Huh. Fixed just like that with one click!
Some laptop/notebook computers will be silent while running on their AC power adapters, but then when they start using battery power they make noise. Annoying, high pitched, whine/squeal/chirpy type noises. Typically, when you are barely using the computer the noise is worse. Typically the noise will stutter when you scroll with the mouse (which takes just a liiiitle more processing power).
This is an audio frequency resonance in the electronics, caused (I think) by the power converter in your notebook computer. It is switching (power converting) slowly enough for you to hear, because the computer is barely using any power. And it is rather a nasty little noise, if it’s the loudest thing you hear as the next-loudest thing in your room is your own breathing. My Dell e1705
does did this pretty reliably when just reading plain web pages, for example. Apparently this is something that ALL notebook computer manufacturers trip over from time to time.
On a whim, I decided to look up this problem online and see if anyone had a fix. On some Lenovos, apparently, you only need to install Laptop Whine Killer. My computer showed no change with that. Some people advise turning off a certain power-conserving state ( C3 ) with RMClock, which will cost you (mumble) minutes of battery life. One person recommended turning off their Bluetooth module’s power conservation mode to eliminate the noise. I checked: my BT was set to let Windows turn it off to conserve power. I un-checked that box and the computer got WAY quieter. Make a SMALL change to your power plan like any of these, and see if it helps.
Cheers for silent computers!
Okay, maybe not totally silent. But when you start from “nails on a blackboard”, going to “someone playing piano quietly in the room down the hall behind closed doors” is a huge improvement. There is still some noise, but not nearly as bad. People with worse hearing than mine wouldn’t be able to hear what’s left. Close enough.