That sounds really frustrating, it looks like you put in a ton of effort. Unfortunately I remember from my time as the Video Grader it can be difficult to evaluate the amount of effort some of the unique media can take to produce.

Why don't you create a grading metric for future audio books? I don't think I have seen anyone create an audio book before and I bet the graders would appreciate having another grading resource to fall back on that isn't just podcasts.