Speak it! Text to Speech
(1) App = https://itunes.apple.com/us/app/speak-it!-text-to-speech/id308629295?mt=8
One may be able to listen to a chapter of their novel or medical book through this.
I purchased the app for a reasonable $1.99. The free voices are quite good, and I never saw any reason to purchase to the additional voices.
BrettMD's rating = 5 stars