Assistive Listening Systems 1557delay can be very distracting to those with less than
profound hearing impairments.
Battery replacement and earpiece sanitizing are the
principal maintenance problems with all systems for the
assisted listening devices. Batteries may last up to one
year, although that seems an uncommonly long life if
the receivers are being used often. The infrared
receivers have rechargeable batteries, which should be
recharged after each use. Earpieces are most commonly
sanitized by replacing the plastic ear tips or by using
replaceable foam balls.
Most theaters and concert halls provide receivers to
their patrons for no charge or for a small fee to cover the
cost of handling, batteries, and sanitizing. Some organi-
zations have been successful in selling receivers to
regular patrons, especially in communities where
several theaters and churches use the same technology.
References
- M. C. Martin, “Power Requirements for Inductive Loops,” Royal National Institute for the Deaf, London, Eng-
land. - S. C. Dalsgaard, “Field Distribution Inside Rectangular Induction Loops,” State Hearing Centers, Research Lab-
oratory for Technical Audiology, University Hospital, Odente, Denmark. - D. Bosman and L. J. M. Joosten, “A New Approach to a Space-Confined Magnetic Loop Induction System.”
IEEE Transactions on Audio, May/June 1965.
Bibliography
K. Borrild, “The Induction Loop and Its Possibilities,” The State Boarding School for Hard of Hearing and Deaf,
Frederica, Denmark.
E. deBoer, C. Kruidenier, and K. W. Kortschot, “On Communication Systems in Schools for the Hard-of-Hearing,”
Acustica, vol. 19, no. 3, 1967–1968.
RNID Scientific and Technical Department, Installing a Loop System. “Hearing,” Royal National Institute for the
Deaf, October 1977.
Figure 42-19. A wireless IR system receiver under the head
multichannel headset. Courtesy Sennheiser Electronic
Corporation.