From Technology Review.

Google probably already knows what search terms you use, what Web pages you’re viewing, and what you write about in your e-mail — after all, that’s how it serves up the text ads targeted to the Web content on your screen.Pretty soon, Google may also know what TV programs you watch — and could use that information to send you more advertising, leavened with information pertinent to a show.

A system recently outlined by researchers at Google amounts to personalized TV without the fancy set-top equipment required by previous (and failed) attempts at interactive television. Their prototype software, detailed in a conference presentation in Europe last June, uses a computer’s built-in microphone to listen to the sounds in a room. It then filters each five-second snippet of sound to pick out audio from a TV, reduces the snippet to a digital “fingerprint,” searches an Internet server for a matching fingerprint from a pre-recorded show, and, if it finds a match, displays ads, chat rooms, or other information related to that snippet on the user’s computer…