The wolf whistle has been a stock comedy sound for decades, long used in cartoons, sitcoms and radio comedy to signal exaggerated admiration when a character notices someone attractive. Its two-note shape made it easy to recognise even without a picture, which helped it survive as a shorthand joke. Online, the clip spread as a short reaction sound for videos, streams and memes, where creators drop it over entrances, reveals and flirty exchanges. It remains popular because the meaning is immediate, playful and understood across languages without needing any words.