Close captioning...

Question: How does close captioning work for live TV?

Had this question come up this weekend because we were watching the world hockey tourney with close captioning (Canada won Silver). Is there speech recognition sofware behind this, is it some person madly typing, or is TV on some sort of delay so people can correct spelling mistakes? I bet that there was no way speech recognition software was good enough, so there had to be people madly typing on the other end.

Apparently I was right (for once). So here's the explanation of how real time captions are generated. Basically you have a bunch of stenocaptioners (people with special typewriters) writing at 250 words per minute as the backend to this system.