Dune is a film filled with gorgeous vistas from alien planets; skyscraper-sized spaceships; and some of the most beautiful actors working today. It's a joy to watch, especially on the big screen. But there's also an undersung element that ties everything together: sound design. It practically breathes life to the film — so much so that it makes Dune's wing-flapping ornithopter ships seem surprisingly real. The key to that magic, according to sound designers Theo Green and Mark Mangini, was a focus on capturing and using organic sounds, rather than fantastical digital creations.
Working together with Dune's director, Denis Villeneuve, the pair aimed to make "a real-sounding science-fiction film with things we've clearly never seen and heard before," Mangini said in an interview with Engadget."[It was] almost as if you put out a microphone and captured sounds as if those things actually existed. Everything we did ... is an outgrowth of that overarching philosophy to design a soundtrack for two hours and forty minutes that felt organic, as if we were [making] a documentary film."
That philosophy was essential to crafting the Bene Gesserit voice, a seemingly supernatural ability that allows members of Dune's religious order to control others. Think of it like the Jedi mind trick (Star Wars owes an absolute ton to Dune, don't forget). But instead of a hypnotic wave of the hand, the sound of Dune's voice is like a simultaneous kick to the gut and punch to the face. If you were somehow dozing off while the film's hero, Paul Atreides (Timothee Chalamet), tests his budding Bene Gesserit powers, you'd be easily jolted awake.
To make that otherworldly voice a reality, Green credits three elements. There's the voice actor Jean Gilpin, who he says is “brilliant” at crafting witchy and ancestral voices. The sound designers also recorded Dune's actors saying their lines several different ways, which they played back through a subwoofer and recorded the final output. That's an age-old technique known as "worldizing," or the act of recording audio that's being played back through speakers in a physical space.
The final component of the voice is the simplest: whenever a character starts to use that technique, the other sounds in the world fade away. In that early scene with Paul Atreides, we go from hearing the sounds of birds in the morning and a far-off thunderstorm to silence. That's an innately eerie effect that draws us into the interior world of the Bene Gesserit's powers: As Frank Herbert described it, they're calling on their ancestors and using advanced psychological techniques to manipulate others.
Green and Mangini went similarly old-school when designing the sound of Dune's ornithopter ships. They're the equivalent of helicopters in the film's universe, but they sound more like gigantic insects. To achieve that, Mangini says they combined the sounds of a large purring cat, a tent-strap flapping in high-velocity wind, and the fluttering wings of a large beetle. They weren't working from pre-existing sound libraries, either. Green had to bring a beetle into a quiet room and somehow get a decent recording.
All of that was just for the sounds of the ornithopters’ wings. To craft their propulsion system, the duo took recordings of beehives and modulated them to sound like RPMs revving up in a car's engine. The shifting of the ship's wings also came from an unlikely source: Mangini's Chevy Volt.
Once their work on Dune was over, the sound designers counted 3,200 new sounds that they developed for the film. Only three or four of them started out as electronic or synthetic sounds, Mangini says. That hearkens back to the way Villeneuve has approached visual effects in Dune and his earlier genre films: Go real whenever possible. For the sound designers, that push for authenticity also led to some inventive techniques. The gaping maw of Dune's enormous sandworms, for example, started out as the sound of Mangini half-swallowing a microphone.
Green likens the use of organic sounds as a way to avoid the "uncanny valley" that plagues some visual effects. Our eyes know when certain things look fake, and that takes us out of the reality of the film. "I think [the uncanny valley] is in sound," he said. "It's those tiny complexities and tiny nuances that you only get from an organically sourced thing that sells something as being real."