Silencers, also called suppressors, are tube-shaped devices that, when screwed into the muzzle of a gun, slow the decompression of gases that propel a bullet forward, thus reducing the “pop” sound of gunfire. […] “I don’t think in real life, in practical applications, that there is that great of a tactical advantage to use a suppressor, especially for something like a mass shooting,” Gutowski said.
Source: wiktionary