Increasingly, Wired for Sound
New Technology, Guidelines Extend Reach of the ‘Bionic Solution’ to HearingLoss: Cochlear Implants
By Ranit Mishori
Special to The Washington Post
Tuesday, January 10, 2006………………..
One afternoon in 1999, Denise Portis’s son Christopher fell and hurt himself badly. But Portis didn’t answer his cries. The reason: She couldn’t hear him. Since age 27, she’d been living with a profound and progressive hearing loss, its cause unknown. She thought she’d adapted. Then the incident with Christopher “shook my world,” the Frederick woman recalls. She already was using two hearing aids, but she knew she needed something else. A while later, she got it: a cochlear implant — a needle-sized electrode surgically placed under the skin at the base of the skull, behind the ear.
Last July, several congressmen and guests of the Congressional Hearing Health Caucus watched a video of the results. As a technician switches on the device, amazement lights up Portis’s face. Then Christopher, now 14, said, “Hi, Mom.”Portis, 39, bursts into tears.
“The last time I really heard him clearly,” she recalled later, “he was in kindergarten and he still had a little-boy voice.”
Growing numbers of Americans appear to be joining Portis in opting for the”bionic solution” to hearing loss. Med-El, one of three leading implant manufacturers, estimates market growth at 15 to 20 percent a year. According to the Food and Drug Administration (FDA), approximately 13,000 adults and10,000 children had received implants as of 2002, the last year for which data are available. Several factors suggest growth could accelerate. In April the Center for Medicare and Medicaid Services expanded implant eligibility criteria. Some researchers are recommending “doubling up” — getting an implant in each ear — for better results.
Meanwhile, the devices are becoming smaller and more reliable, while implant surgery is growing faster and easier: It is now usually done in a few hours as an outpatient procedure. A hybrid device being evaluated by the FDA — a digital hearing aid coupled with a cochlear implant and speech processor — is designed for people with hearing loss too severe for effective use of hearing aids but too good for standard cochlear implants. Some experts predict that could double the number of people who would benefit from implantation. Implants are becoming almost trendy: Rush Limbaugh has one; so does formerMiss America Heather Whitestone McCallum. Hip-hop singer Foxy Brown, who recently disclosed her hearing loss, is considering joining the ranks of the cochlear implanted, too.
Some of the growth is attributable to the aging of the baby boom generation, some to improved newborn screening for hearing deficits. Even infants under 12 months can now benefit from implants, according to a recent article in Pediatrics. New evidence, reported this month in the journal Proceedings ofthe National Academy of Sciences, suggests that the earlier a hearing-impaired child receives a cochlear implant, the better. And the market appears ripe. A 2003 editorial in the New England Journal ofMedicine set the number of potential U.S. implant candidates at 1 million. An estimate by the National Institute on Deafness and Other CommunicationDisorders (NIDCD) puts the figure at seven times as many.
Unlike a hearing aid, a cochlear implant doesn’t just amplify sound. “It works totally differently,” said Richard Miyamoto, chairman of the Department of Otolaryngology –Head and Neck Surgery at the Indiana University School of Medicine and president-elect of the American Academy of Otolaryngology. In normal hearing, the outer ear collects sound (a car alarm, a child’s voice, a dog’s bark) and sends it into the middle ear. There, sound waves bounce off the eardrum, go through tiny bones and reach the inner ear, where fluid waves carry them to the cochlea — the snail-shaped organ that is the ear’s hearing center. Here, tiny “hair cells” convert sound waves’ vibrations into electrical impulses. The auditory nerve transmits those impulses to the brain, which interprets them and recognizes them as distinct sounds. Sensorineural hearing loss — the most common kind — occurs when hair cells are damaged or destroyed by infections, drugs and inflammatory conditions, among other causes. A cochlear implant, said Miyamoto, takes the place of a defective inner ear. By passing the damaged hair cells, the device detects sound waves and sends them as electric impulses to the brain.
By the time Denise Portis went for a cochlear implant evaluation at the Listening Center at Johns Hopkins Medical Center in Baltimore, she had little residual hearing left to amplify.
“I was born a hearing person, and [grew up] hearing all the wonderful things in the world around me,” she recalls, ” and I was no longer this person.” Over the years, she had learned to “fake it,” said her husband, Terry, who is executive director of the Bethesda-based Hearing Loss Association of America (formerly Self-Help for Hard of Hearing, or SHHH). She resorted to tricks like reading lips and interpreting speakers’ facial expressions. Terry would see “the nod, the smile, the ‘I-understand-what-you’re-saying’ expression ” used by many who lose their hearing, he said, “but they’re missing something.”
For Portis, too, faking worked only up to a point. Gradually, she dropped out of activities in her community, church and children’s school — feeling some of the isolation and depression that often accompanies hearing loss. She felt increasingly distanced from her family.
“Imagine only hearing parts of words and about 30 percent of a sentence,”she said. “I couldn’t go to a movie with my family and hear very much of it. I was unable to hear in church. I couldn’t go get ice cream with friends and talk about how exasperating teenagers were. I couldn’t listen to the radio or CD player. The doorbell, phone ringing and dryer buzzing were all sounds that I read about, but could no longer even place in my memory of how they sounded.”
As it happens, the decline in Portis’s hearing coincided with advances in hearing restoration. Since the first cochlear implant was approved by the FDA in 1984 and the first child’s version approved in 1990, the devices have evolved from analog to digital, from single electrode to multiple electrodes with improved speech-processing. New types also allow researchers to externally manipulate the “coding strategies” used to translate sound into the signals the implant sends to the cochlea.
Learning to Hear
Many with hearing loss assume they’re not implant candidates based on what they were told years ago. They don’t know that candidacy criteria have broadened, said Gail Whitelaw, president of the American Academy ofAudiology. Portis underwent a battery of tests to identify any reversible causes for hearing loss (such as certain infections, drugs and inflammatory conditions) or other conditions (for example, a damaged hearing nerve) that would rule out an implant. Absent such contraindications, said Terry Portis, a person is generally eligible for implantation if he/she can identify no more than 50 percent of key words in spoken sentences with a best-fit hearing aid in the poorer ear and 60 percent or fewer of the key words with such a hearing aid in the better ear.
In April, Portis was put under anesthesia for the nearly two-hour procedure. The total cost of the implant, including evaluation, surgery, the device and post-operative rehab, which is considered essential, was around $40,000. Her insurer, CareFirst BlueCross BlueShield, covered the surgery and follow-up care, but not the required pre-surgical psychological evaluation. Many health plans cover cochlear implants, although they often place limits on rehabilitation. The sound of her son’s voice wasn’t the only thing that changed for Portis. Implants change sounds in general — an important point for patients to understand. You will get hearing back, said Whitelaw, but probably not all of it, and not the way you remember it. Users will, in most cases, need to”learn” how to hear with the implant. No one can predict how well the device will work for any given person. “The question really is how hard the person will work to learn to use the device,” said Miyamoto. Rehab initially involves programming, or “mapping,” the device: Sound signals are sent to the implant user, who responds when he hears them. The audiologist adjusts the device to reflect the lowest level at which signals are detected. Audiologists and speech pathologists continue to work with the user long-term. Hearing generally improves with time and practice. In children, the process may be more involved, as many have to learn how to speak and produce intelligible sounds.
Portis speaks of getting her hearing back as being a kind of rebirth. “I have learned that our microwave beeps when you punch in a cooking time, and that my coffee maker gurgles and burps while making coffee. The sound of my dog’s pant is worth the doggie breath and if I leave my implant on while reading in bed, I’ve discovered my husband does still snore.”" I am hearing new things every day,” she said. “And, I wonder, when will Christmas be over for me?”
Ranit Mishori, a family practice resident at GeorgetownUniversity/Providence Hospital