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 hear coil whine from my PC’s graphics card, but that’s it.
Edit: Also our home stereo system (not the speakers) when it’s turned on.
I used the have a PC that ran Windows XP, and when I moved the mouse, sound was heard from the speakers. It probably had a cheap sound controller on the motherboard.