TTY (Teletypewriter)


A device that enables phone communication through typed messages for people who can't or choose not to communicate verbally, typically used by individuals who are deaf or hard of hearing, or who have a speech impairment or disability.


A scientist who was deaf, Robert Weitbrecht, invented the teletypewriter (TTY) in the 1960s, according to the National Association of the Deaf.

Initially, calls using this technology needed a TTY on both ends, which meant there was limited telephone communication between those who were deaf or hard of hearing and those using telephones without a TTY until the onset of TTY relay services. Relay services allow communication between TTY users and someone communicating by speaking and hearing with the telephone.

Relay services were increasingly but not consistently available until the passage of the Americans with Disabilities Act (ADA), which required by law nationwide relay services and established a free nationwide relay network to handle voice-to-TTY and TTY-to-voice calls, according to an ADA Business Brief.