Noise canceling system
US4723294A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 8, 1986 |
| Grant date | Feb 2, 1988 |
| Priority date | — |
| Expiry date | Dec 8, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R3/005
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Under the condition where a plurality of background noise sources exists, there are arranged a first receiver, primarily receiving desired voice, and a plurality of second receivers each primarily receiving noise from a corresponding noise source. Filter coefficients of equivalent noise-producing filters, each having a frequency transmission characteristic equivalent to that of transmission path from its corresponding noise source to the first receiver, are estimated based upon mutual-correlation coefficients among the outputs of the first and second receivers and auto-correlation coefficients of the respective outputs of the second receivers. The noise signals from the equivalent noise-producing filters are subtracted from the output of the first receiver, thereby canceling the background noise. The filter coefficients estimation may be performed by using a maximum of the mutual-correlation coefficients between the outputs of the first receiver and the respective second receivers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.