Voice activity detection
US5276765A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 28, 1992 |
| Grant date | Jan 4, 1994 |
| Priority date | — |
| Expiry date | Sep 28, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L25/00
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Voice activity detector (VAD) for use in an LPC coder in a mobile radio system uses autocorrelation coefficient R.sub.0, R.sub.1 . . . of the input signal, weighted and combined, to provide a measure M which depends on the power within that part of the spectrum containing no noise, which is thresholded against a variable threshold to provide a speech/no speech logic output. The measure is formula (I), where H.sub.i are the autocorrelation coefficients of the impulse response of an Nth order FIR inverse noise filter derived from LPC analysis of previous non-speech signal frames. Threshold adaption and coefficient update are controlled by a second VAD response to rate of spectral change between frames.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.