Safe and Sound
By Jean Lian
Communication relies on our ability not only to speak, but also to hear. Proper hearing protection is indispensable to protect the auditory faculties of those working in environments with high noise levels.
Manufacturing, construction, food processing and oil and gas are among the industries that typically need hearing protection, says Chris O’Donnell, product champion for hearing and lens-cleaning products with Radians Safety in Memphis. Other workplaces, like nightclubs and some restaurants, also have noise hazards.
One common myth is that hearing-protection devices interfere with the user’s ability to communicate. “If you have an earplug that is inserted well, you are going to hear that patron talk to you clearer than if you didn’t,” says Bev Borst, an advanced development specialist for 3M Canada in London, Ontario. She explains that earplugs reduce noise and allow one to hear conversations better.
A workplace with hazardous noise levels needs to do a noise assessment to determine whether hearing protection is needed. “Sound-level measurements have to be done if you suspect noise, any time the noise changes and on a regular basis after that,” says Borst, whose company offers a wide selection of hearing-protection devices.
A matter of type
There are essentially four types of hearing protection. The most popular is disposable earplugs made of polyurethane foam, which typically have a noise-reduction rating (NRR) ranging between 29 and 33 dB, O’Donnell says. The second type is reusable earplugs made of silicone or latex-type material, followed by custom-moulded earplugs, which are manufactured through a process that involves injecting a material to fill the ear cavity and using the solidified material to custom-make the device. The fourth type is earmuffs, which often come with an NRR from 22 to 25 dB.
Radians offers a wide range of hearing-protection products that include earplugs — both disposable and reusable — and passive and electronic earmuffs.
According to O’Donnell, Radians is one of four manufacturers that make foam earplugs in the United States, Canada and Mexico. Disposable earplugs typically cost around 10 cents a pair, while the reusable ones hover around a dollar a pair. Earmuffs are costlier, at $10 and above, while custom-moulded devices can cost anywhere from $80 to $180.
Radians recently introduced two new products, one of which is a multi-coloured earplug that was launched in March. “Some companies like multi-coloured earplugs because it allows the safety director, plant manager or supervisor to see the earplug in the ear better,” O’Donnell says. Also in the works are two new electronic earmuffs, one of which has the ability to do Bluetooth.
More consumers today are using hearing protection than in the past, observes Claudio Dente, president of Dentec Safety Specialists Inc. in Newmarket, Ontario. Industries are also adopting more aggressive hearing-protection programs. “We are seeing products, both in the earplugs and the earmuffs, that are significantly more comfortable that also have higher noise-reduction rating and attenuation,” he adds.
Dentec Safety offers a family of hearing-protection devices that includes earmuffs worn over the head as a headband, earmuffs attached to a hardhat and earplugs in different formats. Reusable earplugs are available in both sized and universal-sized versions, while disposable earplugs are available in both polyurethane as well as polyvinyl chloride foam with a material that stays soft in the ear canal for comfort.
Another trend, which has been around for eight years, is the fit testing of hearing-protection devices. This trend has become more entrenched since the CSA standard recommended fit testing as a good practice, Borst notes.
According to Eric Moreno, a segment marketing manager with MSA North America in Cranberry Township, Pennsylvania, personal protective equipment used above the neck should be from the same brand or manufacturer for enhanced compatibility as well as optimal fit and comfort.
MSA creates and manufactures products that comply with the most up-to-date ANSI and CSA standards. Within MSA’s line of passive earmuffs are two product types: SoundControl® and left/ RIGHT® Hearing Protection. SoundControl SH is a compatible earmuff designed to fit snugly into the new accessory slots on the MSA V-Gard® Slotted Hard Hat.
The MSA left/RIGHT Ear Muffs, on the other hand, have dedicated right and left ear cups that are tailored to fit ears of all shapes and sizes for enhanced comfort and protection. “Left/RIGHT earmuffs are designed for a truly personal fit,” Moreno adds.
Hearing protection should be worn 100 per cent of the time at work. “If you are working an eight-hour shift in a noise-hazardous environment, you should have hearing protection on,” Moreno stresses.
Given the wide array of products, fit, comfort and noise reduction are three key factors that need to be considered when choosing a hearing-protection device. “You need a selection in order to fit everyone’s ear. They have to be comfortable and have the right level of protection,” Borst advises.
And “right level” are the key words. “People overprotect their employees, which is also a problem,” Dente cautions. “You should select a hearing protector that reduces the sound to below the allowable limit. If you go too far below that amount, it will and can cause other issues,” he says, citing isolation that occurs when a worker cannot communicate with his or her peers. Overprotection also poses a threat to personal safety. “The user will not be able to hear a machine make noise that could indicate it was going to malfunction and cause injury or harm to the operator,” he adds.
Most general industry operates at around 90 dB over an eight-hour day. If a worker is wearing a hearing protector with an NRR of 35 dB, that reduces the sound level to 55 dB. “At 50, you can hardly hear anything,” Dente says, illustrating that an office with people talking and the noise of the ventilation hovers at around 65 dB.
Dente cites his company’s Nextera over-the-head band earmuff and the SoundStar earmuff as examples. “While the Nextera has an NRR of 30 and the SoundStar has an NRR of 25, one would think the Nextera is the better choice. But when you compare the specific frequencies, you will see that the SoundStar will provide more than enough protection in the majority of the workplaces,” Dente explains, stressing that it is important for end users to know not only the intensity of the sound measured in decibels, but also the frequency measured in hertz. “When they know this, they can select the best protector and most often a more economical and more comfortable protector for the application.”
Considering that noise-induced hearing loss is irreversible, reduces productivity and causes physical and psychological stress, protection and prevention are a worker’s best defence against excessive noise.
Jean Lian is the editor of OHS Canada.