Acoustic coupling compensation for a speakerphone of a system
US6459942B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 1997 |
| Grant date | Oct 1, 2002 |
| Priority date | — |
| Expiry date | Sep 30, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M9/082
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A speakerphone of a system with a digital signal processor, such as a computer, uses a filter set or network to provide acoustic coupling loss at a microphone to offset acoustic coupling gain produced by sound reflections resulting from various conditions in the system. The filter network processes an acoustic signal before the signal is provided to a digital signal processor to eliminate acoustic coupling gain that the digital signal processor is unable to cancel or offset. The filter network detects when the acoustic coupling gain in the acoustic signal at the microphone exceeds the maximum amount of acoustic coupling loss supplied by the digital signal processor. Alternatively, if acoustic coupling gain is desirable at the frequency location of the anomaly caused by the sound reflections, the filter network is used to boost the acoustic coupling gain produced by the anomaly. Thus, the present speakerphone uses equalization at the microphone to boost or attenuate acoustic coupling gain caused by frequency anomalies before acoustic echo cancellation by the digital signal processor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.