This sound is the familiar wolf whistle, also called a catcall whistle or piropo whistle in Spanish-speaking contexts. It has long been used in comedy, radio, cartoons, and short-form internet edits as a quick signal of attraction or exaggerated admiration. Online, it remains popular because the meaning is understood immediately even in a very short clip. Today it is mostly used ironically in memes, reaction posts, and light prank content rather than as a realistic background sound.