I listen to lots of audiobooks and podcasts and can't say I notice a difference between the severity of my stutter on day when I do or don't listen to books. I will say that what does help me in regards to stuttering and audiobooks is to take notes and use techniques of professional voice actors who have to read out loud for a living. As someone who's trigger is usually anxiety and talking to fast because of it, slow down and be purposeful with what you say. It's hard tell because we're so used to hearing it but news anchors and audiobook reader typically talk about half as fast as normal and drop their voice a half octave lower than their natural speaking voice. A guy who hosted a trivia night at a bar told me that trick and it really helps. Stoping, resetting, and restructuring how you speak in that lower and slower way always helps me when I get stuck.