I've recently put together an interesting idea that any transmitter could be a microphone. A sufficiently advanced eavesdropper could record the small variation

I've recently put together an interesting idea that any transmitter could be a microphone. A sufficiently advanced eavesdropper could record the small variation in the frequency transmitted due to the movement of the transmitter. I'm not sure if it's really possible, but sound has been reconstructed from video of the movement of leaves of plants or empty potato chip bags. Is it so strange that the signal from a transmitter might be carrying info you don't expect? Sound is such a strange beast. The keys you press on a keyboard can be reconstructed from audio because of differences in the sound of each key. Cryptographic keys can be reconstructed from the sound of a processor decrypting specially computed messages. I even read a theory about a bios worm that can infect nearby air-gapped computers via sound waves. Am I paranoid? Perhaps. Are these things possible? Perhaps.