A Second Study of the Effectiveness of Earplugs as Worn in the Workplace

Abstract

A total of 280 employees from 10 plants took altogether 1400 attenuation tests to determine the protection afforded by insert- type hearing protectors as they are worn in the workplace. User-moulded, expandable acoustic foam, custom-moulded and acoustic wool types of earplugs were evaluated. Results showed average protection ranged from 9 dB at 125 Hz to 29 dB at 3150 Hz. It is concluded that the workplace noise protection received from earplugs is dependent upon earplug design, and that for a given protector these may well be large differences between attenuation values established in the laboratory and those received in the industrial setting.