| Assistive
Listening Devices (ALDs) can dramatically improve communication
in difficult listening situations |
Thanks to modern hearing instrument technology, people with hearing
loss are now able to hear and understand clearly in many everyday
situations. Nevertheless, Assistive Listening Devices (ALDs) can
provide additional benefits to many hearing impaired individuals.
| When can Assistive Listening
Devices be beneficial? |
Generally speaking, you should consider using an ALD if situational
barriers to communication prevent you from understanding others.
The following three factors have a negative impact on the quality of the
signal received by your hearing instruments:
- Noisy backgrounds, e.g. at public events, in restaurants, while
driving
- Distance from the person speaking, e.g. conferences or guided
tours
- Places with a high level of reverberation, e.g. large halls
Many of the things we enjoy most in life take place in environments
where even people with good hearing often have difficulty understanding
: social and business occasions, lectures, cars, public transport,
sporting events, religious ceremonies, or listening to guided tours.
A microphone is placed close to the sound source you wish to hear :
e.g. your conversation partner in the car, the speaker at a university
lecture, the TV set, etc. The speech signal is transmitted
directly to your hearing instruments.
| ...and how you connect them
to your hearing instruments |
To connect an ALD, your hearing instrument must have an audio input
facility. This is a built-in connection which enables the signal
to be transmitted directly into your hearing instrument without being
picked up first by its microphone. Audio-input is commonly
available only in Behind-the-ear (BTE) intruments.
 |
The audio shoe is attached to the
hearing instrument, where it serves as a bridge between the
hearing instrument and the ALD. Most ALDs are connected to the
audio shoe by a cable. There are also some which have a
radio connectionto the audio shoe, and require no cable. |
| Different types of ALDs at a
glance |
| 1.
Wireless communication systems |
Essentially, wireless communication systems consist of two components
: a microphone with a transmitter and a receiver connected to a hearing
instrument. The speaker's voice is conveyed as a radio signal -
i.e. without a cable connection from the transmitter to the
receiver. These systems are extremely convenient to use, have a
long range and are suitable for indoor and outdoor use.
|
|
| Microphone/transmitter units |
 |
Type A : The microphone and transmitter are
worn by the person you wish to hear. The microphone is
connected to the transmitter via a cable. This unit is
particularly suitable for lectures, school and guided tours. |
| Type B : The transmitter and microphone are
housed in a single unit. This device can be held by the
hearing instrument user, who directs it towards the person he/she
is listening to. |
 |
| Receivers and hearing
instrument connection |
 |
Type A : The receiver is worn by the hearing
instrument user and is connected to the hearing instrument with a
cable. |
| This system, where the speaker wears the
transmitter and the hearing instrument user the receiver, is ideal
for lectures, semianars, conferences, noisy work environments,
etc. |
| Type B : In this tiny, ultralight system, the
receiver is built into the audio shoe, eliminating the cable
between receiver and hearing instrument. |
 |
| There are unlimited uses for this system : social
and business occasions, noisy working environments, classrooms and
lecture halls, churches, guided tours, sporting events, radio and
TV broadcasts, private and public transport, at the theater,
concerts... |
| 2.
Communication systems with cable connections |
 |
Hand-held microphone : The fact that it can
be pointed easily in the desired direction makes the hand-held
microphone ideal for direct communication |
| between speaker and listener. It is
particularly helpful in restaurants, vehicles, discussions, etc. |
| Conference microphone : The conference
microphone is useful for participating in group
conversations. It can be positioned on the table and |
 |
| directed towards the person speaking or other
specific sound sources. |
 |
External telephone coil : Like the coil built
into the hearing instrument itself, the external telephone coil
functions as an inductive pick-up system. |
| It provides additional amplification for telephone
calls or in public buildings equipped with loop systems (churches,
theaters, lecture and concert halls, etc.), if the hearing
instrument's built-in coil has insufficient boost. |
| Telephone coupler : A telephone coupler
boosts the signal from any telephone and consists of an acoustic
microphone with its own volume |
 |
| control, independent of the hearing
instrument. Telephone couplers can be used also with radios
and televisions, tape recorders and CD players. |
 |
TV/stereo-volume control : The volume control
is connected directly to your television or stereo set and your
hearing intruments. It enables optimum |
| transmission and adjustment of the volume
independently of the TV or stereo system. |
|
