Circuit and method for the adaptive suppression of an acoustic feedback
US6611600B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 11, 1999 |
| Grant date | Aug 26, 2003 |
| Priority date | — |
| Expiry date | Jan 11, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R25/505
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A circuit for adaptive suppression of acoustic feedback forms part of a digital hearing aid, comprising a microphone (1), subtracter (3), hearing correcting means (4), receiver (6), delay element (9), filter (10), updating unit (11), lattice decorrelators (12, 13) and control unit (14). The transmission path is modeled with the feedback characteristic (7) and an adder (8). First decorrelator (12) decorrelates the echo-compensated input signal (en) and second decorrelator (13) decorrelates the delayed output signal (xn) by using coefficients (kn) from first decorrelator (12). The coefficients (kn) of the two filters (12, 13) are calculated by adaptive decorrelation of the echo-compensated input signal (en). This permit maximum convergence rates for minimum distortions. Updating of the filter coefficients mainly takes place where the greatest amplifications occur in the hearing correcting means (4). The fed-back signal components are continuously removed from the input signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.