I had a problem and found the solution, so I’m posting incase anyone Googles and come across this. 😉
Ever since I formatted my computer, I’d hear a constant high-pitched sound coming out of my headphones (very faint) and it’d change in pitch every time I moved my mouse. Turns out muting my line-in in my sound control panel fixed it. Some type of interference I guess.
Hope this helps anyone having the same problem.