Hearing Loss in Infants and Newborns
Hearing anomalies in children do not only make the child deaf but also the child fails to develop speech and language skills although he does not have any defect in his speech organs. This is simply because the child fails to hear speech and thus fails to acquire age appropriate speech and language skills. If the child has a lesser degree of hearing loss, then the speech does develop but is defective. First 5 years of the child are very important for the development of speech and language, therefore it is very important that any disability in hearing be detected and managed as early as possible. The importance of early identification and treatment cannot be stressed enough.
WHY IS THE CHILD DEAF? WHAT IS THE CAUSE?
The causes of child deafness or hearing loss are variable and vast. They may occur during the fetal period while the baby is still in the mother’s womb, during the procedure of birth or after birth.
When the baby is in the mother’s womb, he may develop ear anomalies due to genetic or non-genetic causes. Defects occur in the inner ear, middle ear and the external ear. They may be part of a syndrome or can occur separately.
Mother during her pregnancy is very vulnerable to develop anomalies in her child if she is exposed to certain drugs and chemicals or by developing infections. Infection by toxoplasma, rubella, cytomegalovirus, herpes 1 and 2 and syphilis all can cause hearing loss in the child if the mother is affected during pregnancy. Drugs that are dangerous to fetus’ hearing mechanisms include streptomycin, gentamycin, tobramycin, quinine or chloroquine and thalidomide. These drugs should be avoided during pregnancy. Radiation exposure of the mother during first trimester and other causes such as nutritional deficiency, diabetes and thyroid deficiency all can result in infant hearing loss. Maternal alcoholism should also be avoided.
During birth, the child’s ear may be injured by forceps or the child can acquire meningitis which can lead to hearing loss. Premature and low birth babies have more chances of being born with hearing deficiencies.
After birth, the infant or child can acquire viral infections such as measles, mumps, influenza, meningitis which can lead to deafness. Ear toxic drugs are also dangerous as well dangerous levels of noise can lead to noise injury of the ear and subsequent damage to hearing apparatus.
HOW DO YOU KNOW ABOUT INFANT HEARING LOSS
Usually if the anomaly is not visible at birth, the hearing loss is not detected at the time of birth but certain behavior of the child can raise suspicion among the parents or other close family members that there is something wrong. The child may not respond to loud noises for example, the child may not show any startling response to loud sounds .In normal cases the infant may show startling responses and starts to cry if the noise is too loud but this is absent or diminished in a defective child. The child may sleep through loud noises. Similarly, the baby may not respond to playful sounds by the relatives or may not respond to name calling or show any head turn responses. If such behavior fails to get noticed then as the child grows older, he may fail to develop age appropriate speech and language . If left untreated it may affect the child’s performance in school.
HOW TO ASSESS THE HEARING OF INFANTS OR CHILDREN?
There are certain screening procedures that can be used in case of ‘’high risk’’ infants..These include Otoacoustic emissions (OAEs) and auditory brainstem responses (ABR). Nurses in hospitals trained in screening children with hearing impairment now routinely perform these tests at birth. If these children fail the screening at birth they are referred to an audiologist who would perform further diagnostic tests to determine hearing loss.
Besides objective tests Audiologists can assess children’s hearing through behavioral techniques to determine the type and degree of hearing loss.
WHAT TO DO IF THE CHILD HAS HEARING LOSS?
Management of the condition includes parental guidance. It is emotionally hard on the parents when they find out about infant’s deafness and they should be counseled and informed sympathetically. They should be made aware of the demands of their hearing impaired child and given guidance on how to deal with them.
To begin with Children need to be fitted with hearing aids and should receive intensive rehabilitation to maximize their residual hearing. Cochlear implants may also be a possibility if the defect lies in the cochlea. Their rehabilitation and management is tough but it is very important for their ultimate development into maximally functional individuals of society.