I have had a ringing in my ear for 5 years. I tried everything. Finally I tried SOD3, manganese, NAC, glutamine, SAMe. Tinnitus gone in a week.
http://www.godlikeproductions.com/forum1/message1130666/pg1
I don't know what some of those are. And a disclaimer, I have no idea who this is or a lot about that forum although it looks to be a conspiracy theory discussion.