I've had the subtitles turned on for about a year now and it wouldn't take more than 2 hours of watching broadcast TV with subtitles to realize this isn't a good solution. I've noticed the following.

1. Audio track is censored, Subtitles are not or Vice/Versa. 2. Actors Improvise the audio, the Subtitles are based on the script. 3. English Translations were done by the cheapest person possible so lots of partial words because they weren't clear and the transcriber didn't understand the context. 4. A recent show (2011) seemed to have a symbol every other character, I'm not sure if this is a Double-Byte Character issue, or just a bad translation. 5. Several shows such as American Idol and America's Got Talent display song lyrics and I'm not sure but I would think singing would require changes to the Algorithm.

I wish you well with the idea, but now you have a little more information.

And they are translations not speech-2-text.

Movies are also subtitled in the same language for the hearing impaired.

How about music lyrics?

For training speech recognition? Songs strikes me as poor training data.

I wasn't arguing against movies, just that subtitles rather than a final script isn't the best data source.

well not exactly for speech recognition when it comes to entering text into a document but as spoken word to subtitle. I think there was a TED video that showed this somewhere..