Mining Project: Evaluation and Development of Hearing Loss Interventions

Research Summary

Noise-induced hearing loss (NIHL) is the most common occupational illness in the United States today, with 22 million workers exposed to hazardous noise. To prevent NIHL, NIOSH's Hearing Loss Prevention and Noise Control program has developed multiple noise controls and intervention tools, but there is a need for evaluation and outcome data on the interventions and the hearing loss program. It is also important to continue developing new tools that workers can use to effectively reduce their exposure. Therefore, the purpose of this project was to develop and evaluate new products, determine the effectiveness of existing interventions, and promote the use of those interventions.

This project consisted of two major tasks:

Task 1. The effectiveness of existing NIOSH-developed mining machine noise controls was assessed. These controls include urethane-coated chains for continuous mining machines, bit isolators, chuck isolators, and collapsible drill steel enclosures for roof bolting machines. Additional noise controls were evaluated as the project progressed. Noise control adoption was promoted through workshop and training campaigns that focused on effectiveness, ease of use, and improved working environments resulting from implementation.

Task 2. This task involved a collection of interventions that workers use to effectively reduce their noise exposure. These included exposure feedback systems, training systems for improved audibility through hearing protection devices (HPDs), and handouts/documents focusing on various topics related to reducing NIHL.

Additionally, an audiometric surveillance component was used to track the hearing status of the mining industry over time.

As a result of this project, as more noise controls are implemented and greater focus is placed on the importance of reducing NIHL, we expect to observe a gradual decline in hearing loss as measured through surveillance.