MEDUSA (Mob Excess Deterrent Using Silent Audio)

The device – dubbed MEDUSA (Mob Excess Deterrent Using Silent Audio) – exploits the microwave audio effect, in which short microwave pulses rapidly heat tissue, causing a shockwave inside the skull that can be detected by the ears. A series of pulses can be transmitted to produce recognisable sounds...

MEDUSA involves a microwave auditory effect "loud" enough to cause discomfort or even incapacitation. Sadovnik says that normal audio safety limits do not apply since the sound does not enter through the eardrums.

Microwave ray gun controls crowds with noise