Noise levels not only change over time, they also vary in different areas of the facility — often so widely that different hearing protection is required for various work areas or, occasionally, various tasks in the same work area. Recognize “noisy spots” and periodically take readings in these problem areas. Repeat monitoring whenever a change in production, process, equipment or controls increases noise exposures to the extent that additional employees may be exposed or hearing protection device attenuation is inadequate. At a minimum, conduct annual assessments — or even more frequent assessments in previously identified “noisy spots.”
Remember that the first priority is to reduce noise levels through engineering or administrative controls. Personal protective equipment (PPE) is required if the noise remains above permissible levels after other measures to reduce or eliminate noise have been instituted and during the time when controls are being implemented.
It is incumbent upon safety professionals to educate employers and employees alike to avoid commonly made mistakes, such as:
- Misjudging noise levels
- Choosing a hearing protector based solely on attenuation characteristics
- Selecting equipment that is inappropriate for the noise level
- Providing inadequate training and inadequate access to protection for visitors as well as employees
Noise levels in a facility may have been measured last year at a level below the 85 dBA (A-weighted sound level for an eight-hour period) action level that requires hearing protection and annual audiograms be made available to employees. Today’s noise level readings may reveal that aging machinery, new equipment or process changes have increased noise to harmful levels. It’s important to clarify the requirements for assessing noise levels — not just once, but on a periodic basis.
If it is determined that PPE is mandatory (above 85dBA), a variety of hearing-protection choices should be made available to employees. It is possible for different versions of just one type of hearing protection, such as disposable earplugs, to fulfill the needs. However, the same type may not be suitable for every employee so a combination of types, such as disposable plugs, reusable plugs and earmuffs may be better.
The goal is user comfort as well as protection. If comfortable, employees will more likely wear hearing protection properly and at all times that they are required.
The higher the NRR grade or class rating, the higher the attenuation obtained in a laboratory, but not necessarily the protection afforded in the workplace. Actual protection is a function of how well the protectors fit the individual, whether they are comfortable and whether they are worn correctly and continuously when in the noisy environment.
Match protection to noise level
Once noise levels are assessed, employees must select protection appropriately matched to noise levels in their specific work areas. For example, the frequency of the noise spectrum may influence the choice between a plug and a muff. A muff is generally better at attenuating high and mid-range frequencies and a plug better at low frequencies.
Most employers do not know the frequency of the noise in their workplace, so the NRR grade or class rating of the hearing protectors provides a guideline for judging which level of protection is best matched to the measured noise levels.
Over-protection occurs when the hearing protector’s NRR grade or class is too far above what is needed to reduce the noise to less than the required 85dBA average. Choosing a protector that may reduce the noise to a level below 70dBA may cause the wearer to miss warning signals, general communication, and other sounds necessary to safe and efficient job performance.
Training and access
Putting in earplugs or using earmuffs is not a complex task. However, that doesn’t mean that training isn’t necessary. In a short motivational training session, employees should be made aware of noise levels in their work areas and the damage that could occur over time if they do not wear hearing protection. Employers should make it clear that refusal to wear hearing protection potentially can result in dismissal, since failure to wear the protector is a violation of federal law and the company could otherwise incur serious liabilities. Training on how to fit hearing protectors and how to care for them will ensure that protection is effective and comfortable. The annual training program also should include an explanation of audiometric test procedures as well as the purpose of annual audiometric testing.
Hearing protectors should be readily available to all employees. At a minimum, disposables should be placed in wall or tabletop dispensers just outside the doors to noisy areas. For employees provided with their own earmuffs or reusable earplugs, a designated storage place in or near the work area will make access to hearing protection convenient. Corded versions or muffs designed to attach to hard hats help solve special accessibility concerns.
Protect visitors who enter work areas with high noise levels with required protection based on the same criteria as that for employees in the same workspace. Although most hearing loss is gradual, very loud noise can cause immediate short-term, and sometimes irreversible, hearing loss. Employers should design a short program to educate visitors on required hearing protection.
Good hearing protection practices
In addition to avoiding the cost of safety violations or the possibility of claims for hearing loss, a company’s investment in hearing protection for employees and visitors provides other indirect benefits. These include avoiding the potential cost of accidents that might occur because an employee with as yet unrecognized and un-remediated hearing impairment missed a warning signal or misunderstood instructions.
Offering good hearing protection engenders loyalty to employers who show concern for their employees’ health. It also reduces the cost of sick days and training new workers when noise-induced stress, headaches and burnout contribute to excessive absenteeism and high employee turnover.
The cost of providing hearing protection to employees is minimal compared to the costs of negligence or uneducated attempts to do the right thing. Avoiding the cost of mistakes requires just a little effort to develop a short but effective hearing protection program.