Prevent hearing loss in mining
In many ways, mining operations present one of the most difficult challenges for hearing conservation: loud, heavy machinery in confined reverberant space, coupled with a need for critical communication among co-workers. These are potent ingredients for noise-induced hearing loss (NIHL).
Nearly three out of four South African miners are overexposed to hazardous noise levels, and one study of coal miners over the age of 50 found that up to 90 percent have debilitating hearing loss.
“Several companies have successfully reduced the rates of hearing loss among their noise-exposed workers,” says Brad Witt, director of Hearing Conservation, Honeywell Safety Products. How?
The prevailing assumption is that “anything in my ear will protect my hearing _ it doesn’t really matter what it is”. In reality, ear canals come in different sizes and shapes, affecting both fit and protection levels, as well as comfort. A mine site that offers only one size or style of earplug sabotages its own hearing conservation efforts, as few workers will be adequately protected.
Like a cork in a bottle, an earplug that is too large, or too small, will never achieve an acoustic seal. A variety of hearing protection sizes and styles can be accomplished with little or no increase in cost.
A recommended mix of sizes or styles to optimise the fit of earplugs at a mine site would be: large foam earplug; smaller foam earplug; large reusable earplug; and smaller reusable earplug.
It is a myth to assume critical communication and hearing protection cannot co-exist. Studies show that communication levels improve for most workers wearing protectors in loud noise. Hearing protectors are now available that reduce the overprotection and communication interference found in conventional protectors.
Several earplugs and earmuffs have been designed to maximise communication through uniform attenuation; allowing wearers to hear important sounds (such as co-workers, warning signals, radio and communication systems, and maintenance sounds from machinery) more naturally, while still protecting the wearer from harmful noise levels.
If a miner feels the earplugs are isolating him from co-workers and warning signals, he will avoid using them, or simply insert them halfway, providing minimal protection.
The motivation to protect hearing must focus on how using hearing protection today affects long-term health and well-being tomorrow. Quality of life deteriorates over time as workplace-induced hearing loss becomes more noticeable.
One-on-one training far exceeds group training in the fit and effectiveness of the hearing protector, even if this is just a one-minute explanation of how to fit earplugs at the time of new-hire orientation. Many hearing-protector manufacturers can provide training tools to assist in this effort.
In addition to ensuring each worker is adequately protected, fit-testing provides employers with good documentation of protection. If a spurious claim for hearing loss is filed, the employer who has administered fit-testing can show that a worker was properly fitted with adequate protection, and properly trained in its use.