By Elena Kazamia

In a modest rectangular enclosure surrounded by sparse green shrubbery, just past the main gate of San Diego Zoo Safari Park, a middle-aged hyacinth macaw blasts Daft Punk on his bespoke boombox. His name is Sampson and he likes to dance.

Sampson can operate the boombox, aptly named JoyBranch, by biting or holding on to a kind of joystick made to look like a slice of log with a twig protruding from it. Motion sensors (called BobTrigger) keep the music going as long as he bobs and nods, dipping his head in rhythm. Within weeks of its installation, the boombox changed the dynamics of Sampson’s interactions with visitors. To draw them in, he could rock out. When he tired of entertaining, he could stop dancing to switch off the music. More often than not, when the show was over, his visitors moved on.

JoyBranch is one of a number of sound projects at San Diego Zoo and other zoos around the country that aim to give captive animals more agency over their environments. The boombox came into being after Sampson’s caretakers noticed how much the bird enjoyed grooving to the rhythms wafting from an iPhone during care sessions. (The BobTrigger was added when they realized he couldn’t press play on the JoyBranch and dance at the same time.)

The project was led by Rébecca Kleinberger, a digital technology, cognition, and sound researcher trained in MIT’s Media Lab who now runs her own research group at Northeastern University in Boston. When Kleinberger walks through a zoo, she doesn’t just look, she listens. Here is the cackle of families laughing and talking as they walk by, a gasp of excitement as an animal turns to face them, a child’s piercing cry for attention. Then the sound wave of human noise retreats as the crowd moves on, and she can suddenly detect the roar of a male lion in the distance. It is a deep, penetrating, regal growl that visitors delight in. But how does it make the gazelle standing just a few feet away from her behind the slim barrier feel? The animal is evolved to feel fear.