The Wall Street Journal-20080216-Encore -A Special Report-- Sweet Sounds- After years of failures and frustrations- implanted hearing aids appear to be on the horizon
Return to: The_Wall_Street_Journal-20080216
Encore (A Special Report); Sweet Sounds: After years of failures and frustrations, implanted hearing aids appear to be on the horizon
Full Text (1465 words)Sherry Johnson's hearing aids were an annoyance.
Her ears sweated and caused a fungus to grow, which had to be treated with medicated cream. And every time Ms. Johnson, a Woodville, Miss., travel agent, went on a trip, she had to remember to take extra batteries.
So in October 2006, she became one of only a few dozen people in the U.S. to get an investigational hearing device, which is surgically implanted under her skin behind her right ear.
So far, with a scar hidden under her hairline and a battery expected to last years without recharging, "it's just like having normal hearing," says Ms. Johnson, age 72.
After years of failures, a small vanguard of companies, scientists and ear surgeons are making strides toward an ambitious goal: replacing traditional hearing aids with surgically implanted devices. But unlike cochlear implants, which are commonly used to treat profound deafness or severe hearing loss, so-called middle-ear implants, like Ms. Johnson's, have the potential to reach a larger group of people, including those with age-related hearing loss.
Two fully implantable devices -- made by Envoy Medical Corp. in St. Paul, Minn., and Otologics LLC of Boulder, Colo. -- are on the market in Europe and are entering final-stage tests in the U.S. A third manufacturer -- Med-El Corp. of Durham, N.C., a unit of Austria's Med- El GmbH -- already is selling its device, which is partially implanted in the body and has a small processor on the outside under the hair, in the U.S. and in Europe.
About 36.5 million Americans have hearing problems, according to the National Center for Health Statistics. But only about 20% of those who could benefit from a hearing aid actually use one, says Carole Rogin, executive director of the Hearing Industries Association, a trade group in Washington, D.C. Many people, she says, are "in denial" about their hearing loss or fear the stigma of wearing a hearing aid.
Makers of the implanted devices say their products will address both issues. "We have a generation that is going to be violently opposed to getting old," says Jose Bedoya, chief executive of Otologics. The new technology, he adds, will help "make their disability invisible to them."
Surgically implanted devices have several potential advantages. They are convenient; with the fully implantable devices, people can swim and shower without removing them. They satisfy vanity since they're invisible. For patients who can't wear conventional hearing aids due to infections or wax buildup, implants may be the only option. And some patients report better sound quality than regular hearing aids, particularly in the high-frequency range -- with less or none of the squeaky feedback sometimes associated with conventional hearing aids.
But the new devices also have major downsides. The surgery generally takes two to three hours or more, under general anesthetic, and leaves a scar and often a small bump on the skull. "There's something about surgery on the head. People freak out," says Brenda Battat, associate executive director of the Hearing Loss Association of America, a Bethesda, Md., nonprofit patient-advocacy and support group.
The surgery needed for the Envoy device, in particular, has raised eyebrows among some doctors because it involves removing a portion of the incus, a small bone in the middle ear. If the implant is removed, the incus will need to be reconstructed surgically and the patient may lose some hearing. "It's the old Hippocratic oath: Do no harm," says William Slattery, director of clinical research at the House Ear Institute in Los Angeles.
Patrick Spearman, co-chief executive of Envoy, says one patient who had the device removed had his incus successfully reconstructed using bone cement, with hearing slightly diminished compared with prior to the implant.
Then there's the price tag -- currently as much as $37,000 for one ear, including the surgery. Insurance coverage in the U.S. is scant so far, although some patients who were unable to wear conventional hearing aids have received reimbursement. Manufacturers say they expect costs to drop over time, but just how much remains to be seen.
Dr. Slattery says that because of the current high cost, he fears that "CEOs and actors [will] have the implants, and the working class will still have hearing aids."
Middle-ear implants work differently than traditional hearing aids. In normal hearing, sound causes the eardrum to vibrate, causing movement in three middle-ear bones, which is then translated into a signal picked up by the auditory nerve. Conventional hearing aids amplify sound and deliver the louder signal into the ear canal. Middle-ear implants work by transferring the signal directly to the middle-ear bones, causing them to vibrate.
"One of the principal advantages of implantable hearing aids is that they directly transfer the amplified signal into vibrational energy, which drives the ear," says Jonathan Spindel, a biomedical engineer at James Madison University in Harrisonburg, Va. "You've taken out the step that degrades the signal."
That's in theory. Actually getting there has been a challenge. Since the microphone is under the skin, the device must be specially adjusted to cancel out all the sounds of the body itself. Otologics, for example, found that the sound of skin rubbing over the microphone can cause feedback every time a patient moves his or her head, and the patient's voice reverberating through the skull cavity is also picked up.
Tweaking the adjustments on the device appears to minimize these problems. In a first clinical trial of patients published last year in the journal Otolaryngology, patients who received the Otologics Carina implant in only one ear performed slightly worse on hearing tests than with the conventional hearing aids they had used before the surgery.
But in the company's second, still unpublished clinical trial -- before which tweaks were made -- patients heard more clearly than people in the first trial as well as those with conventional hearing aids. Of the 10 people tested, two had to have the device removed because of a technical glitch that has since been corrected, says ear surgeon Drew Horlbeck, who headed the trial at Wilford Hall Medical Center in San Antonio. Of the other eight, most say the implant is "as good as a hearing aid, and a few of them feel it's better," says Dr. Horlbeck, who is currently working in Jacksonville, Fla.
One of the trial patients, 61-year-old Air Force veteran James Sauer of San Antonio, says his implant sounds realistic, "almost like normal hearing." But, as a retired drill sergeant, he tends to talk loudly, resulting in a crackling feedback. Engineers have adjusted his device twice, but he still has to remember to keep his voice down, which he says his family appreciates.
The makers of some of these devices also have had to be creative when it comes to battery power. The Otologics device is charged daily, for about an hour, by placing a magnetic coil on the skull. The magnet is wired to a battery pack, which can be worn on the belt so the patient is mobile during the charging.
Envoy's Esteem device is designed so it needs no daily recharging. But both devices need to be surgically replaced when the batteries die for good.
In the semi-implantable Vibrant Soundbridge, which is made by Med- El, batteries are simply placed in the external processor, and changed about once a week like a normal hearing aid.
The enthusiasm of some early adopters, despite the glitches and costs, shows how far some people are willing to go to have an alternative to conventional hearing aids.
Denver audiologist Lisa Evans-Smith, who is allergic to the materials used to make traditional external hearing aids, was one of the first patients in the U.S. to get an investigational Soundbridge device in one ear back in 1998. She then saved for five years and used some inheritance money to pay the $18,000 to get a device for her other ear in late 2006.
"I have them on all day and don't even know I'm wearing them," says Ms. Evans-Smith, 46. Unlike the fully implantable devices, the Soundbridge can't be worn in the shower. Ms. Evans-Smith says she has forgotten a few times and had to dry them out before using them again.
The Soundbridge device was relaunched in the U.S. last year after a hiatus of several years where few were available due to a change in manufacturing facilities.
Makers of the implantable devices say the technology is improving rapidly. Envoy's Esteem II, for example, has eight times the amplification power of the earlier device. Otologics' next-generation Carina will be 26% smaller.
Says University of Colorado otolaryngologist Herman A. Jenkins, lead author on Otologics' first clinical-trial publication: "It's a matter of time to make it better and better."
---
Ms. Johannes is a writer in Boston. She can be reached at [email protected].
