a tool utilized by people with hearing loss or speech handicaps to correspond via telephone lines. It commonly comprises a letter display, keyboard, and a cradle for the telephone handset and may additionally consist of a printer. A person types a message and transmits it, and another person with a telecommunication tool is the recipient of the message, viewing it on the display, and then typing and transmitting a reply.
TELECOMMUNICATION DEVICE (TDD): “Telecommunication devices are sometimes referred to as text telephone.”