I had a quad bike accident years ago. Fractured my skull, nose and a load of bones in my ear.
I have a drop off in high frequencies in that ear ever since. I get by having to flip the phase of my tracks quite often to make sure things are balanced.
Hopefully things will improve for you.
Not sure of your problem but one thing Ive been looking at (for swimming mainly) are bone conducting headphones. They sit of your check bones and your brain picks up the vibrations and converts then to sound. Not sure how good they are or where your issue is but that might be a solution???
1 Like