Noise reduction
US9142221B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 7, 2008 |
| Grant date | Sep 22, 2015 |
| Priority date | — |
| Expiry date | Nov 9, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L2021/02163
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A signal processor for estimating noise power in an audio signal includes a filter unit for generating a series of power values, each power value representing the power in the audio signal at a respective one of a plurality of frequency bands; a signal classification unit for analysing successive portions of the audio signal to assess whether each portion contains features characteristic of speech, and for classifying each portion in dependence on that analysis; a correction unit for estimating a minimum power value in a time-limited part of the audio signal, estimating the total noise power in that part of the audio signal and forming a correction factor dependent on the ratio of the minimum power value to the estimated total noise power, the correction unit being configured to estimate the minimum power value and the total noise power over only those portions of the time-limited part of the signal that are classified by the signal classification unit as being less characteristic of speech; and a noise estimation unit for estimating noise in the audio signal in dependence on the power values output by the filter unit and the correction factor formed by the correction unit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.