For users who have hearing impairments the audio output must be conveyed visually on the screen. Most desktops provide
visual audio alerts and warnings. In console mode the system can also be configured to provide visual bells. There is a
"Visual Bells mini-HOWTO" written by Alessandro Rubini that provides the configuration details available at:
http://www.ibiblio.org/pub/Linux/docs/HOWTO/mini/.
TDD allows for the user you to communicate over the telephone using the
computer as a text terminal.
Zapata is a computer-based, high-density telephony project. The current version
is available for download as source code on at:
http://www.zapatatelephony.org/project.html.
Closed captioning provides text translation of spoken words to video display. Closed captioning can be used for distance
learning, video-teleconferencing, audio from a CD-ROM, and other types of interactive technology.