Hearing protector fit testing is a way to measure the amount of noise reduction, or attenuation, a hearing protector provides while it is being worn by a specific individual. This real-world measurement is referred to as a “Personal Attenuation Rating” or PAR.

OSHA has acknowledged that hearing protection fit testing is a best practice in hearing conservation for over a decade (OSHA/NIOSH/NHCA, 2008).

OSHA has stated that fit testing can be used to help meet the requirements for training and for ensuring proper initial fit and correct use of hearing protectors. (OSHA, 2016).