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?
My father used to make fun of me for saying that I could hear the TV on even if it was muted, or that I could hear the furnace ‘scream’ before it came on.
One year, I got as a gift for Christmas, a handheld recorder and a fancy microphone from my stepfather a university music professor And that recorder could actually record the sound which he was able to show me on the computer.
That was like 25 years ago, I’ve been working with computers ever since, and now I am familiar with many many many devices that make high pitch whines.