Adventures with Magnetic Loops

In 2010, the Anacortes Senior Activities Center (ASAC) Foundation board authorized funding to install a magnetic loop transmitter system. These systems are designed to improve the quality of reception of electrically transmitted audio for personal hearing aids, worn by the hearing impaired.

A loop system is similar to a hi-fi amplifier that drives speakers. In a loop system, however, the amplifier drives a coil of wire encircling a room. This wire generates a low frequency magnetic field that couples to a T coil in hearing aids. So, when an audio signal–voice or music–is applied to the amplifier input, the loop couples these audio signals directly into hearing aids in use by hearing-impaired located within that room. The advantage of this type of system is that there is no echoing from hard surfaces, and background sounds (noise) are minimized for the hearing-aid user. There are reports that this year U.S. sales will include T-coils in 89 percent of hearing aids. Europe has led the U.S. in loop installations, with their average being 90 percent.It appears though, that here in the U.S., we are beginning to close the gap.

Conceptually, the loop systems are simple devices. They have straightforward technical specifications needed to size both the power amplifier and the loop, which cover the physical area for hearing-impaired usage. Physical area can vary from a small system that loops a chair and sofa for television viewing, up to auditoriums that serve hundreds of people.

As in hi-fidelity sound systems, there are many opinions about a systems performance, from the users point of view. It was decided early on that the ASAC had to involve the end user of our proposed equipment throughout its specification, procurement, installation, and testing. Fortunately, there is a Hearing Loss Association Chapter that uses the ASAC as their meeting place, so we asked for and received much help from them in configuring and testing our system. As a result, the majority of the ASAC loop system users have been very satisfied with the performance of the system.

It was discovered that many gathering places for hearing impaired people in the Pacific Northwest are already looped. These include many churches, city meeting rooms, and other meeting places that the hearing impaired use. Many airports in Europe have loops installed in their public areas, so that hearing impaired people can hear any announcements being made. Locally, in Anacortes, there has been a spin-off that has resulted in three other facilities being looped.

For the Anacortes Senior Activity Center, the board decided to loop two rooms: a 650 square foot meeting room, and a 2440 square foot multipurpose room. It took several weeks of effort to get to that decision point. It required learning the suppliers of such equipment, and developing rough cost figures. Suppliers are generally located in Europe. However, we found a U.S. supplier whose vendor is located in Spokane, Washington, along with other agents located primarily in the mid-West.

It turns out that there are some regulatory standards that had to be met, for any system we would consider.These are International Electrotechnical Commission IEC 60118-4 ed 2.0 Electroacoustics-hearing aids, and the American Disabilities Act. We discovered that by working with a knowledgeable vendor/installer, our effort in studying and understanding these requirements was minimized.

Once we got through all the steps of funding approval, performance definition, vendor selection, equipment interfacing requirements (the system can be driven from microphones, computers, a multimedia system, etc.), physical location definition, and testing requirements, the installation went very smoothly. It took approximately one and a half days, with two people working, to complete the installation of both of the ASAC rooms. The hearing-impaired users are very happy with the equipment, and we hear nothing but good things.

I hadn’t expected to become involved with so many people to complete what initially looked like something as simple as setting up a high-fidelity music system. Ultimately though, the help I received and the can-do attitude of everyone involved, enhanced the quality of the ASAC facilities and capabilities for serving the senior citizens of Anacortes.

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