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Detection and suppression of returned audio at near-end

A near-end, audio technology used in echo suppressors/cancellers, interconnects, two-way PA telephone systems, etc.

Active Publication Date: 2011-04-20
POLYCOM INC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Therefore, near-end echo cancellation may benefit the person at the far end, but it does nothing to prevent the near-end from hearing the near-end audio being returned from the far end as an echo

Method used

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  • Detection and suppression of returned audio at near-end
  • Detection and suppression of returned audio at near-end
  • Detection and suppression of returned audio at near-end

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0014] A. Proximal unit with echo detection and suppression

[0015] figure 2 The near-end unit 10 shown schematically in can be used for teleconferencing or video conferencing. As previously mentioned, near-end unit 10 has audio decoder 12, audio encoder 14, speaker 20, and microphone 40, and is communicatively coupled to remote unit 16 using methods known in the art. During a conference, audio decoder 12 receives far-end audio, decodes it, and sends the decoded audio to speaker 20 for near-end participants to hear. Accordingly, microphone 40 picks up near-end audio from the participant, and audio encoder 14 encodes the near-end audio and sends it to far-end unit 16 .

[0016] In order to reduce the influence of the acoustic coupling (shown as arrow 11) at the near end, the near end unit 10 has a near end echo canceller 30, and the near end echo canceller 30 subtracts the noise that has been picked up by the near end microphone 40 through the acoustic coupling. Audio emitt...

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PUM

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Abstract

Audio from a near-end that has been acoustically coupled at the far-end and returned to the near-end unit is detected and suppressed at the near-end of a conference. First and second energy outputs for separate bands are determined for the near-end audio being sent from the near-end unit and for the far-end audio being received at the near-end unit. The near-end unit compares the first and second energy outputs to one another for each of the bands over a time delay range and detects the return of the sent near-end audio in the received far-end audio based on the comparison. The comparison can use a cross-correlation to find an estimated time delay used for further analysis of the near and far-end energies. The near-end unit suppresses any detected return by muting or reducing what far-end audio is output at its loudspeaker.

Description

technical field [0001] The present disclosure relates to conferencing systems, and more particularly to the detection and suppression of return audio at the near end. Background technique [0002] During a conference, at least two communication systems (ie, a near-end unit and a remote unit) participate in a call. Typically, these units have near-end echo cancellation. For example, a near-end unit 10 shown schematically in FIG. 1 has an audio decoder 12, an audio encoder 14, a speaker 20, and a microphone 40, and is communicatively coupled to a remote unit 16 using methods known in the art. During a conference, audio decoder 12 receives far-end audio, decodes it, and sends the decoded audio to speaker 20 so that near-end participants can hear it. Accordingly, microphone 40 picks up near-end audio from the participant, and audio encoder 14 encodes the near-end audio and sends it to far-end unit 16 . Due to the proximity of speaker 20 and microphone 40 , acoustic coupling (...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04M9/08H04M3/56
CPCH04M3/002H04M1/6033H04M9/085H04M3/2236H04M3/568
Inventor P·L·楚W·邓拉普
Owner POLYCOM INC
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