Evaluating Earplug Performance over a 2-Hour Work Period with a Fit-Test System.

Area of Science:

• Occupational Health
• Audiology
• Noise Exposure Assessment

Background:

• Workers require hearing protection devices (HPDs) to prevent occupational noise-induced hearing loss.
• The effectiveness of HPDs can change over time due to factors like fit and wear.
• Understanding attenuation changes is crucial for ensuring adequate noise reduction.

Purpose of the Study:

• To evaluate changes in sound attenuation over time for properly fitted HPDs.
• To assess the real-world effectiveness of foam and premolded earplugs in a noisy industrial environment.
• To determine if initial attenuation levels are maintained during a typical work period.

Main Methods:

• Fit testing and Personal Attenuation Rating (PAR) measurements were conducted on 30 brewery workers.
• Six types of earplugs (3 foam, 3 premolded) were tested.
• PARs were measured before and after a 2-hour exposure to hazardous noise levels.

Main Results:

• Average decreases in PAR ranged from -0.7 to -2.6 dB across all tested earplug types.
• Significant changes in PAR were noted for specific foam and premolded earplug types.
• Ninety-five percent of final PAR measurements met the minimum acceptable attenuation of 15 dB.

Conclusions:

• Properly fitted earplugs demonstrate effectiveness in reducing worker noise exposure over an extended period.
• A slight decrease in attenuation during a work shift is possible and should be considered.
• Training and assessment of HPD adequacy must account for potential attenuation changes over time.