Longtime sufferer of tinnitus. This has been my understanding as well. From what I understand, once the hair dies, the brain seems to compensate by filling it with eternal noise. If there is a cure (my hopes are low), my guess is that we need to have a better understanding of the brain.

A random idea: that mechanism reminds me of phantom limb pain. I wonder if there could be a treatment analogous to mirror therapy, at least for monaural tinnitus.

Searching just now turns up http://scopeblog.stanford.edu/2010/01/11/tinnitus_the_ea/ and http://www.therasmusforum.com/tinnitus-type-is-similar-to-ph...

I've tinnitus, and hearing lost since 20 years old, I was musicians, playing keyboards. Now I am 42 y old. I hope, maybe soon we could have a solution, take a look this article -> https://www.newscientist.com/article/mg22229662-400-deaf-peo...

Can be from physical damage to the stereocilia in the inner ear.