The dentist drill sound comes from the real dental handpiece used in clinics, whose electric motor creates that distinctive high-pitched whir patients know from fillings and cleanings. Recordings of the tool spread as a stock sound effect in cartoons, horror films and comedy sketches, then moved online to soundboards and video edits. It endures because almost everyone shares the same memory of hearing it up close, so a few seconds is enough to signal pain, fear or an unwelcome appointment without any visual setup.