Tinnitus Functional Index (TFI) score greater than 50. Tinnitus unresponsive acoustical and behavioral therapies. Prospective subjects must have received at least one acoustical (masker, hearing aid, Neuromonics®) or behavioral therapy (cognitive behavioral, directive counseling, tinnitus retraining therapy) to be eligible for study enrollment, but partial response to conventional therapy does not exclude a prospective subject if the individual meets the TFI > 50 study participation threshold.