I Can Hear You Whisper (10 page)

Read I Can Hear You Whisper Online

Authors: Lydia Denworth

BOOK: I Can Hear You Whisper
6.41Mb size Format: txt, pdf, ePub

“We will probably never know why this happened,” Dr. Dolitsky told me. “You could spend a lot of time and money trying to figure it out, but I don't think that's worth it.” Many cases of congenital hearing loss, meaning a loss present at birth, are thought to be hereditary, but that didn't seem likely in our case. Nonhereditary causes included infections during pregnancy. For example, an outbreak of rubella (German measles) in the 1960s affected many pregnant women and their fetuses and led to a higher incidence of deaf and hard-of-hearing babies, the so-called Rubella Bulge. Maternal diabetes, prematurity, toxemia, lack of oxygen, or complications with the Rh factor in blood could all cause hearing loss. Or a young child could have acquired hearing loss after birth from ear infections, meningitis, ototoxic drugs (medicine that damaged the auditory system), measles, encephalitis, chicken pox, mumps, flu, or head injury. Babies could even lose hearing from noise exposure, though that is far more common in adults.

There are, however, a few
causes of hearing loss that are linked to other medical issues. Those, said our doctor, are things you would want to know about. His recommendation was a medical workup that included only tests that were either easy (like a blood test) or that allowed us to rule out complications. I went home with a stack of prescriptions: EKG, ultrasound,
CT scan, and so forth.

First, we looked at genetics, which, now that medicine has succeeded in reducing infectious disease, accounts for about half of all hearing loss in newborns. In recent years, scientists have begun to isolate genes related to hearing loss. In three-quarters of inherited cases, the cause is an “autosomal recessive” gene called connexin 26, which can be passed on if each parent carries it. Alex's blood test was negative for connexin 26. Then we tested his heart, as there is evidence of a correlation between hearing loss and cardiovascular disease. Doctors don't yet know why that should be but hypothesize that the link might be impaired blood flow that damages the sensitive inner ear and can also damage the heart. Alex's EKG was normal. Next, we looked at his kidneys. Since both the ears and the kidneys form in utero around seven weeks, it's possible that if the fetus suffered some sort of trauma that affected the development of the ears, it might also have damaged the kidneys. Alex's kidneys were fine. Nonetheless, for a time, I replayed the seventh week of pregnancy in my head. We had been on a vacation in Italy with my extended family, a trip planned before I'd known I was pregnant. Because I was in Italy and because it was my third pregnancy, I allowed myself a few glasses of wine and some caffeine to battle the jet lag. Was that what did it? I knew better. There would be a far higher incidence of hearing loss in French and Italian babies if a glass of wine could cause it, but I wished I had never left Brooklyn.

The final test was a CT scan, which would give us a look at the inside of Alex's head. It required him to be completely still. Because that was an impossibility for a two-year-old, he had to be sedated again. Out came a big needle, and I held his hand. He whimpered but quickly fell asleep. Once he was asleep, the technicians laid him onto the scanner bed, and I moved to the control room, where I could watch through the window and see the computer screens.

The CT scanner consisted of an adult-size white bed that moved through a circular opening in a big white machine. It looked like a portal on a spaceship. CT stands for “computed tomography.”
Tomos
is Greek for “slice,” and that's what the machine captures: slices. It uses X-rays to make two-dimensional images of multiple layers of a three-dimensional object—in this case, Alex's skull. Together, those slices would be compiled to create a detailed picture of his anatomy.

There was my small son, dwarfed by the bed, his soft arms and legs peeking out of his orange shorts and blue-and-orange striped shirt, unconscious on the other side of the glass. Suddenly, overwhelmed by his vulnerability, I had to turn away and lean against the wall. Images were collecting on the screen, and the technician began to describe what he was doing.

“Uh-huh,” I managed to respond, my voice cracking a little. “Okay.”

When it was all done, I cradled Alex in my arms and carried him out of the hospital and into the sunlight of a bright June day, unwilling to let go.

A few days later, the phone rang. It was Dr. Dolitsky. “We found it,” he said. The CT scan had revealed that Alex had a congenital deformity of the inner ear similar to something known as
Mondini dysplasia or Mondini deformity.
It was rare, affecting fewer than 200,000 people in the United States, and it meant that his cochlea had failed to form completely. It seemed unlikely, then, that he had ever had normal hearing, despite the early hearing test that said otherwise.

In addition, he had a second condition that often accompanies Mondini dysplasia: enlarged vestibular aqueduct
(EVA), also known as large vestibular aqueduct syndrome (LVAS). Vestibular aqueducts are circular bony canals that look like soda-can pull-top rings and sit just above the inner ear. They help us balance. In Alex and others with EVA, one or more of the vestibular aqueducts is larger than normal, meaning it's more than one millimeter in diameter, roughly the size of the head of a pin. That makes it susceptible to injury. A bump on the head or a change in pressure could result in a rupture in the sac of endolymphatic fluid that is attached to the aqueduct. When that happens, the fluid inside drips down onto the inner ear, with which it is not chemically compatible. The result is further damage to the hair cells of the inner ear. Nearly every child with EVA develops some hearing loss, and according to the National Institute on Deafness and Other Communication Disorders, 5 to 15 percent of children with sensorineural hearing loss have EVA.

“The usual recommendation is no contact sports,” Dr. Dolitsky told me over the phone, explaining that strategy as a way of eliminating one category of risk. “And nothing that would involve a big change in pressure.” He ran down the list: karate, soccer, football, scuba diving . . . I scribbled notes on the paper that was at hand, a bright blue-and-green pad for making grocery lists that seemed a bit too lighthearted for the occasion. “You will have to make your own decisions,” he said. “Unfortunately, in some instances, a drop can be caused by an airplane flight or even a big sneeze.”

We finished our conversation and I hung up, a little stunned. I was glad to have an explanation, but now the situation could change again at any moment.

The boys were playing nearby in the living room, and I turned in time to see Alex follow the lead of his big brothers and leap off the couch. All three then rolled around wrestling on the floor. Scuba diving was not going to be my problem.

8
T
HE
H
UB

M
y rental car bumped down a long dirt road flanked by fields of crops. I glanced at my scribbled instructions and kept to the right. In the distance, I finally spotted a tall, thin, elderly man standing in front of a one-story frame house, part of a small group of buildings at the end of the road. He waved as I pulled up in front of him.

“You found me,” he said with a smile.

“At last,” I answered.

I had been driving for hours to reach this small town in northwestern Oregon between Eugene and Portland, but that wasn't what I meant. Dr. William House had been on my mind for some time.

As a surgeon in Los Angeles in the late 1950s, House had been the first American to seize on the idea of electrically stimulating the ear. The device he ultimately created, which was marketed by 3M, became the first to win FDA approval in 1984. Adoring patients called him Dr. Bill and considered him a hero. Ear surgeons today describe him as a “creative genius.” “Without him, we might not have a cochlear implant,” says Dr. Marc Eisen, a Connecticut otolaryngologist who has written about the history of cochlear implants.

Yet House has also been
roundly criticized over the years. Early on, while he was developing his implant, he was practically shouted down at scientific meetings. Establishment researchers—most of them on the East Coast—thought his idea would never work. “
Otology needs a new surgery; this isn't it,” said Harold Schuknecht, Harvard Medical School professor and chief of otolaryngology at Massachusetts Eye and Ear Infirmary, at one conference.
“If I tell you that a lead balloon will not fly, and you go out and build a lead balloon and it does not fly, what have you learned?” demanded another prestigious scientist. Even if it did work, they didn't like the way House was going about it.

Nonetheless, House built a cochlear implant that worked—his lead balloon flew, for a time anyway. It has since been replaced by more sophisticated devices, a development he resented and resisted. When I brought up House's name with basic scientists rather than doctors, some dismissed him as a kook or a “crazy surgeon.” I wondered what the truth of it all was, and I wasn't sure House would want to talk to me.

Then one day my phone rang. The man on the other end was cheery and welcoming even if he sounded every one of his eighty-seven years.

“I got your letter,” he said. “I'd be happy to have you visit.”

 • • • 

The idea of using electricity to treat deafness would seem to require a futuristic faith in the possibilities of science, but it dates to the late 1700s. Electricity was a relatively new source of fascination then, and curious scientists everywhere were working to understand its principles. The Italian physician and physicist
Luigi Galvani kept an electrostatic machine in his laboratory. One day, just as the machine was generating sparks, an assistant happened to touch the sciatic nerve of a dissected frog with a scalpel. The frog's leg muscle twitched. Intrigued, Galvani set up a series of experiments and succeeded in making the frog's muscle twitch under a variety of conditions. He had discovered bioelectricity, the fact that our nerves use electricity to send signals, though he didn't quite understand what he was seeing. The force Galvani called “electric fluid” or “animal electricity” looked to him like an innate, unique form of energy. The 1791 publication of his finding stirred excitement for its potential in treating medical conditions.

Galvani's compatriot Alessandro Volta, a professor of physics at the University of Pavia, was paying close attention. Unlike most of their colleagues, Volta didn't believe in Galvani's “animal electricity” theory. Instead, Volta guessed it was contact between two dissimilar metals touching the frog's leg that caused the stimulation—the frog was simply a conductor. Galvani answered by inducing the same response with two pieces of the same metal. Back and forth the two scientists went, trading competing theories. The disagreement was cordial (it was Volta who coined the term “galvanism” in honor of his friend), but it was persistent and public. Today, we know Galvani was correct in recognizing that the electricity occurred naturally in the animal tissue, and Volta was right that this was not “animal electricity.”

In his efforts to develop his own theory, Volta experimented with metals alone. He stacked pairs of silver and zinc disks separated by brine-soaked pads. When he touched the top and bottom of the pile with a wire, an electric current flowed through the pile and along the wire. The contraption became known as the voltaic pile; Volta had invented the battery.

To explore the idea of using electricity medically, Volta applied his voltaic pile to the body. First, he made muscles contract. Then, connecting his battery to the optic nerve, he generated a flash of light when he touched any part of his face. Next he turned to hearing. Into his own ears he inserted two metal rods connected to a circuit of thirty or forty cells with about fifty volts of power. Electricity crackled through him, and he later described the boom he experienced:


I received a shock in the head and some moments after I began to hear a sound, or rather noise in the ears, which I cannot well define; it was kind of a crackling with shocks, as if some paste or tenacious matter had been boiling.”

The scientific world was intrigued yet cautious. Few were willing to repeat the experiment on themselves. The connection between electricity and hearing had been made—literally—but for the next century and a half, there was little progress.

Then in Paris, in the 1950s, electrical hearing became reality when “the impossible” was tried.
André Djourno was a neurophysiologist who studied medical applications of electricity at the Institut Prophylactique (today called l'Institut Arthur Vernes). Working with rabbits and guinea pigs, he was stimulating nerves by implanting induction coils. Charles Eyriès was the chief of the hospital's head and neck surgery department and an expert in facial nerve repair. In February 1957, a fifty-seven-year-old patient, Monsieur G., came to Eyriès in fairly bad shape. Surgery to remove two large cholesteatomas, a skin growth that pushes from the middle ear into the inner ear, had left the man deaf in both ears and with extensive facial nerve paralysis. Eyriès wanted to reanimate the facial nerve with a graft. A colleague proposed that perhaps the man's deafness could be addressed as well if Eyriès implanted one of Djourno's induction coils during the surgery. The patient, Eyriès wrote later, had “
expressed the desire that the impossible be tried in order to put an end, however imperfect, to his total deafness.” Since he would be undergoing surgery anyway, it was thought he had nothing to lose. For his part, Djourno was fascinated by the opportunity.

The facial graft repair (using fetal tissue) was a success, but Eyriès and Djourno found the cochlear nerve “significantly shredded.” They put the active electrode into the remaining stump of the nerve and placed the induction coil in the temporalis muscle. During the operation, they tested the device with a variety of stimuli: bursts of low-frequency current at a rate of fifteen to twenty pulses a minute, then low-frequency alternating current, and also words spoken into a microphone. From the start, Monsieur G. heard sounds. He could discriminate the loudness or softness of sounds but not their pitch. Speech was unintelligible. During extensive rehabilitation in the following months, increasingly complex signals were tried. Eventually, the man was able to tell the difference between low frequencies, which sounded to him like “burlap tearing,” and high frequencies (“silk ripping”). He could hear some environmental noises and a handful of words, but he never understood speech. Within a few months, the implant stopped working. Eyriès and Djourno found that the electrode in the muscle had broken; a second implant also failed. Eyriès washed his hands of the project. Djourno tried again with a different surgeon and a new patient, but the young woman was less enthusiastic and Djourno's funding ran out.

Eyriès and Djourno reported on their work in several French medical journals. It received little attention in other countries, although at least one researcher suggested to me that they deserve the credit for inventing the cochlear implant. Their successful surgery was, however, mentioned in a short article in an English-language publication that was seen by a patient in California. He clipped out the article and brought it to his otologist, who happened to be
Bill House.

“The light went on,” House told me as we sat in his small living room in Oregon. A few years earlier, he had moved up from California to live next door to his son, David. “See, we'd known that putting electricity near the ear you get a sound, put it across the eye and you get a flash of light. So the nervous system is very highly attuned to telling you what's happening. [The French report marked] the first time I realized a patient had a total loss of the cochlea and could still hear with electrical stimulation.”

How could it be possible to hear with a nonfunctioning cochlea? The cochlea is the hub, the O'Hare Airport, of normal hearing, where sound arrives, changes form, and travels out again.
When acoustic energy is naturally translated into electrical signals, it produces patterns of activity in the thirty thousand fibers of the auditory nerve that the brain ultimately interprets as sound. The more complex the sound, the more complex the pattern of activity. Hearing aids depend on the cochlea. They amplify sound and carry it through the ear to the brain, but only if enough functioning hair cells in the cochlea can transmit the sound to the auditory nerve. Most people with profound deafness have lost that capability. The big idea behind a cochlear implant is to fly direct, to bypass a damaged cochlea and deliver sound—in the form of an electrical signal—to the auditory nerve itself. “The inner ear is a pretty beautiful natural platform for stimulation in the sense that from very early childhood, it's in a stable adult size and form,” says auditory neuroscientist Michael Merzenich, who was instrumental in a later stage of cochlear implant development in the 1970s. “Several surgeons got at the idea that conceivably you could excite it and recover enough hearing to be useful.”

To do that would be like bolting a makeshift cochlea to the head and somehow extending its reach deep inside. A device that could replicate the work done by the inner ear and create electrical hearing instead of acoustic hearing would require three basic elements: a microphone to collect sound; a package of electronics that could process that sound into electrical signals (a “processor”); and an array of electrodes to conduct the signal to the auditory nerve. How best to build those pieces was anyone's guess. Some of it at least seemed achievable with time. Electronics could be engineered, for instance, and tolerable levels of stimulation for the tissues involved could be determined through animal studies. More difficult was the question of how to excite discrete groups of nerve fibers. Even if those technical problems were solved, and electrodes successfully and safely implanted, a basic science problem remained, to which no one in the 1960s had an answer: what signal to send.

The processor had to encode the sound it received into an electrical message the brain could understand; it had to send instructions, and no one knew what those instructions should say. They could, frankly, have been in Morse code—an idea some researchers considered, since dots and dashes would be straightforward to program and constituted a language people had proven they could learn. By comparison, capturing the nuance and complexity of spoken language in an artificial set of instructions was like leaping straight from the telegraph to the Internet era. It was such a daunting task that realistically, most scientists thought the best they could hope for was to make speechreading easier. “
The more a researcher knew about auditory neurophysiology or speech acoustics, the more confident he was that implants could not provide a high (or even useful) level of speech understanding,” wrote Michael Dorman and Blake Wilson in an account of some of the early research. The few who “imagined that you could just replace the signals in the ear in some magical way,” says Merzenich, didn't really know much about “how the complexities of sounds that would be meaningful, like the sound of oral speech, had to be represented across the nerve to the brain.”

No one was sure what, exactly, the brain needed to hear to distinguish between a dog barking and a baby crying, or to know to get out of the way when a car horn blows. They doubted it would ever be possible to make an implant that allowed a child to hear his mother say “I love you.” Before sound could fly direct to the auditory nerve, someone would have to reinvent the airplane.

Bill House aimed to try. In his first year of private practice in Los Angeles, House saw two families with two-year-old children they suspected were deaf. At the time, there was no test to uncover hearing loss at earlier ages. House found it painful to tell parents their children were deaf. “I felt I was presenting a very bleak outlook to these parents,” he said. “What I had to offer seemed very inadequate.” When he learned about the work of Djourno and Eyriès, he immediately saw the potential to do more and resolved to pick up where the French had left off. “I felt if there was anything we could do, we should.”

It was an attitude he learned from his father. House grew up on a five-acre ranch in Whittier, California, not far from Los Angeles. Although they kept a few cows and grew avocados, oranges, and lemons, all of which were the responsibility of Bill and his brothers, the family business was dentistry. His father, Milus, set up a private practice in an old barn. Milus House wasn't the kind of father who played ball with his boys or took them fishing, but he made a big impression when he talked about the satisfaction he gained from fixing serious dental problems that affected patients' emotional and physical well-being. “
I could feel the joy he had as he talked about ‘fixing mankind,'” wrote Bill House years later. “I knew then that I too wanted to be a ‘healer.'” After two years as a dentist in the Navy, House went to medical school to specialize in ear, nose, and throat surgery, then narrowed that down to ear surgery, or otology. In 1956, he joined his half-brother Howard, who was ten years older, in practice at what became known as the House Ear Institute, a leading West Coast center for otolaryngology then and now. (Today it's called the House Research Institute and is run by Howard's son and Bill's nephew, John House.)

Other books

Severed Threads by Kaylin McFarren
The Gods of War by Conn Iggulden
Glasshouse by Charles Stross
Mercy Burns by Keri Arthur
Manly Wade Wellman - Novel 1959 by The Dark Destroyers (v1.1)
Body Dump by Fred Rosen
The Warlock Wandering by Christopher Stasheff