Sensorineural loss of early age children : I hear but I can’t understand problem
Sensorineural loss of early age children : I hear, but I can’t understand problem
Sara has this type of hearing impairment, and for years she confused everybody. Her parents thought that as an infant she had reacted normally to the sounds around her. She had vocalized well and started to speak at the age of one. But when Sara reached one and-a-half her parents noticed that she didn’t always respond to being called. A doctor removed her tonsils and adenoids, but she didn’t improve. Finally her parents tried a hearing aid; Sara refused to wear it.
At this point the explanation seemed to be that Sara had an emotional problem. A year in a nursery class for the emotionally disturbed had no effect. The next year, when Sara was five, she entered a normal nursery school. There she seemed to respond fairly well, although she could not always follow directions.
She liked to recite before the class, but nobody could really understand what she said. She enjoyed playing with other children, but she communicated with them through pantomime. At five-and-a-half Sara still did not speak in sentences and her speech was far from clear. Her parents brought her to a speech and hearing clinic for testing.
They felt confused. “Why is it that Sara doesn’t hear the telephone ring, but still can understand everything her grandmother says to her over the phone?” they asked the doctors.
“Why does she always use her right ear when she listens to the radio?
Does she have an emotional problem? Is that why she’s so stubborn and refuses to talk better?”
After a very thorough work-up by a team of doctors and speech and hearing clinicians the answer was clear. Sara has a hearing loss, which is why she cannot learn to speak clearly. For her the problem is a particular kind of hearing impairment called a sensory-neural loss. This means that the damage is not in the outer or middle ear, but in the inner ear,
where different sound frequencies activate different nerve eels in the cochlea. If some of these nerve cells or their nerve pathways to the brain don’t function properly, then the ear will have difficulty perceiving sounds in certain frequency ranges.
This is what makes the behavior of a child like Sara so confusing. Sara could not hear consonant sounds very well. Most consonant sounds occur in the high frequency ranges of 1200 cps or above. If the nerve cells in the basal turn of the spiral-shaped cochlea which respond to these frequencies don’t function, then the child will hear all the vowel sounds, but will not be able to tell the difference between words with different consonant sounds. Sara cannot tell you the difference between words like “bit”, “kit”, and “sit”. She seems to hear through a filter, which screens out all the high frequency sounds.
Other children hear sounds in the high frequency range, but miss the low frequency ones. And some have a reduced sensitivity to all sound because damage has run throughout the cochlea.
Most children with a sensory-neural loss hear, but they hear incompletely. They hear, but they cannot understand you.
What can cause a sensorineural loss?
Sometimes an error occurs during the development of the inner ear and its nerve pathways and the child is born with a defective hearing mechanism. Sometimes certain conditions damage the sound-sensing nerve cells while the child is still in the womb, Incompatible factors between the parents’ and the child’s blood is one such
condition, and can injure the auditory nerve which carries signals from the nerve cells of the inner ear to the brain.
Viral diseases like flu or mumps during the mother’s pregnancy can also pass from her to her unborn child, destroying the cells in the cochlea. German measles, also called rubella, can do this. An epidemic of rubella swept the United States during 1964, damaging thousands of children.
One study in Baltimore, Maryland, part of a research project sponsored by the National Institute of Neurological Diseases and Stroke, found more than 350 children in that city injured by German measles which had infected their mothers during pregnancy. Many of these children suffered multiple damages, such as blindness, mental retardation and heart defects. The Baltimore unit’s study showed that more than 50 percent of the children infected by German measles also had communication problems.
Many of these children are being missed because they appear normal until their hearing is tested. Thus any mother exposed to German measles during her pregnancy should be especially alert to signs of deafness in her child.
Scarlet fever and meningitis, an inflammation of the tissues lining the brain, can also cause nerve damage in childhood.
There is no way to restore a nerve cell, once it is damaged. Thus hearing aids do not always help.
Sometimes, however, amplifying a sound will make the stirrup bone transmit a stronger vibration to the inner ear and thus cause a greater number of nerve cells to react to a sound. In other cases this will not work. Training in lip-reading can help a child learn to use his eyes to help him understand better and speech training can assist him in making sounds he can’t hear
well enough to imitate on his own. If such help comes early enough, the child with a sensory-neural loss may develop enough language and speech to be able to get along in a regular school class. Often such children need the individual attention and the experienced teaching available in special classes for the deaf.
Not all hearing impairments fall neatly into these two categories, of course. Some children contend with both conductive and sensory-neural damage. In some cases the damage is slight and in others very severe.
Then there are the children who have only one bad ear. They will find it difficult to locate the source of sound since it can only reach them through one side of the head.
One mother became aware that her son had this problem at a birthday party where the children were playing a game called “telephone.” The leader had to think of a message and whisper it to the next child and so it went around the circle and back to the first child again. When it came Tommy’s turn his mother was startled to hear him say:
“You’ll have to whisper in my right ear ’cause it’s my whispering ear and the other one’s no good.”
Tommy needs to have preferential seating in the classroom so that his good ear is always toward the teacher and the other students.
Sensorineural loss of early age children : I hear but I can't understand problem article Source Learning to talk by National Inst. of Health Bethesda ,Md, document