“Project Hail Mary” Sound Designers Erik Aadahl and Ethan Van der Ryn on Creating Rocky’s Alien Language
In the blockbuster space adventure Project Hail Mary (in theaters now), a sentient rock from an alien planet introduces itself to Ryan Gosling’s science teacher-turned astronaut with a succession of growls, gurgles, clucks, chirps, and chitters. The dog-sized chunk of material, which has no face, five arms and no name until Grace anoints him “Rocky,” uses a language devised by Oscar-nominated sound designers and supervising sound editors Erik Aadahl and Ethan Van der Ryn (A Quiet Place, The Creator), who experimented for months before arriving at a vocabulary that pleased their famously exacting directors Phil Lord and Chris Miller (the script was written by Drew Goddard, adapting Andy Weir’s novel of the same name—Goddard was nominated for an Oscar for adapting Weir’s The Martian).
Like Lord and Miller, Aadahl and Van der Ryn work as a team. “Chris and Phil might not always agree on something, but that forces them to find something better than what either one of them would have done on their own,” says Aadahl. “In a way, their relationship as directors is very similar to ours, where there’s a kind of alchemy that creates something better than the sum of the parts.”
Speaking from their studio in Burbank, California, Aadahl and Van der Ryn describe the ancient instruments, whippoorwill cheeps, jugs, and other ingredients that shape Rocky’s alien speech.
Audiences are turning out in droves for Project Hail Mary—a feel-good movie about the future!
Erik: How rare is that? It feels like it’s needed. It feels like the right time.
What was your creative brief from directors Lord and Miller?
Ethan: Let me start by saying that I read Andy Weir’s [2021] book and saw that this alien creature language is musical, literally scripted in quotations as quarter notes and eighth notes. I was trying to decode what that would sound like and thought, “Man, whoever winds up doing the movie of this book is gonna have their job cut out for them.” Flash forward to us being invited to be the sound designers on Project Hail Mary. I was like, “All right, here we go!”
Erik: The alien’s music-based language uses tones and harmonies. When Rocky gets more agitated, his pitch goes up; when he’s more grave and sincere, his pitch goes down. There was one description saying his deeper notes were “whale” so we used the humpback whale, and then the higher notes could go up into the piccolo range. We started with reed instruments because they can be expressive, allowing Phil and Chris to direct us in our performance of these things in the same way he would direct actors. But then we wound up jettisoning most of the reed instrument lexicon.
Why?
Erik: They didn’t go for the piccolo.
Did you use any electronic elements?
Ethan: No. A strong part of Chris and Phil’s brief was not to have it be electronic at all, so we purposely stayed away from all electronic sounds. But what we found is that some of the most organic sounds, for instance, bird calls, can feel electronic. We’d be reviewing a scene, and Phil would say, “That sounds too electronic,” and we’d be like,” Oh, that’s just a whippoorwill.”
Ethan: When you play some of these organic sounds out of context, they start to feel a little electronic. There’s no rhyme or reason for it.
Erik: The direction from Chris and Phil was that they wanted it to sound like there was a film crew on the ship, capturing these things as if it were a nature documentary. All of Rocky’s sounds needed to feel like they were coming out of him naturally. We found that flute-based instruments had a natural breath to them, and even found a flute inventor who came up with a bunch of different types of instruments, but ultimately, the winner was an ocarina, which you hear a lot in this movie.
The ancient potato-shaped instrument made from clay?
Erik: Yeah. The ocarina has an exotic note structure and a breath that feels very alive. To bring even more aliveness, we had one of our sound designers, Dave Whitehead, place transducers on slabs of granite to enhance resonance. Then we rerecorded it to add another layer of realism, as if the sound were coming from this carapace of heavy stone. Ethan and I love to experiment in that way to see how deep we can go.
In building the language, did each tone have a specific meaning throughout the film, or was it more random?
Erik: Rocky’s Eridian language includes 250 words and concepts he uses in the film. Our lead assistant kept a database: “What are the most used words, what are the least used words?” At the end of the process in the mixing stage, Chris might go, “Rocky’s word for ‘sleep?’ Let’s try some different options.” So then we’d create new words for “sleep,” choose one, and apply it at 34 minutes into the movie, 56 minutes into the movie, and again at 87 minutes into the movie.
Ethan: We didn’t take any shortcuts. Whether it’s a gurgle, a tone, or a combination of tones, we wanted it to be an actual living, breathing language.
Erik: One of the first words we really wanted to lock down was “Question” because in English, if you have a question, you might just raise the pitch on the last note, like, what is your name? implies a question, right? Rocky would literally say “question” at the end of a question. For that, his word was… [Erik makes a fast-rising clucking sound].
Smooth.
Ethan: And Rocky says the word “question” in dozens of different ways, depending on the context, so it might be deeper when he’s very serious. It might be a jug.
A jug?
Erik: Yes, an earthenware jug that Chris brought to the studio one day. He said, “I have a gift for you guys,” and went into his trunk, pulling out a big jug. You fill it with water to different levels to get different pitches out of it. And that’s what we performed here in the studio, to get some of the bass notes.
Ocarina, jug… what were some other instruments behind Rocky’s “voice”
Erik: The performed musical instruments would include the jug, ocarina, didgeridoo, contralto flute, and contralto clarinet, for when he’s more agitated. And then there’s the animal world. My favorite is the solitaire bird, which is one of the ingredients in the word for the name “Rocky” in his Eridian language.
Ethan: Avian brains are a lot quicker compared to our brains. If you record birdsong at a high resolution and slow it down, you get so much information in every second—there’s such a beautiful, invisible world in there.
Erik: And that’s part of the fun of being a sound designer: you can delve into that secret sonic world of nature and then use it in a movie that deserves it.
Rather than being a CGI creation, “Rocky” is a physical puppet on set, operated and eventually voiced by puppeteer James Ortiz. Were you guys also on set, “performing” the alien sounds?
Erik: No, that all happened in post-production.
On a tangent here, Erik and Ethan, why are you a team? Typically, there’s one single department head in charge of sound, whereas you two collaborate as equal partners. How did that happen?
Ethan: We met on Transformers, so we’ve been working together for twenty years. I think the reason it’s lasted so long is that we have a very similar aesthetic. We like to do the really hard stuff, and we want to give ourselves goosebumps. We have no fear of throwing away work if it’s not hitting that [level].
Being based in L.A., are you mindful of the impact that post-production on a big movie like Project Hail Mary can have on the local filmmaking economy?
Erik: 100 percent. The past few years have obviously been rough, with so much production moving out of LA and out of state, mostly for tax-rebate reasons. It’s been affecting everyone, but we’re hopeful that something can be done, at the state and federal levels, to make it more economically competitive for shows to stay here. Fortunately, all of the post-production on Project Hail Mary was done here in Los Angeles. Our studio is based in Burbank, so sound design was done here, and all mixing was done at Sony in Culver City.
You guys immersed yourselves in the world of Project Hail Mary for months. What’s your takeaway from that experience?
Erik: At its core, Project Hail Mary is about communication, and sound is communication. It’s how we connect as humans, how we understand each other, how we can truly empathize and collaborate and work together to make a better world. I love the optimism in this story where sound is the centerpiece of that noble endeavor.
Project Hail Mary is in theaters now.
Featured image: Ryan Gosling stars as Ryland Grace in PROJECT HAIL MARY, from Amazon MGM Studios. Photo credit: Jonathan Olley © 2025 Amazon Content Services LLC. All Rights Reserved.
