Signaling and Text Display Systems

People with hearing loss can benefit from signaling and substitution systems, which convert sound or key strokes into another mode, such as text or flashing lights.

Signaling and Warning Systems

Lights can be used to signal everything from the phone ringing to the doorbell. There are different ways of hooking a light into the telephone line; for example, when the phone rings, a light flashes. It can be set up to flash in the living room, even if the phone is located somewhere else, such as the kitchen. A light also can be hooked into a small transmitter in the doorbell, with a receiver triggering a light or a loud buzz in each room of the house, which works through the house wires. Even when you are staying somewhere besides your house, such as at a hotel, you can ask for a doorknocker light, which is placed on the inside of the door and lights when someone is knocking.

A visual smoke alarm is a must if you have hearing loss, as the sound signal generated by smoke alarms may not be sufficient to wake you up. Some alarms come with both visual and audible signals. They are as simple to install as the ordinary sound alarms. These also can be requested when staying in a hotel. Unfortunately, some of the visual smoke alarms in the hotels are not tied into the central fire alarm system. Some hotel chains are more sensitive to these problems than others, so the status of the visual smoke alarm should be verified whenever making reservations and when checking into a hotel.

There also are baby monitors that use a flashing light. An intercom can be placed next to the crib of an infant or bed of a mobility-impaired person. A light-flashing receiver is then put in the parent or caregiver's room.

To integrate all of these systems -- telephone, doorbell, fire alarm, baby monitor -- there are base stations that convert each sensor into a different stimulus, such as one, two or three flashes. In addition, the receivers can be worn on the wrist and deliver a vibratory or a light signal.

An all weather microphone on the rear window or inside the trunk of your car can be installed to trigger warning lights from an indicator resting on the dashboard when an emergency vehicle is approaching with its siren on. The equipment and installation of this device can be reimbursed in any new GM, Ford or Chrysler vehicle. This program is called Emergency Alert Response Systems (EARS).

Another automotive device, although not free, is called a signal indicator and it lets the individual know whenever the turn indicator has been left on for longer than 15 seconds, without the brakes being engaged. A dash light will flash and a buzzer gets louder and louder the longer the turn indicator stays on.

Text Display Systems


The classic text display system is the teletype system (TTY). About 35 years ago, a deaf physicist developed a way to connect TTYs through a telephone modem. This opened up the world of telecommunication to deaf people. This is the same device that is sometimes called text telephone (TT) or telephone devices for the deaf (TDD).

A TTY system looks a bit like a typewriter with a built-in acoustic coupler for the telephone. A direct electrical connection to the telephone line is used for permanent hookups. TTYs come in all shapes and sizes, the smallest ones are about the size of a notebook. If a phone call is received, a light will flash to signal you. The receiver will answer the phone by typing in, for example, "hello, this is mark, ga" ("ga" stand for for "go ahead"). The sender then types a message back to the receiver, which they can either read on a small screen or on a paper copy. To communicate this way, both the sender and the receiver must have a TTY.

If the person you want to talk you does not have a TTY, you can use a telephone relay service. This is a national program, available in all states through an 800 number. The number is listed in the first pages of every telephone book. First you must call the relay service and tell the relay operator, who serves as a communication assistant (CA), that you want to make a voice carry over (VCO) telephone call to particular number. The CA will call the number and tell the person that you are calling. The CA will let you know, by typing, that the connection has been made. Then, you speak directly to your party. Your party, in turn, talks to you through the CA, who types the messages that you read on your TTY or special VCO telephone. It works the other way too. The normally hearing person can call you through the relay operator. So even if you can't hear a sound, telephone communication is still possible. Today, many deaf people also use their computers and the Internet for real-time communication, and it's likely that this form of communication will increase exponentially in future years.

TV Closed Captioning

Television sets manufactured after 1994 usually include a chip that provides access to captioning. Click on the menu on the remote or directly on the TV set and cycle through the options until you see the closed captioning command. Routinely, it is turned "off" initially. Turn it "on." When you do so, you'll see a written version of the speech and other information about sounds occurring appear on the screen. Not all programs are captioned, but more and more will be as the regulations of the new law on telecommunications come into force. Separate decoder units are available for TV sets that do not have a closed captioned feature.


Reviewed by health care specialists at UCSF Medical Center.

This information is for educational purposes only and is not intended to replace the advice of your doctor or health care provider. We encourage you to discuss with your doctor any questions or concerns you may have.

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2330 Post St., Suite 270, Campus Box 0340
San Francisco, CA 94115
Phone: (415) 353-2101
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