What are hearing tests for children?

Hearing tests measure how well your baby or child can hear different sounds. Some babies are born with hearing problems. Other children are born with normal hearing and begin to have hearing problems later in childhood.

Hearing loss in infancy and early childhood can delay a child's ability to talk, understand spoken language, and develop social skills. Hearing tests can find problems early so that children with hearing loss can be treated and get help learning language skills as soon as possible.

Hearing depends on a series of steps that change sound waves into electrical signals that the brain understands as sounds. Hearing loss happens when there's a problem with any of these steps:

• Sound waves enter the outer ear and travel to the eardrum in the middle ear.
• The soundwaves vibrate the eardrum, which sends the vibrations to tiny bones that make the vibrations stronger.
• The vibrating bones make tiny waves in the fluid that's inside the cochlea. The cochlea is a snail-shaped structure in the inner ear. It is lined with sensory cells that have hair-like structures. When the hair cells move with the fluid waves, they create electrical signals.
• The auditory (hearing) nerve carries the electrical signals from the inner ear to the brain, which turns them into sounds you can recognize and understand.

There are three main types of hearing loss:

• Conductive hearing loss happens when sound waves can't reach the inner ear. Earwax or abnormal fluid in the ear may be blocking the path, or a hole in the eardrum may prevent it from vibrating. Ear infections are a common cause of this type of hearing loss in infants and young children. Medical treatment or surgery can often improve hearing.
• Sensorineural hearing loss (also called nerve deafness) happens when there's damage to the cochlea in the inner ear or the auditory nerve. This type of hearing loss ranges from mild (difficulty hearing certain sounds) to profound (not hearing any sound). The hearing loss is usually permanent, but it can improve with hearing aids or other devices.
• Mixed hearing loss is a combination of both sensorineural and conductive hearing loss.

One type of sensorineural hearing loss is called auditory neuropathy spectrum disorder (ANSD). With ANSD, there's problem with how the inner ear or the hearing nerve sends sound to the brain. This type of hearing disorder may happen if your child has health problems before or during birth or as a newborn. These problems include premature birth (being born too soon), low birth weight, and jaundice. ANSD may also be caused by a genetic disorder.

Other names: audiometry; audiography, audiogram, sound test

What are they used for?

Hearing screening tests are used to find out if a newborn, baby, or child may have hearing loss. These quick pass/fail tests show whether your child needs more testing. They can't diagnose hearing loss.

More complete hearing tests are used to diagnose hearing loss if your child doesn't pass a screening test, or if you have concerns about your child's hearing. These tests can show which type of hearing loss your child has and how severe it is.

Why does my child need a hearing test?

Routine hearing screening tests are recommended for all babies and children:

• Newborns should have a screening test for hearing problems by 1 month of age.
  • If you give birth in a hospital, the screening test is usually done before your baby goes home.
  • If you give birth at home, make sure to get your baby tested during the first month after birth.
• Children should have their hearing checked before they enter school. School-aged children may have hearing screening tests as part of their regular health checkups. The tests are often done in school, too.

More complete hearing tests are needed any time there is a concern about your child's hearing:

• If your baby doesn't pass the newborn hearing screening test, your baby will need complete hearing tests as soon as possible, but no later than 3 months of age.
• If your baby passes the newborn hearing screening test, but has a high risk for developing hearing loss, your baby will need complete hearing tests between 24 to 30 months of age. Your baby's risk may be higher if childhood hearing loss runs in your family or if your baby had certain infections. Ask your baby's provider about your baby's risk level.
• If your baby or child shows signs of hearing loss, contact your child's provider as soon as possible.

Signs of hearing loss in a baby include:

• Not jumping or being startled at loud noises
• After 6 months of age, not turning toward a sound
• By 12 months of age, not saying a few simple words, such as "dada" or "mama"

Signs of hearing loss in children include:

• Unclear speech
• Not following directions
• Often saying, "Huh?"
• Turning the TV volume up too high
• Learning problems

What happens during a hearing test?

Hearing tests depend on your child's age and ability to follow instructions:

Hearing screening tests for newborns, infants, and very young children can measure hearing without needing your child to cooperate. These tests can even be done while your child sleeps:

• Auditory brainstorm (ABR) tests check the inner ear, the hearing nerve, and parts of the brain that are involved with hearing. During an ABR test:
  • The provider will place electrodes (small sensors that stick to the skin) on the scalp. The electrodes are connected to a computer.
  • Tiny, soft earphones will be placed inside the ears.
  • The earphones will play sounds.
  • The electrodes measure how the brain responses to the sounds. The results are shown on the computer.
• Otoacoustic emissions (OAE) tests check for damage in the hair cells in the cochlea. During an OAE test:
  • A small device will be placed in the ear. It can make sound and measure sound.
  • Sound from the device makes the fluid in the cochlea ripple, which moves the hair cells. When the hairs move, they make vibrations that have their own sound called OAEs.
  • The device measures OAEs to see how well the hair cells are working. If the test shows little or no OAEs, your child may have sensorineural hearing loss.

Hearing screening tests for older children are usually audiometry tests. These tests check the quietest sounds or words that your child can hear. For these tests:

• Your child will wear headphones. If your child won't wear headphones, sounds may be played through speakers in a sound booth.
• For a pure-tone test, each time your child hears a tone they will raise their hand, push a button, or say that they heard the sound.
• For a speech test (also called speech discrimination testing), your child will hear simple words at different levels of loudness. Some words will be spoken over noise. Your child will repeat the words they hear.

Audiometry tests can be adapted for very young children and infants. For young children, the tests may include a game to help them pay attention to the sounds. For example, a child may put a block in a box each time they hear a sound.

For infants and toddlers, the provider will watch for behavior changes that show the child heard a sound. For example, an infant may start sucking a pacifier or look to see where the sound came from. When the child responds to a sound, they get to see a moving toy as a reward.

More complete hearing tests will be done if your child doesn't pass a hearing screening test. Your child's provider will usually refer you to a hearing specialist, such as:

• A pediatric audiologist, a health care professional who is trained to test hearing, diagnose hearing loss, and provide hearing devices and services to improve hearing in children.
• A pediatric otolaryngologist (ENT), a doctor who specializes in diagnosing and treating ear conditions in children. This type of provider may also be called a pediatric otologist.

During a complete hearing exam, your child may have several types of hearing tests that examine different parts hearing. These tests may include an ABR and/or an OAE test for children who were screened with audiometry tests. Other common tests include:

• Tympanometry. This test checks how well the eardrum and bones in the middle ear are working. Your child will need to sit very still, so this test usually isn't used for infants or young children. During the test:
  • A small device will be placed in your child's ear.
  • The device will send air and sound into the ear, which makes the eardrum move. Your child will feel the air pressure.
  • A machine records the movements of the eardrum on graphs called tympanograms.
  • If the eardrum doesn't move normally, your child may have fluid or wax buildup in the ear, a hole in the eardrum, a tumor in the ear, middle ear bones that don't vibrate well, or another problem in the middle ear.
• Acoustic Reflex Measures, also called middle ear muscle reflex (MEMR) test. This test shows how the ear responds to loud sounds. Normally, a tiny muscle inside the ear tightens to protect your ear when you hear loud noises. If unusually loud noises are needed to trigger the muscle to tighten, or if it doesn't tighten at all, your child may have hearing loss. To do the test:
  • A small device will be placed in your child's ear.
  • The device will make loud sounds.
  • A machine will show if the sound triggered the ear muscle to tighten.

Will I need to do anything to prepare for a hearing test?

There are no special preparations for a hearing test. But it's helpful to tell you child what to expect. Let your child know they will hear sounds. If you have a pair of headphones, you might let your child try them on to see what they feel like.

Are there any risks to hearing tests?

There is no risk to having hearing tests.

What do the results mean?

If your child's hearing screening test shows normal hearing, your child usually won't need more hearing tests until their next routine screening. But if you have concerns about your child's hearing or if your child has risks for hearing loss, talk with your child's provider about getting more complete hearing tests.

If the results of complete hearing tests show that your child has hearing loss, the results will also show how severe it is, which ear is affected more, and whether they have conductive sensorineural, or both types of hearing loss.

• With conductive hearing loss, treatment may be able to restore your child's hearing. The treatment will depend on what's blocking sound from reaching the inner ear. It may include removing wax, draining fluid, or doing surgery to fix problems with the eardrum or ear bones.
• With sensorineural hearing loss, the loss of hearing is permanent. But your child's hearing may improve with hearing aids or surgery to implant a device called a cochlear implant.

Other treatment and support options for hearing loss in children include:

• Working with professionals who can help children and their families learn to communicate. This may include learning sign language, lip reading, or other ways to communicate.
• Education to help your child learn communication skills.
• Assistive devices, such as devices for using the telephone and alerting your child to alarms, doorbells, and other sounds.
• Support groups.

If you have questions about your child's hearing and treatment, talk with your child's primary care provider or hearing specialist.

Learn more about laboratory tests, reference ranges, and understanding results.