I think we all agree that consuming a book with one's eyes is "reading". However I am also pretty comfortable saying that when a blind person consumes a book with her fingers she is also "reading". But how about audio?
I used to follow a blog of a blind woman, and she would regularly talk about the books she was listening to, and she called it "reading". It sounded weird to me though. "You're not reading," I almost wanted to say, "You're listening."
Then I thought: what's the difference really? The contents of a book are being taken into your brain for interpretation. Does it matter which of your senses is retrieving the data, when it's the brain which finally turns it into a story?
So now I will sometimes refer to having "read" a book on CD. Or I'll mention a book I'm reading... but it still feels funny, as though I'm cheating a little. M will occasionally question whether I really "read" what piece of information. I think watching a movie based on a book definitely does not constitute reading. However if every written word is read aloud, why shouldn't listening to those words be considered "reading"?