Voice assistant apps like Alexa, Siri and Google Assistant are about to transform the economics of the web.

Nearly a quarter of all households in the US and in China already have a smart speaker in their homes, allowing them to play music, order a delivery or find out the news, all by simply talking to their computer. Meanwhile an estimated 2.5bn smartphones now carry these wannabe AI oracles.

Manuela Saragosa asks Silicon Valley analyst Carolina Milanesi whether this new technology could one day rival the conversational prowess of the ship's computer on Star Trek. And what kind of vision do the likes of Google, Apple and Amazon have for it?

Meanwhile journalist and author James Vlahos explains why he thinks their advent is bad news for anyone who wants to maintain any visibility on the internet. And we put his criticisms to one of the major players - Andrew Shuman from the team behind Microsoft's Cortana voice assistant.

Producer: Laurence Knight

(Picture: Amazon Echo Sub subwoofer; Credit: Philip Barker/Future Publishing via Getty Images)