Choosing the right earmuffs

Today’s earmuffs provide far more than just hearing protection. Benice Deal and Patricia Calaby report for Safety First.

EARMUFFS occupy the higher end of the price scale for hearing protection devices (HPDs), ranging from $12 to $250 or more.

The basic categories include passive earmuffs, which rely solely on the sound blocking quality of the earmuff itself, and electronic earmuffs which utilise sophisticated electronic devices to block or modulate noise, and offer additional specialty features.

But those options come at an additional cost, so it is best to understand the noise protection needs of the wearer before recommending a particular earmuff.

Passive earmuffs

Passive earmuffs are made from a wide range of materials and are what most people think of as an earmuff. They block sound using just the foam and other components of the earcup.

When selecting a passive earmuff, there are several things to consider. 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.

Workers often stretch earmuff bands out to make them more comfortable, but this actually decreases the level of protection the product can provide, since the clamping force of the headband is one of the factors that ensures a proper fit.

Moulded plastic headbands are much harder to deform, as these materials have better elasticity and tend to snap right back when stretched.

Features promoting comfort and ease of use should also be considered, such as soft ear cushions, a good feel on the head, and headbands that adjust easily.

Earmuffs should fit snugly and securely, creating a tight seal around the ear, and not slip around. User instructions should also be intuitive and easy to follow for a proper fit.

There are also a number of special application styles available for passive earmuffs.

Cap-mounts, designed to be fitted on hard hats, are very popular in certain sectors. Neckband earmuffs can be worn around the back of the neck so users can wear them with other safety gear like welding helmets and face shields, and multi-position earmuffs can be worn with a band behind the head, over the head, or under the chin. These allow the earmuffs to be worn with other types of safety gear.

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

The uniform attenuation earmuff is a fairly new product.

These earmuffs not only block noise, they employ acoustic technologies to manage incoming sound in a way that provides additional benefits.

By more uniformly attenuating several key octave bands (250Hz — 4kHz), protection is enhanced. Users can hear voices and warning signals more naturally, and thus feel less isolated on the job.

Another promising new technology manipulates the flow of air within the ear cushion to reduce the vibration of the earmuff. This enables the muff to provide better attenuation performance in low frequencies.

A common problem with earmuffs is that they provide good protection on the high frequency end, but somewhat lower protection on the low frequency end.

Reducing the vibration of the earcup provides better attenuation in the low frequencies and enhanced overall attenuation without adding weight or size to the earcup.

Electronic earmuffs

Electronic earmuffs not only block sound, but also modulate that sound through electronic means.

These means 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.

Prices can range from $60 for a basic radio earmuff to $250 or more for high-end aviation headsets.

Selection criteria are similar to passive earmuffs, comfort, fit, and durability, with the additional need to evaluate the degree of sophistication needed for the application.

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.

Things get more complicated when people need to talk to each other.

There are a variety of products to provide these capabilities by incorporating boom microphones, two-way radios, mobile phones, and the like, although not all devices have the same connectors.

Customisation is often required to connect these devices to the earmuff, but many users with advanced applications find this to be an acceptable solution.

There are also some new simple and less expensive solutions to communication needs, including a new “push-to-listen” capability on some electronic muffs.

More than noise reduction

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 reasons 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.

Since no HPD can be effective if it is not worn, safety professionals should consider these four basic rules (the 4 Cs of hearing protection) when selecting products for their application:

Comfort: If a hearing protection device is not comfortable, it will not be worn.

• Convenience: If an HPD is not available when and where it is needed, or if it is difficult to use, it will not be used.

Communication: If a hearing protection device interferes with a user’s ability to understand instructions, or if he or she feels personally isolated on the job, or at risk due to an inability to hear warning signals, it will not be used.

Caring: If users do not understand and appreciate the need for hearing protection, they will not wear it.

Selecting HPDs with these concerns in mind will improve worker safety, improve regulatory compliance, and may very well improve productivity and worker morale.

Bacou-Dalloz Australia 1300 139 166.