Fig. 2.

Threshold elevation and hearing thresholds of noise exposed animals. Graphs of mean hearing threshold shifts (A) and hearing thresholds (B) of animals exposed to noise. (A) Hearing threshold for the 24 kHz and 30 kHz tone pips significantly increased during the second and third ABRs, (*, p < 0.05 and **, p < 0.01 respectively) following noise exposure. An increase in hearing threshold for 16 kHz was detected during the third ABR, after two noise exposures (p = 0.09), while the hearing threshold for 12 kHz remained unaffected. Please note that ABR number refers to each trial as described in Fig. 9.