The Noise Center

Response: Ears do not get used to noise – they “get deaf” (and unfortunately a deafened ear may often seem to get used to the noise). Repeated exposure to noise does not toughen ears nor does having an existing noise induced hearing loss prevent you from losing the hearing you have left. Although individual susceptibility to hearing loss from noise exposure varies widely, there are currently no standardized tests that can detect the more noise sensitive members of the population.

Response: The existence of a noise induced hearing loss does not protect one from further loss of hearing due to noise exposure. Initially hearing is damaged in the higher frequencies and as the unprotected exposures continue, this damage spreads to the lower frequencies, eventually affecting those essential to the understanding of speech (500 Hz to approximately 3000 Hz).

Although HPDs cannot restore a noise induced hearing loss, which by its nature is permanent and irreversible, they should prevent additional losses from being incurred.

Response: HPDs are often uncomfortable initially, but hearing loss due to noise exposure is “uncomfortable” permanently. Like a new pair of shoes or glasses, hearing protectors do require a reasonable period of adjustment. Since not all hearing protectors adapt equally well to all head shapes and earcanals, it is important to give the employee the final choice in what he or she will wear. If after a couple of weeks of daily use the employee is still experiencing difficulties or discomfort, the protector should be resized and/or refitted, or another hearing protector should be issued.

Response: When the ear is bombarded with high level sound, it overloads and distorts, reducing its ability to accurately discriminate different sounds. Wearing HPDs reduces the overall sound levels so that the ear can operate more efficiently. The effect is similar to the improved vision that sunglasses provide in very bright, high-glare conditions.

​

For those with normal hearing, HPDs will usually provide improved communications when sound levels are greater than approximately 85 dBA. For moderate to severely hearing impaired individuals, the situation is more complicated; for them, hearing protectors may not provide a communications benefit and actually be a liability. But, if these individuals do not protect their hearing, they may suffer additional impairment, and then they will have even greater difficulty communicating regardless of noise level.

Response: No. The misconception that earmuffs are better than earplugs at reducing noise is partly due to the “bigger is better” school of thought. Actually, whether or not an earmuff or an earplug is better is dependent upon the device and user in question.

Response: Based on our experience during the past decade, and information gleaned from consultation with experts in the field of otology and audiology, as well as data from an ongoing survey of U.S. industries, it appears that the likelihood of earplugs causing outer ear infections (otitis externa) is minimal. Although it would seem that placing a dirty or gritty foreign object in the earcanal could easily lead to irritation or infection, the data from existing HCPs [Hearing Conservation Programs} seem to indicate that the external ear is fairly resistant to such abuse. Nevertheless, cleanliness should be stressed and certain individuals, such as diabetics and those who are prone to infection, should be more carefully monitored.

Response: Headaches may be caused by an HPD (primarily circumaural devices) that fits too tightly, or is in some other way uncomfortable. The HPD should be resized, refitted or another device issued.

​

There are no known medical or physiological reasons why HPDs should be suspected of causing any of the remaining maladies listed above. However, when an employee voices such complaints, this indicates dissatisfaction with the HPD he is wearing, a misunderstanding of the need for its use, or a real health problem that has been mistakenly attributed to the use of the HPD. The best response will be a patient and accurate assessment of the situation and determination of the actual cause of the disorder.

Response: The foam earphones offer almost no protection. Even the circumaural device provides no more than approximately 20 dB of attenuation at high frequencies, and actually significantly amplifies sounds at some frequencies. This protection is inferior to that of a well designed, properly fitted HPD. Furthermore, these devices alone can generate equivalent noise exposures up to approximately 100 dBA.

Since these devices offer so little attenuation, a greater concern is that employees might turn up the music to mask (i.e., “drown out”) the factory noise. Products are available which have been specifically designed to offer adequate protection and at the same time play music or transmit voice communications. Although generally expensive, such devices are suitable for use, especially when they have built-in signal limiting circuitry so that they are not capable of presenting hazardous sounds to the ear.

Response: Although eyeglasses can in most cases correct a vision problem to a nearly normal condition, it is a misconception that hearing aids can do likewise for a noise induced hearing loss. Correctable vision problems generally result from ocular distortions and not the loss of the optic nerve cells, whereas noise damage is due to destruction of the nerve (hair) cells in the cochlea that enable us to hear. Hearing aids can restore the ability to detect and discriminate sounds to a certain extent, but when insufficient hair cells are present to receive the amplified sounds that the aid provides, the results are not fully satisfactory…and if wearing an HPD 8 hours/day is objectionable, will it be any more acceptable to wear a hearing aid (which feeds sound into the ear through an earplug like device) for all of one’s waking hours?