I have a Kindle DX and mostly use it for listening to (text to speech capability) books I bought on the Amazon Kindle store site while I drive.
I'm interested in knowing if it is possible to somehow change non-DRM books from other sites (Humble eBook bundle for instance) so that the Kindle would play audio in these books as well.
How can I modify the files, or trick the Kindle into activating text-to-speech for these non-Amazon books?
See image 1 -> Kindle store bought e-book with voice enabled menu:
See image 2 -> Non-Kindle DRM free other store bought (in this case a Wikipedia generated ebook)
As you can see voice is enabled for the Amazon bought book, but not the other ebook. I need a way to enable this for ebooks (for instance ebooks bought from the Humble ebook bundle) that are DRM free, but I still want to listen to whilst driving.