Level of noise-induced hearing loss and associated factors among workers in Bishoftu central air base of Ethiopia

Abstract Background Excessive occupational exposure to noise results in occupational hearing loss was considered a major public health problem. Since the expansion of the aviation industry and its exposure to the intensity of noise level was simultaneously high. Objective This study aims to assess the level of noise-induced hearing loss and associated factors among workers in the Bishoftu central air base in Ethiopia. Methods Institutional-based cross-sectional study was conducted among 260 central air base workers through face-to-face interviews; an environment noise survey with an audiometric test had been conducted to collect data. Data were entered by Epidata version 3.1 and SPSS was used to analyze the data. Finally, a statistical analysis such as descriptive statistics and binary logistic regression analysis was applied. A P-value < 0.05 at 95%CI was considered statistically significant. Result The overall prevalence of noise-induced hearing loss and hearing impairments were 24.6 and 30.9%, respectively. From this, 16.9% bilateral and 7.7% unilateral noise-induced hearing loss. The highest prevalence noise level was recorded for workers who were exposed to noise levels greater than 90 dBA. Around 21.9% were males with an age category between 18 to 27 years were exposed to noise-induced hearing loss. Similarly, the lowest experience was between 1 to 10 years of exposure to noise-induced hearing loss by 16.9% with working department transport helicopter (4.7%), transport airplane (4.7%), and daily maintenance (3.5%). Those participants who were exposed to noise-induced levels at work place previously were five times (AOR = 5.0, 95% CI: 1.74–14.36) more likely exposed to the sound noise level at the workplace than those workers not exposed at work place previously. Those workers who were exposed to greater or equal to 90dBA noise level were 4.98 times (AOR = 4.98, 95% CI: 2.59–9.58) more likely exposed to noise-induced levels than those who were exposed to less than 90dBA noise level. Moreover, male air base workers were 3.5 times more likely exposed to hearing impairment than female workers (AOR = 3.5, 95%CI 1.01–12.0) and participants who have abnormal otologic examinations were 1.9 times more likely exposed to hearing impairment than those who have normal otologic examinations (AOR = 1.9, 95%CI 1.02–3.54). Conclusion Workers were exposed to high levels of occupational noise that could induce immediate hearing loss. The prevalence of hearing loss was significantly high.