Strategies of the Tinnitus Research Consortium.
CONCLUSIONS: Research supported by private philanthropy complements governmental support of research, and its organization can undertake analysis of the whole field, identify the initial steps required to advance the field, draw attention to the intellectual challenge of a field such as tinnitus, recruit scientists to a neglected area, direct support to the most promising research approaches and opportunities, and dedicate support to those endeavors. OBJECTIVES: The efforts of the Tinnitus Research Consortium (TRC) are to accelerate progress in basic and clinical research on tinnitus. METHODS: The TRC analyzes the field of tinnitus research, brainstorms for new research approaches to tinnitus and provides guidance to the scientific community through requests for applications (RFAs) on promising research approaches and opportunities. The analysis of the research field has focused on the validity of animal models of tinnitus, the need for a standardized outcome measure in clinical trials, and the control of confounding variables in basic and clinical studies of the mechanisms of and site(s) associated with tinnitus. RESULTS: The TRC judged that the existing animal models were worthy of further study and refinement and that additional animal models should be developed. In response to an RFA, a project for the development and validation of the new Tinnitus Functional Index was initiated. A confounding aspect of experimental induction of tinnitus is the occurrence of hearing loss. The experimental manipulation causing the hearing loss may or may not cause tinnitus. Segregation of the correlates of tinnitus from the consequences of hearing loss requires the inclusion of a second control group: animals that have been subjected to the manipulation for the induction of tinnitus and have a hearing loss but fail to exhibit signs of tinnitus. Comparison of normal animals, animals with hearing loss without tinnitus and animals with hearing loss and tinnitus greatly enhances the value of the research. Clinical research on the mechanisms and sites of tinnitus is also confounded by this problem, and the solution is to include controls matched for hearing loss without tinnitus.