This is a huge problem! I did some work for the Assistive Technology Industry Association (ATIA) and video is very inaccessible. This is a problem not only for people with bad or impaired hearing. Imagine trying to figure out what a video was trying to demonstrate if you were blind!
W3C has created the Web Acceptability Initiative (WAI) with the goal of creating a common set of web standards so that all people can access content. Check out the WAI homepage for best practices and code examples: http://www.w3.org/WAI/
I have a feeling I might use the "accessible" version of a page more regularly, if it were widespread enough for people like me who don't need it to be aware of it.
W3C has created the Web Acceptability Initiative (WAI) with the goal of creating a common set of web standards so that all people can access content. Check out the WAI homepage for best practices and code examples: http://www.w3.org/WAI/