FIGURE 1.

Noise overstimulation protocol. Following the baseline ABR recordings prior to any noise exposure at the age of 3 months, the noise exposure sessions began. The noise overstimulation protocol consisted of a continuous white noise (110 dB SPL) for 1 h a day for 5 days, with 2 days of recovery before initiating the next stimulation round, until the animals reached 18 months. Additional ABR recordings were performed at 6, 12, and 18 months of age. At these time-points, the recordings in the exposed animals were performed after the 2 days of recovery and right before initiating the corresponding round of 5 days of noise overstimulation.