How do my ears sense direction?

How do we hear a sound and immediately know where it’s coming from? That’s the question that CrowdScience listener Chiletso asked himself one day as he heard his son bounce a ball and instantly knew its direction. In this ear-opening episode, presenter Anand Jagatia sets out to discover what makes left, right, up and down, sound so different. First, Anand gets blindfolded, so that Alan Archer-Boyd, former auditory scientist and lead engineer at BBC R&D, can put his sound localisation skills to the test. It turns out that having two ears and pinnae, those flappy bits of cartilage on the side of your head, help a lot. Professor Eric Knudsen shares how the barn owl’s asymmetrical ears allow it to hunt mice, even in complete darkness. And Anand uncovers how far he can push his own spatial hearing. Blind activist and researcher Thomas Tajo teaches him how to echolocate like a bat, and Dr Lore Thaler explains what is going on in the brain of experienced echolocators. If you can, listen on headphones! Presented by Anand Jagatia Produced by Florian Bohr for the BBC World Service Image: Boy with hands at his ears Credit: Silke Woweries/Getty Images