Removal of swirl artifacts from celp-based speech coders
US5633982A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 21, 1996 |
| Grant date | May 27, 1997 |
| Priority date | — |
| Expiry date | Oct 21, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L2021/02168
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The perception of speech processed by a CELP based coder, such as a VSELP coder, when operating in noisy background conditions is improved by removing swirl artifacts during silence periods. This is done by removing the low frequency components of the input signal when no speech is detected. A speech activity detector distinguishes between a periodic signal, like speech, and a non-periodic signal, like noise by using most of the VSELP coder internal parameters to determine the speech or non-speech conditions. To prevent the VSELP coder from determining pitches for non-periodic signals, a high pass filter is applied to the input signal to remove the pitch information for which the VSELP coder searches.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.