Movie audiences assume that the sounds on the screen were recorded during filming, and that maybe a second person added big effects like explosions. In truth, that’s both the misperception and the goal.
Warner Bros.’ “Dunkirk” presented unique challenges for the sound team. Richard King was supervising sound editor and says, “Usually you get a little useful material in production recordings. But with this,it was pretty much a blank slate.” That’s because it was filmed on the northwest French coast under harsh conditions including rain and wind, not to mention noisy Imax cameras.
The results are amazing visually. But aurally, it meant starting from scratch. “Basically, all we were able to use was just the voices,” says King. “[Sound mixer] Mark Weingarten did a great job with the dialogue; we only needed a few lines of looping,” but other sounds were unusable.
The Christopher Nolan script relates the 1940 events from three POVs: land, sea and air. The filmmakers would not settle for generic plane or boat sounds.
“For the aerial sequences, we recorded Spitfires using 20-25 microphones scattered throughout the plane — in the engine area, in the fuselage, just behind the pilot — then we recorded a lot of rattles, shakes and vibrations. We wanted to convey physical sensation of being in the plane.”
For a sequence in which two soldiers run carrying a stretcher, King estimates they used 30-40 tracks. “But for scenes like the ship getting torpedoed, the number of tracks was into the hundreds.”
While King and his team gathered sounds, re-recording mixer Gary Rizzo and his group mixed these layers of sound with the dialogue and Hans Zimmer’s score.
Rizzo makes a comparison: In a restaurant with friends, a person’s ears hear everything, but the mind blocks out the extraneous noise. “Your brain is like a mixing console,” says Rizzo; “there is a lot of filtering.” With film sound, “It’s all about making the right choices.”
King and Rizzo — who have both worked on most of Nolan’s films and who are both Oscar winners — agree that the filmmaker’s approach is unique. “Chris uses sound in a way that many others try but few achieve,” says Rizzo. “He almost hijacks your cardiovascular system. It’s about pulse, pace and purpose.”
Adds King: “He likes a punk quality to his tracks, raw and aggressive and a bit in your face. We didn’t want anything familiar, so it wouldn’t remind the audience of other war movies. That would diminish things. We tried to rethink every sound.”
For example, when a bomb falls in most battle films, the sound gets fainter before impact. “But when you think about it,” says King, “the noise should increase in pitch as it gets closer. We reversed all incoming shell sounds so they rose in pitch.”
King, like others on “Dunkirk,” did a lot of research. In reading interviews with Dunkirk participants, he discovered a lot of their memories were sound-related. “These were kids, very green, experiencing a lot of things for the first time. Many things sounded different from what they expected — a bomb falling in the sand or bullets whizzing past. A lot of sounds were startling or surprising to them.”
King’s team made sure the sounds in “Dunkirk” are authentic. But when a person is in peril, “you have an altered sense of perception,” says Rizzo, and that’s what Nolan wanted to capture. Every sound the audience hears — even the subliminal ones — was carefully placed. However, the irony is that all of this work is intended to make the effort unnoticed.
As King states, “You want the audience to feel like it all happened on the day they shot the movie. You don’t show your cards.”
It’s a survival film, adds Rizzo; “We were not trying to make it pretty,” but to be authentic.
There’s another element involved in the complex sound of “Dunkirk”: magic.
“You can talk about the nuts and bolts,” says Rizzo, “and that’s like showing the process of how a magic trick is achieved. But in performing the magic trick, there is showmanship and intensity and that’s what the audience really wants. The magic is about the decisions and the performance. And that’s Chris.”