Echo Cancellation Software

Discussion in 'Digital Audio' started by niallabrown, Oct 28, 2007.

  1. niallabrown macrumors newbie

    Oct 28, 2007
    I need to monitor the sound coming from my internal mic on a powerbook. This of course results in feedback. Is there Mac software that can cancel this echo, similar to the echo cancellation in Skype or MSN voice chat but for all sounds being processed?

    The idea is that individuals who have vision and hearing loss at the same time can touch the speaker to feel the sounds around the room picked up by the very sensitive powerbook mic.

    Thanks very much,

  2. CanadaRAM macrumors G5


    Oct 11, 2004
    On the Left Coast - Victoria BC Canada
    Feedback suppression is tricky. The first and most obvious thing is to stop the sound from the speakers reaching the microphone. This is done by reducing speaker volume, physical positioning of the speakers, and/or some form of physical baffling between the speaker and the mic. All are difficult to do on a laptop. Other than maybe having a little 'mouse house' covering the speaker that one could put their finger inside.

    Then, you can use equalization to cut the frequencies that are feeding back the soonest.

    Lastly, you can try delaying the speaker output a small amount, so that the feedback would usually not happen while the original sound was still peaking. Or, since frequency accuracy may not be critical in this application, you could try pitch shifting the frequencies down, so they did not reinforce.

    The best solution overall, though, would be to use external speakers which could be set at a distance from the mic, and could be selected for their directionality and baffling.
  3. niallabrown thread starter macrumors newbie

    Oct 28, 2007

    Thanks, good suggestions. I think the delay is the one that would work but I'm not sure how to create that delay. Any suggestions on how to do that?

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