Humanity’s noise is the natural world’s enemy It’s time to quieten down so that other species can thrive

People have profoundly altered the planet’s soundscape

Natural History of Silence Jérôme Sueur Polity (2024)

“Shhh!” This is the demand that eco-acoustics researcher Jérôme Sueur makes of humanity. The racket of technology — emanating from ships, aeroplanes, machinery and more — permeates even the remotest corners of the planet.

Sueur explores the impact of this ever-present hum on the animal world in Natural History of Silence. He offers rich descriptions of the sonic lives of several species, such as the rhythmic mating chirps of cicadas and the crackling and popping sounds produced in coral reefs. When human-made noise drowns out nature’s symphony, ecosystems become disrupted, Sueur argues. For instance, experiments around Moorea Island, French Polynesia, show that motorboat noise upsets free-swimming juvenile corals, which rely on reef sounds to find a suitable place to settle. In quieter, protected areas, coral attraction to reefs is much higher (D. Lecchini et al. Sci. Rep. 8, 9283; 2018).

Anyone new to the science of sound will be able to learn its foundations in this book. Sueur explains how animals create, use and perceive sound and how researchers have used this knowledge to understand wildlife behaviour. Tucked between travelogue-style chapters and wandering philosophical ruminations, there is a primer on key terms and theories, such as the acoustic niche hypothesis, which posits that each species has a unique acoustic space to enhance communication with its peers and limit sound competition from other species. The book also includes an abridged evolutionary history of how animals developed the ability to send and receive vibrations.

Be silent and tune in

Sueur’s thesis is this: silence is a crucial resource, like food or water, that species compete for to survive. “Making sound is an essential part of being alive,” he writes. But humans need to “make sure we are not more alive than others”.

Sueur offers practical advice on how to do that. A student of writings by naturalist John Muir and poet Walt Whitman, he encourages readers to seek solitude in a remote location to grasp the profound value of turning the noise dial down. Be silent and tune in, he writes, for a naturalist’s meditation focuses on the external rather than internal world. The book starts with one such excursion — a winter walk in the Chartreuse Mountains in France — where, Sueur writes, “for the very first time, I experienced silence in a natural world teeming with life”.

Birds (such as the white-crowned sparrow, pictured) need to sing louder to be heard over the noise of nearby traffic.Credit: Kurt Stricker/Getty

The book’s central theme revolves around the concept of Umwelt, a word used by German biologist Jakob von Uexküll to refer to the sensory world unique to each species, shaped by its sensory organs. An animal’s Umwelt is the limited slice of the world it can perceive and defines its immediate environment. Sueur suggests that constant noise disrupts many species’ perception of the world and hinders people’s ability to have empathy for others. Because noise “gets in the way”, it secludes us from the natural rhythms of the ecosystem.

The Risoux forest, a protected area in the Jura Mountains that straddles the border between France and Switzerland, is a prime example. There, hazel grouse (Tetrastes bonasia) and Eurasian pygmy owls (Glaucidium passerinum) fly, and so, too, do planes in a “physiological and psychological assault which is repeated every five minutes”, Sueur writes. “Up there, the airline companies, the pilots, the tourists, sometimes including ourselves, are in the process of contaminating an entire forest without realizing it and are passing by without even a gesture of apology.”