Cochlear implants provide deaf people a bridge into the speaking world, but researchers are striving to make the devices do even more
April 27, 2007
To the casual observer, two women chatting about college life hardly qualifies as a miracle. Except that both are deaf and neither is using sign language. Look closer and you'll see that Nanci Linke-Ellis and Elizabeth Yazbek each wear a coin-sized device behind one ear. The crescent-shaped piece of plastic could be mistaken for a hands-free cell phone or MP3 ear bud. But this sound machine does much more.
Functioning as a translator of sorts, the cochlear implant both women wear helps them converse in a way that, to an outsider, looks like two hearing people talking. The device, parts of which are embedded under the skin, distills the ebb and flow of their voices into electric signals. These pulses then bypass the lifeless areas of their inner ear and stimulate the hearing nerves that still function, which in turn feed the sound signals to the brain.
Once in the brain, these pulses are somehow reassembled -- scientists aren't quite sure just how -- into something akin to speech, though a person with normal hearing wouldn't recognize it. The device performs this intricate electronic relay in real time, and its key component, the speech-processing computer in the earpiece, weighs less than an ounce.
For Linke-Ellis, an Ohio University alumna, the inner workings of this electronic marvel are overshadowed by what it enables her to do. With her implant, she can hear her husband talk and even pick up dialog from a movie. A 1971 graduate with a bachelor's in fine arts, she heads a nonprofit organization called InSight Cinema that helps bring the big-screen experience to moviegoers with hearing challenges.
She is visiting her alma mater on this spring afternoon to urge students of hearing, speech and language science to champion the rights of their future patients. With an almost evangelistic zeal, she describes to Yazbek and the other students the challenges she had to overcome as a deaf student at the university in the late '60s. It meant hustling to the front of classes to lip-read lectures; relying on friends to jostle her awake in time for classes, since an alarm clock or telephone would not wake her.
Linke-Ellis made it through those years and forged a successful career as an executive in the television and motion picture industries. She succeeded through "bluff and barter," masking her deafness and relying on her prodigious lip-reading skills. She would type up a co-worker's notes, say, if they'd agree to make a phone call for her.
"There were no [support] groups," Linke-Ellis said. "There were no resources to help people with advocacy. … I grew up without Disney."
The social landscape has changed since then, with passage of the Americans with Disabilities Act of 1990 and the growth of advocacy groups for people with physical challenges. At Ohio University, a group of students -- Yazbek among them -- formed the Sign Language Club in spring 2006 as a way of building a bridge between those who hear and those who can't.
Even more dramatic changes have come on the technological front, in the rapidly ad¬vancing field of cochlear implantation. During Linke-Ellis' college days, there were no implants. When they began appearing in the early '80s, the relatively primitive devices were little more than bulky curiosities that could detect a few sounds and assist with lip-read¬ing. Today, the sleek, behind-the-ear models worn by Linke-Ellis and Yazbek enable them and many of the 70,000 other implant users to hold a phone conversation.
As the technology advances, the volume of implant-related research has also grown steadily -- much of it originating from Ohio University's School of Hearing, Speech and Language Sciences. More and more, studies show that cochlear implants can be pivotal in helping deaf people to acquire or retain speaking skills, especially young children. In the most successful cases, children fitted with implants before age 2 have developed language skills on par with their hearing peers.
Cochlear implants function differently than hearing aids, which merely amplify sound. Implants, prescribed only for profoundly deaf people, serve as a sort of hearing surrogate, re-interpreting sounds for the brain that normally would be transmitted by the delicate array of bones, membranes and hair cells of the inner ear.
Implants are also far more expensive than hearing aids. The cost of evaluation, surgery, the device itself and rehabilitation can reach $75,000. Yet the devices have made the leap from novel technology to mainstream medicine, as most insurance companies now routinely cover the procedure, provided that a patient's hearing falls below certain performance levels.
Linke-Ellis was fitted with hers in 1993, soon after she lost the last trace of her hearing. To ensure maximum success with an implant, a patient with some hearing must receive the device soon after a total hearing loss, before the brain and auditory nerves "forget" what to do with sound.
"For me, [the cochlear implant] was life-altering because it allowed me to do things I'd never been able to do before," she said.
This article originally appeared in the winter 2007 edition of Atrium.