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 remember when I was little I used to hate my grandma’s old tv because there was always a high pitched noise that came from it when it was turned on or off, my grandma was never able to hear it though and I couldn’t understand why till I learned about how we struggle to hear higher frequencies as we age.