From all I read or heard from doctors in the 40 years that I've had it, is there isn't any treatment for it. I did find that a quiet environment reduced the ringing over time....so the longer that my hunting trip lasted, the more the ringing let up. But, back into a noisy environment, and it picked up again! Eventually, I lost enough hearing in both ears that the ringing wasn't so noticeable.....not that you should find that comforting!!!
Hearing aids have NOT been a solution for me.......at least with regard to tinnitus. And they are a pain in the ____ when hunting(I know, I might be putting them in the wrong place, huh?) Getting them wet makes them fail and invalidates the warranty! I lost one chasing a bull through heavy cover,and that's not the only time one came out when I was hunting! It cost me a $500 deductible to get that one replaced, and not all aids are insured!
People with REAL health problems will not be too sympathetic about our faulty hearing issues, but I've found this one very frustrating for many years.