Staying in the Loop: When Hearing Aids Are Not Enough

Editor's Note: Dr. Diles wrote the article below for our consumer website (www.healthyhearing.com). However, as it was so useful for so many patients, we are making it available here, with Dr. Diles' permission, for the professional reader, You may download and print copies, and place them in your office waiting room, or use them as handouts for educational seminars. Special thanks to Dr. Diles. ---Dr. Douglas L. Beck, Editor-In-Chief www.audiologyonline.com, and www.healthyhearing.com

Introduction:

People with hearing loss often struggle to catch television's fast-paced dialogue even with well fitted, advanced digital hearing aids. Intelligibility breaks down much faster when background noise is present, when distance from the sound source increases, and when poor room acoustics are apparent. Closed Captioning (CC) can be helpful, but hearing is generally preferred to reading captions.

Infrared, FM and induction loop are wireless sound transmission systems that help people hear TV and other sounds (radio, CDs, DVDs, conversational speech, etc.) more efficiently.

Induction loop technology is the oldest and the most popular of the three wireless technologies. Induction loops have a distinct advantage -- they work with the individual's t-coil equipped hearing aids. The user does not have to remove his/her hearing aids to use the loop system.
In our experience, t-coils are more effective with TV home loop systems than they are with telephones.

According to Mark Ross (2002), "The ordinary telecoil is perhaps the most common and most underestimated assistive listening device available for hearing impaired individuals today." Dr. Ross stated, "It would be useful if we could re-label this little coil in order to stress its potentially wider application. Perhaps it is time to change its name. Maybe if we termed the "telecoil" a "listening coil" or "audio coil" we could be more effective in communicating its full scope as an ALD".

Induction Loop Components:

Induction loops consist of three basic parts: a microphone, a loop amplifier and the loop wire. The audio output signal from the TV, DVD, CD, radio, etc., is routed to the input of the loop amplifier and the amplifier's output is connected to the loop wire. The amplifier strength can vary, and the amplifier strength dictates the area of coverage. The receiver is the t-coil in the personal hearing aid(s) of the listener. The magnetic field strength must be high enough to produce an acceptable signal-to-noise
ratio (SNR) but not so high as to cause overload of the hearing aid.

All hearing aid t-coils work with all loop systems, regardless of hearing aid or loop manufacturer. While the user is located within the field created by the loop wire, the receiver (the t-coil of the hearing aid) will receive the electromagnetic signal from the loop. There is no loss of signal when nearing the edge of the loop. However, you can get "spillover" several feet outside of the loop wire itself. Therefore, loops are not appropriate choices for adjacent rooms in close proximity. Although loops are simple in terms of technology, they are very important regarding quality of life issues.

Audiometric Considerations:

There are no audiometric contraindications regarding loop recommendation or usage. Individuals with any type and degree of hearing loss, and any t-coil equipped hearing aids, can benefit from loop technology. Patients with poor word recognition scores are often well-suited for loop technology due to the advantageous signal-to-noise ratio when listening through the loop. Binaural listening via binaural t-coil-equipped hearing aids allows the best possible hearing perception. Patients typically report greater speech intelligibility while using a home loop system, than they would obtain with their hearing aids alone.

Direct and Exclusive Sound Issues:

Although at first, it may seem like a good idea to have a "direct and exclusive" sound from the sound source, such as the TV, sometimes an exclusive sound connection can be isolating, and arguably dangerous - as other sounds (sirens, fire alarms, door bells, telephones) may not be perceived by the wearer. Hearing aids with an M/T switch allow sound from the environment to be heard along with the sound from the loop system, and this is generally advised. The listener using a loop system can appreciate additional environmental sounds without auditory isolation. All other ALDs designed for home TV listening require isolating headphones and hearing aid removal.

Installation:

Room loops for residential applications do not require special considerations and installation can be done without a professional. There's no need for an expensive electrician or carpenter. The physical installation of the loop system is arguably one reason audiologists may be hesitant to recommend these products.

With just a few "handyman" skills, you can run the wire around the edge of the room, over the doorways or under the carpet. Securing the wires to the basement below or the attic above, with a staple gun to encircle the TV room is an effective installation technique. Patients often accomplish installation themselves, or the audiologist can arrange for installation. Installers are easy to find and most installations take less than one hour and once installed, loop systems are virtually maintenance free.

In Office Loop:

Our office has been looped for several years. Our treatment rooms, as well as our reception area, have been looped. Demonstrations are accomplished using cable television during regular fittings or follow up appointments, and even while the patient waits in the reception area. The loop system in the reception area is connected to the "audio out" port of the TV, and there is no acoustic signal sent to the room. We have a sign that instructs people to switch their hearing aid to the "T" position to hear the TV. People are always amazed by the clarity and audibility, and it generates lots of questions and interest. Our front office staff is well prepared to explain the technology.

Loops available internationally:

Induction loop technology has been available for decades and is commonly found in public and private places across Europe and the United Kingdom. Why don't we see more loops in this country? It has to do with the prevalence of t-coils. All hearing aids dispensed in England come equipped with t-coils, whereas approximately 48% of hearing instruments dispensed in the USA include t-coils.

Perceived Value of Loop Systems:

Another reason why we may have fewer loop systems in the USA could be the result of the previous perception of value. Years ago, when the cost of a high quality state-of-the-art analog hearing aid was $750, it was difficult to convince a patient that an additional $300 for a loop system was a good investment. Now that high quality digital hearing aids are in the $1500-$3000 range, an additional $200-$300 spent on a home loop system seems relatively inexpensive and provides a better overall value. Home loops have actually come down in price in recent years and t-coils are standard in most BTE and many ITE instruments.

Costs and Supplier:

While there are several loop systems available, the loop system we use is the recently introduced "Field," available from Phonic Ear of Petaluma, California. The Field comes complete with the amplifier, microphone, power supply and 135 feet of wire, to cover an area of approximately 30 ft x 30 ft -- large enough for most home TV situations. The Field is equipped with dual AGC functions and volume and tone controls. The MSRP of the Field is $205 for the hardware. If the patient self-installs, obviously there is no additional charge. If the patient requests installation, we provide it for an additional fee.

Summary:

Loop systems are not just for public places anymore. Home by home looping is making a difference in the lives of hearing aid users. Background noise, distance and reverberation are no longer a problem while using a loop system. Loop systems work with hearing aids, and therefore, are more likely to be used. Recommending t-coils and home loop systems is one of the best ways to increase hearing aid satisfaction rates.

For more information on induction loops, www.hearingloop.org

For more information about our home loop installation program, www.goodhearing.com

For more information about Phonic Ear, www.phonicear.com

Additional Recommended Readings:

Hearing Aid Compatibility and Wireless Assistive Devices. Myers, David G. (2005). The Hearing Review. 12 (1).

Telecoils deserve wider acceptance as assistive listening devices. Ross, Mark. (2004). The ASHA Leader. p. 1.

Interview with Dave Myers, Professor of Psychology, Hope College Topic: LOOPING America www.audiologyonline.com/interview/displayarchives.asp?interview_id=279

T-Coils: Getting the Most Out of Your Hearing Aid Nancy L. Aarts, Ph.D., Assistant Professor, University of South Alabama www.audiologyonline.com/articles/arc_disp.asp?id=1203

References:

Ross, M., Telecoil and Telephones The Most Commonly Misunderstood "Assistive Listening Device", Hearing Loss; The Journal of Self Help for Hard of Hearing People, January/February 2002.

Ross, Mark, Telecoils as Assistive Listening Devices, www.hearingresearch.org