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Subject: Deafness

What is deafness

    Deafness is caused when sound waves are no longer perceived by the ear. This can be caused by a number of things. Some people's ears are injured and sometimes, children are born with defective middle or inner ears; the eardrum might not vibrate correctly, or pressure in the cochlea might not be right. Others are deaf due to diseases like meningitis or rubella. Some diseases attack the nerves which carry the vibrations to the brain. The ear might be working, in this case, but the nerves are not and thus, the brain doesn't realize sound is happening. As people get older, they tend to lose their hearing. The main cause of hearing loss is the breaking down of the hammer, anvil, and stirrup. They don't vibrate together and the vibrations get "lost." Sometimes, this happens at the eardrum as well. If the vibrations don't make it through the middle ear, they can't be transmitted to the inner ear and then sent to the brain.

Related links
How do we hear?

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This document was last modified on Tuesday, September 30, 2008 at 11:51:30.