... no clue and none of the doctors that i've seen have helped me out in the least. I've narrowed it down to either major stress i was going through at the time, a sinus infection that i had, some type of incorrect shoulder/back workout, or some ibuprofen(which is known to be ototoxic) i took for the pain i was experiencing from said workout session
I never blast my music and don't go to shows anymore so it definitely isn't sound related. But my hearing/ears are more sensitive now and i get temporary spikes(few seconds to minutes) from loud noises.