You've heard it time and time again in movies, TV shows, even video games: a throaty, histrionic wail that usually goes with someone falling from a great height or getting blown up. It's known as the Wilhelm Scream—and it's all Star Wars' fault.
The scream itself was first recorded in 1951—by singer and actor Sheb Wooley—for a film called Distant Drums, in which a soldier is bitten by an alligator. Twenty-some-odd years later, sound designer Ben Burtt found the recording (in a can marked "man eaten by alligator") and was so taken with it that he mixed it into a scene in Star Wars: Episode IV—A New Hope.

Burtt would then proceed to incorporate the Scream—named after a character that uttered it in 1953's The Charge at Feather River, Private Wilhelm—in most every film he worked on for George Lucas or Steven Spielberg, including all the Indiana Jones flicks.

It became "a thing" in the sound designer community, and the Scream became ubiquitous, appearing in countless movies over the past 20 years or so. Here's just a taste of its omnipresence.

Most recently, the Wilhelm Scream made itself heard in the Halo: Reach video game, in the beginning of the "Tip of the Spear" level. It'll rear its frightened little head again sometime soon. And when you hear it, raise a glass. After all, Wilhelm died for your pleasure, hundreds and hundreds of times.

http://www.youtube.com/watch?v=4YDpuA90KEY