If new research from Australia fulfills its early promise, the technology that allows the deaf to hear will soon be able to help people with spinal injuries. As reported in the Australian media in April, the extensions to bionic ear technology could bring movement and feeling to paraplegics and quadriplegics. Epileptics may also benefit from the developments.
Designed by Professor Graeme Clark in Australia, the bionic ear, or cochlear implant, was the first hearing aid that enabled profoundly deaf people to understand speech. Two decades ago it was surgically inserted in a child. Since then, more than 60,000 people around the world have benefited, and Australia holds 70 percent of the global market for the implants.
Although it does not restore normal hearing, the device works by electrically stimulating the hearing nerves in the inner ear, or cochlea, allowing people with hearing loss to understand speech and many other sounds. The researchers are investigating whether a similar process of nerve stimulation will help the spinal cord to heal.
On April 11 at the Australian Center for Medical Bionics and Hearing Science in Melbourne, Prime Minister John Howard attended an event that marked the 20th anniversary of the first cochlear implant. The Australian leader, who wears a normal hearing aid, praised Professor Clark’s achievements and announced new funding for his research.
The professor, who recently received an Honorary Fellowship from the Royal Society of Medicine in London, said new special federal funding will lead to the development of better bionic ears and enable scientists to find ways to fix damaged nerves in the human ear. “Smart plastics,” which will coax nerve cells to grow towards the bionic ear, are technologies that are already available, he said. “I believe we could make it (the implant) perform better in noisy situations, like classrooms, family meal times and parties, and even for listening to music.”
Collaborator, Professor Gordon Wallace of the Intelligent Polymer Research Institute at the University of Wollongong, said the new technology relies on an unusual plastic that can conduct electricity. It can also act as a host structure for the molecules that stimulate nerve re-growth, he said. Passing a small electric current through the plastic releases the molecules and helps to reverse the death and degeneration of hearing cells that occurs after prolonged deafness.
Some of the progress will depend on finding better speech processing software, and better electrodes, according to Professor Clark. These go inside the inner ear and interact with the nerve cells to send signals to the brain. He expects to see the first results of the extended technology within five years.
Sources: The Australian, The Bionic Ear Institute