A bit of trivia I stumbled on today. One of those things you notice without really noticing it until it’s pointed out to you. Like the ‘Welhelm Scream’:

This Hollywood tradition / inside joke of purposefully using the scream in a variety of films began with sound effects designer Ben Burtt (Star Wars, Indiana Jones) who noticed a particular scream being used in a number of Warner Brother’s films: Them in 1954, Helen of Troy in 1956, The Green Berets in 1968, etc. From then on, Burtt began slipping the Wilhelm Scream into every movie he worked on, beginning with George Lucas’s Star Wars: A New Hope. After that, it didn’t take long for the Wilhelm Scream to become Burtt’s personal sound signature, and other sound editors took notice. Following Burtt’s lead, editors like Richard Anderson (Poltergeist) and Mark Mangini (Gremlins) began using the Wilhelm Scream in their own work, feeding the fire and helping the little joke spread.

Many directors even started requiring that the scream be used in their pictures. More at that link. Here’s a compilation of just some of the 200+ movies and cartoons with it: