TREVOR COX is a professor of acoustic engineering at the University of Salford, U.K., and a former president of the Institute of Acoustics. He has presented twenty-four science documentaries on BBC Radio and written feature articles for New Scientist, Sound on Sound, and The Guardian. He is the author of The Sound Book, winner of an Acoustical Society of America writing award. He was awarded the Institute of Acoustics’ Tyndall Medal and the Institute of Acoustics’ Award for Promoting Acoustics to the Public. He currently holds the Guinness World Record for producing the longest echo in one of the Inchindown Oil Tanks.