https://laist.com/shows/the-frame/jurassic-world-the-sound-design-behind-the-indominus-rex

I was never a big dinosaur fanatic growing up——I didn’t have pictures of dinosaurs in my room or cool T-rex shirts—but I found it interesting how movies and books alike could recapture the essence of creatures that had existed so long before us, particularly the sounds that they made. While watching Jurassic World (2015) for the first time in a few years recently, I couldn’t help but be drawn to the sounds of the dinosaurs, particularly when Zach and Gray first encounter the Indominus rex while stuck in a remote part of the woods. As opposed to other animals like cows and dogs, there is no basis for understanding these creatures. Thus, in creating an intense and intimidating set of external diegetic sounds, filmmakers have to be very particular in how they portray the screams of the dinosaurs, particularly the tyrannosaurus rex. 

Through my research online, I found an article where the film’s sound engineer, Al Nelson, discusses the process of making this sound. With the film looking to unveil the scariest dinosaur of the series, the Indominus Rex, it needed a collection of sounds that had never been used in the dinosaur space. Thus, in looking to make a mutated dinosaur, Nelson used a variety of real animal sounds to construct the voice of the Indominus Rex. From pigs, to leopards, to wild monkeys and more, Nelson was able to blend the sounds of many wild animals, even resorting to looking up “annoying animal scream” on the internet to find the loudest and scariest composition. 

But the hardest part, as Nelson noted, was trying to capture what sounds would have really scared someone if they were face to face with a dinosaur like the Indominus Rex, and how he could “[give them] chills.” While the appearance of the dinosaur is important, its sound played a pivotal role in adding a sense of horror and intimidation throughout the movie.