Catherine Martin, age 10, of Charlotte, N.C., for her question:
CAN A DEAF PERSON HEAR HIMSELF TALK?
One type of deafness is not due to a physical change in the ear but rather to some faulty mental processes. Patients may be able to hear sounds but they are not able to understand words. Sudden shocks may produce this condition.
Concussions from explosions can puncture eardrums which will usually heal in a few days. Some, however, continue to think of themselves as deaf after such an accident and must be treated with counseling. Deafness is a complete or partial inability to hear.
About seven out of 100 children in public schools today cannot hear as well as they should.
Ordinarily your ear will be able to hear sounds which have vibrations from between 20 and 20,000 cycles per second. Speech usually ranges between 200 and 3,000 vibrations per second in pitch. Sound is measured in decibels, which is a technical unit. A whisper is about 20 decibels in intensity, while ordinary conversation is between 50 and 60 decibels.
Hearing is considered to be good if all sounds between 64 and 8,192 vibrations at 20 decibels are heard. Deafness which handicaps a person begins when the tones in ordinary speech cannot be heard at a whisper.
Sometimes only part of a person's tone range is interfered with. Deafness can increase until it is almost impossible to hear any sound, but it has been found that most deaf persons can hear at least one sound.
If a person is totally deaf, he cannot hear a thing including his own voice.
Some people are born deaf, and some lose their hearing from disease or other causes. Most hearing problems are caused by diseases that do not necessarily start in the ear but reach it from some other part of the body. Common colds, tonsillitis, scarlet fever and measles are often causes of this type of deafness.
Deaf persons who do not speak are sometimes called deaf mutes. Most people of this type are not truly mute since they could learn to speak. Persons who are born deaf or lose their hearing early in life experience great difficulty in learning to talk because they cannot hear others speak. When such a person learns to talk, his own speech may be difficult to understand because he cannot hear to correct his own tone.
A person who knew how to speak before he became totally deaf retains the power of speech, although his voice may become harsh and unnatural.
Various things can help deaf people to understand speech of others. Some learn to read lips, and the partially deaf can benefit from powerful hearing aids.