I would try to get access to the PDF version of the Audio Book, and then have a couple of PhotoReads of it, and then play the audio book portion when you are in a place without distraction. As you listen, notice all the images that are triggered up into your conscious mind from and during the audio book, Create many Postviewing questions, with the positive expectation your inner mind will provide you/connect your conscious awareness to the portions of the book which answer those questions, in your case as the book is being read to you.
Good good. Keep going. And a tip for getting the most out of your mind maps. When done correctly, you will add a layer of branches to your mind map with key words and prhases from your last Activation pass. Go back and review your mind map periodically. Notice the flood of detail that bubbles up in your conscious mind as you recognize the key words and prhases. Doing this will help strengthen the reconstruction of those new memory threads in the future.