What you're describing is called "speech verification". Language education is an application I'm personally very interested in, and one that almost no one discusses in the speech community (I assume because of machine translation), so if you find any research papers please let me know! I wrote a little about it: http://breandan.net/2014/02/09/the-end-of-illiteracy/
The task is actually much simpler than STT. You display some text on the screen, wait for an audio sample, then check the model's confidence that the sample matches the text. If the confidence is lower than some threshold, then you play the correct pronunciation through the speaker. The trick is doing this rapidly, so a fast local recognizer is key. I've got a little prototype on Android, and it's pretty neat for learning new words. I'd like to get it working for reading recitation, but that's a lot of work.