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more photosImplant devices for hard of hearing
Cochlear implants aid hearing impaired when other methods fail
By Markian Hawryluk / The Bulletin
Published: March 04. 2010 4:00AM PSTDon Nachtwey's family began complaining about his hearing about 12 years ago. After accepting he had a hearing problem, Nachtwey steadily went through stronger and stronger hearing aids but his hearing kept getting worse and worse. Eventually his audiologist told him there was nothing more he could do for him; there weren't any hearing aids powerful enough to help him hear.
Then at a hearing loss seminar in Salem, Nachtwey attended a presentation about cochlear implants, a surgically implanted device with an external processor that turns sounds into electrical signals. Dr. Sean McMenomy from Oregon Health & Science University urged the audience members who thought they might benefit from an implant to go through the free testing process. Nachtwey had been told numerous times his hearing wasn't bad enough to qualify for a cochlear implant but went to get tested anyway.
“I flunked the test miserably,” the 76-year-old Bend resident said gleefully. “For the first time in my life, I was happy to flunk!”
He underwent surgery to have the device implanted and two weeks later, on Nov. 29, 2006, an audiologist at OHSU connected his implant to a processor and Nachtwey could hear again.
“From the moment she turned it on, I could understand words that I hadn't heard in years,” he said. “I can hear music. I can understand words that I couldn't hear before. I can talk on the telephone. I couldn't do that before. I wouldn't even pick up the phone.”
Across the country, thousands of Americans with cochlear implants are hearing for the first time in years or for the first time ever, sounds that most of us take for granted. And as the technology continues to improve, it's broadened the potential pool of people who stand to benefit from the devices. Yet many individuals and their doctors aren't aware of the new guidelines for cochlear implants. And that means many people who could benefit continue to live their lives in silence.
Getting better
Cochlear implants were approved for marketing in the U.S. in 1985. But early iterations of the device provided only limited benefit, making them useful only for those with complete hearing loss. When the Food and Drug Administration approved the devices, the agency also put in place standards for who stood to benefit from the implants. Patients are tested to see what percentage of a list of sentences they can understand while wearing a hearing aid but without the help of reading lips.
“Previously, the best a patient would expect was perhaps 12 percent sentence recognition performance with an implant. Therefore, the prerequisite was zero percent sentence recognition,” Steven Huart, an audiologist with implant manufacturer Cochlear Americas, explained in a physician education article for the Web site AudiologyOnline .com. “Now that the mean performance on clinical trials has improved to 90 percent open-set sentence recognition scores in quiet, those who only get 60 percent or less with hearing aids can consider cochlear implants a viable option.”
Meanwhile, insurance companies have improved their coverage for implants, making them more affordable for the insured. According to OHSU materials, the cost of an implant, the surgery and follow-up in the first year totals $40,000.
Almost all private insurers cover the technology. In 2005, Medicare lowered its threshold for coverage to those individuals who could understand no more than 50 percent in sentence recognition tests in the ear to be implanted and no more than 60 percent in the other ear. That opened the door for many seniors to qualify for the device.
Coverage still requires that patients try a hearing aid first. If a hearing aid works — and hearing aid technology also continues to improve — it's not worth going through a surgery. And sound quality with an implant could be worse than with a hearing aid for some people. Since cochlear implants destroy any vestiges of normal hearing in the ear, doctors won't operate if a person can get good results from a hearing aid. Once the device is implanted, hearing aids will no longer work.
Inner workings
The implants work differently than hearing aids as well. A hearing aid simply amplifies sound, relying on the remnants of a person's normal hearing to pick up vibrations in the air and convert them into electrical signals that the brain recognizes as sound. A cochlear implant relies on the external processor to convert sound waves into electrical signals. The electrical signals are then decoded by the electrodes implanted inside the ear and passed on to the auditory nerve.
“Most often, people will lose their hearing in the higher frequencies. If those portions of the auditory nerve have not been stimulated for five, 10, 20 or more years, and we start stimulating that, that's going to be pretty sensitive,” said Don Plapinger, chief audiologist at OHSU. “So what we have to do is regulate not only how much current is being sent to the auditory nerve but where that current is being sent.”
After implantation, the patient usually waits 2 to 6 weeks to heal completely and then the processor is connected and turned on. Over the next month, the audiologists work to refine the processor's programming to improve hearing.
“It takes a while to build up a good program,” he said. “People will describe speech as sounding like the Munchkins from ‘The Wizard of Oz' or Donald Duck, or ‘Why does everybody sound like a female?'”
Over time, however, as the program improves and the brain adapts, speech sounds more normal. Lois Johnson, president of the Bend chapter of the Hearing Loss Association, was first tested for an implant in 1990 but didn't qualify. By 2002, as her hearing worsened and the technology improved, she met the threshold.
“I could hear immediately,” Johnson said. “The sound was like Donald Duck talking underwater, but I could understand speech and could hear the letter S for the first time in 30 years.”
Over the next few weeks, she worked to train her brain to the new input. She had someone read to her facing away from her, and then she would repeat the words she heard.
“The best way for me was getting an audio book from the library and reading the printed book at the same time,” she said. “That way, the brain associates the words with the sounds. I read three books this way. The sound normalizes over a few weeks and the Donald Duck sound goes away.”
Five weeks after receiving her implant, she scored 100 percent on the sentence recognition test in a quiet room, and missed only three words in a room with background noise. She has now upgraded her processor for the third time, further improving her hearing.
“I can listen to oldies and pick out what the actual words are in a large percentage of the songs,” she said.
Incomplete solution
Plapinger said many people who have lost their hearing find that music just doesn't sound the same with the implants.
“Music is one of the things that really suffers,” he said. “People with cochlear implants can't tell the difference between the trumpet and the trombone.”
Plapinger explained that normal hearing relies on 25,000 to 30,000 hair cells in the cochlea while the implant has from 12 to 22 electrodes.
“You're asking 22 electrodes to do the same thing as 25,000 hair cells,” he said. “So you don't get the same specificity you get with normal hearing.”
But Plapinger said that young children who have been deaf all their lives and never heard music, don't have a frame of reference for what they're hearing.
“For them, music sounds the way they think it's supposed to sound,” he said.
According to Plapinger, OHSU does more than 100 cochlear implants a year, about 60 percent in adults and 40 percent in children.
The implants have been controversial in the deaf community. Some believe the implants to be a threat to the deaf culture. Many have complained that the implants have been promoted as a way to “fix a problem,” and many deaf individuals do not feel they need to be “fixed.”
In many ways, children are better candidates for the implants. Studies show one of the factors influencing the quality of sound is how long an individual has gone without hearing.
“You have young kids who are getting this implant, their brain is growing and you've got these strong neural pathways,” said Cory Richards, an audiologist with Central Oregon Ear, Nose & Throat. “If you can get to them early, they're going to do better than someone who is basically deaf for 30 to 40 years.”
Richards, who did a rotation with the OHSU cochlear implant clinic and worked with implant patients in Spokane, Wash., before coming to Bend, said he's seen profound changes in kids who receive implants. Children who couldn't hear unless the volume was up at 90 to 100 decibels — about as loud as a snowmobile — could hear at decibels of 25, slightly louder than a whisper, with the implants.
“It's pretty phenomenal technology,” he said.
Patients interested in implants generally start with a hearing test at an ear, nose and throat practice. But Richards said patients need to be realistic in their expectations. It's not a cure for deafness nor is it the best solution for every individual. Even people who meet the medical criteria for an implant wind up with a broad range of possible outcomes.
“It's about as wide as it can be,” Plapinger said. “Unfortunately, we have some people who get an implant and barely have speech recognition, all the way up to people who can use the phone. It's really difficult to predict who is going to do well with their implant and who is not.”
It's one of the reasons why pre-implantation testing is so rigorous. Doctors don't want to eliminate adequate hearing without a virtual guarantee of improvement. But Plapinger said the current standards help ensure that patients will not wind up worse off after the implant.
While the implants have been around since the mid-'80s, nobody knows for sure how long they will last. Some patients find their implants stop working over time and must have the implant removed and replaced with a newer model. Plapinger said the clinic is not replacing working implants simply because of improvements in technology. But like Johnson, patients can upgrade processors as long as they stay within the same brand.
There are three cochlear implant companies with products approved in the U.S. Plapinger said patients can choose among the three based on personal preference, but the choice will not affect the quality of their hearing.
“The companies would like you to think theirs is better,” he said. “But we tell our patients that all the devices basically do the same thing, they just do it a little bit differently.”
A better life
Many patients, especially children, are now getting an implant in each ear, which helps to refine hearing and has been shown to improve quality of life. Oregon is the only state that prohibits an insurance company from denying a second implant solely on the basis that a patient already has one. Patients can also make use of directional microphones that help them hear a one-on-one conversation in a noisy surrounding, or can plug processors directly into their phones.
It's provided new hope for many individuals whose hearing loss has affected the way they live.
“People who lose their hearing tend to withdraw from social situations and become depressed because they cannot participate with other people,” Johnson said. “The implant, or even just a hearing aid, can change that.”
Yet, a survey of cochlear implant recipients found that patients went an average of 12 years after the onset of profound hearing loss before getting an implant. But once patients learned of the implants, most were implanted within a year.
The American Speech-Language-Hearing Association estimates there are up to 1 million potential implant candidates in the U.S., yet only about 60,000 have been implanted so far. And studies show that quality of life for both children and adults with cochlear implants is equal to normal-hearing peers.
“One of the things I was asked when we were trying to decide about these things was ‘Are you going to feel uncomfortable wearing this on your head?'” Nachtwey said. “I said, ‘Everybody is wearing something on their ears these days; they're not even going to know the difference.'”
But he's also found that people notice the device and ask him about it. He's explained how it works to people with normal hearing, and has mentored people considering an implant themselves about the potential benefits.
“I can work out in the yard and I can hear the birds again,” Nachtwey said. “ I can walk along the stream and I can hear water running. It's just everything, my whole quality of life has improved.”
It's a day-and-night difference from where his life was headed before the implant.
“It was terrible,” he said. “I couldn't understand what people were saying. In normal conversation I was answering questions that weren't asked because I misunderstood what people were saying. At times it was rather hilarious.”
But it stopped being funny when his son wouldn't let him take care of his three-year old grandson anymore.
“We spent a lot of time around the ocean and my son said, ‘If Dad can't hear him, I can't trust him,'” Nachtwey recalled. “It was very hard to take but at the same time, I'm glad it happened because it finally pushed me over the edge. I finally went out and did something.”
Markian Hawryluk can be reached at 541-617-7814 or mhawryluk@bendbulletin.com.
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