Whelen is a well-known maker of warning sirens and lights for emergency vehicles, and its distinctive wailing tone has become shorthand for police and rescue services in film, television and online video. Clips labelled with the Whelen name circulate on soundboards as a ready-made emergency cue, even when the exact siren model is not identified. Creators keep using it because the sound is instantly recognisable, needs no explanation and immediately sets a scene of urgency, authority or approaching trouble.