Artificial intelligence pattern-recognition-based noise reduction system for speech processing
US5097510A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 7, 1989 |
| Grant date | Mar 17, 1992 |
| Priority date | — |
| Expiry date | Nov 7, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L21/0232
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A system is provided to reduce noise from a signal of speech that is contaminated by noise. The present system employs an artificial intelligence that is capable of deciding upon the adjustment of a filter subsystem by distinguishing between noise and speech in the spectrum of the incoming signal of speech plus noise. The system does this by testing the pattern of a power or envelope function of the frequency spectrum of the incoming signal. The system determines that the fast changing portions of that envelope denote speech whereas the residual is determined to be the frequency distribution of the noise power. This determination is done while examining either the whole spectrum, or frequency bands thereof, regardless of where the maximum of the spectrum lies. In another embodiment of the invention, a feedback loop is incorporated which provides incremental adjustments to the filter by employing a gradient search procedure to attempt to increase certain speech-like features in the system's output. The present system does not require consideration of minima of functions of the incoming signal or pauses in speech. Instead, the present system employs an artificial intelligence system …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.