By: Jean Johnson for Medtech1
“For centuries, people believed that only a miracle could restore hearing to the deaf,” writes Philipos C. Loizou, PhD, professor in the Department of Electrical Engineering at the University of Texas at Dallas, in his book Cochlear and Brainstem Implants.
|The following information on cochlear implants is adapted from the U.S. Food and Drug Administration:|
Cochlear implants do not make hearing normal.
To get the maximum benefit from a cochlear implant, a person will need individual training, such as speech training, lip reading training, and auditory training.
For young children who are in school, those with cochlear implants may still need
special accommodation in the classroom. Examples include preferential seating, a note taker, a quiet environment away from noisy intrusions, and a sign-language interpreter or cued speech interpreter.
Loizou explains that it has only been in the last half century that scientists have bypassed the damaged portions of the ear and worked on restoring hearing with direct electrical stimulation of the auditory nerve. As is so often the case in pioneering work, the first experiments were discouraging with patients saying that the speech they were able to hear was unintelligible. Researchers, however, persevered. According to Loizou, they “kept investigating different techniques for delivering electrical stimuli to the auditory nerve, and the auditory sensations elicited by electrical stimulation gradually came closer to sounding more like normal speech.”
Indeed, strides in the past 50 years have been impressive, and the truly miraculous news today is that “a prosthetic device, called a cochlear implant, can be implanted in the inner ear and can restore partial hearing to profoundly deaf people,” states Loizou.
In 1984, the U.S. Food and Drug Administration (FDA) first approved cochlear implants. Two decades later, the agency reports in 2005 data that almost 100,000 people worldwide, and 37,000 people in the United States – 22,000 adults and 15,000 children – have been fitted for the devices that can so dramatically restore hearing capabilities.
Thirty-two-year-old Jaki Scheckter, a South African who has lived in California off and on over the years, is now one of those adults, and so far he couldn’t be more pleased. “It always gets better everyday, little by little,” he wrote in an email message to Medtech1. “Recently we did a few tests to get a baseline on where I am in listening. One of the tests was 20 questions of general everyday things like ‘what is your favorite color’ or ‘where would you like to go for vacation.’ With my speech therapist, Sandra Alexander, on my right so that I wasn’t looking at her and reading her lips, I only got one question sort of correct the first time. Then three lessons later, I got 14 correct after about two or three repetitions and six more mostly correct with one or two words not sure. Not bad!”
The encouraging improvement was only the beginning, however, and Scheckter didn’t have to wait long for an even better test result. “A week later, we went over them again. I got all correct, with eleven questions only said once and the rest two times. And that is without me practicing or memorizing them.”
The Technology: Enabling Hearing Even In Noisy Environments
As the National Institute on Deafness and Other Communication Disorders (NIDCD), one of the National Institutes of Health, puts it: “A cochlear implant is a small, complex electronic device that can help to provide a sense of sound to a person who is profoundly deaf or severely hard-of-hearing.”
The organization explains that there are two parts to the device, one of which is surgically implanted under the skin behind the ear and a second external piece that is worn behind the ear as well. The system works quite differently from a hearing ear in that it bypasses the damaged ear and directly stimulates the auditory nerve. The NICCD is careful to note that a cochlear implant “does not restore normal hearing. Instead it can give a deaf person a useful representation of sounds in the environment and help him or her to understand speech.”
Boston Scientific hopes to ratchet up the level of devices currently on the market and announced the FDA approval of their Harmony HiResolution Bionic Ear System in late September of last year. The bionic ear delivers five to 10 times more band width, thereby increasing the hearing potential of the device.
“The Harmony System represents the next generation of cochlear implant technology,” president of Boston Scientific’s Neuromodulation Group, Jeff Greiner, told Boston BusinessNews.com. “With the new system, we are able to actively steer electrical currents with a high degree of accuracy, increasing the number of spectral bands from 16 to 120. We are attempting to guide precise pitch information into the cochlea by taking advantage of surviving neural populations to help increase the user’s ability to hear in noisy environments and to better appreciate the intricate sounds of music.”
Scheckter got his implants surgically placed in November 2005, a good year prior to development of the Harmony System, but he says that he is thrilled about the HiResolution Ear System from Boston Scientific’s Advanced Bionics that he has. “I was recently a volunteer for Advanced Bionics at the AG Bell Convention, and it was great fun working with that wonderful bunch of professionals dedicated to improving the lives of people with hearing loss.”
Join Medtech1 in the second part of our series on cochlear implants where we will discuss which candidates are best suited for cochlear implants and follow Jaki Scheckter’s story as he moves through his first year with bilateral implants...