Comfort noise generator using modified Doblinger noise estimate
US7649988B2 · kind B2 · utility
15Cited by
5References
10Claims
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Key dates
| Filing date | Jun 15, 2004 |
| Grant date | Jan 19, 2010 |
| Priority date | — |
| Expiry date | Mar 5, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L19/012
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A background noise estimate based upon a modified Doblinger noise estimate is used for modulating the output of a pseudo-random phase spectrum generator to produce the comfort noise. The circuit for estimating noise includes a smoothing filter having a slower time constant for updating the noise estimate during noise than during speech. Comfort noise is smoothly inserted by basing the amount of comfort noise on the amount of noise suppression. A discrete inverse Fourier transform converts the comfort noise back to the time domain and overlapping windows eliminate artifacts that may have been produced during processing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.