In the past, many hearing impaired individuals use two types of equipment to communicate through the telephone. Those included a hearing aid and/or an amplified handset. The hearing aid can be acoustically or inductively coupled to the telephone. In acoustic coupling, the telephone handset is held near the microphone of the hearing aid. Sufficient loudness is achieved by adjusting the gain of the hearing aid. In inductive coupling, the receiver in the telephone handset is placed next to the body of the hearing aid. A voltage is induced in a small coil (telecoil) in the hearing aid when it is placed in the magnetic field which may emanate from the telephone receiver. This voltage is the signal that is amplified by the hearing aid for the user. This inductive coupling method usually provides the user with adequate volume without the annoying acoustic feedback that can occur with acoustic coupling. Also, with the telecoil setting, the microphone of the aid can be turned off so the user does not hear any noise in the room while they are using the phone. Some hearing aids can be programmed so the microphones are off completely or the volumes of the microphones are reduced.
The capability to inductively couple a hearing aid to a telephone arose quite spontaneously. It was never possible with other than Bell System phones. Bell System neither advertised the presence of the magnetic field nor encouraged hearing aid manufactures to depend on it. However, hearing aid manufacturers realized the potential value of the stray magnetic field and designed telecoils which could be placed in hearing aids to detect the magnetic field and then amplify it.
So what all this mean for people living in northern Indiana or more specifically people in the Fort Wayne area in the past? In this area, our telephone service was supplied by GTE. GTE phone receivers were manufactured by Automatic Electric and they did not produce a sufficient magnetic field. People in southern Indiana were served by Bell Telephone. Bell’s telephone receivers were manufactured by Western Electric and those receivers produced the needed magnetic field. People living in the Indianapolis area were used to using the telecoil in their hearing aids. If those people visited friends in Fort Wayne and tried to use the telecoil of their aid, it would not work. Often they thought their hearing aid telecoil setting was broken and they would become quite angry! However, the real reason the telecoil setting would not work was that the GTE phone did not produce an adequate magnetic field to be detected by their telecoil. Individuals in Fort Wayne could never use the telecoil in their hearing aids unless they purchased a special strap-on adapter or tried purchasing a different telephone.
As of August 16, 1989, all telephones manufactured or imported for use in the U.S. have been required to be hearing aid compatible. Cordless telephones manufactured or imported for use in the U.S. have also been required to be hearing aid compatible since August 16, 1991. Employers must ensure that telephones, including headsets, made available to employees with hearing disabilities for the performance of their duties are hearing aid compatible. (Please note that a HAC phone may not be the accommodation a deaf person needs to use the phone – some may need text telephones, for example, and may be entitled to other accommodations under Title I of the Americans with Disabilities Act).
For adequate telephone communication, be sure to ask your audiologist about ordering hearing aids that have telecoils. They can significantly improve your ability to communicate on the phone. If you have telecoils in your hearing aids, you may also want to use them in facilities that have installed inductive loop systems. If you are in a room with a loop system, simply switch your hearing aid to the telecoil setting. You will hear the speaker as if they are speaking directly into your ear! The signal to noise ratio will be the best you can ever get. Some newer hearing aids are Bluetooth compatible and can provide another alternative to the telecoil technology.