Loop Systems—The Best-Kept Secret in Town!
© March 2004 (revised February 2009) by Neil Bauman, Ph.D.
Question: Every once in a while I hear hard of hearing people talking about "loop systems." What are loop systems?
How can they help hard of hearing people hear better? Are they expensive?—D. B.
Answer: Good questions. Glad you asked them. Loop systems are truly wonderful. They let hard of hearing people hear ever so much better,
especially in group settings where they can't get close to the person speaking. For some reason, even though loop
systems give wonderful sound and are cost effective, they seem to be one of the best-kept secrets around. Few hard
of hearing people have even heard of them. Listen up. I'll let you in on this nifty secret.
Loop systems are a class of Hearing Assistive Technology (HAT)/Assistive
Listening Devices (ALDs) that work together with hearing aids to help hard of hearing people hear better. Other
classes of ALDs include such things as Personal Amplifiers (PockeTalker),
FM systems and infrared systems. Unlike
the above systems, you do not have to wear anything extra in order to connect to, and use, a loop system—no neckloops,
wires, silhouettes, receivers or headphones. All you need are your hearing aids equipped with telecoils.
Loop Systems Can Do All This and More
Imagine being able to hear your TV or stereo from anywhere in your house
as you move from room to room—and the sound stays exactly the same—sounding as if a person is talking directly
into both your ears at the same time. A home loop system can do this for you. Also, you can hook your home phones
into your loop system so you can hear on any phone in the house with both ears, whether the phone is amplified or not.
Learn how to hook your home phone into your loop system.
In fact, you can put any signal you want into a loop system. In addition to your phone, that may be your TV, radio,
stereo, computer, door bell or whatever produces a sound you want to hear. You can even set up a portable loop
system outside on the grass for an outdoor meeting or family gathering.
Did you ever dream of riding in your car and hearing the radio clearly without
road noise intruding, or clearly hearing the people in the back seat? This dream can come true if you loop your
car (or motor home or boat).
Do you wish you could go to a public meeting or church service and hear the
speaker/minister as clearly as if he were talking right into your ears—no matter where you are sitting—without
having to hook yourself to some ALD? Loop systems will do this too.
With loop systems you don't have to fuss around, hooking yourself up with
wires, neckloops, silhouettes or headsets to some ALD receiver. Furthermore, there is no extra paraphernalia to
lug around, nor do you have to worry about batteries dying at the most inopportune times and not having fresh ones
Furthermore, loop systems will accommodate as many people as can sit/stand
inside the loop—all without any extra equipment or cost. Therefore, with loop systems, you never have to worry
about there not being enough receivers to go around.
Did you ever get to a meeting late and find all the chairs at the front were
taken so you had to sit at the back where you couldn't hear? If the room is looped, this is not a problem—just
switch to your hearing aids to their telecoils and you will be able to hear loud and clear from the very back row.
You can use loop systems almost anywhere. Typically permanent loop systems
may be installed in various meeting areas such as public buildings and churches. In Europe, they are now installed
in many forms of public transportation—taxis, busses, trains and ships. Small systems can be installed at ticket
counters, bank counters, etc. You will also find loop systems in some schools and offices where there are hard
of hearing people.
Loop Systems Give Clear Sound
Loop systems provide wonderfully clear sound. This results in dramatically
increased comprehension and increased listening pleasure. Loop systems broadcast personalized sound to both of
your ears at the same time. Therefore, listening to a good loop system is like having the speaker talking right
into both of your ears
at the same time.
In case you are wondering, here's why loop systems produce such clear sound.
Speech is made up of various frequencies of sound. Basically, low frequency
sounds give speech its volume while high frequency sounds give speech much of its intelligence. When you hear all
frequencies properly, speech is clear and easy to understand.
However, as the distance between the speaker and your ears increases, a number
of things happen to degrade this clear speech.
First, as the distance increases, the volume decreases so you can't hear
as well. At the same time, higher frequency sounds attenuate (get softer) with increasing distance and finally
disappear altogether, leaving only lower frequency sounds. Without the high frequency sounds, speech is distorted
and becomes difficult to understand. Speech is further distorted by reverberation (echoes) in rooms—especially
those with high ceilings and/or hard surfaces. Finally, when there is a significant distance between you and the
speaker, sounds around you mix with the speaker's voice, burying his voice in a jumble of noise.
Loop systems address all these factors. First, sounds no longer get softer
the further you are from the speaker. In fact, the volume stays pretty much constant anywhere inside the loop.
Second, since the speaker is speaking into a microphone held about 3 or 4 inches from his mouth, high frequency
sounds are not lost in the air. Thus, it sounds like the speaker is speaking right into both your ears. Third,
reverberation is cut to a minimum as the sound of the speaker's voice goes directly into the microphone rather
than bouncing all around the room before reaching your ears. Finally, since the microphone is so close to the speaker's
lips, little extraneous sound gets into the sound system. Thus, the end result is clear speech.
How good are loop systems? I'm no stranger to loop systems having used them
for several years in different situations with good success. At a recent SHHH meeting, I decided to experiment
a bit and find out. The person speaking was using two microphones. One was hooked into the room's public address
system and the other was hooked into my portable loop system. Using my hearing aids' microphones, I could hear
the speaker fine as far as volume was concerned. However, the clarity of his speech was poor. Distance let the
high frequencies fall off and that, coupled with the reverberation and echoes in the room, made understanding him
difficult. In fact, I needed to speechread him in order to get his message—and I was sitting in the front row!
When I walked to the back of the room, the reverberation and noise combined with the increased distance made understanding
him even more difficult.
In contrast, when I switched my hearing aids to their telecoils, I could
hear everything the speaker said loud and clear. It was so clear I didn't even have to speechread. The difference
was dramatic—like night and day—no matter where I stood in the room.
One lady, after reading
this article, wrote to a hard of hearing group, "I want to thank Dr.
Neil at the Center for Hearing Loss Help for writing directions
that were totally comprehensible to this female mind, and taking the
time to answer my questions. The successful looping that I did in
the basement was evident when I got the Univox 2A [now Univox
DLS-50] out of the box and
plugged it in. Flipped the switch on my aids to M/T and it was like
Another lady wrote, "Last Thursday I ordered the Univox with pad
from Dr. Neil. He had the equipment shipped to California in just
two days. It arrived on Saturday. My husband's 80th birthday was the
next day. His son hooked up the Univox with no trouble, and then on
Monday, April 17, his hearing aid provider installed the needed
t-coil program and voila— it works like a charm. He is hearing TV as
he hasn't done in years!"
A man wrote: "Dear Dr. Neil: This has been the most useful web-site I found on any
system from any vendor on the entire internet! It was
packed with so much details, I couldn't believe it. I
was so excited I even ordered one late Saturday night,
and I can't wait for it to arrive. I found all of the
additional information you provided, such as how to
make a double loop, or hooking the system up to a FM
wireless system (which I have) or hooking it to the
telephone, extremely useful. I was so amazed that you
even provided specific model numbers from Radio Shack,
such as what type of patch cord to use for hooking the
amplifier to the wireless FM system or what to buy for
using the system in the car. No other site provided
such information. You answered every single question
I could think of and addressed every issue (such as
using a boom microphone for the telephone), it was truly
amazing. I just want to personally thank you so much
for all the information you provided."—J. G.
If you are already drooling at the thought of owning your own loop system,
order a loop system for yourself now.
How Loop Systems Work
Loop systems consist of three basic parts—a microphone or other input device,
a loop amplifier (Learn about the two basic kinds of loop amplifiers.) and a loop of wire. That's
it for the transmitting side. Your own hearing aids equipped with telecoils make up the receiving side.
To set up a loop system, all you do is plug the loop amplifier into a wall
socket, plug the input device or microphone into the loop amplifier, string a loop of wire around the perimeter
of the room or area you want looped and connect the ends of the wire to the loop amplifier and turn it on. That's
Audio signals are picked up by the microphone or directly from some sound
source like your TV or stereo. They are amplified by the loop amplifier and then travel through a loop of wire
that surrounds the listening area. The wire loop is used instead of regular loudspeakers. When the sound signal
travels through the loop of wire, it produces a magnetic field in the looped area that mirrors the frequency and
intensity characteristics of the original sound signal. At this point, the loop system's job is done.
Now, it is your hearing aids' job to convert this magnetic signal into sound
you can hear. When you switch your hearing aid from its microphone to its telecoil, all you are doing is connecting
a small coil of wire to the input of the hearing aid's amplifier instead of its microphone. This tiny coil of wire
is sensitive to nearby magnetic fields such as the one produced by the loop system. The changing magnetic field
in the room loop induces a corresponding electrical signal into the telecoil. The hearing aid amplifier then amplifies
this signal and you hear a faithful reproduction of the original speech signal.
This process of inducing an electrical current in one wire as a result of
current flowing in a nearby wire is called induction—hence the term induction loop system—or just "loop system"
Since any electrical current will result in a magnetic field, depending on
their location, loop systems may be prone to interference. This interference is usually a buzzing or humming sound.
This resulting buzz or hum may be so loud that you can't use the loop system in certain places. Typically, interference
can come from nearby electrical wires, fuse boxes, TVs, computer monitors and fluorescent light fixtures.
In order to tell if the area you want to loop is free from interference,
all you need to do is switch on your telecoils, turn up the volume on your hearing aids and listen. If you hear
loud buzzing, that is not a good place for a loop system. As you move around, you will notice that the interference
level changes. Set up your loop system where the interference is non-existent or negligible.
Telecoils: The Other Half of the Loop System
The loop wire is the transmitting half of the loop system. The receiving
half is the telecoils in your hearing aids.
A telecoil is just a tiny coil of wire inside your hearing aid that picks
up electromagnetic signals given off by various devices including loop systems and telephone handsets.
Tibbetts telecoils Photo courtesy www.tibbettsindustries.com
There are a variety of names by which people refer to telecoils. They may
call them T-coils, T-switches, telecoils, telephone coils or audio coils. It doesn't matter. All refer to the same
thing—a tiny coil of wire in your hearing aid.
In order to use a loop system, you must have hearing aids equipped with telecoils.
Unfortunately, a good number of hard of hearing people do not even know whether their hearing aids have telecoils
installed or not. Before you buy a hearing aid, you should insist that it have good amplified telecoils installed.
Telecoils got the name "T-switch" from the switch on the analog
aids that typically switched between "M" for microphone, and "T" for telephone.
Ideally, your hearing aids should have a three position switch (for analog
aids) or three programmable modes (for digital aids). These three modes are "M" for microphone only,
"T" for telecoil only and "MT" for both microphone and telecoil together.
This combined microphone/telecoil mode is important. Here's why. When you
have your hearing aids in the "T" mode, you can only hear what comes through your telecoils. For example,
if you are in a meeting and the person sitting next to you asks you a question, you won't hear him at all. You'd
have to switch your hearing aids back to the "M" setting and have the person repeat the question. In
the meantime, you'll be missing anything coming through the loop system.
With the "MT" position, you'll be able to hear both through the
loop system and people talking around you through your hearing aids' microphones. This is a nice feature. For example,
you may be listening to your TV at home though a loop system. If it is quiet and you have your hearing aids set
to the "MT" position, you can listen for the baby crying or the doorbell or phone ringing at the same
time you are hearing the TV.
Later, if there is a lot of noise around you (the kids are up making a racket
near you), you can switch to the "T" position and cut out all this interference and just hear through
the loop system. This way you can have the best of both worlds!
If you cannot get hearing aids equipped with a "MT" function, all
is not lost. At home you can work around this by hooking both a microphone and a TV, for example, into your home
loop system. The loop system's microphone will pick up the kids crying, the doorbell ringing or any other sounds
around you and superimpose these sounds on top of those from the TV and you will hear both though your hearing
When you buy new hearing aids, if you are smart, you will insist they have
telecoils installed. However not all telecoils are created equal. Some are good and some not so good. Also, you
may notice that when using your telecoils, if you tilt your head while listening to a room loop the sound changes
If there is a strong loop signal, this may not matter at all—especially if
you have amplified telecoils (telecoils with a tiny amplifier attached). However, if you are sitting where the
signal is weaker, you may notice that you hear better with your head held at a certain angle. Experiment a bit—tilt
your head at different angles and discover the best angle at which to hold your head for the strongest signal.
In one looped meeting, I noticed that if I held my head up, I could hear well, but whenever I looked down to make
some notes, the signal almost faded away. The same thing can happen when using a phone. How you hold a phone up
to your telecoils makes a difference in how loud you hear the person talking.
The way your telecoils are physically oriented in your hearing aids is important
if you are going to get the best use out of them.
Learn more about telecoils and why correct orientation is so important.
Setting Up a Loop System
Setting up a portable loop at a meeting or gathering is easy. Just string
the loop of wire around the room and tape it down with masking tape or duct tape wherever people may walk so they
won't trip over it. Attach both ends of the loop wire to the loop amplifier. Plug a microphone into the loop amplifier
and clip it on the speaker. Turn the amplifier on. Now anything the speaker says will be transmitted through the
loop to anyone wearing hearing aids equipped with telecoils.
At home, you can run the wire loop around the edge of a room—stringing it
over doorways or you can place it under the edge of a carpet. If you loop your whole house, the easy way to do
this is to staple the loop around the edge of the ceiling in the basement. That way you will be able to hear anywhere,
both on the main floor and
in the basement.
Depending on the power of your loop amplifier, you can loop a room, several
rooms or your whole house. That way you can move around in the looped area and still hear what you want to hear.
Learn how to make a double wire loop.
If you just want to loop your favorite chair (or car seat), setting up a
personal loop system is as simple as putting a special loop pad under the cushion of your favorite chair or under
the seat of your car and plugging it into the loop amplifier.
Use this chart of wire sizes to determine the
correct wire size for the loop amplifier and size of loop you are using.
If you are hooking up a loop system in a church or other public building,
here are a couple of signs you can print to
indicate that an audio loop system is installed.
Hooking Your Univox to Your TV
There are a number of ways you can hook your Univox to your TV (or other
audio device). Click here to learn how to connect you
Univox loop amplifier to your TV.
But I Don't Have Hearing Aids—Can I Still Use A Loop System?
The good news is yes, you can. If you don't wear hearing aids, you can
purchase a loop receiver and reap the same benefits of beautiful clear sound as
do people with t-coils in their hearing aids.
Learn more about Loop
Adjusting the Univox DLS-50 Power Level
It is important to adjust the power input into the loop pad or room loop
correctly so your Univox won't get too hot. Click here
for instructions on setting the power correctly.
Getting a Loop System for Yourself
What does a home loop system cost? The good news is that home loop systems
are relatively inexpensive—in the neighborhood of $200.00. The Univox DLS-50
(described below) costs even less.
Loop systems are especially nice whenever there are two or more hard of hearing
people together. With a loop system, each person doesn't need any extra equipment.
You could accomplish the same thing a loop system does with an FM system
for example, but each person would need an FM receiver and a neckloop to connect the receiver to their hearing
aids. With more than one person, this quickly gets expensive. The whole loop system only costs about 1/3 to 1/2
of what a basic FM system would cost for just one person, yet the loop system can handle as many people as you
want to pack into the looped area at no extra cost.
There are several loop systems on the market. Some are big systems for large
public buildings and others are small systems suitable for home and portable
use. One of the best (or perhaps the very best) of these home systems is the
Univox 2A [now Univox DLS-50]. This is the system I use and like.
You can use the Univox system in your home using the supplied wall plug. For
your car or other vehicle, just plug it into a cigarette lighter socket.
Furthermore, you can use the Univox DLS-50 with a wire loop or a loop pad for personal listening (or both).
The Univox 2ATM has three neat features. You can adjust the treble and bass characteristics of the
loop to fit your particular hearing needs. Furthermore, you can control the power going into the loop to match
any listening situation.
My friend, Denise Portis, is thrilled with her Univox 2A [now Univox DLS-50]. Read her touching account of hearing again using a room loop.
What the Univox loop system has done for her, it may also do
Learn more about the many features of the Univox and/or order a loop system for yourself. You do not have to continue to strain to hear. If you're like me, once you have used a loop system, you'll never want to go back to hearing with just your
hearing aids alone.
Loop Systems Articles Index
Products— features and specifications
of loop amplifiers and related accessories and links for purchasing them
Loop amplifier technical specifications
and installation guides
Chart of recommended wire sizes for the various
Univox loop amplifiers
Instructions for setting the loop power level correctly
Two signs you can print indicating that an audio loop system is installed