If I remember correctly SteveO mentioned listening to the audio version of Mind Over Back Pain over and over again when he recovered. I think he even had a version where Dr. Sarno himself read the book.
I totally think that listening to the audio version can be helpful. People learn in so many different ways, and hearing the audio may really help the message sink in. I am a big fan of audio books. I seem to be able to get through a book faster if I can listen to it while walking to class.
In the end, the effect of the book comes down to what you put in to it. Are you accepting the diagnosis? Are you becoming more active? Are you becoming more allowing of your emotions? These are the things that will ultimately determine the level of success you have with the approach.