Access for 9-1-1 and Telephone Emergency Services

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.