Hearing impairment refers to any degree of hearing loss, mild to severe, and can occur when there is a problem with a part of the ear, including the inner, middle, and outer ears, or the nerves needed for hearing.
Hearing impairment in newborns most commonly results from cytomegalovirus infection or genetic defects and in older children results from ear infections or earwax.
If children do not respond to sounds, have difficulty talking, or are slow starting to talk, the cause may be hearing impairment.
A handheld device or a test that measures the brain’s responses to sounds is used to test hearing in newborns, and various other techniques are used for older children.
Untreated hearing impairment can impede a child's verbal, social, and emotional development.
If possible, the cause is treated, but hearing aids may be needed.
If hearing aids are not effective, a cochlear implant can sometimes be helpful.
Hearing impairment is relatively common among children. About 1.9% of children have trouble hearing, and permanent hearing loss is found in more than 1 out of every 1,000 children screened for hearing loss, whether or not they have symptoms.
Hearing impairment is slightly more common among boys. Not recognizing and treating impairment can seriously impair a child’s ability to speak and understand language. The impairment can lead to failure in school, teasing by peers, social isolation, and emotional difficulties.
(See also Hearing Loss in adults.)
Causes
The most common causes of hearing impairment in newborns are
When a baby is infected with CMV in the uterus, it is called congenital CMV infection. Congenital CMV infection is the most common congenital viral infection in the United States. Infected newborns can be born with hearing loss and many other problems. Hearing loss can also develop later in children who were infected immediately before, during, or shortly after birth.
Genetic defects are also common causes. Some genetic defects cause hearing loss that is evident at birth. Other genetic defects cause hearing loss that develops over time.
The most common causes of hearing impairment in infants and older children are
In older children, other causes include head injury, loud noise (including loud music), use of certain drugs that can damage the ears (such as aminoglycoside antibiotics or thiazide diuretics), certain viral infections (such as mumps), tumors or injuries affecting the auditory nerve, injury by pencils or other foreign objects that become stuck deep in the ear, and, rarely, a malfunction of the body's immune system that causes the body to attack its own tissues (autoimmune disorder).
Risk Factors for Hearing Impairment in Children
|
Did You Know...
|
Symptoms
Parents may suspect hearing impairment if the child does not respond to sounds or if the child has difficulty talking or delayed speech.
Less severe hearing impairment can be more subtle and lead to behavior that is misinterpreted by parents and doctors, such as the following:
Children sometimes ignore people who are talking to them.
Children are able to talk and hear well at home but not in school because mild or moderate hearing impairment may cause problems only in the midst of the background noise of a classroom.
In general, if children are developing well in one setting but have noticeable social, behavioral, language, or learning difficulties in a different setting, they should be screened for hearing impairment.
Screening and Diagnosis
For newborns, routine hearing screening tests
For older children, a doctor's evaluation and tympanometry
Imaging tests
Because hearing plays such an important role in a child’s development, many doctors recommend that all newborns be tested for hearing impairment by the age of 3 months.
Most states require that newborns undergo routine screening tests to detect hearing impairment. Newborns are usually screened in two stages. First, newborns are tested for echoes produced by healthy ears in response to soft clicks made by a handheld device (evoked otoacoustic emissions testing). If this test raises questions about a newborn’s hearing, a second test is done to measure electrical signals from the brain in response to sounds (the auditory brain stem response test, or ABR). The ABR is painless and usually done while newborns are sleeping. It can be used in children of any age.
If results of the ABR are abnormal, the test is repeated in 1 month. If hearing loss is still detected, children may be fitted with hearing aids and may benefit from placement in an educational setting responsive to children with impaired hearing.
If doctors suspect the child has a genetic defect, genetic testing can be done.
In older children, several techniques are used to diagnose hearing impairment:
Asking a series of questions to detect delays in a child’s normal development or to assess a parent’s concern about language and speech development
Examining the ears for abnormalities
For children aged 6 months to 2 years, testing their response to various sounds
Testing the response of the eardrum to a range of sound frequencies (tympanometry), which may indicate whether there is fluid in the middle ear
After age 2 years, asking children to follow simple commands, which usually indicates whether they hear and understand speech, or testing their responses to sounds using earphones
Imaging tests are often done to identify the cause of hearing loss and guide prognosis. Magnetic resonance imaging (MRI) is done for most children. If doctors suspect bone abnormalities, computed tomography (CT) is done.
Prognosis
Not recognizing and treating hearing impairment can seriously impair speech and understanding of language. The impairment can lead to failure in school, teasing by peers, and social and emotional problems.
Treatment
Treating the cause when possible
Hearing aids or cochlear implants
Sign language
Treating reversible causes of hearing loss and ear defects can restore hearing. For example, ear infections can be treated with antibiotics or surgery, earwax can be manually removed or dissolved with ear drops, and cholesteatomas can be surgically removed.
Most often the cause of a child’s hearing loss cannot be reversed, and treatment involves use of a hearing aid to compensate for the impairment as much as possible.
Hearing aids are available for infants as well as older children. If hearing loss is mild or moderate or affects only one ear, a hearing aid or earphones can be used. Children who have hearing impairment in only one ear can be helped by using an FM auditory trainer that transmits a teacher’s voice to a hearing aid in the normal ear.
Hearing Aids: Amplifying the Sound
The behind-the-ear hearing aid is the most powerful but least attractive hearing aid. The in-the-ear hearing aid is the best choice for severe hearing loss. It is easy to adjust but is difficult to use with telephones. The in-the-canal hearing aid is used for mild to moderate hearing loss. This aid is relatively inconspicuous. The completely-in-the-canal hearing aid is used for mild to moderate hearing loss. This aid has good sound, is nearly invisible, and can be easily used with telephones. It is removed by pulling on a small string. However, it is the most expensive and hard to adjust. |
Cochlear implants (a surgically implanted system that sends electrical signals directly into the auditory nerve in response to sounds) may be used for children whose hearing loss is severe enough that it cannot be managed with hearing aids.
Children may also require therapy to support their language development, such as being taught a visually based sign language.
People in deaf communities are proud of their rich culture and alternative forms of communication. Many deaf people oppose surgery for the treatment of severe hearing impairment on the grounds that it may deny children membership in the deaf community. Families who wish to consider this approach should discuss it with their doctor.
More Information
The following are some English-language resources that may be useful. Please note that THE MANUAL is not responsible for the content of these resources.
See the following sites for comprehensive information about updates on research and funding initiatives, educational materials, support services, and quick links to related topics:
A.G. Bell Association for the Deaf and Hard of Hearing: Support, information, resources, and more to ensure people who are deaf and hard of hearing can hear and speak
American Society for Deaf Children: Information for children and youth of all hearing levels regarding access to communication support, language and learning opportunities, mentoring, and advocacy
Hearing Health Foundation: Information about preventing and curing hearing loss and other hearing disorders
Helen Keller National Center for DeafBlind Youths & Adults (HKNC): Information for how people who are blind, visually impaired, deaf-blind or have combined hearing and vision loss can live and work independently through training and other resources
National Association of the Deaf: A civil rights organization for deaf and hard-of-hearing people in the United States
