Changes in the mean hearing threshold levels in military aircraft maintenance conscripts

Area of Science:

• Occupational health
• Audiology
• Aerospace medicine

Background:

• Aircraft maintenance personnel face significant noise exposure.
• Understanding noise effects on hearing is crucial for occupational safety.
• Hearing threshold levels (HTLs) are key indicators of auditory health.

Purpose of the Study:

• To investigate the impact of aircraft noise on the hearing threshold levels (HTLs) of aircraft maintenance conscripts.
• To assess auditory health changes during a 2-year mandatory military service period.
• To identify potential risk factors and protective measures for hearing loss in this demographic.

Main Methods:

• Study included 3,000 male aircraft maintenance conscripts working in a military runway area.
• Hearing threshold levels (HTLs) were measured and analyzed at frequencies of 2-4 kHz.
• Noise exposure duration and its correlation with HTLs were examined across different ranks.

Main Results:

• Despite increased noise exposure with higher ranks, HTLs showed a decreasing trend, possibly due to learning and adaptation effects.
• Sudden deafness was observed in 6 conscripts (0.2%), suspected to be noise-induced.
• No significant adverse effect on overall HTLs was found during the 2-year service period.

Conclusions:

• While overall HTLs did not worsen, the incidence of sudden deafness highlights the risks of loud runway noise.
• Enhancing hearing conservation programs for short-term military personnel is recommended.
• Pre-enlistment baseline audiogram tests and focused prevention of sudden deafness are crucial.