Telephone with automatic pause responsive, noise reduction muting and method
AssigneeLucent Technologies Inc.
InventorAkhteruzzaman
Life of this patent
Estimating the term…
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.
Claims17
In a telephone having a microphone and an audio speaker, the improvement being an automatic muting circuit, comprising:
- means for detecting pauses in speaking of a local user, in which the means for detecting pauses include a signal comparator to compare signals from the microphone and the audio speaker;
- and
- means responsive to the detecting means for automatically muting the microphone.
In a telephone having a microphone and an audio speaker, the improvement being an automatic muting method, comprising the steps of:
- detecting pauses in speaking of a local user;
- comparing waveforms of the signals from the microphone and from the audio speaker;
- and
- responding to the detection of the speaking pauses by automatically muting the microphone.
Dependencies are inferred from the claim text.