Figure 3
Impaired ABR thresholds after blast exposures. (A) Representative auditory brainstem responses during the first 10 ms after presentation of 80 dB SPL tone-burst at 4, 32 and 40 kHz. (B) ABR thresholds of right and left ears to tone burst stimuli from 4 to 40 kHz. ABR thresholds significantly increased at D1 across all test frequencies. Gradual recovery of ABR thresholds was noted in the low to mid frequencies (4–22 kHz) at D7, D14 and D28, although thresholds were still elevated relative to baseline (BL, solid line). (C) Right ear ABR threshold alterations following injury. Compared to acute injury at D1, ABR thresholds from 4 to 32 kHz stimuli partially recovered at D14 and D28, but were still significantly elevated compared to BL. Significant recovery was not observed at 40 kHz at all-time points tested after blast exposure. Percentage changes in right ear ABR wave I amplitude (D) and latency (E) following injury measured at 80 dB SPL. ABR wave I amplitude decreased and latency increased significantly at D1 compared to other time points. One-way ANOVA followed by Tukey’s multiple comparisons test, #p < 0.01 for a group that was significantly different compared to another group; *p < 0.05, **p < 0.01, ***p < 0.0001, n = 8 each group.
