Hearing Protection
Various types of hearing protection are shown.
Date Posted: 05/11/2024
According to the National Institute for Occupational Safety & Health (NIOSH), approximately 22 million workers yearly are exposed to hazardous work-related noise. As a result, occupational hearing loss is one of the most common work-related illnesses in the U.S. Noise is unwanted sound that can affect your job performance, interfere with communication, startle you, and disrupt your concentration leading to incidents. In addition, the psychological effects of noise include annoyance and disruption of attention. Ideally, engineering design or limiting the time a worker is exposed to noise will control hazardous noise exposure. However, this may only sometimes be feasible, especially in industrial facilities or construction sites. In situations where the ideal forms of control are not viable, Personal Protective Equipment (PPE) can be used to reduce noise levels at the ear. In addition, hearing protection can be provided as earplugs or earmuffs.
A decibel scale is shown.
How do You Control Your Exposure to Hazardous Noise at Work?
The consequences of failing to protect your hearing may take years to show up. Prolonged exposure to noise exceeding 85 decibels (dB), about the same loudness as a vacuum cleaner, can cause permanent hearing loss by damaging the microscopic hair cells inside your ears. Methods to control the noise that can cause permanent hearing loss include:
Engineering Controls
Engineering Controls involve modifying or replacing equipment or making changes at the noise source or along the transmission path to reduce the noise level at the worker's ear.
Choosing low-noise tools
Maintaining and lubricating equipment
Providing barriers between the noise source and the worker o Enclosing or isolating the noise source
Administrative Controls
Administrative Controls are changes in the workplace that reduce or eliminate worker exposure to noise; or operating noisy machines during shifts when fewer people are exposed.
Limiting the amount of time and exposure to hazardous noise.
Providing quiet areas where workers can gain relief from hazardous noise sources
Restricting worker presence to a suitable distance away from noisy equipment.
Hearing protection devices (HPDs)
HPDs, such as earmuffs and plugs, are considered an acceptable option to reduce exposure to noise following engineering and administrative controls.
When Do You Need Hearing Protection?
Hearing protection is essential when noise exposures can't be controlled at their source or sufficient distance between you, and the source cannot be achieved. Both earplugs and earmuffs provide a physical barrier that reduces inner ear noise levels inner ear and prevents hearing loss from occurring. However, people often resist wearing these or misuse them. When exposed to noise, 85 dB(a) or greater averaged over 8 hours. Noise at and above this level is considered hazardous.
Some signs that you should be wearing hearing protection include:
If you must raise your voice for someone 3 feet away to hear you, the site is too noisy, and you need hearing protection. You need hearing protection also if you’re operating on or near noisy equipment.
If you have roaring or ringing noises in your ears at the end of the workday, you are probably being exposed to too much noise.
If speech or music sounds muffled to you after you leave work, but it sounds clear in the morning when you return to work, you are exposed to noise levels causing temporary hearing loss. In time, this can become permanent if you do not take care.
Choosing the Right Hearing Protection
Sound is measured in decibels. Each hearing protection device has a Noise Reduction Rating (NRR) in decibels (dB). To ensure you are not exposed to noise over the maximum safe exposure (85 dB over 8 hours), the NRR of the hearing protection device is matched with your level of exposure (loudness and duration of exposure).
For example, if you are exposed to 90 dB of noise and wearing earplugs with an NRR of 29, your actual noise exposure will be reduced to 61 dB. Alarms must be louder than ambient or surrounding noises and typically range from 90–110 dB. This is well within the range of hearing, even with hearing protection devices. Some alarms adjust according to the ambient noise to ensure they are 10 dB higher. Some protective devices also adjust according to ambient noises. If you need to hear subtle changes in the sound of machinery, this device can amplify low-level noises while decreasing dangerous noise levels. The four types of hearing protection devices are shown below:
Expandable Foam Plugs
Expandable foam plugs are made of a formable material that fits the shape of a person’s ear. To fit correctly, the plug must be rolled until it is thin enough to fit halfway into the ear canal. The main drawback is that it’s challenging to roll the plugs small sufficient to make them fit. As a result, a few manufacturers offer small expandable plugs.
Pre-Molded Plugs
Pre-molded plugs can be made of silicon, plastic, or rubber and come in various sizes. Although typically sold as pairs, you may need a different-sized plug for each ear to get the proper fit. In addition, plugs should seal the ear canal without being uncomfortable. The main advantages are that they are inexpensive, washable, reusable, and come in many sizes. They also reduce sound more evenly than expandable foam plugs.
Canal Caps
Canal caps are flexible tips (like pre-molded plugs) on a lightweight headband. The main advantage of canal caps is that they are quick to put on and take off and easy to store around the neck. This makes them ideal for intermittent use. However, they provide less protection than either plugs or earmuffs.
Earmuffs
Earmuffs have rigid cups with soft plastic cushions that seal around the ear to block noise. Easy to use, they block out noise by completely covering the outer ear. Some styles adjust to job-site noise. They are expensive but worth it, if necessary. However, some users find earmuffs hot and heavy in specific environments. They also don’t work well for those with heavy beards, sideburns, or glasses, which may break the seal of the earmuffs and allow noise in.
