Abstract
Background: In order to verify an aircraft's airworthiness, aircraft maintenance technicians
(AMTs) play a crucial role in the aviation industry. These AMTs are exposed to the loud
workplace noise produced by airport operations or maintenance equipment. Numerous people
in many different industries, including the military, building, farming, mining, aviation,
manufacturing, foundries, and other related fields, are impacted by noise. As a result, it is
necessary to calculate the 8-hour Time Weighted Average (TWA) of an individual's exposure
and compare it to the 85 dBA NRL.
Objective: The study aimed to investigate the occupational noise exposure levels among
aircraft maintenance technicians in Gauteng.
Methods: In this quantitative descriptive cross-sectional study, data was collected from two
hundred-eight (n=208) AMTs using questionnaires. QUEST Technologies Noise Dosimeter
was also used to collect personal noise measurements from 30 participants during aircraft
maintenance. The 8h TWA-exposure was calculated to compare with the regulated NRL of 85
dBA. SPSS was used to construct descriptive statistics such as frequency distributions and
confidence intervals, and logistic regression was used to investigate associations between
perceived noise levels and some socio-demographic factors.
Results: This study revealed that study participants, 82.2% (n=171) were exposed to high noise
levels, while 17.8% (n=37) were not. The risk factors for developing NIHL included age group
51-60 years (AOR: 8.07, 95% CI 1.39 - 46.94), being male (AOR: 1.39, 95% CI 0.56 - 3.47),
previous employment for more than ten years (AOR: 7.63, 95% CI 1.26 - 46.43), senior and
licensed technicians (OR = 2.95, 95% CI 1.25 - 6.94, and OR = 15.17, 95% CI 3.32 - 69.34),
noise exposure among technicians (OR = 7.53, 95% CI (3.35 - 16.92), spent 5–9 years in
previous job (OR = 9.63, 95% CI 3.47 – 26.71), bothered by noise (AOR: 3.28, 95% CI 1.19 –
8.99). The noise levels at the aircraft maintenance organisation (AMO) are at or above the
South African regulated NRL and those exposed to occupational noise are more likely to
develop noise-induced hearing loss (NIHL). Line maintenance had the highest 8h TWA daily
noise exposure level of 90.93 ± 5.59 dBA, followed by minor maintenance with 85.94 ± 4.65
dBA and base maintenance with 81.86 ± 8.33 dBA.
Conclusion: Noise levels at the AMO are at or above the legislated NRL of 85 dBA. As a
result, if employees work 8 hours or more without adhering to the current control measures and
the HCP in place, AMTs may experience noise induced hearing loss over time.