I also have this thing, but maybe not all the time, though it does crop up regularly.
Had a think on the process and maybe concluded that it was down to concentration, as in when I was concentrating tv,web etc the high pitched whine would start.
I developed a remedy, and it works for me but in a room of people you’ll look like a complete maniac.
As i think its the concentration issue, i throw my head back and forth, turning about.
The point is to focus, and refocus on objects around the room, near and far. Look at the floor,swivel around to look at the ceiling, to the floor, the windowsill etc, conducted quickly, so not resting on an object for more than a split second, then to the next object until the noise dissipates. Which it does.
I suspect the brain is trying to follow and that distraction means it isnt ‘concentrating’ on the sound.
Try it. But you are making lots of rapid jerky head movements, you’re not doing it slowly. In fact it would probably like a manic version of Stevie Wonder on x3 speed 😆
I hope the effect works for you to. But again I think its a brain/concentration thing 😕