Voice activity detector
US5749067A · kind A · utility
60Cited by
11References
18Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 8, 1996 |
| Grant date | May 5, 1998 |
| Priority date | — |
| Expiry date | Mar 8, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M19/08
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Speech is distinguished from noise by a spectral comparison of an input signal with a stored noise estimate. Updating of the noise estimate stored in a buffer is permitted during periods when speech is absent under control of an auxiliary detector. In order to improve operation in the presence of signals with strong harmonic components, e.g., signalling tones, an LPC prediction gain is computed from the input (x(i)) and a residual (y(i)) obtained from the input following filtering by a filter having a response complementary to the frequency spectrum of the input, and if the gain exceeds a threshold, buffer updating is suppressed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.