In this disturbing and wide-ranging account, acclaimed journalist Juliette Volcler looks at the extensive use of sonic weapons today against a long history of efforts by military and police forces to deploy sound against enemies, criminals, and law-abiding citizens. During the 2004 battle of the Iraqi city of Falluja, U.S. Marines bolted large speakers to the roofs of their Humvees, blasting AC/DC, Eminem, and Metallica songs through the city's narrow streets as part of a targeted psychological operation against militants that has now become standard practice in American military operations in Afghanistan. In the postcard-perfect historic center of Brussels, nausea-inducing sound waves are unleashed to prevent teenagers from lingering after hours. High-decibel, "non-lethal" sonic weapons have become the tools of choice for crowd control at major political demonstrations, from Gaza to Wall Street, and as a form of torture at Guantanamo and elsewhere. The same ear-splitting devices used by the U.S. military in Iraq, which produce jolts of up to 150 decibels, are at the ready for the London 2012 Olympics. In an insidious merger of music, technology, and political repression, sound has emerged in the last decade as an unlikely mechanism for intimidating individuals as well as controlling large groups. This enlistment of sound in war and law enforcement rests on more than a half-century of military and scientific research, but it has recently become an alarming trend. Extremely Louddocuments and interrogates this little-known modern phenomenon, exposing its far-reaching implications.