Drug may stop migraines before headache starts

When taken at the first signs of a migraine, before headache pain begins, a drug called ubrogepant may be effective in helping people with migraine go about their daily lives with little or no symptoms, according to a new study published in the August 28, 2024, online issue of Neurology®, the medical journal of the American Academy of Neurology. The study focused on people with migraine who could tell when an attack was about to happen, due to early symptoms such as sensitivity to light and sound, fatigue, neck pain or stiffness, or dizziness.

Ubrogepant is a calcitonin gene-related peptide receptor antagonist, or CGRP inhibitor. CGRP is a protein that plays a key role in the migraine process.

"Migraine is one of the most prevalent diseases worldwide, yet so many people who suffer from this condition do not receive treatment or report that they are not satisfied with their treatment," said study author Richard B. Lipton, MD, of Albert Einstein College of Medicine in Bronx, New York, and Fellow of the American Academy of Neurology. "Improving care at the first signs of migraine, even before headache pain begins, can be a key to improved outcomes. Our findings are encouraging, suggesting that ubrogepant may help people with migraine function normally and go about their day."

The study involved 518 participants who had migraine for at least one year and two to eight migraine attacks per month in the three months before the study. All of the participants regularly experienced signs that a migraine would be starting within the next few hours. Participants were asked to treat two attacks during a two-month period.

Researchers divided participants into two groups. The first group received a placebo for their first set of pre-headache symptoms of migraine, followed by taking 100 milligrams (mg) of ubrogepant for their second instance of symptoms. The second group took ubrogepant for the first instance and placebo for the second instance.

Participants evaluated limitations on their activity in their diary using a scale ranging from zero to five, with 0 meaning "not at all limited -- I could do everything"; 1, "a little limited"; 2, "somewhat limited"; 3, "very limited"; or 4, "extremely limited."

Twenty-four hours after taking the drug or a placebo, 65% of people who took ubrogepant reported themselves as "not at all limited -- I could do everything," or "a little limited," compared to 48% of those who took the placebo.

Researchers found that as early as two hours post-medication, people who took the drug were 73% more likely to report that they had "no disability, able to function normally," than those who took the placebo.

"Based on our findings, treatment with ubrogepant may allow people with migraine who experience early warning signs before a migraine occurs to quickly treat migraine attacks in their earliest stages and go about their daily lives with little discomfort and disruption," said Lipton. "This could lead to an improved quality of life for those living with migraine."

Lipton noted that participants showed that based on their headache warning symptoms, they could reliably predict impending migraine headaches. These findings apply only to those with reliable warning symptoms.

A limitation of the study was that participants recorded their symptoms and medication use in electronic diaries, so it is possible some people may not have recorded all information accurately.

Read more at Science Daily

Measuring Martian winds with sound

Mars has a notoriously inhospitable environment, with temperatures that fluctuate dramatically over the course of a Martian day and average minus 80 degrees Fahrenheit. Its surface is mostly covered in red dust, with terrain typified by craters, canyons, and volcanoes. And its atmosphere is extremely thin, comprising only about 1% of the density of Earth's.

Needless to say, measuring wind speeds on the red planet is challenging.

Martian landers have been able capture measurements -- some gauging the cooling rate of heated materials when winds blow over them, others using cameras to image "tell-tales" that blow in the wind.

Both anemometric methods have yielded valuable insight into the planet's climate and atmosphere.

But there's still room for improvement in the astronomical toolshed, especially as plans to send astronauts to Mars unfold in the coming years.

In JASA, published on behalf of the Acoustical Society of America by AIP Publishing, researchers from Canada and the U.S. demonstrated a novel sonic anemometric system featuring a pair of narrowband piezoelectric transducers to measure the travel time of sound pulses through Martian air.

The study accounted for variables including transducer diffraction effects and wind direction.

"By measuring sound travel time differences both forward and backward, we can accurately measure wind in three dimensions," said author Robert White.

"The two major advantages of this method are that it's fast and it works well at low speeds."

The researchers hope to be able to measure up to 100 wind speeds per second and at speeds as low as 1 cm/s, a remarkable contrast to previous methods that could register only about 1 wind speed per second and struggled to track speeds below 50 cm/s.

"By measuring quickly and accurately, we hope to be able to measure not only mean winds, but also turbulence and fluctuating winds," said White.

"This is important for understanding atmospheric variables that could be problematic for small vehicles such as the Ingenuity helicopter that flew on Mars recently."

The researchers characterized ultrasonic transducers and sensors over a wide range of temperatures and a narrow range of pressures in carbon dioxide, the primary atmospheric gas on Mars.

With their selections, they showed only nominal error rates would result from temperature and pressure changes.

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Baleen whales evolved a unique larynx to communicate but cannot escape human noise

Baleen whales are the largest animals to have ever roamed our planet and as top predators play a vital role in marine ecosystems. To communicate across vast distances and find each other, baleen whales depend critically on the production of sounds that travels far in murky and dark oceans.

However, since whale songs were first discovered more than 50 years ago, it remained unknown how baleen whales produce their complex vocalizations -- until now.

A new study in the journal Nature reports that baleen whales evolved unique structures in their larynx that enable their low-frequency vocalizations, but also limit their communication range.

The study was led by voice scientists Professor Coen Elemans, at the Department of Biology, University of Southern Denmark and Professor Tecumseh Fitch at the Department of Behavioral and Cognitive Biology, University of Vienna in Austria.

"The toothed and baleen whales evolved from land mammals that had a larynx serving two functions: protecting the airways and sound production. However, their transition to aquatic life placed new and strict demands on the larynx to prevent choking underwater," says Tecumseh Fitch.

The study shows that baleen whales nevertheless can still produce sound with their larynx, but they have evolved novel structures to do so, that only exists in baleen whales. First, the tiny cartilages in the human larynx -- called the arytenoids -- that change the position of our vocal folds, have changed dramatically in whales.

"The arytenoids changed into large, long cylinders fused at the base to form a large U-shaped rigid structure that extends nearly the full length of the larynx," Elemans says.

"This is probably to keep a rigid open airway when they have to move huge amounts of air in and out during explosive surface breathing," states Fitch.

"We found that this U-shaped structure pushes against a big fatty cushion on the inside of the larynx. When the whales push air from their lungs past this cushion, it starts to vibrate and this generates very low frequency underwater sounds," says Elemans.

Trying to work on the biology and particularly physiology of whales is very challenging.

"Even though humans hunted whales close to the brink of extinction, they made very little effort in trying to learn about their physiology," says Magnus Wahlberg, whale expert at University of Southern Denmark and co-author on the study.

"Strandings are unique and rare opportunities to learn about these amazing animals, but even then, it is very hard to study physiology, because the tissue decays so fast. Whales are known to explode on the beach," adds Wahlberg.

Thanks to Danish and Scottish Marine Mammal Stranding Networks, the researchers could quickly extract the larynx of a sei, minke and humpback whale for close investigation in the lab.

"Our experiments showed for the first time how the whales make their very low frequency vocalizations," says Elemans.

To understand how muscle activity could change the calls, the researchers built a computational model of the entire whale larynx.

"Our model includes accurate 3D shapes of the larynx and its muscles, which made it possible to simulate, for example, how the frequency is controlled through muscle modulation," say Qian Xue and Xudong Zheng, professors at the Mechanical Engineering Department at Rochester Institute of Technology, USA, co-authors on the study.

"Our model accurately predicted the results of our experiments, but we could also calculate acoustic features we could not measure in the lab, such as the frequency range," says Weili Jiang, postdoc at Rochester Institute of Technology, USA, co-author on the study.

The models predicted the natural vocalizations of the whales very well.

However, these newly discovered anatomical features that allowed whales to successfully communicate in the vast oceans also poses unsurmountable physiological limits for many baleen whales.

Combining experiments and models, the researchers provide the first evidence that baleen whales are physiologically incapable of escaping anthropogenic noise, because it masks their voices, and thus limits their communication range.

"Regrettably, the frequency range and maximum communication depth of 100 meters we predict, overlaps completely with the dominant frequency range and depth of human-made noise caused by shipping traffic," Elemans says.

"The first acoustic recordings of humpback whale song by Roger and Katy Payne in 1970 resonated with humanity profoundly, started the flourishing field of marine bioacoustics, and sparked global interest in marine conservation efforts." says Coen Elemans.

"These recordings were so politically important then that they are aboard the Voyager space missions," he continues.

The Payne's made people aware how quiet the seas were before humans started the widespread use of propeller ships and continuously running shipboard generators. Those were the seas whales evolved in.

Read more at Science Daily

Physicists capture the first sounds of heat 'sloshing' in a superfluid

In most materials, heat prefers to scatter. If left alone, a hotspot will gradually fade as it warms its surroundings. But in rare states of matter, heat can behave as a wave, moving back and forth somewhat like a sound wave that bounces from one end of a room to the other. In fact, this wave-like heat is what physicists call "second sound."

Signs of second sound have been observed in only a handful of materials. Now MIT physicists have captured direct images of second sound for the first time.

The new images reveal how heat can move like a wave, and "slosh" back and forth, even as a material's physical matter may move in an entirely different way. The images capture the pure movement of heat, independent of a material's particles.

"It's as if you had a tank of water and made one half nearly boiling," Assistant Professor Richard Fletcher offers as analogy. "If you then watched, the water itself might look totally calm, but suddenly the other side is hot, and then the other side is hot, and the heat goes back and forth, while the water looks totally still."

Led by Martin Zwierlein, the Thomas A Frank Professor of Physics, the team visualized second sound in a superfluid -- a special state of matter that is created when a cloud of atoms is cooled to extremely low temperatures, at which point the atoms begin to flow like a completely friction-free fluid. In this superfluid state, theorists have predicted that heat should also flow like a wave, though scientists had not been able to directly observe the phenomenon until now.

The new results, reported in the journal Science, will help physicists get a more complete picture of how heat moves through superfluids and other related materials, including superconductors and neutron stars.

"There are strong connections between our puff of gas, which is a million times thinner than air, and the behavior of electrons in high-temperature superconductors, and even neutrons in ultradense neutron stars," Zwierlein says. "Now we can probe pristinely the temperature response of our system, which teaches us about things that are very difficult to understand or even reach."

Zwierlein and Fletcher's co-authors on the study are first author and former physics graduate student Zhenjie Yan and former physics graduate students Parth Patel and Biswaroop Mikherjee, along with Chris Vale at Swinburne University of Technology in Melbourne, Australia. The MIT researchers are part of the MIT-Harvard Center for Ultracold Atoms (CUA).

Super sound

When clouds of atoms are brought down to temperatures close to absolute zero, they can transition into rare states of matter. Zwierlein's group at MIT is exploring the exotic phenomena that emerge among ultracold atoms, and specifically fermions -- particles, such as electrons, that normally avoid each other.

Under certain conditions, however, fermions can be made to strongly interact and pair up. In this coupled state, fermions can flow in unconventional ways. For their latest experiments, the team employs fermionic lithium-6 atoms, which are trapped and cooled to nanokelvin temperatures.

In 1938, the physicist László Tisza proposed a two-fluid model for superfluidity -- that a superfluid is actually a mixture of some normal, viscous fluid and a friction-free superfluid. This mixture of two fluids should allow for two types of sound, ordinary density waves and peculiar temperature waves, which physicist Lev Landau later named "second sound."

Since a fluid transitions into a superfluid at a certain critical, ultracold temperature, the MIT team reasoned that the two types of fluid should also transport heat differently: In normal fluids, heat should dissipate as usual, whereas in a superfluid, it could move as a wave, similarly to sound.

"Second sound is the hallmark of superfluidity, but in ultracold gases so far you could only see it in this faint reflection of the density ripples that go along with it," Zwierlein says. "The character of the heat wave could not be proven before."

Tuning in

Zwierlein and his team sought to isolate and observe second sound, the wave-like movement of heat, independent of the physical motion of fermions in their superfluid. They did so by developing a new method of thermography -- a heat-mapping technique. In conventional materials one would use infrared sensors to image heat sources.

But at ultracold temperatures, gases do not give off infrared radiation. Instead, the team developed a method to use radio frequencyto "see" how heat moves through the superfluid. They found that the lithium-6 fermions resonate at different radio frequencies depending on their temperature: When the cloud is at warmer temperatures, and carries more normal liquid, it resonates at a higher frequency. Regions in the cloud that are colder resonate at a lower frequency.

The researchers applied the higher resonant radio frequency, which prompted any normal, "hot" fermions in the liquid to ring in response. The researchers then were able to zero in on the resonating fermions and track them over time to create "movies" that revealed heat's pure motion -- a sloshing back and forth, similar to waves of sound.

"For the first time, we can take pictures of this substance as we cool it through the critical temperature of superfluidity, and directly see how it transitions from being a normal fluid, where heat equilibrates boringly, to a superfluid where heat sloshes back and forth," Zwierlein says.

The experiments mark the first time that scientists have been able to directly image second sound, and the pure motion of heat in a superfluid quantum gas. The researchers plan to extend their work to more precisely map heat's behavior in other ultracold gases. Then, they say their findings can be scaled up to predict how heat flows in other strongly interacting materials, such as in high-temperature superconductors, and in neutron stars.

"Now we will be able to measure precisely the thermal conductivity in these systems, and hope to understand and design better systems," Zwierlein concludes.

Read more at Science Daily

Vision via sound for the blind

Australian researchers have developed cutting-edge technology known as "acoustic touch" that helps people 'see' using sound. The technology has the potential to transform the lives of those who are blind or have low vision.

Around 39 million people worldwide are blind, according to the World Health Organisation, and an additional 246 million people live with low vision, impacting their ability to participate in everyday life activities.

The next generation smart glasses, which translate visual information into distinct sound icons, were developed by researchers from the University of Technology Sydney and the University of Sydney, together with Sydney start-up ARIA Research.

"Smart glasses typically use computer vision and other sensory information to translate the wearer's surrounding into computer-synthesized speech," said Distinguished Professor Chin-Teng Lin, a global leader in brain-computer interface research from the University of Technology Sydney.

"However, acoustic touch technology sonifies objects, creating unique sound representations as they enter the device's field of view. For example, the sound of rustling leaves might signify a plant, or a buzzing sound might represent a mobile phone," he said.

A study into the efficacy and usability of acoustic touch technology to assist people who are blind, led by Dr Howe Zhu from the University of Technology Sydney, has just been published in the journal PLOS ONE.

The researchers tested the device with 14 participants; seven individuals with blindness or low vision and seven blindfolded sighted individuals who served as a control group.

They found that the wearable device, equipped with acoustic touch technology, significantly enhanced the ability of blind or low-vision individuals to recognise and reach for objects, without causing too much mental effort.

"The auditory feedback empowers users to identify and reach for objects with remarkable accuracy," said Dr Zhu. "Our findings indicate that acoustic touch has the potential to offer a wearable and effective method of sensory augmentation for the visually impaired community."

The research underscores the importance of developing assistive technology in overcoming the challenges such as locating specific household items and personal belongings.

By addressing these day-to-day challenges, the acoustic touch technology opens new doors for individuals who are blind or have low vision, enhancing their independence and quality of life.

Read more at Science Daily

Physicists demonstrate how sound can be transmitted through vacuum

A classic movie was once promoted with the punchline: "In space, no one can hear you scream." Physicists Zhuoran Geng and Ilari Maasilta from the Nanoscience Center at the University of Jyväskylä, Finland, have demonstrated, on the contrary, that in certain situations sound can be transmitted strongly across a vacuum region!

In a recent publication they show that in some cases a sound wave can jump or "tunnel" fully across a vacuum gap between two solids if the materials in question are piezoelectric. In such materials, vibrations (sound waves) produce an electrical response, as well, and since an electric field can exist in vacuum, it can transmit the sound waves across. The requirement is that the size of the gap is smaller than the wavelength of the sound wave. This effect works not only in audio range of frequencies (Hz-kHz), but also in ultrasound (MHz) and hypersound (GHz) frequencies, as long as the vacuum gap is made smaller as the frequencies increase.

- In most cases the effect is small, but we also found situations, where the full energy of the wave jumps across the vacuum with 100 % efficiency, without any reflections. As such, the phenomenon could find applications in microelectromechanical components (MEMS, smartphone technology) and in the control of heat, says professor Ilari Maasilta from the Nanoscience Center at the University of Jyväskylä.

Read more at Science Daily

Sound recording made of dust devils (tiny tornadoes of dust, grit) on Mars

When the rover Perseverance landed on Mars, it was equipped with the first working microphone on the planet's surface. Scientists have used it to make the first-ever audio recording of an extraterrestrial whirlwind.

The study was published in Nature Communications by planetary scientist Naomi Murdoch and a team of researchers at the National Higher French Institute of Aeronautics and Space and NASA. Roger Wiens, professor of earth, atmospheric and planetary sciences in Purdue University's College of Science, leads the instrument team that made the discovery. He is the principal investigator of Perseverance's SuperCam, a suite of tools that comprise the rover's "head" that includes advanced remote-sensing instruments with a wide range of spectrometers, cameras and the microphone.

"We can learn a lot more using sound than we can with some of the other tools," Wiens said. "They take readings at regular intervals. The microphone lets us sample, not quite at the speed of sound, but nearly 100,000 times a second. It helps us get a stronger sense of what Mars is like."

The microphone is not on continuously; it records for about three minutes every couple of days. Getting the whirlwind recording, Wiens said, was lucky, though not necessarily unexpected. In the Jezero Crater, where Perseverance landed, the team has observed evidence of nearly 100 dust devils -- tiny tornadoes of dust and grit -- since the rover's landing. This is the first time the microphone was on when one passed over the rover.

The sound recording of the dust devil, taken together with air pressure readings and time-lapse photography, help scientists understand the Martian atmosphere and weather.

"We could watch the pressure drop, listen to the wind, then have a little bit of silence that is the eye of the tiny storm, and then hear the wind again and watch the pressure rise," Wiens said. It all happened in a few seconds. "The wind is fast -- about 25 miles per hour, but about what you would see in a dust devil on Earth. The difference is that the air pressure on Mars is so much lower that the winds, while just as fast, push with about 1% of the pressure the same speed of wind would have back on Earth. It's not a powerful wind, but clearly enough to loft particles of grit into the air to make a dust devil."

The information indicates that future astronauts will not have to worry about gale-force winds blowing down antennas or habitats -- so future Mark Watneys won't be left behind -- but the wind may have some benefits. The breezes blowing grit off the solar panels of other rovers -- especially Opportunity and Spirit -- may be what helped them last so much longer.

"Those rover teams would see a slow decline in power over a number of days to weeks, then a jump. That was when wind cleared off the solar panels," Wiens said.

The lack of such wind and dust devils in the Elysium Planitia where the InSIght mission landed may help explain why that mission is winding down.

Read more at Science Daily

Wireless earphones work as inexpensive hearing aids

Some commercial earbuds can perform as well as hearing aids. The result, presented November 15 in the journal iScience, could help a large proportion of people with hearing loss access more affordable sound amplification devices.

Hearing loss has broad health impacts, but professional hearing aids are expensive and require multiple visits to otolaryngologists and audiologists for tuning. These factors lead to major barriers for many to access professional hearing aids. One estimate suggests nearly 75% of people with hearing loss in the United States do not use hearing aids.

"There's also a social stigma associated with hearing aids," says Yen-fu Cheng, the study's corresponding author and an otolaryngologist at Taipei Veterans General Hospital. "Many patients are reluctant to wear them because they don't want to appear old. So, we started exploring if there're are more accessible alternatives."

Apple came out with a feature called "Live Listen" in 2016 that allows people to use its wireless earphones, AirPods, and iPhone for sound amplification. The feature makes AirPods functionally similar to a personal sound amplification product, which is designed for people with normal hearing for certain occasions like birdwatching.

Cheng and his team wanted to investigate whether AirPods, which are widely available devices, can serve as alternative hearing aids. The team compared Airpods 2 and AirPods Pro -- the model with a noise canceling feature -- with a type of premium hearing aids and a basic pair of hearing aids. The premium hearing aids cost $10,000, and the basic type cost $1,500. Both models of AirPods are significantly cheaper than hearing aids, with AirPods 2 costing $129 and AirPods Pro costing $249. Notably, AirPods Pro met four out of five technology standards for hearing aids.

The team tested the four devices with 21 participants with mild to moderate hearing loss. The researchers read a short sentence, such as "the electricity bills went up recently," to participants, who were asked to repeat their words verbatim wearing the devices. They found AirPods Pro performed similarly well compared with basic hearing aids in a quiet environment and is slightly inferior to premium hearing aids. AirPods 2, while having the lowest performance among the four, helped participants hear more clearly compared with wearing no hearing aids.

In a noisy environment, AirPods Pro showed comparable performance to premium hearing aids when the noises came from the lateral direction of the participant. But when the noises came from the front of the participants, both AirPods models failed to help participants hear better.

"Two reasons may account for the difference between the two scenarios," says Ying-Hui Lai, the study's co-author and a bioengineer at National Yang Ming Chiao Tung University in Taipei. "It may relate to the trajectories soundwaves travel with, as well as the advanced signal processing algorithm by premium hearing aids. This finding will hopefully inspire engineers to design hearing aids and personal sound amplification products that are more sensitive in certain directions." He adds that AirPods Pro appears to perform better than AirPods 2, likely because of its noise-canceling feature.

"Globally, the wireless earphone market is growing rapidly. Some companies are interested in exploring the possibility of designing earbuds with sound amplification features. Our study proves that the idea is plausible," Lai says.

As a clinician, Cheng says persuading patients to use hearing aids is often challenging. "These wireless earbuds are of course not perfect, but they would be a good starting point for many patients who don't have access to professional hearing aids. They will see an increase in quality of life even with these earbuds." Cheng says.

Read more at Science Daily

During sleep the brain's reaction to sound remains strong, but one critical feature of conscious attention disappears

A new discovery from Tel Aviv University may provide a key to a great scientific enigma: How does the awake brain transform sensory input into a conscious experience? The groundbreaking study relied on data collected from electrodes implanted, for medical purposes, deep in the human brain. The information was utilized to examine differences between the response of the cerebral cortex to sounds in sleep vs. wakefulness, at a resolution of single neurons.

The researchers were surprised to discover that the brain's response to sound remains powerful during sleep in all parameters but one: the level of alpha-beta waves associated with attention to the auditory input and related expectations. This means that during sleep, the brain analyzes the auditory input but is unable to focus on the sound or identify it, and therefore no conscious awareness ensues.

The study was led by Dr. Hanna Hayat and with major contribution from Dr. Amit Marmelshtein, at the lab of Prof. Yuval Nir from the School of Medicine, the Sagol School of Neuroscience, and the Department of Biomedical Engineering, and co-supervised by Prof. Itzhak Fried from the UCLA Medical Center. Other participants included: Dr. Aaron Krom and Dr. Yaniv Sela from Prof. Nir's group, and Dr. Ido Strauss and Dr. Firas Fahoum from the Tel Aviv Sourasky Medical Center (Ichilov). The paper was published in the journal Nature Neuroscience.

Prof. Nir: "This study is unique in that it builds upon rare data from electrodes implanted deep inside the human brain, enabling high-resolution monitoring, down to the level of individual neurons, of the brain's electrical activity. For understandable reasons, electrodes cannot be implanted in the brain of living humans just for the sake of scientific research. But in this study, we were able to utilize a special medical procedure in which electrodes were implanted in the brains of epilepsy patients, monitoring activity in different parts of their brain for purposes of diagnosis and treatment. The patients volunteered to help examine the brain's response to auditory stimulation in wakefulness vs. sleep."

The researchers placed speakers emitting various sounds at the patients' bedside and compared data from the implanted electrodes -- neural activity and electrical waves in different areas of the brain -- during wakefulness vs. various stages of sleep. Altogether, the team collected data from over 700 neurons, about 50 neurons in each patient, over the course of 8 years.

Dr. Hayat: "After sounds are received in the ear, the signals are relayed from one station to the next within the brain. Until recently it was believed that during sleep these signals decay rapidly once they reach the cerebral cortex. But looking at the data from the electrodes, we were surprised to discover that the brain's response during sleep was much stronger and richer than we had expected. Moreover, this powerful response spread to many regions of the cerebral cortex. The strength of brain response during sleep was similar to the response observed during wakefulness, in all but one specific feature, where a dramatic difference was recorded: the level of activity of alpha-beta waves."

The researchers explain that alpha-beta waves (10-30Hz) are linked to processes of attention and expectation that are controlled by feedback from higher regions in the brain. As signals travel 'bottom-up' from the sensory organs to higher regions, a 'top-down' motion also occurs: the higher regions, relying on prior information that had accumulated in the brain, act as a guide, sending down signals to instruct the sensory regions as to which input to focus on, which should be ignored, etc. Thus, for example, when a certain sound is received in the ear, the higher regions can tell whether it is new or familiar, and whether it deserves attention or not. This kind of brain activity is manifested in the suppression of alpha-beta waves, and indeed, previous studies have shown a high level of these waves in states of rest and anesthesia. According to the current study, the strength of alpha-beta waves is the main difference between the brain's response to auditory inputs in states of wakefulness vs. sleep.

Prof Nir summarizes: "Our findings have wide implications beyond this specific experiment. First, they provide an important key to an ancient, fascinating enigma: What is the secret of consciousness? What is the 'X-factor', the brain activity that is unique to consciousness, allowing us to be aware of things happening around us when we are awake, and disappearing when we sleep? In this study we discovered a new lead, and in future research we intend to further explore the mechanisms responsible for this difference.

Read more at Science Daily

How sound reduces pain in mice

An international team of scientists has identified the neural mechanisms through which sound blunts pain in mice. The findings, which could inform development of safer methods to treat pain, were published in Science. The study was led by researchers at the National Institute of Dental and Craniofacial Research (NIDCR); the University of Science and Technology of China, Hefei; and Anhui Medical University, Hefei, China. NIDCR is part of the National Institutes of Health.

"We need more effective methods of managing acute and chronic pain, and that starts with gaining a better understanding of the basic neural processes that regulate pain," said NIDCR Director Rena D'Souza, D.D.S., Ph.D. "By uncovering the circuitry that mediates the pain-reducing effects of sound in mice, this study adds critical knowledge that could ultimately inform new approaches for pain therapy."

Dating back to 1960, studies in humans have shown that music and other kinds of sound can help alleviate acute and chronic pain, including pain from dental and medical surgery, labor and delivery, and cancer. However, how the brain produces this pain reduction, or analgesia, was less clear.

"Human brain imaging studies have implicated certain areas of the brain in music-induced analgesia, but these are only associations," said co-senior author Yuanyuan (Kevin) Liu, Ph.D., a Stadtman tenure-track investigator at NIDCR. "In animals, we can more fully explore and manipulate the circuitry to identify the neural substrates involved."

The researchers first exposed mice with inflamed paws to three types of sound: a pleasant piece of classical music, an unpleasant rearrangement of the same piece, and white noise. Surprisingly, all three types of sound, when played at a low intensity relative to background noise (about the level of a whisper) reduced pain sensitivity in the mice. Higher intensities of the same sounds had no effect on animals' pain responses.

"We were really surprised that the intensity of sound, and not the category or perceived pleasantness of sound would matter," Liu said.

To explore the brain circuitry underlying this effect, the researchers used non-infectious viruses coupled with fluorescent proteins to trace connections between brain regions. They identified a route from the auditory cortex, which receives and processes information about sound, to the thalamus, which acts as a relay station for sensory signals, including pain, from the body. In freely moving mice, low-intensity white noise reduced the activity of neurons at the receiving end of the pathway in the thalamus.

In the absence of sound, suppressing the pathway with light- and small molecule-based techniques mimicked the pain-blunting effects of low-intensity noise, while turning on the pathway restored animals' sensitivity to pain.

Liu said it is unclear if similar brain processes are involved in humans, or whether other aspects of sound, such as its perceived harmony or pleasantness, are important for human pain relief.

"We don't know if human music means anything to rodents, but it has many different meanings to humans -- you have a lot of emotional components," he said.

The results could give scientists a starting point for studies to determine whether the animal findings apply to humans, and ultimately could inform development of safer alternatives to opioids for treating pain.

Read more at Science Daily

Horses and pigs sense harsh speaking tones

How we speak matters to animals. Horses, pigs and wild horses can distinguish between negative and positive sounds from their fellow species and near relatives, as well as from human speech. This, according to new research in behavioral biology at the University of Copenhagen. The study provides insight into the history of emotional development and opens up interesting perspectives with regards to animal welfare.

The idea of horse whisperers -- those with a talent for communicating with horses -- may bring a chuckle to many. But according to new research from the University of Copenhagen and ETH Zurich, there may be something about their whispering skills. In an international collaboration, along with researchers Anne-Laure Maigrot and Edna Hillmann, behavioral biologist Elodie Briefer of the University of Copenhagen's Department of Biology investigated whether a range of animals can distinguish between positively and negatively charged sounds.

"The results showed that domesticated pigs and horses, as well as Asian wild horses, can tell the difference, both when the sounds come from their own species and near relatives, as well as from human voices," explains Elodie Briefer. Pigs were studied along with boar, their wild relatives. Just as in the case of the two related horse species, the pigs clearly reacted to how the sounds of their counterparts were emotionally charged. In fact, to the same extent as when it came to sounds of their own kind.

The animals even showed the ability to distinguish between positively or negatively charged human voices. While their reactions were more subdued, all but wild boars reacted differently when exposed to human speech that was either charged with positive or negative emotion.

Human gibberish

The researchers played recordings of animal sounds and human voices from hidden speakers.

To avoid having the domesticated animals react to specific words, positive and negative human speech was performed by a professional voice actor in a kind of gibberish without any meaningful phrases.

The animals' behavioral reactions were recorded in a number of categories used in previous studies -- everything from their ear position to their movement or lack thereof.

On this basis, the researchers concluded that: How we speak matters to animals.

"Our results show that these animals are affected by the emotions we charge our voices with when we speak to or are around them. They react more strongly -- generally faster -- when they are met with a negatively charged voice, compared to having a positively charged voice played to them first. In certain situations, they even seem to mirror the emotion to which they are exposed" says Elodie Briefer.

Do animals have an emotional life?

Part of the aim of the study, was to investigate the possibility of "emotional contagion" in animals -- a kind of mirroring of emotion. Situations where one expressed emotion is assumed by another. In behavioral biology, this type of reaction is seen as the first step in the empathy category.

"Should future research projects clearly demonstrate that these animals mirror emotions, as this study suggests, it will be very interesting in relation to the history of the development of emotions and the extent to which animals have an emotional life and level of consciousness," says Elodie Briefer.

The study was unable to detect clear observations of "emotional contagion," but an interesting result was in the order by which the sounds where delivered. Sequences in which the negative sound was played first triggered stronger reactions in all but the wild boars. This included human speech.

According to Elodie Briefer, this suggests that the way we talk around animals and the way we talk to animals may have an impact on their well-being.

"It means that our voices have a direct impact on the emotional state of animals, which is very interesting from an animal welfare perspective," she says.

This knowledge doesn't just raise ethical questions about how we perceive animals -- and vice versa, it can also be used as a concrete means of improving animals' daily lives, if those who work with them are familiar with it.

"When the animals reacted strongly to hearing negatively charged speech first, the same is also true in the reverse. That is, if animals are initially spoken to in a more positive, friendly voice, when met by people, they should react less. They may become calmer and more relaxed," explains Elodie Briefer.

Next step for the Copenhagen University researcher is the switchover. She and her colleagues, are now looking into how well we humans are able to understand animal sounds of emotion.

How the researchers did it
 

• The animals in the experiment were either privately owned (horses), from a research station (pigs) or living in zoos in Switzerland and France (wild Przewalski's horses and wild boars).
• The researchers used animal sounds with a previously established emotion valence.
• The animal sounds and human voices were played to the animals from hidden speakers.
• Doing so required high sound quality to ensure for the natural frequencies heard best by animals.
• The sounds were played in sequences with either a positive or negatively charged sound first, then a pause, -- and then sounds with reverse valence, i.e. the reverse emotion.
• The reactions were recorded on video, which the researchers could subsequently use to observe and record the animals' reactions.
• Three theses can explain the animal reactions

The researchers worked with three theories about which conditions they expected to influence the animals' reactions in the experiment:

Phylogeny
 

• According to this theory, depending on the evolution of species, i.e., the history of evolution, animals with a common ancestry may be able to perceive and interpret each other's sounds by virtue of their common biology.

Domestication
 

• Close contact with humans, over a long period of time, may have increased the ability to interpret human emotions.
• Animals that are good at picking up human emotions might have been preferred for breeding.

Familiarity
 

• Based on learning. The specific animals in the study may have learned a greater understanding of humans and fellow species, who they were in close contact with where they were housed.

The conclusion is as follows. Among the horse species, the phylogeny thesis best explained their behavior. In contrast, the behavior of the pig species best fit the domestication hypothesis.

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Tumors partially destroyed with sound don't come back

Noninvasive sound technology developed at the University of Michigan breaks down liver tumors in rats, kills cancer cells and spurs the immune system to prevent further spread -- an advance that could lead to improved cancer outcomes in humans.

By destroying only 50% to 75% of liver tumor volume, the rats' immune systems were able to clear away the rest, with no evidence of recurrence or metastases in more than 80% animals.

"Even if we don't target the entire tumor, we can still cause the tumor to regress and also reduce the risk of future metastasis," said Zhen Xu, professor of biomedical engineering at U-M and corresponding author of the study in Cancers.

Results also showed the treatment stimulated the rats' immune responses, possibly contributing to the eventual regression of the untargeted portion of the tumor and preventing further spread of the cancer.

The treatment, called histotripsy, noninvasively focuses ultrasound waves to mechanically destroy target tissue with millimeter precision. The relatively new technique is currently being used in a human liver cancer trial in the United States and Europe.

In many clinical situations, the entirety of a cancerous tumor cannot be targeted directly in treatments for reasons that include the mass' size, location or stage. To investigate the effects of partially destroying tumors with sound, this latest study targeted only a portion of each mass, leaving behind a viable intact tumor. It also allowed the team, including researchers at Michigan Medicine and the Ann Arbor VA Hospital, to show the approach's effectiveness under less than optimal conditions.

"Histotripsy is a promising option that can overcome the limitations of currently available ablation modalities and provide safe and effective noninvasive liver tumor ablation," said Tejaswi Worlikar, a doctoral student in biomedical engineering. "We hope that our learnings from this study will motivate future preclinical and clinical histotripsy investigations toward the ultimate goal of clinical adoption of histotripsy treatment for liver cancer patients."

Liver cancer ranks among the top 10 causes of cancer related deaths worldwide and in the U.S. Even with multiple treatment options, the prognosis remains poor with five-year survival rates less than 18% in the U.S. The high prevalence of tumor recurrence and metastasis after initial treatment highlights the clinical need for improving outcomes of liver cancer.

Where a typical ultrasound uses sound waves to produce images of the body's interior, U-M engineers have pioneered the use of those waves for treatment. And their technique works without the harmful side effects of current approaches such as radiation and chemotherapy.

"Our transducer, designed and built at U-M, delivers high amplitude microsecond-length ultrasound pulses -- acoustic cavitation -- to focus on the tumor specifically to break it up," Xu said. "Traditional ultrasound devices use lower amplitude pulses for imaging."

The microsecond long pulses from UM's transducer generate microbubbles within the targeted tissues -- bubbles that rapidly expand and collapse. These violent but extremely localized mechanical stresses kill cancer cells and break up the tumor's structure.

Since 2001, Xu's laboratory at U-M has pioneered the use of histotripsy in the fight against cancer, leading to the clinical trial #HOPE4LIVER sponsored by HistoSonics, a U-M spinoff company. More recently, the group's research has produced promising results on histotripsy treatment of brain therapy and immunotherapy.

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Perseverance records the first ever sounds from Mars

NASA's Perseverance rover, which has been surveying the surface of Mars since February 2021, has for the first time recorded the acoustic environment of the Red Planet. An international team led by an academic at the University of Toulouse III -- Paul Sabatier and including scientists from the CNRS and ISAE-SUPAERO, carried out an analysis of these sounds, which were obtained using the SuperCam instrument built in France under the authority of the French space agency CNES. Their findings are published on 1st April 2022 in Nature.

For 50 years, interplanetary probes have returned thousands of striking images of the surface of Mars, but never a single sound. Now, NASA's Perseverance mission has put an end to this deafening silence by recording the first ever Martian sounds. The scientific team for the French-US SuperCam instrument installed on Perseverance was convinced that the study of the soundscape of Mars could advance our understanding of the planet. This scientific challenge led them to design a microphone dedicated to the exploration of Mars, at ISAE-SUPAERO in Toulouse, France.

Perseverance first recorded sounds from the Red Planet on February 19, 2021, the day after its arrival. These sounds fall within the human audible spectrum, between 20 Hz and 20 kHz. First of all, they reveal that Mars is quiet, in fact so quiet that on several occasions the scientists thought the microphone was no longer working. It is obvious that, apart from the wind, natural sound sources are rare.

In addition to this investigation, the scientists focused on the sounds generated by the rover itself, including the shock waves produced by the impact of the SuperCam laser on rocks, and flights by the Ingenuity helicopter. By studying the propagation on Mars of these sounds, whose behaviour is very well well understood on Earth, they were able to accurately characterise the acoustic properties of the Martian atmosphere.

The researchers show that the speed of sound is lower on Mars than on Earth: 240 m/s, as compared to 340 m/s on our planet. However, the most surprising thing is that it turns out that there are actually two speeds of sound on Mars, one for high-pitched sounds and one for low frequencies. Sound attenuation is greater on Mars than on Earth, especially for high frequencies, which, unlike low frequencies, are attenuated very quickly, even at short distances. All these various factors would make it difficult for two people standing only five metres apart to have a conversation. They are due to the composition of the Martian atmosphere (96% CO2, compared to 0.04% on Earth) and the very low atmospheric surface pressure (170 times lower than on Earth).

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In a first for 'sonogenetics,' researchers control mammalian cells with sound

Salk scientists have engineered mammalian cells to be activated using ultrasound. The method, which the team used to activate human cells in a dish and brain cells inside living mice, paves the way toward non-invasive versions of deep brain stimulation, pacemakers and insulin pumps. The findings were published in Nature Communications on February 9, 2022.

"Going wireless is the future for just about everything," says senior author Sreekanth Chalasani, an associate professor in Salk's Molecular Neurobiology Laboratory. "We already know that ultrasound is safe, and that it can go through bone, muscle and other tissues, making it the ultimate tool for manipulating cells deep in the body."

About a decade ago, Chalasani pioneered the idea of using ultrasonic waves to stimulate specific groups of genetically marked cells, and coined the term "sonogenetics" to describe it. In 2015, his group showed that, in the roundworm Caenorhabditis elegans, a protein called TRP-4 makes cells sensitive to low-frequency ultrasound. When the researchers added TRP-4 to C. elegans neurons that didn't usually have it, they could activate these cells with a burst of ultrasound -- the same sound waves used in medical sonograms.

When the researchers tried adding TRP-4 to mammalian cells, however, the protein was not able to make the cells respond to ultrasound. A few mammalian proteins were reported to be ultrasound-sensitive, but none seemed ideal for clinical use. So Chalasani and his colleagues set out to search for a new mammalian protein that made cells highly ultrasound sensitive at 7 MHz, considered an optimal and safe frequency.

"Our approach was different than previous screens because we set out to look for ultrasound-sensitive channels in a comprehensive way," says Yusuf Tufail, a former project scientist at Salk and a co-first author of the new paper.

The researchers added hundreds of different proteins, one at a time, to a common human research cell line (HEK), which does not usually respond to ultrasound. Then, they put each cell culture under a setup that let them monitor changes to the cells upon ultrasound stimulation.

After screening proteins for more than a year, and working their way through nearly 300 candidates, the scientists finally found one that made the HEK cells sensitive to the 7 MHz ultrasound frequency. TRPA1, a channel protein, was known to let cells respond to the presence of noxious compounds and to activate a range of cells in the human body, including brain and heart cells.

But Chalasani's team discovered that the channel also opened in response to ultrasound in HEK cells.

"We were really surprised," says co-first author of the paper Marc Duque, a Salk exchange student. "TRPA1 has been well-studied in the literature but hasn't been described as a classical mechanosensitive protein that you'd expect to respond to ultrasound."

To test whether the channel could activate other cell types in response to ultrasound, the team used a gene therapy approach to add the genes for human TRPA1 to a specific group of neurons in the brains of living mice. When they then administered ultrasound to the mice, only the neurons with the TRPA1 genes were activated.

Clinicians treating conditions including Parkinson's disease and epilepsy currently use deep brain stimulation, which involves surgically implanting electrodes in the brain, to activate certain subsets of neurons. Chalasani says that sonogenetics could one day replace this approach -- the next step would be developing a gene therapy delivery method that can cross the blood-brain barrier, something that is already being studied.

Perhaps sooner, he says, sonogenetics could be used to activate cells in the heart, as a kind of pacemaker that requires no implantation. "Gene delivery techniques already exist for getting a new gene -- such as TRPA1 -- into the human heart," Chalasani says. "If we can then use an external ultrasound device to activate those cells, that could really revolutionize pacemakers."

For now, his team is carrying out more basic work on exactly how TRPA1 senses ultrasound. "In order to make this finding more useful for future research and clinical applications, we hope to determine exactly what parts of TRPA1 contribute to its ultrasound sensitivity and tweak them to enhance this sensitivity," says Corinne Lee-Kubli, a co-first author of the paper and former postdoctoral fellow at Salk.

They also plan to carry out another screen for ultrasound sensitive proteins -- this time looking for proteins that can inhibit, or shut off, a cell's activity in response to ultrasound.

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When the brain switches from hearing to listening

What happens in the brain when simply hearing becomes listening? To answer this question, researchers at the University of Basel have traced the neuronal fingerprint of the two types of sound processing in the mouse brain.

It is intuitively clear to us that there is a difference between passive hearing and active listening. Attention and an animated state, but also movement, play a role in how sound processing in the brain adjusts accordingly. Neuroscientists Professor Tania Rinaldi Barkat and Dr. Gioia De Franceschi from the Department of Biomedicine at the University of Basel have provided an accurate account of what happens in this process in the journal Cell Reports.

For their study, the researchers examined the activity of neurons in four different areas in the brains of mice known to be involved in increasingly complex sound processing. During the experiment, the animals were either passively hearing the sounds played to them, or actively listening to them to receive a reward for detecting the sounds.

Activity pattern depends on various factors

It was shown that the majority of neurons changed their activity when switching between hearing and listening. "But this doesn't mean that all neurons behaved the same way," explains De Franceschi. "We actually found ten distinct and specific types of activity change."

While most of the neurons showed a change that was probably related to varying levels of attention, some of them also showed patterns of activity that were related to the arousal level of the mice, their movement, the availability of a reward, or a combination of these factors.

Impact on all processing levels

The auditory pathway in the brain consists of a number of different nuclei that relay acoustic information from the cochlea to the primary auditory cortex. Two of the four areas along the auditory pathway studied by the researchers are thought to be at a "higher level" in terms of processing complexity. "At the beginning of our study, we suspected that these were the areas particularly affected by attention to sounds," said Barkat. "Surprisingly, however, this wasn't the case." Attention also alters activity in brain areas previously thought to perform only basic forms of sound processing.

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Speaking 'baby talk' to infants isn’t just cute: It could help them learn to make words

A new study suggests that when parents baby talk to their infants, they might be helping them learn to produce speech.

The way we instinctively speak to babies -- higher pitch, slower speed, exaggerated pronunciation -- not only appeals to them, but likely helps them learn to understand what we're saying. New research from the University of Florida suggests that baby talk can have another, previously unknown benefit: helping babies learn to produce their own speech. By mimicking the sound of a smaller vocal tract, the researchers think, we're cluing babies in to how the words should sound coming out of their own mouths.

"It seems to stimulate motor production of speech, not just the perception of speech," said Matthew Masapollo, Ph.D., an assistant professor in UF's Department of Speech, Language, and Hearing Sciences and director of the UF Laboratory for the Study of Cognition, Action, and Perception of Speech in the College of Public Health and Health Professions. "It's not just goo-goo ga-ga."

In the study, the researchers changed the frequency sounds to mimic either an infant or adult vocal tract, and then tested how infants reacted. Six- to eight-month-old babies "displayed a robust and distinct preference for speech with resonances specifying a vocal tract that is similar in size and length to their own," they wrote.

Four- to six-month old babies didn't have that preference, suggesting that older babies' dawning ability to control their voices and make words out of babble could be what makes the infant-like sounds more appealing.

Though baby talk may sound simple, it's accomplishing a lot, says coauthor Linda Polka, Ph.D., of McGill University.

"We're trying to engage with the infant to show them something about speech production," she said. "We're priming them to process their own voice."

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A new approach to identify mammals good at learning sounds

Why are some animals good at learning sounds? Did this skill appear when animals started 'faking' their body size by lowering calls? In a new study on a wide range of mammals,researchers revisit this question. Surprisingly, many animals who are skilled vocalists (such as dolphins and seals) actually sound higher than would be expected for their body size.

Some animals -- such as red deer -- sound 'bigger' than they really are. This means that their calls are lower than you would expect based on their body size. Biologists think that 'faking' body size in such a way might be a strategy to impress the other sex. In a recent study, Garcia and Ravignani noticed that animals who can fake their body size by changing their calls also tend to be good at learning sounds -- an ability known as vocal learning. Could natural selection be the driving force behind both: faking body size and learning sounds? If true, this idea would have important implications for the evolution of speech.

To further explore the relationship between faking body size and vocal learning, Ravignani and Garcia expanded their earlier analyses of a wide range of mammals. Would the relation between faking body size and learning sounds turn out to be a systematic evolutionary pattern?

What they found was surprising. Contrary to expectations, most vocal learners -- such as dolphins, whales and seals -- sounded higher than you would expect based on their body size, not lower. Ravignani explains: "There might be an alternative evolutionary scenario in vocal learners, where selective pressures favour individuals that can change their tone of voice from low to high." In other words, good vocal learners are those animals that can hit the high notes. Vocal learners who sounded lower than expected often had anatomical adaptations that could explain the lowered voice (such as a longer nose). Garcia adds: "Of course there are exceptions, and we do not claim that all vocal learner species sound higher than expected for their body size. But there is a general trend, and this may help us to better characterise vocal communication in mammals."

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Acoustic illusions

When listening to music, we don't just hear the notes produced by the instruments, we are also immersed in its echoes from our surroundings. Sound waves bounce back off the walls and objects around us, forming a characteristic sound effect -- a specific acoustic field. This explains why the same piece of music sounds very different when played in an old church or a modern concrete building.

Architects have long been capitalising on this fact when building, say, concert halls. However, the principle can also be transferred to other applications: objects hidden underground can be visualised by measuring how sound waves from a known source are reflected.

Active and passive manipulation

Some scientists want to go one step further and systematically manipulate the acoustic field to achieve an effect that shouldn't exist per se, given the real-life situation. For instance, they are attempting to create an illusory audio experience that tricks the listener into believing they are in a concrete building or an old church. Alternatively, objects can be made invisible by manipulating the acoustic field in such a way that the listener no longer perceives them.

Usually, the desired illusion relies on using passive methods that involve structuring the surfaces with the help of what are known as metamaterials. One way of hiding an object acoustically is to coat its surface and stop it from reflecting any sound waves. However, this approach is inflexible and usually works only within a limited frequency range, making it unsuitable for many applications.

Active methods seek to achieve the illusion by superimposing another layer of sound waves. In other words, by adding a second signal to the initial acoustic field. However, until now the scope for using this approach has also been limited, as it works only if the initial field can be predicted with some certainty.

Real-time illusion

Now the group headed by Johan Robertsson, Professor of Applied Geophysics at ETH Zurich, has worked with scientists from the University of Edinburgh to develop a new concept that significantly improves the active illusion. Led by Theodor Becker, a postdoc in Robertsson's group, and Dirk-Jan van Manen, the senior scientist who was instrumental in designing the experiments, the researchers have managed to augment the initial field in real time, as they report in the latest issue of the journal Science Advances. As a result, they can make objects disappear and they can mimic non-existent ones.

To achieve the special acoustic effects, the researchers installed a large test facility for the project in the Centre for Immersive Wave Experimentation at the Switzerland Innovation Park Zurich in Dübendorf. Specifically, this facility allows them to mask the existence of an object measuring roughly 12 centimetres or simulate an imaginary object of equal size.

The target object is enclosed in an outer ring of microphones as control sensors and an inner ring of loudspeakers as control sources. The control sensors register which external acoustic signals reach the object from the initial field. Based on these measurements, a computer then calculates which secondary sounds the control sources must produce to achieve the desired augmentation of the initial field.

Sophisticated technology

To mask the object, the control sources emit a signal that completely obliterates the sound waves reflected off the object. By contrast, to simulate an object (also known as holography), the control sources augment the initial acoustic field as if sound waves were bouncing off an object at the centre of the two rings.

For this augmentation to work, the data measured by the control sensors must be transformed instantaneously into instructions for the control sources. To control the system, the researchers therefore use field-programmable gate arrays (FPGAs) with an extremely short response time.

"Our facility allows us to manipulate the acoustic field over a frequency range of more than three and a half octaves," Robertsson says. The maximum frequency for cloaking is 8,700 Hz and 5,900 Hz for simulating. To date, the researchers have been able to manipulate the acoustic field on a surface in two dimensions. As a next step, they want to increase the process to three dimensions and extend its functional range. The system currently augments airborne sound waves. However, Robertsson explains, the new process could also produce acoustic illusions under water. He envisages a vast array of potential uses in different fields, such as sensor technology, architecture and communications, as well as in the education sector.

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What does your voice say about you?

Everyone has at some point been charmed by the sound of a person's voice: but can we believe our ears? What can a voice really reveal about our character? Now an international research team led by the University of Göttingen has shown that people seem to express at least some aspects of their personality with their voice. The researchers discovered that a lower pitched voice is associated with individuals who are more dominant, extrovert and higher in sociosexuality (more interested in casual sex). The findings were true for women as well as for men. The results were published in the Journal of Research in Personality.

The researchers analysed data from over 2,000 participants and included information from four different countries. Participants filled in questionnaires about themselves to measure personality and provided recordings of their voice so that the pitch could be measured using a computer programme. This is the first time that an objective digital measure of voice pitch has been used in a study of this kind, rather than subjective ratings of how "high" or "deep" a voice might sound. The researchers measured "sociosexuality" by collecting responses about sexual behaviour, attitude and desire. They also collected data to provide ratings of dominance and other character traits such as neuroticism, extraversion, openness to experience, agreeableness and conscientiousness. The number of participants helps to confirm the robustness of the findings: the study involves the largest number to date compared to similar research in this theme.

The researchers found that people with lower pitched voices were more dominant, extroverted and higher in sociosexuality (eg were more interested in sex outside a relationship). However, the relationship between voice pitch and other personality traits (such as agreeableness, neuroticism, conscientiousness or openness) seems less clear. It is possible that these traits are not expressed in the pitch of voices. The researchers found no difference between men and women.

"People's voices can make a huge and immediate impression on us," explains Dr Julia Stern, at the University of Göttingen's Biological Personality Psychology Group. "Even if we just hear someone's voice without any visual clues -- for instance on the phone -- we know pretty soon whether we're talking to a man, a woman, a child or an older person. We can pick up on whether the person sounds interested, friendly, sad, nervous, or whether they have an attractive voice. We also start to make assumptions about trust and dominance." This led Stern to question whether these assumptions were justified. "The first step was to investigate whether voices are, indeed, related to people's personality. And our results suggest that people do seem to express some aspects of their personality with their voice."

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How we retrieve our knowledge about the world

To understand the world, we arrange individual objects, people, and events into different categories or concepts. Concepts such as 'the telephone' consist primarily of visible features, i.e. shape and color, and sounds, such as ringing. In addition, there are actions, i.e. how we use a telephone.

However, the concept of telephone does not only arise in the brain when we have a telephone in front of us. It also appears when the term is merely mentioned. If we read the word "telephone," our brain also calls up the concept of telephone. The same regions in the brain are activated that would be activated if we actually saw, heard, or used a telephone. The brain thus seems to simulate the characteristics of a telephone when its name alone is mentioned.

Until now, however, it was unclear, depending on the situation, whether the entire concept of a telephone is called up or only individual features such as sounds or actions and whether only the brain areas that process the respective feature become active. So, when we think of a telephone, do we always think of all its features or only the part that is needed at the moment? Do we retrieve our sound knowledge when a phone rings, but our action knowledge when we use it?

Researchers at the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig have now found the answer: It depends on the situation. If, for example, the study participants thought of the sounds associated with the word "telephone," the corresponding auditory areas in the cerebral cortex were activated, which are also activated during actual hearing. When thinking about using a telephone, the somatomotor areas that underlie the involved movements came into action.

In addition to these sensory-dependent, so-called modality-specific areas, it was found that there are areas that process both sounds and actions together. One of these so-called multimodal areas is the left inferior parietal lobule (IPL). It became active when both features were requested.

The researchers also found out that, in addition to characteristics based on sensory impressions and actions, there must be other criteria by which we understand and classify terms. This became apparent when the participants were only asked to distinguish between real and invented words. Here, a region that was not active for actions or sounds kicked in: the so-called anterior temporal lobe (ATL). The ATL therefore seems to process concepts abstractly or "amodally," completely detached from sensory impressions.

From these findings, the scientists finally developed a hierarchical model to reflect how conceptual knowledge is represented in the human brain. According to this model, information is passed on from one hierarchical level to the next and at the same time becomes more abstract with each step. On the lowest level, therefore, are the modality-specific areas that process individual sensory impressions or actions. These transmit their information to the multimodal regions such as the IPL, which process several linked perceptions simultaneously, such as sounds and actions. The amodal ATL, which represents features detached from sensory impressions, operates at the highest level. The more abstract a feature, the higher the level at which it is processed and the further it is removed from actual sensory impressions.

"We thus show that our concepts of things, people, and events are composed, on the one hand, of the sensory impressions and actions associated with them and, on the other hand, of abstract symbol-like features," explains Philipp Kuhnke, lead author of the study, which was published in the journal Cerebral Cortex. "Which features are activated depends strongly on the respective situation or task" added Kuhnke.

In a follow-up study in Cerebral Cortex, the researchers also found that modality-specific and multimodal regions work together in a situation-dependent manner when we retrieve conceptual features. The multimodal IPL interacted with auditory areas when retrieving sounds, and with somatomotor areas when retrieving actions. This showed that the interaction between modality-specific and multimodal regions determined the behavior of the study participants. The more these regions worked together, the more strongly the participants associated words with actions and sounds.

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