For information about how to make videos accessible, see http://www.ncam.org/.
..from NCAM - in a paper presented at CSUN in 1999 by Geoff Freed - session0058.html called "Recent Developments in Accessible Web-based Multimedia"
Benefits of Accessible Movie Clips
Deaf and hard-of-hearing Web users are the immediate and obvious beneficiaries of captioned movie clips. However, the benefits extend beyond this audience. Those using computers which lack sound capability, for example, can view captioned clips and follow the soundtrack visually rather than aurally. Also, as many educators have already discovered, captions used in conjunction with both audio and video can be a valuable tool for improving reading skills of children and adults.
A captioned movie's text track can also be used as a reference tool: some movie players have a "search" feature which allows the user to scan the text track for a specific keyword or phrase, making it easy to locate a specific spot in the movie clip. Depending on the software, this search function works even when a text track is hidden.
Another useful feature of a captioned movie clip is the transcript which is generated as part of the captioning process. Displaying a link to the movie's transcript allows the user to read the text before deciding if it is worth the time to download and view the movie. At a minimum, transcripts may be used by those who do not have any video-playback capability, as a partial substitute for the clip itself. For maximum accessibility, transcripts should always be used in conjunction with audio-only clips.
Like captions, the benefits of audio descriptions reach beyond the primary audience of blind or visually impaired users. Preliminary research has shown that described movies or television programs can help reinforce concepts or vocabulary in classroom situations. The same can be true for Web-based multimedia. Even more importantly, a Web-based movie clip is not limited to being played only in real-time. That is, the clip may be stopped, started and randomly accessed at will, or different audio and/or video tracks may be paused while other tracks continue to play. For example, during a clip that deals with a complex math equation, the video may be paused while the audio-description track delivers an in-depth explanation of the equation displayed on the screen. When applied to science or math multimedia, this technique allows for greater understanding of concepts that might otherwise go by the viewer too quickly.
Adding captions or descriptions to Web-based multimedia has one further potential benefit-- preservation of bandwidth. As more and more people log on to the Web, and as content providers utilize byte-intensive multimedia, access for all users will become slower and slower. As accessibility technologies are perfected, however, users will be able to request and download specific media components. That is, a blind user will be able to ignore the video portion of a movie clip but retrieve the program audio and descriptions only, thus avoiding the transfer of large amounts of unneeded data. Likewise, a deaf user may only want to download the video and caption portions of a clip, ignoring all audio.
In a paper about streaming video and audio, Norman Coombs and Richard Banks presented at CSUN 99 called "Enhancing Web Instruction: Using Streaming Audio And Video" session0150.html, the authors said:.
"Both audio and video can be used in ways to leave out students who are blind, deaf or other sensory processing problems, but they can just as readily be used to fully include students with disabilities into mainstream them into education. Obviously, audio delivery of information can leave the deaf and hard of hearing out in the cold.
Similarly, highly graphical and animated displays can leave blind and low vision students in the dark. Both communities fear the explosion of multimedia. Text materials over the internet have increased the social involvement of the deaf. similarly, with the use of speech synthesis, blind students have gained access to text-based materials as never before. They all viewed the adaptive computer and the information age as a boon to their inclusion into the world.
Now, they frequently find themselves on the outside again. However, when information is digitized, it has the potential of many different display modes. If multimedia makes use of redundant display modes, then it becomes accessible to all. This includes blind, deaf and other sensory processing disabilities. It also is congenial to people with different preferred learning styles. Even more, all people benefit when they are given information in redundant formats.
For example, hearing students watching a captioned video, do better on exams than when they watch the same video without captioning. "
Last updated: 8 March 2002