I am almost constitutionally incapable of listening to anything, be it podcast, audiobook, or even a long radio session, but I have plenty of friends who read books via audio almost exclusively, and there's no diminution in comprehension that I can see.
I'll admit that for some particularly fucky books, they've had to work a bit harder, but any variance between reading and listening w/r/t retention and analysis is hugely dwarfed by differences between individuals in those same areas.
~Camilla
Ghavrel is Ghavrel is Ghavrel
*MySmiley*