I haven't really noticed that, but I tend to finish people's sentences for them. With my mother it's a necessity, and most of the time it's because she can't think what word she's looking for - her brain wanders before she reaches the end of a sentence.

DH talks and talks and talks when he gets excitable and I sat in a meeting with him the other day and had to gently kick him to let the accountant get a word in!

I don't think we can avoid thinking about the words we're hearing. We automatically process it and plan what to say next otherwise most conversations would be pretty dull and slow I think. There are certain circumstances where we need to listen more carefully than others, make the speaker aware that we're listening to every word they say before we answer, but for everyday conversation I don't think we need to beat ourselves up when we're listening and planning our own next sentence at the same time. That's what keeps a conversation going most of the time.

I agree about the voices adults use to kids. Fortunately it never really came naturally to me to do that so I haven't. I discuss things with my kids in much the same voice I'd use to anyone else. Listening to us when I'm driving and the kids are throwing out all kinds of weird questions and discussion topics would be quite amusing! And there are times when NOT listening to kids is a sanity saver. If I actually heard every word whenever DS opens his mouth to say something about Harry Potter I'd have been dragged away in a white coat by now!

Kerri.