Responding is Theresa Y. Schulz, hearing conservation manager, Howard Leight/Honeywell Safety Products, San Diego.
It is important to find the right amount of protection from a hearing protector.
Selection of hearing protection can be made for the wrong reasons. An unfortunate tendency is to look for the highest noise reduction rating. But in many instances, high NRRs can be too much of a good thing. This is especially critical for workers with hearing loss.
Workers with hearing loss may already have difficulty understanding speech in noisy environments, and hearing protectors decrease all sounds. When workers need to hear in a hazardous noise environment, they often remove their hearing protection to make the desired signal louder and more understandable. When we provide hearing protection that overprotects from environmental noise, we unintentionally create the need to remove hearing protection.
The goal of hearing protection should be to decrease the level of sound input to the ear to about 70-80 dB. Fit-testing earplugs can help determine the proper hearing protector for each worker’s noise environment. Fit-testing shows how much protection a worker achieves with a given fit. The next step is to look at the noise exposure and determine if that individually measured amount of protection results in a “Protected Exposure Level” in the desired range. If the PrEL is too high, the worker is at risk for hearing loss. If the PrEL is too low, the worker could be at risk for overprotection.
If noise exposure varies from high (more than 95 dB) to fairly low (low 80s to 95 dB), workers might be better served by using different hearing protectors, each appropriate for the noise exposure at that time.
Flat attenuation hearing protectors
Most hearing protectors provide more protection in the high frequencies than low frequencies. Protectors designed to provide level protection across all frequencies (flat attenuation) can help hearing-impaired workers maintain their connection to the environment, including speech communication and warning signals. These “flat attenuation” protectors often provide a little less protection, which may be more appropriate.
Electronic sound amplification
Electronic sound management protectors use external microphones that amplify ambient sound up to a certain level, but block noises more than about 82 dB. They can be especially useful for workers with hearing impairments.
An OSHA Safety and Health Information Bulletin published in 2005 provides guidance for accommodating the safety and health needs of hearing-impaired and deaf workers specific to emergency evacuation and hazard communication. Additional technology has been developed since the 2005 bulletin that provides options for accommodating workers with hearing impairment. These include communication systems that protect from hazardous noise while amplifying radio signals and/or face-to-face speech.
Editor's note: This article represents the independent views of the author and should not be construed as a National Safety Council endorsement.