Educators are becoming increasingly aware of the power of video to engage students in this multimedia world. Video content, however, can create barriers for some individuals with disabilities, including people with hearing impairments. The solution is to caption the video, so that content that is available via audio is simultaneously accessible via text to those who can't hear the audio. For more information on multimedia accessibility, see the AccessIT Knowledge Base article How do I make multimedia accessible?  Open captions are always visible on the screen, whereas closed captions can be turned on or off by the user. For a comparison of these two approaches to captioning multimedia, see the AccessIT Knowledge Base article What is the difference between open and closed captioning? 
The National Association of the Deaf (NAD), through its Captioned Media Program (CMP) , has amassed a collection of over 4,000 open-captioned educational video titles. CMP's mission is to provide everyone who is deaf or hard of hearing awareness of and equal access to communication and learning through the use of captioned educational media and supportive collateral materials. CMP provides free-loan educational and general interest open-captioned videos to individuals with hearing impairments, as well as to teachers, parents, and others who work with such individuals.
CMP recently began providing many of its open-captioned videos online via streaming media. Streaming media allows subscribers to instantly access these titles from the CMP website, eliminating shipping time for video cassettes. The current project calls for streaming of approximately 450 titles, covering content for a variety of audiences and educational levels. Titles are organized on the CMP website into twenty broad categories and many more subcategories. Broad categories include arts, biographies, business, careers, computers and technology, geography, history, language arts, literature, mathematics, science, social science, and many others. Subscribers must register for this service, but there is no registration fee.
-  How do I make multimedia accessible?
-  What is the difference between open and closed captioning?
-  Captioned Media Program (CMP)