Dont waste your money on a TTY ever again! myTTY is a Windows computer program that can make your computer perform like a sophisticated TTY with many more features (e.g., phonebook, answer machine, caller ID, descramble, customized fonts...
Deaf people and others who cannot hear or speak over the telephone use equipment called a teletypewriter (TTY) instead. TTYs allow individuals to type back and forth to each other. TTYs use a code called Baudot to transmit signals over telephone lines, unlike computers, which use ASCII.