Scientists are teaching robots to laugh

Robots still have a long way to go to fully understand human laughter, which can signify anything from happiness and amusement to sexual interest, embarrassment or anger. Also baffling to machines is the fact that laughter can vary: there is the classic ha-ha-ha laughter, speech laughter (when you speak while laughing) and smile speech (talking while smiling). Distinguishing among these types will be vital for better human-robot interactions. “Because laughter is such a crucial part of what it means to be human, we won’t have convincing artificial intelligence until our machines can laugh along with us,” says Gary McKeown, a psychologist at Queen’s University Belfast who also works with Nao but was not involved with the new research.

Further, for robots to laugh convincingly with humans, they must be able to tell when a person wants such an interaction. “The inviting laugh is longer and louder and has a higher pitch than an isolated laugh,” says Khiet Truong, a computer scientist at the University of Twente in the Netherlands who studies how people interact with virtual agents and robots. “Humans respond to an inviting laugh within half a second on average,” Truong says. “We hypothesize that robots should do the same—otherwise it is no longer natural.”