Method of and means for adaptively filtering near-stationary noise from speech
US4025721A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 4, 1976 |
| Grant date | May 24, 1977 |
| Priority date | — |
| Expiry date | May 4, 1996 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R25/453
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
By identifying and analyzing the properties of the parameters of an input signal that contains speech in the presence of simultaneously occuring near-stationary noise, pauses between speech intervals as well as the termination of such noise can be recognized. When a pause interval containing noise is recognized, the parameters identified during such interval are used to set the parameters of an adaptive filter through which the input signal is passed during subsequent intervals of speech and until the noise terminates. During the time the input signal passes through the filter, the near-stationary noise is filtered out. In response to recognition of the termination of noise, the input signal is caused to by-pass the filter which is then prepared to accept the parameters of noise occuring in a subsequent pause.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.