User manual

Guide to FM Systems
6::
Using FM systems in difficult
listening environments
Ideally, FM systems should be used in difficult or complex listening situations. A
listening situation is considered difficult when (1) the signal (e.g. a teacher’s voice)
is very far away from the listener, (2) the background noise is very loud and additional
sounds make it difficult to hear the signal (e.g. in a classroom), or (3) in reverberant
rooms where the echo distorts the signal (e.g. in auditoriums).
Indoor listening environments
At home, rooms such as the kitchen, bathroom, hallway, laundry, basement, etc. are
characterized by particularly high reverberation levels due to the sparse use of sound-
reducing materials such as carpets, curtains, etc. Large, smooth surfaces lead to
multiple reflections of sound waves. A table without a tablecloth, therefore, may also
create a difficult listening situation for a hearing-impaired individual by reflecting
sound. A golden rule for improving listening situations is to use as many sound-
reducing materials as possible in all rooms. Background noise is another condition in
the home that can adversely affect a listening environment. Sounds from a radio, for
example, may complicate a listening situation and should be turned off when
possible. When background noise is unavoidable in the home, an FM system can be
of considerable benefit.
Group situations, restaurants, etc.
In group situations, background noise is considerably louder than in individual
conversations. Low level conversation, laughter, scraping of chairs and clinking of
dishes all add noise to the environment. An FM system can be of assistance in this
situation as the listener can position the FM microphone near the desired sound
source, thereby enhancing the signal and effectively reducing the effect of
background noise.
Many listeners have great difficulty hearing speech in restaurants where there is a
great deal of background noise. Some solutions include placing the FM microphone
on the speaker’s collar or hanging it from a light fixture above the table. Group
members should be aware of the difficulties such environments impose on a person
with a hearing loss, and limit the conversation to one speaker at a time.
Celebrations, parties
Noise levels at parties and other celebrations are usually very high. Music,
conversation and laughter are often so loud that even normally hearing people have
to raise their voices in order to be heard. As this happens, background noise levels
increase further. Speaking directly into the microphone of the FM system is very
helpful in such situations.
Another tool ideal for such difficult environments is the TeleMic system. The
integrated external microphone allows the TeleMic to be used as a “tie-clip”