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April 15, 2005

The wonderful gift of sound-I

From: Deccan Herald - Bangalore,India - Apr 15, 2005

It's come as a boon for people with severe hearing loss. One cannot help but marvel at the technology behind cochlear implants, says Bharati Prabhu.

As Helen Keller so aptly put it, while visual disability isolates one from things, hearing disability isolates one from people. Though very limited, training facilities for the visually and hearing impaired exist in our country. Excellent facilities for treating hearing impairment exist in most metros. Many people now know that hearing impaired children are not "dumb" and that they can be taught to speak and function well in a hearing world.

But not many people know about cochlear implants. While hearing aids have traditionally been prescribed to those with hearing impairment, there is a large group of children and adults with severe to profound hearing loss who don't derive significant benefit from these sound amplification devices. It is to this population that a cochlear implant comes as a boon.

A cochlear implant is different from a hearing aid. It does not amplify sounds but digitises and codes the sound signals into electric signals. The cochlear implant system consists of external and internal parts. The external part has a microphone, which sits behind the ear and picks up sounds. It also has a processor to digitise and code sounds. There is a transmitter, which is held in place over the internal receiver by a pair of magnets, one in the center of the transmitter and the second located under the skin as part of the receiver in the internal system. The internal part consists of this receiver that is surgically placed inside the skull and an electrode array placed in the cochlea. This receiver converts the codes received from the external transmitter to electronic signals and sends it to an electrode array. These electrodes stimulate the hearing nerve and a sensation of sound is experienced.

The words surgery and implants scare people. But doctors assure that cochlear implantation is safe. Thorough medical and audiological evaluations are done prior to the surgery to ensure suitable candidacy. The surgery in itself lasts for about three hours with subsequent hospitalisation for three days. The processor is switched on and tuned three weeks later. The tuning process needs to be repeated a couple of times. Much research and development has gone on over the past few decades to ensure that cochlear implantation and the subsequent habilitation procedures yield maximum benefit to the recipient. Experts stress that learning to listen takes time and requires concerted efforts from the implantee, the family and the person providing habilitation services. But the results are often highly rewarding.

Little children develop age appropriate speech language skills and are integrated into the mainstream. Adults use the phone and function confidently in a hearing world. There are now over 575 cochlear implant recipients in India.

What about the long-term effects of having implants in the body? Cochlear implants are made from the safest materials and there are individuals who have had implants for over 20 years now without any adverse effects. Holly McDonnell received her implant in 1987 as a four year old. Now, studying law, the young lady leads a comfortable life. She is also the beneficiary of all the technological advances in cochlear implants that have taken place over the years.

Backward compatibility, practiced by manufacturers ensures that technology upgrades benefit all the implantees equally.

Victorija, Holly's mother often visits India in her capacity as a paediatric habilitation coordinator with Cochlear, a leading manufacturer of cochlear implants. Victorija stresses that younger the child, greater the benefits from the implants. Older children and adults too benefit but having got used to lip reading, the results may not be equally good.

Artist Satish Gujral received a cochlear implant at 71 years of age. Hearing sounds after 62 long years of silence, the artist slowly learnt to attach meaning to sound. But he also gradually realised that he preferred silence and had the implant removed. Interestingly, prior to cochlear implant, the artist says, his paintings were mostly in shades of dark and light. Post-implant, the artist's paintings took on vibrant colours! An example of how one sense affects another.

The cost of the implant (about Rs 5-8 lakh) is a big deterrent for the average Indian. Parent groups, specialists, insurance companies and the government, all need to work towards making cochlear implants affordable.

But hearing five-year-old Rahul (with an implant) declare that he wants to be a doctor and seeing him turn around when his therapist makes a soft sound, one can't help but marvel at the technology and the people who made this possible.

A few leading hospitals in Bangalore like Sagar Apollo Hospital (080-2653 6700 — 08), Basavangudi ENT Care Centre (080-26604569) and Institute of Speech and Hearing (080-25460405) carry out the procedure. Post implant training is also available.

Body-worn speech processor

Real time feedback

The LCD display shows whether the processor is functioning and a small indicator light reassures that sound is being received.

Sound equaliser

The unique performance enhancer, Adaptive Dynamic Range Optimisation (ADRO) works much like a graphic equaliser, boosting soft sounds in quiet and making loud sounds comfortable in noise.

Lockable controls

Easy to set lockable controls prevent infants and young children from adjusting the settings and disrupting their hearing.

Easy choice

There's a choice of disposable or rechargeable batteries that can be interchanged without replacing the battery compartment.

For more details on cochlear implants log onto or contact Pika Medical on 25594757.

Copyright 2005, The Printers (Mysore) Private Ltd.