Figure 1

Exposure to octave-band noise at 98 dB SPL for 2 hrs causes a transient threshold elevation, which recovers in most frequency regions and causes minimal hair cell loss.

(A) Schematic timeline of the experimental protocol, with animal age indicated. (B,C) Mean DPOAE threshold shifts (±SEMs) for each group, as measured immediately before and after, respectively, the surgery to expose the round window. (D,E) Mean DPOAE and ABR threshold shifts, respectively, as measured 9 days post exposure. Threshold shift is defined relative to the mean thresholds for the same animals measured 2–4 days pre-exposure. (F,G) Mean hair cell loss (±SEMs) for each group. Group sizes were as follows: Normal, n = 7; Trauma + Vehicle, n = 11; Trauma + NT-3[30] , n = 7. In (B,C) the group size for Trauma + NT-3[300] was n = 15. In panels B–G, a subgroup of the high-dose NT-3 group, “Trauma + NT-3[300] e” has been separated out, as defined in Fig. 3B. Symbol keys in each row apply to both panels in the same row.