On the 30-question game board, veteran "Jeopardy!" champs Ken Jennings and Brad Rutter managed only five correct responses between them during the Double Jeopardy round that aired Tuesday.
Usually, I am quite skeptical about this sort of thing, but I have to say I am pretty impressed. Note that the human players weren't just any players. Ken Jennings, and Brad Rutt are often cited as the best human Jeopardy players ever.
Watson did not have to process the audio, it was given the questions as text input. Since the players can read the questions too, this seems fair to me.
One point though is that it seemed to me watching that often the humans had the answer in mind but were not as fast as Watson at pushing their answer buttons. It used to be, in the old days of Jeopardy, that a player could ring in whenever he wanted, even before the question was completely read. Nowdays however, players must wait until the question is read completely before they press the button. It seems to me that Watson, knowing the question, would be able to ring in much faster than any human. This has nothing to do with "brain power," it's just human reflexes versus electronics.
Overall though, it's quite an achievement for Big Blue. Up there with their beating of Gary Kasparov at chess 10+ years ago.