Laugh tracks became standard on American television in the 1950s, when sound engineer Charley Douglass created the Laff Box to sweeten sitcoms recorded without a live audience. Shows from I Love Lucy to Friends kept the technique familiar for generations. Online, short versions were clipped for Instagram, TikTok and soundboards, where creators reuse the same burst of laughter as a ready made reaction. Its familiarity is the point, instantly signalling a sitcom moment even in a phone video.