Blast-induced tinnitus: Description of a Novel Rodent Model

The incidence of tinnitus has greatly increased over the last decade due to the increase in blast-exposure in our military warriors. To examine if/how the damage associated with blast-induced tinnitus differs from tinnitus induced from sound-exposure, we created a novel model for the creation of tinnitus following a 20 psi blast pressure wave. Animals were tested for hearing and tinnitus using acoustic startle responses (i.e., startle, pre-pulse, and gap detection tests). Tests were performed on at least 3 non-consecutive days. The results were averaged to determine a baseline response for the animals. Animals were then placed into a custom blast chamber and exposed to a 20 psi blast pressure wave. The animals were then tested at least twice per week post-blast-exposure for tinnitus. Sixty-six percent of the animals tested had developed tinnitus after blast exposure. As this percentage is similar to reported incidence of tinnitus in the military population after blast-exposure, we believe this to be a viable model for examining the damage and potential prophylactic treatments for blast-induced tinnitus in an animal model.