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Hear my chewin': how jawbones evolved into ear bones

by Cian O'Luanaigh THE bones of your middle ear were once part of a mammalian ancestor's jaw. Now a remarkable Cretaceous fossil provides a snapshot of how this shift took place. The lower jaws of modern mammals have just one bone: the tooth-bearing dentary. Reptiles, by contrast, also sport smaller bones where the jaw meets the skull. Biologists have long postulated that as mammals evolved, the smaller, post-dentary bones shrank to form the tiny bones of the middle ear. Fossils of ancient mammals such as Morganucodon hint at this: the post-dentary bones are still attached to the dentary, and are used for both hearing and feeding. What happened next had been left to best guesses. Now Liaoconodon hui, discovered in China by Jin Meng of the American Museum of Natural History in New York, has filled the gap. "It is the first unambiguous evidence showing that transitional stage," says Meng. The 120-million-year-old mammal, about the size of a large rat, was a close relative of early mammals. Of interest is a bridge called Meckel's cartilage, which connects the small bones to the jaw (see diagram). Living mammals, including humans, have Meckel's cartilage as embryos, but it disappears as they mature. In the L. hui fossil - an adult - it is ossified and the fossil shows how it supported some of the post-dentary bones as they shifted into the ear (Nature, DOI: 10.1038/nature09921). © Copyright Reed Business Information Ltd.

Related chapters from BP6e: Chapter 9: Hearing, Vestibular Perception, Taste, and Smell; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 6: Hearing, Balance, Taste, and Smell
Link ID: 15217 - Posted: 04.14.2011

Early Birds Smelled Good

by Michael Balter About 65 million years ago, most of the dinosaurs and many other animals and plants were wiped off Earth, probably due to an asteroid hitting our planet. Researchers have long debated how and why some species survived the so-called Cretaceous-Tertiary mass extinction, marked in ancient rocks by a transition called the K-T boundary. A new study suggests that one group of survivors, the birds, may have sniffed their way across by evolving an enhanced sense of smell. Scientists had long thought that birds have a poor sense of smell. But several recent studies show that birds use smell to help them forage for food, communicate with other birds, and even orient themselves in flight. And a 2009 study of dinosaur olfaction, led by paleontologist Darla Zelenitsky of the University of Calgary in Canada, found that dinosaur lineages thought to have given rise to today's birds some 150 million years ago had a keener sense of smell than dinosaurs that went extinct without leaving feathered progeny behind. To further explore how the sense of smell might have influenced bird evolution, Zelenitsky and her colleagues looked at the olfactory abilities of 157 species of dinosaurs, extinct birds, and living birds. As in the earlier work, the team used a parameter called the olfactory ratio as a proxy for how keen a bird's sense of smell is. In the vertebrates (animals with backbones), smell is processed in the olfactory bulb, which in birds and reptiles is found in the very front of the brain. In birds, the olfactory ratio is the relative size of the bulb compared with that of the brain's cerebral hemispheres and is usually expressed as a percentage. Numerous studies in birds have shown the olfactory ratio, which ranges from less than 10% to more than 30% in a few species, to be a reliable indicator of the sense of smell. © 2010 American Association for the Advancement of Science.

Ocean Noise Could Harm Squid and Their Ilk

by Rebecca Kessler Most years, Spaniards encounter just one giant squid as long as a city bus along their northern shores—a fisherman might haul one up from the depths accidentally, or beachgoers might stumble across a carcass stranded on a beach. So it was surprising in 2001 when five squid littered the beaches over a 2-month period and in 2003 when four washed up or were found floating at sea near death in a single month. At the time of the strandings, ships offshore were exploring for oil and gas with air guns, which produce high-intensity, low-frequency sounds. Some researchers suspected that the loud noises were harming the squid, just as they are known to harm marine mammals. A new study supports that hunch, reporting massive damage to the sound-detecting structures of squid and other cephalopods that were exposed to loud noises. In recent years, scientists have gathered evidence that sonar and other humanmade noises may hurt everything from whales to crustaceans. But they didn't know whether this audio pollution could perturb cephalopods—the animal group that includes cuttlefish, squid, and octopuses—because researchers have only recently demonstrated their ability to hear. To find out, a team led by marine bioacoustician Michel André of the Technical University of Catalonia in Spain brought 87 wild cephalopods back to laboratory aquariums. For 2 hours, the researchers blared low-frequency sounds that were between 157 and 175 decibels at the animals. For comparison, a supertanker's engine noise might hit 190 decibels in the water 1 meter away from the ship. At intervals up to 96 hours after the sound barrage, the researchers killed the animals and preserved their statocysts—the sound-detecting structures behind their eyes—for microscopic analysis. For controls, the researchers killed and collected the statocysts of 100 wild cephalopods immediately after they were captured. © 2010 American Association for the Advancement of Science.

Related chapters from BP6e: Chapter 9: Hearing, Vestibular Perception, Taste, and Smell
Related chapters from MM:Chapter 6: Hearing, Balance, Taste, and Smell
Link ID: 15205 - Posted: 04.12.2011

Ear implants for the deaf with no strings attached

by Duncan Graham-Rowe COCHLEAR implants have helped thousands of deaf people around the world hear for the first time. Now a tiny microphone implanted in a person's ear will provide them with continuous hearing day and night. Existing implants can't be worn all the time because only a small part of the device is actually inside the cochlea. A fragile external unit containing the power supply, processors and microphone has to be hooked onto the ear and linked magnetically to the implant beneath the skin. "Patients can't normally wear them in their sleep, in the shower, the rain or when they swim," says Herman Jenkins, chair of otolaryngology at the University of Colorado in Aurora. "A fully implanted system would get rid of all that because you could wear it round the clock," Jenkins says. But developing an internal microphone for such a system is quite a challenge. Four years ago Cochlear, a firm based in Sydney, Australia, ran trials of a prototype implant in three patients, with mixed results, says Jan Janssen, head of Cochlear's design and development. "People clearly appreciated the ability to hear 24/7," he says. But because the microphone was actually inside the ear it would pick up not just external sounds but also a wide range of bodily noises, including the sound of eating, swallowing, the rustling of hair and the beating of the heart. So Cochlear turned to Otologics, a company in Boulder, Colorado, that was developing a fully implantable hearing aid with a new microphone that incorporates two sensors. © Copyright Reed Business Information Ltd.

Noise is what ails beaked whales

By Rachel Ehrenberg Navy sonar unquestionably disturbs beaked whales, concludes a new analysis investigating how underwater sound affects these elusive deep-divers. The results, published online March 14 in PLoS ONE, suggest that the current noise levels deemed risky for beaked whales need to be lowered. During sonar exercises at the U.S. Navy’s underwater test range in the Bahamas, beaked whales stopped their chirpy echolocations and fled the area, experiments employing a huge array of underwater microphones revealed. Other experiments that exposed tagged whales to increasing levels of sound found that at exposures of around 140 decibels, the animals stopped hunting for food and slowly swam toward the surface, heading north toward the only exit of the deepwater basin known as the Tongue of the Ocean. Current regulations rate underwater exposures of about 160 decibels as disturbing. “It seems beaked whales may be more sensitive than other species to sound,” says study leader Peter Tyack of the Woods Hole Oceanographic Institution in Massachusetts. “At the very least we may need a special rule for these whales,” he says. “If the criteria are changed they will be more protected.” Until a few different species of beaked whales started showing up in unusual mass strandings, the animals were understudied and rarely seen. Because the strandings often coincided with nearby naval sonar exercises, scientists suspected sonar was somehow driving these whales to the beach. And strange bubbles in the bodies of some of the whales suggested that sonar might trigger behavior that gave the whales the equivalent of the bends. © Society for Science & the Public 2000 - 2011

Music is all in the mind

Philip Ball A pianist plays a series of notes, and the woman echoes them on a computerized music system. The woman then goes on to play a simple improvised melody over a looped backing track. It doesn't sound like much of a musical challenge — except that the woman is paralysed after a stroke, and can make only eye, facial and slight head movements. She is making the music purely by thinking. This is a trial of a computer-music system that interacts directly with the user's brain, by picking up the tiny electrical impulses of neurons. The device, developed by composer and computer-music specialist Eduardo Miranda of the University of Plymouth, UK, working with computer scientists at the University of Essex, should eventually help people with severe physical disabilities, caused by brain or spinal-cord injuries, for example, to make music for recreational or therapeutic purposes. The findings are published online in the journal Music and Medicine1. "This is an interesting avenue, and might be very useful for patients," says Rainer Goebel, a neuroscientist at Maastricht University in the Netherlands who works on brain-computer interfacing. Evidence suggests that musical participation can be beneficial for people with neurodegenerative diseases such as dementia and Parkinson's disease. But people who have almost no muscle movement have generally been excluded from such benefits, and can enjoy music only through passive listening. © 2011 Nature Publishing Group,

Navy Sonar May Mimic Killer Whale Sounds

by John C. Cannon Sonar drives beaked whales long distances from their favorite deep-water habitats, according to the first study conducted during actual U.S. Navy exercises. The finding could explain why these whales sometimes end up in dangerously shallow water where they could strand. It also suggests that the level of sonar that the Navy considers safe may be too high. Blainville's beaked whales belong to a mysterious family of long-snouted whales that prowl kilometer-deep ocean canyons, often far from land. And yet, beaked whales often turn up stranded shortly after the intense sonar exercises the Navy uses to train sailors to detect silent enemy submarines. During one such event in 2000, six beaked whales died on beaches in the Bahamas following Navy testing. Some researchers have hypothesized that sonar noise scares whales into dangerous dive patterns, causing disorienting bends-like symptoms that could throw them off course and into unfamiliar shallow water. But solid evidence for sonar's effects on whale behavior has remained elusive, in part because these whales spend so little time at the surface that charting their behavior is difficult. Previous studies have also played back sonar recordings rather than tracking the effects of actual Navy exercises. So in the new study, animal behaviorist Peter Tyack of the Woods Hole Oceanographic Institution in Massachusetts and colleagues enlisted the Navy's help. The researchers set up at the Atlantic Undersea Test and Evaluation Center in the Bahamas, where the Navy trains sailors in sonar use. With a set of underwater microphones, they listened for the "click trains" of Blainville's beaked whales—signature sets of clicks that the animals use to home in on squid and other favorite prey in the murky depths of the sea. © 2010 American Association for the Advancement of Science.

A man lost in musical time

By Bruce Bower The Go-Go’s had a 1982 hit record with “We Got the Beat,” but a 23-year-old man named Mathieu never got their message. Researchers have identified Mathieu as the first documented case of beat deafness, a condition in which a person can’t feel music’s beat or move in time to it. Mathieu flails in a time zone of his own when bouncing up and down to a melody, unlike people who don’t dance particularly well but generally move in sync with a musical beat, according to a team led by psychologists Jessica Phillips-Silver and Isabelle Peretz, both of the University of Montreal. What’s more, Mathieu usually fails to recognize when someone else dances out of sync to a tune, the researchers report in a paper that will appear in Neuropsychologia. “We suspect that beat deafness is specific to music and is quite rare,” Phillips-Silver says. She and her colleagues plan to investigate whether Mathieu takes an offbeat approach to nonmusical activities, such as conversational turn-taking and adjusting one’s gait to that of someone else. Language lacks the periodic rhythms found in music, so it’s unlikely that Mathieu’s problem affects speech perception, remarks cognitive scientist Josh McDermott of New York University. If periodic sounds of all kinds confuse Mathieu, this problem may loom large when he confronts complex musical beats, McDermott suggests. © Society for Science & the Public 2000 - 2011

Related chapters from BP6e: Chapter 9: Hearing, Vestibular Perception, Taste, and Smell; Chapter 19: Language and Hemispheric Asymmetry
Related chapters from MM:Chapter 6: Hearing, Balance, Taste, and Smell; Chapter 15: Language and Our Divided Brain
Link ID: 15073 - Posted: 03.05.2011

Where Call Reception Fades for Pilot Whales

By SINDYA N. BHANOO Pilot whales are highly social creatures that communicate extensively with one another through tonal calls. But their ability to make calls is severely diminished when they dive deeper than about 260 feet, researchers report in The Proceedings of The Royal Society B. Until this point, as the whales dive deeper, their calls grow louder, but beyond this the calls become softer. The whales often dive nearly 3,000 feet deep in order to capture their favorite prey — a large, calorie-rich squid. “If they want to be heard by other whales at the surface, you would expect that they would increase their volume, but that is not the case,” said Frants Jensen a biologist at Aarhus University in Denmark and the study’s lead author. Dr. Jensen and his colleagues attached tags to 12 short-finned pilot whales off the Canary Islands and logged the sound, depth and orientation of the animals. Despite the impairment due to depth, the whales continued to produce tonal calls at lower volumes until they reached about 2,600 feet. The researchers believe that at such depths the lungs of the whales collapse, severely reducing their air volume and restricting their ability to generate sound. Still, the whales find their cohorts when they reach the surface. “They manage to find their social group after each dive,” Dr. Jensen said. “It’s a highly effective social system.” © 2011 The New York Times Company

Why Music Makes You Happy

By Emily Sohn People love music for much the same reason they're drawn to sex, drugs, gambling and delicious food, according to new research. When you listen to tunes that move you, the study found, your brain releases dopamine, a chemical involved in both motivation and addiction. Even just anticipating the sounds of a composition like Vivaldi's "Four Seasons" or Phish's "You Enjoy Myself" can get the feel-good chemical flowing, found the study, which was the first to make a concrete link between dopamine release and musical pleasure. The findings offer a biological explanation for why music has been such a major part of major emotional events in cultures around the world since the beginning of human history. Through music, the study also offers new insights into how the human pleasure system works. "You're following these tunes and anticipating what's going to come next and whether it's going to confirm or surprise you, and all of these little cognitive nuances are what's giving you this amazing pleasure," said Valorie Salimpoor, a neuroscientist at McGill University in Montreal. "The reinforcement or reward happens almost entirely because of dopamine." "This basically explains why music has been around for so long," she added. "The intense pleasure we get from it is actually biologically reinforcing in the brain, and now here's proof for it." © 2011 Discovery Communications, LLC.

The Neuroscience Of Music

* By Jonah Lehrer Why does music make us feel? On the one hand, music is a purely abstract art form, devoid of language or explicit ideas. The stories it tells are all subtlety and subtext. And yet, even though music says little, it still manages to touch us deep, to tickle some universal nerves. When listening to our favorite songs, our body betrays all the symptoms of emotional arousal. The pupils in our eyes dilate, our pulse and blood pressure rise, the electrical conductance of our skin is lowered, and the cerebellum, a brain region associated with bodily movement, becomes strangely active. Blood is even re-directed to the muscles in our legs. (Some speculate that this is why we begin tapping our feet.) In other words, sound stirs us at our biological roots. As Schopenhauer wrote, “It is we ourselves who are tortured by the strings.” We can now begin to understand where these feelings come from, why a mass of vibrating air hurtling through space can trigger such intense states of excitement. A brand new paper in Nature Neuroscience by a team of Montreal researchers marks an important step in revealing the precise underpinnings of “the potent pleasurable stimulus” that is music. Although the study involves plenty of fancy technology, including fMRI and ligand-based positron emission tomography (PET) scanning, the experiment itself was rather straightforward. After screening 217 individuals who responded to advertisements requesting people that experience “chills to instrumental music,” the scientists narrowed down the subject pool to ten. (These were the lucky few who most reliably got chills.) The scientists then asked the subjects to bring in their playlist of favorite songs – virtually every genre was represented, from techno to tango – and played them the music while their brain activity was monitored. © 2010 Condé Nast Digital.

Related chapters from BP6e: Chapter 9: Hearing, Vestibular Perception, Taste, and Smell; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 6: Hearing, Balance, Taste, and Smell; Chapter 11: Emotions, Aggression, and Stress
Link ID: 14907 - Posted: 01.24.2011

Study explores how blindfolded dolphins can 'see'

By SUZETTE LABOY GRASSY KEY, Fla. -- In a lagoon in the Florida Keys, trainer Emily Guarino blindfolds a male dolphin named Tanner with special latex goggles. "You ready, Tanner?" Guarino asks the young dolphin, waiting beside his companion Kibby. At a command, another trainer gets Kibby to say 'hello' by flapping his fins on the water, splashing noisily in the enclosed lagoon at the Dolphin Research Center here, which houses 22 dolphins and is one of the leaders in dolphin cognitive studies. "Can you imitate what Kibby is doing?" Guarino asks Tanner. Within seconds, Tanner is splashing "hello" - a seemingly extraordinary feat given the blindfolded dolphin appears to only be using sound to perceive and imitate the actions of his fellow dolphin. It turns out dolphins are master imitators that somehow can "see" their environment despite blindfolds. But exactly how such a dolphin can mimic another's action is a matter of ongoing scientific study. Dr. Kelly Jaakkola, director of the nonprofit marine mammal research center, said the research to better understand dolphin intelligence will surely help further their conservation. She said such study may also be helpful in better grasping the complexities of human intelligence. "It's human nature to care more about animals we perceive as intelligent. So the more we can showcase that intelligence we give people a way to connect, to care and therefore conserve," she said. Copyright 2011 Miami Herald Media Co.

Related chapters from BP6e: Chapter 9: Hearing, Vestibular Perception, Taste, and Smell; Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 6: Hearing, Balance, Taste, and Smell; Chapter 7: Vision: From Eye to Brain
Link ID: 14901 - Posted: 01.24.2011

The Neuroscience of Tone Deafness

By Kevin Mitchell What if your brain knew something but couldn’t tell you? New research suggests that this is exactly what may be behind two rather curious conditions. Most of us are familiar with people who are tune deaf – these are the people who not only cannot sing in tune but are also unaware of that fact. Individuals with severe forms of this condition, known as amusia, are unable to detect whether particular notes within a melody are out of tune or out of key. Many are also unable to recognise melodies without lyrics or to hold a tune in their heads, even if they have just heard it. These difficulties arise despite normal hearing and also a fairly normal ability to hear the difference between isolated tones. The defect lies in connecting this sensory input with some implicit knowledge of musical structure and contours. Amusia thus falls into a class of conditions known as agnosias, which are characterised by the lack of knowledge of some, often very specific, category of object. Another, equally curious, example of this class of condition is prosopagnosia – the lack of knowledge of faces. People with severe prosopagnosia may be completely unable to recognise the faces of famous people, friends, loved ones, even their own faces. As with amusia, this reflects a high-level deficit – people with prosopagnosia have normal vision and the ability to distinguish specific facial features, gender, even facial emotions. Both conditions thus seem to reflect the inability to link incoming sensory information (a person’s face or a specific note) with stored, implicit knowledge about that category (the person’s identity or a specific melody or general rules of melodic stucture). © 2011 Scientific American, a Division of Nature America, Inc.

Related chapters from BP6e: Chapter 9: Hearing, Vestibular Perception, Taste, and Smell; Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 6: Hearing, Balance, Taste, and Smell; Chapter 14: Attention and Consciousness
Link ID: 14888 - Posted: 01.21.2011

Rebooting the brain helps stop the ring of tinnitus in rats

NIH-funded researchers were able to eliminate tinnitus in a group of rats by stimulating a nerve in the neck while simultaneously playing a variety of sound tones over an extended period of time, says a study published today in the advance online publication of the journal Nature. The hallmark of tinnitus is often a persistent ringing in the ears that is annoying for some, debilitating for others, and currently incurable. Similar to pressing a reset button in the brain, this new therapy was found to help retrain the part of the brain that interprets sound so that errant neurons reverted back to their original state and the ringing disappeared. The research was conducted by scientists from the University of Texas at Dallas and MicroTransponder Inc., in Dallas. "Current treatments for tinnitus generally involve masking the sound or learning to ignore it," said James F. Battey, Jr., M.D., Ph.D., director of the National Institute on Deafness and Other Communication Disorders (NIDCD), which funded a large part of the research. "If we can find a way to turn off the noise, we’ll be able to improve life substantially for the nearly 23 million American adults who suffer from this disorder." Tinnitus is a symptom some people experience as a result of hearing loss. When sensory cells in the inner ear are damaged, such as from loud noise, the resulting hearing loss changes some of the signals sent from the ear to the brain. For reasons that are not fully understood, some people will develop tinnitus as a result. "We believe the part of the brain that processes sounds — the auditory cortex — delegates too many neurons to some frequencies, and things begin to go awry," said Michael Kilgard, Ph.D., associate professor of behavior and brain sciences at UT-Dallas, and a co-principal investigator on the study. "Because there are too many neurons processing the same frequencies, they are firing much stronger than they should be."

Is Music for Wooing, Mothering, Bonding—or Is It Just "Auditory Cheesecake"?

by Carl Zimmer When Charles Darwin listened to music, he asked himself, what is it for? Philosophers had pondered the mathematical beauty of music for thousands of years, but Darwin wondered about its connection to biology. Humans make music just as beavers build dams and peacocks show off their tail feathers, he reasoned, so music must have evolved. What drove its evolution was hard for him to divine, however. “As neither the enjoyment nor the capacity of producing musical notes are faculties of the least direct use to man in reference to his ordinary habits of life, they must be ranked among the most mysterious with which he is endowed,” Darwin wrote in 1871. Today a number of scientists are trying to solve that mystery by looking at music right where we experience it: in the brain. They are scanning the activity that music triggers in our neurons and observing how music alters our biochemistry. But far from settling on a single answer, the researchers are in a pitched debate over music. Some argue that it evolved in our ancestors because it allowed them to have more children. Others see it as merely a fortunate accident of a complex brain. In many ways music appears to be hardwired in us. Anthropologists have yet to discover a single human culture without its own form of music. Children don’t need any formal training to learn how to sing and dance. And music existed long before modern civilization. In 2008 archaeologists in Germany discovered the remains of a 35,000-year-old flute. Music, in other words, is universal, easily learned, and ancient. That’s what you would expect of an instinct that evolved in our distant ancestors. © 2010, Kalmbach Publishing Co.

Mixed messages scramble sounds in the brain

Catherine de Lange, The McGurk effect is an auditory illusion. It occurs when a video of a person speaking is given different audio, so the picture and the sounds don't match. Most people will hear a third sound - neither the original audio nor the audio they've just heard (see video above). The illusion demonstrates that we rely on both auditory and visual cues to process speech correctly. Michael Beauchamp and colleagues from the University of Texas in Houston wanted to find out exactly where, and at what point during the perception process, these two senses combine in the brain. Previous studies have pointed to a brain area called the superior temporal sulcus (STS), although some researchers disagree. Now this debate can be laid to rest. Part of the problem is that the STS region for auditory-visual integration is located at a different spot in each person, says Beauchamp. He therefore began by conducting MRI scans to determine its exact location in the brain of each subject. Next, a technique called transcranial magnetic stimulation (TMS) was applied to find out whether the STS really is responsible for the McGurk effect. TMS fires a series of short electromagnetic pulses at a target area of the brain to deactivate it, so if the STS was the key, subjects undergoing TMS to that area wouldn't perceive the illusion. © Copyright Reed Business Information Ltd.

Bats Gauge Sounds With Neural Teamwork

By SINDYA N. BHANOO One of the keys to the keen ability of bats to process sound is that the neurons in a bat’s brain work as a team to convey the importance of certain signals — like an anger call or a distress call — while diminishing the effect of less-important sounds, researchers at the Georgetown University Medical Center reported this past weekend in San Diego at the annual meeting of the Society for Neuroscience. “It’s like a basketball team,” said Bridget Queenan, a neuroscientist involved in the study. “There are neurons in the brain with these roles — like five guys on the court.” In different instances, depending on the particular signal that urgently needs to be processed, the neurons act in different ways. For example, it could be that “one neuron processes the sound, another ‘shushes’ nearby neurons, and another helps boost the first neuron’s activity,” Ms. Queenan said. She and her colleagues studied the bats by inserting electrodes into their brains and recording their neural activity after a series of tones and calls. They used this to identify how individual neurons responded to calls in various instances, like when it was noisy or quiet. “So now we start to see a little a bit how these players are working together in a specific context,” she said. “It’s as if we get snapshots of a game at different points of action.” Copyright 2010 The New York Times Company

Whale mass strandings linked to hearing loss

Michael Marshall, In "one of the biggest mass deaths of cetaceans in Irish history" at least 33 whales have beached themselves on the north-west coast of County Donegal. They were found on Rutland Island near Burtonport on Saturday. It's thought they were the same group spotted in the Outer Hebrides at the end of October. The whales' deaths come just after the latest research into cetacean strandings, which suggests that stranded whales and dolphins often suffer from hearing loss. The finding is the latest salvo in the long-running controversy over whether undersea noise pollution is harming whales. David Mann of the University of South Florida and colleagues looked at eight species of cetacean, all of which had either stranded themselves or become entangled in fishing gear. 4 out of 7 of the bottlenose dolphins they looked at, and 5 out of 14 rough-toothed dolphins, had either severe or profound hearing loss, as did one short-finned pilot whale. They also looked at 7 Risso's dolphins, 2 pygmy killer whales, 1 Atlantic spotted dolphin, 1 spinner dolphin, and 1 Gervais' beaked whale. None of them had any hearing problems, so it seems hearing loss is far from the only possible cause for strandings. In total, 9 of the 34 animals had hearing problems (PLoS ONE, DOI: 10.1371/journal.pone.0013824). © Copyright Reed Business Information Ltd.

Hearing the Music, Honing the Mind

By The Editors Nearly 20 years ago a small study advanced the notion that listening to Mozart’s Sonata for Two Pianos in D Major could boost mental functioning. It was not long before trademarked “Mozart effect” products appealed to neurotic parents aiming to put toddlers on the fast track to the Ivy League. Georgia’s governor even proposed giving every newborn there a classical CD or cassette. The evidence for Mozart therapy turned out to be flimsy, perhaps nonexistent, although the original study never claimed anything more than a temporary and limited effect. In recent years, however, neuroscientists have examined the benefits of a concerted effort to study and practice music, as opposed to playing a Mozart CD or a computer-based “brain fitness” game once in a while. Advanced monitoring techniques have enabled scientists to see what happens inside your head when you listen to your mother and actually practice the violin for an hour every afternoon. And they have found that music lessons can produce profound and lasting changes that enhance the general ability to learn. These results should disabuse public officials of the idea that music classes are a mere frill, ripe for discarding in the budget crises that constantly beset public schools. Studies have shown that assiduous instrument training from an early age can help the brain to process sounds better, making it easier to stay focused when absorbing other subjects, from literature to tensor calculus. The musically adept are better able to concentrate on a biology lesson despite the racket in the classroom or, a few years later, to finish a call with a client when a colleague in the next cubicle starts screaming at an underling. They can attend to several things at once in the mental scratch pad called working memory, an essential skill in this era of multitasking. © 2010 Scientific American

"Ringing in the Ears" Actually Goes Much Deeper Than That

by Carl Zimmer In some of the world’s oldest medical texts—papyrus scrolls from ancient Egypt, clay tablets from Assyria—people complain about noise in their ears. Some of them call it a buzzing. Others describe it as whispering or even singing. Today we call such conditions tinnitus. In the distant past, doctors offered all sorts of strange cures for it. The Assyrians poured rose extract into the ear through a bronze tube. The Roman writer Pliny the Elder suggested that earthworms boiled in goose grease be put in the ear. Medieval Welsh physicians in the town of Myddfai recommended that their patients take a freshly baked loaf of bread ($) out of the oven, cut it in two, “and apply to both ears as hot as can be borne, bind and thus produce perspiration, and by the help of god you will be cured.” Early physicians based these prescriptions on what they believed tinnitus to be. Some were convinced it was caused by wind that got trapped inside the ear and swirled around endlessly, so they tried to liberate the wind by drilling a hole into the bones around the ear or using a silver tube to suck air out of the ear canal. The treatments didn’t work, but they did have an internal logic. Today tinnitus continues to resist medicine’s best efforts, despite being one of the more common medical disorders. Surveys show that between 5 and 15 percent of people say they have heard some kind of phantom noise for six months or more; some 1 to 3 percent say tinnitus lowers their quality of life. Tinnitus can force people to withdraw from their social life, make them depressed, and give them insomnia. © 2010, Kalmbach Publishing Co.

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