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

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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

Nicola Davis From whispering sweet nothings to hoping for sweet dreams, sugariness and pleasure have long been bound together. Now scientists studying the brains of mice have revealed why, unpicking the pathways in the brain which result in sweet foods being perceived as nice and bitter foods as nasty. What’s more, they have managed to tinker with these routes so that mice get a kick out of a tasteless substance such as water, and have even managed to switch off such judgments completely. Researchers say the finding may help with the search for treatments for eating disorders. “The very concept of sweet, the very word sweet, implies this goodness, this reward, this craving that we link to it, and similarly bitter on the other side has an immediate meaning to it. So we wanted to know, how does the brain encode meaning on sensory experience?” said Charles Zuker, lead author of the research from Columbia University’s Zuckerman Institute. Advertisement While the work was carried out in mice, Zuker said there could be parallels for the human brain and that understanding the brain circuits involved in taste and our responses to it might eventually open up the possibility of tinkering with our own responses to certain foods – including sugar cravings. © 2018 Guardian News and Media Limited

Keyword: Chemical Senses (Smell & Taste); Obesity
Link ID: 25041 - Posted: 05.31.2018

By Abby Olena Activating or suppressing neuronal activity with ultrasound has shown promise both in the lab and the clinic, based on the ability to focus noninvasive, high-frequency sound waves on specific brain areas. But in mice and guinea pigs, it appears that the technique has effects that scientists didn’t expect. In two studies published today (May 24) in Neuron, researchers demonstrate that ultrasound activates the brains of rodents by stimulating an auditory response—not, as researchers had presumed, only the specific neurons where the ultrasound is focused. “These papers are a very good warning to folks who are trying to use ultrasound as a tool to manipulate brain activity,” says Raag Airan, a neuroradiologist and researcher at Stanford University Medical Center who did not participate in either study, but coauthored an accompanying commentary. “In doing these experiments going forward [the hearing component] is something that every single experimenter is going to have to think about and control,” he adds. Over the past decade, researchers have used ultrasound to elicit electrical responses from cells in culture and motor and sensory responses from the brains of rodents and primates. Clinicians have also used so-called ultrasonic neuromodulation to treat movement disorders. But the mechanism by which high frequency sound waves work to exert their influence is not well understood. © 1986-2018 The Scientist

Keyword: Hearing
Link ID: 25025 - Posted: 05.26.2018

By Chris Buckley and Gardiner Harris BEIJING — An American government employee posted in southern China has signs of possible brain injury after reporting disturbing sounds and sensations, the State Department said on Wednesday, in events that seemed to draw parallels with mysterious ailments that struck American diplomats in Cuba. The State Department warning, issued through the United States Consulate in Guangzhou, a city in southern China, advised American citizens in China to seek medical help if they felt similar symptoms. But it said that no other cases had been reported. “A U.S. government employee in China recently reported subtle and vague, but abnormal, sensations of sound and pressure,” the health alert said. “We do not currently know what caused the reported symptoms and we are not aware of any similar situations in China, either inside or outside of the diplomatic community.” The employee was working in Guangzhou, and “reported experiencing a variety of physical symptoms” from late 2017 until April, Jinnie Lee, a spokeswoman for the United States Embassy in Beijing, said in an emailed response to questions. Secretary of State Mike Pompeo told the House Foreign Affairs Committee on Wednesday that medical teams were heading to Guangzhou to address the issue. “The medical indications are very similar and entirely consistent with the medical indications that have taken place to Americans working in Cuba,” he said. The embassy was told on Friday “that the clinical findings of this evaluation matched mild traumatic brain injury,” according to Ms. Lee, who said she could not reveal any more details to protect the employee’s privacy. Mild traumatic brain injury can show up as headache, dizziness, nausea, poor memory and a general foggy sensation. The Chinese Ministry of Foreign Affairs did not immediately answer faxed questions about the ill American, but Mr. Pompeo said the Trump administration had asked the Chinese government for assistance in an investigation, “and they have committed to honoring their commitments under the Vienna convention.” The Vienna convention requires that countries protect diplomats stationed in their nations. © 2018 The New York Times Company

Keyword: Brain Injury/Concussion; Hearing
Link ID: 25017 - Posted: 05.24.2018

By Maya Salam Three years ago, the internet melted down over the color of a dress. Now an audio file has friends, family members and office mates questioning one another’s hearing, and their own. Is the robot voice saying “Yanny” or “Laurel”? The clip picked up steam after a debate erupted on Reddit this week, and it has since been circulated widely on social media. One Reddit user said: “I hear Laurel and everyone is a liar.” “They are saying they hear ‘Yanny’ because they want attention,” a tweet read. Others claimed they heard one word for a while, then the other — or even both simultaneously. It didn’t take long for the auditory illusion to be referred to as “black magic.” And more than one person online yearned for that simpler time in 2015, when no one could decide whether the mother of the bride wore white and gold or blue and black. It was a social media frenzy in which internet trends and traffic on the topic spiked so high that Wikipedia itself now has a simple entry, “The dress.” Of course, in the grand tradition of internet reportage, we turned to a scientist to make this article legitimately newsworthy. Dr. Jody Kreiman, a principal investigator at the voice perception laboratory at the University of California, Los Angeles, helpfully guessed on Tuesday afternoon that “the acoustic patterns for the utterance are midway between those for the two words.” “The energy concentrations for Ya are similar to those for La,” she said. “N is similar to r; I is close to l.” She cautioned, though, that more analysis would be required to sort out the discrepancy. That did not stop online sleuths from trying to find the answer by manipulating the bass, pitch or volume. © 2018 The New York Times Company

Keyword: Hearing; Attention
Link ID: 24983 - Posted: 05.16.2018

By Kenneth Chang Jerrold Meinwald, who conducted pathbreaking studies of how creatures use chemicals to attract mates, repel predators and send other messages back and forth, died on April 23 at his home in Ithaca, N.Y. He was 91. His death was reported by Cornell University, where Dr. Meinwald had worked for more than 50 years. One project that Dr. Meinwald, an organic chemist, tackled soon after he arrived at Cornell in 1952 was determining what exactly in catnip drives some cats into a playful frenzy. Dr. Meinwald isolated from the plant the active ingredient — a chemical called nepetalactone — and then deduced its structure. He soon discovered an aspect of nepetalactone he had not known about. He was a giving a talk about his chemical findings, and someone had brought in a cat so he could demonstrate the effects. “It turns out not all cats respond,” Dr. Meinwald said in an interview in 2011. “I had a nonresponsive cat. The chemistry was good, but I had not realized you have to pick your subjects carefully.” Dr. Meinwald had a fruitful partnership with Thomas Eisner, an entomologist who joined the Cornell faculty in 1957. That collaboration continued for more than a half-century and established a new field of science, chemical ecology. Dr. Eisner died in 2011 at 81. Biologists had noted decades earlier that organisms produced substances that were not directly needed for the biological processes that maintain life. They suspected that these substances might be used for communications or defense. But it was only in the middle of the 20th century that chemists had the tools to study the substances in detail. © 2018 The New York Times Company

Keyword: Chemical Senses (Smell & Taste)
Link ID: 24973 - Posted: 05.15.2018

By Roni Dengler Hoary bats are habitual squawkers. Sporting frosted brown fur á la Guy Fieri, the water balloon–size bats bark high-pitched yips to navigate the dark night sky by echolocation. But a new study reveals that as they fly, those cries often drop to a whisper, or even silence, suggesting the bats may steer themselves through the darkness with some of the quietest sonar on record. To find out how hoary bats navigate, researchers used infrared cameras and ultrasonic microphones to record scores of them flying through a riverside corridor in California on five autumn nights. In about half of the nearly 80 flights, scientists captured a novel type of call. Shorter, faster, and quieter than their usual calls, the new “micro” calls use three orders of magnitude less sound energy than other bats’ yaps did, the researchers report today in the Proceedings of the Royal Society B. As bats approached objects, they would often quickly increase the volume of their calls. But in close to half the flights, researchers did not pick up any calls at all. This stealth flying mode may explain one sad fact of hoary bat life: They suffer more fatal run-ins with wind turbines than other bat species in North America. The microcalls are so quiet that they reduce the distance over which bats can detect large and small objects by more than three times. That also cuts bats’ reaction time by two-thirds, making them too slow to catch their insect prey. © 2018 American Association for the Advancement of Science

Keyword: Hearing
Link ID: 24928 - Posted: 05.02.2018

Helen Thompson In the pitch-black waters beneath the Arctic ice, bowhead whales get funky. A small population of endangered bowheads belt an unusually varied repertoire of songs, which grows more diverse during mating season. Hunted to near extinction in the 1600s, these fire truck–sized mammals now number in the 300s in the frigid waters around the Svalbard archipelago in Norway. Underwater audio recorders captured the whales singing 184 acoustically distinct songs from October to April in 2010 through 2014. On the bowhead charts, a song's popularity is fleeting. Most recorded songs were heard for less than 100 hours total, although one song registered over 730 hours total. Some songs appeared in more than one month, but none repeated annually. December and January, likely the height of breeding season, saw a wider array of new bowhead songs than other months, researchers report in the April Biology Letters. Hearing a more distinct mixtape may play a role in enticing a female to mate. A hot cetacean band The Spitzbergen bowhead whale songbook contains a wide variety of tunes, and some stick around on the charts longer than others. Here each bubble corresponds to one of the 184 songs recorded by researchers from 2010 to 2014. The size of the bubble corresponds to the number of hours it was sung. Click on any of the dark green bubbles to hear that whale’s song. Groups of humpback whales don't change their tunes much in a given year, compared with bowheads. Only a few songbird species boast similar diversity. © Society for Science & the Public 2000 - 2018.

Keyword: Animal Communication; Sexual Behavior
Link ID: 24927 - Posted: 05.01.2018

By Abby Olena At both three and nine weeks after guinea pigs’ cochleae were treated with nanoparticles loaded with Hes1 siRNA, the authors observed what are likely immature hair cells. MODIFIED FROM X. DU ET AL., MOLECULAR THERAPY, 2018Loud sounds, infections, toxins, and aging can all cause hearing loss by damaging so-called hair cells in the cochlea of the inner ear. In a study published today (April 18) in Molecular Therapy, researchers stimulated hair cell renewal with small interfering RNAs (siRNAs) delivered via nanoparticles to the cochlea of adult guinea pigs, restoring some of the animals’ hearing. “There are millions of people suffering from deafness” caused by hair cell loss, says Zheng-Yi Chen, who studies hair cell regeneration at Harvard University and was not involved in the work. “If you can regenerate hair cells, then we really have potential to target treatment for those patients.” Some vertebrates—chickens and zebrafish, for instance—regenerate their hair cells after damage. Hair cells of mammals, on the other hand, don’t sprout anew after being damaged, explaining why injuries can cause life-long hearing impairments. Recent research suggests that there might be a workaround, by manipulating signaling pathways that can lead to hair cell differentiation. That’s where Richard Kopke comes in. © 1986-2018 The Scientist

Keyword: Hearing
Link ID: 24908 - Posted: 04.27.2018