5: Better Hearing: Electronic Devices
Aids, Cochlear Implants and
Assistive Listening Devices
of electronic devices -- for general use as well as specific
listening situations -- can help you hear better and interact
with others more effectively.
5a) Hearing Aids [View
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Cochlear Implants [View
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Assistive Listening Devices [View
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TV Headphone Systems
5a) Hearing Aids
reading about hearing aids, it may be helpful to understand
why people who seem to need them are reluctant to get them.
Start with this excellent article by Sam Trychin: "Why
Don't People Who Need Them Get Hearing Aids?"
following information on hearing aids is taken from National
Institutes of Health, National Institute for Deafness and other
Communication Disorders (NIDCD).
Can Hearing Aids Help?
basis of the hearing test results, the audiologist can determine
whether hearing aids will help. Hearing aids are particularly
useful in improving the hearing and speech comprehension of
people with sensorineural hearing loss. When choosing a hearing
aid, the audiologist will consider your hearing ability, work
and home activities, physical limitations, medical conditions,
and cosmetic preferences. For many people, cost is also an important
and your audiologist must decide whether one or two hearing
aids will be best for you. Wearing two hearing aids may help
balance sounds, improve your understanding of words in noisy
situations, and make it easier to locate the source of sounds.
Are the Different Kinds of Hearing Aids?
are several types of hearing aids. Each type offers different
advantages, depending on its design, levels of amplification,
and size. Before purchasing any hearing aid, ask whether it
has a warranty that will allow you to try it out. Most manufacturers
allow a 30- to 60-day trial period during which aids can be
returned for a refund.
There are four basic styles of hearing aids for people
with sensorineural hearing loss:
(ITE) hearing aids fit completely in the outer ear and
are used for mild to severe hearing loss. The case, which
holds the components, is made of hard plastic. ITE aids
can accommodate added technical mechanisms such as a telecoil,
a small magnetic coil contained in the hearing aid that
improves sound transmission during telephone calls. ITE
aids can be damaged by earwax and ear drainage, and their
small size can cause adjustment problems and feedback. They
are not usually worn by children because the casings need
to be replaced as the ear grows.
(BTE) hearing aids are worn behind the ear and are connected
to a plastic earmold that fits inside the outer ear. The
components are held in a case behind the ear. Sound travels
through the earmold into the ear. BTE aids are used by people
of all ages for mild to profound hearing loss. Poorly fitting
BTE earmolds may cause feedback, a whistle sound caused
by the fit of the hearing aid or by buildup of earwax or
- Canal Aids
fit into the ear canal and are available in two sizes. The
In-the-Canal (ITC) hearing aid is customized to fit the
size and shape of the ear canal and is used for mild or
moderately severe hearing loss. A Completely-in-Canal (CIC)
hearing aid is largely concealed in the ear canal and is
used for mild to moderately severe hearing loss. Because
of their small size, canal aids may be difficult for the
user to adjust and remove, and may not be able to hold additional
devices, such as a telecoil. Canal aids can also be damaged
by earwax and ear drainage. They are not typically recommended
- Body Aids
are used by people with profound hearing loss. The aid is
attached to a belt or a pocket and connected to the ear
by a wire. Because of its large size, it is able to incorporate
many signal processing options, but it is usually used only
when other types of aids cannot be used.
All Hearing Aids Work the Same Way?
The inside mechanisms of hearing aids vary among devices, even
if they are the same style. Three types of circuitry, or electronics,
The audiologist determines the volume and other specifications
you need in your hearing aid, and then a laboratory builds
the aid to meet those specifications. The audiologist retains
some flexibility to make adjustments. This type of circuitry
is generally the least expensive.
The audiologist uses a computer to program your hearing
aid. The circuitry of analog/programmable hearing aids will
accommodate more than one program or setting. If the aid
is equipped with a remote control device, the wearer can
change the program to accommodate a given listening environment.
Analog/programmable circuitry can be used in all types of
The audiologist programs the hearing aid with a computer
and can adjust the sound quality and response time on an
individual basis. Digital hearing aids use a microphone,
receiver, battery, and computer chip. Digital circuitry
provides the most flexibility for the audiologist to make
adjustments for the hearing aid. Digital circuitry can be
used in all types of hearing aids and is typically the most
Can I Expect From My Hearing Aids?
hearing aids successfully takes time and patience. Hearing aids
will not restore normal hearing or eliminate background noise.
Adjusting to a hearing aid is a gradual process that involves
learning to listen in a variety of environments and becoming
accustomed to hearing different sounds. Try to become familiar
with hearing aids under non-stressful circumstances a few hours
at a time.
are available to help users master new listening techniques
and develop skills to manage hearing loss. Contact your audiologist
for further information about programs that may suit your individual
Questions Should I Ask Before Buying Hearing Aids?
you buy a hearing aid, ask your audiologist these important
- Are there
any medical or surgical considerations or corrections for
my hearing loss?
design is best for my hearing loss?
- What is
the total cost of the hearing aid?
- Is there
a trial period to test the hearing aids? What fees are nonrefundable
if they are returned after the trial period?
- How long
is the warranty? Can it be extended?
the warranty cover future maintenance and repairs?
- Can the
audiologist make adjustments and provide servicing and minor
repairs? Will loaner aids be provided when repairs
- What instruction
does the audiologist provide?
- Can assistive
devices such as a telecoil be used with the hearing aids?
- What problems
might I experience while adjusting to my hearing aids?
- Become familiar
with your hearing aid. Your audiologist will teach you to
use and care for your hearing aids. Also, be sure to practice:
in and taking out the aids
right and left aids
the batteries with the audiologist present.
hearing aids may be uncomfortable. Ask the audiologist how
long you should wear your hearing aids during the adjustment
period. Also, ask how to test them in situations where you
have problems hearing, and how to adjust the volume and/or
program for sounds that are too loud or too soft.
- Your own voice
may sound too loud. This is called the occlusion effect
and is very common for new hearing aid users. Your audiologist
may or may not be able to correct this problem; however,
most people get used to it over time.
- Your hearing
aid may "whistle." When this happens, you are
experiencing feedback, which is caused by the fit of the
hearing aid or by the buildup of earwax or fluid. See your
audiologist for adjustments.
- You may hear
background noise. Keep in mind that a hearing aid does not
completely separate the sounds you want to hear from the
ones you do not want to hear, but there may also be a problem
with the hearing aid. Discuss this with your audiologist.
Are Some Tips for Taking Care of My Hearing Aids?
following suggestions will help you care for your hearing aids:
- · Keep
hearing aids away from heat and moisture.
- · Replace
dead batteries immediately.
- · Clean
hearing aids as instructed.
- · Do
not use hairspray or other hair care products while wearing
- · Turn
off hearing aids when they are not in use.
- · Keep
replacement batteries and small aids away from children
5b) Cochlear Implants
following information on cochlear implants is taken from the
National Institutes of Health, National Institute of Deafness
and other Communication Disorders (NIDCD)
Is a Cochlear Implant?
implant is a small, complex electronic device that can help
to provide a sense of sound to a person who is profoundly deaf
or severely hard of hearing. The implant is surgically placed
under the skin behind the ear. An implant has four basic parts:
- ·A microphone,
which picks up sound from the environment;
- A speech processor,
which selects and arranges sounds picked up by the microphone;
- A transmitter
and receiver/stimulator, which receive signals from the
speech processor and convert them into electric impulses;
- And electrodes,
which collect the impulses from the stimulator and send
them to the brain.
does not restore or create normal hearing. Instead, under the
appropriate conditions, it can give a deaf person a useful auditory
understanding of the environment and help him or her to understand
Does a Cochlear Implant Work?
implant is very different from a hearing aid. Hearing aids amplify
sound. Cochlear implants compensate for damaged or non-working
parts of the inner ear. When hearing is functioning normally,
complicated parts of the inner ear convert sound waves in the
air into electrical impulses. These impulses are then sent to
the brain, where a hearing person recognizes them as sound.
A cochlear implant works in a similar manner. It electronically
finds useful sounds and then sends them to the brain. Hearing
through an implant may sound different from normal hearing,
but it allows many people to communicate fully with oral communication
in person and over the phone.
Gets Cochlear Implants?
types of deaf and severely hard of hearing people choose cochlear
implants. Both children and adults can be candidates for implants.
Approximately 70,000 people worldwide have received implants.
In the United States, some 21,000 people have implants; about
half of these are adults and half are children.
who have lost all or most of their hearing later in life can
often benefit from cochlear implants. These older candidates
can often associate the sounds made through an implant with
sounds they remember. This may help them to understand speech
without visual cues or systems such as lipreading or sign language.
children can also be candidates for implants. Cochlear implants,
coupled with intensive post-implantation therapy, can help young
children to acquire speech, language, developmental, and social
skills. The best age for implantation is still being debated,
but most children who receive implants are between 2 and 6 years
old. Earlier implantation seems to perform better.
Does Someone Receive a Cochlear Implant?
implant is a surgical procedure. The decision to receive an
implant should involve discussions with many medical specialists
and an experienced surgeon. The process is expensive. Some may
choose not to have a cochlear implant for a variety of personal
reasons. Also, though surgical implantation is almost always
safe, complications are a risk factor, just as with any kind
of surgery. An additional consideration is learning to interpret
the sounds created by an implant. This process takes time and
practice. Speech-language pathologists and audiologists are
the professionals frequently involved in this learning process.
Not everyone performs at the same level with a cochlear implant.
Prior to implantation, all of these factors need to be discussed.
Does the Future Hold for Cochlear Implants?
technology behind cochlear implants is changing rapidly. With
advancements in technology and continued follow-up research
with people who have already received implants, researchers
are evaluating new opportunities and additional possible candidates
for cochlear implants.
5c) Assistive Listening Devices (ALD's):
Help for real-world listening situations
are electronic devices, other than hearing aids, that help you
hear better in tough listening situations.
ALD's help you hear more clearly while others alert you to something
that requires your attention. Amplification Systems
help you hear more clearly. Examples include the headsets worn
in movie theaters and houses of worship, and amplified telephones.
Alert (Notification) Systems notify you when some event
occurs such as the ringing of the doorbell or phone.
section consists of the following subsections:
- large area
- TV listening
devices enhance and amplify the sound, and bring it directly
to your ears. Like
hearing aids, ALD's make sounds louder but unlike most hearing
aids which amplify all sounds, ALD's amplify the sounds you
want to hear, while bypassing the sounds you don't
want to hear such as chairs scraping, people talking, and air
best way to hear better is to get closer to the source of
that's what ALD's do. They are placed at or near the sounds
you want to hear.
what assistive listening devices can do for you:
- Eliminate or
reduce background noise
- Overcome the
problem of distance, putting the speaker right next to you
- Increase the
clarity of the words
- Provide clearer
sound in noisy environments than hearing aids.
they are easy to use, require no custom fittings, and are far
less expensive than most hearing aids.
of amplification devices and systems
1. Amplified Phones
phones can strengthen the incoming signal more than thirty times
(up to 50 decibels louder). Most phones can also boost the higher
frequencies, which is where most hearing loss occurs. This results
in greater speech intelligibility because the consonants become
phones contain large buttons for the visually impaired, extra-loud
ringers with visual indicators (flashing lights), and speed
dial buttons. Some will even amplify the outgoing voice
in case the hard-of-hearing person also has a soft or faint
phones are hearing aid compatible. To understand what this really
means, we need to shed some light on the mysterious "T-coil."
T-coil stands for telephone coil. It is a tiny coil of wire
that fits in the hearing aid. About 30% of the hearing aids
in this country contain T-coils. (You have one if your switch
has a "T" setting.) It's a great thing to have because
it enhances the clarity of phone conversations and can also
help out in certain public settings. (See "Induction Loop
how it works. When the switch is set to "T", the microphone
is turned off. It's a principle of physics that whenever current
runs through a wire, it generates a magnetic field around the
wire. So when current runs through the small speaker in your
telephone handset it generates a magnetic field that, in turn,
generates (induces) a current in the T-coil of the hearing aid.
The signal, which has bypassed the microphone in the hearing
aid, is amplified and passed directly into the ear. The signal
is very clear and since the microphone is not being used, there
is no feedback and no pickup of room noise.
2. Large-Area Amplification Systems
auditorium-style systems are designed to help multiple users
hear better in large area situations such as:
- houses of worship
- movie theaters
- lecture halls
- outdoor gatherings
(FM system only)
large area systems are wireless. In
wireless systems, the sound is picked up from the person speaking
and is transmitted through the air as invisible electromagnetic
waves where it is received, amplified, and delivered directly
to the listener's ears.
user is free to move around since he is not wired to the sound
source. There is no restriction to the number of people receiving
the signal as long as they are within range. In large facilities
you can easily have more than a dozen people receiving the amplified
are compact, about the size of a "Walkman" or a deck
of cards, while transmitters vary in size. Transmitters for
large areas are about the size of a toaster oven. Personal systems
and TV listening systems use much smaller transmitters.
are three types of systems, depending on the type of wave that
is generated: FM radiowaves, infrared lightwaves, and magnetic
The FM system uses the same type of FM radio
wave that you can pick up on a regular radio. It is probably
the most common and versatile system in use today.
consists of a small transmitter which acts like a miniature
radio station, and a number of small portable receivers. The
receivers and transmitter are all tuned to the same frequency
transmitter usually sits on the stage or is connected to the
sound system in the sound room. The signal can reach people
more than 300 feet away.
systems can be used in adjoining rooms without interfering
with one another if the transmitters and receivers in each
room are set to their own unique frequency.
- excellent fidelity
- portable and
easy to set up and use
- low cost
- works equally
well indoors and out
- large area
- penetrates walls
and other obstacles.
- may be subject
to outside interference (police, fire, pagers)
- spillover into
adjacent areas permit eavesdropping
Infrared Light system uses the same type of signal
as your TV's remote control. These invisible light waves fall
just below the visible spectrum. The receiver, often a headphone,
has a little "window" that catches the light waves
and converts them back into sound. This window must be accessible
to the light. It can not be covered up or kept out of sight
(as can the FM receiver).
area systems are commonly used in movie theaters. Lightwaves
do not penetrate walls so transmitters in adjoining theaters
will not interfere with one another. Large area infrared light
systems are more difficult to set up than other systems. The
transmitters must be set at the correct angle and may require
more than one, so the system can be more expensive as well.
- Light doesn't
penetrate walls (no spillover)
- excellent fidelity
- not subject
to interference from radio waves.
and receivers must be unobstructed
- can be used
- high intensity
lights and direct sunlight can interfere with signal
- systems for
large areas are more expensive and more difficult to set
c) The Magnetic or Induction Loop system operates
on a basic principle of physics that when electricity runs
through a wire, it creates a magnetic field. In the induction
loop system, a wire is laid around the perimeter of a room
or activity area (like a museum exhibit). The transmitter,
instead of sending the sound directly through the air as invisible
waves, first pumps it through the wire, creating a magnetic
field that fills the area within the perimeter of the wire.
This signal can be picked up by a hearing aid with a T-coil
or by a portable receiver.
set up, it is ideal for anyone with a T-coil hearing aid.
No additional receiver is necessary. Otherwise, like the other
systems, a receiver is required.
receiver necessary for T-coil wearers
pickup areas can be precisely defined.
to electrical interference from power sources and electrical
high installation costs
areas may exist within loop.
3. Personal Amplification Systems
systems are used in the home, in the restaurant, the car and
the classroom, as well as outdoors. They are ideal for one-on-one
conversations, small group discussions, and teacher/student
interactions. There are two types of personal systems commonly
in use: the Personal FM (wireless) and the Personal
The Personal FM system operates
like the FM system described above, only it is much more portable.
It is perfect for one-on-one communication and is typically
used in a classroom. The teacher wears a lapel mike wired
to a pocket-sized transmitter that is carried on his person.
can move about freely and everything he says is transmitted
through the air and heard clearly by students equipped with
receivers. (See above for discussion of how an FM system works.)
The student's receiver usually comes equipped with its own
microphone so, if he wishes, he can hear other students in
the immediate area.
The Personal Hardwired system. Unlike
wireless ALD's which make use of radio frequencies, infrared
lightwaves, or a magnetic field to transmit the sound, the
hardwired device uses a direct electrical connection. It is
a self-contained unit the size of a "Walkman" to
which you can connect a headset, earbud or neckloop. The unit
is placed closer to the person or group speaking and can usually
pick them up quite clearly.
4. TV Listening Systems
systems are wireless systems that transmit the sound from a
TV (or other sound source such as a stereo or computer) to a
receiver. A small transmitter sits on top of the TV and gathers
the sound from either a small mi
crophone placed over the speaker or from a cable plugged into
the "audio out" socket on the back of the TV. Like
other wireless systems, the sound is converted to radio waves,
infrared light, or magnetic energy, transmitted through the
air, and picked up by the receiver.
headset has its own volume control and is independent from that
of the TV's
speakers. The headset can be turned up loudly while the TV's
volume is set at a comfortable level for others in the room,
or even turned all the way down.
systems have different advantages. The FM listening system permits
you to walk into another room or go outside and still hear the
sound but it is subject to outside interference and interference
from other nearby TV systems. The infrared light system, on
the other hand, does not penetrate walls but does allow you
to have more than one system operating in the house without
risk of interference.
5. Coupling Devices
coupling device, such as a headphone, takes the signal from
the receiver and brings it directly to the ear. There are several
options, depending on personal preference and type of hearing
aid, if any.
HEARING AID: Earbud or headset.
AID WITH T-COIL: Neckloop or silhouettes. These
work by magnetic induction. The neckloop or silhouettes are
plugged into the receiver. The neckloop is worn around the neck,
like a necklace. (It can be worn under a shirt or blouse.) The
silhouettes rest behind the ear. When electricity runs through
them, they generate a magnetic field which is transmitted through
the air to the T-coil in the hearing aid and into the ear. The
advantage here is that there is no wire going from the receiver
to the ear.
AID WITHOUT T-COIL: Headset, but feedback is a possibility
unless the hearing aid is the in-the-canal type. You may need
to remove the hearing aid.
BTE (BEHIND-THE-EAR) HEARING AID: Most BTE hearing aids
have a T-coil so they can use the neckloop or silhouettes.
Other options include the DAI cord and the FM receiver
DAI (Direct Audio Input) cord is a wire that runs from the receiver
to a boot attached to the BTE hearing aid. (A boot is
a little adapter that snaps into the bottom of the hearing aid
to give the DAI cord something to plug into. The cord is too
big to plug directly into the hearing aid.) This can produce
a very powerful signal because the amplified signal from the
receiver is further amplified by the hearing aid. The DAI cord
can also connect directly to computers, tape recorders, and
other audio sources.
FM receiver boot snaps onto the BTE and can receive signals
directly from FM transmitters. No other receiver is necessary.
This is the ultimate in portability. This device should be fitted
by an audiologist.
IMPLANTS: A DAI cord (Direct Audio Input) runs from
the receiving device to the speech processor.
B. Alert Systems
ALD's convert sounds you need to hear into visual stimuli
or vibratory stimuli, or they may simply amplify the sound so
it can be heard. Some examples will give you an idea of how
in various rooms can be plugged into special receivers so that
whenever the phone rings, all the lamps flash. In this case,
the signal is transmitted through the house wiring. You can
place a small doorbell/transmitter at the front door. When somebody
rings the bell, the transmitter sends an FM radio signal to
receivers in various rooms which, again, cause lamps to flash
on and off.
of flashing lamps, you could have your wrist watch or beltclip
receiver vibrate. If you can't hear the alarm clock, you could
put a vibrating bedshaker under the mattress or pillow, or use
a clock with a built-in strobe light.
want to hear the oven timer go off or be sure the baby is o.k.,
plug in a transmitter with a built-in microphone into a nearby
outlet. When it "hears" a sound, it will send the
signal through the house wiring to all receivers.
the ultimate in effective low-tech, try the door-knock signaler.
Simply hang it on the inside of your motel or dorm door. When
someone knocks, a bright light goes off.
are also base stations (master consoles) available which receive
signals from different types of transmitters and indicate, via
lighted icon, which event is occurring.
6: Action Steps
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