Last summer, Greg Smith was standing in front of a Home Depot when he got an unexpected phone call. When he answered, the voice of NASA astronaut Kjell Lindgren greeted him on the other end. "I said, ‘Oh! You’re down!’ and he said, ‘No, I’m up here,’" Smith recalls. "He had called me from space."
More specifically, Lindgren had called from the International Space Station (ISS), where he was to remain for five months. Smith, a professor at the Savannah College of Art and Design (SCAD), has for the last 25 years trained NASA’s astronaut crews in the use of IMAX recording equipment on board the shuttle and ISS. He'd worked with Lindgren before, and the two had become friends. "We were just shooting the breeze," Smith says. In other words, an astronaut had called him from 200 miles above Earth just to say hey. "I gotta tell you, there’s nothing like getting a call from space," Smith says.
When Smith hung up, he couldn’t stop thinking about the call. At SCAD, he was teaching a class called Production Audio, teaching graduate students about the importance of ambient sound in films. As he thought about Lindgren in the vastness of space, he had an idea: "It hit me like a bolt," he says. "Why don’t we record some sounds for him? When you’re floating around in space, you’re looking at pictures of friends and family and things on Earth, but there’s an audio component missing."
So Smith decided to turn his idea into a classroom experiment. He told his students to record ambient Earth sounds (some of which we've converted into SoundCloud files here), from rain falling to waves crashing to street traffic. The students created about 20 sounds in total, and Smith worked with NASA to have them compressed and uploaded to the ISS, where Lindgren was waiting.
"It was a lot of fun to hear the sounds that Greg’s students had captured," Lindgren told Fast Company. "Sounds of the water, by the ocean, sounds of kind of a busy street corner. Those are things that are very familiar, so I would just sit in my crew quarters with my headphones on and listen to those sounds."
Sure, astronauts like Lindgren could probably find recordings of Earth noise elsewhere, on YouTube or SoundCloud, but these were created specifically with them in mind. Some of the files are long as well, with up to 10 minutes of high-quality, uninterrupted sound.
To prevent astronauts from getting homesick, NASA makes sure they can communicate regularly with friends and family via video conferencing. It’s also been investing in virtual reality projects that could "trick the brain and make people feel as if they are in a variety of beautiful and calm settings, such as with their family at home or strolling on the beach," Lorie Loeb, director of Dartmouth's Digital Arts Leadership and Innovation lab, explained in a news release. Astronaut Scott Kelly has a special Spotify playlist to keep his spirits high.
When it comes to noise, astronauts on the ISS are constantly exposed to the not-so-soothing sounds of a hunk of machinery soaring through space, which Lindgren describes as a low rumble. "Fans and pumps are operating constantly in the background," he says. "It’s just part of life up there."
But what could the constant hum of a space station do to one’s mind, and sense of homesickness? According to sound consultant Julian Treasure, humans find the natural sounds of Earth soothing. As he explained in a TED talk, ocean surf, for example, "has the frequency of roughly 12 cycles per minute. Most people find that very soothing, and, interestingly, 12 cycles per minute is roughly the frequency of the breathing of a sleeping human. There is a deep resonance with being at rest. We also associate it with being stress-free and on holiday."
Treasure told Fast Company that disconnecting from natural sounds like wind, water, and birds could widen the perceived disconnect between the astronaut and home. "We’ve evolved to them over hundreds of thousands of years, and we’re in some way used to them," he says. "I think it’s very wise for this professor and his students to have recorded sounds of Earth for the astronaut so they can feel more comfortable, less far from home. Goodness, they’re the farthest from home of anybody."
Smith hopes to do more unique projects like this with his future classes at SCAD. "Being able to share something like this with the students was thrilling," he says. "You go home, and mom and dad ask what you did in class this quarter. Now the kids can say, ‘We sent sound effects up to space!’ I thought that was really cool."