If you had to forfeit one of the five human senses, which one would you choose? If you chose “hearing,” Michael Stocker’s new book Hear Where We Are: Sound, Ecology, and Sense of Place may cause you to reconsider. A comprehensive study of sound perception, Hear Where We Are makes the case for how utterly dependent we are on the “sounds of our environment to reveal the hidden dimensions of our reality.” Here’s Michael on how hearing—among humans and nonhumans—can do more than simply gather information.
When we humans ponder the perceptual adaptations of other animals, we typically do so through the lens of our own priorities. As a visual metaphor, the use of a “lens” does not sound too myopic, as we see lenses as implements that bring our vision into focus. But in the realm of hearing, the “ear-trumpet” might be our best-fit metaphor: ear-trumpets allow the user to hear what they want by excluding the sounds that they don’t.
It has been by way of the ear-trumpet that much of our scientific inquiry takes place—by excluding noise we arrive at the essence of what we are seeking. Visual noise is clutter; we seek to fix our gaze on what is useful. The prize of our inquiry is the vision we behold.
But this is not necessarily the case with other animals. Auditory “noise” is not necessarily clutter; it can be rich in information and context, particularly for animals that live in the dark—in deep earthen warrens, within the obscuring haze of seawater, or under the cloak of night. For these animals, sound allows them to reach out and weave themselves into the fabric of their environment, sensing movements of predator and prey, and perceiving the safe or threatening boundaries of their surroundings.
Crickets and cicadas provide good examples. Both insects synchronize their calls to create an acoustic community, bonding them to kin but ambiguating their individual locations to predators. Chameleons, too: they tremulate into their perching branches to secretly let other chameleons know where they are—a technique used by elephants to communicate through the earth to conspecifics located miles away but unheard by human predators nearby. Also in this acoustical realm, certain fishing bats echolocate their prey by reflecting bio-sonar off the surface ripples the fish leave in their wake. And some fish perceive their nocturnal surroundings illuminated by the crackling hiss or “acoustic daylight” provided to them by the ubiquitous snapping of pistol shrimp.
While we humans can take our finely tuned instruments into these various settings, we can only derive numbers—which we can try to convert into understanding. But if we take the ear-trumpet out of our ears and listen to our surroundings—how the music of the dawn chorus has a certain groove to it, or how the shifting phases of the locust’s incessant buzz sounds like the wind blowing through the trees—we may arrive at a deeper understanding of our place and the voices around us.
In writing Hear Where We Are: Sound, Ecology, and Sense of Place, I was able to indulge myself in the auditory sensuality of my surroundings. Stepping back from the metrics of “speech intelligibility indexes” and “auditory thresholds,” I was able to reawaken the larger share of my sense of hearing—the part that allows me to perceive what is out of my grasp, downwind from my sense of smell, and obscured from the perimeter of my vision. In this way, I find that we are not much different from the animals we try to understand through our various measurements. I find that, in addition to being able to convey ideas through words and language and music, much of our sound perception also allows us to hear where we are.
Michael Stocker is the founding director of Ocean Conservation Research, which explores the effects of noise pollution on the world’s oceans.