[127001brewer]

This is also talked about in the book, "Silence on the Wire".

http://www.amazon.com/Silence-Wire-Passive-Reconnaissance-In...

[parktheredcar]

Thanks for sharing, that looks like an interesting read.

There was also this paper (linking to summary) about figuring out how to decode the audio of someone typing on a keyboard.

https://freedom-to-tinker.com/blog/felten/acoustic-snooping-...

[127001brewer]

...it's actually a good compliment while (slowly) trying to complete the challenges on http://cryptopals.com/