Feedback cancellation with low frequency input
US7340063B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 7, 2000 |
| Grant date | Mar 4, 2008 |
| Priority date | — |
| Expiry date | Sep 8, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R25/453
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The invention relates to a method for canceling feedback in an acoustic system comprising a microphone, a signal path, a speaker and means for detecting presence of feedback between the speaker and the microphone, the method comprising providing a LMS algorithm for processing the signal; where the LMS algorithm operates with a predetermined adaptation speed when feedback is not present; where the LMS algorithm operates an adaptation speed faster than the predetermined adaptation speed when feedback is present, and where the means for detecting the presence of feedback is used to control the adaptation speed selection of the LMS algorithm. The invention further relates to a method comprising using a highpass filter to prevent low-frequency signals from entering the LMS algorithm. The invention still further relates to a method comprising using bandwidth detection means for determining the presence of a feedback signal. The invention also relates to hearing aids for implementing these methods.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.