These dampers use special anti-sound techniques to cancel out dangerously loud sounds, protecting the user's ears. Its tolerance can be manually set. It comes in the form of a pair of ear-phones that stick around the ear, and it can receive radio waves if programmed to do so. It is popular amongst people who work in high sound environments. The civilian types are programmed to respond to sound patterns in the Hyperwave sonic pistol, and to respond to them by increasing the volume as opposed to dampening it. They double the effective range of a Hyperwave sonic pistol against the person wearing them. Military/police types have no such limitation.