SONIC DOOMAn acoustic weapon disorients rioters and afflicts an invading army with nausea. It can create ‘ghosts’ and arouse animal passions. Fantastic? JACK SERGEANT, delving into the possible uses and abuses of infrasound, isn’t so sure. Additional material by David Sutton.The human ear can only hear a limited part of the sound spectrum. Above that range is ultrasound and below it is infrasound; although largely unheard, vibrations in these ranges can still affect the human body in ways that are quite different from the informational aspect of simply listening. These higher and lower registers of sound frequencies are, today,...