Feedback cancellation apparatus and methods utilizing adaptive reference filter mechanisms
US6434247B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 30, 1999 |
| Grant date | Aug 13, 2002 |
| Priority date | — |
| Expiry date | Jul 30, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R25/453
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A feedback cancellation system for a hearing aid or the like adapts a first filter in the feedback path that models the quickly varying portion of the hearing aid feedback path, and adapts a second filter in the feedback path that is used either as a reference filter for constrained adaptation or to model more slowly varying portions of the feedback path. The second filter is updated only when the hearing aid signals indicate that an accurate estimate of the feedback path can be obtained. Changes in the second filter are then monitored to detect changes in the hearing aid feedback path. The first filter is adaptively updated at least when the condition of the signal indicates that an accurate estimate of physical feedback cannot be made. It may be updated on a continuous or frequent basis.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.