[jodrellblank]

Then again, my sensitivity is way too high. I can also feel whether my microwave is turned on through the wall!

Your microwave is a Faraday cage, it's not supposed to let microwaves leak out -> https://www.amazon.com/Microwave-Leak-Detector/s?k=Microwave... something like this might tell you if it's damaged.

A double blind test where you are deafened so you can't hear it, and don't know when it's on/off, would be interesting.