Written for Skoda’s “The Mind Behind” series for BBC Culture
One in 20 people live with disabling hearing loss or deafness. For the rest of us, it can be difficult to understand how a lack of hearing affects people’s daily lives.
As a young boy, Dr Graeme Clark AC (Companion of the Order of Australia) developed an acute awareness of the frustration and loneliness of hearing loss by watching his deaf father, Colin, a pharmacist in Camden NSW, struggling to connect with his family and the world around him.
At the age of five, Dr Clark told a school teacher he was going to fix people’s ears when he grew up. But no one would have guessed this childhood ambition would lead to one of the most revolutionary achievements in medical engineering: the cochlear implant, or “bionic ear”.
After achieving impressive results in high school, Dr Clark decided to study medicine, along with the new field of electrical engineering. His goal at that stage was to become an ear doctor in a major Australian town.
After training in Edinburgh, London and Bristol, and becoming a fellow of two royal colleges, Dr Clark returned to Australia as a ship’s surgeon and received an offer to enter private practice in Melbourne as an ear, nose and throat surgeon. This became routine, however, and despite his colleagues’ advice he was far too old, he decided to return to research at the ripe old age of 30.
“I still had a fire in the belly to do research, particularly to help deaf people like my father. For this reason I left Melbourne as a senior surgeon for a position as a poor research student with little pay to study brain physiology.”
At this point Dr Clark began turning his attention to the seemingly impossible task of creating an electrical device that could stimulate auditory nerves inside the ears of deaf people, enabling them to understand speech.
“I believed it was important for deaf people to hear speech rather than environmental sounds for the simple reason that understanding speech is so vital to our wellbeing and mixing with other people,” Dr Clark says. “If that was achieved then it would be expected that hearing environmental sounds would also be achieved.”
I considered there might be a chance of helping people understand speech with more thorough research."
Sparking Sounds
The earliest experiment in electronically stimulated hearing is perhaps its most infamous. In 1799, the famed Italian physicist and chemist Alessandro Volta decided to test the effects of the first battery by running an electrical current through two metal rods inserted in his ears. Aside from the expected shock from this adventurous experiment, Volta described hearing a crackling noise “like boiling soup”.
Dr Clark was aware of more modern (and less barbaric) attempts to stimulate the ear with electricity and in the mid-1960s he serendipitously came across a scientific paper by American academic Blair Simmons that would spark his own unique inspiration. It contained an account of a profoundly deaf person receiving hearing sensations through electrical stimulation, but they were still unable to understand speech.
“In some ways, I could see where he had gone down some blind alleys and I also believed that he had opened the way up for me to study the whole question more thoroughly,” Dr Clark says. “I considered there might be a chance of helping people understand speech with more thorough research and realised this could be possible with multiple electrodes or multi-stimulation to reproduce the frequencies in speech.”
“Thorough” may be understating the level of work required by Dr Clark and his team to begin developing the cochlear implant. Aside from the research itself, he found himself fighting tooth and nail for the vital funding needed to keep the project afloat, while also contending with countless sceptics within the medical community.
The bionic ear is still a revolutionary concept today, and in the early 1970s it wasn’t far from science fiction. At the time, genetic engineering and restoration of the body senses were the two major frontiers in medicine, so Dr Clark’s work was at the precipice of what was known about how we experience our world.
Nearly 40 years later, an estimated 350,000 cochlear implants have been successfully implanted worldwide, returning the power of communication and connection to countless families around the globe."
The sound of the ocean
For the cochlear implant to deliver on its promise, the project required equal measures of perseverance and imagination, the latter of which was demonstrated in one of the major breakthroughs Dr Clark experienced while on a family holiday at the beach. Among the many difficulties in such an ambitious project, a significant hurdle had been the need to get the electrodes through the intricacies of the ear to the auditory nerve.
“I wasn’t sure how to get the bundle around the tiny spiral of the inner ear to lie close to the nerve fibres for different frequencies. The breakthrough came through finding a seashell and seeing grass blades could pass around the tightening spiral if they were flexible at the tip and stiffer at the base.”
The biggest triumph, however, arrived during the first cochlear implant surgery in 1978. Dr Clark and his team made the discovery that stimulating different electrode places in their first patient’s inner ear would provide not only pitch quality but vowels as well.
“We were able to relate the vowels to particular resonant frequencies in speech and that gave the clue to pre-process the speech to get it through a neural bottleneck to the brain for it to be understood. I was so overcome I went in to the next-door lab and burst into tears of joy.”
Nearly 40 years later, an estimated 350,000 cochlear implants have been successfully implanted worldwide, returning the power of communication and connection to countless families around the globe. While Dr Clark says he finds joy in communicating with every patient – he’ll never forget the feeling of helping his first two patients to hear speech after they were robbed of the ability through illness and accident.
“The second patient had heard speech 13 years prior to his implant and he heard speech quite clearly at his second test session. It was exciting to realise the consciousness of speech could lie dormant in the brain for such a long time. It also raises the question of what is underlying speech in our own consciousnesses.”
After dedicating his life and career towards reconnecting patients’ internal world with the world around them, Dr Clark has also confirmed his belief in the innate power of speech to make those connections with the people we love.