Speech coding device for estimating an error of power envelopes of synthetic and input speech signals
US5905970A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 11, 1996 |
| Grant date | May 18, 1999 |
| Priority date | — |
| Expiry date | Dec 11, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L25/15
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In a speech coding device for coding an input speech with an AbS (Analysis by Synthesis) system and one of a forward type and a backward type configuration, a vocal tract prediction coefficient generating circuit produces a vocal tract prediction coefficient from one of an input speech signal and a locally reproduced synthetic speech signal. A speech synthesizing circuit produces a synthetic speech signal by using codes stored in an excitation codebook in one-to-one correspondence with indexes, and the vocal tract prediction coefficient. A comparing circuit compares the synthetic speech signal and input speech signal to thereby output an error signal. A perceptual weighting circuit weights the error signal to thereby output a perceptually weighted signal. A codebook index selecting circuit selects an optimal index for the excitation codebook out of at least the weighted signal, and feeds the optimal index to the excitation codebook. A power envelope estimating circuit produces power envelope signals from the synthetic speech signal and input speech signal, and compares the power envelope signals to thereby estimate an error signal representative of a difference between the envelope…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.