Screening all newborns for hearing problems could make a big difference in kids’ lives. If your baby does have hearing loss, it is important to catch it early. Babies begin to develop speech and language in the earliest months of life. Hearing impairment can interfere with language and speech development and the sooner the problems are identified, the sooner the kids can start programs to help them develop to their full potential. There are other advantages too: the tests may also help identify babies at risk for sudden infant death syndrome (SIDS.)
Modern technology has enabled many tests to be performed on newborn babies, which parents can avail before leaving the hospital. Unfortunately, many parents are still unaware of them. Traditionally, the parents suspect a hearing problem only when the child does not meet appropriate language development milestones. Some parents wait for as long as two or three years and the subsequent late diagnosis results in significant speech, language and cognitive delays, but a more observant parent can suspect hearing loss much earlier. You should schedule a hearing test if the baby doesn’t react to sound - doesn’t get startled or stop sucking or crying when there is a new sound or the baby doesn’t make eye contact even at the end of three months, or doesn’t babble at one year of age.
The following are the two tests performed on newborn babies even before they can leave the hospital:
* Otoacoustic emissions (OAE): In the late 1970s it was first discovered that for each sound which is heard by the ear, the ear itself produces a tiny corresponding sound. This ‘echo’, known as an otoacoustic emission, forms the basis for this screening test. A tiny, flexible plug that is inserted into the baby’s ear. Sounds are sent through the plug. A microphone in the plug records the otoacoustic emissions (responses) of the ear in reaction to the sounds. There are no emissions in a baby with hearing loss. This test is painless and is usually completed within a few minutes, while the baby sleeps. Average cost: $30.
* Auditory Brainstem Response (ABR): In the ABR test, some sounds are played through earphones that are placed on the baby’s head, usually when she is asleep. Band-aid like sensors attached to various locations on the child’s head record the electrical activity from the acoustic nerve and in other parts of the brain involved in hearing. The computer compares the response from the baby being to a “normal” response for babies. If the match is not close enough, the baby is referred for repeat screening. It does not necessarily mean your baby has a hearing loss. A newborn with normal hearing may fail the first screening due to debris in the ear canal, fluid in the middle ear or moving/crying during the test. Testing usually takes less than one hour. This is a highly specialized test requiring an experienced professional. Average cost: $75-$125.
In addition to the above two tests, older children can undergo the following tests:
* Behavioral Tests : Behavioral hearing tests are used with children who are able to respond to sounds either by turning their head or by playing a game. For young children there are usually two evaluators, an audiologist outside the sound booth monitoring the testing and another one inside who plays games with the child. Sometimes a parent is allowed inside the booth as well. Testing usually takes less than one hour.
Behavioral tests measure the degree of hearing loss and assist in locating the source of the problem. There are three types of behavioral tests:
1. Threshold testing measures the quietest tones or speech that a child is able to hear.
2. Word Recognition testing measures the child’s ability to understand speech at comfortable loudness levels.
3. Middle Ear testing searches for the presence of fluid or other middle ear dysfunction. The results are presented in a diagram called a tympanogram.
Children may need to be tested more than once, sometimes by different professionals. Swift intervention and diagnosis will help stem further delays of speech, language and cognitive development.