Method and apparatus for adaptive audio resonant frequency filtering
US5245665A · kind A · utility
41Cited by
17References
53Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 12, 1991 |
| Grant date | Sep 14, 1993 |
| Priority date | — |
| Expiry date | Jun 12, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R3/02
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Audio signals are digitized and an FFT is conducted on samples of the digitized signals to produce corresponding frequency spectrums. These spectrums are analyzed, such as by determining one or more peak frequency magnitudes which are 33 dB greater than harmonics or subharmonics of the frequency in a plurality of several successive spectrums, to detect resonating feedback frequencies. The offending frequency is then filtered in the time domain, either in the digitized form or analog form, to eliminate the feedback.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.