Fig. 4

The noise immediate group demonstrated increased mRNA expression levels of tumor necrosis factor alpha (TNF-α), interleukin 6 (IL6), interleukin 1 beta (IL1β), and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), compared to control group (*P < 0.05, Mann–Whitney U test). The noise 4-week group showed lower mRNA expression level of NF-κB than control group (**P < 0.05, Mann–Whitney U test). (error bar =  ± standard errors)