In 1909, a French doctor named Étienne Lombard discovered something that most people intuitively know: humans raise their voices in noisy environments. Lombard first observed the effectwhich came to be named for himat the Hôpital Lariboisière, in Paris, where he noted that his patients spoke more loudly when he filled their ears with the hiss or crackle of a deaf-making apparatus. The patients seemed to adjust the volume of their speech reflexively, and Lombard suggested that the phenomenon could be used to identify malingerersthose who were faking their hearing loss in order to collect workers’ compensation.
Lombard wrote an account of his study in 1911, for a French journal called Annales des Maladies de l’Oreille, du Larynx, du Nez, et du Pharynx. Since then, other researchers have expanded on his findings. They’ve discovered that, in noisy conditions, we do more than just amplify our voiceswe also raise our pitch and elongate our vowels, changes that make our speech more intelligible. And the Lombard effect isn’t limited to humans. Animals use acoustic signalling for many purposesto attract and court mates, to claim territory and frighten enemies, to find prey and warn others that a predator is near. But nature is noisy. Rain and wind, or a sudden cicada plague, can drown out a call, and there may be a survival advantage for animals that can make themselves heard above the racket. A wide range of creatures, from killer whales to nightingales, demonstrate the Lombard effectand, according to a recent paper in Behavioral Ecology, some fish do, too.
We may think of them as silent, but fish make many sounds that are rarely appreciated by the human ear. Clownfish chirp and pop by gnashing their teeth together. Oyster toadfish hum and blare like foghorns by quickly contracting muscles attached to their swim bladders. Croaking gourami make their signature noise by snapping the tendons of their pectoral fins. Altogether, more than eight hundred fish species are known to hoot, moan, grunt, groan, thump, bark, or otherwise vocalize. Carol Johnston, an ecologist at Auburn University, is partial to the sounds made by lollipop darters, small fish native to Alabama and Tennessee. They sound like whales, she told me.
Johnston has spent more than a decade studying sound production and sensory perception in freshwater fish. In collaboration with one of her doctoral students, Daniel Holt, Johnston recently began investigating how fish that communicate acoustically might cope with anthropogenic (human-caused) noise. It’s an increasingly common question among ecologists. As the global population booms, our planet is becoming louder. According to the United States Department of Transportation, American air and road traffic has roughly tripled since the nineteen-seventies and eighties. Lawnmowers, leaf blowers, and snowmobiles add to the cacophony on land, and the sounds of cargo ships, fishing vessels, military sonar, drilling rigs, and offshore wind farms echo through the oceans. As the world gets noisier, it becomes more and more relevant to think about how and which animals will have the capacity to adapt, Sue Anne Zollinger, a research scientist at the Max Planck Institute for Ornithology, in Germany, told me.
Johnston has spent more than a decade studying sound production and sensory perception in freshwater fish. In collaboration with one of her doctoral students, Daniel Holt, Johnston recently began investigating how fish that communicate acoustically might cope with anthropogenic (human-caused) noise. It’s an increasingly common question among ecologists. As the global population booms, our planet is becoming louder. According to the United States Department of Transportation, American air and road traffic has roughly tripled since the nineteen-seventies and eighties. Lawnmowers, leaf blowers, and snowmobiles add to the cacophony on land, and the sounds of cargo ships, fishing vessels, military sonar, drilling rigs, and offshore wind farms echo through the oceans. As the world gets noisier, it becomes more and more relevant to think about how and which animals will have the capacity to adapt, Sue Anne Zollinger, a research scientist at the Max Planck Institute for Ornithology, in Germany, told me.
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