Fit Testing of Hearing Protection-September 2021

Millions of employees are exposed to noise in the workplace and every year thousands suffer from hearing loss because of it. As the result of limited regulation on employee noise exposure and cost, most employers rely on hearing protection devices (HPD) to protect their employees. The National Institute of Occupational Safety & Health (NIOSH) rates muffs, plugs, and other devices and assigns them a noise reduction rating (NRR). Unfortunately, the NRR ratings are determined by laboratory testing and do not accurately reflect their noise attenuation when used in the field. NIOSH also has published information on how to properly wear HPD and has a “hearing protection quick test” where the employee listens to two separate tracks while sitting in a quiet room. It allows the employee to adjust his HPD so he/she gets the best possible fit.

Hearing protection manufacturers have attempted to devise a better method of demonstrating the effectiveness of their products. The result is fit testing for hearing protection. Although not a requirement, OSHA has recognized fit testing of HPD as a useful best practice. ANSI/ASA S12.71-2018, American National Standard Performance Criteria for Systems that Estimate the Attenuation of Passive Hearing Protectors for Individual Users, is the first standard that sets the criteria for fit-test systems to ensure accurate measurements and transparent reporting of fit-test results. 3M has a E-A-Rfit Dual-Ear Validation system which is one of the available fit-testing hardware and software systems. The effectiveness of the HPD is typically measured as a personal attenuation rating (PAR) which is subtracted from the known noise exposure to estimate the total noise exposure a single person when wearing the tested HPD.

Similar to quantitative fit testing for respirators, the employee wears a HPD connected to the detection equipment in a separate room or mobile testing facility. Although fit testing may be useful as a training device to show how well the individuals wear their hearing protection, it does not indicate if the employee will properly wear his/her hearing protection while working. As with most personal protection devices, hearing protection is no substitute for eliminating or reducing noise in the workplace and the best strategy is to implement engineering or administrative controls. An effective hearing conservation program, noise controls, and hearing protection devices are all needed to protect employees from the effects of noise.

For more information on this topic and to discuss your company’s safety and industrial hygiene needs call OccuSafe at (214) 662-6005 or visit us at

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