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?
I can’t of anything that makes an unwanted sound. Old CRT TVs used to, but I haven’t used one in years. My monitor at work makes a sound when it turns on or off (I believe there’s an ass-old fuse in there), but it makes no sound otherwise.
I’m still young and hear very well, as exemplified by my annoyance of half-closed bottles of carbonated drinks, which do make a sound.