TTY

Definition:

Teletypewriters. Text Telephone used in 7‐1‐1 call services. 7‐1‐1 is assigned nationwide for access to Telecom Relay

Services (TRS). TRS allows persons with a hearing or speech disability to use the telephone. These consumers use special

telephone devices known as a text telephone or a Telecommunications Device for the Deaf (TDD).

The 9‐1‐1 caller. Customers who use (rather than provide) telecommunications services; those who either originate or terminate telecommunications.

A feature that enables the PSAP attendant to transfer incoming 9‐1‐1 calls by manually obtaining dial tone through use of the telephone switch or...

Telecommunications Relay Service. 7‐1‐1 for the hearing impaired.

End Office. The telephone switching center that initiates a 9‐1‐1 call.

Glossary of Terms