• Hearing loss usually results from genetic defects in newborns and from ear infections or earwax in older children.
• If children do not respond to sounds, have difficulty talking, or are slow starting to talk, their hearing may be impaired.
• A handheld device or a test that measures the brain's responses to sounds is used to test hearing in newborns, and various techniques are used for older children.
• If possible, the cause is treated, but hearing aids are usually needed.

Hearing impairment is relatively common among children:

• Severe impairment at birth in about 1 in 1,000
• Less severe impairment at birth in about 3 in 1,000
• Development of hearing impairment before adulthood in about 4 in 1,000 children with normal hearing at birth
• Some difficulty hearing in about 19 in 100 children aged 0 to 19 years
• Hearing loss (mild, moderate, or severe) in one ear in about 55 in 1,000

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.

Causes

Genetic defects are the most common cause of hearing impairment in newborns. Ear infections, including secretory otitis media, and accumulation of earwax are the most common causes of hearing impairment in infants and older children. In older children, other causes include head injury, loud noise (including loud music), use of aminoglycoside antibiotics (such as gentamicin) or thiazide diuretics, certain viral infections (such as mumps), tumors or injuries that damage the auditory nerve, injury by pencils or other foreign objects that become stuck deep in the ear, and, rarely, autoimmune disorders.

Risk Factors for Hearing Impairment in Children
Newborns Low birth weight (especially less than 3.3 pounds, or 1.5 kilograms) Low Apgar score (lower than 5 at 1 minute or lower than 7 at 5 minutes after birth)—this score reflects the newborn's overall condition Low blood oxygen levels or seizures resulting from a difficult delivery Infection with rubella, syphilis, herpes, cytomegalovirus, or toxoplasmosis before birth Abnormalities in the skull or face, especially those involving the outer ear and ear canal A high level of bilirubin (a waste product) in the blood Bacterial meningitis Bloodstream infection (sepsis) Use of a ventilator for a long time Use of certain drugs, such as aminoglycoside antibiotics and some diuretics History of early hearing loss in a parent or close relative Older children All the above, plus the following: A head injury with a skull fracture or loss of consciousness Chronic otitis media with a cholesteatoma Some neurologic disorders, such as neurofibromatosis and neurodegenerative disorders Exposure to noise Perforation of the eardrum due to infection or injury

Did You Know... If children ignore people who are talking to them some but not all of the time, their hearing may be impaired.

Symptoms

Parents may suspect severe 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:

• Ignoring people who are talking to them some but not all of the time
• Being able to talk and hear well at home but not in school (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

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. This testing is required by law in many states.

Newborns are usually screened in two stages. First, children 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 child'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 children 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.

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

Treatment

Treating some causes of hearing loss 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. Children with a mild or moderate hearing impairment in one ear usually need an FM radio system that transmits a teacher's voice directly to a set of speakers, hearing aids, or earphones. Cochlear implants (devices placed in the inner ear to stimulate the auditory nerve with an electrical current in response to sounds) are used for most children with severely impaired hearing (see Hearing Loss and Deafness: Treatment in Children).

People in deaf communities are proud of their rich culture and alternative forms of communication. Many people oppose the aggressive treatment of hearing impairment on the grounds that it denies children the opportunities available in those communities. Families who wish to consider this approach should discuss it with their doctor.

Last full review/revision January 2009 by Robert J. Ruben, MD