"'How I Built This With Guy Raz' asks entrepreneurs to tell the story of how they made their name and..." — David Hepworth

Both traditional broadcasters and podcasters are betting heavily on the growth of voice-driven technology and so-called smart speakers, the theory being that it is as easy to ask Amazon's Alexa to play you the 'Guardian Books' podcast as it is to get it to play Capital FM.

The neurologist calls it 'Non-REM parasomnia'. For the sufferer, it might mean rising in the middle of the night, getting your motorbike out, going for a ride, and waking in the morning with no memory of the experience.

Bobby Bones is a young country DJ who does a widely syndicated morning show. He's at his best with his BobbyCast, in which he talks to Nashville up-and-comers such as Kelsea Ballerini and Lauren Alaina. Guests are encouraged to relax on Bones's couch and talk about anything they like.

The podcast 'A History of Jazz' began telling its story in February - 100 years after the recording of 'Livery Stable Blues' by the Original Dixieland Jazz Band, the start of jazz as a legitimate branch of music.