Communication system tonal component maintenance techniques
US8031861B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 26, 2008 |
| Grant date | Oct 4, 2011 |
| Priority date | — |
| Expiry date | Jun 1, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L25/18
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An apparatus and method for suppressing noise is presented. The apparatus may utilize a filter bank of bandpass filters to split the input noisy speech-containing signal into separate frequency bands. To determine whether the input signal contains speech, DTMF tones or silence, a joint voice activity & DTMF activity detector (JVADAD) may be used. The overall average noise-to-signal ratio (NSR) of the input signal is estimated in the overall NSR estimator, which estimates the average noisy signal power in the input signal during speech activity and the average noise power during silence. Two indirect power measures are performed for each band, measuring a short-term power and a long-term power. The power estimation processes are adapted based on the signal activity indicated by the JVADAD. A NSR adapter adapts the NSR for each frequency band based on the long-term and short-term power measures, the overall NSR and the signal activity indicated by the JVADAD. The NSR adaptation may then be performed. The gain computer utilizes these NSR values to determine the gain factors for each frequency band. The gain multiplier may then perform the attenuation of each frequency band. Finally, t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.