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.

Date of Patent:
Apr. 03, 2001

Filed:

Jun. 30, 1998
Applicant:
Inventor:

Akhteruzzaman, Naperville, IL (US);

Assignee:

Lucent Technologies, Inc., Murray Hill, NJ (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04M 9/00 ;
U.S. Cl.
CPC ...
H04M 9/00 ;
Abstract

A telephone with an automatic muting circuit that mutes the microphone in response to detection of speaking pauses of the local user to reduce noise due to acoustical feedback that are detected by comparing the waveforms from the microphone and the audio speaker after being amplified by amplifiers with automatic gain control circuits to the same level with speech subtractor. During pauses when the signals compared are substantially the same, then automatic muting circuit is activated by the speech subtractor to mute the microphone but when the local user speaks into the microphone the subtraction of the waveforms does not yield a null result and the microphone is unmuted.


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