Friday, October 23, 2009

Using Telecoils to Turn Hearing Aids into Mini Loudspeakers

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Whereas standard behind- and in-the-ear hearing aids work well in relatively quiet, more intimate settings, these devices often lose their effectiveness in larger, public spaces where background noise puts the hard of hearing at a disadvantage. Although the technology to solve this problem—induction-loop systems that broadcast sound directly to hearing aids and cochlear implants—has been available for years, implementation has lagged, advocates say, because not enough is being done to promote their use.

An induction-loop system, also called a “hearing loop,” captures electromagnetic waves produced by a microphone, public address system or telephone receiver and broadcasts these signals directly to the hearing aid in a person’s ear, provided that it is equipped with a tiny copper telecoil wire that can pick up the signal. (Hearing loops can also broadcast signals to cochlear implants, which are surgically implanted electronic devices that bypass damaged or nonworking parts of the inner ear and directly stimulate the auditory nerve.) A hearing loop could be as small as a piece of wire worn around the neck (called a neck loop) or a large as a ring of cable placed around the perimeter of a room or space.

Normally, a hearing aid captures sound with its microphone then amplifies this sound for the wearer, according to the Hearing Loss Association of America. A hearing aid equipped with a telecoil can cut through ambient noise by shutting off the normal microphone, enabling the wearer to tune in directly to the sounds being broadcast. Telecoils can also pick up magnetic signals emitted by landline telephones, which means someone wearing a telecoil-equipped hearing aid can set the phone receiver down and still hear what the person on the other end of the line is saying. Most cell phones are not compatible with hearing aids, although some are equipped with Bluetooth that can wirelessly pick up sounds from Bluetooth-enabled cell phones. (A downside to Bluetooth is its power consumption, which greatly cuts down on a hearing aid’s battery life.)

Telecoils work somewhat like Wi-Fi for hearing aids, enabling them to serve as customized, wireless loudspeakers, says David Myers, a psychology professor at Hope College in Holland, Mich., and creator of, a Web site that advocates for the technology.

Hearing aid–makers are increasingly equipping their devices with telecoils. More than 60 percent of hearing aids come with telecoils, up from 37 percent in 2001, according to a study in the April 2008 issue of The Hearing Journal (.pdf).

Still, although there are about 36 million Americans with hearing loss, says Myers (himself hearing impaired), hearing-loop technology has not been as widely embraced in the U.S. as it has in other regions of the world, particularly in northern Europe. Myers first became aware of the technology more than a decade ago while worshipping in Scotland’s Iona Abbey, where the building’s poor acoustics prevented him from clearly hearing the service being performed. At his wife’s prompting, Myers switched on his hearing aid’s “T” (for telecoil) setting to see what would happen. “The sudden clarity was overwhelming,” he adds, “an experience that I have since had in countless other British venues, from auditoriums to cathedrals to the backseats of London and Edinburgh taxis.”

Since then, Myers and others have worked to introduce the technology to an increasing number of venues in the U.S. Myers alone went to hundreds of western Michigan venues, including 40 rooms in Grand Rapids’s DeVos Place Convention Center and both concourses and all gate areas of that city’s Gerald R. Ford International Airport

The primary reason for the U.S.’s lagging adoption of hearing loops is that the technology is not a requirement for public venues, Myers says. The Americans with Disabilities Act (ADA) has, since it was revised in 2004, required public venues in the U.S. to offer assistive listening systems (ALS) for people with hearing loss, but it offers movie theaters, concert halls, sports arenas and other gathering places the option of installing hearing loops, providing neck loops (a wire worn loosely around the neck that’s connected to a receiver and works with a hearing aid’s telecoil like a mini hearing loop) or offering visitors a cigarette pack–size receiver that tunes into broadcast signals via FM or infrared waves. The latter comes with earphones (the hearing aid may need to be removed) and is generally borrowed from the venue for the duration of a performance or event.

The ADA’s position is that no single approach works for every person and every venue. An FM system may be better than an infrared system in some open-air assemblies because infrared signals are less effective in sunlight. On the other hand, an infrared system is typically a better choice than an FM system where confidential transmission is important because it will be contained within a given space. “Differences in confidentially, interference, cost, installation requirements and operability make it impossible to simply use one type of ALS in every place,” according to ADA guidelines.

Myers disagrees, pointing out that a lot of people with hearing loss are self-conscious about asking the staff of a theater or other venue for an earphone setup, whereas others are averse to using earphones worn by the general public.

Another stern advocate of hearing loops is Janice Schacter, chair of Hearing Access Program, an organization she started in 2002 to advocate for those with hearing loss, including her daughter. “The ADA refers to places providing effective communication for people who are hard of hearing, but no one knows what that means,” she says. “I set out to find out what effective communication would be.”

Like Myers, Schacter has successfully advocated for hearing loops. New York City’s Taxi and Limousine Commission (TLC) last month approved hearing loops for any of its licensed drivers who wish to voluntarily install the technology in their vehicles. This came after a 13-month pilot program , set up with Schacter’s help, during which 15 taxis tested the technology. Another project in the works is the installation of hearing-loop technology at up to 642 information booths in the New York City subway system, says Schacter, who worked with Mayor Michael Bloomberg’s office to launch the initial pilot test at the Wall Street station. – Scientificamerican

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