Sound off is a traditional military drill command used to make soldiers answer loudly and in unison, and it became widely recognisable through Full Metal Jacket, Stanley Kubrick's 1987 film about United States Marine Corps recruit training. The film's boot camp scenes, led by the famously abrasive drill instructor, turned its shouted orders into cultural shorthand for discipline, pressure and dark comedy. Online, the clip circulates as a reaction sound for laziness, disobedience and over-the-top authority, keeping the line alive far beyond its original scene.