Gap detection ratio values (GAP; gap detection/startle-only response) and prepulse inhibition (PPI) ratio values (PPI/startle-only response) measured at 1 day (A and B), 14 days (C and D), 28 days (E and F), and 90 days (G and H) after blast exposure. Note that the rats showed significant deficits in gap-detection and PPI inhibition at 1 day post-blast, followed by marked recovery at 14 days post-blast. Further recovery was demonstrated by the lack of deficits in GAP (E and G), and fewer deficits on PPI at post-blast days 28 and 90 (F and H). These indicate signs of transient tinnitus, as well as a complex time course change. Error bars represent standard error of the mean (*p<0.05; BBN, broadband noise; PB1D, 1 day post-blast; PB14D, 14 days post-blast; PB28D, 28 days post-blast; PB90D, 90 days post-blast; Pre, pre-blast).