Science Friday - How a sound designer gave an alien its voice (and 250 words)

Episode Date: April 10, 2026

Movies may be a largely visual medium, but sound plays a huge role in setting tone, creating new worlds, and fleshing out characters. Sound designer Erik Aadahl has brought some of Hollywood’s iconic creatures to life with sound, like the Transformers, 2014’s Godzilla, and Rocky the alien from “Project Hail Mary.” He joins Flora to talk about the science of sound design, and how he uses his background in biology to look for sounds in the animal kingdom. Guest:  Erik Aadahl is a sound designer and editor at E² in Los Angeles, California. Transcripts for each episode are available within 1-3 days at sciencefriday.com. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Hey, I'm Flora Lickman, and you're listening to Science Friday. A few weeks ago on the show, we talked about the sci-fi space exploration movie Project Hail Mary. And I was particularly obsessed with the sounds that the alien in the movie Rocky was making. They're distinctive and they're funny and Rocky talks a lot. And so I asked Andy Weir, who wrote the book Project Hail Mary and who's a producer. on the movie if the sound designers actually made a real language for Rocky, like if it was internally consistent.

And here's what Andy said. I don't think so. I'm so disappointed. I didn't get the answer I wanted, but then, almost like in a movie, we got this very surprising message on our listener line. Hello, Science Friday. This is Eric Adol calling from Los Angeles, California. I'm a long-time listener, and I recently enjoyed your interview with Andy Weir and Dr. Wong about the science of Project Hail Mary.

A question came up about the sound design of Rocky's alien language, and as the sound designer of Project Hail Mary, I'm in a unique position to answer. Love your show. Keep up the good work. Eric is not just the sound designer behind Project Hail Mary. He also did sound on 2014's Godzilla, Transpherson. and a quiet place. And he's here to tell us all about the art and science of making movie monster roars and more. Eric Adolph, thank you for being here. It's a pleasure to be here. I'm genuinely so happy you called us. This is like the center of my nerdiness. It seems like the best job. Is this the best job? Well, I don't have too many frames of reference, but yeah, I would say it is one of the the best jobs I can imagine.

Are you that person at the restaurant who's like always listening? Like, are you like, shh, guys, I hear an interesting teacup clink and I must capture it. Like, are your ears always on? Yes, my ears are always on. Though at restaurants, I'm usually trying to filter out all of the noise. But when I'm just going about my daily life, you know, if I open a door and it creaks in a weird way, I think, okay, got to go grab. my rig, record that. If there's an exotic bird that shows up in my yard, got to get the rig, record that. One of the nice benefits of my job is it does kind of open up your awareness to

experience. And so I try to always be aware of what is happening sonically around me and then maybe worry later about how I might be able to use that in a movie. Well, let's talk about one of your movies. Project Hail Mary, we have to talk about the alien Rocky's voice. As I said, this is like a thing I'm obsessed with. So for people who haven't seen it, here is Rocky saying his name in his native tongue. That's beautiful.

Yeah. And that scene, that's one of my most enjoyable little moments because Rocky's saying his Eridian name for the first time to Dr. Grace. And then Dr. Grace asks him, well, you know, what's my name? What's your name for Grace? and it's just like a burp, you know.

So Rocky has a much more elaborate version of himself. And the way that was directed by Chris Miller and Phil Lord was they asked for something that was sort of beautiful and proud. And you could imagine he's saying, you know, I am Rocky from the bolder, rough textured hills of X, Y's. You know, like it's a long kind of epithet. But yeah, that was a fun moment where he could kind of open up with his expressiveness. Can we hear it one more time? Okay, clearly multilayered. What sounds are in there making up that voice?

So let's go from the lower frequencies to the higher frequencies. So the bass kind of note there is a didgeridoo, and that's creating kind of our bass notes. And so that's what we performed for that. And when you get into the more gurgly layer, there's some humpback whale. There's also some avian species. And one of my, there's a class of birds, thrushes that have just the most beautiful song. And that sound that we just heard for Rocky's name has a solitaire bird. And we slowed it down by a couple of octaves to get it into a more musical register that works better for the human ear.

And that's the kind of melodic center of Rocky's name for himself. Were there any other ingredients that you used in his vocalizations? For most of his communication when he's calm, We used an okarina. What is that? It's like a simple wind instrument and sounds kind of like this. And that could be pitched. You know, we record at high resolutions, 192 kilohertz,

way above human hearing range. And we can slow it down without losing any fidelity into a nice five, six octave range. He does get a little bit impatient and more agitated and or, annoyed with Dr. Grace. And for that, we used contralto clarinet, which has a nice, like, a little bit more, you don't,

you know, it sounds like an animal, but a little more edge. A little more edge to it, a little rasp to it. You know, it's funny, with certain sounds, you can close your eyes and you can put a label to it, like, oh, that sound sounds annoyed, or

that sound sounds content. That clarinet is annoyed. It's a little pissy. It's amazing. I mean, it's almost like you have to be a wildlife biologist and also a musician of many instruments to do this job. I am a musician and I did double major in biology and cinema in college. It really does show. I mean, how does the recipe come together?

Like when you're putting together rocky sort of, you know, language. or vocalizations. Are you like, oh, man, I need a pinch of humpback wailed or really, you know, complete this? Is it like cooking or is it something different? Yeah, it's a little bit like cooking. It's a little bit like knitting. And I think of it a little bit like painting, you know, colors being frequencies. And you try to be very specific with what sound frequencies you use because like painting, it can very, quickly become muddy. The ideal is simplicity. You know, if you can be simple and bold, that's kind of the ideal. So first, we wanted to just figure out what is his voice. You know, the, the voice conveys the soul and the spirit. And then once that was figured out, then we got

into the nitty-gritty of his erudian language, which we wanted to be accurate with. We wanted the word for sleep in this section to be consistent with sleep later, but there might be a different context. And so it might be performed a little bit more intensely or a little bit more calmly or quickly or slower, depending on the context. So. Oh my gosh. So the language is actually consistent throughout. The language is consistent. Correction. Yeah. Yeah. He's got, there's about 250 scripted words for Rocky. So the sleuths out there who want to go do some forensic sound examinations can probably spend a year trying to parse all that out. Well, you, like you said, the sound brings Rocky to life. And it's a huge part of the movie.

I think it's, to me, it's half of the cinematic experience. You know, we use our eyes and we use our ears. And in a way, our ears can manipulate emotion more powerfully and a more sublimit. way. You think so? I think so. I mean, well, you know, just the way sound works on our brains is it goes through our medulla oblongata first before it hits the auditory cortex. And that's where you get things like pitch and localization and sound level power intensity. That's all pre-thought. You know, a brilliant filmmaker once said that sound kind of comes in through the back door. and images come in through the front door. And in a way, that gives us a lot of power over how to express emotion and evoke emotion in an audience.

So, yeah. We have to take a break, but when we come back, we have to talk about another iconic movie creature vocalization that you hooked up. If you know, you know. Let's talk about Godzilla. Okay. So let's go back to 1954. This is the original Godzilla Roar. Classic.

Iconic, yeah. Eric, you were tasked with making an updated Godzilla Roar for the 2014 movie. Because that's an iconic movie and an iconic sound, did it feel like a lot of pressure? Well, yeah, there's pressure to it, you know, because it's a piece of cinema history. And it's so iconic that you can play that sound anywhere around the music. worlds and people close their eyes and they know that's Godzilla. So we definitely needed to pay homage to that. And the director, Gareth Edwards, he was like, you know, we can't really use that 1954 recording. When you put that in a theater, it sounds kind of old. It's a little

vintagey. A little dusty, yeah. Yeah, a little dusty. How do we do that, you know, with the technology we have 70 years later. And so that that led into four months of experimenting. Wow. And I wanted a sound that just felt like an anthem that I could fill the theater with in Dolby Atmos and just, you know, my barometer is always, am I getting goosebumps or not? And if I don't, I'm like, okay, I need to keep experimenting, keep trying stuff. And it, and it, sometimes, it's very serendipitous how this works. There's happy accidents that weren't intentional. And for something, you know, different, I was recording a lot of different sounds using dry ice.

So you've got basically frozen carbon dioxide gas. It's very cold. And you can use it against different metals. Usually metals are the most interesting things to apply to dry ice. And on the Foley stage, we had this. six-foot-long cylinder. It was a piece of, like, air conditioning, ducting, and just put that on top of this block of dry ice, and it started resonating.

And, you know, because the dry ice is cooling the metal, the metal is now condensing and vibrating in doing so. And that vibration starts to push air. And it just started doing this whale. And I thought, okay, wait, there we are. That I can use as sort of the central ingredient for the new roar, and hopefully it translated. Let's hear it. And, you know, it is funny.

The inhale before he does the roar is that's an elephant blowing through his trunk. And it was Michael Jackson's former elephant bow. and her partner, Susie, who are now living on a refuge in Lancaster, California. And the way you get elephants to trumpet, they trumpet when they're happy, is to let them go to the pond. And so they were basically stampeding when they did that. And so the trick is to mic them in a way where you're not hearing tree branches snapping and, you know, get a nice clean.

trumpeting sound and or or a trunk you know raspy trunk sounds so where you're just like hi i need hi hello elephant sanctuary i must come mike your like your elephants uh yeah yeah one of our assistants reached out and they were totally into it so okay before we go i want to play a game with our listeners we're going to play a sound from the terence mallock movie the tree of life. And this particular sound is the sound of the universe expanding, which also sounds like a hard assignment, just as an aside. And, okay, everybody listening, I want you to think about what this sound could be. Is it a ghost, Eric? I have not been able to record a ghost yet. But yeah, so for the entire real two of the tree of life is kind of a 20-year.

minute us witnessing evolution of the universe from the very beginning, from the Big Bang, through creation of stars and planets and evolution of life on Earth through different periods. And obviously in space, we're working with a vacuum. So using sound in space there was more to create a feeling. It wasn't necessarily intended to be literal. It was more to evoke kind of vastness and mystery and maybe loneliness. And Terrence Malick had kind of asked us to just go with your instincts and we'll see. And I did not tell him what it was. He asked me. And I've learned this over many years. It's not always a good idea to tell a director what the sound is, you know, because sound is, it's a very abstract art.

You're often using something that has nothing to do with what you're witnessing visually on screen. And that's part of the malleability of sound and the expressiveness of sound is you can be very abstract with it. And he said, well, okay, don't tell me until we're done. But I'm going to name it, and he named that the sound of eternal silence. So that's what in my personal... It's perfect, right? I mean, sometimes you need a poet to apply words to sounds because sounds can be very hard to describe. So I thought that was very poetic.

And when we were done, I told them what it was. And that was me breathing into a microphone. Sometimes the answer is. right in front of you or in you. Literally. Thank you for what you do, Eric. Well, thank you for listening. Eric Adol, the sound editor and designer behind many of your favorite movies and apparently

a Science Friday listener. This episode was produced by Kathleen Davis. And if you liked the sound of this podcast, or maybe something didn't sound right, or maybe you too are a sound designer behind some of our favorite movies. Call us and let us know, 8774-4-s-eye-fry. 8-7-7-4-Sy-fry. We'll catch you next time. I'm Flor Lichtenen.