ASSISTIVE LISTENING DEVICES
(ALDs)
Benefits of Using Assistive Listening Devices
Many students who use hearing aids effectively in quiet environments have a difficult time hearing
information presented in large college classrooms. Others may have difficulty hearing the instructor
because of central auditory processing problems or attentional difficulties. In the classroom, the
instructor's voice must carry a long distance and is often competing with background noise or poor
acoustics. Most assistive listening devices or ALD’s use a microphone/transmitter positioned 3-5”
from the instructor's mouth to send the speaker’s voice directly to the receiver worn by the student.
A distinct advantage of an ALD when compared to personal hearing aids is the input microphone is close to
the instructor's mouth, which allows a constant volume level to be maintained, regardless of the distance
between the instructor and the student. The instructor's voice is also heard clearly in spite of competing
noises and poor acoustics.
Frequency Modulated (FM) Systems
An FM system is a common ALD. It is a wireless, battery-operated device that uses radio signals to
send sound from a transmitter to a receiver. With most FM systems, the instructor wears a lavalier microphone
connected to a small transmitter clipped to the belt. The student has the receiver and uses an ear bud in
his/her ear or a wire that plugs into the hearing aid.
Suggestions for Classroom Use
- Face the student when speaking. Even though the student can hear at greater
distances with the ALD, she/he may also rely heavily on visual cues to aid
understanding.
- Arrange for the student to sit close to the instructor and blackboard.
- Allow only one person to speak at a time during large class discussions. Repeating the
questions/comments provides the student access to all the information.
- For small groups, such as seminar classes, a conference microphone on loan from DSS is placed
in the center of the table, and picks up the voices of everyone seated at the table.