The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 01, 2002
Filed:
Sep. 30, 1997
Compaq Information Technologies Group, L.P., Houston, TX (US);
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.