Earlier quoted context omitted.
With this technology, one could produce high quality audio books without having access to high quality narrators by annotating the books with the voice, speed and such things. I wonder if a standardized markup exists to do so.
Don't end to end trained models already do this to some extent? Like raising the pitch towards a question mark, like a human would. TortoiseTTS has a few examples under prompt engineering on their demo site: https://nonint.com/static/tortoise_v2_examples.html
But the difference to good audio books is that you have * different voices for the narrator and each character * different emotions and/or speed in certain situations.
I guess you could use a LLM to "understand" and annotate an existing book if there's a markup and then use TTS to create an audio book from it and so automate most of the the process.