There is a text - to - speech engine for EPUB books. (goodereader.com)
The result is a fast, flexible speech engine that sounds more human — and less like a robot. (techcrunch.com)
Moon works with text to speech engines in the $ 4.99 version on sale at 50 percent off through January 4 (as I recall, it doesn't do TTS in the free version). (librarycity.org)