Text Telephones, also known as TTY (Text Telephone) devices, are specialized communication tools designed for individuals who are deaf or hard of hearing. They allow users to send and receive typed messages over telephone lines, enabling real-time conversations without the need for voice communication. TTY devices typically feature a keyboard for typing and a display screen for reading incoming messages. To use a TTY, a person types their message, which is then transmitted as text to another TTY device. This technology can also connect to relay services, where an operator reads typed messages aloud to hearing individuals and types their spoken responses back to the TTY user. TTY devices have been essential in promoting accessibility and communication for the deaf and hard of hearing communities.