You've probably heard it a dozen times and never recognized it. The "Wilhelm Scream" began as an ordinary movie sound effect in a seldom-seen B movie. But it quickly became an inside joke among sound technicians, and has been in Hollywood blockbusters from Star Wars to The Hobbit.
The Wilhelm Screen compilation
In 1951, an actor/singer/songwriter named Sheb Wooley had a bit part in a Gary Cooper film titled Distant Drums. The part was so small that Wooley isn't even listed in the credits. But in the film, Wooley played the part of a US soldier who, while crossing the Everglades, is attacked and pulled underwater by an alligator, giving out a perfect movie scream. Oddly, he did not make the scream while filming the shot; in standard Hollywood practice, the scream was added later in post-production, after Wooley, who was known among Hollywood directors for his great "dying screams", was called back into the sound studio to record a number of screams and yells. Wooley's acting career was never that great (he did have a small role in the TV series Rawhide), but he earned fame in the music industry in 1958, when his song "Flying Purple People Eater" topped the charts.
After Distant Drums was finished, Wooley's onscreen dying scream was added to the Warner Brothers library of stock sounds, where it became free to use for any of the studio's movies. The next time the scream appeared was in the 1953 Western The Charge at Feather River. The scene called for actor Guy Madison to be shot in the thigh with an arrow, scream, and fall off his horse. Unfortunately, Madison did not have a very good movie scream, so the sound men dubbed Wooley's stock scream from Distant Drums into the soundtrack. Because Madison's character was named "Private Wilhelm", it would become known as "The Wilhelm Scream".
Over the next 20 years, the Wilhelm scream was a stock sound effect in many of Warner Brothers movies, including Them!, Helen of Troy, A Star is Born, PT-109, The Wild Bunch, and The Green Berets.
In 1976, sound designer Ben Burtt happened to notice that the Wilhelm Scream kept appearing in so many movies, and after some searching he found the original sound reel, labeled as "man eaten by an alligator". As an inside joke and as a personal signature, he slipped the scream into the new scifi movie he was working on for George Lucas, Star Wars. A little later, Burtt also inserted the Scream into the sequels The Empire Strikes Back, and Return of the Jedi, and then the Steven Spielberg movie Raiders of the Lost Ark, and its sequel Indiana Jones and the Temple of Doom. (In Temple of Doom, the Scream is actually used for a scene of a man being eaten by an "alligator".) Those movies, of course, became the most-seen motion pictures in the universe, and other sound effects people caught on to the joke and began adding Wilhelm to their own movies. By the 1990's, directors were in on the joke too, and some began deliberately asking for the Wilhelm Scream to be inserted into their soundtracks, as an homage to Hollywood history. Quentin Tarantino used the Wilhelm Scream in Reservoir Dogs, Kill Bill, and Inglorious Basterds; Peter Jackson used it throughout the Lord of the Rings Trilogy and The Hobbit.
Some of the films in which the Wilhelm Scream has appeared are: Swamp Thing, Poltergeist, Spaceballs, Willow, Gremlins 2, Beauty and the Beast, Aladdin, Batman Returns, Toy Story, Die Hard With a Vengeance, The Fifth Element, Titanic, Lethal Weapon 4, Small Soldiers, Planet of the Apes, Spiderman, Superman Returns, Cloverfield, and all of the Star Wars prequels. It's also been used in well over 150 TV shows and video game soundtracks. There is even a free iPhone App that makes the Wilhelm Scream whenever you toss your phone in the air.
In 2013, Ben Burtt, now working for Pixar, announced that he would no longer use the Wilhelm Scream in his own work. But the next generation of sound effects people will likely continue the tradition.