In human, several association studies have demonstrated that CDH23 gene,15, 16 human 8-oxoG DNA glycosylase 1 (hOGG1) gene,17 catalase (CAT) gene,18 heat shock protein 70 (HSP70) gene,19 potassium voltage-gated channel, Isk-related family, member 1 (KCNE1) gene and potassium voltage-gated channel, KQT-like subfamily, member 4 (KCNQ4) gene20 might be involved in the susceptibility to NIHL. This evidence concerns the gene CAT and noise induced hearing loss.