Not as far as I know. I doubt they'd ever have a true audio book version as the diagrams and images are quite important in some sections.
What I think they should do, especially now they have an app, is to have an option for the app to read it out. There was a very interesting article in one of the industry magazines a while ago regarding historical incidents where illiteracy played a part. Literacy rates have obviously dramatically increased since then, but there are still those who struggle to read (e.g. dyslexics) and would greatly benefit from such a feature.