Proper Use of Telecoils: It's as easy as 1,2,3...4!
by Larry Revit, hearing scientist
Since many of you are hearing-aid dispensers, and since many others have
clients that are hearing aid dispensers, here's some information that can
be passed on to the end useres: those hearing-aid wearers who use inductive
telephone pickups, or "telecoils."
Ususally, instructions for using telecoils call for three steps:
- Move the switch on the hearing aid to "T".
- Turn up the gain (volume) control.
- Move the telephone receiver (earphone) around the hearing aid until the loudest signal is heard.
If the telephone is far away from any stray magnetic fields, that set of instructions is fine. But power wires, fluorescent lights, electric motors, video monitors, etc., all emit electromagnetism which can seriously interfere with telecoil use. Such interference often causes loud humming or buzzing in the hearing aid when the instrument is set to "T".
Fortunately, electromagnetic fields are directional, and the proper orientation of the telecoil within such fields can minimize the detrimental effects. Just as moving the telephone receiver around the hearing aid can minimize the desired coupling of the telephone's magnetic signal to the telecoil pickup in the hearing aid, moving the hearing aid around in a stray magnetic field can minimize the undesired magnetic coupling of the hum or buzz from extraneous environmental sources.
Therefore, instructions for the use of telecoils should contain four steps:
- Move the switch on the hearing aid to "T".
- Turn up the gain (volume) control.
- If there is a hum or buzz in the hearing aid, move your head up and down and side to side until the buzz is the most quiet.
- Move the telephone receiver (earphone) around the hearing aid until the loudest signal is heard.
As a hearing-aid wearer, myself, I almost always have to use the above four-step process. Often, people pass me in telephone booths with questioning stares... wondering why I'm standing with my head tilted over to the side. Sometimes it's inconvenient, but that tilt of the head can make the difference between disability and ability in using the telephone.