Sunday, April 30, 2006

DubiousWords

Dubious Benefits: Cochlear Implants in Question

In the basement of a medical building in Baltimore, Maryland, neuroscientist David Ryugo is keeping 12 congenitally deaf cats happy. It’s costing him $70,000 a year. Meanwhile, 250 miles south in a lab at Duke University, electrical engineer Leslie Collins persists in the same mission she’s had for the past 20 years: to carry many frequencies within few wires. At the University of Iowa, chief of Head and Neck Surgery Bruce Gantz is teaching surgeons how to rescue hair cells in the inner ear. And across the world in Australia, Rob Shepherd serves as acting director at a facility that’s home to “Australia’s finest scientists and research staff.” These four scientists share one mission: to make cochlear implants better. Money, effort, and energy have funneled into this goal for years—a goal driven by a view rooted deeply in the medical field, and epitomized in a statement made in 1853 by Prosper Meniere:

“The deaf believe that they are our equals in all respects. We should be generous and not destroy that illusion. But whatever they believe, deafness is an infirmity and we should repair it whether the person who has is it is disturbed by it or not.”

Meniere, a leader at Paris’s school for deaf youth, believed as Ryugo, Collins, Gantz, and Shepherd do after him, that speech could and should be a deaf person’s primary mode of communication. This view is shared by surgeons, speech therapists, and often the parents of deaf children. These people stand behind cochlear implants; they may mold their careers out of them.

Meanwhile, critics like deaf spokesman Harlan Lane question cochlear implants. These devices, they say, make deafness seem like a disability, when in truth, as Lane asserts, deafness is a culture. In his book, The Mask of Benevolence, Lane counters that the only reason Prosper Meniere, and the doctors and scientists after him, called repairing deafness a duty was because of fear: physicians wanted to keep their hands in the ear. But they knew then, as now, that many deaf people were not frustrated by being deaf, nor did the deaf see not hearing as a problem. Rather, they had grown accustomed to it. They embraced and were fully functional in their deaf culture—a world not easily understood by the hearing and speaking people outside it, but nonetheless, a world defined by its own, organic language and by distinct habits and views found nowhere else. Deaf people “speak” with their hands, incorporating flowing and fast gestures and colorful facial expressions into every second of their conversation. They are intelligent, driven individuals, as evidenced by the number of students earning higher degrees at Gallaudet, America’s premier deaf university, in Washington, D.C. They can function in the world at large, holding jobs and raising familes.

By keeping their hands in the ear, then, and by advocating implants, Lane believes that physicians and scientists are threatening this deaf way of life, especially for deaf children with hearing parents who see implants as the norm. Cochlear implants may mean the end of deaf culture, Lane asserts. The New York Times Book Review called Lane’s attack on implants, The Mask of Benevolence, “a tightly reasoned… persuasive and gracefully angry book.” Gracefully angry was just what he was during our February interview when I phoned him in his Boston office. Amidst the thousands of dollars and brightest of minds being dedicated to cochlear implants though, I needed to determine exactly what might keep someone from advocating them, exactly how these devices threatened the deaf way of life, and whether cochlear implants and deaf culture could co-exist.

In Lane’s mind, deaf culture and cochlear implants cannot co-exist. Beyond simply threatening cultural deafness by diminshing the need to sign, implants pose certain physical risks. “Once a child undergoes implant surgery,” he said, “the child is an implant patient for life.” Unlike other medical devices, such as implantable lenses for vision correction, for example, which can be removed if the eye changes, cochlear implants are permanent. What’s more, they completely destroy the inner ear. The surgery to implant them ruins any residual hearing a patient might harbor, erasing hopes that he will ever again hear on his own. This is an indisputable, biological fact, one with which everyone would agree. It is why some parents are hesitant to implant apparently deaf infants; they have no idea how much hearing their child might retain, but with the implant—the “heroic medicine,” as Lane calls it—all potential to hear naturally, however small, is lost.

Other physical risks of surgery remain clear and present, too, as they would for any procedure. A slip of the physician’s hand in the sensitive middle ear region, where drilling persists, has occasionally caused paralysis of regions of the face. The vestibular nerve, part of the auditory nervous system, has also been hurt in surgery, leading to long-term disruption of the patients’ sense of balance. Another risk associated with implants has been meningitis, a potentially fatal infection of the fluid near the brain. In 2003, the New England Journal of Medicine reported that the incidence of this infection was 30 times higher in implanted children than in those without implants. The FDA and the Center for Disease Control linked this incidence of meningitis to positioners, the small rubber wedges that enabled surgeons to more carefully position the devices deep within the inner ear. These wedges often harbored infection-causing bacteria, but fortunately, positioner-bound implants were only manufactured by one company—Advanced Bionics—and the FDA banned surgeons from using these models in 2002.

But physical risks like nerve damage and menigitis are just the tip of the iceberg. Psychological troubles created by implants, critics say, are far worse. Critics point out an irony inherent to these devices: meant to permit hearing and speech, they may actually leave children languageless for years. That’s because parents who spend $40,000 for an implant want their deaf child to be like them—to not merely hear, but to speak, and this speaking does not include signing. Many parents who pay for implants don’t encourage their child to sign at all in fact, Lane argued, and may even scold them for attempting it. Thus, for a period in their young lives, these children cannot sign, nor are they yet adept at understanding speech with an implant. And because parents develop hopes that the implant will make their child “normal,” they don’t take time to learn sign language themselves either.

To get feedback from the implant-friendly side and balance my query, I spoke with Dr. Lauri Rush, director of the Mental Health Center at Gallaudet University, and mother of a three-year old deaf girl with cochlear implants. Dr. Rush could not have disagreed more with Lane’s arguments on langaugelessness. Her three-year old daughter, implanted just a year ago, can sign very well, which both Dr. Rush and her husband have encouraged, but her daughter also speaks, and signing is not taking away from her ability to excel at it. The Rushes have enrolled their child in speech therapy courses, where she works with a trained audiologist to improve her listening and speaking skills.

And rather than leaving the girl languageless, Dr. Rush said that implants are doing just the opposite for her child: “I wasn’t worried about my daughter growing up deaf because I know lots of successful deaf people here at Gallaudet,” she said, “but I was worried that she wouldn’t understand written language very well, which is a common problem for deaf people. And I wanted her to be able to read, and now with the implant, she can hear better and so she can read pretty well, too.” Rush said her daughter is reading up to 30 words at this point, an accomplishment for any three-year old.

Surgeons who perform implant surgeries advocate this route of training in spoken language, rather than sign language, for their patients. Lane says this is a problem because research shows that throughout schooling or life, the typical implanted child will rely on some form of sign language. And since developmental milestones exist for signing, just as they do for spoken language, a child prevented by parents from practicing it will never master it. He will not master it, either, if he practices it too late, which occurs when parents wait to permit sign language until they find that their child is making little progress with an implant.

This delayed opportunity to master a language—whether signed or spoken—could, Lane argues, prevent a child from fluently exchanging messages with and learning about the world around him. It could delay the normal growth of the child’s intellect, in other words. Implant critics would say this occurs too often in implanted children, for neither their implants nor their hands permit full communication, and they are forced to straddle two languages ineffectively. Lauri Rush’s experience shows that this doesn’t have to be the case. She has shown that a child can effectively communicate with both sign language and cochlear implants and that having her daughter sign has not taken away from the child’s ability to be successful with her implant.

Rush’s willingness to learn sign language as a parent and to encourage it for her implanted daughter is unique, Lane says. It is not to be expected in a family that commits time, emotion, and money to the implant process. This conflict of interest is not apparent in families where both the child and parents are deaf, however, and so rarely do “deaf of deaf” children experience a delay in language mastery; even if they do undergo implant surgery, their deaf parents encourage them to sign from an early age, arming them with language from the get-go. And now, according to Rush, three “deaf of deaf” students have been implanted at the deaf elementary school near Gallaudet University. These students’ deaf parents chose to implant their children, just as Rush, a hearing mother, chooses to sign with her daughter. Implants for “deaf of deaf” are a rare occurrence, and this step reflects the beginning of an acceptance of cochlear implants in the deaf community.

Critics like Lane still worry. They feel that cochlear implants impinge upon identity. “A partially successful implant,” he explained, “may be worse [for a child’s identity] than none at all.” Implants, he says, can deny deaf children a clear sense of self. Once a child undergoes surgery, his ability to develop as a deaf person is hindered by the family’s commitment to the implant process—the intensive training for speech and hearing, the auditory benefit the implant provides, its visual appearance, and by the possible delay in acquiring sign language.

That the child will be able to develop as a hearing person either, though, is unlikely. Deaf children—even those with implants—are different from hearing children; though they gain hearing, many never lose their connection to the deaf world, or their inclination to sign. They typically grow up in schools with other deaf children, all of whom have habits—gestures, facial expressions, tendencies to touch—unlike those of hearing people. And when deaf people with implants go to get jobs, employers are often hesitant to consider them; though their hearing might be reasonable or even good, the implanted deaf still can’t always speak perfectly. An employer given the chance to hire either a hearing person or a deaf person with implants would likely choose the former, if for no other reason than his fear of the unknown, even if both were equally qualified.

Thus, a deaf person with implants will feel alienation from his new group, the hearing world, since he will not always be fully accepted or comfortable there. Simultaneously, he will maintain enough loyalty to his original group, the deaf community, that things said and done to discredit them will likely offend him. As such, an implanted child may slip between two potential sets of friends. “[He will] tend to be culturally homeless,” writes Dr. J. William Evans at the University of California Center on Psychosocial and Linguistic Aspects of Deafness, “belonging to neither the deaf nor the hearing communities.” Here again, Rush disagrees. Her daughter goes to school with deaf children who have implants, and with deaf children who do not. “They all play together,” she said. “And the older deaf students here at Gallaudet are becoming more accepting, too. I’ve heard them say that they realize their peers with implants still have difficulties. They still face problems hearing, despite the technology. They’re still deaf.” At Gallaudet at least, it seems that the deaf are realizing the limitations of cochlear implants and instead of categorizing their implanted peers as sell-outs, they are respecting their decision.

Lane says that psychological troubles associated with implants are faced not just by the children wearing them; some difficulties associated with cochlear implants are unique to the parents. An implant that does not live up to expectations may cause Mom and Dad to suffer a second cycle of regret and acceptance, just like the one suffered upon learning their child was deaf. Rush acknowledged experiencing a grieving period, which lasted several weeks, after her own daughter was identified—not diagnosed—as being deaf. But she has not grieved since because the implant has been a success. Stresses related to implants do sometimes mount as parents struggle to teach initial speech skills. While specialists initiate much of this teaching, the majority must progess at home. Rush did not deny this hurdle, but when she cannot understand her daughter’s speech, the two of them sign and communicate perfectly. Another stress Lane proposed might be the money involved in purchasing and maintaing an implant. Raising enough funds for the many medical and paramedical services an implanted child requires strains relationships, and while most third-party health insurance plans provide some benefits, a good part of the follow-up care and the training has to come from parents’ personal savings. “I’ve seen them hold raffles, sell ice cream, appeal to the generosity of neighbors and relatives,” said Lane. “Anything to get enough money to pay for this process.” But the process, Rush would say of her experience, has been completely worth the price.

Above all, though, Lane feels that hearing parents of deaf children with implants face obstacles on a social plane. Their plight is much like that of white couples who adopt a black child. Again, this wasn’t the case for Lauri Rush, who found little opposition from the deaf community when she asked various faculty and friends at Gallaudet how they felt about her decision to implant her daughter. “Only two people responded negatively,” she recalled.

Rush’s experience may not speak for the deaf world at large, but it provides hope that families who embrace implants can maintain respect for deaf culture, a respect which appeases the deaf, and that these families will perpetuate the deaf world’s strongest custom—sign language—despite taking a step associating them with the hearing world. Yet, Lane still believes that the option implants provide is an option that breeds intolerance. Parents who choose not to use implants for their children are often asked why they would deny their young ones the chance to hear, instead of being acknolwedged for the efforts to embrace deaf culture.

Truthfully, Lane was moderately convincing on the other end of the phone; his laundry list of explanations for why one might avoid an implant was, if not “tightly reasoned,” at least reasonable to me. Yet because Lauri Rush has so successfully fostered co-existence of implants and sign language under one roof, and because she has taken little heat from the deaf community for her decision, I won’t buy Lane’s accusations that cochlear implants disable deaf culture.

Furthermore, before Lane hung up, he gave me one more reason to doubt him, and this reason was science-based. He said that no evidence exists to date that implant surgery must be done within a certain time period in a young child’s life in order for the child to reap maximum benefits. Implanted early or late, at 1 year or 3, he said, the child will benefit the same; he won’t acquire language at a faster or more thorough rate, regardless, and he’ll probably rely on signing at some point anyway. In other words, implants could never be guaranteed to provide great hearing. Lane based this claim on the notion that scientists have not yet identified an exact critical period—or window of time in which cochlear implants must expose children’s developing brains to spoken-language input. Scholars have argued for years that such a period exists. Already, cochlear implants inserted at early and late stages of childhood are helping deaf youths to better hear language, so that they can speak and read it more clearly, but the arrival of an implant during such a specific window of time would likely ensure that the child receiving the implant could function—hearing and speaking—with little or no problem, meaning that the surgery, the training, the stress, the money, and all the other investments would provide a certain and strong return. But Lane was quick to point out that the scientific literature has failed to provide clear boundaries as to when such a hypothesized critical period might begin and end.

I didn’t tell Lane about David K. Ryugo and his research with congenitally deaf cats. I wonder how he might have responded, to know that in the basement of Traylor Hall at The Johns Hopkins Medical School, the critical period is, for the first time, beginning to be defined and understood.

Wednesday, April 26, 2006

BirthdayWords

-Enlightened You, on the Eve of your Birthday-

There’s a pulse that prevails now in evenings—
A pulse that’s so beautiful blue,
A pulse long as Niles and strong as the sea.
A pulse that reminds me of you.

You have in your mind eye’s a vision
To shape of your life something grand
And I know that you will. And I watch as you are
Becoming a brilliant-bold man.

I watch as you tackle cold science;
Equations and rigid-hard fact.
I observe how you, too, absorb Hegel,
No passion is there that you lack…

For you give your whole mind to your studies;
Initiative is what you take.
You rarely sojourn, but enlightened, press on;
Your will shall prove tricky to shake.

And I think, as a loving observer,
Who watches from Baltimore’s bay,
That you feel, my dear Mark, that you’re solo,
That parts of your climb will be gray.

But alone you are not in your efforts
To coalesce science and thought.
You stand beside strong men before you,
Who’s paths were not easily wrought.

You stand beside Plato and Caeser.
You sit next to leaders and kings.
And you rest beside men who aspired
To do, with their lives, noble things.

Tis true that their roads were brief thorny,
And maybe they, too, met loud fools,
But in their walks, pressing and forward,
Their minds became sharpest of tools.

Let the horns of your mind lead you onward.
I know you’ll achieve the unique;
Because that’s who you are, Mark— original.
I excitedly await your peak.

Happy Birthday!

.MGW.

Wednesday, April 19, 2006

IfWords

"If" by Rudyard Kipling

[an excerpt from my favorite poem]

If you can fill the unforgiving minute
With sixty seconds' worth of distance run,
Yours is the Earth and everything that's in it,
And--which is more--you'll be a Man, my son!

.MGW.

Monday, April 10, 2006

Thesis Words

Woo! April 10th, 2006, and the Master's thesis is done! It's about 40+ pages-- a bit too long to blog, but feel free to inquire within if you might like to read some/all. Here's the lay of the land, as far as sections:

· Dubious Benefits: Cochlear Implants in Question
· Defining the Critical Period: Cochlear Implants Restore Auditory Nerve
· From Impulse to Instrument: How Cochlear Implants Came to Be
· Fine Tuning: Improving Music by Adding Pitch
· Hybrid Implants: Better Hearing on the Horizon
· Twice As Good: Bilateral Implants for Adrean Mangiardi
· BAHA in Baltimore: How John Niparko Inserts Bone Anchored Hearing Aids


I owe many thanks to Hopkins neuroscientist David K. Ryugo. I surely would not have always known quite where to turn without him!



.MGW.

Sunday, April 09, 2006

YoroParkWords





Opened in October 1995, the Site of Reversible Destiny - Yoro Park - is an "experience park" conceived on the theme of encountering the unexpected. Strange angles, steep slopes, bold images... Keeping your balance there may be a challenge. Keeping your mind engaged should prove everything but.

http://www.yoro-park.com/e/rev/

.MGW.

Thursday, April 06, 2006

HybridWords

--Hybrid Implants on the Horizon: Shorter Electrodes are Helping More Hear--

In a research lab in Iowa, otolaryngologist Bob Gantz is destroying the cochlea. His cochlea-crushing moves aren’t hindering hearing, however, but helping it. That’s because “the ear,” as Gantz explained “is a forgiving organ,” a fact which scientists too worried about ruining its inner microstructure have not previously understood. They fear that snaking electrodes of cochlear implants into the cochlea destroys whatever hair cells still live there, causing complete hearing loss. Gantz, on the other hand, has dared to poke short electrodes into the cochlear space, and he’s shown that he can obliterate its outermost parts without disturbing the function of the hair cells deeper within the ear. This insight has allowed the University of Iowa scientist to develop a promising new cochlear implant, called the hybrid implant, which combines short electrodes with a familiar device—the hearing aid. Gantz’s invention blends the best of bionics with acoustic hearing to benefit a unique population who could not be helped by implant or hearing aid alone: people with high frequency hearing loss.

Hearing loss depends directly upon the health of hair cells in the cochlea. These microscopic cells, housed along the snail-shaped inner ear, pick up vibrations and convert them into electrical impulses that the brain recognizes as sound. Hairs in the deepest part of the cochlea pick up low-frequency sounds, such as music. Hairs at the cochlea’s entrance pick up high-frequency sounds, including speech. People who are profoundly deaf, like those who wear cochlear implants, can hear neither high nor low-frequency sounds on their own because the majority of their hair cells are damaged.

But complete hearing loss, affecting all the hair cells, isn’t the only type. With age-related hearing problems, for example, or with hearing loss suffered by Iraqi soldiers exposed to relentless gun fire and bomb blasts, not all hearing wanes. Rather, these people tend to lose high-frequency hearing first, meaning their inner hair cells are still intact. While most vowels are in the low frequency range, most consonants are high frequency sound bites, and as such, get distorted or lost for such patients. As specific consonants disappear, individuals can no longer discriminate a “g” from a “t,” for example. And since consonants are the milestones of speech, breaking up words which would otherwise be streams of squishy vowels, people with high-frequency hearing loss have great difficulty with speech understanding. They lose more and more words, until they’re unable to make sense of entire sentences.

For this group, whose only problem is detecting high-frequency sounds, a regular implant is a problem. Its far-reaching electrodes destroy hair cells deep within the ear, eliminating any ability to hear low-frequency information naturally. And even though the implant does step in and provide low-frequency hearing, it is a shackle compared to the cochlea, which, lined with thousands of hair cells, does a far better job of allowing people to hear low-frequency tidbits like music or the pitches in voice that distinguish one speaker from another. Thus, preservation of normal hearing is often preferable to the rougher sound estimates of a surgical implant for patients with residual heairng. But so far, there’s been no way to address patients in this middle ground—to allow them to enjoy the richness of sound through the low cochlear zones that are still working, while compensating for the high-frequency dead zones. These people have had to trudge through life not with implants but with hearing aids, which don’t clarify sound, but simply amplify it. And hearing aids turn up the volume for all sounds, not just speech. “But you could use the hearing aid to make the sound as loud as you like,” Gantz explained “and if you filter those consonants out, the sound still doesn’t make sense as words.” This has made for a disgruntled population of hearing-impaired patients—those who get nervous and depressed at social funtions because they cannot make out words, especially amidst heavy background noise.

Now, Gantz has the solution: make the electrode shorter, so it substitutes only for the hearing that’s already lost. Pair the short implant with a regular hearing aid to amplify the remaining low-frequency hearing, and people with high-frequency hearing loss just might hear again more like they did years earlier.

This resolution seems simple. But the idea to use shorter electrodes to selectively help hearing would certainly not have evolved so soon had Gantz not been willing to take a chance. “Electrodes were seen as risky. Once you start pushing them into the first turn in the inner ear,” Gantz explained, “there is a tendency for these wires to ride right into the sensitive scala media (a fluid-filled sack within the cochlea), meaning you disrupt the hairs cells attached to it and lose all residual hearing.” But Gantz believed that with calculated intrusion, hair cells in the depths of the ear would forgive a little interference. His courgae to explore this notion—to pry and poke in the cochlea—was fueled by observations of the work of a man who had dared to do it with cats, continents away in Australia.

At the Bionic Ear Institute in Melbourne, Robert Shepherd had been testing the fortitude of hair cells since the early 90’s. “I came across Shepherd’s work in a literature search,” Gantz said. “Before I knew about it, I had the concept myself that you could damage some hair cells and the rest would be okay, but I knew I was going to have to do animal studies before I could take this to patients.” Gantz found that Shepherd had already done such studies—the first of their kind—in cats. The Australian’s work involved winding electrodes into the ears of hearing kittens, whose hair cells were fully in tact. “I contacted Shepherd,” Gantz said, “and he told me about the kitten study. Basically, where he put the electrodes, the hair cells were a little bit damaged, but when he went deeper into the cochlea, the hair cells were still okay.”

Shepherd’s promising results in animals were a springboard for Gantz’s eventual work in humans. The Iowa physcian used the Australian scientist’s data “to convince the FDA that there was a possibility we could actually do human studies.” Gantz’s efforts were especially important in light of changing candidacy for cochlear implantation. “Hearing specialists were and are continuing to implant not merely the profoundly deaf, but also deaf people with more and more residual hearing,” he said. “But as you implant these patients, you hurt their remaining low frequency hearing—their music perception, or their ability to distinguish voices.”

By targetting only high-frequency hearing then, Gantz was hoping to avoid this. Ideally, his efforts would help not just a select group of patients, like older folks or Iraqi soldiers with specific high-frequency hearing loss, but also cochlear implant candidates who retained some low-frequency hearing and could benefit by keeping it. “Residual ability to hear is often better than what the implant provides,” Gantz emphasized. In everyday life, problems associated with relying on implant-generated low-frequency hearing are manifest at parties, business meetings, large events, anywhere where more than one voice—differentiated by a slight change in a low-frequency pitch—is presented to a patient. “Patients with cochlear implants always complain that they can’t hear speech in noise,” Gantz said. That’s because the implant doesn’t provide them enough pitch options to distinguish one voice from the next. In a crowd of talkers, many voices may resonate at the same pitch, leaving implant users clueless and frustrated. Hopkins neuroscientist David Ryugo also frequently hears this complaint. “People with hearing problems in noisy places get pretty depressed,” he said. “They might just go sit alone at a table somewhere to get away from the noise or to have a one-on-one conversation.” The physician in Gantz wanted to use his shortened electrode to stop this, to help patients who were going to get implants anyway to keep the best of what they had—their residual ability to detect sound. The scientist in Gantz was ready to explore every possible means of cochlear manipulation to make this a reality. “It’s really a balancing act,” he said, “of where the implant is better versus trying to save the residual hearing.”

In the late 90’s, Gantz began experimenting with act of balancing. He tested with a short electrode which extended only 6millimeters into the cochlea, compared to the standard 24. Gantz’s first test group was a population of subjects with little residual hearing. “I think the 1st group of 6mm subjects had only 10-15% word understanding,” he recalled. By doing trials in these patients, whose hearing abilities were nearly as bad as the profoundly deaf who regularly received full-spectrum implants, Gantz reduced risk. If he were to destroy their residual hearing, they hadn’t started with much anyway. Furthermore, in case his patients did lose this low-frequency ability, which would require them to receive full-spectrum implants, Gantz’s team had prepared a special secondary back-up electrode that could be inserted at the standard distance of 24mm into the ear, right beside the shortened version. His bases were covered.

But Gantz didn’t have to use the back-up. His study was a success. “The most important thing that we learned using the 6mm device,” Gantz said excitedly, “was that we could keep the hair cells of the inner ear alive when we used a short electrode! We knew because we preserved our patients’ voice discrimination just the way it had been for them before their operation.” This was the first time that hair cell plasticity had been demonstrated in humans. “Unfortunately,” Gantz explained, “we did not publish our results since we were trying to get enough data to submit to a high impact journal like Science or Nature. Both publications thought this study was too focused and needed to go to a journal with a speciality.” So Gantz’s work did not see print until 2003. He did present the concept, however, at the 10th anniversary of the National Institute of Deafness in October of 1998.

So far, about 60 patients have received the hybrid implant, manufactured by Cochlear Corporation. About 10 have had it for more than a year. “The device is still in clinical trials but initial results have wowed us,” Gantz said. He’s referring to patients’ ability to understand words. “We have a special test for word understanding,” Gantz explained. “And it’s the most difficult test we can do. We test with words that are monosyllabic.” Gantz explained that when you hear a word in the context of a sentence, “you get a lot of info from the context and you could guess at the words you don’t hear.” But when you hear a monosyllabic word alone, not only is there no emphasis on one syallable or the other, but there’s no context. A patient who can understand such words demonstrates that the hybrid is truly clarifying consonants. And it appears that it is: a year after the surgery, hybrid implant recipients are understanding an average of 70 percent of the words in standard hearing tests—up from 25 percent before the operation when they may have relied soley on hearing aids.

And the combination of bionic and acoustic not only beats a hearing aid, but a regular implant, too, which permits patients to understand just 50% of the words thrown at them in a hearing test. Gantz said that it will be important for some full-spectrum implant wearers to make the transition to hybrids. “Right now,” Gantz said, “a lot of people with 10-15% residual hearing are getting regular implants. They’re going to lose significant low-frequency hearing that way.”

While hybrid implants have proven successful in trials, they’ve not yet been approved by the FDA. Meanwhile, Gantz continues to receive funding from Cochlear Corporation. The Australia-based implant manufacturer waits in the wings for Gantz’s device to be market-ready. “The hybrid implant is a potential cash cow,” Ryugo said of Cochlear’s willingness to get involved. And in Gantz’s lab, “we’re all wondering when the hybrid’s going to be released for general use,” he said. When it is, the Iowa physician’s next concern is that other surgeons will understand how to implant the device. “There are certain surgical strategies you need to make the hybrid work,” he emphasized. “You have to know the anatomy, to get the electrode in there without hurting the critical hair cells. This role may be limited to technical surgerons,” he said, “not general ENT [ear, nose, and throat] doctors. And we’ll need to have people practice this a lot in labs.” In a phone interview, Gantz joked that he wished he could use larger surfaces, like pig ears, or even those of elephants, to practice this difficult surgery.

Gantz emphasized other ways in which inserting a hybrid would be unlike surgery for a normal cochlear implant. Mostly, it comes down to the cochleostomy—or opening of the cochlea—which is considered the most important intracochlear surgery moment. “We do things a little differently at that stage than Niparko does, for example” Gantz said, referring to the surgical style of reknown cochlear implant specialist and Hopkins physician, John Niparko. Though Niparko’s surgery involves a longer electrode, it is still the same width as the electrode of the hybrid, “and so he makes a hole in the cochlea, just like we do, that is 5 millimeters in diameter,” Gantz explained. “But during the cochleostomy, I take extra precaution. I’m very careful not to penetrate into the cochlea.” Gantz uses a sharp, diamond burr and small hooks to open up the snail-shaped organ. “Then I slide the electrtode in gently, in a minute or two,” he said. Gantz explained that so far, trials reveal that surgeons who pay attention to these details are doing quite well.

Beyond surgery, Gantz is also concerned that audiologists will understand how to instruct people in adjusting to hearing with the hybrid, once it is firmly implanted. “At Iowa, we’ve been implanting these on a trial basis for seven years, so our audiologists know how to help patients. But we’ve got to think about how to train other people to explain how to use this device effectively because it’s not easy to use.” After receiving the implant, most patients are pretty excited. “They haven’t heard this well in a long time since they have been struggling so long with hearing aids,” Gantz explained, “and all of a sudden they just say, wow! This is great.” But there are a lot of variables that factor into continued success. “Audiologists have to have a lot of experience with the programming.” Gantz mandates that specialists train and remind his patients that their brains will have to adjust to decoding electronically generated sound. Many people require extensive training to reap full benefits, and some describe an echo effect for a few weeks, as if they were hearing from two different places, until they become accustomed to the hybrid. “It’s not like turning on a lightbulb,” Gantz reiterated. “It may take six months to a year for patients’s brains to register what’s going on.”

But the wait and the training are worthwhile. Several trial patients have had the implant for 4 years now, and Gantz reported that even after that period, they are not at a stagnant place in their adjustment, but are continuing to distinguish more and more words. “It’s really retraining the brain, adapting to this thing,” Gantz said. “It’s like a learning new foreign language.” And he continues to have ideas about how to make his hybrids better. Cutting out all the high-frequencies in the hearing aid, so that the implant alone can cover them, is one strategy. “But most audiologists,” he said, “why would they wanna do that?” It appears that for as much success as his hybrids are likely to have, they will likely face opposition, too.

In the end, hybrid implants work precisely because they don’t go the extra mile, or millimeter. Rather they are a “short” version of their full-spectrum ancestors, the original electrode, combined with the familiar hearing aid. They act on a distinct part of the cochlea and they leave the rest alone, and in doing so, they provide a service that neither an implant or hearing aid could render. Most importanlty for Gantz though, he says the patients who have received his hybrids are happy, and they are no longer avoiding social situations for fear they can’t converse.

.MGW.