AGEING EVOLUTION AGHAST : MASTER GLOBAL ESSAY

 

THE BIRDS are singing - but not for me. Just by being alive, we're locked into a process of sensory decline. Why?

In America, The National Institute of Health Reports that approximately 15 percent of Americans over the age 18 report some trouble hearing. Among those older than 75, nearly half do.

As a biologist fascinated with sound, I've tried to protect my ears, using earplugs around power tools at loud concerts. Yet my hearing loss is now worse than most of my cohort friends in their mid-50s, a quirk of my genes.

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.

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 tapped 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 ageing, at the cost of having rudimentary senses.

EVOLUTION struck a different deal for our ancestors : we live in rich 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 onward, 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.

The World Students Society thanks 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.