The author who listens to the sound of the cosmos [MIT Tech Review]

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In 1983, while on a field recording assignment in Kenya, the musician and soundscape ecologist Bernie Krause noticed something remarkable. Lying in his tent late one night, listening to the calls of hyenas, tree frogs, elephants, and insects in the surrounding old-growth forest, Krause heard what seemed to be a kind of collective orchestra. Rather than a chaotic cacophony of nighttime noises, it was as if each animal was singing within a defined acoustic bandwidth, like living instruments in a larger sylvan ensemble. 

Unsure of whether this structured musicality was real or the invention of an exhausted mind, Krause analyzed his soundscape recordings on a spectrogram when he returned home. Sure enough, the insects occupied one frequency niche, the frogs another, and the mammals a completely separate one. Each group had claimed a unique part of the larger sonic spectrum, a fact that not only made communication easier, Krause surmised, but also helped convey important information about the health and history of the ecosystem.

UNIVERSITY OF CHICAGO PRESS, 2024

Krause describes his “niche hypothesis” in the 2012 book The Great Animal Orchestra, dubbing these symphonic soundscapes the “biophony”—his term for all the sounds generated by nonhuman organisms in a specific biome. Along with his colleague Stuart Gage from Michigan State University, he also coins two more terms—“anthropophony” and “geophony”—to describe sounds associated with humanity (think music, language, traffic jams, jetliners) and those originating from Earth’s natural processes (wind, waves, volcanoes, and thunder).

In A Book of Noises: Notes on the Auraculous, the Oxford-based writer and journalist Caspar Henderson makes an addition to Krause’s soundscape triumvirate: the “cosmophony,” or the sounds of the cosmos. Together, these four categories serve as the basis for a brief but fascinating tour through the nature of sound and music with 48 stops (in the form of short essays) that explore everything from human earworms to whale earwax.

We start, appropriately enough, with a bang. Sound, Henderson explains, is a pressure wave in a medium. The denser the medium, the faster it travels. For hundreds of thousands of years after the Big Bang, the universe was so dense that it trapped light but allowed sound to pass through it freely. As the primordial plasma of this infant universe cooled and expansion continued, matter collected along the ripples of these cosmic waves, which eventually became the loci for galaxies like our own. “The universe we see today is an echo of those early years,” Henderson writes, “and the waves help us measure [its] size.” 

The Big Bang may seem like a logical place to start a journey into sound, but cosmophony is actually an odd category to invent for a book about noise. After all, there’s not much of it in the vacuum of space. Henderson gets around this by keeping the section short and focusing more on how humans have historically thought about sound in the heavens. For example, there are two separate essays on our multicentury obsession with “the music of the spheres,” the idea that there exists a kind of ethereal harmony produced by the movements of heavenly objects.

Since matter matters when it comes to sound—there can be none of the latter without the former—we also get an otherworldly examination of what human voices would sound like on different terrestrial and gas planets in our solar system, as well as some creative efforts from musicians and scientists who have transmuted visual data from space into music and other forms of audio. These are fun and interesting forays, but it isn’t until the end of the equally short “Sounds of Earth” (geophony) section that readers start to get a sense of the “auraculousness”—ear-related wonder—Henderson references in the subtitle.

Judging by the quantity and variety of entries in the “biophony” and “anthropophony” sections, you get the impression Henderson himself might be more attuned to these particular wonders as well. You really can’t blame him. 

The sheer number of fascinating ways that sound is employed across the human and nonhuman animal kingdom is mind-boggling, and it’s in these final two sections of the book that Henderson’s prose and curatorial prowess really start to shine—or should I say sing. 

We learn, for example, about female frogs that have devised their own biological noise-canceling system to tune out the male croaks of other species; crickets that amplify their chirps by “chewing a hole in a leaf, sticking their heads through it, and using it as a megaphone”; elephants that listen and communicate with each other seismically; plants that react to the buzz of bees by increasing the concentration of sugar in their flowers’ nectar; and moths with tiny bumps on their exoskeletons that jam the high-frequency echolocation pulses bats use to hunt them. 

Henderson has a knack for crisp characterization (“Singing came from winging”) and vivid, playful descriptions (“Through [the cochlea], the booming and buzzing confusion of the world, all its voices and music, passes into the three pounds of wobbly blancmange inside the nutshell numbskulls that are our kingdoms of infinite space”). He also excels at injecting a sense of wonder into aspects of sound that many of us take for granted. 

It turns out that sound is not just a great way to communicate and navigate underwater—it may be the best way.

In an essay about its power to heal, he marvels at ultrasound’s twin uses as a medical treatment and a method of examination. In addition to its kidney-stone-blasting and tumor-ablating powers, sound, Henderson says, can also be a literal window into our bodies. “It is, truly, an astonishing thing that our first glimpse of the greatest wonder and trial of our lives, parenthood, comes in the form of a fuzzy black and white smudge made from sound.”

While you can certainly quibble with some of the topical choices and their treatment in A Book of Noises, what you can’t argue with is the clear sense of awe that permeates almost every page. It’s an infectious and edifying kind of energy. So much so that by the time Henderson wraps up the book’s final essay, on silence, all you want to do is immerse yourself in more noise.

Singing in the key of sea

For the multiple generations who grew up watching his Academy Award–­winning 1956 documentary film, The Silent World, Jacques-Yves Cousteau’s mischaracterization of the ocean as a place largely devoid of sound seems to have calcified into common knowledge. The science writer Amorina Kingdon offers a thorough and convincing rebuttal of this idea in her new book, Sing Like Fish: How Sound Rules Life Under Water.

CROWN, 2024

Beyond serving as a 247-page refutation of this unfortunate trope, Kingdon’s book aims to open our ears to all the marvels of underwater life by explaining how sound behaves in this watery underworld, why it’s so important to the animals that live there, and what we can learn when we start listening to them.

It turns out that sound is not just a great way to communicate and navigate underwater—it may be the best way. For one thing, it travels four and a half times faster there than it does on land. It can also go farther (across entire seas, under the right conditions) and provide critical information about everything from who wants to eat you to who wants to mate with you. 

To take advantage of the unique way sound propagates in the world’s oceans, fish rely on a variety of methods to “hear” what’s going on around them. These mechanisms range from so-called lateral lines—rows of tiny hair cells along the outside of their body that can sense small movements and vibrations in the water around them—to otoliths, dense lumps of calcium carbonate that form inside their inner ears. 

Because fish are more or less the same density as water, these denser otoliths move at a different amplitude and phase in response to vibrations passing through their body. The movement is then registered by patches of hair cells that line the chambers where otoliths are embedded, which turn the vibrations of sound into nerve impulses. The philosopher of science Peter Godfrey-Smith may have put it best: “It is not too much to say that a fish’s body is a giant pressure-sensitive ear.” 

While there are some minor topical overlaps with Henderson’s book—primarily around whale-related sound and communication—one of the more admirable attributes of Sing Like Fish is Kingdon’s willingness to focus on some of the oceans’ … let’s say, less charismatic noise-­makers. We learn about herring (“the inveterate farters of the sea”), which use their flatuosity much as a fighter jet might use countermeasures to avoid an incoming missile. When these silvery fish detect the sound of a killer whale, they’ll fire off a barrage of toots, quickly decreasing both their bodily buoyancy and their vulnerability to the location-revealing clicks of the whale hunting them. “This strategic fart shifts them deeper and makes them less reflective to sound,” writes Kingdon.  

Readers are also introduced to the plainfin midshipman, a West Coast fish with “a booming voice” and “a perpetual look of accusation.” In addition to having “a fishy case of resting bitch face,” the male midshipman also has a unique hum, which it uses to attract gravid females in the spring. That hum became the subject of various conspiracy theories in the mid-’80s, when houseboat owners in Sausalito, California, started complaining about a mysterious seasonal drone. Thanks to a hydrophone and a level-headed local aquarium director, the sound was eventually revealed to be not aliens or a secret government experiment, but simply a small, brownish-green fish looking for love.

Kingdon’s command of, and enthusiasm for, the science of underwater sound is uniformly impressive. But it’s her recounting of how and why we started listening to the oceans in the first place that’s arguably one of the book’s most fascinating topics. It’s a wide-ranging tale, one that spans “firearm-­happy Victorian-era gentleman” and “whales that sounded suspiciously like Soviet submarines.” It’s also a powerful reminder of how war and military research can both spur and stifle scientific discovery in surprising ways.  

The fact that Sing Like Fish ends up being both an exquisitely reported piece of journalism and a riveting exploration of a sense that tends to get short shrift only amplifies Kingdon’s ultimate message—that we all need to start paying more attention to the ways in which our own sounds are impinging on life underwater. As we’ve started listening more to the seas, what we’re increasingly hearing is ourselves, she writes: “Piercing sonar, thudding seismic air guns for geological imaging, bangs from pile drivers, buzzing motorboats, and shipping’s broadband growl. We make a lot of noise.”

That noise affects underwater communication, mating, migrating, and bonding in all sorts of subtle and obvious ways. And its impact is often made worse when combined with other threats, like climate change. The good news is that while noise can be a frustratingly hard thing to regulate, there are efforts underway to address our poor underwater aural etiquette. The International Maritime Organization is currently updating its ship noise guidelines for member nations. At the same time, the International Organization for Standardization is creating more guidelines for measuring underwater noise. 

“The ocean is not, and has never been, a silent place,” writes Kingdon. But to keep it filled with the right kinds of noise (i.e., the kinds that are useful to the creatures living there), we’ll have to recommit ourselves to doing two things that humans sometimes aren’t so great at: learning to listen and knowing when to shut up.   

Music to our ears (and minds)

We tend to do both (shut up and listen) when music is being played—at least if it’s the kind we like. And yet the nature of what the composer Edgard Varèse famously called “organized sound” largely remains a mystery to us. What exactly is music? What distinguishes it from other sounds? Why do we enjoy making it? Why do we prefer certain kinds? Why is it so effective at influencing our emotions and (often) our memories?  

In their recent book Every Brain Needs Music: The Neuroscience of Making and Listening to Music, Larry Sherman and Dennis Plies look inside our heads to try to find some answers to these vexing questions. Sherman is a professor of neuroscience at the Oregon Health and Science University, and Plies is a professional musician and teacher. Unfortunately, if the book reveals anything, it’s that limiting your exploration of music to one lens (neuroscience) also limits the insights you can gain into its nature. 

COLUMBIA UNIVERSITY PRESS, 2023

That’s not to say that getting a better sense of how specific patterns of vibrating air molecules get translated into feelings of joy and happiness isn’t valuable. There are some genuinely interesting explanations of what happens in our brains when we play, listen to, and compose music—supported by some truly great watercolor-­based illustrations by Susi Davis that help to clarify the text. But much of this gets bogged down in odd editorial choices (there are, for some reason, three chapters on practicing music) and conclusions that aren’t exactly earth-shattering (humans like music because it connects us). 

Every Brain Needs Music purports to be for all readers, but unless you’re a musician who’s particularly interested in the brain and its inner workings, I think most people will be far better served by A Book of Noises or other, more in-depth explorations of the importance of music to humans, like Michael Spitzer’s The Musical Human: A History of Life on Earth. 

“We have no earlids,” the late composer and naturalist R. Murray Schafer once observed. He also noted that despite this anatomical omission, we’ve become quite good at ignoring or tuning out large portions of the sonic world around us. Some of this tendency may be tied to our supposed preference for other sensory modalities. Most of us are taught from an early age that we are primarily visual creatures—that seeing is believing, that a picture is worth a thousand words. This idea is likely reinforced by a culture that also tends to focus primarily on the visual experience.

Yet while it may be true that we rely heavily on our eyes to make sense of the world, we do a profound disservice to ourselves and the rest of the natural world when we underestimate or downplay sound. Indeed, if there’s a common message that runs through all three of these books, it’s that attending to sound in all its forms isn’t just personally rewarding or edifying; it’s a part of what makes us fully human. As Bernie Krause discovered one night more than 40 years ago, once you start listening, it’s amazing what you can hear. 

Bryan Gardiner is a writer based in Oakland, California.