[Tips & Tutorials] What is TTY mode in Call Settings stands for?? Hi guys! Here i am gonna explain about TTY mode in call settings.. Cell phones have so many features, it can be tricky to figure out what they all do. One of the more mysterious options is the TTY mode. The TTY abbreviation stands for teletypewriter, a device that allows deaf or hearing-impaired individuals to communicate via the telephone by typing text messages. Cell phones with a TTY mode are compatible with this technology and perform the same service after they're connected to a TTY device. History While the telephone revolutionized communication following its invention during the late 1800s, deaf individuals could not benefit from the technology until Robert Weitbrecht invented the teletypewriter in the 1960s. The original TTY machines used an acoustic coupler to hold the telephone handset receiver and recycled teletype machines to tr...