Chapter 9. Hearing, Vestibular Perception, Taste, and Smell

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By VERONIQUE GREENWOOD Ears are a peculiarly individual piece of anatomy. Those little fleshy seashells, whether they stick out or hang low, can be instantly recognizable in family portraits. And they aren’t just for show. Researchers have discovered that filling in an external part of the ear with a small piece of silicone drastically changes people’s ability to tell whether a sound came from above or below. But given time, the scientists show in a paper published Monday in the Journal of Neuroscience, the brain adjusts to the new shape, regaining the ability to pinpoint sounds with almost the same accuracy as before. Scientists already knew that our ability to tell where a sound is coming from arises in part from sound waves arriving at our ears at slightly different times. If a missing cellphone rings from the couch cushions to your right, the sound reaches your right ear first and your left ear slightly later. Then, your brain tells you where to look. But working out whether a sound is emanating from high up on a bookshelf or under the coffee table is not dependent on when the sound reaches your ears. Instead, said Régis Trapeau, a neuroscientist at the University of Montreal and author of the new paper, the determination involves the way the sound waves bounce off outer parts of your ear. Curious to see how the brain processed this information, the researchers set up a series of experiments using a dome of speakers, ear molds made of silicone and an fMRI machine to record brain activity. Before being fitted with the pieces of silicone, volunteers heard a number of sounds played around them and indicated where they thought the noises were coming from. In the next session, the same participants listened to the same sounds with the ear molds in. This time it was clear that something was very different. © 2018 The New York Times Company

Keyword: Hearing
Link ID: 24727 - Posted: 03.07.2018

By DOUGLAS QUENQUA Claudio Mello was conducting research in Brazil’s Atlantic Forest about 20 years ago when he heard a curious sound. It was high-pitched and reedy, like a pin scratching metal. A cricket? A tree frog? No, a hummingbird. At least that’s what Dr. Mello, a behavioral neuroscientist at Oregon Health and Science University, concluded at the time. Despite extensive deforestation, the Atlantic Forest is one of Earth’s great cradles of biological diversity. It is home to about 2,200 species of animals, including about 40 species of hummingbirds. The variety of hummingbirds makes it difficult to isolate specific noises without sophisticated listening or recording devices. In 2015, Dr. Mello returned to the forest with microphones used to record high-frequency bat noises. The recordings he made confirmed that the calls were coming from black jacobin hummingbirds. The species is found in other parts of South America, too, and researchers are unsure whether the sound is emitted by males, females or both, although they have confirmed that juvenile black jacobins do not make them. When Dr. Mello and his team analyzed the noise — a triplet of syllables produced in rapid succession — they discovered it was well above the normal hearing range of birds. Peak hearing sensitivity for most birds is believed to rest between two to three kilohertz. (Humans are most sensitive to noises between one and four kilohertz.) “No one has ever described that a bird can hear even above 8, 9 kilohertz,” said Dr. Mello. But “the fundamental frequency of those calls was above 10 kilohertz,” he said. “That’s what was really amazing.” © 2018 The New York Times Company

Keyword: Hearing; Animal Communication
Link ID: 24725 - Posted: 03.06.2018

By Virginia Morell A dog searching for a lost child is typically given an item of clothing to smell. But what does that scent “look” like? To find out, scientists tested 48 dogs, half of which had special police or rescue training. In a laboratory room, the scientists slid each dog’s favorite toy across the floor to a hiding place, while the dog waited in another room. One researcher then brought the dog to the testing room and pointed at the starting point of the odor trail and told the dog, “Look for it! Bring it!” In one trial, the dog found either its favored toy or—surprise!—a different item. Many of the surprised dogs continued searching for the toy used to lay the scent trail—an indication that they had a mental representation of what they expected to find, the scientists report today in the Journal of Comparative Psychology. Both family dogs and working dogs scored about the same on the tests, confirming previous studies showing that education doesn’t necessarily improve a dog’s performance. Previous studies have shown that horses have mental images of their owners and other horses—based on the sounds of their voices and whinnies. But scientists know little about how smell and cognition are linked in animals that rely heavily on smell—such as dogs, elephants, and rats. Now, we have a better idea at least for our pooches: They picture what they’re searching for. © 2018 American Association for the Advancement of Science.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 24722 - Posted: 03.06.2018

By Kimberly Hickok If you ever wanted to know what a moth was thinking, this might be as close as you’re going to get. In a new study published today in Cell Reports, researchers placed female hawkmoths (Manduca sexta) in a wind tunnel containing two pieces of filter paper—one covered in a test odor, and one with no odor. Perhaps not surprisingly, the insects were most attracted to odors containing aromatic chemicals, which are present in plants that are common nectar sources. Some odors consistently caused the moths to touch their feet to the paper while curving their abdomen, which is how they lay eggs, indicating that moths associate those odors with egg laying. With six different odors, the moths alternated touching their feet and their mouths to the same odor, suggesting that plants containing one or all of those chemicals, such as jimson weed, are important for both feeding and egg laying. By combining these data with imaging of nerve cells at the base of the moths’ antennae, the researchers identified four clusters of nerves specifically associated with feeding behavior and six specifically associated with egg laying, but none associated with both behaviors. This means moths use specific odors to direct their behavior. The scientists say more research is needed to see whether nerve clusters respond to odor the same way in other species of moths and pollinating insects, which can help identify important odors and the plants that make them. © 2018 American Association for the Advancement of Science.

Keyword: Chemical Senses (Smell & Taste); Sexual Behavior
Link ID: 24706 - Posted: 02.28.2018

By CHRISTOPHER MELE A persistent noise of unknown origin, sometimes compared to a truck idling or distant thunder, has bedeviled a Canadian city for years, damaging people’s health and quality of life, numerous residents say. Those who hear it have compared it to a fleet of diesel engines idling next to your home or the pulsation of a subwoofer at a concert. Others report it rattling their windows and spooking their pets. Known as the Windsor Hum, this sound in Windsor, Ontario, near Detroit, is unpredictable in its duration, timing and intensity, making it all the more maddening for those affected. “You know how you hear of people who have gone out to secluded places to get away from certain sounds or noises and the like?” Sabrina Wiese posted in a private Facebook group dedicated to finding the source of the noise. “I’ve wanted to do that many times in the past year or so because it has gotten so bad,” she wrote. “Imagine having to flee all you know and love just to have a chance to hear nothing humming in your head for hours on end.” Since reports of it surfaced in 2011, the hum has been studied by the Canadian government, the University of Western Ontario and the University of Windsor. Activists have done their own sleuthing. Over six years, Mike Provost of Windsor, who helps run the Facebook page, has amassed more than 4,000 pages of daily observations about the duration, intensity and characteristics of the sound and the weather conditions at the time. © 2018 The New York Times Company

Keyword: Hearing; Brain Injury/Concussion
Link ID: 24681 - Posted: 02.19.2018

Dan Garisto If you’ve ever felt the urge to tap along to music, this research may strike a chord. Recognizing rhythms doesn’t involve just parts of the brain that process sound — it also relies on a brain region involved with movement, researchers report online January 18 in the Journal of Cognitive Neuroscience. When an area of the brain that plans movement was disabled temporarily, people struggled to detect changes in rhythms. The study is the first to connect humans’ ability to detect rhythms to the posterior parietal cortex, a brain region associated with planning body movements as well as higher-level functions such as paying attention and perceiving three dimensions. “When you’re listening to a rhythm, you’re making predictions about how long the time interval is between the beats and where those sounds will fall,” says coauthor Jessica Ross, a neuroscience graduate student at the University of California, Merced. These predictions are part of a system scientists call relative timing, which helps the brain process repetitive sounds, like a musical rhythm. “Music is basically sounds that have a structure in time,” says Sundeep Teki, a neuroscientist at the University of Oxford who was not involved with the study. Studies like this, which investigate where relative timing takes place in the brain, could be crucial to understanding how the brain deciphers music, he says. |© Society for Science & the Public 2000 - 2018.

Keyword: Hearing
Link ID: 24675 - Posted: 02.17.2018

Dana Boebinger Roughly 15 percent of Americans report some sort of hearing difficulty; trouble understanding conversations in noisy environments is one of the most common complaints. Unfortunately, there’s not much doctors or audiologists can do. Hearing aids can amplify things for ears that can’t quite pick up certain sounds, but they don’t distinguish between the voice of a friend at a party and the music in the background. The problem is not only one of technology, but also of brain wiring. Most hearing aid users say that even with their hearing aids, they still have difficulty communicating in noisy environments. As a neuroscientist who studies speech perception, this issue is prominent in much of my own research, as well as that of many others. The reason isn’t that they can’t hear the sounds; it’s that their brains can’t pick out the conversation from the background chatter. Harvard neuroscientists Dan Polley and Jonathon Whitton may have found a solution, by harnessing the brain’s incredible ability to learn and change itself. They have discovered that it may be possible for the brain to relearn how to distinguish between speech and noise. And the key to learning that skill could be a video game. People with hearing aids often report being frustrated with how their hearing aids handle noisy situations; it’s a key reason many people with hearing loss don’t wear hearing aids, even if they own them. People with untreated hearing loss – including those who don’t wear their hearing aids – are at increased risk of social isolation, depression and even dementia. © 2010–2018, The Conversation US, Inc.

Keyword: Hearing; Learning & Memory
Link ID: 24618 - Posted: 02.06.2018

By Jim Daley Researchers at the D’Or Institute for Research and Education in Brazil have created an algorithm that can use functional magnetic resonance imaging (fMRI) data to identify which musical pieces participants are listening to. The study, published last Friday (February 2) in Scientific Reports, involved six participants listening to 40 pieces of music from various genres, including classical, rock, pop, and jazz. “Our approach was capable of identifying musical pieces with improving accuracy across time and spatial coverage,” the researchers write in the paper. “It is worth noting that these results were obtained for a heterogeneous stimulus set . . . including distinct emotional categories of joy and tenderness.” The researchers first played different musical pieces for the participants and used fMRI to measure the neural signatures of each song. With that data, they taught a computer to identify brain activity that corresponded with the musical dimensions of each piece, including tonality, rhythm, and timbre, as well as a set of lower-level acoustic features. Then, the researchers played the pieces for the participants again while the computer tried to identify the music each person was listening to, based on fMRI responses. The computer was successful in decoding the fMRI information and identifying the musical pieces around 77 percent of the time when it had two options to choose from. When the researchers presented 10 possibilities, the computer was correct 74 percent of the time. © 1986-2018 The Scientist

Keyword: Hearing; Brain imaging
Link ID: 24617 - Posted: 02.06.2018

By VERONIQUE GREENWOOD Of the five tastes — sweet, salty, sour, bitter and umami — sour is one of the most mysterious. Bite into a piece of lemon and — bing! — your brain gets a message that something sour has arrived. But unlike sweet and bitter, for example, for which biologists have identified proteins on the tongue’s taste cells that detect the molecules involved, the sourness of acids like lemon juice and vinegar has remained enigmatic, with the exact details of how we pick up on it little understood. Now, however, in a paper published last month in Science, researchers report that they have found a protein in mouse taste cells that is likely a key player in the detection of sour flavors. There’s just one strange thing, though: Biologists have known about this protein for years. It was previously identified in the inner ear, or vestibular system, of mice, humans and many other creatures, where it is required for developing a sense of balance. The results suggest a fascinating truth about evolution: The first place something is discovered may not be the last place it turns up. If it has proved advantageous over the eons, a protein whose purpose we thought we understood may have a rich private life of its own elsewhere in the body, just waiting to be found. Similar discoveries have cropped up more and more in the last decade as researchers look more closely at which genes cells are using. This approach has led to the revelations that smell receptors are alive and well in the kidneys, bitter taste receptors dot the sinuses and testes, and sweet taste receptors are found in the bladder. © 2018 The New York Times Company

Keyword: Chemical Senses (Smell & Taste); Hearing
Link ID: 24616 - Posted: 02.05.2018

By Matt Warren The cheetah is built for running, with long limbs and powerful muscles that propel it along as it chases down its prey. But a new study has found that the world’s fastest land mammal has another, less obvious adaptation hidden away in its inner ear. Scientists suspected that the cheetah might also rely on a specialized vestibular system, the part of the inner ear that detects head movements and helps animals maintain their gaze and posture. Using computerized tomography scans, they created detailed 3D images of the inner ear from the skulls of cheetahs and other cat species, from leopards to domestic cats. They found that the vestibular system took up a much greater part of the inner ear in cheetahs than in any other cat. The cheetahs also had elongated semicircular canals, parts of the system involved in head movement and eye direction. These features help the animal catch dinner by letting it keep its head still and its eyes on the prize, even when the rest of its body is rapidly moving, the researchers write in Scientific Reports. The extinct giant cheetah did not have the same features, suggesting that the distinct vestibular system evolved fairly recently, they say. © 2018 American Association for the Advancement of Science

Keyword: Hearing
Link ID: 24607 - Posted: 02.03.2018

By Diana Kwon Search for “pheromones products” on the internet, and dozens of sprays and perfume additives will appear—many claiming to be able to increase your attractiveness to the opposite sex. Some companies, such as the Athena Institute, which, according to its founder, Winnifred Cutler, published its 108th consecutive ad in The Atlantic this month, assert that scientific studies back up their claims. While there have been several experiments examining the effects of compounds extracted from people’s armpits, much of the data on sex-related behaviors, The Scientist has found, go back more than a decade and were met then—and still now—with skepticism from pheromone researchers. “I am not compelled by any studies that are out there that say there is an active steroid component from the underarm that causes [sexual attraction],” says George Preti, an organic chemist at the Monell Chemical Senses Center in Philadelphia who conducted some of the early human pheromone trials. Within the scientific community, pheromones are broadly defined as chemical signals released by an animal that induce specific effects on other members of the same species. Although these substances are typically associated with sexual attraction, researchers have found they can have a broader range of influence, such as prompting aggression or modifying parental behaviors. © 1986-2018 The Scientist

Keyword: Chemical Senses (Smell & Taste); Sexual Behavior
Link ID: 24565 - Posted: 01.25.2018

By Kate Baggaley The pain came without warning. It was February of last year, and the man was eating dinner. He’d just reached for a glass of wine. “It really burned my mouth when I started to drink,” says Greg (the healthcare worker in Toronto asked for his name to be changed). The odd and disquieting sensation had no apparent cause—no burns or cuts or other injuries. Yet the burning and tingling Greg felt on his tongue and the roof of his mouth persisted. “It was very intense during the middle of the day and then subsided at nighttime,” he says. Perhaps, he was told when finally visiting the family doctor months later, the pain was related to a yeast infection on the tongue. But the prescribed anti-fungal medication made no difference. Next Greg saw a dentist, who found no abnormalities in his mouth and recommended he get a blood test to rule out an autoimmune disorder. Eventually, though, one of Greg’s doctors referred him to Miriam Grushka, an oral medicine specialist in Toronto. Grushka has spent decades studying and treating Greg's condition, which is called burning mouth syndrome. “People say they feel like they burnt their tongue on a cup of coffee, but the burning never went away,” says Grushka. “In the vast majority of cases it’s benign, but it’s very uncomfortable.” Each week, she sees around 15 patients who have burning mouth syndrome or similar conditions. These hallucinations, or phantoms, are characterized by a taste or feeling in the mouth that will not go away. Oral phantoms are often treatable, and are rooted not in the mouth but the brain. But much else about these phantom feelings is still a mystery. Grushka and other researchers are still unraveling why they happen and how to banish them. © 2018 Popular Science.

Keyword: Pain & Touch; Chemical Senses (Smell & Taste)
Link ID: 24548 - Posted: 01.22.2018

By Kimberly Hickok A rooster’s crow is so loud, it can deafen you if you stand too close. So how do the birds keep their hearing? To find out, researchers attached recorders to the heads of three roosters, just below the base of their skulls. Crows lasted 1 to 2 seconds and averaged more than 130 decibels. That’s about the same intensity as standing 15 meters away from a jet taking off. One rooster’s crows reached more than 143 decibels, which is more like standing in the middle of an active aircraft carrier. The researchers then used a micro–computerized tomography scan to create a 3D x-ray image of the birds’ skulls. When a rooster’s beak is fully open, as it is when crowing, a quarter of the ear canal completely closes and soft tissue covers 50% of the eardrum, the team reports in a paper in press at Zoology. This means roosters aren’t capable of hearing their own crows at full strength. The intensity of a rooster’s crow diminishes greatly with distance, so it probably doesn’t cause significant hearing loss in nearby hens. But if it did, she’d likely be OK. Unlike mammals, birds can quickly regenerate hair cells in the inner ear if they become damaged. © 2018 American Association for the Advancement of Science.

Keyword: Hearing
Link ID: 24542 - Posted: 01.20.2018

Bruce Bower Smell has a reputation as a second-rate human sense. But that assumption stinks once hunter-gatherers enter the picture. Semaq Beri hunter-gatherers, who live in tropical forests on the eastern side of the Malay Peninsula in Southeast Asia, name various odors as easily as they name colors, say psycholinguist Asifa Majid and linguist Nicole Kruspe. Yet Semelai rice farmers, who live in forest outposts near the Semaq Beri and speak a closely related language, find odors much more difficult to name than colors, the researchers report online January 18 in Current Biology. By including members of a farming community that inhabit a common forest environment and speak a similar language, the new study indicates for the first time that the cultural practices of hunter-gatherers help enhance their odor-naming ability — and possibly their smell-detection skills — relative to settled peoples. Neuroscientist and odor researcher John McGann of Rutgers University in Piscataway, N.J., calls these results “unexpected and deeply interesting.” Genetics apparently interact with personal experiences of different smells and one’s cultural background to produce odor-naming abilities, McGann says. Previous research has found that like Semelai farmers, Westerners describe colors far more easily than smells. People in Western societies often talk about odors by resorting to analogies, such as “It smells like banana.” Semaq Beri hunter-gatherers usually used specific terms for a range of odors as well as colors, say Majid of Radboud University in Nijmegen, the Netherlands, and Kruspe of Lund University in Sweden. These forest dwellers are attuned to odors by virtue of their lifestyle and culture, the investigators propose. |© Society for Science & the Public 2000 - 2017.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 24541 - Posted: 01.19.2018

By Katarina Zimmer Scientists can trace the evolutionary histories of bats and humans back to a common ancestor that lived some tens of millions of years ago. And on the surface, those years of evolutionary divergence have separated us from the winged mammals in every way possible. But look on a sociobehavioral level, as some bat researchers are doing, and the two animal groups share much more than meets the eye. Like humans, bats form huge congregations of up to millions of individuals at a time. On a smaller scale, they form intimate social bonds with one another. And recently, scientists have suggested that bats are capable of vocal learning—the ability to modify vocalizations after hearing sounds. Researchers long considered this skill to be practiced only by humans, songbirds, and cetaceans, but have more recently identified examples of vocal learning in seals, sea lions, elephants—and now, bats. In humans, vocal learning can take the form of adopting styles of speech—for example, if a Brit were to pick up an Australian accent after moving down under. Yossi Yovel, a physicist turned bat biologist at Tel Aviv University who has long been fascinated by animal behavior, recently demonstrated that bat pups can acquire “dialects” in a similar way. © 1986-2018 The Scientist

Keyword: Language; Animal Communication
Link ID: 24529 - Posted: 01.16.2018

By Kelly Crowe, "Scientists identify a sixth taste sense." It's a claim that has made headlines several times over the last few years — first for fat, then for starch and even for water. Now the new candidate for the sixth taste is calcium, after scientists identified the first calcium taste receptors in fruit flies. Researchers at the University of California studied fruit fly behaviour and discovered the flies could taste toxic levels of calcium and didn't like it. Then they used genetics to show that the calcium taste sense is hardwired into the fruit fly brain. University of California professor Craig Montell believes humans might share the fruit fly's taste sensor for calcium. (UC Santa Barbara) And because fruit flies and humans share the other main taste senses — sweet, sour, bitter, salty and savoury (called "umami") — the study's lead author, Craig Montell, thinks there's a good chance that humans also have specific calcium taste receptors. "I would say there is very good reason that, given that all the other tastes have been well conserved between flies and humans, that there probably is," said Montell. But the science of taste is surprisingly complicated. Even the idea that there might be additional taste receptors is controversial. As far back as Aristotle's time, scientists have been puzzling over the question. ©2018 CBC/Radio-Canada.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 24526 - Posted: 01.15.2018

Alison Abbott The brain’s navigation system — which keeps track of where we are in space — also monitors the movements of others, experiments in bats and rats suggest. In a study published in Science1 on 11 January, neuroscientists in Israel pinpoint individual brain cells that seem specialized to track other animals or objects. These cells occur in the same region of the brain — the hippocampus — as cells that are known to map a bat’s own location. In a second paper2, scientists in Japan report finding similar brain activity when rats watched other rats moving. The unexpected findings deepen insight into the mammalian brain’s complex navigation system. Bats and rats are social animals that, like people, need to know the locations of other members of their group so that they can interact, learn from each other and move around together. Researchers have already discovered several different types of cell whose signals combine to tell an animal where it is: ‘place’ cells, for example, fire when animals are in a particular location, whereas other types correspond to speed or head direction, or even act as a kind of compass. The latest reports mark the first discovery of cells that are attuned to other animals, rather than the self. “Obviously, the whereabouts of others must be encoded somewhere in the brain, but it is intriguing to see that it seems be in the same area that tracks self,” says Edvard Moser, a neuroscientist at the Kavli Institute for Systems Neuroscience in Trondheim, Norway, who shared the 2014 Nobel Prize in Physiology or Medicine for revealing elements of the navigation system. © 2018 Macmillan Publishers Limited,

Keyword: Hearing
Link ID: 24523 - Posted: 01.12.2018

By Emily Anthes Men with autism respond differently to human odors — and the social signals that they contain — than do their neurotypical peers, according to a new study. The results suggest that men with autism misread social signals present in human odors — causing them to misinterpret others’ emotions. Human sweat contains chemicals believed to convey social and emotional information. For instance, when women smell sweat collected from men watching scary movies, they are more likely to describe faces with ambiguous expressions as fearful. Advertisement In the new study, researchers exposed men to sweat collected from people who were skydiving. Unlike controls, men with autism do not show increased skin conductance, a measure of physiological arousal, to this ‘fear sweat.’ They are also more likely than controls to trust a mannequin that emits this scent. “I think this could be a meaningful aspect of impaired social interaction,” says lead investigator Noam Sobel, professor of neurobiology at the Weizmann Institute of Science in Rehovot, Israel. “Humans constantly engage in social chemo-signaling; we do this all the time, and it shapes our interactions,” he says. “And somehow these mechanisms work differently in autism.” Several studies have examined olfaction in people with autism. Researchers have found, for example, that children with autism inhale odors differently than their typical peers do, and some children with the condition may be particularly sensitive to smells. © 2017 Scientific American

Keyword: Autism; Chemical Senses (Smell & Taste)
Link ID: 24459 - Posted: 12.26.2017

Hannah Devlin Science correspondent Deafness has been prevented in mice using gene editing for the first time, in an advance that could transform future treatment of genetic hearing loss. The study found that a single injection of a gene editing cocktail prevented progressive deafness in baby animals that were destined to lose their hearing. “We hope that the work will one day inform the development of a cure for certain forms of genetic deafness in people,” said Prof David Liu, who led the work at Harvard University and MIT. Nearly half of all cases of deafness have a genetic root, but current treatment options are limited. However, the advent of new high-precision gene editing tools such as Crispr has raised the prospect of a new class of therapies that target the underlying problem. The study, published in the journal Nature, focused on a mutation in a gene called Tmc1, a single wrong letter in the genetic code, that causes the loss of the inner ear’s hair cells over time. The delicate hairs, which sit in a spiral-shaped organ called the cochlea, vibrate in response to sound waves. Nerve cells pick up the physical motion and transmit it to the brain, where it is perceived as sound. If a child inherits one copy of the mutated Tmc1 gene they will suffer progressive hearing loss, normally starting in the first decade of life and resulting in profound deafness within 10 to 15 years. However, since most people affected by the mutation will also have a healthy version of the gene, inherited from their other parent, the scientists wanted to explore whether deleting the faulty version worked as a treatment. © 2017 Guardian News and Media Limited

Keyword: Hearing; Genes & Behavior
Link ID: 24449 - Posted: 12.21.2017

by Ben Guarino Each year between February and June, the fish gather to spawn in Mexico's Colorado River Delta. The fish, a type of croaker called the Gulf corvina, meet in water as cloudy as chocolate milk. It's a reunion for the entire species, all members of which reproduce within a dozen-mile stretch of the delta. When the time is right, a few days before the new or full moons, the male fish begin to sing. To humans, the sound is machine guns going off just below the waterline. To female fish, the rapid burr-burr-burr is a Bing Crosby croon. Make that Bing cranked up to 11. Marine biologists who recorded the sound describe the animals as the “loudest fish ever documented,” said Timothy J. Rowell, at the Scripps Institution of Oceanography in California. Rowell and Brad E. Erisman, a University of Texas at Austin fisheries scientist, spent four days in 2014 snooping on the fish with sonar and underwater microphones. The land surrounding the delta is desolate, Rowell said. Fresh water that once fed wild greenery has been diverted to faucets and hoses. But the delta is alive with the sound of fish. “When you arrive at the channels of the delta, you can hear it in the air even while the engine is running on the boat,” Rowell said. © 1996-2017 The Washington Post

Keyword: Hearing; Animal Communication
Link ID: 24443 - Posted: 12.20.2017