Noise canceling apparatus
US4769847A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 30, 1986 |
| Grant date | Sep 6, 1988 |
| Priority date | — |
| Expiry date | Oct 30, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H21/0012
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
In order to eliminate background noise infiltrating into an input audio signal, a noise-canceling apparatus includes: first and second acoustic pickups for primarily picking up the audio signal and noise, respectively; a filter receiving the output of the second acoustic pickup; a subtracter for subtracting the output of the filter, when the audio signal is silent, from the output of the first acoustic pickup; and a coefficient determination for determining coefficients of the filter so as to make the filter generate a noise signal corresponding to a signal generated by passing the noise through a transmission path having a transmission frequency characteristic from the noise source to the first acoustic pickup. The coefficients of the filter are determined on the basis of mutual-correlation coefficients between the outputs of the first and second pickups and self-correlation coefficients of the output of the second pickup, thereby improving the processing efficiency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.