Work-related hearing loss affects 30 million American workers â€” or 25 percent of the workforce â€” who are exposed to hazardous noise on the job. According to studies cited by the American Industrial Hygiene Association (AIHA), workers in high-noise environments typically lose more time due to accidents and are less productive than those exposed to lower noise levels.
The good news is that occupational noise-induced hearing loss (ONIHL) is 100 percent preventable when proper measures are implemented as part of a workplace safety program.
The distance from the sound source, the level of decibel exposure, and the duration of exposure are critical factors to consider when evaluating risk. The louder the sound, the shorter the period of time in which noise-induced hearing loss (NIHL) occurs. NIHL can result from a one-time impulsive noise exposure or from continuous, long-term exposure to sounds at or above 85 decibels. (Long-term noise exposure to less than 75 decibels is unlikely to result in hearing loss.)
OSHA mandates that employers implement an ongoing hearing conservation program whenever noise exposures equal or exceed an 8-hourtime- weighted average sound level (TWA) of 85 decibels (29 CFR 1910.95). Noise exposure for a single worker over a period of time is measured and calculated with a noise dosimeter.
Employers must first try to diminish workplace noise by implementing engineering controls to reduce exposures. If these are not effective, employees must use hearing protection devices (HPDs) to reduce exposure to safe levels.
OSHA requires that employers:
- Provide hearing protection at no cost to all employees and onsite guests and ensure that it is worn.
- Give employees the opportunity to select from a variety of suitable hearing protection options.
- Offer annual training in the use and care of all HPDs.
- Oversee the initial fitting and supervise the correct use of all HPDs.
According to OSHA, hearing protectors must adequately reduce the noise level for each employee’s work environment. Most employers use the noise reduction rating (NRR) that represents the hearing protector’s ability to reduce noise under ideal laboratory conditions. However, in order to apply the NRR to real-world situations, the EPA is revising this more-than-30-year-old rating system to provide improved guidance when determining the protection provided by hearing protection products. The new standard is expected to offer a numerical range of protection rather than a single number, as with the current standard.
HPDs should be selected to reduce the environmental noise to safe levels as directed by OSHA and not to eliminate all sound entirely. This type of “overprotection” would be impractical as well as dangerous because employees must be able to hear sounds to perform their jobs safely and effectively.
Hearing protectors are designed to reduce the amount of sound entering the delicate regions of the inner ear where hearing damage can occur. There are three common classifications:
1. Earplugs fit in the outer ear canal. When inserted properly, they block sound with an airtight seal and must be snugly fitted to seal the entire circumference of the ear canal. They are available in a variety of materials, shapes, colors, and duration of use (single use vs. reusable). An improperly-fitted, dirty or wornout plug will not seal and can irritate the ear canal.
2. Earbands also fit in the outer ear canal but are held in place with the tension of the band.
3. Earmuffs fit over the entire outer ear and are typically held in place by an adjustable headband. Since wearing earmuffs with other PPE such as safety glasses or hard hats can be a challenge, some of the newer hearing protection products can be independently secured to the ear without these high-pressure bands.
Comfort, convenience and compatibility
Hearing protection is only effective when employers and employees appropriately select, wear and care for these items. According to the National Hearing Conservation Association (NHCA), the most important factor in hearing protector selection is finding a comfortable device that an employee will wear correctly 100 percent of the time during exposure to harmful noise. Or, as stated in Oregon OSHA’s guide to hearing protection: “Focus on the three Cs: comfort, convenience and compatibility. Employees won’t wear hearing protectors that are uncomfortable or difficult to use or that interfere with their work.”
As with other forms of PPE, hearing protection devices are continually evolving. Recent designs feature a twopart system consisting of a reusable ear-clip chassis and removable foam ear pad to block sound without intruding into the sensitive ear canal. Many newer options work with other forms of head protection, such as safety eyewear, respirators, hard hats and hooded apparel.
Select hearing protection products that:
- Offer easy insertion and removal.
- Provide flexibility and conformity to the ear canal opening.
- Offer a hygienic fit and seal inside the ear canal.
- Are lightweight.
- Stay securely in place without creating pressure inside the ear canal.
- Provide reliable features for shift-long comfort.
- Hygienic storage solutions for devices when not in use.
- Options with and without cords to fit individual preferences.
- The ability to be used in conjunction with other head protection PPE.
Employee training is a crucial element of any hearing conservation program. According to OSHA, workers who understand the reasons for hearing conservation programs and the need to protect their hearing will be more motivated to wear hearing protectors and take audiometric tests.
OSHA states that “employers must train employees exposed to TWAs of 85 decibels and above at least annually in the effects of noise; the purpose, advantages, and disadvantages of various types of hearing protectors; the selection, fit, and care of protectors; and the purpose and procedures of audiometric testing. The training program may be structured in any way, with different portions conducted by different people and at different times, as long as the required topics are covered.”
Hearing is that unique sensory gift that allows us to appreciate sounds that matter to us, whether in our personal lives or on the job. A first step to increased compliance is to make sure hearing protection products are comfortable, easy to insert and remove, and integrated with other forms of PPE.
For more information, visit www.osha.gov, www.cdc.gov/niosh, www.epa.gov, www.hearingconservation.org and www.aiha.org.