Wow, that's a lot of listening.
I have trouble with audio books myself. I find the static voice detracts a bit from my imagination developing mental images of the characters.
I tried a couple where there were multiple actors doing voice overs, so to speak, but let's just say they should have stuck to being waiters.
They are a great alternative medium though. Definitely a wonderful thing for the vision impaired, elderly or people with dexterity issues, long road trips or people who just enjoy the style.
With great power comes Awesome irresponsibility.