Deafness Latest Situation About 16-million people in the United States have lost some of their hearing. About 2-million

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问题                                  Deafness
    Latest Situation
    About 16-million people in the United States have lost some of their hearing. About 2-million others are extremely or completely deaf. They can not hear speech or most other sounds in their everyday environment, even with a hearing aid to make sounds louder.
    Categories of Hearing Loss
    There are several kinds of hearing loss. One is conductive hearing loss. It results from disease or injury to the outer or middle part of the ear. The damage prevents sound waves from reaching the inner ear. Usually, this form of hearing loss is not extreme. And a hearing aid or medical treatment often can restore hearing.
    A second kind of hearing loss involves the nerves. It is caused by damage to the inner ear. A loud noise or disease may destroy some of the tiny nerve cells that carry sound. People suffering this kind of damage may lose the ability to hear some sounds, high or low. For example, they may be able to hear the low noise of a truck, but not speech. Hearing aids usually can not help people with this kind of deafness.
    The third kind of deafness is called a central hearing loss. It is caused by damage to the hearing nerves leading to the brain or in the brain itself.
    Causes of Deafness
    Deafness is the most common bodily disability in America. Often nothing can be done to stop it. But many cases can be prevented.
    One simple thing is responsible for most hearing loss. That one thing is noise—telephone bells, loud music, vehicles, or machines. In industrial countries, especially, these things make the environment very noisy. Studies have shown that old men in quiet African villages have much better hearing than young people in America.
    Other causes of deafness include accidents, brain tumors, some drugs, and car infections or other illnesses. Babies born too early may have damaged hearing. And about half of all deafness is at least partly caused by damaged genes, passed from parent to child. Rarely do the parents know they possess a gene for deafness. They can hear very well. Yet their child is born deaf. More than 90 percent of deaf children are born to hearing parents.
    Problems Caused by Deafness
    Not everyone who is deaf is disabled in the same way. This is because the disability generally depends on two things: the age at which hearing is lost, and the amount of deafness. Those who lose their hearing early in life—before they have learned to speak—usually have greater problems than those who lose it later in life.
    One problem is communication. The deaf are cut-off from the language used by hearing people around them. But deaf people around the world have created hundreds of languages that are spoken with the hands. Most deaf people in North America use American Sign Language to communicate with each other. In the United States, it is the fourth most commonly used language following English, Spanish and Italian.
    For many deaf Americans, English is a second language. They learned American Sign Language first. People who learn sign language as their first language think in it. They even dream in it. As hearing people may talk in their sleep, deaf people may make signs in their sleep.
    For many years, American Sign Language was banned in schools for the deaf in the United States. Educators feared that sign language would keep deaf people from communicating with hearing people. Today, schools for the deaf have begun to accept American Sign Language. Few classes are taught completely in American Sign Language. But some teachers mix American Sign Language with a sign language form of English called "Signed English". The idea is to permit deaf people to use any methods of communication they find useful.
    Devices to Help the Deaf
    Educators are not the only ones trying to help the deaf today. Scientists and inventors are helping, too. They are continuing to develop devices to make life easier for the deaf. One such device is the hearing aid which is worn in or near the ear. It makes sounds louder. Experts say common hearing aids have improved greatly in the past few years. The new devices are lighter and smaller. They do not produce as many unpleasant noises as earlier kinds. Some are so finely designed that they make louder only those sounds which a person can not hear well.
    Scientists also are working on devices that could give the deaf a sense that is much closer to real hearing. Most of these devices make it possible for the deaf to "feel" sounds they can not hear.
    One of the newest of these devices is called a cochlear(耳蜗)implant. Part of it is placed deep in the ear in a medical operation. The cochlear implant does some of the work of damaged ear nerves. Its wires lead directly to the inner ear. This is where sound waves are turned into electrical signals and sent to the brain. People with a cochlear implant can learn to recognize some sounds in their environment. Many can recognize automobiles and animals. About one-third can recognize speech. Lip-reading also becomes easier with a cochlear implant. However, both the device and the operation are very costly. The latest version of the device costs 25,000 dollars. And the earlier versions produce unpleasant sounds. Some deaf persons who have tried cochlear implants have rejected them. They have decided that they like silence better.
    Another new device to help the deaf is called a tactual vocoder(voice coder). It is the size of a small radio and is worn outside the body. The tactual vocoder uses the skin as a substitute for ears. It turns sounds into electrical signals felt on the chest. Different groups of these signs mean different sounds. Instead of heating language, a deaf person feels it.
    Another important aid for the deaf are printed messages that show what is being said on television programs. The messages appear on a small part of the television screen. They make it possible for deaf people to watch news programs and to follow the action on some other popular programs. People who wish to see the printed messages must buy a special device to connect to the television.
Hearing loss is the most widespread disease in the United States.

选项 A、Y
B、N
C、NG

答案C

解析 虽然从文章第一句可知,在美国有许多人(16-million people)失聪,但文章并没有说耳疾在美国是分布最广的疾病。因此,题干的内容在原文中找不到正面或反面的依据。
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