Modulated microwaves could. There are reports of random metal items suddenly playing local high-powered radio stations, and modulated/pulsed microwaves can caus

Modulated microwaves could. There are reports of random metal items suddenly playing local high-powered radio stations, and modulated/pulsed microwaves can cause https://en.wikipedia.org/wiki/Microwave_auditory_effect https://en.wikipedia.org/wiki/Microwave_auditory_effect Note that the purpose of the microwaves doesn't have to be frying someone's brain or creating sound; it can be some unrelated attempt to e.g. try to intercept data think about possible attempts to use preexisting materials in a way similar to https://en.wikipedia.org/wiki/The_Thing_(listening_device) https://en.wikipedia.org/wiki/The_Thing_(listening_device)