Is there a relationship between occupational noise and hearing levels, sleep quality, and QoL of the factory workers?

We assessed the hearing level, sleep quality, depression status, and life quality of the employees.

The research group contains 380 (56.7%) of 669 employees working in the factory. We used a questionnaire, noise measurement (2016), pure tone audiometry test results of (2015, 2016). SF-12 (short form), mini sleep questionnaire (MSQ), and Beck depression scale.

The employees’ mean working period is 13.5 ± 11.9 years. The mean ambient noise level of the factory is 75.5 ± 7.3 dB. We detected hearing loss at 18.6% and 23.2% in 2015 and 2016, respectively. The frequency of hearing loss is 4.7% at the employees working below 85 dB and 27.8% percent at the employees working above 85 dB. Mean working period of the employees with hearing loss (19.7 ± 11.7 years) is higher than mean working period of the employees without hearing loss(13.2 ± 11.8 years) (p < .0.05). The 27.8% of the employees working above 85 dB are used to earmuffs, 44.4% of them sometimes use earmuffs; 38.9% of them are used to earplug; and 44.4% of them sometimes use earplug. Back depression scales showed 31.1% minimal, moderate, or severe depression. The sleep quality of employees working above 85 dB is worse than the others (p < 0.05). SF-12 QoL scores were 39.41 ± 5.59 (physical health) and 36.10 ± 7.76 (mental health). There was not a statistically significant association between scale scores and ambient noise level and hearing level of the workers (p > 0.05).

We suggest the use of personal protective equipment. Working in the noise above 85 dB affected workers’ sleep quality to be poorer.