Noise Induced Hearing Loss and Its Prevention (cont.)
James K. Bredenkamp, MD, FACS
Dr. Bredenkamp recieved his medical degree from the University of California, San Francisco School of Medicine. He then went on to serve a six year residency at the University of California, Los Angeles School of Medicine in the department of Surgery.
Melissa Conrad Stöppler, MD
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
In this Article
- What is the importance of noise-induced hearing loss?
- What are acoustic trauma and noise-induced hearing loss?
- How can a person tell if a noisy situation is dangerous to their hearing?
- How loud can a sound get before it affects hearing?
- Do the duration and closeness of exposure to loud noise relate to hearing damage?
- What factors increase a person's susceptibility to noise-induced hearing loss?
- How else can noise affect a person?
- What are the regulations regarding on-the-job exposure to noise?
- How effective are hearing protection devices?
- What are the common problems with hearing protectors?
- Do hearing protectors prevent a person from communicating with others?
- How is hearing loss identified?
- What can be done to treat hearing loss?
- Find a local Ear, Nose, & Throat Doctor in your town
What are the common problems with hearing protectors?
Studies have shown that one-half of the workers wearing hearing protectors receive only one-half or less of the noise reduction potential of their protectors. This diminished protection occurs because these devices either are not worn continuously while exposed to noise or they do not fit properly.
As previously mentioned, a hearing protector can give an average of 30 dB noise reduction if worn continuously during an 8-hour workday. If taken off for just one hour while exposed to noise, however, such a protector would provide only an average of 9 dB of protection during the 8 hours. This substantial reduction in protection occurs because with the logarithmic scale used to measure decibels, a 10-times increase in noise energy occurs for each 10 dB increase in sound. Thus, during the hour with unprotected ears, the worker is exposed to 1,000 times more sound energy than if earplugs or muffs had been worn. (For the 30 dB, 10 x 10 x 10 = 1000 times more noise.)
In addition, noise exposure is cumulative. So, the noise at home or at play must be counted in the total exposure during any one day. A maximum allowable on-the-job exposure followed by further exposure at home to a noisy lawnmower or loud music will definitely exceed the safe daily limit.
Even if earplugs and/or earmuffs are worn continuously while exposed to noise, they do little good if there is an incomplete air seal between the hearing protector and the skin. As mentioned above, when using ordinary hearing protectors, it is common to hear one's voice as louder and deeper. This plugged ear effect can actually be taken as a useful sign that the hearing protectors are properly positioned.
Do hearing protectors prevent a person from communicating with others?
The answer is no, at least for people with normal hearing. In fact, just as sunglasses help vision in very bright light, hearing protectors enhance speech understanding in very noisy places. Even in a quiet setting, a normal-hearing person wearing hearing protectors should be able to understand a regular conversation.
Hearing protectors do slightly reduce the ability of those with damaged hearing or poor comprehension of language to understand normal conversation. Nevertheless, it is essential that persons with impaired hearing wear earplugs or earmuffs to prevent further inner ear damage from noise.
It has been argued that hearing protectors might reduce a worker's ability to hear the noises that signify an improperly functioning machine. Most workers, however, readily adjust to the quieter sounds and can still detect such problems.
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