Waveform synthesis

A method of generating a synthetic voiced speech waveform, said method comprising:

• (a) storing data defining n-dimensional state space representations of voiced speech signals, n being an integer having a value of at least three, in which successive voiced speech pitch pulse cycles are superimposed to provide a model of voiced speech dynamics;
• (b) selecting a synthesized waveform starting point in said n-dimensional state space representation for a predetermined voiced speech waveform that is offset from said stored data by an offset vector;
• (c) selecting successive further synthesized waveform points in said n-dimensional state space representation for said predetermined voiced speech waveform that are also respectively offset from said stored data in dependence jointly upon the preceding point in the synthesized sequence, nearest other stored points in state sequence space and an offset vector therefrom;
• (d) repeating (b) and (c) for plural voiced speech pitch cycles;
• and
• (e) outputting the resulting sequence of thus synthesized waveform points to generate a voiced speech waveform.

A method of generating a synthetic voiced speech waveform, said method comprising:

• (a) storing data defining n-dimensional state space representations of plural voiced speech waveform portions, n being an integer having a value of at least three, in which successive voiced speech pitch pulse cycles are superimposed in n-dimensional state space to provide a model of voiced speech dynamics;
• (b) generating synthesized waveform points using said n-dimensional state space representation for a predetermined voiced speech waveform portion,
• (c) repeating (b) for plural successive different predetermined voiced speech waveform portions;
• and
• (d) outputting the resulting sequence of thus synthesized waveform points to generate a voiced speech waveform.

Synthesis apparatus comprising:

• (a) means for generating a cyclical sound waveform sample;
• (b) means for generating a successive cyclical sound waveform sample from said cyclical sound waveform sample and transformation data, wherein said transformation data comprise data defining the evolution of said cycles in a temporal vicinity of said cyclical sound waveform and the change in shape of said cycles in said temporal vicinity from cycle to cycle;
• (c) means for designating said successive cyclical sound waveform sample as a cyclical sound waveform sample and repeating (b);
• (d) means for repeating (c) a plurality of times to generate a sequence of said successive cyclical sound waveform samples corresponding to a plurality of said cycles;
• and
• (e) means for outputting the samples of said sequence to generate a waveform representing a cyclical sound.

A method of generating a cyclical sound waveform corresponding to a sequence of substantially similar cycles, said method comprising:

• (a) generating a first instantaneous value of the amplitude of a cyclical sound waveform;
• (b) generating a second instantaneous value of the amplitude of a cyclical sound waveform from said first instantaneous value and transformation data, wherein said transformation data comprise data defining the evolution of said cycles in the temporal vicinity of said cyclical sound waveform and the change in shape of said cycles in said temporal vicinity from cycle to cycle;
• (c) designating said second instantaneous value as a first instantaneous value and repeating (b);
• (d) repeating (c) a plurality of times to generate a sequence of said instantaneous values corresponding to a plurality of said cycles;
• and
• (e) outputting the instantaneous values of said sequence to generate a waveform representing a cyclical sound.

Synthesis apparatus comprising:

• (a) means for generating a first instantaneous value of the amplitude of a cyclical sound waveform;
• (b) generating a second instantaneous value of the amplitude of a cyclical sound waveform from said first instantaneous value and transformation data, wherein said transformation data comprise data defining the evolution of said cycles in the temporal vicinity of said cyclical sound waveform and the change in shape of said cycles in said temporal vicinity from cycle to cycle;
• (c) designating said second instantaneous value as a first instantaneous value and repeating (b);
• (d) means for repeating (c) a plurality of times to generate a sequence of said instantaneous values corresponding to a plurality of said cycles;
• and
• (e) outputting the instantaneous values of said sequence to generate a waveform representing a cyclical sound.