Wherever we go, we’re surrounded by sounds. Although we usually we take them for granted, they can sometimes be used in ways we didn’t expect. At the more obvious end of the spectrum, the soothing sound of a river can send off serene chemical reactions in your brain; likewise, the sound a construction workers drilling in concrete at 6am can do the opposite. The sound of someone’s vocal chords can equally inspire you to rescue someone from the flames of a burning house, or to join in a riot. Sound can heal or hurt. It has an undeniable and surprising power, given that it is only really vibrating energy. This list offers some fascinating ways people have harnessed this natural force.