Method and apparatus for providing background acoustic noise during a discontinued/reduced rate transmission mode of a voice transmission system
US6782361B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 3, 2000 |
| Grant date | Aug 24, 2004 |
| Priority date | — |
| Expiry date | Mar 3, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L19/012
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Natural-quality synthetic noise will replace background acoustic noise during speech gaps and will achieve a better representation of the excitation signal in a noise-synthesis model by classifying the type of acoustic environment noise into one or more of a plurality of noise classes. The noise class information is used to synthesize background noise that sounds similar to the actual background noise during speech transmission. In some embodiments, the noise class information is derived by the transmitter and transmitted to the receiver which selects corresponding excitation vectors and filters them using a synthesis filter to construct the synthetic noise. In other embodiments, the receiver itself classifies the background noise present in hangover frames and uses the class information as before to generate the synthetic noise. The improvement in the quality of synthesized noise during speech gaps helps to preserve noise continuity between talk spurts and speech pauses, and enhances the perceived quality of a conversation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.