Exposure to loud and persistent noise negatively impacts workers at a higher rate than many imagine. Sounds at or above 80 decibels are considered loud enough to cause some level of hearing loss, and millions of people perform tasks under such conditions.
According to the Centers for Disease Control and Prevention, upwards of 12 percent of workers struggle with hearing issues, 8 percent deal with tinnitus, and more than half fail to wear noise-reducing personal protective equipment. Access to safety information and more stringent company policies around occupational hearing loss prevention are sorely needed.
Industries and Tasks that Require Occupational Hearing Safety Protections
One of the underlying reasons that so many workers fail to practice occupational hearing safety stems from what appears to be low-level noise. Workers who are exposed to noise of around 85 decibels may be quick to adjust and shrug it off. Rather than putting on uncomfortable headsets and ear coverings, they attempt to tough it out and just talk a little louder.
What employees and employers may not grasp is that a mere 80 decibels over a shift has a harmful effect on hearing. Although the blaring sound of a police siren is often used as an example, much quieter equipment runs around 80 decibels.
For instance, vacuum cleaners, automobile traffic, household garbage disposals, the dinner shift at a busy restaurant, window air conditioners, hair dryers, and many others produce 80 decibels.
By that same token, snowblowers (85 decibels), power tools (90 decibels), dance clubs (90+ decibels), sporting events (110 decibels), and ambulances (130 decibels) are all noises that workers tend to practice inconsistent occupational hearing safety measures. These rank among the many jobs where hard-working people sometimes fail to follow occupational hearing loss prevention standards.
- Airport Ground Personnel
- Carpenters
- Masons & Mason Tenders
- Landscapers
- Musicians, DJs, & Nightclub Staff
- Live Music Audio Engineers
- Manufacturing & Power Plant Workers
- Members of the Military
- Truckers and Other CDL Holders
- Heavy Equipment Operators
- Agricultural Machinery Operators
- Commercial Cleaning Crews
- Warehouse & Loading Dock Staff Members
- Loggers and Sawmill Workers
It’s difficult to imagine a high school or college coach wearing noise protection during a big game. Still, the facts suggest that employing occupational hearing safety gear is in their best interest. According to the Occupational Safety and Health Administration (OSHA), exposure to 85 decibels over an 8-hour period calls for personal protective equipment to minimize the impact of noise.
It’s also essential to keep in mind that 85 decibels over eight hours is the minimum permissible exposure limit (PEL) established by OSHA. The CDC notes that 20 percent of workers who are tested for noise-related hearing loss suffer significant impairment. And 13 percent demonstrated hearing loss in both ears.
How Does Hearing Loss Occur?
Occupational hearing loss typically happens when workers are exposed to noise at or above 80 decibels for extended periods of time. In some instances, damaged hearing can be traced to low-humming noises. In others, it involves extremely sound sounds generated at various intervals.
When the auditory system experiences excessive types of noise, the following occurs.
- Sensorineural Hearing Loss: Cells connected to hair follicles are responsible for converting the sound. They transform noise into an electric signal the brain recognizes. The fragile hair cells that reside in the inner ear can be overwhelmed by loud and persistent noise. Once damaged, they can no longer do their job of translating sound into a recognizable signal for the brain to interpret.
- Conductive Hearing Loss: This type of hearing impairment stems from damage to the middle ear. Extremely loud and persistent noise can damage fibers and membranes in the middle ear. This makes it difficult for sound to travel through the ear canal.
- Eardrum Damage: A sudden burst of noise that reaches 150 decibels can rupture a person’s eardrum. People who use jackhammers, fire truck sirens, and chainsaws, among others, could suffer an eardrum rupture and permanent hearing loss.
For many who live with work-related hearing loss, the daily sounds are no longer as vibrant. Favorite songs, bird chirping, and the rustle of children playing become muffled. A reported 50 million Americans struggle with the piercing, high-pitched ringing commonly known as tinnitus.
This chronic condition has been linked to anxiety, sleeplessness, depression, cognitive decline, and makes communication and concentration difficult. Unless safety managers improve their occupational hearing loss prevention efforts, everyday people will continue to live with conditions that diminish their quality of life.
What is Double Hearing Protection?
Double or dual hearing protection is as straightforward as the term indicates. It involves wearing two types of hearing-related personal protective equipment at the same time. One of the most popular ways to achieve double hearing protection consists of putting in commercial-grade ear plugs and covering the entire ear with a set of muffs.
In some cases, practicing dual hearing protection is driven by the ability of the individual products, aka Noise Reduction Rating (NRR). If a product only adequately covers 30 decibels, a worker — theoretically speaking — needs to pick up another 50 decibels or more of protection to comply with OSHA standards.
These personal protective devices must also work seamlessly with products, such as hooded coveralls, hard hats, and other disposable clothing and head protection gear. OSHA publishes a formula that helps employers know how and when to wear double hearing protection.
- Determine the decibels and PEL an employee is exposed to without hearing protection.
- Subtract 7 decibels from the NRR of each hearing protection device, as listed on the product.
- Take that figure and subtract it from the first metric, i.e., unprotected noise exposure.
The sum provides a baseline to select one or more occupational hearing safety products to meet or exceed the noise reduction required to safeguard valued employees.
What is a Noise Reduction Rating (NRR)?
The Noise Reduction Rating (NRR) is a system for testing hearing protection devices in a laboratory setting. A number is assigned, following rigorous testing, that correlates with the decibel level it can protect against. Higher NRR ratings indicate the product has the capacity to be used in louder situations.
The concept of a Noise Reduction Rating was developed by the Environmental Protection Agency (EPA) and later adopted by OSHA when it put the Hearing Conservation Amendment (29 CFR 1910.95) into effect.
While NRR remains a fundamental element of OSHA hearing regulations, there are other considerations as well. Employers who stockpile disposable personal protective clothing and equipment are tasked with onboarding hearing solutions that are pragmatic and comfortable. It’s no secret that workers are less likely to don overly tight and cumbersome items that cause sweating and discomfort.
When to Wear Double Hearing Protection
It’s important for employers and workers to take a common sense approach to knowing when to wear double hearing protection. The first step is to acknowledge that an environment exceeds OSHA PEL rates or may present sudden loud bursts of noise.
Calculate the decibels and measure that figure against the heart-protective products that make sense in your workplace. Follow the OSHA formula and determine whether single protections are adequate. If earplugs or canal caps alone do not suffice, add muffs to the equation and reassess.
These are occupations in which double hearing protection practices are typically necessary.
- Fireworks Display Professions
- Fire Engine Drivers and Occupants
- Loggers Who Use Chainsaws
- Jackhammer Operators
- Nightclub DJs and Live Music Sound Engineers
- Airport Flight and Ground Crews
- Heavy Machinery Operators
- Farm Tractor Operators
Safety managers would be well-served to choose disposable personal protective clothing and equipment that fit comfortably when doubling up on noise-reducing products.