No.. You can hear songs and other "books" (the books without any pages just the cover picture) but any audiobook that has pages ( children's books) it will highlight the words as it is being read and automatically turn the pages but you just can't hear the story unless you plug in the headphones.
I have recently purchased several audiobooks ( before and after the upgrade) and I can only hear them with my headphones. What do I need to do so that I can hear them without my headphones?