From a child’s birth, parents look forward to every milestone with great anticipation and excitement – rolling over, crawling, walking and talking. Out of these milestones, the ,ost subtle and easy to miss is the sense of hearing.
We asked Prof. Low Wong Kein, Head and Senior Consultant ENT surgeon, of the department of Otolaryngology in SGH, on the definition of hearing loss. He says,” You may hear the word ‘deaf’, ‘deafness’ or ‘hard of hearing’, when people talk about hearing loss. Hearing loss or hearing impairment is not an all or none phenomenon, where you are either stone deaf or have normal hearing; it is rather a continuum with many people having partial hearing loss.”
It happens when there is a problem with one or more parts of the ear (or ears) preventing proper hearing. It can be attributed to genes or acquired through disease or trauma to the ear. Hearing loss may affect one or both ears, and a person may be able to hear some sounds or nothing at all.
Early intervention can do wonders
According to Judith Simser, an auditory – verbal education director and consultant in childhood hearing impairment at SGH: “ It is important to realize that with newborn hearing screening, early fitting of hearing aids, and early intervention, the major of our deaf children can learn to listen, talk and attend normal schools with support services.”
To further stress her point she tells us:” My own son was born profoundly deaf but due to technological changes and an Auditory-verbal approach to develop his residual hearing, he has attended regular schools and today is a practicing lawyer.
The average age of diagnosis has always been between the ages of two-and-a-half and three. With medical advancements and implementation of newborn screening, we can now diagnosis the possibility of hearing impairment in children before the age of two months.
Currently Prof Low is working with the Ministry of Health to implement universal newborn hearing screening programmes in hospitals and polyclinics; and hopefully in the near future, a national programme can be established in Singapore. The screening programmes use oto-acoustic emission test, which is a simple and painless objective test. Costing about $30 per screening test, it is able to detect hearing loss by using a small probe near the child’s ear and takes about 10 minutes to perform.
Prof Low tells us: “The test can be performed in even one to two-day old infants. It is important to screen young babies so that any hearing impairment can be detected early. The authorities have recommended that hearing loss can be detected by three months of age and intervened soon after diagnosis, to optimize future speech and language development.
What causes hearing loss?
A child with conductive hearing loss may have been born with malformed parts of his outer or middle ear. Sometimes a tiny hole in the eardrum or even a buildup of earwax in the ear canal can cause conductive hearing impairment. Ear infections or middle ear fluid are also a common cause of this kind of hearing loss in kids.
Heredity or genes can cause sensory hearing loss. Sometimes, sensory hearing loss happens while an unborn baby is still growing – if a pregnant woman gets certain kinds of diseases or infections this can cause the developing baby to become hearing impaired. Also, a premature baby or profoundly jaundiced baby is more likely to suffer from hearing loss. Even oxygen therapy or treatment with antibiotics such as gentamicin can precipitate impaired hearing though this is rare. But it must be stressed that 50 percent of the time, the cause is unknown.
How does a doctor test for hearing loss?
If a doctor thinks that a baby or a child may have hearing loss, he or she will recommend that the parents take him to an audiologist. An audiologist is someone who is specially trained to test and help with the problem related to hearing loss.
A pediatric audiologist tests a child’s hearing by doing different types of tests. The tests that are used depend on the age of the child. A child can be tested for hearing loss at any age, beginning at birth.
What to look out for ?
Apart from the formal testing, parents can go look out for warning signs at home. Go through this checklist of hearing ‘milestone’: At birth, the baby is already startled by loud noises such as a clap and responds by blinking or opening his eyes widely in shock – these reactions can be picked up to check if the child is normal. At the tender age of one month, he should begin to notice sounds like a hair dryer and will pause to listen to them.
• By four months, he will become still or smile when u speak, even through you are out of his sight, he may also turn his head or eyes towards you if you creep up behind him and speak at his side.
• At seven months, he should immediately turn to your voice across the room or even to minor noises, if he is not otherwise occupied.
• By nine months, he listens attentively to everyday noises and will furtively search for very quiet sounds even if they are out of sight. He should also be babbling with glee by now in response to the stimulation of noise.
• By one year, your child will respond to his own name and can recognize familiar words. He may even respond to concepts such as “no”, “bye”, even if there is no accompanying gesture.
According to Ms Simser: “A child who is hard of hearing may turn to someone talking yet, not have sufficient hearing in all frequencies, for age appropriate speech and language to develop. At any time, there may be any number of children in regular classes with some degree of hearing impairment caused by middle ear problems or a partial sensorineural hearing loss. These children may appear inattentive and/or passive and less able to follow directions. They need to be referred for medical assessment and audiological testing immediately.”
How is hearing loss treated?
If a hearing loss is present in both ears, a hearing aid for each ear may be recommended. If hearing loss is presenting one ear only, a child may be fitted with an assistive listening device, such as an FM system. FM systems emphasize voices by making them louder and can help children hear better in crowded or noisy classrooms. In fact, the government supplies FM systems to children with hearing impairment who are integrated in regular schools.
Hearing aids work by using a tiny microphone to pick up sounds, an amplifier to selectively make these sounds louder, and a receiver – very similar to a sound system, only much smaller. The hearing aid delivers the amplified sounds via sound vibrations form the eardrum and middle ear to the inner ear or cochlea. Hearing aid technology is available which can adjust the volume of sounds automatically. An audiologist does special tests to determine which hearing aids will work best for each child.
For some children who are not able to hear or understand words even with the help of hearing aids, there is a device called cochlear implant or a bionic ear. This is very tiny piece of electronic equipment that is put into the cochlea during an operation. It uses electrical signals to stimulate delivery signals from the cochlea to the hearing nerve. It takes over the job of the damaged or destroyed hair cells in the cochlea by working directly with the hearing nerve. According to Prof Low, so far almost a hundred patients have undergone this procedure locally with encouraging results.
Can I teach him at home?
It is important to bring your child to the hospital for treatment if he has a hearing loss. Dealing with hearing impairment is a multidisciplinary job that needs the help of the otolaryngologist, the ENT doctor, the audiologist and the therapist speciallising in hearing impairment, among others. Moreover, on the financial front, the government now realizes the severity of the problem and is willing to partially subsidise cochlea implants, which can cost up to $27,000.
As Ms Simser puts it: “Cochlear implants can actually be a most cost effective surgical procedure. Individualized diagnostic therapy with parent participation is critical to teach a young child how to develop language through listening with the cochlear implant. If a deaf child develops spoken language and attends a normal school, even with support services, costs can be far less than having this child attend a special school for 14 to 15 years. However, special schools will always provide a necessary service for some deaf children to provide choices in methodologies to parents and their children.”
In Singapore, special schools for the hearing impaired are The Canossian School of the Hearing Impaired and the School of the Deaf as well as classes in two high schools. When assessed as an appropriate placement, deaf children with no hearing impairment. These children should use an FM system in the classroom.
If the hearing is not accessed in the critical language learning years, a child’s ability to use sounds meaningfully will deteriorate, due to physiological atrophy of the auditory pathways. This, in turn, will have a negative effect on his speech and language development. Without language, a child is unable to assess the school curriculum.
The thing to remember is these children – given early and effective intervention and environment – can become confident, capable communicators, go to college, hold good jobs, have families, and do almost any job the choose.
Good Habits :
1. Ensure that your child grows up in a good acoustic environment, this means an ideal listening environment without the distractions of a blaring television or computer. A child needs not only input but also interaction to develop language.
2. Read aloud to your children preferably in another quiet room, studies have shown that children read aloud to eventually become the best readers themselves.
3. Don’t underestimate the value of play with your child, even though this seems to have nothing to do with hearing. Children learn language most efficiently through consistent and continual interaction. The interaction will stimulate your child’s mental growth, which in turn accelerates his speech and language abilities. It also helps if you talk to them about useful, meaningful topics they can understand.
The original article appeared in Motherhood Magazine, By Leonard Yeo