Occupational hearing loss

Alternative names:

hearing loss - occupational

Definition:

Hearing loss caused by damage to the inner ear from noise or vibration as a result of certain occupations or forms of entertainment.

Causes, incidence, and risk factors:

Occupational hearing loss is a form of acoustic trauma caused by exposure to vibration or sound. This may commonly occur with certain occupations or entertainments.

Sound is heard as the ear converts vibration from sound waves into impulses in the nerves of the ear. Sounds above 90 decibels (dB, a measurement of the loudness or strength of vibration of a sound), particularly if the sound is prolonged, may cause such intense vibration that the inner ear is damaged. Ninety decibels is about the loudness of a large truck about 5 yards away. A jackhammer emits sounds of about 120 dB from 3 feet away, and a jet engine emits sound of about 130 dB from 100 feet away. Motorcycles, snowmobiles, and similar engines range around 85 to 90 dB, and a rock concert may approach 100 dB. A general rule of thumb is that if you need to shout to be heard, the sound is in the range that can damage hearing.

Some jobs, such as construction, airline ground maintenance, farming, and entertainment involving loud noise from music or machinery, carry high risk for hearing loss. In the U.S., the maximum job noise exposure is regulated by law. Both the length of exposure and the extent (decibel level) of exposure are considered. If exposure is at or greater than the maximum exposure, protective measures must be taken.