I’m curious, how many people are aware of these sounds. I have designed, etched, and built my own switching power supplies along with winding my own transformers. I am aware of the source of the noise. So, does anyone else hear these high frequency sounds regularly?
Objective tinnitus is a thing, though less common than subjective tinnitus. It is possible your ear actually is producing sound others can hear, though I guess only with a stethoscope, not the naked ear. https://nyulangone.org/conditions/tinnitus/types