As a black audio engineer, I thought I would take a second to talk about Long Range Acoustic Devices (LRADs), which are effectively sound cannons. They have been used to disperse crowds in the past, so I want to talk about them now as they can permanently damage your hearing. LRADs were originally invented as a weapon of war after the USS Cole was attacked in 2000. They are now occassionally used as devices to disperse large crowds (i.e. protests). They can be used for either making announcements (like a large bullhorn) or emit a loud tone.