Make that "every vibrating surface can be a potential microphone ..."
replyThe laser on a hotel window experiment comes to mind.
replyOr an adapted Theremin
replywith a high speed camera any vibrating reflective object like a potato chips bag can become a weak microphone if you have line of sight even behind a soundproof window:
https://www.youtube.com/watch?v=FKXOucXB4a8
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