I too suffer from an intermittent tinnitus in my left ear. It is a kind of a sound you would hear between FM stations. Not particularly high in frequency but in the upper midrange. I too, went to the ENT and after getting all kind of tests, it was determined I just have a mild high frequency loss above 8KHz in that ear. Below 8K is fine. My right ear is fine.
When listening to music, I would hear an increase in noise in my left ear and it did bother me for a while. The tinnitus now comes and goes and doesn't bother my listening to any significant degree. Some days it's gone, other days it's there. I was told salt intake, stress and anxiety would increase it. ENT says with time, you become accustom to the noise like anything else and it will, at some point, not be an issue. Mine bothered me for the first 6 months or so and now I don't notice it unless I specifically think about it.
Make sure though you protect those ears from now on out. Don't listen for any appreciable time over 85db.
