NIOSH’s Hearing Loss Prevention Effectiveness Study

Noise-induced hearing loss continues to be one of the most common occupational disorders, even in workplaces where workers are protected by hearing loss prevention programs (HLPPs). Although standards and regulations vary by country, virtually all hearing loss prevention programs require several elements: the measurement of noise exposures; the implementation of noise controls to reduce noise levels; conducting hearing tests on exposed workers; training of exposed workers; the use of hearing protection by exposed workers; and certain recordkeeping activities.

NIOSH’s Occupational Noise Exposure Criteria Document and the Practical Guide for Preventing Occupational Hearing Loss have details about implementing a successful hearing loss prevention program.  However, despite the widespread adoption of HLPPs, there are no agreed-upon standards about how to evaluate the effectiveness of such programs.  Also, there are few evidence-based tools allowing workplaces to evaluate their own programs.

A team of researchers from the University of Washington, University of Michigan, and Yale University recently carried out a NIOSH-funded study of HLPP effectiveness. The team studied HLPPs at 14 U.S. facilities operated by a single multinational metals manufacturing company.  Collectively, these facilities employed more than 15,000 workers.

The team identified exposures to high noise among many workers in the HLPPs; between one-third to two-thirds of full-shift dosimetry measurements at each facility were over 85 dBA. They also calculated an average annual HLPP costs of about $294/worker.  Most of the facilities had a strong management commitment to preventing hearing loss, and workers at most facilities showed a strong personal commitment to protecting their hearing on the job.  However, workers and management at few sites showed a commitment to protecting hearing off the job.

Based on the results of this research, the team created two self-evaluation tools for use by HLPP managers. The first tool is a checklist  designed to evaluate facility compliance with mandatory HLPP requirements, as well as their adoption of best practice methods for preventing hearing loss.  The second tool is a calculator that allows facilities to estimate the cost of their HLPP, both overall and by program element.  Both tools are available on the NIOSH hearing loss prevention website.

Collectively, these evidence-based tools should provide HLPP managers the ability to evaluate and improve their programs in order to better protect workers from noise-induced hearing loss.