The songs of the ocean

As humans we're highly attuned to the cacophony of sounds we make and hear in the world around us, but little do we realise that there's a whole symphony of sounds to be heard in the ocean, too. Scientists say listening to the sounds of the ocean can help unravel the mysteries of the deep and paint a complex picture of what life is like beneath the waves. Steve Simpson is professor of marine biology and global change at the University of Bristol in the UK.