Music to the ears of worried parents
'Bionic ears' offer deaf or hearing-impaired kids the gift of hearing
 
About eight months after he was born, baby Markus C finally heard his parents' voices clearly for the first time.

Markus, who was born with profound hearing loss in both ears, is one of the youngest children in Singapore to have received cochlear implants.

Also known as a bionic ear, a cochlear implant is an electronic device designed to help people who are deaf or have severe hearing loss.

While hearing aids amplify sound, a cochlear implant bypasses the damaged part of the ear and directly stimulates the auditory nerve to help the person "hear" sounds.

Associate Professor Lynne Lim, senior consultant and director of the Centre for Hearing Intervention and Language Development at the National University Hospital (NUH), performed the cochlear implants surgery on Markus last September when he was seven months old.

Bionic ears
Now, Markus has cochlear implants in either side of his skull. He wears an external sound processor, which is about the size of a 50-cent coin, behind both ears.

The external processor captures sound and converts it into digital signals to the internal implants. The internal implants then directly stimulate the auditory nerve, which delivers the signal to the brain, allowing sound to be "heard".

A month after Markus' surgery, an audiologist turned on the device, helping Markus enter the world of sound and speech.

Describing his son's reaction when the cochlear implants were activated for the first time, Markus' father, 38-year-old Peter C, said: "He smiled and turned around to find out where the sounds he heard were coming from."

According to Assoc Prof Lim, four of every 1,000 babies are born deaf in Singapore each year. At the NUH, more than 100 of such cochlear implantations have been performed on children over the past 10 years. The majority of them were done in the last five years.

Associate Professor Henry Tan, head and senior consultant of the Otolaryngology Department at the KK Women's and Children's Hospital, said that only children with profound hearing loss, which cannot be treated by hearing aids, are suitable for cochlear implantation.

Assoc Prof Lim explained that, while hearing aids may be useful for those with mild to moderate hearing problems, they will not help in cases of severe profound hearing loss.

For hearing-impaired babies, not being able to hear can lead to long-term problems. Said Assoc Prof Lim: "Children require near perfect hearing for speech, language acquisition and learning, which is especially crucial in the first four years of their lives."

Assoc Prof Tan added: "If you cannot hear, you cannot learn, so a child with complete hearing loss will be deaf and dumb. If the child has partial hearing loss, he or she will also have poor speech development."

For Mr and Mrs Peter C, such worries spurred them to consider the implants. They eventually paid a five-figure sum for their son's cochlear implants.

"It is very expensive but it is a small cost compared to what we can give our child. As parents, you want your child to be as normal as possible. We hope for Markus to grow up, having the same opportunities as his older brother," said Mrs C, 40, a homemaker. Markus' older brother is three-and-a-half years old and does not have any hearing problems.

Is implanting a child early always better?
According to Assoc Prof Lim, research has shown that implanting the child at an earlier age helps improve speech and language acquisition outcomes.

"I have implanted children who were below or at one year old delight us with age-appropriate language skills by two years old. Some families work so hard with their kids they are even ahead of their peers by three. That said, a lot of credit must go to the families, audiologists, therapists and school teachers who work very hard with the kids," she said.

On the other hand, Assoc Prof Tan said implanting a very young child has its risks. The youngest child to receive cochlear implants at KKH is 11 months.

"As a standard, as long as the child is implanted by or before two years, the child will do very well. The risk of implanting a very young child is that you may implant a child who actually has hearing or remnant hearing," he explained.

Parents must also be aware of the long-term follow-up care needed after the surgery.

Just three months after his cochlear implants were activated, and after countless sessions of therapy, Mrs C said Markus - now almost 11 months old - can hear almost as well as "any normal hearing child". He is also at the same level of speech development as babies in his age group.

"Looking at it positively, we were lucky that we found out (about his hearing problem) early and did something about it," said Mrs C.