Why does the thought of giving a talk to an audience fill so many of us with sheer terror? Marnie Chesterton investigates for listener Nhial, who has seen his fellow students in Morocco become panic stricken at the prospect and wants to know the reason for our anxiety. According to one study, 77 per cent of us share that fear. Marnie finds out about the relationship between stress, our brains and our voices from research associate Dr Maria Dietrich at the University Hospital, Bonn University. She talks to Nhial’s tutor, Professor Taoufik Jaafari, at Hassan II University of Casablanca about the challenges facing his students. And she visits the National Theatre in London to get some expert training from Jeannette Nelson, head of voice, who works with some of the world’s leading actors. Could there be an evolutionary explanation for the purpose of public speaking? Is it something we actually need to be good at? Marnie asks evolutionary psychologist Professor Robin Dunbar at Oxford University and gets some surprising answers. She meets psychologist Dr Preethi Premkumar at London South Bank University, who has developed virtual reality therapy with colleagues at Nottingham Trent University, and tries out the treatment herself. Presenter: Marnie Chesterton Producer: Jo Glanville