4 ms·

Forgive me, as someone with zero actual knowledge in this field. This may be a naive question, but wouldn't this be fairly easily defeated by playing songs in t

Forgive me, as someone with zero actual knowledge in this field. This may be a naive question, but wouldn't this be fairly easily defeated by playing songs in the background?

justwalt 8y ago
I think that would just add music to the sound recovered.
nikanj 8y ago
A fan would probably work too, as it adds more white noise to the already noisy signal
- seandougall 8y ago
  And might blow the chip bag away entirely :)
mvid 8y ago
It might be possible to cancel that noise out. But something like a pink noise generator or an office grey noise generator would probably fool it, the same way it would fool a microphone at distance
- joewee 8y ago
  This doesn’t work anymore, if it ever did. There is free software capable of isolating audio like a single voice from background noise.
  - grkvlt 8y ago
    Not sure how this can't work, it's just audio jamming, same as for EM waves. You just need to broadcast sufficient noise to cover the signal, i.e. the S:N ratio is such that the receiver (crisp packet, microphone, etc.) can no longer see the signal above the noise floor. Now, this might mean broadcasting a loud noise signal, which could overwhelm your (or other friendly) receivers (ears, etc.) so optimal placement of the jamming noise source becomes an issue. Generally, you want it closer to the threat than you, so that distance attenuation keeps it bearable for you but still jams possible recording devices. Or, introduce high bandwidth noise vibrations into the surfaces of the area you are in, such as windows or walls. Anyway, it's very possible and in use today in secure facilities that must be protected from audio eavesdropping.
mygo 8y ago
you can separate the music from the other sounds.
angry_octet 8y ago
You could identify the song and then subtract it. If you add which noise it raises the noise floor, but won't effect overall decoding that much, because there is such deep knowledge of which phonemes are likely to follow in a given sequence. You have to assume there is a model trained for each participant, e.g. using telephone intercepts, other listening devices. Maybe if you simultaneously played back segments of dozens of conversations of the participants talking. That would certainly be confusing for the participants.
ChuckMcM 8y ago
Yes, or even better moderate white noise. Ambient sound will lower the signal to noise ratio between ambient audio and the audio of interest and so essentially render using this to eavesdrop on someone effectively moot. As an exercise in using tertiary effects to pull in signals you might otherwise be prevented from receiving, well that is pretty cool.
Digit-Al 8y ago
Thanks for the replies everyone. A follow up: would the sound recovered from such vibrations have enough resolution to perform some of the tricks described (isolating voice from background noise or identifying the song and cancelling it out, etc...)?

Forgive me, as someone with zero actual knowledge in this field. This may be a naive question, but wouldn't this be fairly easily defeated by playing songs in the background?

justwalt 8y ago

I think that would just add music to the sound recovered.

nikanj 8y ago

A fan would probably work too, as it adds more white noise to the already noisy signal

seandougall 8y ago
And might blow the chip bag away entirely :)

mvid 8y ago

It might be possible to cancel that noise out. But something like a pink noise generator or an office grey noise generator would probably fool it, the same way it would fool a microphone at distance

joewee 8y ago
This doesn’t work anymore, if it ever did. There is free software capable of isolating audio like a single voice from background noise.
- grkvlt 8y ago
  Not sure how this can't work, it's just audio jamming, same as for EM waves. You just need to broadcast sufficient noise to cover the signal, i.e. the S:N ratio is such that the receiver (crisp packet, microphone, etc.) can no longer see the signal above the noise floor. Now, this might mean broadcasting a loud noise signal, which could overwhelm your (or other friendly) receivers (ears, etc.) so optimal placement of the jamming noise source becomes an issue. Generally, you want it closer to the threat than you, so that distance attenuation keeps it bearable for you but still jams possible recording devices. Or, introduce high bandwidth noise vibrations into the surfaces of the area you are in, such as windows or walls. Anyway, it's very possible and in use today in secure facilities that must be protected from audio eavesdropping.

mygo 8y ago

you can separate the music from the other sounds.

angry_octet 8y ago

You could identify the song and then subtract it. If you add which noise it raises the noise floor, but won't effect overall decoding that much, because there is such deep knowledge of which phonemes are likely to follow in a given sequence. You have to assume there is a model trained for each participant, e.g. using telephone intercepts, other listening devices. Maybe if you simultaneously played back segments of dozens of conversations of the participants talking. That would certainly be confusing for the participants.

ChuckMcM 8y ago

Yes, or even better moderate white noise. Ambient sound will lower the signal to noise ratio between ambient audio and the audio of interest and so essentially render using this to eavesdrop on someone effectively moot. As an exercise in using tertiary effects to pull in signals you might otherwise be prevented from receiving, well that is pretty cool.

Digit-Al 8y ago

Thanks for the replies everyone. A follow up: would the sound recovered from such vibrations have enough resolution to perform some of the tricks described (isolating voice from background noise or identifying the song and cancelling it out, etc...)?