Waveform synthesis
AssigneeBritish Telecommunications plc
InventorsSTEPHEN MCLAUGHLIN, MICHAEL BANBROOK
Life of this patent
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Abstract
A method of synthesis of a voiced speech sound comprising calculating each new output value from the previous output value using data modelling the evolution, over a short time interval, of the voiced speech sound to be synthesised.
Claims15
A method of generating a synthetic waveform output corresponding to a sequence of substantially similar cycles, comprising the steps of
- (a) generating a synthetic waveform sample;
- (b) generating a successive waveform sample from said synthetic waveform sample and data defining the transformation followed by said cycles in the temporal vicinity of said synthetic waveform sample;
- (c) designating said successive waveform sample as a synthetic waveform sample and repeating step (b);
- (d) repeating step (c) a plurality of times to generate a sequence of said successive waveform samples corresponding to a plurality of said cycles;
- and
- (e) outputting the samples of said sequence to generate a waveform.
A method according to any preceding claim, in which said steps (a) and (b) comprise generating a plurality of values representing said waveform sample values as a point in a multidimensional space in which corresponding portions of successive said cycles are substantially superposed.
A method according to any preceding claim, in which said step (b) comprises calculating said transformation from a set of stored waveform values.
A method according to any preceding claim in which the initial performance of said step (a) to initial synthesis of said waveform comprises a step of selection of an initial value which differs from a previous initial value selected on a previous synthesis of said waveform.
A method of synthesis of a voiced speech sound comprising calculating each new output value from the previous output value using data modelling the evolution, over a short time interval, of the voiced speech sound to be synthesised.
A method of concatenating two cyclical sounds, comprising progressively interpolating between pairs of values of said sounds at corresponding points within the cycle of each of said sounds.
A method of synthesising a cyclical sound intermediate between two other cyclical sounds, for each of which a succession of sample values corresponding to a plurality of cycles are stored, comprising the steps of generating interpolated waveform samples consisting of a succession of values each of which is interpolated from a pair of points, one each respectively from corresponding portions from a cycle of each of the stored waveforms;
- generating a model of the evolution, over a short time interval, of the interpolated waveform;
- and calculating each successive output value from a previous output value using said evolution model.
Synthesis apparatus arranged to perform the method of any preceding claim.
Dependencies are inferred from the claim text.