By Ruth Bentler and Kassie McLaughlin

Ruth Bentler

The University of Iowa has made a huge commitment to persons with hearing loss in its decision to loop all upcoming construction on the campus! As a result of the devastating flood of 2008, a number of buildings were damaged and will now be rebuilt at higher elevations (yes, even Iowa City has different elevations!). These include a new performing arts building, a new School of Music building, and a new Art Education building, to name only a few.

The decision of the planning committee to include loops in all public spaces (including classrooms) is noteworthy and should serve as a model for other universities as they consider both their responsibilities to persons with hearing loss as well as their fiscal responsibilities during building and remodeling.

WHY INDUCTION LOOPS?

The University of Iowa folks certainly did their homework into arenas, accessibility provision, and cost. Why did they choose induction loops? Because they are relatively easy to install, maintain, and use. But we are getting ahead of ourselves. Let’s review, briefly, the concept.

Kassie McLaughlin

In order to understand how induction loops work, an overview of the telecoil in the hearing aid is necessary. Within hearing aids, a coil of wire is wrapped around a ferrite material, such as iron, which is an efficient conductor of electromagnetic signal. Telecoils are standard in many hearing aids on the market.

Induction is the process of an electrical current inducing a voltage from a distance. An induction loop is a wire placed around a space, such as a classroom, that converts audio information from a microphone into an electromagnetic signal that the hearing aid’s telecoil can receive. The listener picks up the signal from the talker’s microphone directly (via the telecoil) rather than via the hearing aid microphone, which will also pick up environmental noise between the talker and the listener.

Induction loops fall into a category of instruments called assistive listening devices (ALDs). ALDs can help those who are hearing impaired by improving the signal-to-noise ratio, increasing the ease of listening, and allowing users to listen at a greater distance.

George Kahl, an Iowa City resident and loop user, owned and managed an assistive listening device store (called Sound Clarity) and has installed many loop systems over the years. He notes that he prefers the sound quality from loop systems over that from other ALDs he has tried to help him cope with his own hearing loss.

Because loop systems transmit the signal directly to his hearing aid, he finds that he gets greater improvement in the signal-to-noise ratio than hearing aids alone could ever provide, even those with directional microphones or noise-reduction schemes. Because the intended signal (music, speech, or the like) is sent directly to the hearing aid, other background noises are not amplified in the way they typically would be from the hearing aid microphone.

Another advantage of a loop system is that many hearing aid users already own the equipment (i.e., a telecoil) necessary to use it in venues where loops have been installed. Hearing aid users can simply switch to the telecoil mode and listen. People with unaided hearing losses or incompatible devices can check out equipment from most venues and listen to the intended signal through earphones.

In addition, using an induction loop meets the requirements set forth by the American Disabilities Act, specifically the 2010 ADA Standards for Accessible Design, which has a mandate deadline of March 15, 2012 for hearing instrument compatibility.

SOME DRAWBACKS

One limitation of induction loops compared to other similar systems, such as infrared and FM, is that signals can leak from one area to another. For example, patrons in a movie theater may pick up not only their own movie’s sound track, but also the overflow sound from the movie in the next theater. Spillover can also be a concern when privacy is important. However, in locations where there is only one signal that all patrons need to hear, the induction loop is a great option.

A second limitation of a hearing loop system is the cost of installation. The larger the loop system, the more expensive the installation. Looping a facility when it is under construction, as is the case here on the University of Iowa campus, is the most cost-efficient way to go.

THE TECHNOLOGY IS CATCHING ON

Loop systems are already commonly used in Europe. For example, in Britain, nearly all churches, auditoriums, and cathedrals are looped. So are Heathrow Airport, many train stations, the Tower of London, and taxicabs in Edinburgh.

Recently, loop systems have started to gain acceptance in the United States as well, in large part due to the grassroots movement started by David G. Myers and his group at hearingloop.org. In New York City, the Taxi and Limousine Commission has started a pilot study to investigate induction loops in taxicabs, and all the ticket booths in that city’s subway system are looped. Sertoma (SERvice TO MAnkind) has launched the Sound Investment Campaign, helping to improve access for those who are hearing impaired. All of this bodes well for those individuals who need a little boost in signal-to-noise ratio in their everyday environments.

Our own university planners here in Iowa deserve kudos for continuing this trend. They needed and accepted input from us in Communications Sciences and Disorders. Perhaps other universities can follow suit. If other Audiology Departments do a little pushing and shoving, as we did, campuses across the country can set the accessibility standard for all public places.

Ruth Bentler, PhD, is Professor and Chair of the Department of Communication Sciences and Disorders at the University of Iowa. Because of her work with hearing aids and acoustical factors that impact their effectiveness, she has served as a consultant to the university’s planning and building committees many times over the years. Kassie McLaughlin is an AuD student at the University of Iowa. She works in the Hearing Aid Lab on various projects related to hearing aid efficacy and effectiveness.