Karaoke, video captioning, text-to-speech - what have i missed?

I have a client here in Hawaii who has been championing a local student reading program with a graphed success rate, he has asked me to research web technology that would provide the same service in a browser.

The program does not test, or call on students to read, but instead, distributes donated books to a class and the instructor reads as students follow along. This method preserves student dignity and exposes them to the benefits of the written word: vocabulary, visualization, vocalization. The proposed web solution would show a few lines of text, highlight each word as it is made audible, and require the student to click a button to advance to the next portion of text.

We have discussed current technologies: karaoke tech (but the technology is not web browser deliverable), video delivery with emphasis on captioning (possible, but production is burdensome), and text-to-speech seems to be web deliverable and production friendly, but the technology would be a licensing hurdle (sample http://tts.imtranslator.net/OnUK ).

Do you have any ideas on current technology that could accomplish the task?

That sounds a lot like what’s being done with Apple’s iBooks, where you can turn on a setting so that words are highlighted as they are read out by the device (iPad etc.). It’s used mostly for little children’s readers, of course, but could be adapted. I presume it’s mostly powered by JS.