human voice.

Speech information processing method and apparatus connectable to a public line

An apparatus for positively recognizing speech generated by a large, unspecified number of speakers performs optimal speech recognition processing on the basis of speech information dictionaries corresponding to the respective speakers by consecutively inputting and preparing in advance speech information dictionaries corresponding to the respective speakers.