| Can Your Baby Hear You? The birth of a healthy | | | | of blood cells-often causing jaundice in the newborn.) |
| baby is a miracle. The child emerges with ten fingers | | | | Hypoxia (low oxygen levels) Intraventricular |
| and toes, perfectly formed to touch and kick in a big, | | | | hemorrhage (bleeding within the brain.) |
| new world. Nose and taste buds yearn for the first | | | | 2. Conductive This is caused by problems with the |
| meeting with mother's nutritious milk. A baby even | | | | outer ear, middle ear, the tympanic membrane, or |
| opens its eyes trying to focus on the blurry faces of | | | | the bones of the ear and affects all frequencies |
| parents looming close, cooing their hellos and | | | | equally. This may also be due to congenital |
| declarations of love. | | | | cholesteatoma (growth in the middle ear.) |
| "Wait," thinks 1 baby out of 1,000. "Something is | | | | 3. Sensorineural This is caused by problems in the |
| missing. You're cooing and kissing but I can't hear a | | | | inner ear or auditory nerve. About 50% of these are |
| thing!!??" Indeed, no adults seem to notice that in | | | | due to various genetic diseases and syndromes |
| spite of all this activity, all is silent to the baby. | | | | (Alport's Syndrome, Turner's, Usher's, Waardenburg's |
| After the birth, our baby is pulled out of its mother's | | | | syndrome). Scientists have now mapped genes that |
| warm and protective arms into the hands of a | | | | cause hereditary hearing loss, in families. In 20-30% |
| pediatrician for examination. Seemingly, with a fine | | | | of cases, sensorineural defects can also be due to |
| tooth comb, he makes sure that all is complete and | | | | infectious causes such as cytomegalovirus ( most |
| well, and that there are no defects or deficiencies to | | | | common), group B strep infections, herpesvirus, |
| be addressed before the baby leaves the hospital. | | | | rubella, toxoplasmosis, and syphilis. Mothers can |
| The physician looks into every opening, fold and | | | | acquire these infections during pregnancy and pass it |
| crevice, tests the limb joints and reflexes, listens for | | | | to the fetus in utero. Children can show no signs at |
| the heartbeat and breathing, and almost always gives | | | | birth but go on to develop deafness later on in life. |
| the delighted parents the clean bill of health, | | | | Unknown causes (idiopathic) and anatomic causes are |
| congratulations and the measuring tape with the | | | | also in this category. |
| baby's length noted. | | | | 4. Mixed This includes a combination of the above |
| Why was this baby, and nearly 50% of all babies | | | | etiologies. |
| with later-discovered hearing issues, sent home from | | | | What are the most common tests used for |
| the hospital after delivery with undetected hearing | | | | screening? |
| loss? The reason is that hearing loss detection tests | | | | There are 2 infant tests available called the AABR |
| were not routinely performed on infants until | | | | and the TEOAE. Both diagnose sensorineural hearing |
| recently, when Government sponsored universal | | | | loss in newborns. There is no evidence that one test |
| screening programs were initiated for newborns. | | | | is superior to the other to date, although some |
| Why is it important to identify infants with hearing | | | | studies have shown a lower rate of false positives |
| loss? | | | | with AABR. Children with positive testing are referred |
| The ability to detect hearing problems in newborn | | | | for further testing and details are obtained about |
| infants is crucial. Studies have shown that being able | | | | genetic and family history. |
| to process auditory information early in life is crucial | | | | |
| for later development of reading and spoken | | | | 1. Automated brainstem response (AABR) This |
| language skills. Hearing loss is associated with social | | | | checks the auditory pathway from the outside ear |
| and emotional developmental lags in children as well | | | | to the lower brainstem. Infants have their ears |
| as poor academic achievement. | | | | covered with earphones that emit a series of clicks. |
| What is the incidence of congenital hearing loss? | | | | Electrodes on the infants forehead and neck measure |
| Congenital hearing loss can be found in two to three | | | | brain wave activity in response to the clicks which is |
| infants per 1,000 live births. That means that there | | | | then fed into a computer that assess the brain wave |
| are approximately 5,000 babies born in the United | | | | activity. |
| States each year with bilateral permanent hearing | | | | 2. Transient evoked otoacoustic emissions (TEOAE) |
| loss. | | | | This test evaluates the function of the cochlea by |
| How do you define hearing loss in newborns? | | | | placing a small microphone in the external ear canal |
| Newborns are checked for moderate to severe | | | | and testing the echo responses to a series of clicks |
| bilateral permanent hearing loss. Current testing after | | | | which is then placed thru a computer and compared |
| birth does not pick up loss that is progressive or | | | | to the standard.With any kind of testing, the |
| acquired later in life. The current testing programs | | | | important issue is the false positive and false |
| detect hearing losses at a threshold of 30-40 dB in | | | | negative rates. Universal newborn screening has a |
| the frequency important for speech recognition | | | | high number of false positive rates, mostly due to |
| (500-4,000 Hz) | | | | motion artifacts. Other causes of false positives can |
| What are the characteristics of children that are | | | | be due to fluid in the ear or ear infections. False |
| most likely to have hearing loss? | | | | positive rates can be as high as 30% with a one step |
| Babies who were determined to be at high risk for | | | | test, to less than 1% if a child is tested twice. If a |
| hearing loss include children that were admitted to | | | | child fails the test twice, an ear, nose, and throat |
| the neonatal intensive care unit for more than 2 | | | | referral is directed by the pediatrician. |
| days, (1-2 cases of hearing loss for every 200 | | | | Proper counseling of the parents allays the anxiety |
| babies), premature infants, children with craniofacial | | | | caused by false positives. The overall benefit far |
| anomalies, family history of hearing disorders, children | | | | outweighs the risks of missing a potentially deaf child |
| whose mothers developed infections in utero, and | | | | with delayed intervention. |
| children who are born with certain syndromes. | | | | What are the future goals to improve the medical |
| However, it was found that close to half of all the | | | | care of infants with hearing loss? |
| children not in the high risk group were missed. | | | | Future goals include devising a system for providing |
| Therefore, about 50% of all children with hearing | | | | better follow-up care on children who do not pass |
| problems were sent home from the hospital with | | | | the initial screening and for screening children that fall |
| undetected hearing loss. | | | | below the threshold and have milder forms of hearing |
| What are the current state requirements to have | | | | loss or late onset and progressive forms of hearing |
| children checked prior to leaving the hospital? | | | | loss that can be missed. Also, ensuring that children |
| Currently in all 50 states, Guam, and the District of | | | | with documented disorders are enrolled in intervention |
| Columbia regulations direct testing of all children for | | | | programs is critical. Children that have risk factors |
| hearing loss before leaving the hospital. All states and | | | | should not only be screened at birth but again |
| US territories have Early Hearing Detection and | | | | throughout childhood. |
| Intervention (EHDI) programs funded by the Federal | | | | Recommendations by the Joint Committee on Infant |
| Government which delineate the screening protocols, | | | | hearing recommends testing every 6 months before |
| follow-up care and collection of data. This data | | | | 3 years of age in high risk children. More Federal |
| collection has been initiated only since the year 1999. | | | | programs are being initiated to track follow-up care |
| The US Department of Health and Human Services | | | | on infants and to increase education and awareness. |
| now has clear guidelines which include a universal | | | | Summary: |
| protocol that screening should occur before 1 month | | | | Hearing loss detection in infants has markedly |
| of age, follow-up for infants not passing the test no | | | | changed in the last decade, with over 95% of all |
| later than 3 months of age and follow-up intervention | | | | newborns being screened. Follow-up interventions and |
| prior to 6 months of age for infants identified with | | | | enrollment in programs still remain a challenge. The |
| hearing loss. Due to initiation of these programs, the | | | | Federal programs now in place, with universal testing |
| number of infants screened for hearing loss increased | | | | and better data collation and tracking systems, are |
| from 46.5% in 1999 to 97% in 2007. | | | | expected to bring vast changes. Improvements in |
| What are some of the causes of hearing loss in | | | | overall quality of life will occur as a result of earlier |
| infants? | | | | detection and treatment as children avoid limitations in |
| Hearing loss can be divided into 4 categories: | | | | speech, language, and cognitive capacity. Hopefully |
| | | | this will obviate the damage caused by hearing |
| 1. Central This is due to deafness caused by | | | | limitations that affect academic performance, social |
| problems along the auditory pathway to the brain or | | | | interaction and deficits that negatively impact ability |
| in the brain. High levels of bilirubin (breakdown product | | | | to work. |