We used the hearing-protective device-adjusted value of the 8-hour time-weighted average equivalent sound level to classify participants into 3 exposure groups by selecting the median and third quartile as cutoff points in the distribution of noise exposure among all subjects。The 578 workers were subdivided into a high-exposure group (n=152; noise level: ≥85 dBA), an intermediate-exposure group (n=221; noise level: 80–