Speech and language tools enable individuals with limited or no speech to communicate. For people who also have poor visual skills, there is technology with speech output that converts writing to speech. Phone companies provide assistive technology devices and services that enables those with speech limitations to communicate by using a computer, cell phone, or regular telephone. Below are links to companies that provides these services.
Sprint Video Relay
About TTY
TTY allows individuals with hearing loss to use the telephone for communication. This site explains how to use a TTY.
Dr. Hawkin's devices
The current configuration that renown physicist Dr. Stephen Hawkin uses is documented here: