FIG. 7.

DPOAE level shifts (LS) averaged across 2–16 kHz as a function of time. In the control groups, after noise exposure, a maximal LS was observed at 8 h and remained relatively constant until 24 h, while permanent LSs were observed at 7 days. A partial recovery of LS occurred during the 24-h–7-day period. Animals in the treated groups showed a similar time course of functional recovery but a significant reduction in LS from 8 h to 21 days when compared to control animals. The number of ears tested was: 18 (8 h), 18 (24 h), 18 (7 d), 16 (21 d). Data were analyzed using a two-way ANOVA with the Bonferroni test, *p < 0.05; ***p < 0.001 or 0.0001 and plotted as mean ± SEM.