Noise Induced Hearing Loss and Its Prevention
Medical Author: James K. Bredenkamp, MD, FACS
Medical Editor: Leslie J. Schoenfield, MD, PhD
What is the importance of noise induced hearing loss?
The industrial and technological revolution may have propelled society to
higher levels of achievement. At the same time, however, this progress has also
made the world a noisier place in which to live. In fact, noise pollution is a
growing health hazard and is everywhere. Car alarms, leaf blowers, gunshots,
boom boxes, and traffic congestion fill our cities with decibels (the measure of
sound intensity). Even escaping to the country may not provide a quiet refuge.
Thus, farmers are at high risk for exposure to noise from their farm machinery.
What's more, potentially harmful noise is not necessarily unpleasant or
unwanted. For example, the music at a concert or the pounding of a jackhammer on
the street can be equally damaging to the inner ear. The reason for this is that
any sounds (acoustic energies) delivered with equal intensity, regardless of
their source, are equally dangerous. Eventually, continued or repeated exposures
to high intensity sound can cause acoustic trauma to the ear. This trauma can
result in hearing loss, ringing in the ears (tinnitus), and occasional
dizziness
(vertigo), and nonauditory effects, such as increases in heart rate and blood
pressure.
One-third of the 30 million Americans with hearing loss
have an impairment that is at least partially attributed to excessive noise
exposure. Noise remains the most common preventable cause of irreversible
sensorineural (involving the ear's sensory nerve) hearing loss.
What are acoustic trauma and noise induced hearing loss?
Acoustic trauma
occurs when any excessive sound energy strikes the inner ear. If it is brief,
the noise may cause a reversible, temporary auditory fatigue, technically known
as a temporary threshold shift. For example, after a loud rock concert, it is
common to experience hearing dullness and ringing for several hours. In this
situation, if symptoms persist beyond several days, oral steroids
(cortisone-type medications) may help the inner ear recover. If the noise is
loud enough and the duration of exposure long enough, however, it may cause a
permanent threshold shift. This condition is called noise induced hearing loss,
and has no cure and is irreversible.
Hearing loss produced by a sudden and very loud noise
(blast injury) is called acute acoustic trauma. If the sound is loud enough, it can cause the
eardrum to rupture or the person to
have a complete loss of hearing. Sometimes, particularly if the sudden loss is
total and combined with dizziness, immediate surgical exploration of the ear may
be necessary. In this circumstance, the ear surgeon may need to locate and patch
a hole (perilymphatic fistula) between the
inner ear fluid space and the middle ear space.
Next: How can a person tell if a noisy situation is dangerous to their hearing? »
- Ear Tubes - Learn about ear tubes (myringotomy), a procedure that allows ventilation in the middle ear. Pre-surgery, during surgery, post surgery, and follow-up information is included.
- Tinnitus - Learn about tinnitus, or ringing in the ears caused by exposure to loud noises, medication (aspirin), and some diseases like Meniere's disease.
- Newborn Infant Hearing Screening - Find out how and when newborn infant hearing screening is done, and learn what to do if hearing impairment or deafness is detected.
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