Speakerphone feedback attenuation
US8923530B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 10, 2009 |
| Grant date | Dec 30, 2014 |
| Priority date | — |
| Expiry date | Oct 31, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M1/62
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A method is disclosed for acoustic feedback attenuation at a telecommunications terminal. A speakerphone equipped with a loudspeaker and two microphones is featured. Signals from the two microphones are subjected to a calibration stage and then to a runtime stage. The purpose of the calibration stage is to match the microphones to each other by advantageously using both magnitude and phase equalization across the frequency spectrum of the microphones. During the runtime stage, the microphones monitor the ambient sounds received from sound sources, such as the speakerphone's users and the loudspeaker itself, during a conference call. The speakerphone applies the generated set of filter coefficients to the optimized microphone's signals. By combining the signal from the reference microphone with the filtered signal from the optimized microphone, the speakerphone is able to attenuate the sounds from the loudspeaker that would otherwise be transmitted back to other conference call participants.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.