Acoustic hailing devices are loudspeakers or megaphones that can be used to either convey voice instructions over a large area, or emit a loud, high frequency ‘deterrent tone’, which is designed to disperse targeted individuals or a crowd. They can be freestanding, vehicle-mounted, embedded in a riot control shield, or bodyworn (i.e. over the shoulder or strapped to the chest).
Whilst they can be used to target a small group of violent protestors and force them to disperse, they can also be used indiscriminately against peaceful protestors and bystanders. These weapons pose a risk of causing temporary or permanent hearing damage, depending on the model, distance and duration of exposure. When used continuously over prolonged periods where people do not have the option to disperse, such as in a prison setting, such misuse could amount to sensory (noise) torture or other cruel, inhuman or degrading treatment or punishment.
