3 ms·

A white noise generator placed over the microphone, perhaps?

• nitrogen 10y ago
  White noise can be filtered out if it's not louder than the source sound within the frequency bands of interest over the time interval that matters for interpreting speech. So make sure it's loud, and maybe contour the noise to match the frequency distribution of speech, and maybe make it unpredictably variable over time.
  • DashRattlesnake 10y ago
    But wouldn't it only have to be loud at the microphone? So a quiet but very close white noise source (e.g. something taped directly over the microphone) could mask a louder but more distant source?
  • filoeleven 10y ago
    One neat idea from Neal Stephenson's Anathem (with likely analogues elsewhere) is essentially a chatterbox that records people speaking in a conversation, chops up the audio into syllables, and plays those back at random to foil eavesdroppers. This might work better than white noise, assuming you trust the computer that's doing the scrambling!