Telecoils

Telecoils-by-Mark-Ross

You may have heard the telecoil in your hearing aid referred to as a telephone switch, a T-switch, or a Tcoil. Whatever you call it, it’s one of the most important features of a hearing aid. It makes talking on the telephone much easier; but it also opens up the world of assistive listening devices, including the induction loop technology that is so widespread in Europe (and becoming more so in the US).

In my opinion a properly fitted and adjusted pre-amplified telecoil should be included in EVERY hearing aid.

  • August 2001 – Interested in how a Tcoil works? How about what makes a telephone hearing aid compatible? Ron Vickery’s interesting article explains these concepts and lots more about telecoils and telephones.
  • January 2005 – David Myers reports that half of hearing aids sold in the US now come with telecoils!
  • February 2005 – Confused about telecoils? Wondering what they are or what they do? Then check out this primer. It will answer all your questions!
  • March 2005 – Here’s Dr. Mark Ross on telecoils.
  • June 2006 – Technology shows promise in reducing telecoil interference
  • August 2006 – Telecoils are about more than telephones
  • August 2006 – Nanotechnology improves touchless telecoils
  • September 2006 – Getting the Best Telecoil Response
  • October 2006 – T-Coils: Beyond the Telephone
  • January 2007 – Arizona Bill Requires Education about Telecoils
  • April 2007 – Arizona Requires Dispensers to Inform Consumers About Telecoils
  • November 2007 – Hearing Aids Alone Won’t Do the Trick
  • January 2008 – Should Kids’ Hearing Aids Have Telecoils?
  • July 2008 – The Lowly Telecoil
  • October 2008 – Experts discuss telecoils and the future of hearing aid-compatible assistive devices
  • August 2009 – Everything You Wanted to Know About Telecoils – And More!
  • January 2010 – Getting the Most from your Telecoil
  • November 2010 – Technology shows promise in reducing telecoil interference

More on this and related topics

Technology shows promise in reducing telecoil interference

June 2006

Because the sources of interfering magnetic fields are generally located several feet or more from the hearing aid’s telecoil, the field strength of these “far-field” sources is relatively uniform within the shell of the aid. Researchers at Global Coils SAGL, a joint venture between Tibbetts Industries, Inc., of Camden, ME, and R. Audemars SA of Cadempino, Switzerland, have developed an approach to the mitigation of this predominant mode of interference with “far-field canceling” (FFC) telecoil technology.

Telecoils are about more than telephones

August 2006

When Sam Lybarger labeled the small induction coil he used to access the magnetic leakage from telephones a “telecoil,” he could not have foreseen that the ramifications of that decision would be bedeviling us some 60 years later. In 1947, his decision made perfect sense and, when used with telephones, the term “telecoil” still makes perfect sense. But, as can be seen from the two companion articles relating to telecoils in this issue (by David Myers and William Diles), these little structures can provide auditory access to much more than telephones. As these articles demonstrate, telecoils are being employed to hear auditory signals in a wide variety of situations.

Nanotechnology Improves Touchless Telecoils

August 2006

By contrast, Destiny contains a piece of nanotechnology called a giant magnetoresistance (GMR) switch, which uses electron spin rather than magnetic charge to sense signals and store information. Developed for Starkey by Eden Prairie-based NVE Corporation, the sensors consist of layers of magnetic thin films just a few atomic layers thick–about one-third the size of the mechanical reed switches that hearing aids typically use. This makes the sensors small and sensitive enough to use in even the smallest of hearing aids–a completely-in-the-canal (CIC) device–and allows the Destiny aid to quickly switch modes automatically as a wearer picks up a phone. And this isn’t a help solely over the phone lines. “We’re hearing that for the first time that people don’t want to take their hearing aids out even when they go to bed, because they’re not getting any feedback from the pillow,” [Starkey R&D executive Tim] Trine says.  

Getting the Best Telecoil Response

September 2006

Question: I need to purchase a new hearing aid, and neither my audiologist nor I can find a hearing aid that has pre-amplified telecoils. I have tried several hearing aids with conventional telecoils and find it difficult to hear on the phone, even with an amplified phone. I have read many, many articles telling consumers to ask for a pre-amplified telecoil, so my audiologist and I are looking for a hearing aid with this feature, but we have not been successful in finding one.

Here’s the answer!

T-Coils: Beyond the Telephone

October 2006

T-coils (also called induction pick-up coils, or magnetic induction systems) have existed within personal hearing aids since the late 1940s (Ross, 2004). T-coils can be thought of as mini-antennas, which receive magnetic information. T-coils are in the majority of new hearing aids and their popularity continues to rise. In 2001, only 37% of all dispensed hearing aids contained T-coils, whereas in 2004, 52% of dispensed units contained T-coils (Kirkwood, 2005) . . . . Unfortunately, telephone-centric names (“T-coil,” “t-coil,” “telecoil,” etc.) infer the primary application of this technology is indeed, telephone-based. Although certainly telephone-based communication was the primary impetus for Lybarger’s development of the T-coil almost 60 years ago, and telephone use is by far the most popular current application, T-coils in 2006 offer far greater application than their telephone-based names imply (see Ross, 2006).

Should Kids’ Hearing Aids Have Telecoils?

January 2008

“Wait, just a second…” (moving to another spot)…OK, can you hear me now?” We all know these TV ads from a national wireless carrier, and they’re funny because the situations are real and we may find ourselves repeating the same phrase, sometimes laughably. But it’s no laughing matter for a parent or grandparent trying to be heard on the phone when speaking to a child with hearing loss. Do we think about telecoils for children in the same way we do for adults? Telecoils have been around on BTEs since the late 1940s. Since then, telephone access technology has gotten much more sophisticated with innovations like programmable telecoils, touchless T-coils and acoustic phone programs?not to mention the improvement afforded by feedback cancellation technology when using the phone. According a recent survey, T-coils are now in 54 percent of all new hearing aids and audiologists reportedly include telecoils in 70 percent of hearing aids. Unfortunately, statistics are not available on hearing aids fitted to children, but we do know that almost all BTEs contain a telecoil and BTEs are the instrument of choice for most children.

Experts discuss telecoils and the future of hearing aid-compatible assistive devices

October 2008

So old, and yet so promising. That describes the venerable telecoil and its modern applications. In some European countries, telecoils now routinely come with hearing aids and serve a dual purpose: to enhance telephone conversation and enable hearing aids to serve as customized, wireless speakers for broadcasting sound. In most churches with a PA system, in auditoriums, in every London taxi, and increasingly at bank teller stations, train ticket windows, pharmacy counters, and tourist information stations, induction loop systems broadcast sound directly to hearing aids. (The sound transmits to the telecoil sensor via magnetic energy from a wire loop around the listener.) In the United States, assistive listening is mostly hearing aid incompatible. But telecoils, and the hearing aid-compatible phones and assistive listening they enable, are making strides . . . .  To explore the significance of these developments for hearing professionals, hard-of-hearing consumers, and the hearing industry, The Hearing Journal invited me to convene a virtual conversation among several experts. 

Technology shows promise in reducing telecoil interference

November 2010

A November 2002 Knowles MarkeTrak VI study investigated what improvements in hearing instruments the most current users would appreciate.1 The study’s author, Sergei Kochkin, PhD, reported that more than eight out of ten consumers would welcome improved performance in understanding speech on the telephone. In fact, only 38% of users said they were satisfied with their telephone hearing experience. These findings suggest that the increased use of telecoils and improvements in telecoil technology would raise the level of user satisfaction with hearing aids.

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