Hearing protection devices (HPDs) help lower the noise exposure of workers by blocking out some of the sounds that enter their ears. They are most effective when used in conjunction with other methods of reducing exposure to hazardous noise such as Buy Quiet programs and noise controls. In an occupational Hearing Conservation Program (HCP), it is preferable to eliminate or decrease the severity of the hazard rather than to change the way people work or require workers to wear Personal Protective Equipment (PPE).
When controlling hazardous noise isn’t feasible, HPDs are essential. Offer a variety of HPDs that provide options for workers in terms of comfort, ease of use, communication and noise reduction (attenuation). Balance the need for noise reduction with the needs of individual workers and the work environment. This may mean that several types of hearing protectors are needed. Consider offering HPDs that are designed to help workers hear important sounds when there are concerns about communication and safety on-the-job.
Perhaps most important of all, teach your employees about their hearing protectors and how to properly use them. The attitudes and behaviours of your employees can be as important as the design of the HPDs themselves in helping to protect their hearing.
OSHA requires hearing protectors that are capable of reducing the noise hazard down to at least 90 dBA and, in some cases, down to 85 dBA or below to be worn. The protected exposure is the estimated TWA noise exposure of the employee after the protection provided by the HPD is taken into account. NIOSH recommends that all workers be provided with HPDs capable of reducing the protected exposure to 85 dBA or lower.
Given the large number of hearing protection options to choose from, employers should have no difficulty selecting a few HPDs from several categories which provide the right amount of noise reduction. Since ear canal sizes vary widely among groups of workers, be sure to include several sizes and types of earplugs. As the noise and work tasks are typically rather different, it can be helpful to include other options such as earmuffs, banded hearing protectors, and level-dependent hearing protectors that are designed to help employees maintain their ability to hear important sounds.
Since effective use of hearing protection is related to the skill and motivation of the wearer, providing training and education for employees is extremely important. Training should include information on the relative benefits of different styles of hearing protectors, how to select them, proper use and care, and when to replace them. To boost the impact of your training, be sure to include interactive learning methods, customise the content to your specific facility and discover what may motivate your employees to value their hearing enough to want to consistently wear hearing protection. Remind employees when, where, and how to wear hearing protection using signs and posters in noisy areas.
Each hearing protector is assigned a Noise Reduction Rating (NRR) by the manufacturer. This value, in decibels, is a description specified by U.S federal regulation of how much attenuation was achieved by a group of well-trained hearing protection users who wore the HPD correctly in a laboratory test. However, in the workplace, the noise reduction obtained by individual employees can vary widely and may be significantly lower or higher than the NRR value in individual instances. If the NRR is used to estimate typical workplace protection, 3M recommends that the NRR be reduced by 50% or in accordance with applicable regulations.
3M strongly recommends fit-testing of hearing protectors as the best method to validate that each employee is obtaining the proper level of protection. You can quickly measure and document the Personal Attenuation Rating (PAR) for each ear using a system such as the 3M™ E-A-Rfit™ Dual Ear Validation System. With this information, you can easily identify those employees who need additional training or who should be wearing a different size or style of the hearing protector.
OSHA, NIOSH and the National Hearing Conservation Association (NHCA) have endorsed hearing protector fit testing as a best practice. 3M strongly recommends fit-testing of hearing protectors as an indicator of the noise reduction obtained by individual employees.
Employers must make available a “variety of suitable hearing protectors” to all employees who have TWA noise exposures at or above 85 dBA, the OSHA Action Level (AL) for hearing conservation. The HPDs must be provided at no cost to employees and replaced as necessary.
Employers must provide training in the use and care of all hearing protectors provided to employees, ensure proper initial fitting and supervise the correct use of all hearing protectors.
Employers must ensure that hearing protectors are worn by employees who fall into any of these categories:
The employer must evaluate the HPD attenuation for the specific noise environment in which the protector is used using one of the methods described in appendix B of OSHA regulation 1910.95. Several options are allowed by OSHA for estimating the adequacy of the HPD to reduce the protected exposure of the employee to an allowable level.
Hearing protectors must reduce the employee’s TWA exposure to at least 90 dBA. However, for employees who have experienced a Standard Threshold Shift (STS), hearing protectors must attenuate the TWA to 85 dBA or below.
The adequacy of hearing protector attenuation must be re-evaluated whenever employee noise exposures increase to the point where the HPD may no longer provide enough protection. The employer must provide more effective protection as necessary.
Visit OSHA to learn more about hearing conservation requirements.
The effectiveness of HPDs is directly related to how well they seal out sounds in the environment. This is called the acoustic seal. Without an effective acoustic seal, excess sound leaks into the ear canal.
Some sounds are more difficult to block than others. For example, low-frequency sounds (bass on the musical scale) are more difficult to attenuate than high-frequency sounds (treble on the musical scale). To obtain good attenuation for both low and high-frequency sounds, hearing protectors must seal tightly in or around the ears with no leaks. When leaks occur, low-frequency sound can get through, causing a drop in the overall noise reduction. Suggestions for optimising noise reduction of hearing protectors:
Selecting hearing protection for your employees comes down to finding the right balance of comfort, ease of use, attenuation, and situational awareness.
Hearing protector fit-testing is recognised a best practice by OSHA, NIOSH, and other professional organisations. Although it is not a regulatory requirement, it has several benefits, and will help employers meet the requirements to ensure proper initial fitting and supervise the correct use of all hearing protectors.
In a 2014 study, nearly 30% of employees in an OSHA-compliant hearing conservation program were not receiving adequate attenuation for their workplace noise exposures. (Smith, et. al.). In light of the how widely hearing protection attenuation varies among workers, 3M strongly recommends fit-testing to verify the attenuation obtained by each employee.
Fit-testing systems such as the 3M™ E-A-Rfit™ Dual-Ear™ Validation System are referred to as Field Attenuation Estimation Systems (FAES). The measurement obtained during FAES testing is the Personal Attenuation Rating (PAR). The PAR provides a moment-in-time snapshot of how well the hearing protector is reducing sound for that individual worker. Although hearing protector fit may vary from day-to-day, fit testing helps to verify that each worker is capable to fitting his/her hearing protectors correctly and obtaining adequate attenuation and that the hearing protector is appropriate for the size and shape of the ear canal or head. Find out more about 3M™ E-A-Rfit™ by clicking here.
Some of the key benefits of HPD fit-testing are:
IMPORTANT NOTE: This information is based on selected current national requirements. Other country or local requirements may be different. Always consult User Instructions and follow local laws and regulations. This website contains an overview of general information and should not be relied upon to make specific decisions. Reading this information does not certify proficiency in safety and health. Information is current as of the date of publication, and requirements can change in the future. This information should not be relied upon in isolation, as the content is often accompanied by additional and/or clarifying information. All applicable laws and regulations must be followed.