Ari Daniel On a dark night in northern Belize in early May, Gliselle Marin stands in the middle of a patchy forest in the Lamanai Archaeological Reserve, about a two-hour drive from where she grew up. Every few minutes, she and her fellow researchers sweep their headlamps over the nets they’ve strung up to see if they’ve caught anything. Before long, a chirping leaf-nosed bat the color of hot cocoa is entangled. He’s small — about the size of a lemon. Marin works carefully and quickly to free him. “We’re trying to get the net off of him,” she says. “It’s kind of like a puzzle. I like to take the feet out first. And then I do one wing, then the head.” Within a minute, the tiny bat is out. Marin jots down some basic information about the bat and then places him inside a cloth bag for further study that night. All the tools Marin needs for this kind of delicate extraction — including an ordinary crochet hook, for the worst tangles — fit into a fanny pack that’s adorned with little printed bats. The scientist also sports bat earrings, as well as a tattoo of small bats flying up the nape of her neck. Marin is a biology PhD student at York University in Toronto, and she’s here with the “Bat-a-thon,” a group of 80-some bat researchers who converge on this part of Belize each year to study these winged mammals. Growing up, Marin’s family had bats roosting under their house. “But when I actually started working with them and realizing we have close to 80 species of bats,” she says, “I was like, ‘Okay, it’s kind of crazy that I’ve been in science my whole life and was never taught that we have this diversity of bats in Belize.’” Over time, she’s come to admire not just the cornucopia of species, but the spectacular array of abilities and behaviors of these adaptable little animals. Scientists, she says, have only scratched the surface when it comes to understanding these furry, flying mammals. © 2024 npr

Related chapters from BN: Chapter 9: Hearing, Balance, Taste, and Smell
Related chapters from MM:Chapter 6: Hearing, Balance, Taste, and Smell
Link ID: 29429 - Posted: 08.13.2024

By Elena Kazamia It was a profound moment of connection. Carlos Casas could feel the elephant probing him, touching him with sound. The grunts emanating from the large male were of a frequency too low to hear, but Casas felt an agitation on his skin and deep inside his chest. “I was being scanned,” he says. At the time of the encounter, Casas was filming a project in Sri Lanka, and was holding a camera. But his interactions with the elephant gave the Catalonian filmmaker and installation artist an idea: What if instead of relying on images alone, he could use sound to create a physical connection between an audience of people and the subjects that fascinate him most, the animals with which we share life on this planet? Bestiari, his audio-visual project, now on display inside a former shipping warehouse at the Venice Biennale, weaves an immersive landscape for visitors. (You can explore some of the project, which was curated by Filipa Ramos, at the Instagram page for the installation.) Audio of the sounds the animals make is accompanied by video collected from remote camera traps set across national parks of Catalonia and Kenya, together with abstract film meant to capture the world as the animals see it, based on a combination of scientific research and artistic license. A series of texts serve as field guides to each animal featured in the installation. Entering the dark warehouse where Bestiari is housed, you are invited to lie on the floor, as if to fall asleep, before communing with seven different species: bees, donkeys, parakeets, snakes, bats, dolphins, and elephants. Each of the chosen species is represented by a speaker, customized to deliver the desired acoustics. Casas calls the speakers, “Trojan horses of meaning and communication.” The pitches and volumes were curated to be authentic to the original animal but perceptible by humans. For example, the echolocation chirps of bats have been slowed down to showcase the tonal progression of the sound. © 2024 NautilusNext Inc.,

Related chapters from BN: Chapter 9: Hearing, Balance, Taste, and Smell; Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 6: Hearing, Balance, Taste, and Smell; Chapter 5: The Sensorimotor System
Link ID: 29421 - Posted: 08.03.2024

By Hannah Richter Humans aren’t the only animals that lose hearing as they grow older. Almost every mammal studied struggles to pick up some sounds as they age. Some veterinarians even fit dogs for tiny hearing aids. But at least one species of bat appears to be an exception. Reporting this month on the preprint server bioRxiv, scientists have discovered that big brown bats (Eptesicus fuscus) don’t hear any worse as they grow older, possibly because their ability to echolocate is so critical to their survival. “Hearing is kind of their superpower,” says Mirjam Knörnschild, a behavioral ecologist at the Museum of Natural History Berlin who was not involved with the work. The research, she and others say, could lead to new ways to understand—and possibly treat—hearing loss in humans. Bats actually have two superpowers. Not only can most of them echolocate—bouncing sound off objects to hunt and navigate—they also tend to be remarkably long-lived for their size. Most small mammals are short-lived, but compared with mice of similar stature, the big brown bat lives up to five times as long, sometimes topping out at 19 years old. That makes the species a fascinating target for studies of aging, says Grace Capshaw, a postdoctoral researcher at Johns Hopkins University. The bat auditory system is fundamentally the same as that of every other mammal, she says, so “bats can be a really powerful model for comparing how hearing works.” To test whether big brown bats lose their hearing over time, Capshaw and colleagues divided 23 wild-caught bats into groups of young and old, making 6 years—the mean age of the species—the dividing line. The researchers determined the bats’ ages using a precise genetic method that involves comparing each animal’s DNA with the DNA of bats with known ages. They then sedated the animals to conduct a hearing examination similar to those done on human infants.

Related chapters from BN: Chapter 9: Hearing, Balance, Taste, and Smell; Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 6: Hearing, Balance, Taste, and Smell; Chapter 5: The Sensorimotor System
Link ID: 29411 - Posted: 07.31.2024

Ian Sample Science editor Five children who were born deaf now have hearing in both ears after taking part in an “astounding” gene therapy trial that raises hopes for further treatments. The children were unable to hear because of inherited genetic mutations that disrupt the body’s ability to make a protein needed to ensure auditory signals pass seamlessly from the ear to the brain. Doctors at Fudan University in Shanghai treated the children, aged between one and 11, in both ears in the hope they would gain sufficient 3D hearing to take part in conversations and work out which direction sounds were coming from. Within weeks of receiving the therapy, the children had gained hearing, could locate the sources of sounds, and recognised speech in noisy environments. Two of the children were recorded dancing to music, the researchers reported in Nature Medicine. A child facing away from the camera towards a panel of auditory testing equipment with script in the top left corner Dr Zheng-Yi Chen, a scientist at Massachusetts Eye and Ear, a Harvard teaching hospital in Boston that co-led the trial, said the results were “astounding”, adding that researchers continued to see the children’s hearing ability “dramatically progress”. The therapy uses an inactive virus to smuggle working copies of the affected gene, Otof, into the inner ear. Once inside, cells in the ear use the new genetic material as a template to churn out working copies of the crucial protein, otoferlin. Video footage of the patients shows a two-year-old boy responding to his name three weeks after the treatment and dancing to music after 13 weeks, having shown no response to either before receiving the injections. © 2024 Guardian News & Media Limited

Related chapters from BN: Chapter 9: Hearing, Balance, Taste, and Smell; Chapter 19: Language and Lateralization
Related chapters from MM:Chapter 6: Hearing, Balance, Taste, and Smell; Chapter 15: Language and Lateralization
Link ID: 29347 - Posted: 06.06.2024

By Jordan Pearson Engineers and scientists have an enduring fascination with spider silk. Similar to typical worm silk that makes for comfy bedsheets, but much tougher, the material has inspired the invention of lighter and more breathable body armor and materials that could make airplane components stronger without adding weight. Researchers are even using examples drawn from spider webs to design sensitive microphones that can one day be used to treat hearing loss and deafness and to improve other listening devices. Spiders use their webs like enormous external eardrums. A team of scientists from Binghamton University and Cornell University reported in 2022 that webs allow arachnids to detect sound from 10 feet away. When you hear a sound through your ear, what you’re really experiencing are changes in air pressure that cause your eardrum to vibrate. This is how microphones work: by mimicking the human ear and vibrating in response to pressure. Instead of vibrating when hit by a wave of pressure like a stick hitting a drumhead, they move with the flow of the air being displaced. Air is a fluid medium “like honey,” said Ronald Miles, a professor of mechanical engineering at Binghamton. Humans navigate this environment without noticing much resistance, but silk fibers are buffeted about by the velocity of the viscous forces in air. Dr. Miles couldn’t help but wonder if this principle could lead to a new kind of microphone. “Humans are kind of arrogant animals,” he said. “They make devices that work like they do.” But he wondered about building a device to be more like a spider and sense “sound with the motion of the air.” © 2024 The New York Times Company

Related chapters from BN: Chapter 9: Hearing, Balance, Taste, and Smell
Related chapters from MM:Chapter 6: Hearing, Balance, Taste, and Smell
Link ID: 29310 - Posted: 05.18.2024

By Jake Buehler Sounding like a toxic moth might keep some beetles safe from hungry bats. When certain tiger beetles hear an echolocating bat draw near, they respond with extremely high-pitched clicks. This acoustic countermeasure is a dead ringer for the noises toxic moths make to signal their nasty taste to bats, researchers report May 15 in Biology Letters. Such sound-based mimicry may be widespread among groups of night-flying insects, the scientists say. At night, bats and bugs are locked in sonic warfare. At least seven major insect groups have ears sensitive to bat echolocation pitches, and many often flee in response. Some moths have sound-absorbent wings and fuzz that impart stealth against bat sonar (SN: 11/14/18). Others use their genitals to make ultrasonic trills — above the range of human hearing — that may startle bats or jam their sonar (SN: 7/3/13). Previous research suggested some tiger beetles — a family of fast-running, often strikingly colored predatory beetles with strong jaws — also make high-pitched clicks as a response to human-made imitations of bat ultrasound. So Harlan Gough, a conservation entomologist now at the U.S. Fish and Wildlife Service in Burbank, Wash., and his colleagues set out to answer why. The researchers collected 19 tiger beetle species from southern Arizona and brought them into the lab. They tethered the insects to a metal rod and prompted them to fly. The team then filmed and recorded audio to see how the beetles responded to playback of a bat clicking sequence that immediately precedes an attack. Right away, seven of these species — all nocturnal fliers — pulled their hard, case-like forewings into the path of their beating hindwings. The resulting collisions made high-pitched clicking noises. © Society for Science & the Public 2000–2024.

Related chapters from BN: Chapter 9: Hearing, Balance, Taste, and Smell; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 6: Hearing, Balance, Taste, and Smell
Link ID: 29308 - Posted: 05.16.2024

Andrew Gregory Health editor A British toddler has had her hearing restored after becoming the first person in the world to take part in a pioneering gene therapy trial, in a development that doctors say marks a new era in treating deafness. Opal Sandy was born unable to hear anything due to auditory neuropathy, a condition that disrupts nerve impulses travelling from the inner ear to the brain and can be caused by a faulty gene. But after receiving an infusion containing a working copy of the gene during groundbreaking surgery that took just 16 minutes, the 18-month-old can hear almost perfectly and enjoys playing with toy drums. Her parents were left “gobsmacked” when they realised she could hear for the first time after the treatment. “I couldn’t really believe it,” Opal’s mother, Jo Sandy, said. “It was … bonkers.” The girl, from Oxfordshire, was treated at Addenbrooke’s hospital, part of Cambridge university hospitals NHS foundation trust, which is running the Chord trial. More deaf children from the UK, Spain and the US are being recruited to the trial and will all be followed up for five years. Prof Manohar Bance, an ear surgeon at the trust and chief investigator for the trial, said the initial results were “better than I hoped or expected” and could cure patients with this type of deafness. “We have results from [Opal] which are very spectacular – so close to normal hearing restoration. So we do hope it could be a potential cure.” He added: “There’s been so much work, decades of work … to finally see something that actually worked in humans …. It was quite spectacular and a bit awe-inspiring really. It felt very special.” Auditory neuropathy can be caused by a fault in the OTOF gene, which makes a protein called otoferlin. This enables cells in the ear to communicate with the hearing nerve. To overcome the fault, the new therapy from biotech firm Regeneron sends a working copy of the gene to the ear. © 2024 Guardian News & Media Limited

Related chapters from BN: Chapter 9: Hearing, Balance, Taste, and Smell
Related chapters from MM:Chapter 6: Hearing, Balance, Taste, and Smell
Link ID: 29300 - Posted: 05.09.2024

By Gina Kolata At 7 p.m. on May 7, 1824, Ludwig van Beethoven, then 53, strode onto the stage of the magnificent Theater am Kärntnertor in Vienna to help conduct the world premiere of his Ninth Symphony, the last he would ever complete. That performance, whose 200th anniversary is on Tuesday, was unforgettable in many ways. But it was marked by an incident at the start of the second movement that revealed to the audience of about 1,800 people how deaf the revered composer had become. Ted Albrecht, a professor emeritus of musicology at Kent State University in Ohio and author of a recent book on the Ninth Symphony, described the scene. The movement began with loud kettledrums, and the crowd cheered wildly. But Beethoven was oblivious to the applause and his music. He stood with his back to the audience, beating time. At that moment, a soloist grasped his sleeve and turned him around to see the raucous adulation he could not hear. It was one more humiliation for a composer who had been mortified by his deafness since he had begun to lose his hearing in his twenties. But why had he gone deaf? And why was he plagued by unrelenting abdominal cramps, flatulence and diarrhea? A cottage industry of fans and experts has debated various theories. Was it Paget’s disease of bone, which in the skull can affect hearing? Did irritable bowel syndrome cause his gastrointestinal problems? Or might he have had syphilis, pancreatitis, diabetes or renal papillary necrosis, a kidney disease? After 200 years, a discovery of toxic substances in locks of the composer’s hair may finally solve the mystery. © 2024 The New York Times Company

Related chapters from BN: Chapter 9: Hearing, Balance, Taste, and Smell; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 6: Hearing, Balance, Taste, and Smell; Chapter 4: Development of the Brain
Link ID: 29293 - Posted: 05.07.2024

Sofia Quaglia Noise pollution from traffic stunts growth in baby birds, even while inside the egg, research has found. Unhatched birds and hatchlings that are exposed to noise from city traffic experience long-term negative effects on their health, growth and reproduction, the study found. “Sound has a much stronger and more direct impact on bird development than we knew before,” said Dr Mylene Mariette, a bird communication expert at Deakin University in Australia and a co-author of the study, published in the journal Science. “It would be wise to work more to reduce noise pollution.” A growing body of research has suggested that noise pollution causes stress to birds and makes communication harder for them. But whether birds are already distressed at a young age because they are affected by noise, or by how noise disrupts their environment and parental care, was still unclear. Mariette’s team routinely exposed zebra finch eggs for five days to either silence, soothing playbacks of zebra finch songs, or recordings of city traffic noises such as revving motors and cars driving past. They did the same with newborn chicks for about four hours a night for up to 13 nights, without exposing the birds’ parents to the sounds. They noticed that the bird eggs were almost 20% less likely to hatch if exposed to traffic noise. The chicks that did hatch were more than 10% smaller and almost 15% lighter than the other hatchlings. When the team ran analyses on their red blood cells and their telomeres – a piece of DNA that shortens with stress and age – they were more eroded and shorter than their counterparts’. The effects continued even after the chicks were no longer exposed to noise pollution, and carried over into their reproductive age four years later. The birds disturbed by noise during the early stages of their lives produced fewer than half as many offspring as their counterparts. © 2024 Guardian News & Media Limited

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 9: Hearing, Balance, Taste, and Smell
Related chapters from MM:Chapter 13: Memory and Learning; Chapter 6: Hearing, Balance, Taste, and Smell
Link ID: 29273 - Posted: 04.26.2024

Allison Aubrey Imagine if every moment is filled with a high-pitched buzz or ring that you can't turn off. More than 25 million adults in the U.S., have a condition called tinnitus, according to the American Tinnitus Association. It can be stressful, even panic-inducing and difficult to manage. Dozens of factors can contribute to the onset of tinnitus, including hearing loss, exposure to loud noise or a viral illness. There's no cure, but there are a range of strategies to reduce the symptoms and make it less bothersome, including hearing aids, mindfulness therapy, and one newer option – a device approved by the FDA to treat tinnitus using electrical stimulation of the tongue. The device has helped Victoria Banks, a singer and songwriter in Nashville, Tenn., who developed tinnitus about three years ago. "The noise in my head felt like a bunch of cicadas," Banks says. "It was terrifying." The buzz made it difficult for her to sing and listen to music. "It can be absolutely debilitating," she says. Banks tried taking dietary supplements, but those didn't help. She also stepped up exercise, but that didn't bring relief either. Then she read about a device called Lenire, which was approved by the FDA in March 2023. It includes a plastic mouthpiece with stainless steel electrodes that electrically stimulate the tongue. It is the first device of its kind to be approved for tinnitus. "This had worked for other people, and I thought I'm willing to try anything at this point," Banks recalls. She sought out audiologist Brian Fligor, who treats severe cases of tinnitus in the Boston area. Fligor was impressed by the results of a clinical trial that found 84% of participants who tried Lenire experienced a significant reduction in symptoms. He became one of the first providers in the U.S. to use the device with his patients. Fligor also served on an advisory panel assembled by the company who developed it. © 2024 npr

Related chapters from BN: Chapter 9: Hearing, Balance, Taste, and Smell
Related chapters from MM:Chapter 6: Hearing, Balance, Taste, and Smell
Link ID: 29259 - Posted: 04.16.2024

By Lisa Sanders, M.D. “We were thinking about going bowling with the kids tomorrow,” the woman told her 43-year-old brother as they settled into their accustomed spots in the living room of their mother’s home in Chicago. It was late — nearly midnight — and he had arrived from Michigan to spend the days between Christmas and New Year’s with this part of his family. She and her husband and her brother grew up together and spent many late nights laughing and talking. She knew her brother was passionate about bowling. He had spent almost every day in his local alley two summers ago. So she was taken by surprise when he answered, “I can’t do that anymore.” Certainly, her brother had had a tough year. It seemed to start with his terrible heartburn. For most of his life, he had what he described as run-of-the-mill heartburn, usually triggered by eating late at night, and he would have to take a couple of antacid tablets. But that year his heartburn went ballistic. His mouth always tasted like metal. And the reflux of food back up the esophagus would get so bad that it would make him vomit. Nothing seemed to help. He quit drinking coffee. Quit drinking alcohol. Stopped eating spicy foods. He told his doctor, who started him on a medication known as a proton pump inhibitor (P.P.I.) to reduce the acid or excess protons his stomach made. That pill provided relief from the burning pain. But he still had the metallic taste in his mouth, still felt sick after eating. He still vomited several times a week. When he discovered that he wouldn’t throw up when he drank smoothies, he almost completely gave up solid foods. When he was still feeling awful after weeks on the P.P.I., his gastroenterologist used a tiny camera to take a look at his esophagus. His stomach looked fine, but the region where the esophagus entered the stomach was a mess. Normally the swallowing tube ends with a tight sphincter that stays closed to protect delicate tissue from the harsh acid of the stomach. It opens when swallowing, to let the food pass. But his swallowing tube was wide open and the tissue around the sphincter was red and swollen. © 2024 The New York Times Company

Related chapters from BN: Chapter 9: Hearing, Balance, Taste, and Smell
Related chapters from MM:Chapter 6: Hearing, Balance, Taste, and Smell
Link ID: 29137 - Posted: 02.08.2024

By Gina Kolata Aissam Dam, an 11-year-old boy, grew up in a world of profound silence. He was born deaf and had never heard anything. While living in a poor community in Morocco, he expressed himself with a sign language he invented and had no schooling. Last year, after moving to Spain, his family took him to a hearing specialist, who made a surprising suggestion: Aissam might be eligible for a clinical trial using gene therapy. On Oct. 4, Aissam was treated at the Children’s Hospital of Philadelphia, becoming the first person to get gene therapy in the United States for congenital deafness. The goal was to provide him with hearing, but the researchers had no idea if the treatment would work or, if it did, how much he would hear. The treatment was a success, introducing a child who had known nothing of sound to a new world. “There’s no sound I don’t like,” Aissam said, with the help of interpreters during an interview last week. “They’re all good.” While hundreds of millions of people in the world live with hearing loss that is defined as disabling, Aissam is among those whose deafness is congenital. His is an extremely rare form, caused by a mutation in a single gene, otoferlin. Otoferlin deafness affects about 200,000 people worldwide. The goal of the gene therapy is to replace the mutated otoferlin gene in patients’ ears with a functional gene. Although it will take years for doctors to sign up many more patients — and younger ones — to further test the therapy, researchers said that success for patients like Aissam could lead to gene therapies that target other forms of congenital deafness. © 2024 The New York Times Company

Related chapters from BN: Chapter 9: Hearing, Balance, Taste, and Smell
Related chapters from MM:Chapter 6: Hearing, Balance, Taste, and Smell
Link ID: 29119 - Posted: 01.27.2024

By Shaena Montanari Around 2012, Jennifer Groh and her colleagues began a series of experiments investigating the effect of eye movements on auditory signals in the brain. It wasn’t until years later that they noticed something curious in their data: In both an animal model and in people, eye movements coincide with ripples across the eardrum. The finding, published in 2018, seemed “weird,” says Groh, professor of psychology and neuroscience at Duke University — and ripe for further investigation. “You can go your whole career never studying something that is anywhere near as beautifully regular and reproducible,” she says. “Signals that are really robust are unlikely to be just random.” A new experiment from Groh’s lab has now taken her observation a step further and suggests the faint sounds — dubbed “eye movement-related eardrum oscillations,” or EMREOs for short — serve to link two sensory systems. The eardrum oscillations contain “clean and precise” information about the direction of eye movements and, according to Groh’s working hypothesis, help animals connect sound with a visual scene. “The basic problem is that the way we localize visual information and the way we localize sounds leads to two different reference frames,” Groh says. EMREOs, she adds, play a part in relating those frames. The brain, and not the eyes, must generate the oscillations, Groh and her colleagues say, because they happen at the same time as eye movements, or sometimes even before. To learn more about the oscillations, the team placed small microphones in the ears of 10 volunteers, who then performed visual tasks while the researchers tracked their eye movements. The group published their results in Proceedings of the National Academy of Sciences in November. © 2024 Simons Foundation

Related chapters from BN: Chapter 9: Hearing, Balance, Taste, and Smell
Related chapters from MM:Chapter 6: Hearing, Balance, Taste, and Smell
Link ID: 29115 - Posted: 01.27.2024

Allison Aubrey Among the roughly 40 million adults in the U.S. who have hearing loss, most don't use hearing aids. This means they may be missing out on more than just good hearing. Research shows hearing loss, if left untreated, can increase the risk of frailty, falls, social isolation, depression and cognitive decline. One study from scientists at Johns Hopkins University found that even people with mild hearing loss doubled their risk of dementia. Now a new study finds that restoring hearing loss with hearing aids may lengthen people's lives. Dr. Janet Choi, an otolaryngologist with Keck Medicine of USC, wanted to evaluate whether restoring hearing with hearing aids may increase the chances of living longer. Using data from the the National Health and Nutrition Examination Survey, a large, national study, Choi and her colleagues tracked the status of nearly 1,900 adults who had been shown to have hearing loss during screenings. The participants completed questionnaires about their use of hearing aids. "The group of patients who were using hearing aids regularly had a 24% lower risk of mortality compared to the group who never use hearing aids," Choi says. Meaning, the participants who were in the habit of wearing hearing aids were significantly less likely to die early. The researchers had hypothesized this would be the case given all the studies pointing to the negative impacts of untreated hearing loss. But Choi says they did not expect such a big difference in mortality risk. "We were surprised," she says. Prior research has shown that age-related hearing loss – if untreated – can take its toll on physical and mental health. And a recent study found restoring hearing with hearing aids may slow cognitive decline among people at high risk. © 2024 npr

Related chapters from BN: Chapter 9: Hearing, Balance, Taste, and Smell
Related chapters from MM:Chapter 6: Hearing, Balance, Taste, and Smell
Link ID: 29079 - Posted: 01.06.2024

By Henkjan Honing In 2009, my research group found that newborns possess the ability to discern a regular pulse— the beat—in music. It’s a skill that might seem trivial to most of us but that’s fundamental to the creation and appreciation of music. The discovery sparked a profound curiosity in me, leading to an exploration of the biological underpinnings of our innate capacity for music, commonly referred to as “musicality.” In a nutshell, the experiment involved playing drum rhythms, occasionally omitting a beat, and observing the newborns’ responses. Astonishingly, these tiny participants displayed an anticipation of the missing beat, as their brains exhibited a distinct spike, signaling a violation of their expectations when a note was omitted. Yet, as with any discovery, skepticism emerged (as it should). Some colleagues challenged our interpretation of the results, suggesting alternate explanations rooted in the acoustic nature of the stimuli we employed. Others argued that the observed reactions were a result of statistical learning, questioning the validity of beat perception being a separate mechanism essential to our musical capacity. Infants actively engage in statistical learning as they acquire a new language, enabling them to grasp elements such as word order and common accent structures in their native language. Why would music perception be any different? To address these challenges, in 2015, our group decided to revisit and overhaul our earlier beat perception study, expanding its scope, method and scale, and, once more, decided to include, next to newborns, adults (musicians and non-musicians) and macaque monkeys. The results, recently published in Cognition, confirm that beat perception is a distinct mechanism, separate from statistical learning. The study provides converging evidence on newborns’ beat perception capabilities. In other words, the study was not simply a replication but utilized an alternative paradigm leading to the same conclusion. © 2023 NautilusNext Inc., All rights reserved.

Related chapters from BN: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 14: Attention and Higher Cognition
Link ID: 29067 - Posted: 12.27.2023

By Esther Landhuis When Frank Lin was in junior high, his grandma started wearing hearing aids. During dinner conversations, she was often painfully silent, and communicating by phone was nearly impossible. As a kid, Lin imagined “what her life would be like if she wasn’t always struggling to communicate.” It was around that time that Lin became interested in otolaryngology, the study of the ears, nose, and throat. He would go on to study to be an ENT physician, which, he hoped, could equip him to help patients with similar age-related hardships. Those aspirations sharpened during his residency at Johns Hopkins University School of Medicine in the late 2000s. Administering hearing tests in the clinic, Lin noticed that his colleagues had vastly different reactions to the same results in young versus old patients. If mild deficits showed up in a kid, “it would be like, ‘Oh, that hearing is critically important,’” said Lin, who today is the director of the Cochlear Center for Hearing and Public Health at Hopkins. But when they saw that same mild to moderate hearing loss in a 70-something patient, many would downplay the findings. Yet today, research increasingly suggests that untreated hearing loss puts people at higher risk for cognitive decline and dementia. And, unlike during Lin’s early training, many patients can now do something about it: They can assess their own hearing using online tests or mobile phone apps, and purchase over-the-counter hearing aids, which are generally more affordable their predecessors and came under regulation by the Food and Drug Administration in October 2022. Despite this expanded accessibility, interest in direct-to-consumer hearing devices has lagged thus far — in part, experts suggest, due to physician inattention to adult hearing health, inadequate insurance coverage for hearing aids, and lingering stigma around the issue. (As Lin put it: “There’s always been this notion that everyone has it as you get older, how can it be important?”) Even now, hearing tests aren’t necessarily recommended for individuals unless they report a problem.

Related chapters from BN: Chapter 9: Hearing, Balance, Taste, and Smell; Chapter 19: Language and Lateralization
Related chapters from MM:Chapter 6: Hearing, Balance, Taste, and Smell; Chapter 15: Language and Lateralization
Link ID: 29064 - Posted: 12.27.2023

By Carolyn Wilke Newborn bottlenose dolphins sport a row of hairs along the tops of their jaws. But once the animals are weaned, the whiskers fall out. “Everybody thought these structures are vestigial — so without any function,” said Guido Dehnhardt, a marine mammal zoologist at the University of Rostock in Germany. But Dr. Dehnhardt and his colleagues have discovered that the pits left by those hairs can perceive electricity with enough sensitivity that they may help the dolphins snag fish or navigate the ocean. The team reported its findings Thursday in The Journal of Experimental Biology. Dr. Dehnhardt first studied the whisker pits of a different species, the Guiana dolphin. He expected to find the typical structures of hair follicles, but those were missing. Yet the pits were loaded with nerve endings. He and his colleagues realized that the hairless follicles looked like the electricity-sensing structures on sharks and found that one Guiana dolphin responded to electrical signals. They wondered whether other toothed cetaceans, including bottlenose dolphins, could also sense electricity. For the new study, the researchers trained two bottlenose dolphins to rest their jaws, or rostrums, on a platform and swim away anytime they experienced a sensory cue like a sound or a flash of light. If they didn’t detect one of these signals, the dolphins were to stay put. “It’s basically the same as when we go to the doctor’s and do a hearing test — we have to press a button as soon as we hear a sound,” said Tim Hüttner, a biologist at the Nuremberg Zoo in Germany and a study co-author. Once trained, the dolphins also received electrical signals. “The dolphins responded correctly on the first trial,” Dr. Hüttner said. The animals were able to transfer what they had learned, revealing that they could also detect electric fields. Further study showed that the dolphins’ sensitivity to electricity was similar to that of the platypus, which is thought to use its electrical sense for foraging. © 2023 The New York Times Company

Related chapters from BN: Chapter 9: Hearing, Balance, Taste, and Smell; Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 6: Hearing, Balance, Taste, and Smell; Chapter 5: The Sensorimotor System
Link ID: 29037 - Posted: 12.09.2023

By Paula Span A year ago, the Food and Drug Administration announced new regulations allowing the sale of over-the-counter hearing aids and setting standards for their safety and effectiveness. That step — which was supposed to take three years but required five — portended cheaper, high-quality hearing aids that people with mild to moderate hearing loss could buy online or at local pharmacies and big stores. So how’s it going? It’s a mixed picture. Manufacturers and retailers have become serious about making hearing aids more accessible and affordable. Yet the O.T.C. market remains confusing, if not downright chaotic, for the mostly older consumers the new regulations were intended to help. The past year also brought renewed focus on the importance of treating hearing loss, which affects two-thirds of people over age 70. Researchers at Johns Hopkins University published the first randomized clinical trial showing that hearing aids could help reduce the pace of cognitive decline. Some background: In 2020, the influential Lancet Commission on Dementia Prevention, Intervention and Care identified hearing loss as the greatest potentially modifiable risk factor for dementia. Previous studies had demonstrated a link between hearing loss and cognitive decline, said Dr. Frank Lin, an otolaryngologist and epidemiologist at Johns Hopkins and lead author of the new research. “What remained unanswered was, If we treat hearing loss, does it actually reduce cognitive loss?” he said. The ACHIEVE study (for Aging and Cognitive Health Evaluation in Elders) showed that, at least for a particular group of older adults, it could. Of nearly 1,000 people ages 70 to 84 with untreated mild to moderate hearing loss, half received hearing assessments from audiologists, were fitted with midpriced hearing aids and were counseled on how to use them for several months. The control group participated in a health education program. Over three years, the study found that hearing-aid use had scant effect on healthy volunteers at low risk of cognitive loss. But among participants who were older and less affluent, hearing aids reduced the rate of cognitive decline by 48 percent, compared with the control group, a difference the researchers deemed “clinically meaningful.” © 2023 The New York Times Company

Related chapters from BN: Chapter 9: Hearing, Balance, Taste, and Smell; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 6: Hearing, Balance, Taste, and Smell; Chapter 13: Memory and Learning
Link ID: 28979 - Posted: 11.01.2023

By Claudia López Lloreda In what seems like something out of a sci-fi movie, scientists have plucked the famous Pink Floyd song “Another Brick in the Wall” from individuals’ brains. Using electrodes, computer models and brain scans, researchers previously have been able to decode and reconstruct individual words and entire thoughts from people’s brain activity (SN: 11/15/22; SN: 5/1/23). The new study, published August 15 in PLOS Biology, adds music into the mix, showing that songs can also be decoded from brain activity and revealing how different brain areas pick up an array of acoustical elements. The finding could eventually help improve devices that allow communication from people with paralysis or other conditions that limit one’s ability to speak. People listened to Pink Floyd’s “Another Brick in the Wall” song while having their brain activity monitored. Using that data and a computer model, researchers were able to reconstruct sounds that resemble the song. To decode the song, neuroscientist Ludovic Bellier of the University of California, Berkeley and colleagues analyzed the brain activity recorded by electrodes implanted in the brains of 29 individuals with epilepsy. While in the hospital undergoing monitoring for the disorder, the individuals listened to the 1979 rock song. People’s nerve cells, particularly those in auditory areas, responded to hearing the song, and the electrodes detected not only neural signals associated with words but also rhythm, harmony and other musical aspects, the team found. With that information, the researchers developed a computer model to reconstruct sounds from the brain activity data, and found that they could produce sounds that resemble the song. © Society for Science & the Public 2000–2023.

Related chapters from BN: Chapter 2: Functional Neuroanatomy: The Cells and Structure of the Nervous System; Chapter 9: Hearing, Balance, Taste, and Smell
Related chapters from MM:Chapter 2: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals; Chapter 6: Hearing, Balance, Taste, and Smell
Link ID: 28876 - Posted: 08.19.2023

By Elizabeth Preston Some things need no translation. No matter what language you speak, you can probably recognize a fellow human who is cheering in triumph or swearing in anger. If you are a crocodile, you may recognize the sound of a young animal crying in distress, even if that animal is a totally different species — like, say, a human baby. That sound means you are close to a meal. In a study published Wednesday in Proceedings of the Royal Society B, researchers put speakers near crocodiles and played recordings of human, bonobo and chimpanzee infants. The crocodiles were attracted to the cries, especially shrieks that sounded more distressed. “That means that distress is something that is shared by species that are really, really distant,” said Nicolas Grimault, a bioacoustic research director at the French National Centre for Scientific Research and one of the paper’s authors. “You have some kind of emotional communication between crocodiles and humans.” These infant wails most likely drew crocodiles because they signaled an easy meal nearby, the authors say. But in some cases, the opposite may have been true: The crocs were trying to help. The animals in the study were Nile crocodiles, African predators that can reach up to 18 feet long. Understandably, the researchers kept their distance. They visited the reptiles at a Moroccan zoo and placed remote-controlled loudspeakers on the banks of outdoor ponds. The researchers played recordings of cries from those speakers while groups of up to 25 crocodiles were nearby. Some cries came from infant chimpanzees or bonobos calling to their mothers. Others were human babies, recorded either at bath time or in the doctor’s office during a vaccination. Nearly all of the recordings prompted some crocodiles to look or to move toward the speaker. When they heard the sounds of human babies getting shots, for example, almost half the crocodiles in a group responded. Dr. Grimault said the reptiles seemed most tempted by cries with a harsh quality that other studies have linked to distress in mammals. © 2023 The New York Times Company

Related chapters from BN: Chapter 9: Hearing, Balance, Taste, and Smell; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 6: Hearing, Balance, Taste, and Smell
Link ID: 28871 - Posted: 08.09.2023