Tinnitus and impulse noise-induced hearing loss in drop-forge operators

Area of Science:

• Occupational Medicine
• Audiology
• Environmental Health

Background:

• Tinnitus is often associated with noise-induced hearing loss, particularly from impulsive noise.
• Understanding the prevalence and characteristics of tinnitus in industrial settings is crucial for hearing conservation.

Purpose of the Study:

• To estimate the prevalence of tinnitus in industrial workers exposed to impulse noise.
• To analyze the relationship between impulse noise exposure, hearing loss, and tinnitus characteristics.

Main Methods:

• Otological and audiometric examinations were conducted on 261 drop-forge operators exposed to impulse noise (peak levels of 135 dB).
• A control group of 169 age-matched individuals with no occupational noise exposure was included for comparison.
• Tinnitus complaints were analyzed in both groups, correlating findings with exposure duration and audiometric results.

Main Results:

• A significantly higher prevalence of tinnitus was found in the exposed group (70.4%) compared to controls (3.5%).
• Tinnitus prevalence increased with longer exposure duration, exceeding 10 years.
• The approximate pitch of tinnitus correlated with the frequencies most affected by impulse noise-induced hearing loss, typically at 6 kHz.

Conclusions:

• Impulse noise exposure is a significant risk factor for developing tinnitus in industrial workers.
• Noise-induced tinnitus can be more debilitating than hearing loss itself, emphasizing the need for robust hearing conservation programs.
• Strict adherence to hearing protection measures is essential to mitigate the risk of tinnitus and hearing damage in noisy industrial environments.