Word of Mouth

In 1861, Johann P. Reis announced that he'd invented the microphone. To celebrate 150 noisy years, Michael Rosen is joined by John Liffen, Curator of Communications at the Science Museum, the social historian, Clare Langhamer, and 'digital futurologist', Peter Cochrane. Steve Punt, meanwhile, reports from an alternative universe where the microphone was never invented. Producer: Peter Everett.