Although hearing loss can occur at any age, hearing difficulties at birth or that develop during infancy and the toddler years can have serious consequences. This is because normal hearing is needed to understand spoken language and then, later, to produce clear speech. Consequently, if your child experiences hearing loss during infancy and early childhood, it demands immediate attention. Even a temporary but severe hearing loss during this time can make it very difficult for the child to learn proper oral speech.
Most children experience mild hearing loss when fluid accumulates in the middle ear from allergies or colds. This hearing loss is usually temporary and normal hearing commonly resumes once the cold and allergies subside and the Eustachian tube (which connects the middle ear to the throat) drains the remaining fluid into the back of the throat. In many children (approx. 1 in 10), fluid stays in the middle ear following an ear infection because of various problems with the Eustachian tube. These children don’t hear as well as they should, and sometimes have delays in talking.
Much less common is the permanent kind of hearing loss that fully endangers normal speech and language development. Permanent hearing loss varies from mild or partial, to complete or total.
There are two main kinds of hearing loss:
Conductive Hearing Loss
When a child has a conductive hearing loss, there may be an abnormality in the structure of the outer ear canal or middle ear, or there may be fluid in the middle ear that interferes with the transfer of sound.
Sensorineural Hearing Loss (also called nerve deafness)
This type of hearing impairment is caused by an abnormality of the inner ear or the nerves that carry sound messages from the inner ear to the brain. The loss can be present at birth or occur shortly thereafter. If there is a family history of deafness, the cause is likely to be inherited (genetic). If the mother had rubella (German measles), cytomegalovirus (CMV), or another infectious illness that affects hearing during pregnancy, the fetus could have been infected and may lose hearing as a result. The problem also may be due to a malformation of the inner ear. Most often the cause of severe sensorineural hearing loss is inherited.
Still, in most cases, no other family member on either side will have hearing loss because each parent is only a carrier for a hearing loss gene. This is called an “autosomal recessive pattern,” rather than “dominant” where it would be expected that other family members on one side would have hearing loss. Future brothers and sisters of the child have an increased risk of being hearing impaired, and the family should seek genetic counseling if the hearing loss is determined to be inherited.
Hearing loss must be diagnosed as soon as possible, so that your child isn’t delayed in learning language—a process that begins the day she is born. The American Academy of Pediatrics recommends that before a newborn infant goes home from the hospital, she needs to undergo a hearing screening. Thirty-eight states, in fact, now have Early Hearing Detection Intervention (EHDI) programs, which mandate that all newborns be screened for hearing loss before they are discharged from the hospital. At any time during your child’s life, if you and/or your pediatrician suspect that she has a hearing loss, insist that a formal hearing evaluation be performed promptly. Although some family doctors, pediatricians, and well- baby clinics can test for fluid in the middle ear—a common cause of hearing loss—they cannot measure hearing precisely. Your child should go to an audiologist, who can perform this service. She may also be seen by an ear, nose, and throat doctor (ENT; an otolaryngologist).
If your child is under age two, or is uncooperative during her hearing examination, she may be given one of two available screening tests, which are the same tests used for newborn screening. They are painless, take just five to ten minutes, and can be performed while your child is sleeping or lying still. They are:
- The auditory brainstem response test, which measures how the brain responds to sound. Clicks or tones are played into the baby’s ears through soft earphones, and electrodes placed on the baby’s head measure the brain’s response. This allows the doctor to test your child’s hearing without having to rely on her cooperation.
- The otoacoustic emissions test, which measures sound waves produced in the inner ear. A tiny probe is placed just inside the baby’s ear canal, which then measures the response when clicks or tones are played into the baby’s ear. These tests may not be available in your immediate area, but the consequences of undiagnosed hearing loss are so serious that your doctor may advise you to travel to where one of them can be done. Certainly, if these tests indicate that your baby may have a hearing problem, your doctor should recommend a more thorough hearing evaluation as soon as possible to confirm whether your child’s hearing is impaired.
Treating a hearing loss will depend on its cause. If it is a mild conductive hearing loss due to fluid in the middle ear, the doctor may simply recommend that your child be retested in a few weeks to see whether the fluid has cleared by itself. Medication such as antihistamines, decongestants, or antibiotics are ineffective in clearing up middle ear fluid.
If there is no improvement in hearing over a three-month period, and there is still fluid behind the eardrum, the doctor may recommend referral to an ENT specialist. If the fluid persists and there is sufficient (even though temporary) conductive hearing impairment from the fluid, the specialist may recommend draining the fluid through ventilating tubes. These are surgically inserted through the eardrum. This is a minor operation and takes only a few minutes, but your child must receive a general anesthetic for it to be done properly, so he usually will spend part of the day in a hospital or an outpatient surgery center.
Even with the tubes in place, future infections can occur, but the tubes help reduce the amount of fluid and decrease your child’s risk of repeated infection. They will also improve his hearing.
If a conductive hearing loss is due to a malformation of the outer or middle ear, a hearing aid may restore hearing to normal or near-normal levels. However, a hearing aid will work only when it’s being worn. You must make sure it is on and functioning at all times, particularly in a very young child. Reconstructive surgery may be considered when the child is older.
Hearing aids will not restore hearing completely to those with significant sensorineural hearing loss, but they will help your child develop spoken or oral language if the hearing impairment is mild or moderate. Should your child have severe or profound hearing impairment in both ears and receives no benefit from hearing aids, she will become a candidate for a cochlear implant. Cochlear implants have been approved by the government for children over one year old since 1990. There is now enough experience with them to say that cochlear implants work well for the vast majority of children who have normal brain function. If your family is considering an implant for your child, results for developing useful speech are better with early (less than three years old) rather than late (over seven years old) implantation. At best, these “cochlear implants” help a person to become aware of sounds. They do not restore hearing nearly well enough for the child to learn spoken language without additional help, including hearing aids to amplify sounds, as well as special education and parent counseling. Recently there have been a number of cases of serious infections complicating cochlear implants even months after surgery. Many are being removed. Because of this, if your child has a cochlear implant, contact your ENT surgeon or pediatrician immediately for the best next step.
Parents of children with sensorineural hearing loss usually are most concerned about whether their child will learn to talk. The answer is that all children with a hearing impairment can be taught to speak, but not all will learn to speak clearly. Some children learn to lip-read well, while others never fully master the skill. But speech is only one form of language. Most children learn a combination of spoken and sign language. Written language also is very important because it is the key to educational and vocational success. Learning excellent oral language is highly desirable, but not all people who are born deaf can master this. Sign language is the primary way deaf people communicate with one another and the way many express themselves best.
If your child is learning sign language, you and your immediate family also must learn it. This way you will be able to teach her, discipline her, praise her, comfort her, and laugh with her. You should encourage friends and relatives to learn signing, too. Although some advocates in the deaf community prefer separate schools for deaf children, there is no reason for children with severe hearing impairment to be separated from other people because of their hearing loss. With proper treatment, education, and support, these children will grow to be full participants in the world around them.
Hearing Loss: What to Look For and When to Call Your Pediatrician
Here are the signs and symptoms that should make you suspect that your child has a hearing loss and alert you to call your pediatrician.
- Your child doesn’t startle at loud noises by one month or turn to the source of a sound by three to four months of age.
- He doesn’t notice you until he sees you.
- He concentrates on gargling and other vibrating noises that he can feel, rather than experimenting with a wide variety of vowel sounds and consonants.
- His speech is delayed or hard to understand, or he doesn’t say single words such as “dada” or “mama” by twelve to fifteen months of age.
- He doesn’t always respond when called. (This is usually mistaken for inattention or resistance, but could be the result of a partial hearing loss.)
- He seems to hear some sounds but not others. (Some hearing loss affects only high-pitched sounds; some children have hearing loss in only one ear.)
- He seems not only to hear poorly but also has trouble holding his head steady, or is slow to sit or walk unsupported. (In some children with sensorineural hearing loss, the part of the inner ear that provides information about balance and movement of the head is also damaged.)
Source: Caring for Your Baby and Young Child: Birth to Age 5 (Copyright © 2009 American Academy of Pediatrics)