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I am currently using FFT / other spectral analysis algorithms in order to analyse sound from the iphone's

microphone. However, if the user taps the device while recording, I get unexpected results. Is there a

filter I can implement on the raw sound data to remove the tap disturbances.

Thank You,

nonono

edit: perhaps something to do with accelerometer data

123hal321
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    Of course not - if you tap a microphone you'll get a large amount of somewhat random noise which will tend to swamp the signal of interest. This is not an unexpected result. – Paul R Mar 13 '11 at 21:02
  • Not even via combiation with accelerometer data? – 123hal321 Mar 13 '11 at 21:07
  • nope - next time you'r talking to someone on the phone, ask them to tap the microphone while they are talking to you, and then think about how you would remove that noise programatically. – Paul R Mar 13 '11 at 22:56

1 Answers1

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Sound from tapping on something containing a microphone would seem to be completely expected.

If you aren't interested in an analysis of the expected tap sounds, you could always completely stop analyzing audio if the accelerometer indicates any motion above some tiny threshold, and start analyzing again a second or two after all acceleration stops.

If you need to tap on the UI while not interfering with some other audio, a microphone on an isolating stand plugged into the headset jack might help.

hotpaw2
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