Access for 9-1-1 and Telephone Emergency Services

D. Procedures for Handling TTY Calls

In addition to proper equipment, direct, equal access for TTY calls requires that PSAPs use effective procedures for recognizing and responding to TTY calls.

Recognizing TTY Calls/Treating Silent, Open Lines as Potential TTY Calls

All call takers must be able to recognize and handle TTY calls properly. There are three types of TTY calls a call taker may receive. Some TTYs emit a recorded spoken announcement to the call taker that a TTY call is being placed, such as "HEARING IMPAIRED CALLER. USE TTY." Other times, TTY callers may press TTY keys to emit audible tones and more quickly notify the call taker that a TTY call is being placed. Most often, however, a person using a TTY will make a call that is perceived by the call taker as a silent, open line call. This is because the caller's equipment does not recognize that the call has been answered until the call taker sends a TTY response.

The only way for PSAPs to properly identify all TTY calls is for call takers to recognize TTY tones and to query every silent, open line call with a TTY to determine if it is a TTY call after it has been queried by voice.

Requiring Callers Using TTYs to Press a Key

In the past, some PSAPs have required callers using TTYs to press the space bar or other keys after they call, to emit tones and notify call takers that it is a TTY call. This requirement violates the ADA. Requiring TTY callers to press keys repeatedly until recognized is unfamiliar to most TTY callers, and callers cannot be relied on to perform such unfamiliar tasks, especially in emergency situations. Further, in many emergency situations there may not be time or opportunity to press keys repeatedly until recognized.

ILLUSTRATION: A 9-1-1 call taker answers a call, responds with a standard spoken greeting, and expects to hear a spoken response. If the call taker receives a silent, open line, the call taker should query the line verbally a second time, and then query the line using a TTY to determine if the call is from a TTY user.

TTY Detection Equipment

Q: If a PSAP uses TTY detection equipment, does it still have to query every silent call with a TTY?

A: Yes. Some PSAPs have installed equipment that detects TTY calls and produces a voice announcement to the call taker that a TTY call has come in. TTY detection equipment, however, only recognizes TTY calls that transmit tones, such as when callers press keys to emit tones. This equipment will not recognize TTY calls when the caller does not emit tones and instead waits for a TTY response before transmitting. Thus, TTY detection equipment does not eliminate the need for call takers to query every silent line with a TTY.

Dispatching Police to Origin of Silent Calls

It is not sufficient merely to dispatch police to the origins of all silent, open lines, in lieu of querying the lines with a TTY. Precious time may be lost by sending the police if the caller needs another type of response, such as fire or emergency medical services. All silent, open lines must be queried with a TTY to assess the basis for the call and to dispatch the appropriate emergency equipment and personnel.

Conducting TTY Calls

After TTY calls are recognized, call takers must effectively communicate with callers during the calls. Effective communication by TTY will require call takers to be familiar with the use of TTY equipment and TTY protocols.