About Child’s Hearing
Many children under the age of 18 have some hearing loss including four out of every thousand newborns. Hearing loss can increase the risk of speech and language developmental delays. So, every parent and caregiver should be aware of the signs of hearing loss in his/her child and seek a professional diagnosis.
How the Ear Works
The ear has three main parts: the outer, middle and inner ear – please see the picture for more detail. The outer ear (the part you can see) opens into the ear canal.
The eardrum separates the ear canal from the middle ear. Small bones in the middle ear help transfer sound to the inner ear. The inner ear contains the auditory (hearing) nerve, which leads to the brain.
Any source of sound sends vibrations or sound waves into the air. These funnel through the ear opening, down the ear, canal, and strike your eardrum, causing it to vibrate.
The vibrations are passed to the small bones of the middle ear, which transmit them to the hearing nerve in the inner ear. Here, the vibrations become nerve impulses and go directly to the brain, which interprets the impulses as sound (music, voice, a car horn, etc.).
Indicators for hearing loss
During pregnancy
- Mother had German Measles, a viral infection or the flu
- Mother drank alcoholic beverages
Newborn
- Weighed less than 1.5 kg at birth
- Has an unusual appearance of the face or ears
- Was jaundiced (yellow skin) at birth and had an exchange blood transfusion
- Was in neonatal intensive care unit (NICU) for more than five days
- Received an antibiotic medication given through a needle in a vein
- Had meningitis
- Failed newborn hearing screening test
Family
- Has one or more individuals with permanent or progressive hearing loss that was present or developed early in life
Infant
- Received an antibiotic medication given through a needle in a vein
- Had meningitis
- Has a neurological disorder
- Had a severe injury with a fracture of the skull with or without bleeding from the ear
- Has recurring ear infections with fluid in ears for more than three months
Response to the environment – speech and language development
Newborn (Birth to 3 Months)
How to tell if your child’s hearing is normal – some signs there may be a problem with your child’s hearing
- Does not startle, move, cry or react in any way to unexpected loud noises
- Does not awaken to loud noises
- Does not freely imitate sound
- Cannot be soothed by voice alone
- Does not turn his/her head in the direction of your voice
- Does not point to familiar persons or objects when asked
- Does not babble or babbling has stopped
Infant (3 months to 2 years)
- Does not accurately turn in the direction of a soft voice on the first call
- Is not alert to environmental sounds
- Does not respond on first call
- Does not respond to sounds or does not locate where sound is coming from
- Does not begin to imitate and use simple words for familiar people and things around the home
- Does not sound like or use speech like other children of similar age
- Does not listen to TV at a normal volume
- Does not show consistent growth in the understanding and the use of words
- By 12 months does not understand simple phrases by listening alone, such as “wave bye-bye,” or “clap hands”
Hearing tests: How, when, and why
If you suspect that your child may have hearing loss, discuss it with your doctor. Children of any age can be professionally tested.
Tests for newborns and infants under one year
Hearing tests are painless, and they normally take less than half-an-hour.
Newborns are tested with either the otoacoustic emissions (OAE) test or the automated auditory brainstem response (AABR) test. During the OAE test, a microphone is placed in the baby’s ear. It sends soft clicking sounds, and a computer then records the inner ear’s response to the sounds. In the AABR test the child must wear earphones. Sensors are placed on his/her head to measure brain wave activity in response to the sound.
For infants over six months of age, the diagnostic auditory brainstem response and the visual reinforcement audiometry (VRA) tests are commonly used. The diagnostic auditory brainstem response test is similar to the AABR test, but it provides more information. The VRA test presents a series of sounds through earphones. The child is asked to turn toward the sound, and then he/she is rewarded with an entertaining visual image.
Tests for older children and adults
Children between two and four years old are tested through conditioned play audiometry (CPA). The children are asked to perform a simple play activity, such as placing a ring on a peg, when they hear a sound. Older children and adults may be asked to press a button or raise their hand.
All children should have their hearing tested before they start school. This could reveal mild hearing losses that the parent or child cannot detect. Loss of hearing in one ear may also be determined in this way. Such a loss, although not obvious, may affect speech and language.
Hearing loss can even result from earwax or fluid in the ears. Many children with this type of temporary hearing loss can have their hearing restored through medical treatment or minor surgery.
In contrast to temporary hearing loss, some children have nerve deafness, which is permanent. Most of these children have some usable hearing. Few are totally deaf. Early diagnosis, early fitting of hearing aids, and an early start on special educational programs can help maximize the child’s existing hearing.
Please note that this information is not a substitute for an ear examination or a hearing test.
What you should do
If you have checked one or more of these indicators, your child might have hearing loss and you should take him or her for an ear examination and a hearing test. This can be done at any age, as early as just after birth.
If you did not check any of these factors but you suspect that your child is not hearing normally, contact your local doctor who will arrange for you to see an ear nose throat specialist and have your child’s hearing tested by an audiologist and when appropriate, have his or her speech evaluated by a speech and language pathologist.