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?
Yes. They drive me nuts. My family had a PC that would buzz whenever you moved the mouse. We have a bunch of cheap LED lamps in my apartment and every one has an especially loud transformer.
My main laptop is making similar noises all the time, I think they come from the CPU.
The CPU itself doesn’t produce sound, but inductors (coils) can. Therefore, when you move the mouse, the CPU power increases, potentially causing inductors to go into resonance.