Noise reduction method and device using two pass filtering
US7313518B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 19, 2001 |
| Grant date | Dec 25, 2007 |
| Priority date | — |
| Expiry date | Apr 27, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L21/0208
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The device calculates a first frequency-dependent useful signal level estimator for the frame. The transfer function of a first noise-reducing filter is determined on the basis of the first useful signal level estimator and of a frequency-dependent noise level estimator. A second frequency-dependent useful signal level estimator for the frame is then calculated by combining the spectrum of the input signal and the transfer function of the first noise-reducing filter. The transfer function of a second noise-reducing filter is determined on the basis of the second useful signal level estimator and of the noise level estimator. The latter transfer function is used in a frame filtering operation to produce a signal with reduced noise.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.