Welding, cutting, gouging, and metal work all expose workers to high levels of noise that, over time and exposure, can damage a worker’s hearing and even lead to permanent hearing loss. niosh (national institute for occupational safety and health) recommends that workers shall be required to wear hearing protectors when engaged in work that exposes them to noise that equals or exceeds 85 dBA as an 8-hour TWA (Kardous et al., 2016).

Today, there are several different styles and types of hearing protection to choose from that meet OSHA and EPA standards. Ear protection uses noise reduction rating (nrr) in dB (decibels), which assigns a number rating to show by how many decibels the ear protection selected reduced noise by. For example, earplugs may have an NRR of 27 dB, and an average busy street may have an NRR of 70 dB. So, if a wearer uses earplugs on a busy street, the noise is then reduced to 43 dB. Which is well within a range for a person to be exposed to for multiple hours a day without risk of hearing loss or injury (Moniz, 2015, pp 19-20).

• DANGER: 120 – 130 dB Once a noise reaches over 85 dB (approximately the level of a vacuum), damage to your hearing may begin.
• HEARING PROTECTION NEEDED: 97 – 115 dB After this, every 3dB increase in sound halves the length of time that your ears can handle the noise before damage starts.
• HEARING PROTECTION NEEDED: 94 – 91 dB You can only listen to personal music players (PMPs) for approximately 3.75 minutes on a high volume before it starts to damage your hearing.
• SAFE: 85 – 55 dB The lower the volume, the longer you can safely listen for.

Earplugs

Canal caps, pre-molded reusable plugs, and expandable foam plugs are all devices that are inserted into the ear itself. They may be reusable with proper cleaning and storage, or they may be single-use. Earplugs fit easily and comfortably under a welding hood with other PPE such as safety glasses and a respirator. Earplugs also protect the inner ear from sparks, and molten metal spatter that occurs with several welding processes. When conducting hot work such as cutting, welding, or grinding, not only do ear plugs provide the necessary protection to hearing, but they will also prevent those hot droplets of steel from entering the ear canal. Reusable earplugs can be used for 2-4 weeks and should be washed with warm soapy water and left to dry. Do not clean your earplugs with alcohol or chemical-based solvents.

Earmuffs

Exposure to loud noises can cause permanent damage to the ears and lead to partial or complete hearing loss. While earplugs are an excellent option for protection, there are also several different types of earmuffs or over-the-ear hearing protection. If a workplace or job site exposes a worker to eight hours or more of noise meeting or exceeding 85 decibels, then noise protection is required. OSHA regulation 1910.95 App B goes over Noise Reduction Rating or NRR. This rating is a calculation but also a measurement that earplugs and earmuffs are rated at so that an individual can know if their hearing protection is adequate enough for the noise they are being exposed to. The higher the NRR number, the greater the noise reduction the ear protection provides.

For example, earmuffs used on a shooting range may be rated for approximately 37 dB, whereas earmuffs used for household equipment like lawnmowers may be rated at 20 dB. It’s not always about how loud a specific situation is, but about how long a person is exposed to the sound if it’s steady or a sudden blast like a gunshot, and how often a person is exposed to this sound.

Noise canceling

In addition to providing inner and over the ear protection, there are also features such as noise canceling headsets. These are generally not acceptable workplace hearing PPE as they cancel out noises that may be necessary for a user to hear to work safely such as the sound of a forklift coming around the corner, a truck backing up, or a call for help. Noise-canceling headphones or ear protection are not OSHA-approved. While they may be a great product for work in busy work environments like an office or to cancel out distractions to help a student study, these devices cancel out too much noise for a job site environment.

Attributions

1. Figure 3.7: Earplugs – single use and reuse by Bill Ebbesen is released under CC BY-SA 3.0
2. Figure 3.8: Peltor earmuffs by JiriMatejicek is released under CC BY-SA 4.0
3. Figure 3.9: Active Noise Reduction by Marekich is released under CC BY-SA 3.0