In my experience, early intervention can help. I got tinnitus at the age of 30 (from a pressure trauma during scuba diving). I received some kind of dementia medication after 2 weeks, and the tinnitus was gone not long after that (and never reappeared). The doctor funnily said that a side effect is that I'm gonna feel smarter :) I'm not sure if it was the medication, or the tinnitus was just temporary anyway, but it was a really loud and unbearable noise for a couple of weeks.