The Tinnitus Functional Index (TFI) has documented validity both for scaling the severity and negative impact of tinnitus for use in intake assessment and for measuring treatment-related changes in tinnitus (responsiveness). It provides comprehensive coverage of multiple tinnitus severity domains.
The tinnitus functional index: development of a new clinical measure for chronic, intrusive tinnitus. Meikle MB, Henry JA, Griest SE, Stewart BJ, Abrams HB, McArdle R, Myers PJ, Newman CW, Sandridge S, Turk DC, Folmer RL, Frederick EJ, House JW, Jacobson GP, Kinney SE, Martin WH, Nagler SM, Reich GE, Searchfield G, Sweetow R, Vernon JA. Ear Hear. 2012 Mar-Apr;33(2):153-76. The TFI and scoring instructions can be downloaded HERE