MEDUSA (Mob Excess Deterrent Using Silent Audio) is a directed-energy non-lethal weapon designed by WaveBand Corporation in 2003-2004 for temporary personnel incapacitation.
The developers claimed that through the combination of pulse parameters and pulse power, it is possible to raise the auditory sensation to a “discomfort” level, deterring personnel from entering a protected perimeter or, if necessary, temporarily incapacitating particular individuals.
[2] According to the U.S. Navy in 2004, the system would be "portable, low power, have a controllable radius of coverage, be able to switch from crowd to individual coverage, cause a temporarily incapacitating effect, have a low probability of fatality or permanent injury, cause no damage to property, and have a low probability of affecting friendly personnel".
[3] In addition to perimeter protection and crowd control, a proposed application of MEDUSA was "for use in systems to assist communication with hearing impaired persons".
However, Sierra Nevada Corporation had discontinued the project as of 2008, "possibly because it may have [been] shown to permanently damage human brain tissue".