Animal sounds are my connection to the changing seasons. Every week, a new voice appears or fades. Early winter arrives with the chip of juncos. The chitter of nestling bluebirds signals the onset of summer, closely followed by the first cicadas.
This year, though, the yearly cycle was missing a voice. In that absence, I learned something about my creeping deafness and, beyond, the Faustian bargains that our ancestors struck with evolution.
Where I live in the Southeast, late spring is marked by the songs of blackpoll warblers, tiny black-and-white birds migrating from South America to the boreal forests of Canada where they breed. They’re here for a week just as the school year ends and tomato-planting season begins, a joyful time. This year, I heard none. My partner, though, could hear their high-pitched song and pointed the birds out as they flitted in the treetops.
The sonic erasure felt deeply unsettling. I could hear other everyday sounds — passing cars, cardinals whistling, neighborhood kids at play — but the blackpoll’s song was gone.
Graphs from my audiologist show hearing loss across all sound frequencies, but especially for high sounds, so I was expecting this moment. Still, the loss of blackpoll warblers hit me hard. I had looked forward all winter to hearing them and then … nothing. Now, in summer, I notice other gaps in the soundscape, especially the high, raspy thrumming of the meadow katydids. This is a strange grief: The songs are there, but not for me. I miss them.
As a biologist fascinated with sound, I’ve tried to protect my ears, using earplugs around power tools and at loud concerts. Yet my hearing loss is now worse than most of my cohort of friends in their mid-50s, a quirk of my genes. I’m not alone. The National Institutes of Health reports that approximately 15 percent of Americans over the age of 18 report some trouble hearing. Among those older than 75, nearly half do.
We can lose hearing in many ways. Eardrums, middle ear bones and nerves can falter, as can auditory processing in the brain. For many people, loss of function in hair cells in the inner ear are to blame. These cells amplify the motions of sound waves in the inner ear, and then turn the motion into nerve impulses.
The hair cells in our ears are descendants of the wiggly cilia hairs that animate single-celled creatures swimming around in ponds and ocean water. These cilia enable hearing throughout the animal kingdom, from vibration-sensitive organs in the skin of fish to sound detectors in the legs of insects.
Sudden shocks like gun blasts kill inner-ear hair cells. Other losses take time, like prolonged exposure to loud noise. Some pharmaceutical drugs can kill hair cells. But much of the loss has little to do with assaults from the outside. Instead, aging undermines hair cells. Even a life spent drug-free in quiet surrounds would not protect our ears from the erosive power of passing years. Once gone, the cells never grow back or heal.
Just by being alive, we’re locked into a process of sensory decline. Why?
Every sensory experience is mediated by cells. Cells accumulate defects over time, eventually slowing or ceasing their work. And so, to experience the passage of time in an animal body is to experience sensory diminishment. The only animals known to have broken this deal with time are relatives of jellyfish called hydra. Their bodies are sacs topped by tentacles. Their nerves are woven into a net, with no brain or complex sense organs. This simple body lets hydra regularly purge and replace defective cells. These eternally youthful inverted jellyfish live seemingly without aging, at the cost of having rudimentary senses.
Evolution struck a different deal for our ancestors: We live in richly sensual bodies, but are too complex to be ageless.
We can, though, partly break the deal. Sensory experience is about attention as much as it is about the physiology of cells. The undergraduate students in my field biology class generally have ears that can pick up more frequencies than mine. Yet when we go outside, I hear more. At least at first. I invite students, regardless of hearing “ability,” into what the philosopher Simone Weil called the “rarest and purest form of generosity”: attention.
We listen through our chests for low hums and percussive beats. We rest fingertips on twigs to perceive how wind converses with wood. We send our bodily attention outward, using ears, palms, soles, guts and muscles.
What we find differs among us in its tones and textures. We connect to stories of the world around us, carried in sound’s many pulsations. We share these stories, listening through one another’s perceptions. We name bird, insect and frog species, and hear the diversity of human voices. We study the energies of traffic and buildings. We follow vibrations back to their sources, some beautiful and life-affirming, like the music of other species, and others broken, such as excessive and unjust noise.
With repetition, sensory attentiveness works its way into everyday experience. I paradoxically listen more and with greater pleasure than in previous years, even as my inner ear hair cells die off. Doing so with other people helps. I find the blackpoll warbler through the ears of my companions. I share with others what my listening has taught me. Take that, hydra.
Opening our senses to the living world does not erase the sorrows of aging. But paying attention in community can bring delight in the moment, and is a defiant and joyful answer to evolution’s bequest.
David George Haskell, a professor at the University of the South, is the author of “Sounds Wild and Broken: Sonic Marvels, Evolution’s Creativity, and the Crisis of Sensory Extinction,” a 2023 Pulitzer finalist.