There are various places in the U.S. that offer transcranial magnetic stimulation, which has been used for some time to treat depression. There have been several clinical trials looking at if this therapy is effective on tinnitus.
http://www.sciencedaily.com/releases/2012/09/120918184754.htm
University of Texax-Dallas also has been doing a well-publicized trial on vagus nerve stimulation (does not involve magnetic technology, but a somewhat similar idea).
http://www.utdallas.edu/ctech/projects-overview/vagus-nerve-stimulation-for-tinnitus/
But as far as I know, there has not been any definitive research so far that shows either of these treatments indeed works on T. I actually had much hope for the UT-Dallas technology and applied for their trial but was rejected. We will see how it all plays out.