LRAD sound weapons at protests use focused acoustic beams up to 162 decibels that cause permanent hearing damage, but distance and industrial earplugs provide effective protection.
Crowd-control weapons can cause severe and sometimes permanent injuries. Chemical irritants affect the eyes, skin and lungs first, causing scratches to the surface of the eye, painful skin reactions, ...
During protests in the USA, security authorities use LRAD systems for announcements and crowd control. How do these "sound cannons" work?