Joint optimization of excitation and model parameters in parametric speech coders
AssigneeDoCoMo Communications Laboratories USA, Inc.
InventorsKhosrow Lashkari, Toshio Miki
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Abstract
A speech synthesis system is provided that optimizes a synthesis filter. Optimization is achieved by minimizing a synthesis error between the original speech sample and a synthesized speech sample. A gradient search algorithm in the root domain is also provided to aid minimization of the synthesis error.
Claims20
A speech synthesis system for encoding original speech comprising an excitation module responsive to an original speech sample and generating an excitation function;
- a synthesis filter responsive to said excitation function and said original speech sample and generating a synthesized speech sample;
- and a synthesis filter optimizer responsive to said excitation function and said synthesis filter and generating an optimized synthesized speech sample;
- wherein said synthesis filter optimizer minimizes a synthesis error between said original speech sample and said synthesized speech sample.
A method of generating a speech synthesis filter representative of a vocal tract comprising computing first coefficients of a speech synthesis polynomial using an original speech sample, thereby producing a first synthesized speech sample;
- converting said first coefficients of said polynomial to first roots;
- and computing second roots, thereby producing a second synthesized speech sample more representative of said original speech sample than said first synthesized speech sample.
A method for digitally encoding speech comprising means for producing an original speech sample, means for generating an excitation function;
- means for computing LPC polynomial coefficients, thereby producing a synthesized speech sample;
- means for optimizing said polynomial coefficients by minimizing a synthesis error between said original speech sample and said synthesized speech sample.
Dependencies are inferred from the claim text.