When should babies have hearing tests?
Then how do you know if your baby should have a hearing test? All high-risk babies should. Babies from families in which there is a history of deafness should be tested. a baby who had a low birth weight or one who became jaundiced soon after birth would be considered high risk; so would a baby whose delivery was difficult and who might have suffered from lack of oxygen. And, of course, if the parent thinks the child has a hearing loss, the test should be performed immediately, because today there are sophisticated computerized methods.
A one-day-old infant can be tested for hearing. Audiologists do behavioral testing. In addition, an evoked response audiogram can be done on a sleeping baby. This actually is a very sophisticated computerized test. It is called the brain stem evoked response (BSER) audiogram. Electrodes are put on the head like an EEG (electroencephalogram) and are connected to a computer with sound stimulus. Then the brain's responses to sound can be picked up. Since they are obviously not very big impulses, they can only be measured by computer. It works because you get multiple stimuli and they keep adding up until you get a nice, accurate response. A trained audiologist, with at least a master's degree, should perform the BSER test; the equipment is now available in most cities.
We want our readers to know about the availability of this test for infants because the otologists (ear specialists) with whom we have spoken all confirm that they see cases of toddlers or even older children, who could have been helped with hearing aids, learning less because they haven't been hearing. The earlier the detection, the more you are able to do to help them develop more normal speech.
Babies with a neural loss can benefit from a hearing aid very early. One otologist told me of having put a hearing aid on an infant at age six months. Very few babies have total deafness. They may not hear much, but they have some nerve fibers that can be stimulated. They can learn to use those fibers more appropriately, and they can learn speech better.
Some of the causes of deafness in infants include congenital defects, meningitis, intrauterine infections, lack of oxygen during birth, too much oxygen after birth, hyperbilirubinemia (jaundice is present) and some of the viral diseases such as cytomegalic inclusion disease. A baby whose mother took quinine during pregnancy may have hearing loss. (Quinine is transmitted across the uterine wall, and malaria was formerly the most common reason that a woman might be taking quinine-containing drugs.)
Even for a six-month-old baby, the hearing aid works, and most specialists agree that early intervention is especially important for infants.
The most common tip-off that a child's hearing may be poor is the volume on the TV set. If it keeps going louder and louder, a parent should guess that his child is hearing less and less. Another clue--asking the child to do something he has always liked to do, and he doesn't follow through.
Typically, a child with a conductive hearing loss will speak more softly than is normal. This is the deafness we find in the middle-ear problems. It is completely different from nerve loss, as persons with the latter tend to speak loudly. (Once he is in school, chances are that a child with a hearing test. Preschoolers, however, can easily be missed.)
We asked Dr. Laverne Tubergen, an otologist at Indiana University, to explain the hearing loss in children when their middle ear fills with fluid. This is what he told us:
"The problem of middle-ear disease starts when the Eustachian tube, which connects the middle ear and the back of the nose, becomes plugged. Normally this is closed, but when we yawn or swallow, enough air enters the middle ear so that we have a nice air-containing space. Now in disease conditions such as a cold, this tube becomes plugged up, and in children it plugs up quickly because it is very narrow. When it swells, no air can get into the middle ear. This creates a vacuum that then causes fluid to pour out from all the little blood vessels. Now we have a 'drum' full of fluid, which can no longer transmit sound as readily. That is why children with middle-ear infections have decreased hearing. It's their No. 1 symptom. At first, fluid which accumulates there is sterile, but after sitting there it becomes infected--then, in addition to the hearing loss, the child has pain and fever.
"It is the fluid that impedes the motion of the eardrum and thus gives us our hearing loss," Dr. Tubergen explained. "so that when a child's ear doesn't dry up and there is hearing loss from the fluid which remains in the middle ear, the otologist will think of making an artificial Eustachian tube to let the fluid out and air come into the middle ear."
When the eardrum can't vibrate, doctors replace the Eustachian-tube function by putting a little hole in the eardrum that allows the fluid to drain. But that's not the real purpose, which is to allow air to get in there so the fluid doesn't re-form.
Once the hole is in the eardrum, the fluid is removed by suctioning. It is very important that this be done by someone with a microscope and micro instruments--an ear, nose and throat doctor trained in this procedure, for example. If the doctor just makes a hole in the eardrum, it will heal up in about 24 hours, and he must start the whole process over again. To prevent this, he puts a small polyethylene or metal tube in the eardrum. This is done with an operating microscope. Since he's dealing with a very small structure in the ear drum and there are important structures within the middle ears, any permanent damage to these little bones of hearing is avoided by using this magnifying equipment. It's done in an operating room, or with a cooperative child it can be done under local anesthetic in the doctor's office. The tube will generally come out on its own; the average duration is six to eight months. It may come out sooner than that; occasionally it stays in longer.
What are the major indications that your child needs to have a tube inserted? Dr. Tubergen reports that the prime indication is persistent fluid in the middle ear, fluid that causes a hearing loss. If children with normal hearing have fluid in the middle ear, doctors can watch but do not have to go ahead with the surgery. If there is a hearing loss and persistent fluid, however, that's the time to put in the tubes.
"I think many of the ear infections can be handled by the family doctor or the pediatrician," says Dr. Tubergen. "There are a couple of occasions, however, when I think they specifically ought to be seen by an ear, nose and throat doctor or otologist and audiologist. One, if they have frequent ear infections, maybe one or two a year. If they are having these frequently over the winter, that would be a time that they ought to see a specialist. Or, in addition, if they have an ear infection that just doesn't go away. Usually an ear infection will clear up in seven to ten days or maybe two weeks. So, if they have a persistent infection for a month, those patients, too, should be seen by an ear, nose and throat doctor. The doctor then should do a thorough examination and, in addition, should measure the hearing with a hearing test. Most of the time this is done by an audiologist, who is a specialist in hearing testing."
We asked Dr. Tubergen about the common antibiotics being used for ear infections.
"Most of the time the ear infections will clear up on the penicillin or one of the synthetic penicillins, such as ampicillin. There are some newer drugs that we use in the very refractory cases, but this is not common."
The use of decongestants being controversial, we asked his views about this.
"Well, theoretically it makes a lot of sense to use decongestants," he responded. "Theoretically, decongestants reduce the swelling of the lining of the Eustachian tube and allow it to work. Practically, and in clinical studies, they have no good effect. This has been confirmed through studies by pediatricians as well as ear, nose and throat physicians. So my own personal experience is that I restrict use of decongestants to children that may have nasal problems rather than ear problems. It does not have any significant effect on ear infections or fluid in the ear."
As a precaution, Dr. Tubergen suggests that parents and children never use Q-tips to clean ears. In his experience attempts by individuals to clean ears using cotton swabs is the most common cause of traumatic eardrum perforation. Such punctures have been known to produce permanent damage to the little bones of hearing in the middle ear.
If your school doesn't have a hearing test program, you might want to correct this omission. most ENT specialists see several children each year who are referred because of failing the school hearing test, and they consider this a very important part of the school system.
"It's not a definitive test; in many cases the children coming in who have failed the school test actually have normal hearing; if a child passes the school hearing test, you can feel quite certain that the child hears normally," said Dr. Tubergen.
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|Publication:||Saturday Evening Post|
|Date:||Apr 1, 1984|
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