Communicating with computers by natural speech is a dream which goes back to Star Trek and 2001 (and well beyond, but this is not a history of science fiction). Recently, there have been clear advances in how computers understand humans – Alexa, Siri and their friends, as well as the new levels of call centre hell. But computers speaking to humans still sound robotic, because they are chaining words together and the intonation never sounds quite right. But now that’s changing too, with speech being constructed on the computationally intensive fly. And that may be important not just in its own right but as a step towards more fundamental changes in how people and machines interact with each other.