Assistive Listening Device Primer
Editor: Here's a great article on Assistive Listening
Devices (ALDs) brought to you from the League for the Hard of Hearing
via bhNEWS. You might want to hang on to this so you can give copies to
people who ask you about these devices.
New/revised, from the League for the Hard of Hearing
Assistive Listening Devices
Joshua M. Gendel, Director, Assistive Technology Center
Q: Why do we need Assistive Listening Devices?
A: While the efficacy of modern hearing aids has long been
established, many hearing aid users will still experience difficulty
hearing in various situations. For these individuals as well as for
individuals who do not wear hearing aids, the properly chosen assistive
listening device (ALD) can prove invaluable in helping to alleviate
Q: What types of ALDs are there?
A: ALDs can be divided into two basic categories, alerting devices
and communication devices. An alerting (or alarm) device would indicate
that something important is occurring whereas a communication device
would facilitate the reception and understanding of spoken material.
Q: What types of things can an alerting device tell us?
A: An alerting device can tell us that it's time to wake up, there is
someone at the door, the telephone is ringing, the baby is crying or a
smoke alarm has gone off.
Q: What are the different ways an alerting device can tell us
something important is happening?
A: An alerting device can indicate that something important is
happening by producing sound, extra loud sound, light, vibration or a
combination of some or all of these.
Q: I have trouble hearing my doorbell but live in apartment and don't
want to get an extra loud bell because this might disturb my neighbors.
What can I do?
A: A common problem with doorbells is that the bell cannot be heard
in a distant room. There are wireless doorbell systems in which the
sound producing element (or receiver) can be placed at a location far
away from the pushbutton (or transmitter) such as a bedroom, basement or
attic. In addition, it is possible to use multiple receivers that can
produce sound in more than one location at the same time which can make
it possible to hear the doorbell in different locations within the same
house or apartment.
Q: The small battery operated alarm clocks are just not loud enough
for me to hear. What can I do?
A: Some people use a radio clock set to a loud volume and tuned to a
news station. There are still mechanical alarm clocks available which
some people find easier to hear. There are also extra loud alarm clocks
that can also be used with a flashing light and/or a bed shaker. In
addition, there is a small battery operated vibrating alarm clock that
can be placed under the pillow and is especially useful for people who
Q: If I use a flashing light for the doorbell, what happens if I'm in
another room when the doorbell rings?
A: Many flashing light ALDs can also be used with remote receivers.
These receivers can be plugged into other outlets in the house or
apartment and have an outlet into which a lamp or light bulb can be
plugged. When the main unit is activated, the remote units will also be
activated causing the lights that are plugged into them to flash. The
main unit communicates with the remote units by sending a high frequency
signal over the house AC wiring so that no additional wiring is
required. You can have as many remote units as you need.
Q: If I want to have a remote unit flash a light when the phone or
doorbell rings and the light flashes, how do I tell whether the my phone
is ringing or there is someone at the door?
A: The rhythm of the flashing will be very different depending on
whether the telephone is ringing or there is someone at the door so that
it is very easy to tell them apart.
Q: Are there alarm devices that can be used with body worn receivers?
A: Body worn receivers are available which will vibrate and indicate
the nature of the alarm condition. In addition, there are units
specially designed to be used by people that are deaf-blind.
Q: What are some smoke alarm ALD issues?
A: Individuals with normal hearing can usually hear a smoke alarm
even when it has gone off in another room or area of the house so that
there is no problem with using separate and independent smoke alarms.
Using separate and independent smoke alarms that have flashing lights
may present a problem if the individual is in another room and does not
see the flashing light. The best type of separate flashing smoke alarms
to use in this case would be those units that have the capability of
being wired in tandem so that if one of them goes off, all of them will
go off so that the flashing can easily be observed no matter where one
happens to be within the house or apartment.
In addition to flashing lights, there are also smoke detectors with a
built in radio transmitter that will cause a receiver unit to activate a
bed shaker causing it to vibrate. With this type of system, it is
possible to use more than one smoke detector/transmitter so that smoke
detection is available at more than one location.
Q: What types of communication ALDs are there?
A: Basically, communication ALDs are used for the telephone, TV, the
movies, theater, lectures, and noisy situations.
Q: I'd like to get a louder telephone - what's out there?
A: There are a number of possibilities - you may be able to make your
present telephone louder (described below). There are also complete
telephones available with built in amplification. These usually have
other useful features as well such as a tone control, an extra loud ring
and a flashing light.
Q: What exactly is a T coil?
A: A telephone coil is small coil of wire within the hearing aid
activated by a switch on the hearing aid which allows the hearing aid to
pick up the phone signal directly. It will also prevent feedback and
cuts out surrounding noise when making a phone call. A telephone whose
ear piece emits a magnetic field that can be easily picked up by a
hearing aid telephone coil is said to be hearing aid compatible. The
telephone coil can also be used to easily and conveniently enable a
hearing aid to work with various other types of ALDs.
Q: Can I do anything to make my existing phone louder?
A: There is a portable snap on telephone amplifier which can be used
with virtually any telephone however it may have to be attached and then
removed each time the phone is used so that the phone can hang up
properly. Also available are in-line telephone amplifiers which can be
used with modular phones (where the handset can be unplugged and
separated from the desk set) as long as they do not have the dialing
keypad in the handset. These can be attached to just about any phone and
can be left in place.
Q: What about cordless phones?
A: There are cordless phones with built in extra amplification that
are available. In addition, some of them have jacks that can be used
with a hands free accessory. Some models also have a special jack into
which special accessories such as a neck loop can be plugged into.
Q: I travel a lot and sometimes have trouble using local telephones -
A: Many travelers find the portable snap on telephone amplifiers very
useful. In addition, this device can also be used to turn a non hearing
aid compatible telephone into one that is hearing aid compatible.
Q: What is a TTY?
A: A TTY (or TDD) is a device by means of which an individual can
type to someone at the other end of the phone line who also has a TTY
and can then read the response that has been typed back.
Q: What if I want to communicate with a TTY user but don't have a
A: You can go through the national relay system by means of which you
speak to a special relay operator (called a communication assistant or
CA) who would then type (or relay) the information to the TTY user. The
TTY users typed response is then read back to the hearing caller. This
service is available throughout the US and is accessed by dialing a
special 1-800 telephone number or by dialing 711.
Q: No matter how loud I turn up my amplified phone, I still have a
lot of trouble understanding what is being said - what can I do? I might
consider using a TTY but can't type.
A: Many hard of hearing people who can no longer use a conventional
telephone are using a TTY with the relay system in a manner known as
voice carry over or VCO. When used in this way, the TTY user is able to
read the response of the person at the other end of the line which is
typed by the relay operator. When it comes time for the TTY user to
respond, he or she can just speak the way they normally would and their
voice is then heard directly by the party at the other end. There are
VCO/TTY telephones available that are specially designed to do this.
Q: What about using a cell phone with my hearing aid?
A: There can be problems of interference when using a hearing aid
with a telephone coil with a digital cell phone however, there are
certain digital cell phones that do seem to work well with hearing aids
with t-switches. For those cell phones that do cause interference, there
are accessories available such as hearing aid compatible hands free
attachments or special neckloop or silhouette coils that permit the cell
phone to be used at some distance away from the hearing thus reducing or
eliminating this interference.
Q: My TV is not clear and my neighbors complain that I have it on too
loud. What can I do?
A: A very simple solution would be the use of a remote loudspeaker
(see Appendix 2) which serves to bring the sound closer to the listener
which will permit lower volume to be used and result in a clearer sound.
Another option would be the use of a TV radio which does the same thing
but will only work for transmitted channels numbers two through thirteen
and not for special cable channels. There are also special radio
frequency and infrared systems described below.
Q: I wear a hearing aid and have a particularly difficult time in
noise - what can I do?
A: Anything that will bring the speaker closer to your hearing aid
will significantly improve this situation and to this end, an external
microphone used with direct audio input (DAI) is highly recommended. DAI
allows you to plug external devices into your hearing aid but only if
your hearing aid has this feature.
Q: What if I am 25 feet away from the speaker?
A: Because a twenty five foot cord would be cumbersome. you could use
a personal FM system which consists of a microphone and small body worn
radio transmitter worn by the speaker and a small radio receiver that
you wear that can either be used with headphones or with your hearing
aid if your hearing aid has a telephone switch and/or direct audio
input. A personal FM system and external microphone do essentially the
same thing with the difference being that the FM system gives you a
wireless capability and is a lot more expensive.
Q: I have an especially hard time understanding what is being said at
the theater or at a movie. What can I do?
A: Wireless headsets (either infrared or FM) should be available at
theaters. You can also buy your own system to use at home with TV and
then take the receiver with you to the theater or movies but keep in
mind that these systems are not standardized and the headset you bring
with you may not be compatible with the system in the theater. In
addition to various listening systems, some movie theaters and some live
theater as well are presenting special performances or showings that are
captioned. Also keep in mind that at the movies, even though you may be
using very good quality equipment, spoken dialogue may be difficult to
understand because of background music and sound effects.
Q: I know that some TV programs are captioned so that I can read what
is being said but my TV set does not have this feature. What can I do?
A: If you own a TV that does not have a built-in decoder chip (a set
purchased prior to 1994), you can get an external decoder which will let
you see the captions. Please keep in mind that although external
decoders are still available, the easiest and most convenient thing to
do might be to just purchase a new TV set.
Q: I know that some people who wear hearing aids can use DAI and/or T
coils to connect to external devices but I use a cochlear implant - what
can I do?
A: There are special cords known as patch cords that are available
which will allow you to connect a telephone or other device directly to
your cochlear implant processor if it has an external audio input jack.
Q: Where can I see and try different ALDs?
A: There are many centers available. You can check with your local
SHHH chapter for local resources.
Q: Where can I purchase ALDs?
A: ALDs can be purchased from a number of sources including hearing
aid dealers. There are a number of companies that specialize in this
type of equipment most of whom have excellent catalogues. They may also
have very informative internet web sites through which devices may be
ordered on line.