2022 NHCA Annual Virtual Conference

The attenuation of hearing protection devices (HPD) can change when workers are physically active or when the temporomandibular joint moves. Some earplugs may be more prone to stability issues over a workshift. This study measured changes in personal attenuation ratings of three foam and three premolded earplugs over the course of a 2-hour workshift for thirty factory workers: twenty workers were tested in year 1; nineteen in year 2; and twenty-one in year 3. Not all workers participated in the three years. The personal attenuation ratings (PARs) were measured at the beginning and end of a 2-hour work shift. Workers were initially fit tested to confirm they obtained a PAR of at least 15 dB. Workers were instructed not to touch or adjust their earplugs in any way. To ensure both that workers did not touch their earplugs as well as to ensure workers were protected from noise exposures if their earplugs slipped, workers wore an electronic earmuff. Open-ear and occluded-ear thresholds at 500, 1000, and 2000 Hz for third-octave bands of noise were measured with the NIOSH HPD Well-Fit™ system to estimate PARs.