British infantry officers in the First World War carried trench whistles, often made by Acme, to give orders over the noise of artillery and gunfire. A long blast was the widely understood signal to climb from the trenches and advance. That association survived through war films, documentaries and games, where the whistle still marks the start of an attack. Online the sound was clipped and shared on soundboards and in edits, turning a historic battlefield signal into a shorthand for bravely marching into any hopeless or chaotic situation.