Aww, it was just a tangential connection to this situation. Sorry if I disappointed you.

Unfortunately recovering the dead cells in the inner ear is impossible at the moment. One option is Transcranial Direct Current Stimulation (tDCS) as a form of non-invasive treatment. 40% of patients reported improvement although is experimental at the moment. Other approaches use deep brain implants.

The moment we find a cure for Parkinson that's when we probably also find a cure for tinnitus. Let's be hopeful and wait.

Folmer, R.L., Theodoroff, S.M., Martin, W.H., Shi, Y. (2014) “Experimental, Controversial and Futuristic Treatments for Chronic Tinnitus.” Journal of the American Academy of Audiology, 25:106-125.