Telecommunications Device for the Deaf (TDD)

A Telecommunications Device for the Deaf (TDD) is a specialized device that allows individuals who are deaf or hard of hearing to communicate over phone lines. It enables text to be typed and sent as signals, which are then translated back into text on the recipient’s device. TDDs often resemble small keyboards and displays, functioning similarly to a typed message exchange, making conversations possible without voice communication. They are crucial tools for facilitating accessible communication, especially before the widespread use of modern video relay services and captioned calls.