Designing the Dynamic Sound of Oppenheimer – with sound designer/sound supervisor Richard King

Director Christopher Nolan and his long-time collaborator – 4x-Oscar-winning sound designer/supervising sound editor Richard King at Warner Bros. Post Production Creative Services in Burbank – aren’t afraid to dig deep into the field of physics. Their previous collab – the film Tenet – explored the idea of entropy and reversing the arrow of time. This time, they take on quantum mechanics, black holes, and atomic bombs in Oppenheimer.

Nolan’s tasks for King on Oppenheimer were no small feat. He sought the epic sound of an atomic explosion and the sound of infinitesimal quantum particles and waves. He also asked King to create sounds that span decades and distances, and to craft sonic expressions of celebration and horror. It was an expansive scale of sounds in every way, and King delivered.

Here, King talks about creating a range of explosions that lead up to the Trinity test, designing the sound of that atomic explosion based on actual eyewitness accounts, manipulating natural sounds to work with Nolan’s practical effects for the quantum world, finding analog devices to record for the tech of that time, and so much more!

Oppenheimer | Official Trailer

You were tasked with recreating one of the loudest man-made sounds – an atomic explosion. But to really understand how loud something is, you need a point of reference. In Oppenheimer, we get the idea of scale thanks to a range of different explosions – the Halifax ship explosion, and the implosion device tests. Can you talk about that process of creating a range of explosions that increase in scale up to the Trinity test?

Richard King (RK): Interestingly, Oppenheimer himself studied some of the largest phenomena in the universe (black holes) down to the smallest (quantum particles), and Chris [Nolan] wanted to exhibit that range of scale and give the audience a visceral sense of the enormous power that’s latent in quantum particles, which is ultimately revealed in the Trinity test.

For the Trinity test explosion, my inspiration was a sound that has occurred on rare occasions in nature. I found a recording of one of these events to use as reference. There are a number of elements, all chosen to help achieve this sound, which almost sounds like an enormous cosmic door slamming. The Trinity test explosion needed to be a sound unlike any other explosion. The witnesses to the test all mentioned the sound in interviews conducted shortly after the test. We accentuated the scale of the blast by making the bunker and everything in it shake and tremble when the shock wave finally hits.

The Trinity test explosion needed to be a sound unlike any other explosion.

Working back from that in the explosion world are the tests leading up to Trinity. They used fairly large amounts of conventional explosives which got bigger and bigger as they tried different methods of detonation. It’s fascinating how the implosion lenses work. They’re explosives that are shaped to focus their force inward. They detonate within a millisecond of each other, forcing the energy to compress the plutonium core, which is about the size of an orange. That orange-sized sphere is what makes that 20-kiloton explosion happen.

And then there was the Halifax explosion, which was the largest man-made explosion ever until Trinity. Oppenheimer is describing the event to the other physicists so there’s a more impressionist approach to that scene.

Oppenheimer is describing the event to the other physicists so there’s a more impressionist approach to that scene.

The smallest objects on the scale are the quantum particles and quantum waves that haunt Oppenheimer’s imagination when he visualizes their immense latent power. There was nothing exotic in this sound. We just kept fiddling around until something stuck. Chris created all those visuals practically; they’re not CGI. We worked with the same philosophy and created the sounds by manipulating natural sound elements.

The Trinity test explosion had this really sharp crack sound at the start. It was more of a crack than a boom. The attack of that sound envelope was so intense…

RK: I read every book I could find on Oppenheimer and the Manhattan Project. There were a lot of very interesting eyewitness accounts which were recorded shortly after the Trinity test, interviewing the physicists who were there and stationed at different distances from the tower. Some described it as sounding like a Howitzer going off right by your head, or a freight train roaring by, or like an odd kind of thunder that kept on going for a long time.

It was a very sharp BANG that had a very long decay, like thunder rumbling around the hills surrounding the tower.

The detonation happened in milliseconds; it was a very sudden event. It was a very sharp BANG that had a very long decay, like thunder rumbling around the hills surrounding the tower. The site was in a large, shallow valley surrounded by low hills so the rumbling went on for quite a while.

It was inspiring to read these firsthand accounts. They gave me a good sense of what the experience must have been like. They all mentioned the intense light and the colors, of course, but almost to a person they also described what it sounded like and each one of them described it a little bit differently. I took all those descriptions and used them as inspiration for the sound we came up with.

As you mentioned, dir. Nolan is really into practical effects and created an explosion (not atomic) to capture on film. Were you on-site to record the sound of that?

…we try to make the sound effects track sound like production sound…

RK: I think if Chris had his druthers, he would use only production sound recorded on set on the day. Not being able to do that, we try to make the sound effects track sound like production sound; the goal is to make you feel as if you are really there.

We avoided any electronic or synth sounds. So our sound design is derived from natural sounds that have been manipulated. But they all have a basis in actual sounds recorded in the world.

Much of what makes a good explosion recording is the location it was recorded in…

I sent a recordist out to capture one of those explosions, and they’re good recordings, but they were brief events. Explosions are hard to record. Much of what makes a good explosion recording is the location it was recorded in, like canyons or enclosed valleys that contain the sound. Otherwise, the sound dissipates very quickly and it is just a big, singular boom.

In the film, as you see the atomic bomb explode (but before the shockwave hits), you hear the sounds of breathing and just close human sounds in this epic moment of history. Can you talk about your approach to that moment?

RK: It’s interesting that a lot of the critics who have mentioned sound understand silence to be strictly a directorial conceit. Chris designed that scene to take maximum advantage of the 30 or 40 seconds it took the shock wave to hit the bunker. There’s a feeling of magical awe at the sight, which is accentuated by the prolonged silence.

That was the focus, to create a suspended moment.

That was the focus, to create a suspended moment. It must have been incredibly powerful, majestic, and awful. We hear Frank (Oppenheimer’s brother) say, “I guess it worked.” What do you say after something like that? We hear Oppenheimer breathing and recalling that phrase from the Bhagavad Gita that he read for Jean Tatlock, which now has a different meaning for him and has a different resonance for the audience.

I love the way the tension builds up leading to the Trinity test, using small detailed sounds like the keys turning in the machine that sets the timer for the ignition, and the countdown clock buzzes – smaller sounds to set up something that is going to be so huge. Can you talk about your approach to designing those lead-up moments to the Trinity test?

RK: We tried to be as accurate as we could while still making it interesting, using the analog testing devices that they would’ve used at the time. Chris, the production designer, and the Art Dept. did a lot of research to determine what devices they actually used as timers, fail-safe devices, etc.

…we rented period devices from prop houses like the old hand-crank detonators…

They were using what was then state-of-the-art equipment including lots of different kinds of cameras, both 35-millimeter Mitchell cameras running at sound speed and some Fastec cameras that ran at the unbelievable frame rate 10,000 FPS. That’s how they could get those still images of the explosion developing by the millisecond after the detonation.

So we dug around a bit to find out what all that gear might sound like. Then we rented period devices from prop houses like the old hand-crank detonators that they used on the implosion tests. We were trying to be as true to the time as possible.

Following the Trinity test explosion, the bombs they made to drop on Hiroshima and Nagasaki were loaded onto trucks. I loved how simple the sound is here, just wooden crates and heavy chains. It’s very low-key for something that’s life-changing, and world-changing. That juxtaposition is interesting, having bombs of epic proportion and scale (and what it’s going to do to the world) represented by commonplace sounds of wood crates and metal chains…

RK: There’s a tension in that period of the movie. It’s anticlimactic because the Trinity test was successful and the scientists were made to understand that it’s all out of their hands now; they’re excused and no longer needed. I imagine for them it must have been just a weird time of intense activity leading up to Trinity and then nothing. They’ve done their part and now it’s in the military’s hands. There was nothing left for them to do. It must have been a strange time for them.

We tried to make the chain clanking on the sides of the truck as they drove away hypnotic as Oppenheimer watches.

We tried to make the chain clanking on the sides of the truck as they drove away hypnotic as Oppenheimer watches. He’s just in a state of shock, really. In a small way, it’s like finishing a movie in that there’s all this frantic activity and you’re really busy and your mind is racing and then you finish the movie and you’re dismissed. You’re no longer needed. That’s probably a microscopic version of what Oppenheimer and the other physicists felt.

Oppenheimer gives a speech to the crowd in the auditorium at Los Alamos. They’re cheering and they’re stamping their feet. In the IMAX mix, this moment felt as powerful (sound energy-wise) as the atomic bomb going off. There was so much energy in that scene. And then it goes into a subjective POV where he doesn’t really hear the crowd anymore. He’s envisioning the blast and he’s hearing the rumble, and the cheers are mixed with screams and it takes on this edge of terror. Can you talk about your design for that sequence?

RK: That was a scene that we all worked on. Chris and picture editor Jennifer Lame created the template for us to use. It came together on the stage with all of the elements that everyone had brought to it. Chris wanted the scene to segue from a jubilant victory celebration to a nightmarish and nauseating one as Oppy visualizes the horror of it all. They’re getting drunk, people are ecstatic and laughing, and some of them are sobbing or throwing up. Different people were registering the event in different ways, but we see the scene through Oppenheimer’s eyes.

Chris wanted the scene to segue from a jubilant victory celebration to a nightmarish and nauseating one as Oppy visualizes the horror of it all.

Oppenheimer is an interesting character because he obviously knew all this was going to happen. The fact that the bombs were going to be dropped on human beings wasn’t a surprise to him. In fact, he helped pick the targets. But now facing the consequences with no problems left to solve regarding the project, it all came down on him in that one scene. He has a sudden sickening realization that this isn’t a celebration. This is a funeral. This is a funeral pyre and the world starts to come apart a little bit. He loses his ground and kind of loses his mind for a moment. He must have been (as they all must have been) in a state of shock and that scene is Oppenheimer’s version of that shock.

He has a sudden sickening realization that this isn’t a celebration. This is a funeral.

One of the great strengths of the film and one of the gifts Chris has given us is a bit of a view into what that experience might have been for them, seeing all that through Oppenheimer’s eyes. By that time, we’ve gained a little understanding of how the bombs work and even a little quantum physics – enough to know that it’s not magic or hocus pocus. We understand that it’s a force of nature that’s been unleashed and there’s no putting the genie back in the bottle. The audience, of course, knows what happens after those trucks leave, and the decades of trouble that followed.

It’s a moment that really resonated with me and resonates with a lot of people when they see the film. Oppenheimer’s work ultimately ends with something unbelievably tragic, but he does a great job of building up the excitement for the scientists building the bomb. These scientists are really stoked to do this. And initially, they have a very good reason to do it knowing that Hitler was working on a bomb. So it’s really kind of an exciting adventure and that makes the realization (rubbed right in his face) that much more disheartening and sickening and terrifying.

After the bombs are dropped on Japan, we hear Truman’s news broadcast. Was that actually the archival news broadcast or was that something that you created for the film?

RK: No, but it’s verbatim, it’s exactly what Truman said. And just like after the Trinity test, there are people who are jubilant and happy because the war’s probably going to be over very soon and because we stuck it to the Japanese, who, after all, started the war. And then others who are of Oppenheimer’s mindset, mostly physicists who actually designed and built the bombs. They are not sure if they should congratulate each other or cry on each other’s shoulders.

I really love that we got to see Los Alamos before it became a whole town. Oppenheimer goes up there with his brother and a few others and they’re just sitting around the campfire. It’s peaceful and beautiful. You hear the beautiful desert winds and the sparks from the fire. I love that we got to experience that before the place gets blown to hell…

RK: They built this bustling town, which was a self-contained city for those years. People couldn’t leave, or come and go, except by permission. It’s really quite a transformation. It was a place he loved and he always wanted to combine New Mexico somehow with his work. And he sure did that.

What was your favorite part of working on Oppenheimer? Now that it’s all over, what has stuck with you the most about this experience?

RK: There’s no particular part. Every single moment in the film was given a great deal of attention and we tried to give each shot a sonic reason to be there – give it some signature, or have some interesting sonic information conveyed. Even the simplest scenes, such as Oppy’s wife Kitty taking in the laundry, we worked very hard on.

Every single moment in the film was given a great deal of attention and we tried to give each shot a sonic reason to be there…

Re-recording mixer Gary Rizzo did a remarkable job with the dialogue cleanup. Almost all of it is production sound, there’s practically no ADR in the film. Both the IMAX and 65mm cameras are loud, so getting rid of that noise was a big job.

Re-recording mixer Kevin O’Connell mixed both sound effects and music and did a fantastic job with both. Ludwig Göransson’s music for the film is fantastic, scoring the excitement of the beginning of the project and the excitement of the ’20s and what that must have been like. The ’20s must have been a decade like the ’60s in that so much was happening in art, science, and culture. Ludwig did a great job of conveying that excitement. Then, into the next period of the war and intense war work on the bomb project and then the aftermath, he really takes us on a journey.

…I’m very proud of the part that sound effects had to play in that journey, in carrying us through all these phases of Oppenheimer’s life…

And I’m very proud of the part that sound effects had to play in that journey, in carrying us through all these phases of Oppenheimer’s life from the late ’20s to the mid-’60s. We’re in a lot of different locations over a span of five decades: Princeton, Washington D.C., Pasadena, Berkeley, San Francisco, and, of course, Los Alamos. Trying to give each one of those locations a specific feel was fun.

So, the whole experience was just a great fun, creative, and exciting ride for myself and my fantastic team. I learned a lot. It was just fascinating, and the fact that the film is so accurate in its detail I just find amazing. Chris is able to pull that off and explain a bit of quantum theory and also how black holes are formed all folded into a totally engrossing cinema experience. I’m fascinated by physics and always have been. And I love that Chris got all that in there and it is all dead accurate down to the smallest detail.

It was a fascinating journey and a fascinating sonic process from the beginning to the end. The track changed and evolved a great deal all the way through to the final days of the sound mix. It was a real challenge, and I enjoyed the experience a great deal.

A big thanks to Richard King for giving us a behind-the-scenes look at the sound of Oppenheimer and to Jennifer Walden for the interview!