Earlier this summer, at the re: MARS conference—an Amazon-hosted event focusing on machine learning, automation, robotics, and space—Rohit Prasad, head scientist and vice president of Alexa AI, aimed to wow the audience with a paranormal parlour trick: speaking with the dead. “While AI can’t eliminate that pain of loss, it can make their memories last,” he said, before showing a short video that starts with an adorable boy asking Alexa, “Can Grandma finish reading me The Wizard of Oz?”

Amazon scientists could summon Grandma’s voice with just a one-minute audio sample.