Method to reduce acoustic coupling in audio conferencing systems
View Patent ↗A method to reduce acoustic coupling in an audio conferencing system having a loudspeaker and a plurality of microphones, comprising detecting the presence of one of either a source of near-end signal or a source of far-end signal source relative to the audio conferencing system, and in the event of detecting a source of near-end signal then processing the near-end signal with high directivity towards the near-end source, and in the event of detecting a source of far-end signal or double-talk then processing the far-end signal with high coupling characteristics between the loudspeaker and microphones.
1. A method to reduce acoustic coupling in a full-duplex audio conferencing system having a loudspeaker signal and a plurality of microphones, the method comprising:
detecting the presence of one of either a near-end speech or a far-end speech by full-duplex acoustic echo cancellation control logic;
in the event of detecting the near-end speech, employing a first beamformer to process the near-end speech, the first beamformer designed with good directivity towards the near-end speech; and
in the event of detecting the far-end speech, employing a second beamformer to process the far-end speech, the second beamformer designed to place a null in a direction of the loudspeaker signal.
2. method of claim 1 , further including gradually switching between the first and second beamformers.
3. The method of claim 1 , further comprising detecting the presence of double-talk and employing the second beamformer to process the far-end speech.
4. The method of claim 1 , wherein the first and second beamformers are designed to provide similar gain and frequency response towards the near-end speech.
5. A full-duplex audio conferencing system comprising:
a loudspeaker configured to acoustically transmit a signal comprising a far-end speech;
a plurality of microphones configured to acoustically receive a near-end speech;
a full-duplex acoustic echo canceller configured to detect the presence of one of either the near-end speech or the far-end speech;
a first beamformer to process the near-end speech and configured to have good directivity towards the near-end speech; and
a second beamformer to process the far-end speech and configured to place a null in the direction of the loudspeaker signal,
wherein, a switch occurs between the first and second beamformers depending upon which speech is detected.
6. The system of claim 5 , wherein the switch occurs gradually.
7. The system of claim 5 , wherein the first and second beamformers are designed to provide similar gain and frequency response towards the near-end speech.
8. The system of claim 5 , wherein the echo canceller is further configured to detect the presence of double-talk and the second beamformer is used.
9. A method to reduce acoustic coupling in a full-duplex audio conferencing system having a loudspeaker signal and a plurality of microphones, the method comprising:
detecting the presence of one of either a near-end speech or a far-end speech by full-duplex acoustic echo cancellation control logic;
in the event of detecting the near-end speech, employing a first beamformer to process the near-end speech, the first beamformer adapted for spatial directivity in the direction of near-end speech; and
in the event of detecting the far-end speech, employing a second beamformer to process the far-end speech, the second beamformer adapted to provide strong attenuation of the loudspeaker signal.