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

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Gina Mantica Have you ever seen a picture of a mother dog caring for an unusual baby, like a kitten? This sort of animal adoption story is an example of a phenomenon known as alloparenting: care provided to offspring that are not genetically related. We humans may toss around the phrase “It takes a village to raise a child,” but there are cases in the animal world where this is more literally true. Naked mole-rats, wrinkly mammals of the East African desert, offer an example of the whole “village” cooperating to raise offspring. Each individual naked mole-rat has a specific job. Like in a honeybee hive, a naked mole-rat colony has one queen, whose job it is to reproduce. There are just a few sexually reproductive males, who mate with the queen. All the others, both male and female, are either soldiers that protect the colony or workers that forage for food, dig tunnels and care for the queen’s offspring, known as pups. Until now, no one had a physiological explanation for why naked mole-rat workers care for pups that aren’t their own. Normally when a mom gives birth, estrogen levels are high and progesterone levels drop, resulting in maternal behaviors such as feeding or grooming. In many unusual adoption stories, like that of the mother dog caring for a kitten, the adoptive mom will have recently given birth to her own offspring – meaning her hormone levels have left her primed and ready to care for offspring, even those that aren’t her own. © 2010–2018, The Conversation US, Inc.

Keyword: Sexual Behavior; Chemical Senses (Smell & Taste)
Link ID: 25577 - Posted: 10.16.2018

By Jane E. Brody Jane R. Madell, a pediatric audiology consultant and speech-language pathologist in Brooklyn, N.Y., wants every parent with a child who is born hearing-impaired to know that it is now possible for nearly all children with severe hearing loss to learn to listen and speak as if their hearing were completely normal. “Children identified with hearing loss at birth and fitted with technology in the first weeks of life blend in so well with everyone else that people don’t realize there are so many deaf children,” she told me. With the appropriate hearing device and auditory training for children and their caregivers during the preschool years, even those born deaf “will have the ability to learn with their peers when they start school,” Dr. Madell said. “Eighty-five percent of such children are successfully mainstreamed. Parents need to know that listening and spoken language is a possibility for their children.” Determined to get this message out to all who learn their children lack normal hearing, Dr. Madell and Irene Taylor Brodsky produced a documentary, “The Listening Project,” to demonstrate the enormous help available through modern hearing assists and auditory training. Among the “stars” in the film, all of whom grew up deaf or severely hearing-impaired, are Dr. Elizabeth Bonagura, an obstetrician-gynecologist and surgeon; Jake Spinowitz, a musician; Joanna Lippert, a medical social worker, and Amy Pollick, a psychologist. All started out with hearing aids that helped them learn to speak and understand spoken language. But now all have cochlear implants that, as Ms. Lippert put it, “really revolutionized my world” when, at age 11, she became the first preteen to get a cochlear implant at New York University Medical Center. © 2018 The New York Times Company

Keyword: Hearing
Link ID: 25541 - Posted: 10.08.2018

Susan Milius It’s a lovely notion, but tricky to prove. Still, lemurs sniffing around wild fruits in Madagascar are bolstering the idea that animal noses contributed to the evolution of aromas of fruity ripeness. The idea sounds simple, says evolutionary ecologist Omer Nevo of the University of Ulm in Germany. Plants can use mouth-watering scents to lure animals to eat fruits, and thus spread around the seeds. But are those odors really advertising, or are they just the way fruits happen to smell as they ripen? For some wild figs and a range of other fruits in eastern Madagascar, a strong scent of ripeness does seem to have evolved in aid of allure, Nevo and his colleagues argue October 3 in Science Advances. A lot of fruit collecting and odor chemistry suggest that fruits dispersed by lemurs, with their sensitive noses, change more in scent than fruits that rely more on birds with acute color vision. Earlier studies had sniffed around several species, such as figs. But for a broader look, Nevo and his colleagues analyzed scents from 25 other kinds of fruits as well as five kinds of figs. All grew wild in a “really magnificent” mountainous rainforest preserved as a park in eastern Madagascar, Nevo says. The researchers classified 19 of the plants as depending largely on red-bellied and other local lemurs to spread seeds. Most of these lemurs are red-green color-blind, not great for spotting the ripe fruits among foliage. But the researchers following some lemurs foraging in daylight noticed that sniffing at fruits was a big deal for the primates. |© Society for Science & the Public 2000 - 2018

Keyword: Chemical Senses (Smell & Taste); Evolution
Link ID: 25528 - Posted: 10.04.2018

Craig Richard Have you ever stumbled upon an hourlong online video of someone folding napkins? Or maybe crinkling paper, sorting a thimble collection or pretending to give the viewer an ear exam? They’re called ASMR videos and millions of people love them and consider watching them a fantastic way to relax. Other viewers count them among the strangest things on the internet. So are they relaxing or strange? I think they are both, which is why I have been fascinated with trying to understand ASMR for the past five years. In researching my new book “Brain Tingles,” I explored the many mysteries about ASMR as well as best practices for incorporating ASMR into various aspects of life, like parenting, spas and health studios. ASMR is short for Autonomous Sensory Meridian Response. Enthusiast Jennifer Allen coined the term in 2010. You may also hear this phenomenon called “head orgasms” or “brain tingles.” It’s distinct from the “aesthetic chills” or frisson some people experience when listening to music, for instance. People watch ASMR videos in hopes of eliciting the response, usually experienced as a deeply relaxing sensation with pleasurable tingles in the head. It can feel like the best massage in the world – but without anyone touching you. Imagine watching an online video while your brain turns into a puddle of bliss. The actions and sounds in ASMR videos mostly recreate moments in real life that people have discovered spark the feeling. These stimuli are called ASMR triggers. They usually involve receiving personal attention from a caring person. Associated sounds are typically gentle and non-threatening. © 2010–2018, The Conversation US, Inc.

Keyword: Hearing; Emotions
Link ID: 25498 - Posted: 09.27.2018

By William J. Broad During the Cold War, Washington feared that Moscow was seeking to turn microwave radiation into covert weapons of mind control. More recently, the American military itself sought to develop microwave arms that could invisibly beam painfully loud booms and even spoken words into people’s heads. The aims were to disable attackers and wage psychological warfare. Now, doctors and scientists say such unconventional weapons may have caused the baffling symptoms and ailments that, starting in late 2016, hit more than three dozen American diplomats and family members in Cuba and China. The Cuban incidents resulted in a diplomatic rupture between Havana and Washington. The medical team that examined 21 affected diplomats from Cuba made no mention of microwaves in its detailed report published in JAMA in March. But Douglas H. Smith, the study’s lead author and director of the Center for Brain Injury and Repair at the University of Pennsylvania, said in a recent interview that microwaves were now considered a main suspect and that the team was increasingly sure the diplomats had suffered brain injury. “Everybody was relatively skeptical at first,” he said, “and everyone now agrees there’s something there.” Dr. Smith remarked that the diplomats and doctors jokingly refer to the trauma as the immaculate concussion. Strikes with microwaves, some experts now argue, more plausibly explain reports of painful sounds, ills and traumas than do other possible culprits — sonic attacks, viral infections and contagious anxiety. In particular, a growing number of analysts cite an eerie phenomenon known as the Frey effect, named after Allan H. Frey, an American scientist. Long ago, he found that microwaves can trick the brain into perceiving what seem to be ordinary sounds. The false sensations, the experts say, may account for a defining symptom of the diplomatic incidents — the perception of loud noises, including ringing, buzzing and grinding. Initially, experts cited those symptoms as evidence of stealthy attacks with sonic weapons. © 2018 The New York Times Company

Keyword: Brain Injury/Concussion; Hearing
Link ID: 25410 - Posted: 09.01.2018

By James Gorman It’s not easy to help ducks. Ask Kate McGrew, a masters student in wildlife ecology at the University of Delaware. Over two seasons, 2016 and 2017, she spent months raising and working with more than two dozen hatchlings from three different species, all to determine what they hear underwater. This was no frivolous inquiry. Sea ducks, like the ones she trained, dive to catch their prey in oceans around the world and are often caught unintentionally in fish nets and killed. Christopher Williams, a professor at the university who is Ms. McGrew’s adviser, said one estimate puts the number of ducks killed at sea at 400,000 a year, although he said the numbers are hard to pin down. A similar problem plagues marine mammals, like whales, and acoustic devices have been developed to send out pings that warn them away from danger. A similar tactic might work with diving ducks, but first, as Dr. Williams said, it would make sense to answer a question that science hasn’t even asked about diving ducks: “What do they hear?” “There actually is little to no research done on duck hearing in general,” Ms. McGrew said, “and on the underwater aspect of it, there’s even less.” That’s the recipe for a perfect, although demanding research project. Her goal was to use three common species of sea ducks to study a good range of underwater hearing ability. But while you can lead a duck to water and it will paddle around naturally, teaching it to take a hearing test is another matter entirely. © 2018 The New York Times Company

Keyword: Hearing
Link ID: 25389 - Posted: 08.28.2018

Laurel Hamers Dealing with poop is an unavoidable hazard of raising children, regardless of species. But for naked mole rats, that wisdom is especially salient. During pregnancy, the scat of a naked mole rat queen — the only female in the colony that reproduces, giving birth to a few dozen pups each year — contains high levels of the sex hormone estradiol. When subordinate female naked mole rats eat that poop, the estradiol they pick up cues them to snap into parenting mode and care for the queen’s offspring, researchers report the week of August 27 in the Proceedings of the National Academy of Sciences. In colonies of naked mole rats (Heterocephalus glaber), lower-ranking females don’t have developed ovaries and don’t reproduce. They also don’t experience the pregnancy-induced hormonal shifts that usually cue parenting behaviors, yet they still care for the queen’s babies. Researchers gave poop pellets from nonpregnant queens to subordinates for nine days. One group got pellets with added estradiol, to mimic pregnancy poop. Levels of estradiol increased in the dung of subordinate females that ate the hormone-packed pellets, suggesting that scat snacks could induce measurable hormonal changes. And those mole rats were more responsive to the cries of pups than those that didn’t get the hormone boost, the team found. |© Society for Science & the Public 2000 - 2018.

Keyword: Sexual Behavior; Chemical Senses (Smell & Taste)
Link ID: 25383 - Posted: 08.28.2018

Abby Olena Scientists have been looking for years for the proteins that convert the mechanical movement of inner ears’ hair cells into an electrical signal that the brain interprets as sound. In a study published today (August 22) in Neuron, researchers have confirmed that transmembrane channel-like protein 1 (TMC1) contributes to the pore of the so-called mechanotransduction channel in the cells’ membrane. “The identification of the channel has been missing for a long time,” says Anthony Peng, a neuroscientist at the University of Colorado Denver who did not participate in the study. This work “settles the debate as to whether or not [TMC1] is a pore-lining component of the mechanotransduction channel.” When a sound wave enters the cochlea, it wiggles protrusions called stereocilia on both outer hair cells, which amplify the signals, and inner hair cells, which convert the mechanical signals to electric ones and send them to the brain. It’s been tricky to figure out what protein the inner hair cells use for this conversion, because their delicate environment is difficult to recreate in vitro in order to test candidate channel proteins. In 2000, researchers reported on a promising candidate in flies, but it turned out not to be conserved in mammals. In a study published in 2011, Jeffrey Holt of Harvard Medical School and Boston Children’s Hospital and colleagues showed that genes for TMC proteins were necessary for mechanotransduction in mice. This evidence—combined with earlier work from another group showing that mutations in these genes could cause deafness in humans—pointed to the idea that TMC1 formed the ion channel in inner ear hair cells. © 1986 - 2018 The Scientist

Keyword: Hearing
Link ID: 25372 - Posted: 08.24.2018

Imagine the foul smell of an ash tray or burning hair. Now imagine if these kinds of smells were present in your life, but without a source. A new study finds that 1 in 15 Americans (or 6.5 percent) over the age of 40 experiences phantom odors. The study, published in JAMA Otolaryngology-Head and Neck Surgery (link is external), is the first in the U.S. to use nationally representative data to examine the prevalence of and risk factors for phantom odor perception. The study could inform future research aiming to unlock the mysteries of phantom odors. The study was led by Kathleen Bainbridge, Ph.D., of the Epidemiology and Biostatistics Program at the National Institute on Deafness and Other Communication Disorders (NIDCD), part of the National Institutes of Health. Bainbridge and her team used data from 7,417 participants over 40 years of age from the 2011-2014 National Health and Nutrition Examination Survey (NHANES) (link is external). The NHANES data were collected by the National Center for Health Statistics, which is part of the Centers for Disease Control and Prevention; data collection was partly funded by the NIDCD. Donald Leopold, M.D., one of the study’s authors and clinical professor in the Department of Surgery at University of Vermont Medical Center, Burlington, adds that patients who perceive strong phantom odors often have a miserable quality of life, and sometimes cannot maintain a healthy weight. The ability to identify odors tends to decrease with age. Phantom odor perception, on the other hand, seems to improve with age. One previous study, using data from a community in Sweden, showed that 4.9 percent of people over the age of 60 experience phantom odors, with a higher prevalence in women than men. The present study found a similar prevalence in the over-60 age group, but in examining a broader age range, found an even higher prevalence in ages 40-60. The study also found that about twice as many women as men reported phantom odors, and that the female predominance was particularly striking for those under age 60.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 25347 - Posted: 08.18.2018

Ian Sample Science editor Claims that US diplomats suffered mysterious brain injuries after being targeted with a secret weapon in Cuba have been challenged by neurologists and other brain specialists. A medical report commissioned by the US government, published in March, found that staff at the US embassy in Havana suffered concussion-like brain damage after hearing strange noises in homes and hotels, but doctors from the US, the UK and Germany have contested the conclusions. In four separate letters to the Journal of the American Medical Association, which published the original medical study, groups of doctors specialising in neurology, neuropsychiatry and neuropsychology described what they believed were major flaws in the study. Among the criticisms, published on Tuesday, are that the University of Pennsylvania team which assessed the diplomats misinterpreted test results, overlooked common disorders that might have made the workers feel sick, or dismissed psychological explanations for their symptoms. Doctors at the University of Pennsylvania defended their report in a formal response in the journal, but the specialists told the Guardian they stood by their criticisms. The US withdrew more than half of its Havana diplomats last year and expelled 15 Cubans after 24 embassy staff and family reported a bizarre list of symptoms, ranging from headaches, dizziness and difficulties in sleeping, to problems with concentration, balance, vision and hearing. Many said their symptoms developed after they heard strange noises, described as cicada-like chirps, grinding, or the buffeting caused by an open window in the car. © 2018 Guardian News and Media Limited

Keyword: Brain Injury/Concussion; Hearing
Link ID: 25334 - Posted: 08.15.2018

By Victoria Davis An elephant’s trunk is the Swiss army knife of appendages: It’s used to breathe, communicate, and even lift objects. Now, a new study finds another use—sniffing out food across long distances. Researchers have long known that elephants and other plant-eating mammals seek their supper with their eyes. But scientists at the Adventures with Elephants facility near Bela Bela, South Africa, wanted to know whether they could do the same thing with their trunks. So they collected 11 plants eaten by wild African elephants (Loxodonta africana), six of which the animals loved and five of which were not nearly as appealing. In one experiment, the elephants had to use their sense of smell to choose between two small samples of plants concealed in black plastic bins. The elephants tended to pick “preferred” plants when the other option was a nonpreferred species, but they had a harder time choosing if both plants were either “preferred” or “nonpreferred.” In a second experiment, the elephants were put into a Y-shaped maze, with a different plant at each end of two 7-meter-long arms. In this formulation, they always chose the preferred plant over the less desired species, the researchers report in Animal Behavior. They were even able to differentiate between plants that fell closely together on the love-hate scale. © 2018 American Association for the Advancement of Science.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 25300 - Posted: 08.07.2018

By Matthew Hutson For millions who can’t hear, lip reading offers a window into conversations that would be lost without it. But the practice is hard—and the results are often inaccurate (as you can see in these Bad Lip Reading videos). Now, researchers are reporting a new artificial intelligence (AI) program that outperformed professional lip readers and the best AI to date, with just half the error rate of the previous best algorithm. If perfected and integrated into smart devices, the approach could put lip reading in the palm of everyone’s hands. “It’s a fantastic piece of work,” says Helen Bear, a computer scientist at Queen Mary University of London who was not involved with the project. Writing computer code that can read lips is maddeningly difficult. So in the new study scientists turned to a form of AI called machine learning, in which computers learn from data. They fed their system thousands of hours of videos along with transcripts, and had the computer solve the task for itself. The researchers started with 140,000 hours of YouTube videos of people talking in diverse situations. Then, they designed a program that created clips a few seconds long with the mouth movement for each phoneme, or word sound, annotated. The program filtered out non-English speech, nonspeaking faces, low-quality video, and video that wasn’t shot straight ahead. Then, they cropped the videos around the mouth. That yielded nearly 4000 hours of footage, including more than 127,000 English words. © 2018 American Association for the Advancement of Science

Keyword: Hearing; Robotics
Link ID: 25280 - Posted: 08.01.2018

by Juliet Corwin On the deafness scale of mild, moderate, severe or profound, I am profoundly deaf. With the help of cochlear implants, I am able to “hear” and speak. The devices are complicated to explain, but basically, external sound processors, worn behind the ears, send a digital signal to the implants, which convert the signal to electric impulses that stimulate the hearing nerve and provide sound signals to the brain. The implants allow me to attend my middle school classes with few accommodations, but I’m still quite different from people who hear naturally. When my implant processors are turned off, I don’t hear anything. I regard myself as a deaf person, and I am proud to be among those who live with deafness, yet I often feel rejected by some of these same people. My use of cochlear implants and lack of reliance on American Sign Language (I use it but am not fluent — I primarily speak) are treated like a betrayal by many in the Deaf — capital-D — community. In the view of many who embrace Deaf culture, a movement that began in the 1970s, those who are integrated into the hearing world through technology, such as hearing aids or cochlear implants, myself included, are regarded as “not Deaf enough” to be a part of the community. People deaf from birth or through illness or injury already face discrimination. I wish we didn’t practice exclusion among ourselves. But it happens, and it’s destructive. © 1996-2018 The Washington Post

Keyword: Hearing
Link ID: 25247 - Posted: 07.25.2018

Alison Abbott On a sun-parched patch of land in Rehovot, Israel, two neuroscientists peer into the darkness of a 200-metre-long tunnel of their own design. The fabric panels of the snaking structure shimmer in the heat, while, inside, a study subject is navigating its dim length. Finally, out of the blackness bursts a bat, which executes a mid-air backflip to land upside down, hanging at the tunnel’s entrance. The vast majority of experiments probing navigation in the brain have been done in the confines of labs, using earthbound rats and mice. Ulanovsky broke with the convention. He constructed the flight tunnel on a disused plot on the grounds of the Weizmann Institute of Science — the first of several planned arenas — because he wanted to find out how a mammalian brain navigates a more natural environment. In particular, he wanted to know how brains deal with a third dimension. The tunnel, which Ulanovsky built in 2016, has already proved its scientific value. So have the bats. They have helped Ulanovsky to discover new aspects of the complex encoding of navigation — a fundamental brain function essential for survival. He has found a new cell type responsible for the bats’ 3D compass, and other cells that keep track of where other bats are in the environment. It is a hot area of study — navigation researchers won the 2014 Nobel Prize in Physiology or Medicine and the field is an increasingly prominent fixture at every big neuroscience conference. “Nachum’s boldness is impressive,” says Edvard Moser of the Kavli Institute for Systems Neuroscience in Trondheim, Norway, one of the 2014 Nobel laureates. “And it’s paid off — his approach is allowing important new questions to be addressed.” . © 2018 Springer Nature Limited.

Keyword: Hearing
Link ID: 25198 - Posted: 07.12.2018

By Elizabeth Pennisi Bats and their prey are in a constant arms race. Whereas the winged mammals home in on insects with frighteningly accurate sonar, some of their prey—such as the tiger moth—fight back with sonar clicks and even jamming signals. Now, in a series of bat-moth skirmishes (above), scientists have shown how other moths create an “acoustic illusion,” with long wing-tails that fool bats into striking the wrong place. The finding helps explain why some moths have such showy tails, and it may also provide inspiration for drones of the future. Moth tails vary from species to species: Some have big lobes at the bottom of the hindwing instead of a distinctive tail; others have just a short protrusion. Still others have long tails that are thin strands with twisted cuplike ends. In 2015, sensory ecologist Jesse Barber of Boise State University in Idaho and colleagues discovered that some silk moths use their tails to confuse bat predators. Now, graduate student Juliette Rubin has shown just what makes the tails such effective deterrents. Working with three species of silk moths—luna, African moon, and polyphemus—Rubin shortened or cut off some of their hindwings and glued longer or differently shaped tails to others. She then tied the moths to a string hanging from the top of a large cage and released a big brown bat (Eptesicus fuscus) inside. She used high-speed cameras and microphones to record the ensuing fight. © 2018 American Association for the Advancement of Science.

Keyword: Hearing; Evolution
Link ID: 25173 - Posted: 07.05.2018

A small-molecule drug is one of the first to preserve hearing in a mouse model of an inherited form of progressive human deafness, report investigators at the University of Iowa, Iowa City, and the National Institutes of Health’s National Institute on Deafness and Other Communication Disorders (NIDCD). The study, which appears online in Cell (link is external), sheds light on the molecular mechanism that underlies a form of deafness (DFNA27), and suggests a new treatment strategy. “We were able to partially restore hearing, especially at lower frequencies, and save some sensory hair cells,” said Thomas B. Friedman, Ph.D., chief of the Laboratory of Human Molecular Genetics at the NIDCD, and a coauthor of the study. “If additional studies show that small-molecule-based drugs are effective in treating DFNA27 deafness in people, it’s possible that using similar approaches might work for other inherited forms of progressive hearing loss.” The seed for the advance was planted a decade ago, when NIDCD researchers led by Friedman and Robert J. Morell, Ph.D., another coauthor of the current study, analyzed the genomes of members of an extended family, dubbed LMG2. Deafness is genetically dominant in the LMG2 family, meaning that a child needs to inherit only one copy of the defective gene from a parent to have progressive hearing loss. The investigators localized the deafness-causing mutation to a region on chromosome four called DFNA27, which includes a dozen or so genes. The precise location of the mutation eluded the NIDCD team, however.

Keyword: Hearing; Regeneration
Link ID: 25160 - Posted: 06.29.2018

By James Gorman In the world of noses, the elephant’s trunk clearly stands out for its size, flexibility, strength and slightly creepy gripping ability. Go ahead, try to pluck a leaf with your nostrils and see how you fare.So perhaps it should come as no surprise that the elephant’s sense of smell is also outstanding. Past studies have shown that elephants have more scent receptors than any other mammal. And in other experiments, researchers following up reports that elephants in Angola were avoiding minefields found that they could detect TNT. Another report concluded that elephants could use scent clues to tell the difference between two Kenyan tribes, the Maasai, who traditionally speared them, and the Kamba, who did not. The elephants apparently used these clues to help them avoid the Maasai. The latest bit of research adds to the evidence by showing how they use their great sense of smell in choosing food. Elephants often must find vegetation and water at a distance, and they also distinguish between fairly similar plants once they reach a clump of likely vegetation. It seemed that they probably used their sense of smell, but Melissa Schmitt, a researcher at the University of KwaZulu-Natal in South Africa, and her colleagues wanted to see how good they were. So she tested them at close range, using two buckets with two different hidden foods. They easily picked out the bucket with leaves from plants they enjoyed, say wild pear, and avoided ones they didn’t like, wild olive, for instance. © 2018 The New York Times Company

Keyword: Chemical Senses (Smell & Taste)
Link ID: 25105 - Posted: 06.19.2018

By JoAnna Klein You’d think that narwhals couldn’t be more enchanting. These elusive, ice-dodging, deep-diving whales have 10-foot snaggletoothed tusks, and they see with sound. But then there’s the narwhal of east Greenland. It’s kind of the narwhal of narwhals. “Because they’re so hard to access, we honestly hardly knew anything,” said Susanna Blackwell, who studies the effects of human sounds on marine mammals for Greenridge Sciences. “It’s an animal that’s been hidden from civilization for an awful long time.” Their genes are only slightly different than their western cousins. And since glaciers separated them some 10,000 years ago, this smaller population of about 6,000 narwhals, has lived relatively free from human contact amid sharp cliffs and mile-wide glaciers that break into huge, bobbing icebergs. But as the ocean warms, ice caps melt and summers get longer in the Arctic, the once inaccessible habitat of east Greenland narwhals is opening up to scientists — as well as cruise ships and prospectors interested in minerals or offshore drilling. And because toothed whales like narwhals use sounds to orient themselves, Dr. Blackwell worries this potential activity will disturb the narwhal’s acoustic way of life. So she and a team attached acoustic sensors to narwhals to monitor their behavior while human sounds are still scarce. What they found, published Wednesday in a paper in the journal PLOS One, will be used as a baseline behavior for an upcoming study to test how narwhals respond to air gun blasts similar to the ones used by oil surveyors, and may help protect them in the future. Narwhals live only in the Arctic, where it’s dark much of the time, diving thousands of feet to hunt, where it’s dark all of the time. Scientists knew they used acoustics to echolocate and communicate from studies done on narwhals in west Greenland or Canada, but they didn’t know much about the sounds of individual narwhals, especially the east Greenland population. © 2018 The New York Times Company

Keyword: Animal Communication; Hearing
Link ID: 25090 - Posted: 06.14.2018

By Matt Warren Not getting eaten is at the top of the to-do list for most members of the animal kingdom. Now, a new study suggests several species of dolphins can tell when they’re in danger of becoming a killer whale’s dinner—simply by eavesdropping on their calls. Risso’s dolphins and short-finned pilot whales are frequently devoured when they live alongside mammal-eating orcas. To find out whether the dolphins can work out when they are in danger, researchers played recordings of killer whale calls underwater to 10 pilot whales off the coast of North Carolina and four Risso’s dolphins swimming near Southern California. The animals didn’t respond to many of the killer whale sounds, but a subset of the calls provoked a strong reaction in both species: Risso’s dolphins rapidly fled, ending up more than 10 kilometers away from where the sounds were played. Pilot whales, on the other hand, called to each other and formed a tight group before diving directly toward the sound, the researchers report today in the Journal of Experimental Biology. The calls that provoked the responses all contained multiple irregular features, such as harsh and noisy sounds or two distinct frequencies at once. The researchers hypothesize that these kinds of calls could be used by groups of killer whales to communicate during hunting—a clear sign for any potential prey in the area to take action. © 2018 American Association for the Advancement of Science

Keyword: Animal Communication; Hearing
Link ID: 25082 - Posted: 06.13.2018

By David Noonan Neuroscientist James Hudspeth has basically been living inside the human ear for close to 50 years. In that time Hudspeth, head of the Laboratory of Sensory Neuroscience at The Rockefeller University, has dramatically advanced scientists’ understanding of how the ear and brain work together to process sound. Last week his decades of groundbreaking research were recognized by the Norwegian Academy of Science, which awarded him the million-dollar Kavli Prize in Neuroscience. Hudspeth shared the prize with two other hearing researchers: Robert Fettiplace from the University of Wisconsin–Madison and Christine Petit from the Pasteur Institute in Paris. Advertisement As Hudspeth explored the neural mechanisms of hearing over the years, he developed a special appreciation for the intricate anatomy of the inner ear—an appreciation that transcends the laboratory. “I think we as scientists tend to underemphasize the aesthetic aspect of science,” he says. “Yes, science is the disinterested investigation into the nature of things. But it is more like art than not. It’s something that one does for the beauty of it, and in the hope of understanding what has heretofore been hidden. Here’s something incredibly beautiful, like the inner ear, performing a really remarkable function. How can that be? How does it do it?” After learning of his Kavli Prize on Thursday, Hudspeth spoke with Scientific American about his work and how the brain transforms physical vibration into the experience of a symphony. © 2018 Scientific American

Keyword: Hearing
Link ID: 25055 - Posted: 06.04.2018