Pediatric Advisor 10.0: Hearing Loss

Clinical Reference Systems: Pediatric Advisor 10.0

Hearing Loss

What is hearing loss?

A hearing impairment refers to all degrees of hearing loss. Types of hearing loss are classified by where in the ear the problem occurs and the severity of loss.

What are the types of hearing loss?

Conductive hearing loss
A conductive hearing loss results when something interferes with sound waves traveling through the outer and middle parts of the ear. Causes of conductive hearing loss include:

complete blockage in the outer ear by wax
infection in the middle ear (otitis media)
damage to the tiny bones in the middle ear.
Sensorineural hearing loss
A sensorineural hearing loss results from a problem in the innermost part of the ear or in the auditory nerve (the term auditory refers to hearing). Causes of sensorineural hearing loss include:

diseases, such as meningitis and rubella
tumors
abnormal development of the inner part of the ear and other genetic conditions
physical injury to the inner ear.

Sensorineural hearing losses are permanent. Sometimes the problem with the inner ear also causes problems with balance. Children with both hearing and balance problems may have mild delays in the development of their motor skills.
Mixed hearing loss
A child may have both a sensorineural hearing loss and a conductive hearing loss. This type of hearing loss is called a mixed loss.

What are the levels of severity?

Hearing losses are also classified by their severity: mild, moderate, severe, and profound. The level of severity is determined by the loudness of sound that a child can hear without a hearing aid. The loudness of sound is measured by decibels (dB).

Mild: Children with mild hearing losses can hear sounds of 20 to 40 dB or louder. They may have trouble hearing faint or distant speech. The most common cause of a mild hearing loss is fluid collection in the middle ear, a conductive hearing loss.

Moderate: Children who have moderate losses of hearing can hear sounds louder than 45 to 60 dB. They need speech to be loud. It is hard for these children to understand speech in group situations.

Severe: Children with severe losses can hear sounds of 65 to 85 dB or louder. They can hear only loud voices one foot or less away, or loud sounds in the environment.

Profound: Children with profound hearing losses may hear loud sounds of 90 dB or more, but they may be more aware of vibrations than sound. The term deaf usually applies to children with profound hearing losses or to children with no hearing at all.

Children with hearing loss that crosses two levels of severity are given the label of both; for example, mild to moderate hearing loss, or moderate to severe.

How and when should my child be tested?

Early testing is important in helping a hearing-impaired child adapt to the hearing world. Every child who may have a hearing loss needs thorough testing of his hearing and middle ear function. A child is never too young to have a hearing test.

An audiologist performs hearing tests. He or she is specially trained to recognize and evaluate hearing. If necessary, an audiologist can fit your child with a hearing aid.

After a hearing loss is diagnosed, health care professionals will try to find out the cause of the hearing loss. They will also look for related problems or disabilities. Additional tests may include blood tests, an EKG, and a CAT scan (a special x-ray) of the middle and inner ear.

Results from these tests help determine the best treatment and educational strategy for your child. Tests can be taken in a special center for assessing disabled children, or by a team of professionals your pediatrician selects. The professionals may include an otolaryngologist (a doctor who specializes in the ear, nose, and throat problems), an ophthalmologist (an eye doctor), a developmental pediatrician, a geneticist, a speech/language pathologist, a psychologist, and a learning specialist.

Hearing-impaired children need regular hearing and ear exams. Typically, audiologists see younger children more often than older children because their ear canals are growing and changing shape. Young children may often need new ear molds for holding the hearing aid in place.

Call your child's doctor if there is any sudden change in your child's response to sound, especially from a cold. The change may signal a middle ear problem. A buildup of fluid in the middle ear could worsen your child's hearing loss. Most doctors put ventilating tubes (ear tubes) in children who have a sensorineural hearing loss and fluid in the middle ear. Any additional hearing loss may make a big difference in what a child can hear. A child with ear tubes can continue to use hearing aids.

What is the treatment?

A child's early years are very important for learning and the development of language. Treating hearing impairment early makes a big difference in how well a child functions later in life. The audiologist tries to provide the best use of a child's remaining hearing. She or he designs a treatment plan for your child. This plan consists not only of making sound louder with hearing aids, but also hearing and language training, and parent support and training.

Hearing aids

Hearing aids do not restore hearing. They are loudspeakers that help get the best sound possible to your child's ear. The aid makes sounds louder, not clearer. It may distort some sounds.

A very important aspect of treatment is teaching your child how to hear better; for example, by ignoring noises in the environment and paying attention to voices. Make sure that you talk to the audiologist about what sounds your child can hear with and without a hearing aid, the effects of noise on your child's hearing, and how to keep the hearing aids in the best working order.

Children of all ages can use hearing aids. The aids even help young infants.

Cochlear implants

The cochlea is the part of the ear that turns the vibrations we call sound into electrical signals. The brain then interprets the electrical signals into meaningful sounds such as speech. Some children with profound hearing loss may benefit from an electronic device called a cochlear implant (CI).

A CI consists of three parts: a microphone, a microcomputer, and a cochlear electrode. The microphone, worn behind the ear, sends the sound to a microcomputer. The microcomputer is connected to the microphone by a wire and is worn in a pouch attached to the belt. It turns the sound into an electrical code which is sent by radio wave to the cochlear electrode. The wire electrode is surgically implanted through the skull behind the ear into the cochlea. The cochlear implant does not give the child normal hearing. However, the child may be able to interpret the signals produced by the implant after he or she gets used to the signals and what they mean.

Children with cochlear implants still need the therapies listed below.

Therapies
Language training programs for hearing-impaired children are offered as early as infancy. Parent-infant programs help parents provide an environment rich in language for their child.
Hearing-impaired children use a variety of ways to communicate. You will need to decide which way works best with your child.
Auditory oral approach: The auditory oral approach trains children to make the most of their speech and hearing abilities. It works best with children who have a lot of hearing left.
Total communication: The total communication approach uses speech, hearing, vision, speech-reading, finger spelling, reading, writing, and signing (American Sign Language).
The best approach for a child depends on such factors as:

the severity of the hearing loss
when the hearing loss occurred
the type of hearing loss
when the hearing loss was diagnosed
what the child has learned already about speech and language
parent-child interaction
educational needs.

Think about and discuss the following questions to help determine the best method of communication for your child:

How much hearing does your child have left?
How does your family communicate with your child?
Are you willing to attend sign language classes?
What resources are available to you and your child?

How can I help my child learn to communicate?

Talk directly to your child. Always face your child and bend down to his or her level before you begin to speak. Use short, simple phrases and sentences. Don't use baby talk. Speak clearly and not too fast.
Use a lot of facial and body expressions.
Talk about things that are important to your child. Provide materials, toys, and games that are interesting to your child to stimulate conversation.
Repeat words and phrases often. As part of your child's daily routines--for example, getting dressed--emphasize words like shirt, socks, shoes. Add words to your child's one- and two-word phrases. For example, when your child says "blue train," say back to the child, "The blue train is going fast."
Encourage your child to join in your conversation. Praise your child's efforts at making sounds. Respond to the meaning your child is trying to communicate. Encourage taking turns in conversation.
Avoid having conversations in places where there is a lot of noise, including sound from television, radio, electrical appliances, and competing conversations.

SUPPORT ORGANIZATIONS FOR PARENTS

 
Alexander Graham Bell          American Society for Deaf 
 Association for the            Children 
 Deaf, Inc.                    814 Third Ave.  
347 Volta Place, NW            Silver Spring, MD 20910 
Washington, DC 20007 
                               Boys Town National Institute 
American Speech-Language-       for Communication Disorders 
 Hearing Association            in Children 
10801 Rockville Pike           555 North 30th St.  
Rockville, MD 20852            Omaha, NE 68131 
www.asha.org
                               International Association for 
Children's Hearing Education    Parents of the Deaf (IAPD) 
 and Research (CHEAR)          814 Thayer Ave.  
871 McLean Ave.                Silver Spring, MD 20910 
Yonkers, NY 10704 
                               SKI Hearing Impaired Outreach 
National Information Center    Utah State University 
 on Deafness                   Logan, UT 
Gallaudet University 
800 Florida Ave. NE 
Washington, DC 20002-3695