Preamble: At 5 AM in the morning, if I sit quietly and listen attentively, I can hear many different noises, on a very high frequency. If I try to isolate the ones that are less noisy, I can clearly distinguish some "notes", which have a fixed frequency (pitch) but are also intermittent. Of course, this is no rigorous experiment, but I tried to get closer to electronic objects and the intensity of this sound increased. This made me think of a questions that I think many of us have thought about, at some point or another.
Do electromagnetic waves, like Wi-Fi and mobile phone signals, interact with air in such a way that could produce an hearable sound? If so, would this sound be at a determined frequency, and how would this be related to the frequency of the electromagnetic wave?