Detecting when someone is really listening to you

Hussein sent me a link to an interesting article by David Pescovitz at TheFeature.com: "Are You Listening to Me?"

Computer scientists at the Palo Alto Research Center, a subsidiary of Xerox Corporation, are developing software systems that analyze the subtleties of conversation. Unlike automated voice menus or other natural-language processing systems that attempt to identify what we're saying, the PARC software listens for how we're saying it.

I remember studying lots of work on the pragmatics of conversation in my linguistics classes as an undergrad. Things like Grice's Maxim, and speech registers. I used to believe that the written form of language is somehow more pure than speech, but of course that's silly. Everything you say, from the pitch of your voice to your prosody, carries meaning--often more important than whatever orthographic representation you use to transcribe it.