The exact origin of this recording is not clear, but its appeal is in how universally the phrase is understood. Online, creators use the clip as a shorthand reaction for relief and satisfaction, pairing the hiss with drinks, sprays, lotions, cleaners and novelty products. The tssst that's the stuff sound effect has spread through soundboards and short videos because it needs no setup, reads instantly even without visuals, and turns an ordinary application or first sip into a comic moment of pure contentment.