The relative gene expression changes of HSP-27, HSP-70, HSP-90, CDKN-1A and CTSD in the AC induced by noise exposure. (A) The expression of HSP-27, HSP-70 and CTSD showed significant changes in the AC collected from noise exposed group compared to the control group (*, p<0.05). The expression change of HSP-90 and CDKN-1A were not significant. (B) Comparison of the gene expression in the left AC (ipsilateral to the exposed ear) to the right AC (contralateral to the exposed ear) in the noise exposed rats. The expression of CTSD, HSP-27, HSP-70 and HSP-90 was slightly higher in the right AC compared to the left AC, but not significant.