The following describes the NIOSH policy for determining the attenuation provided by hearing protection devices for individual workers. This statement updates the 1998 NIOSH Criteria for a Recommended Standard—Occupational Noise Exposure.
Recommendation
NIOSH recommends employers use individual, quantitative fit testing to evaluate the attenuation received by workers from their hearing protection devices. Quantitative fit testing is the physical or psychophysical measurement of noise/sound attenuation provided by a hearing protector. Fit testing results in an objective Personal Attenuation Rating (PAR) that accurately reflects the level of sound reduction an individual worker receives while wearing a specific hearing protector or it indicates an individual has achieved a specified level of protection. Employers should integrate individual fit testing into their hearing loss prevention
programs.