Bionic Ears - The Next Generation
of Cochlear Implants
by Hazel Inglis
HearingCenterOnline.com Staff Writer
What are cochlear implants? How long have they been around? How do they work? Is this technology going anywhere? All great questions which deserve honest answers. In our never-ending quest to provide the public with information about hearing and hearing technology, we stumbled onto a short, yet interesting article entitled "Deaf babies to get bionic ears."*
Intrigued, a staff member from HearingCenterOnline.com contacted Mary McFarland from Epic Biosonics, the company filing for the patents on the new technology, to find out more. In a telephone conversation and follow-up email correspondence, McFarland gave us new insight into the next generation of bionic ears--the Epic Cochlear Implant. She also clarified a few rumours and misconceptions circulating about this technology.
Before going into a lot of detail about the future of bionic ears, we would like to take this opportunity to explore the past and to give you some background information on cochlear implants.
THE FIRST COCHLEAR IMPLANT
The first wearable single channel implants were implanted by Dr. William House, Dr. Blair Simmons and Dr. Robin Michelson during the 1970's. On August 1, 1978, Professor Graeme Clark and his team from the University Department at the Royal Victorian Eye & Ear Hospital in Australia implanted the very first 10-channel cochlear implant.
The procedure was performed on 48 year old Rod Saunders who lost his hearing eighteen months prior due to a head injury that damaged his cochlea. This successful operation was a major step in hearing technology. It provided a new opportunity for the profoundly deaf who could not benefit from standard hearing aids. Cochlear implants became commercially available during the early 1980's and in the past twenty years, they have improved in quality and sophistication.
A cochlear implant is an electronic device that bypasses damaged hair cells in the inner ear, and electronically stimulates the hearing nerve. This allows the profoundly deaf ear to perceive a simulation of sound.
It is important to remember that "hearing" varies immensely from person to person. Whether they have lost their hearing before acquiring speech or after will have a significant impact on their auditory memory or ability to recognize sounds. In addition, the number of channels or frequencies an individual hears with an implant will directly impact their recognition of sound and speech. For example, a person with normal hearing until their mid-twenties, that suddenly loses their hearing, will have much greater success with an implant than someone who loses their hearing before they are six months old.
Generally, the more channels in a cochlear implant, the higher the clarity perceived. Single channel implants would most likely only give recipients sound awareness. With an implant that has between one and four channels, a person may be able to tell the difference between a dog and a doorbell, or traffic noise versus the presence of speech. With a 10 to 16-channel implant the person would be able to detect even more words, but would have difficulty differentiating between words like cat and hat. With today's cochlear implants of 20 to 24 channels, speech should be a lot clearer to an individual. Nonetheless, even these devices would sound less natural than a normal ear with over thirty thousand hair cells.
According to the Bionic Ear Institute over 20,000 people (10,000 children) throughout the world now have cochlear implants.
THE NEXT GENERATION
Now, over twenty years after the first cochlear implant, a different group of scientists are well on the way to producing the next generation of the bionic ear.
We put a call into Mary McFarland, the Vice President of Administration at EPIC BIOSONICS in Victoria, British Columbia, Canada to tell us more.
EPIC BIOSONICS is the creator of a new type of cochlear implant, "The Epic". What makes it so unique compared to a regular cochlear implant is that it requires less time to implant, it is smaller and lighter; it has no external components; it's power source is designed to last a lifetime and it contains 48 versus 20-24 electrodes or channels.
The Epic Cochlear Implant will be fully implanted into the middle ear in a shorter surgical procedure than a conventional implant. In this minor operation, a microphone is implanted under the skin in the ear canal. This picks up sound and sends it to a speech-processing device which is similarly implanted under the skin behind the ear. The speech processor converts the sound into electrical signals. These signals are sent to an electrode array, which is implanted in the cochlea of the inner ear. Here they stimulate the remaining nerve cells responsible for hearing. Hearing occurs when the brain receives information from these nerve cells via the auditory nerve (the nerve which connects the cochlea to the brain).
The device is expected to weigh less than three grams and measure approximately 3 cm by 5 cm. This means that it is small enough to be implanted into a newborn baby, allowing the hearing part of the brain to be stimulated. According to McFarland, "This will facilitate speech and language development from an early age. The later a child is implanted, the more difficult it is for the brain to adapt to hearing stimuli, and the more difficult language and speech are for the child to develop." By being able to intervene early, a child stands a greater chanc of being able to learn speech as adeptly as her hearing peers.
As this "internal cochlear implant" will require no hard-wired external devices, no sockets, no wires, it will stand up to use 24 hours a day, seven days a week even in harsh environments, i.e. swimming. In contrast, cochlear implants on the market today have speech processors that must be worn on the body or behind the ear. These can be bulky, cumbersome and can't be used in many environments. The Epic will use less than a millionth of the power required by a light bulb. This is partly due to the fact the speech processing chip utilizes a new hybrid analog/digital technology which requires much less power than a totally digital device.
The device will use a miniature rechargeable battery that is designed to last a lifetime. The battery will require no more than 1-2 hours of recharging per week. According to McFarland the rumour that rubbing a bone behind the ear will recharge this device is completely false. Instead it will be recharged with an external battery that transmits the charge to the internal battery using radio frequency and no wires. This internal battery employs a new technology that does not involve a liquid electrolyte. Therefore, there is no risk of leakage.
The quality of sound in this device should be an improvement from conventional cochlear implants because of the configuration and placement of the electrode array in the cochlea. While existing cochlear implants have 16, 20 or 22 electrodes, the Epic Cochlear Implant has 48.
The Epic Cochlear Implant was originally conceived by ENT surgeon, Dr. Alan Lupin in 1988. He patented his idea in 1994. In 1997, Mr. Peter Berrang a Canadian businessman and scientist, joined with Dr. Lupin to form Epic Biosonics Inc.
Epic Biosonics, a Canadian company is in the research and development stage of this completely internal Cochlear Implant and has already begun the patent process. They have contracted a company out of the UK (Imperial College Innovations Ltd.) to supply the Micro-electronic speech processors. Dr. Chris Toumazou of the Imperial College of Science, Technology and Medicine developed the speech processing microchip in 1999.
Like other cochlear implants, this unit will be suitable only for those with severe-to-profound sensorineural hearing loss (nerve deafness), who would receive little or no benefit from hearing aids.
Epic Biosonics expects the first human implant to be performed by the end of 2001.
WE CAN REBUILD HIM...
Admittedly, I am a science fiction buff. I perceive science fiction, or perhaps more correctly, concepts from science fiction, as driving technology in the real world. Personal needs, imagination and willpower have always driven people to create extraordinary inventions that can make a difference to people like you and I. From traveling into space to computers that can talk, ideas once thought of as science fiction are continually becoming reality.
One of my favorite TV series when I was younger was the Six Million Dollar Man (aired in 1973). The main character, Steve Austin, played by Lee Majors, was a Colonel in the Air Force as well as a volunteer for NASA. He was chosen as a test pilot for an experimental aircraft but something went wrong in the final stages of the test and there was an accident.
In early episodes Steve Austin was portrayed as a man in complete rejection and denial of his situation; he couldn't come to terms with the fact that he had lost the sight in his left eye, and had his right arm and both legs amputated. When Steve is told that there is a chance that he can be fitted with new limbs, he is shocked. The Doctor explains these are very special and once fitted he would be able to hold a woman's hand and she wouldn't be able to tell that it was bionic. The skin texture, heat, and hairs would all match his own arm. The tremendous success of this television (and movie) series led to additional features starring the bionic woman, Jamie Sommers, played by Lindsay Wagner. Her bionic parts were the first to include a bionic ear.
The scientists and doctors behind cochlear implants have imagined and created this extraordinary piece of technology to fill an incredible need that most take for granted. They are making a difference! The dream behind a great invention like the cochlear implant, must wait for technology to "catch-up" in order to be fully realized. Technology, however, continues to make strides to match or surpass that vision. Although the bionic ear at present is not a substitute for a fully functional human ear, science and technology continue to advance, bringing the dream closer to the reality. Let's hope the Epic Cochlear Implant will prove to be the next landmark on the road to that dream.
*"Deaf babies to get bionic ears," posted on the newsgroup alt.support.hearing-loss on Feb. 24, 2000
Interview with Mary McFarland
VP of Epic Biosonics (March 2000
Advanced Bionics Corporation (2000).
Web site at http://www.cochlearimplant.com
Cochlear Ltd (1999-2000).
Web site at http://www.cochlear.com
Bionic Ear Institute (1999)
Web site at http://www.medoto.unimelb.edu.au
For Additional Information About Cochlear Implants Please Also See:
MED-EL Cochlear Implants
Web site at http://www.medel.com