Digital speech sinusoidal vocoder with transmission of only subset of harmonics
US4771465A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 11, 1986 |
| Grant date | Sep 13, 1988 |
| Priority date | — |
| Expiry date | Sep 11, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L19/06
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A speech analyzer and synthesizer system using a sinusoidal encoding and decoding technique for voiced frames and noise excitation or multipulse excitation for unvoiced frames. For voiced frames, the analyzer transmits the pitch, values for a subset of offsets defining differences between harmonic frequencies and a fundamental frequency, total frame energy, and linear predictive coding, LPC, coefficients. The synthesizer is responsive to that information to determine the harmonic frequencies from the offset information for a subset of the harmonics and to determine the remaining harmonics from the fundamental frequency. The synthesizer then determines the phase for the fundamental frequency and harmonic frequencies and determines the amplitudes of the fundamental and harmonics using the total frame energy and the LPC coefficients. Once the phase and amplitudes have been determined for the fundamental and harmonic frequencies, the synthesizer performs a sinusoidal analysis. In another embodiment, the remaining harmonic frequencies are determined by calculating the theoretical harmonic frequencies for the remaining harmonic frequencies and grouping these theoretical frequencies into …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.