From YouTube March 4, 2010:
recent studies have predicted that over 700 million people worldwide will suffer from hearing impairment by 2015. To address a clear need, the broadcast industry began running captions on regular video programming in the early 1970s. Today, closed captions on video are more prevalent than ever. But generating captions today can be a time-consuming and complicated process.
Making video easily accessible is something we're working hard to address at YouTube. One of the first steps we took was the development of a caption feature in 2008. In November of last year we released auto-captioning for a small, select group of partners. Auto-captioning combines some of the speech-to-text algorithms found in Google's Voice Search to automatically generate video captions when requested by a viewer. The video owner can also download the auto-generated captions, improve them, and upload the new version. Viewers can even choose an option to translate those captions into any one of 50 different languages -- all in just a couple of clicks.
Today, we are opening up auto-captions to all YouTube users. There will even be a "request processing" button for un-captioned videos that any video owner can click on if they want to speed up the availability of auto-captions. It will take some time to process all the available video, so here are some things to keep in mind:
Continued here: http://youtube-global.blogspot.com/2010/03/future-will-be-captioned-improving.html