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

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Shawna Williams The sensation of perceiving a smell can be induced in people by using electrodes to stimulate the brain’s olfactory bulb, researchers report today (November 27) in the International Forum of Allergy & Rhinology. The results, they suggest, are a proof of concept that it would be possible to develop an “olfactory implant system” to aid people with an impaired sense of smell, known as anosmia. “Our work shows that smell restoration technology is an idea worth studying further,” says coauthor Eric Holbrook of Massachusetts Eye and Ear Infirmary in a press release. “The development of cochlear implants, for example, didn’t really accelerate until someone placed an electrode in the cochlea of a patient and found that the patient heard a frequency of some type.” Holbrook and colleagues enrolled five subjects in the study who were able to smell. Three of them reported perceiving odors not actually present when the researchers stimulated different parts of their olfactory bulbs with electrodes inserted through the nose, a procedure the study authors say caused “minimal discomfort.” Subjects described the smells as “onion-like,” “antiseptic-like,” “sour,” “fruity,” or simply “bad.” The finding follows a report earlier this year that electrically stimulating structures high up in the nasal cavity produced smell sensations. The scientists who conducted that study at Malaysia’s Imagineering Institute aim to one day transmit smells electronically, reportes IEEE Spectrum—for example, to give restaurant-goers a whiff of dishes on the menu as they decide what to order. © 1986 - 2018 The Scientist

Keyword: Chemical Senses (Smell & Taste)
Link ID: 25726 - Posted: 11.29.2018

Tina Hesman Saey Whether people prefer coffee or tea may boil down to a matter of taste genetics. People with a version of a gene that increases sensitivity to the bitter flavor of caffeine tend to be coffee drinkers, researchers report online November 15 in Scientific Reports. Tea drinkers tended to be less sensitive to caffeine’s bitter taste, but have versions of genes that increase sensitivity to the bitterness of other chemicals, the researchers found. It’s long been thought that people avoid eating bitter foods because bitterness is an indicator of poison, says John Hayes, a taste researcher at Penn State who was not involved in the study. The coffee and tea findings help challenge that “overly simplistic ‘bitter is always bad, let’s avoid it’” view, he says. In the new study, researchers examined DNA variants of genes involved in detecting the bitter taste of the chemicals, caffeine, quinine — that bitter taste in tonic water — and propylthiouracil (PROP), a synthetic chemical not naturally found in food or drink. Other bitter components naturally in coffee and tea may trigger the same taste responses as quinine and PROP do, Hayes says. Researchers in Australia, the United States and England examined DNA from more than 400,000 participants in the UK Biobank, a repository of genetic data for medical research. Participants also reported other information about their health and lifestyle, including how much tea or coffee they drink each day. |© Society for Science & the Public 2000 - 2018

Keyword: Chemical Senses (Smell & Taste); Genes & Behavior
Link ID: 25693 - Posted: 11.16.2018

Jennifer Leman Some moths aren’t so easy for bats to detect. The cabbage tree emperor moth has wings with tiny scales that absorb sound waves sent out by bats searching for food. That absorption reduces the echoes that bounce back to bats, allowing Bunaea alcinoe to avoid being so noticeable to the nocturnal predators, researchers report online November 12 in the Proceedings of the National Academy of Sciences. “They have this stealth coating on their body surfaces which absorbs the sound,” says study coauthor Marc Holderied, a bioacoustician at the University of Bristol in England. “We now understand the mechanism behind it.” Bats sense their surroundings using echolocation, sending out sound waves that bounce off objects and return as echoes picked up by the bats’ supersensitive ears (SN: 9/30/17, p. 22). These moths, without ears that might alert them to an approaching predator, have instead developed scales of a size, shape and thickness suited to absorbing ultrasonic sound frequencies used by bats, the researchers found. The team shot ultrasonic sound waves at a single, microscopic scale and observed it transferring sound wave energy into movement. The scientists then simulated the process with a 3-D computer model that showed the scale absorbing up to 50 percent of the energy from sound waves. What’s more, it isn’t just wings that help such earless moths evade bats. Other moths in the same family as B. alcinoe also have sound-absorbing fur, the same researchers report online October 18 in the Journal of the Acoustical Society of America. |© Society for Science & the Public 2000 - 2018

Keyword: Hearing; Evolution
Link ID: 25679 - Posted: 11.14.2018

By JoAnna Klein Lavender bath bombs; lavender candles; deodorizing lavender sachets for your shoes, car or underwear drawer; lavender diffusers; lavender essential oils; even lavender chill pills for humans and dogs. And from Pinterest: 370 recipes for lavender desserts. Take a deep breath. Release. People like lavender. We’ve been using this violet-capped herb since at least medieval times. It smells nice. But Google “lavender” and results hint at perhaps the real fuel for our obsession: “tranquillity,” “calm,” “relaxation,” “soothing,” and “serenity.” Lavender has purported healing powers for reducing stress and anxiety. But are these effects more than just folk medicine? Yes, said Hideki Kashiwadani, a physiologist and neuroscientist at Kagoshima University in Japan — at least in mice. “Many people take the effects of ‘odor’ with a grain of salt,” he said in an email. “But among the stories, some are true based on science.” In a study published Tuesday in the journal Frontiers in Behavioral Neuroscience, he and his colleagues found that sniffing linalool, an alcohol component of lavender odor, was kind of like popping a Valium. It worked on the same parts of a mouse’s brain, but without all the dizzying side effects. And it didn’t target parts of the brain directly from the bloodstream, as was thought. Relief from anxiety could be triggered just by inhaling through a healthy nose. Their findings add to a growing body of research demonstrating anxiety-reducing qualities of lavender odors and suggest a new mechanism for how they work in the body. Dr. Kashiwadani believes this new insight is a key step in developing lavender-derived compounds like linalool for clinical use in humans. Dr. Kashiwadani and his colleagues became interested in learning how linalool might work for anti-anxiety while testing its effects on pain relief in mice. In this earlier study, they noticed that the presence of linalool seemed to calm mice. © 2018 The New York Times Company

Keyword: Emotions; Chemical Senses (Smell & Taste)
Link ID: 25610 - Posted: 10.24.2018

Allison Aubrey By age 40, about one in 10 adults will experience some hearing loss. It happens so slowly and gradually, says audiologist Dina Rollins, "you don't realize what you're missing." And even as it worsens, many people are in denial. By the time someone is convinced they have a hearing problem, age-related memory loss may have already set in. But, here's the good news: Restoring hearing with hearing aids can help slow down cognitive decline. Consider these findings: Researchers tracked about 2,000 older adults in the U.S. both before and after they started using hearing aids. The adults were participants in a big, national study, the Health and Retirement Study. "We found the rate of cognitive decline was slowed by 75 percent following the adoption of hearing aids," says Asri Maharani, a researcher at the University of Manchester in the division of neuroscience and experimental psychology and an author of the paper. "It is a surprising result," Maharani says. The study was published this spring in the Journal of the American Geriatrics Society. To assess cognition over time, researchers performed a battery of tests face-to-face with participants. This was done every two years from 1996 to 2014. One test to assess memory required participants to recall a list of 10 words, both immediately after the words were read aloud, and then again after the participants had been distracted by other tasks. © 2018 npr

Keyword: Alzheimers; Development of the Brain
Link ID: 25599 - Posted: 10.22.2018

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