FIGURE 7.

Line graphs illustrating the interpeak positive (colored lines) and negative (black lines) latency times (ms) plotted as a function of frequency in non-exposed and exposed rats. In the 3-month-old group, previous any noise exposure, there were no differences between E and NE groups in any of the interpeak positive latencies evaluated (A–C). However, there was a significant effect of sound stimulation and age on the interpeak positive latency times at 6 (D–F), 12 (G–I), and 18 (J–L) months. Accordingly, in the I-II interpeak positive latency times whereas no differences were observed between NE and E rats, longer negative latencies in the exposed animals were detected at the highest frequencies in 18-month-old (D–J) animals. In the II-IV (E,H,K) and I-IV (F,I,L) interpeak latencies, longer times were detected in the exposed animals at the highest frequencies at 6, 12, and 18 months when compared to non-exposed rats. PIL, Positive Interpeak Latencies; NAL, Negative Interpeak Latencies, ^∗p < 0.05, ^∗∗p < 0.01.