Pitching a Question...

Hi everyone.
I just found this site and have to say I'm extremely thankful.
I recently had an experience where I had to describe my 'inner ear scream' and couldn't to my satisfaction. However, when I saw the first Hunger Games movie, a scene in that sat perfectly for me as an example to non T sufferers.
It's the scene where Katniss and her friend blow up a huge pile of stuff, and immediately after it all you hear is silence pierced by a single high pitched note.
Perfect.
I've had it for as long as I can remember but it seems to increase when I'm stressing about something.
I've read a few times on this forum people mentioning specific frequencies - How do you find this out? Probably a daft question, but I've been researching a bunch of things today, and thought I'd just ask instead of going down the rabbit hole of the internet - again.
Thanks for the welcome I've already received, and thanks too for any replies to my query.

very grateful,
Lyradette