Kaushik Gandhi’s bold ears add to his impish look but not to his hearing. The little boy, who turns three on Friday, has laughter in his eyes; a babble that belies his age; and is altogether endearing, especially when they play a video of him taking a lesson with his speech therapist. He points to himself on the screen and says “yaay!”
A short word, maybe just a noise, but for Kaushik to merely make that sound is an achievement. For someone who was born without the tools of hearing –the inner ear and the auditory nerve – essentially profoundly deaf, he has come quite a distance. The outer ear collects the vibrations which are amplified in the middle ear and are then transuded into nerve impulses by the inner ear. The nerve carries these impulses to the auditory centre of the brain for the individual to hear the sound.
It was after his first birthday that his parents figured that he could not hear at all. Investigations revealed the absence of the biological tools necessary to hear and it seemed as if there was nothing more to it, just then.
However, at one year and 11 months, Kaushik had a surgery that has not only helped him hear eventually, but also notched his name in medical history. Mohan Kameswaran, director, Madras ENT Research Foundation, says Kaushik is the youngest-known recipient of an Auditory Brainstem Implantation (ABI). ABI is a technique in which a small chip is placed in the brainstem to “restore hearing sensation.”
“In 99.9 per cent of the cases, children will have a cochlea and a nerve in place. The cochlea may be defective and we replace it with a cochlear implant to facilitate hearing. However, none of that would work for Kaushik,” he explains. So instead of stimulating the cochlea, they had to put in an electronic device into his brain stem so as to directly stimulate the area of the brain that is responsible for hearing. An external device that fits snugly behind his bold ear, is fitted with a microphone and a mini-processor, also powers it. The internal chip’s electrodes stimulate the brain to produce sound.
“Since he had none of the tools for hearing, we had to use something that would bypass all this and target the auditory centre of his brain directly. Thankfully, hearing is among the most-organised activities of the brain and it is simple enough to be simulated with an ABI. In an ideal world, the ABI would ensure that there is no deaf person at all – it is the technology that will give hearing to everybody,” Dr. Kameswaran said.
A team of neurosurgeons from the Voluntary Health Services and ABI experts from the University of Wurzburg in Germany aided the ENT surgeons at MERF to put in the device made by an Australian company, costing just over Rs.10 lakh.
On Republic Day 2009, Kaushik got his own chip, with its 12 electrodes, implanted in the brain stem. When tested on the table, it seemed to work. But it would take at least three months before the brain could get used to the chip and it could be switched on. At his first perception of sound, the child cried, and his doctors were overjoyed. The device was working well and it was only a matter of time, with the appropriate auditory training, that he would begin to hear and speak normally.
“He has been training for the last nine months and his speech now is typical of a nine month old baby. He is sure to get better with time and training.” While the chip is for life, the external device comes with a warranty and can be replaced if the technology gets better.