Originally Posted by
Oneironaut
I may be able to answer that, only because I do it so much. Haha.
For me, sometimes it just takes a second for what was said to process. My mind might have been wandering, when the words were spoken, and I involuntarily felt the impulse to respond, before what was said really sank it. So, I end up saying "what?" as the sentence I'd just heard is piecing itself together in my head.
That's just me, though. :)
I've always wondered what people thought about that, though. No one's ever said anything about it, but I do it a lot. Lol.