Wilhelm scream
The Wilhelm scream began to become popular when Benjamin Burtt Jr. found the original recording (which he found labeled as "Man being eaten by alligator") and put it into a scene in Star Wars Episode IV: A New Hope.  Burtt is credited with naming the scream after Private Wilhelm (after a soldier in The Charge at Feather River who was shot by an arrow and screamed).  Over the next decade, Burtt began using the effect in other films he worked on.  This included most projects with George Lucas or Steven Spielberg. It is used in all of the Indiana Jones movies. Other sound designers picked up on the effect, and use of the sound in movies became a tradition in the community of sound designers.