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Addressing Noise in the Workplace
Excessive noise levels are found in a many workplaces and can cause problems other than just hearing loss. They also can create dangerous situations, such as an inability to hear warning signals, a decline in one’s ability to communicate with fellow employees, and a decrease in one’s ability to concentrate. Excessive noise has even been found to cause stomach problems and high blood pressure.
In some cases, excessive noise can be controlled through engineering or administrative controls. However, engineering and administrative controls are not always possible, and therefore hearing protection devices may be needed to properly protect employees.
There are many occupational noise sources. They include, but are not limited to, manufacturing equipment, power generators, use of motor vehicles or heavy equipment, aircraft noise, hammering, jackhammering, sawing, drilling, emergency vehicle sirens, and construction sites. All of these noises can easily exceed safe levels and, in time, result in hearing loss.
Hearing loss usually occurs over an extended period of time and may not be noticed by an employee. Humans do not become acclimated to noise. Although some losses can be temporary, once a loss become permanent, you will not recover any hearing.
Determining whether or not engineering controls, administrative controls, or hearing protection devices are necessary is a three-step process:
- Recognizing that a noise problem may exist.
- Evaluating the extent of the problem.
- Controlling the problem.
Recognizing the problem can be as simple as being unable to properly communicate with another worker a few feet away. However, it can also be very complicated. For instance, a work site might have many different machines contributing to the overall excess of noise; there may be acoustic cues associated with determining whether a machine is operating properly or even sounds from some machines that appear to be the most dangerous source, but in fact that may not be the case.
Properly evaluating the problem requires a qualified professional to perform the measurements and analyze the results. For general industry, the federal OSHA standard on Occupational Noise Exposure is 29 CFR 1910.95. It sets the permissible exposure limit (PEL) at 90 dBA as an eight-hour time weighted average (TWA). When levels exceed 85 dBA as an eight-hour TWA, 29 CFR 1910.95 requires the employer to institute a hearing conservation program. This entails annual audiograms, training, providing a choice of hearing protectors to the employees, and various other elements.
One should refer to this regulation for details. Employers also should look to see whether their state has its own program. State regulations will be at least as stringent as the federal regulation. They can be stricter and possibly have additional requirements.
Controlling the problem can be accomplished using administrative controls, engineering controls, or hearing protection devices. Generally accepted practice dictates that administrative and engineering controls be exhausted before hearing protection is used. However, if neither administrative controls nor engineering controls can reduce the noise level below the limit, hearing protectors must be worn. There are many situations when the only practical means of noise control is through the use of personal protective equipment (PPE).
When hearing protection is required, it is sometimes difficult to ensure that employees are using the device properly. This is often due to a lack of training, a misuse of the protection device, or other program compliance issues. A good hearing conservation program can avoid many of these problems.
Until employees understand the hazards associated with noise and become acclimated to the use of the hearing protection devices, wearing hearing protectors might seem like a nuisance. Use of hearing protectors can preserve an employee's hearing when noise cannot be engineered out of the workplace. The most common complaints by employees are that the protectors are uncomfortable, hot, cause headaches or ear aches, and create a situation where the employee cannot hear warning signals or fellow workers. All of these objections can and must be overcome to protect the employee's hearing. These objections can be overcome by implementing a program that chooses the appropriate protector for the situation, provides training for the employee, and requires periodic compliance checks.
If compliance is lacking, the employer should investigate the cause by asking employees why they are not wearing the assigned hearing protection. The employees may not fully understand the need for hearing protection, or the situation may simply require that another hearing protector with similar attenuating characteristics be provided. If the employees do not want to wear the hearing protector, then disciplinary action might be appropriate, but only as a last resort.
Hearing Protector Selection
Many types of hearing protectors are available to meet employee needs in terms of both compliance and user acceptance. For example, ear plugs have varying NRRs for different situations and come in many different colors and shapes. Selecting an appropriate device that does not overprotect the user can alleviate concerns about not being able to hear warnings and fellow employees. Adequate training and allowing the employee to get used to the device also can help.
Choosing the right hearing protector requires careful consideration. Many work sites are predominated by low frequency noise. Ear muffs can be very helpful in these types of environments. Bands and muffs also can be useful in situations that require the employee to periodically leave a noisy environment, thus causing the employee to remove the device several times throughout the day.
If the employee has to wear a hearing protector for extended periods of time, ear plugs are often preferred. They are comfortable and require little maintenance. Another very important factor is how the hearing protector interacts with other PPE, such as hard hats, eye protection, and welding hoods.
Last but not least, one of the most important things for a successful program is to get employees to feel like they are being included in the decision process of developing the program. This must be done with the appropriate training and motivation and also by impressing upon them that once hearing is lost, it does not come back.
This article originally appeared in the March 2015 issue of Occupational Health & Safety.
Jeffrey Birkner, Ph.D., CIH, is VP-Technical Services for Moldex-Metric, Inc., a leading manufacturer of hearing and respiratory protection equipment. For more information, visit www.moldex.com.