allows people who are deaf, hard of hearing, deafblind, or have a speechdisorder to place calls to standard telephone users via a keyboard or assistive
Accessibility. Retrieved 2020-08-31. "Speech and Communication Disorders". National Institutes of Health. "Hearing Disorders and Deafness". National Library
with speech impairments. When Title IV took effect in the early 1990s, it led to the installation of public teletypewriter (TTY) machines and other TDD (telecommunications
led by Robert Stanfield), the confidence motion passed. The first batch of TDD units (also referred to as TTYs), designed to allow the deaf to communicate