THURSDAY, DAY 4
THE MIND
Some people are born deaf. Others lose their hearing through injury, infection, or long-term exposure to loud noise. For others, deafness develops slowly with age. Whatever the reason, a diagnosis of hearing loss or deafness may require learning to communicate in a whole new way.
Hearing occurs when sound waves enter the outer ear and are converted into vibrations by the eardrum. These vibrations are amplified by three tiny bones (the stirrup, hammer, and anvil in Latin) in the middle ear, which respond to the eardrum and transmit the impulses to the inner ear. In the inner ear, nerve centers process those vibrations into electrical impulses and send them to the brain, where they are recognized as sounds.
Most hearing loss occurs when the inner ear or auditory nerves are damaged. In particular, loud music or noises, meningitis, or high fever may damage the cochlea, a structure in the inner ear. Certain antibiotics, chemotherapy drugs, and very high doses of anti-inflammatory drugs such as aspirin can also damage the inner ear, leading to hearing loss or ringing in the ear (called tinnitus). Temporary loss of hearing can also happen when sound waves cannot reach your inner ear because of fluid buildup, excessive earwax, or a punctured eardrum.
Diminished hearing can often be improved with hearing aids that amplify sound waves. A recently developed surgical procedure called a cochlear implant may restore hearing in some people with severe deafness by replacing damaged parts of the inner ear.
For people who are born deaf or lose their hearing completely, however, learning sign language often provides the best way to communicate. American Sign Language, developed in the 19th century, is understood by millions of people in the United States and in many other countries that have adopted the language.