According to OSHA regulations, hearing protection devices “shall be provided” when harmful workplace noise cannot be controlled by other means. Sounds simple, right? But guess again. With a plethora of product options available and new technologies offering improved capabilities, airport and airline safety managers are often at a loss to understand which hearing protection device (HPD) is best suited for their applications. Here then, is a brief “field guide” to HPDs which should help ease the selection process.
Typically worn once and thrown away, single-use, or disposable, earplugs offer workers a high degree of comfort, performance and convenience. Single-use earplugs are offered in a wide range of styles and materials, ranging from the 35-year-old yellow PVC barrel earplug to the latest contoured polyurethane (PU) foam earplugs.
Single-use earplugs range from high-density earplugs with a maximum NRR of 33 dB, to lower-pressure foam style earplugs.
Advances in single-use earplug design have incorporated new materials and designs that facilitate communication without compromising overall protection.
They are also offered with and without cords. Corded earplugs are convenient for workers who are intermittently exposed to noise as they can be worn around the neck when not in use.
Bulk dispensers offer employers a cost-effective solution, providing savings upwards of 10 percent per year in HPD purchases alone.
While significantly more expensive than single-use styles, multiple-use earplugs can be more economical over time.
Multiple-use earplugs are typically molded out of a variety of vinyl, plastic and silicone materials, featuring a rigid stem for insertion and pliable flanges to create a comfortable seal in the ear canal. Unlike most single-use earplugs, multiple-use styles do not require rolling, and are much easier to insert and remove. Some multiple-use earplugs are designed to fit all ears, while others come in sizes to accommodate different canal shapes and sizes and are made of patented Thermoplastic Elastomer (TPE).
With proper maintenance, multiple-use earplugs can be worn for approximately two to five weeks. One handy new feature is a detachable cord that allows them to be worn corded or uncorded according to preference.
Another multiple-use option are banded earplugs. These are basically a pair of earplugs held together by a plastic band and are very useful for people who move in and out of noisy areas. Banded earplugs are a kind of hybrid between earmuffs and earplugs. They provide the portability and convenience of earplugs, with the ease of use of earmuffs. They are also an alternative in hot temperatures where earmuffs can become uncomfortable.
As a best practice, safety managers should enlist a small group of workers whose opinions they trust, and have them wear different styles over a period of time to narrow the selection. Hearing protection salespeople will usually provide samples for this purpose.
If the protection is comfortable and well fitted, workers’ acceptance and willingness to wear them properly will be enhanced.
Part Two: Earmuffs
Contrary to popular belief, earmuffs typically offer lower Noise Reduction Ratings (NRR) than earplugs. In fact, the highest rated earmuffs on the market today have an NRR of 30 dB, as opposed to 33 for the highest rated earplug. This seems counter-intuitive, since earmuffs are bigger and heavier, but it’s an earplug’s ability to fully block the ear canal that really attenuates sound. Still, earmuffs offer a high degree of comfort and usability, and most products with an acceptable NRR level will block most harmful noise, provided they are fitted and worn correctly.
Passive earmuffs, made from a wide range of materials, block sound using just the foam and other components of the earcup. Headbands can be plastic or metal. Some users feel that metal is sturdier and offers the best wear, while others prefer plastic headbands because they hold their shape with more integrity. Stretching earmuff bands out to make them more comfortable, decreases the level of protection the product can provide. Earmuffs should fit snuggly and securely, creating a tight seal around the ear, and not slip around.
Special application styles available for passive earmuffs include: Cap-mounts, designed to be fitted on hard hats; neckband earmuffs can be worn around the back of the neck so users can wear them with other safety gear; and multi-position earmuffs can be worn with a band behind-the-head, over-the-head, or under-the-chin. Folding earmuffs allow easy storage and portability, and optional carrying cases and belt clips help keep earmuffs at the ready throughout the workday.
Uniform Attenuation Earmuffs
A fairly new product development is the uniform attenuation earmuff. These earmuffs not only block noise, but they employ advanced acoustic technologies to manage incoming sound providing additional benefits. By more uniformly attenuating several key octave bands (250Hz – 4KHz), protection is enhanced. Users can hear voices and warning signals more naturally.
Electronic earmuffs not only block sound, but also modulate that sound through electronic means. Itw can be very simple—like amplifying ambient sound so users can better hear normal sounds in their environment—or more complex, such as offering two-way communication. The market for electronic earmuffs is much smaller than for other earmuff products, though some manufacturers are investing heavily in it. Prices can range from $60 for a basic radio earmuff to $300 or more for high-end aviation headsets. To block noise, most standard electronic earmuffs will probably do fine. However, if you have workers in boring or repetitive jobs, you may find job satisfaction can be improved with an AM/FM radio earmuff, or products that can connect to a CD or an MP3 player.
Providing More Than NRR
A number of studies have shown that despite improvements in the effectiveness and availability of HPDs and despite regulations mandating their use, the incidence of job-related, noise induced hearing loss continues to rise. The reason for this can largely be attributed to the human factor: our species seems to have an innate reluctance to obey the rules, even when they are good for us. Selecting HPDs with comfort, convenience, and communication without inteference will improve worker safety, improve regulatory compliance, and may very well improve productivity and worker morale as well.