A Disruption Bubble Generator was a small device used to disrupt communications monitors. They would produce a spherical 2 meter bubble zone which interfered with any sound passing through it in either direction. Very loud noises, such as explosions, could penetrate the bubble, and the device itself was the size of a small box. Ostensibly sold as a way for music lovers to enjoy themselves in peace, the device rapidly became popular with those wishing to avoid any eavesdroppers. Audio Performance Incorporated was a major manufacturer of Disruption Bubble Generators, in particular the "Sheer Silence" model.