Acceptance of a semi-custom hearing protector by manufacturing workers.
Davis-RR; Murphy-WJ; Byrne-DC; Shaw-PB
J Occup Environ Hyg 2011 Dec; 8(12):D125-D130
Workers complain about wearing hearing protection for two primary reasons: comfort and communication. Employers are concerned about hearing protection costs. Recent advances in hearing protector technology seemed to address those issues through a semi-custom earplug. This new device was designed to prevent overprotection by incorporating only enough attenuation to bring the worker down into the safe exposure zone. Although initially more expensive than disposable hearing protection devices (HPDs), the semi-custom hearing protector would be expected to last several years. The Hearing Loss Prevention Team of the National Institute for Occupational Safety and Health (NIOSH) was invited by a major auto manufacturing company and the union (UAW) to supervise a longitudinal trial of a semi-custom hearing protector (SonoCustom by Sonomax Technologies, Inc., Montreal, Canada). This protector was advertised as (1) being more comfortable since each plug was custom molded for each worker, and (2) more effective because each plug's noise reduction rating was tuned to that worker's particular job. The company's hearing conservation contractor partnered with NIOSH by recruiting volunteers for the study and providing follow-up usage reports. The study was conducted over the course of 1 year with NIOSH site visits at the start, at 1 month, at 4 months, and at 1-year time intervals. The goal of this trial was to determine worker acceptance of the semi-custom earplug. Compared with the non-custom earplugs used in this study, the SonoCustom ear plugs were relatively new to the market and have not been extensively investigated in the literature. Initial studies have focused on a new way to measure and model the acoustical performance. Wagoner et al. studied speech intelligibility and attenuation while subjects wore the SonoCustom earplugs or two other non-custom, commercially available hearing protectors in laboratory tests and in the field. In the laboratory they were not able to find any statistically significant difference, between the three earplugs, for speech intelligibility or attenuation. Regarding comfort issues, they briefly mentioned that the two non-custom HPDs were judged by the workers to be more comfortable and easier to use than the SonoCustom earplug.
Ear-protection; Ear-protectors; Ears; Hearing; Hearing-protection; Hearing-conservation; Exposure-levels; Exposure-limits; Workers; Work-environment; Sound-attenuation; Sound; Noise-protection; Noise; Noise-levels; Noise-shielding; Noise-shields
Rickie R. Davis, Hearing Loss Prevention Team, Engineering and Physical Hazards Branch, Division of Applied Research and Technology, National Institute for Occupational Safety and Health, 4676 Columbia Parkway, Cincinnati, OH, 45226
Journal of Occupational and Environmental Hygiene