There are two versions of the audio books. The newer ones by Penguin Audio are worlds better than the older ones.

Also- I’m on book 17 and most of them have been absolutely delightful. But there have been about four that I just didn’t get into. It’s not necessary to read them in order and skipping the ones you don’t enjoy doesn’t take away from the rest of the books. If there is anything you need to know from another book there is a little author’s aside that fills you in. I agree, no need to read something you aren’t enjoying.