Who's calling--a bot or a human?

This week at Google's big conference, Google I/O, the tech giant unveiled a demonstration of the Google Assistant booking a haircut over the phone. To much of the audience's surprise, the bot sounded a lot like a real person--with human-like pauses and ticks. This feature, called Duplex, can only be used in exchanges that are functional and in "closed domains". This means Duplex could work perfectly with something like making reservations. The Network writer Jason Deign saw this robot-calling phenomenon coming last year in his piece "Could a robot fool you on the phone?"