Picking Up Good Vibrations: The Surprising Physics of the Didjeridu #Acoustics23

Playing Australia’s most iconic instrument requires producing vibrations inside the vocal tract.

SYDNEY, Dec. 6, 2023 – Australia’s most iconic sound is almost certainly the didjeridu. The long wooden tube-shaped instrument is famous for its unique droning music and has played a significant role in Australian Aboriginal culture for thousands of years. Despite the instrument’s simple design, the playing technique can be highly complex.

Joe Wolfe and John Smith from the University of New South Wales conducted acoustic experiments to study the didjeridu’s unusual and complicated performance techniques. Smith will be presenting their work on Dec. 6 at 8:20 a.m. Australian Eastern Daylight Time, as part of Acoustics 2023 Sydney, running Dec. 4-8 at the International Convention Centre Sydney.

Producing complex sounds with the didjeridu requires creating and manipulating resonances inside the vocal tract. Credit: Kate Callas

“We were interested in the effect of the player’s vocal tract on various wind instruments,” said Smith. “The didjeridu seemed like an obvious start because the effect is so striking.”

Much more than with almost any other instrument, a didjeridu player uses his vocal tract and vocal folds to produce striking changes in timbre.

“Resonances in the mouth tend to remove bands of frequencies in the didjeridu sound and we notice the remaining bands,” said Smith. “It’s a bit like a sculptor removing marble to leave the things that we notice.”

To study didjeridu performance, the team developed new experimental techniques. One involved injecting a broadband acoustic signal into a player’s mouth to measure the acoustic impedance spectrum of a didjeridu player’s vocal tract. The impedance spectrum is an indicator of which frequencies will resonate and which will be suppressed.

This information let Smith and his colleagues identify traits that make the best didjeridus, explore advanced techniques musicians use to create more complicated sounds, and expand their studies to other wind instruments.

In another study, the team were able to identify and understand the acoustic properties of didjeridus most preferred by expert players; these can be very different from the properties of other wind instruments.

“We looked at advanced performance techniques, not only in the didjeridu, but also in other wind instruments, such as clarinet and saxophone,” said Smith. “We continue to research subtle features of expressive playing of wind instruments.”

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Contact:
AIP Media
301-209-3090
media@aip.org

———————– MORE MEETING INFORMATION ———————–

The Acoustical Society of America is joining the Australian Acoustical Society to co-host Acoustics 2023 Sydney. This collaborative event will incorporate the Western Pacific Acoustics Conference and the Pacific Rim Underwater Acoustics Conference.

Main meeting website: https://acoustics23sydney.org/
Technical program: https://eppro01.ativ.me/src/EventPilot/php/express/web/planner.php?id=ASAFALL23

ASA PRESS ROOM
In the coming weeks, ASA’s Press Room will be updated with newsworthy stories and the press conference schedule at https://acoustics.org/asa-press-room/.

LAY LANGUAGE PAPERS
ASA will also share dozens of lay language papers about topics covered at the conference. Lay language papers are summaries (300-500 words) of presentations written by scientists for a general audience. They will be accompanied by photos, audio, and video. Learn more at
https://acoustics.org/lay-language-papers/.

PRESS REGISTRATION
ASA will grant free registration to credentialed and professional freelance journalists. If you are a reporter and would like to attend the meeting or virtual press conferences, contact AIP Media Services at media@aip.org. For urgent requests, AIP staff can also help with setting up interviews and obtaining images, sound clips, or background information.

ABOUT THE ACOUSTICAL SOCIETY OF AMERICA
The Acoustical Society of America (ASA) is the premier international scientific society in acoustics devoted to the science and technology of sound. Its 7,000 members worldwide represent a broad spectrum of the study of acoustics. ASA publications include The Journal of the Acoustical Society of America (the world’s leading journal on acoustics), JASA Express Letters, Proceedings of Meetings on Acoustics, Acoustics Today magazine, books, and standards on acoustics. The society also holds two major scientific meetings each year. See https://acousticalsociety.org/.

ABOUT THE AUSTRALIAN ACOUSTICAL SOCIETY
The Australian Acoustical Society (AAS) is the peak technical society for individuals working in acoustics in Australia. The AAS aims to promote and advance the science and practice of acoustics in all its branches to the wider community and provide support to acousticians. Its diverse membership is made up from academia, consultancies, industry, equipment manufacturers and retailers, and all levels of Government. The Society supports research and provides regular forums for those who practice or study acoustics across a wide range of fields The principal activities of the Society are technical meetings held by each State Division, annual conferences which are held by the State Divisions and the ASNZ in rotation, and publication of the journal Acoustics Australia. https://www.acoustics.org.au/

Wearable Ultrasound Monitor Can Aid Rehabilitation from Injury #Acoustics23

A new approach to ultrasound imaging can provide real-time insights into muscle dynamics.

SYDNEY, Dec. 5, 2023 – Millions suffer from musculoskeletal injuries every year, and the recovery process can often be long and difficult. Patients typically undergo rehabilitation, slowly rebuilding muscle strength as their injuries heal. Medical professionals routinely evaluate a patient’s progress via a series of tasks and exercises. However, because of the dynamic nature of these exercises, obtaining a clear picture of real-time muscle function is extremely challenging.

Parag Chitnis of George Mason University led a team that developed a wearable ultrasound system that can produce clinically relevant information about muscle function during dynamic physical activity. He will present his work Dec. 5 at 5:00 p.m. Australian Eastern Daylight Time, as part of Acoustics 2023 running Dec. 4-8 at the International Convention Centre Sydney

A wearable ultrasound monitor can provide insight into dynamic muscle movement during activities like jumping. Credit: Parag Chitnis

Many medical technologies can give doctors a window into the inner workings of a patient’s body, but few can be used while that patient is moving. A wearable ultrasound monitor can move with the patient and provide an unprecedented level of insight into body dynamics.

“For instance, when an individual is performing a specific exercise for rehabilitation, our devices can be used to ensure that the target muscle is actually being activated and used correctly,” said Chitnis. “Other applications include providing athletes with insights into their physical fitness and performance, assessing and guiding recovery of motor function in stroke patients, and assessing balance and stability in elderly populations during routine everyday tasks.”

Designing a wearable ultrasound device took much more than simply strapping an existing ultrasound monitor to a patient. Chitnis and his team reinvented ultrasound technology nearly from scratch to produce the results they needed.

“We had to completely change the paradigm of ultrasound imaging,” said Chitnis. “Traditionally, ultrasound systems transmit short-duration pulses, and the echo signals are used to make clinically usefully images. Our systems use a patented approach that relies on transmission of long-duration chirps, which allows us to perform ultrasound sensing using the same components one might find in their car radio.”

This modified approach allowed the team to design a simpler, cheaper system that could be miniaturized and powered by batteries. This let them design an ultrasound monitor with a small, portable form factor that could be attached to a patient.

Soon, Chitnis hopes to further improve his device and develop software tools to more quickly interpret and analyze the ultrasound signals.

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Contact:
AIP Media
301-209-3090
media@aip.org

———————– MORE MEETING INFORMATION ———————–

The Acoustical Society of America is joining the Australian Acoustical Society to co-host Acoustics 2023 Sydney. This collaborative event will incorporate the Western Pacific Acoustics Conference and the Pacific Rim Underwater Acoustics Conference.

Main meeting website: https://acoustics23sydney.org/
Technical program: https://eppro01.ativ.me/src/EventPilot/php/express/web/planner.php?id=ASAFALL23

ASA PRESS ROOM
In the coming weeks, ASA’s Press Room will be updated with newsworthy stories and the press conference schedule at https://acoustics.org/asa-press-room/.

LAY LANGUAGE PAPERS
ASA will also share dozens of lay language papers about topics covered at the conference. Lay language papers are summaries (300-500 words) of presentations written by scientists for a general audience. They will be accompanied by photos, audio, and video. Learn more at
https://acoustics.org/lay-language-papers/.

PRESS REGISTRATION
ASA will grant free registration to credentialed and professional freelance journalists. If you are a reporter and would like to attend the meeting or virtual press conferences, contact AIP Media Services at media@aip.org. For urgent requests, AIP staff can also help with setting up interviews and obtaining images, sound clips, or background information.

ABOUT THE ACOUSTICAL SOCIETY OF AMERICA
The Acoustical Society of America (ASA) is the premier international scientific society in acoustics devoted to the science and technology of sound. Its 7,000 members worldwide represent a broad spectrum of the study of acoustics. ASA publications include The Journal of the Acoustical Society of America (the world’s leading journal on acoustics), JASA Express Letters, Proceedings of Meetings on Acoustics, Acoustics Today magazine, books, and standards on acoustics. The society also holds two major scientific meetings each year. See https://acousticalsociety.org/.

ABOUT THE AUSTRALIAN ACOUSTICAL SOCIETY
The Australian Acoustical Society (AAS) is the peak technical society for individuals working in acoustics in Australia. The AAS aims to promote and advance the science and practice of acoustics in all its branches to the wider community and provide support to acousticians. Its diverse membership is made up from academia, consultancies, industry, equipment manufacturers and retailers, and all levels of Government. The Society supports research and provides regular forums for those who practice or study acoustics across a wide range of fields The principal activities of the Society are technical meetings held by each State Division, annual conferences which are held by the State Divisions and the ASNZ in rotation, and publication of the journal Acoustics Australia. https://www.acoustics.org.au/

A Farsighted Approach to Tackle Nearsightedness #Acoustics23

Acoustical imaging helps reveal causes and potential cures of myopia.

SYDNEY, Dec. 5, 2023 – Modern living may be contributing to an epidemic of nearsighted vision and related blindness. By 2050, it is estimated that half the world’s population will suffer from low vision due to myopia, a condition where the eye grows too large and can no longer focus on objects in the distance. Human eyes, honed by evolution to survive in the wild, are ill-adapted to city living, contributing to increased cases of myopia, among other factors.

For decades, researcher Sally McFadden from the University of Newcastle has investigated eyes and eyesight in humans and animals. She will present her work and the importance of acoustical imaging Dec. 5 at 10:40 a.m. Australian Eastern Daylight Time, as part of Acoustics 2023 Sydney, running Dec. 4-8 at the International Convention Centre Sydney.

Near-sightedness is on the rise, likely due to modern lifestyles that require seeing objects up close, rather than adjusting to vision in the distance. Credit: American Institute of Physics

As humans age, our eyes adjust based on how we use them, growing or shortening to focus where needed. We now know that blurred input to the eye while the eye is growing causes myopia. It is so specific that the eye grows exactly to compensate for the amount and the direction of blur. For example, if you put the focus behind the retina, the eye grows longer, while if you put the focus in front of the retina, the eye slows its growth and becomes shorter. If the eye grows too long, it becomes myopic or nearsighted. In extreme cases, high myopia is associated with glaucoma, and can increase the risk of retinal detachment and abnormal pathologies around the optic nerve which lead to profound blindness.

“Babies are generally born longsighted, and the changes in the optics of the eye have to coordinate with the eye growth to get to the perfect length for focused vision,” said McFadden. “The problem is that the human eye evolved to suit a hunter-gatherer lifestyle and is not adapted for modern living.”

McFadden and her team built a high-frequency ultrasonography system to measure eye size and how quickly eyes grow to better understand myopia and its contributing factors.

“Education level (amount of study) and the type of light stimulation to the eye all correlate with the amount of myopia you develop,” McFadden said. “Time spent outdoors is protective. Myopia is greater in cities than in rural populations, and even correlates with those that live in small homes.”

Currently, vision-correcting gear like glasses and contacts are the only solution for myopia. However, eyedrops for children with myopia are in development and could halt the vision from worsening. Teams from around the world are collaborating to develop treatments for high myopia to preserve our vision.

###

Contact:
AIP Media
301-209-3090
media@aip.org

———————– MORE MEETING INFORMATION ———————–

The Acoustical Society of America is joining the Australian Acoustical Society to co-host Acoustics 2023 Sydney. This collaborative event will incorporate the Western Pacific Acoustics Conference and the Pacific Rim Underwater Acoustics Conference.

Main meeting website: https://acoustics23sydney.org/
Technical program: https://eppro01.ativ.me/src/EventPilot/php/express/web/planner.php?id=ASAFALL23

ASA PRESS ROOM
In the coming weeks, ASA’s Press Room will be updated with newsworthy stories and the press conference schedule at https://acoustics.org/asa-press-room/.

LAY LANGUAGE PAPERS
ASA will also share dozens of lay language papers about topics covered at the conference. Lay language papers are summaries (300-500 words) of presentations written by scientists for a general audience. They will be accompanied by photos, audio, and video. Learn more at
https://acoustics.org/lay-language-papers/.

PRESS REGISTRATION
ASA will grant free registration to credentialed and professional freelance journalists. If you are a reporter and would like to attend the meeting or virtual press conferences, contact AIP Media Services at media@aip.org. For urgent requests, AIP staff can also help with setting up interviews and obtaining images, sound clips, or background information.

ABOUT THE ACOUSTICAL SOCIETY OF AMERICA
The Acoustical Society of America (ASA) is the premier international scientific society in acoustics devoted to the science and technology of sound. Its 7,000 members worldwide represent a broad spectrum of the study of acoustics. ASA publications include The Journal of the Acoustical Society of America (the world’s leading journal on acoustics), JASA Express Letters, Proceedings of Meetings on Acoustics, Acoustics Today magazine, books, and standards on acoustics. The society also holds two major scientific meetings each year. See https://acousticalsociety.org/.

ABOUT THE AUSTRALIAN ACOUSTICAL SOCIETY
The Australian Acoustical Society (AAS) is the peak technical society for individuals working in acoustics in Australia. The AAS aims to promote and advance the science and practice of acoustics in all its branches to the wider community and provide support to acousticians. Its diverse membership is made up from academia, consultancies, industry, equipment manufacturers and retailers, and all levels of Government. The Society supports research and provides regular forums for those who practice or study acoustics across a wide range of fields The principal activities of the Society are technical meetings held by each State Division, annual conferences which are held by the State Divisions and the ASNZ in rotation, and publication of the journal Acoustics Australia. https://www.acoustics.org.au/

Needle-Free Ultrasound Vaccine Delivery #Acoustics23

Technique employs bubbles formed and popped in response to sound waves to deliver vaccines and achieve potentially improved immune response.

SYDNEY, Dec. 4, 2023 – An estimated quarter of adults and two-thirds of children have strong fears around needles, according to the U.S. Centers for Disease Control and Prevention. Yet, public health depends on people being willing to receive vaccines, which are often administered by a jab.

Darcy Dunn-Lawless, a doctoral student at the University of Oxford’s Institute of Biomedical Engineering, is investigating the potential of a painless, needle-free vaccine delivery by ultrasound. He will share the recent advancements in this promising technique as part of Acoustics 2023 Sydney, running Dec. 4-8 at the International Convention Centre Sydney. His presentation will take place Dec. 4 at 11:00 a.m. Australian Eastern Daylight Time.

“Our method relies on an acoustic effect called ‘cavitation,’ which is the formation and popping of bubbles in response to a sound wave,” said Dunn-Lawless. “We aim to harness the concentrated bursts of mechanical energy produced by these bubble collapses in three main ways. First, to clear passages through the outer layer of dead skin cells and allow vaccine molecules to pass through. Second, to act as a pump that drives the drug molecules into these passages. Lastly, to open up the membranes surrounding the cells themselves, since some types of vaccine must get inside a cell to function.”

Though initial in vivo tests reported 700 times fewer vaccine molecules were delivered by the cavitation approach compared to conventional injection, the cavitation approach produced a higher immune response. The researchers theorize this could be due to the immune-rich skin the ultrasonic delivery targets in contrast to the muscles that receive the jab. The result is a more efficient vaccine that could help reduce costs and increase efficacy with little risk of side effects.

“In my opinion, the main potential side effect is universal to all physical techniques in medicine: If you apply too much energy to the body, you can damage tissue,” Dunn-Lawless said. “Exposure to excessive cavitation can cause mechanical damage to cells and structures. However, there is good evidence that such damage can be avoided by limiting exposure, so a key part of my research is to try and fully identify where this safety threshold lies for vaccine delivery.”

Ultrasound pulses deliver vaccines through the skin without needles. This technique, which employs sound waves to create bubbles that forge a path for the vaccine, may be especially helpful for DNA vaccines. Credit: Darcy Dunn-Lawless

Dunn-Lawless works as part of a larger team under the supervision of Dr. Mike Gray, Professor Bob Carlisle, and Professor Constantin Coussios within Oxford’s Biomedical Ultrasonics, Biotherapy and Biopharmaceuticals Laboratory (BUBBL). Their cavitation approach may be particularly conducing to DNA vaccines that are currently difficult to deliver. With cavitation able to help crack open the membranes blocking therapeutic access to the cell nucleus, the other advantages of DNA vaccines, like a focused immune response, low infection risk, and shelf stability, can be better utilized.

###

Contact:
AIP Media
301-209-3090
media@aip.org

———————– MORE MEETING INFORMATION ———————–

The Acoustical Society of America is joining the Australian Acoustical Society to co-host Acoustics 2023 Sydney. This collaborative event will incorporate the Western Pacific Acoustics Conference and the Pacific Rim Underwater Acoustics Conference.

Main meeting website: https://acoustics23sydney.org/
Technical program: https://eppro01.ativ.me/src/EventPilot/php/express/web/planner.php?id=ASAFALL23

ASA PRESS ROOM
In the coming weeks, ASA’s Press Room will be updated with newsworthy stories and the press conference schedule at https://acoustics.org/asa-press-room/.

LAY LANGUAGE PAPERS
ASA will also share dozens of lay language papers about topics covered at the conference. Lay language papers are summaries (300-500 words) of presentations written by scientists for a general audience. They will be accompanied by photos, audio, and video. Learn more at
https://acoustics.org/lay-language-papers/.

PRESS REGISTRATION
ASA will grant free registration to credentialed and professional freelance journalists. If you are a reporter and would like to attend the meeting or virtual press conferences, contact AIP Media Services at media@aip.org. For urgent requests, AIP staff can also help with setting up interviews and obtaining images, sound clips, or background information.

ABOUT THE ACOUSTICAL SOCIETY OF AMERICA
The Acoustical Society of America (ASA) is the premier international scientific society in acoustics devoted to the science and technology of sound. Its 7,000 members worldwide represent a broad spectrum of the study of acoustics. ASA publications include The Journal of the Acoustical Society of America (the world’s leading journal on acoustics), JASA Express Letters, Proceedings of Meetings on Acoustics, Acoustics Today magazine, books, and standards on acoustics. The society also holds two major scientific meetings each year. See https://acousticalsociety.org/.

ABOUT THE AUSTRALIAN ACOUSTICAL SOCIETY
The Australian Acoustical Society (AAS) is the peak technical society for individuals working in acoustics in Australia. The AAS aims to promote and advance the science and practice of acoustics in all its branches to the wider community and provide support to acousticians. Its diverse membership is made up from academia, consultancies, industry, equipment manufacturers and retailers, and all levels of Government. The Society supports research and provides regular forums for those who practice or study acoustics across a wide range of fields The principal activities of the Society are technical meetings held by each State Division, annual conferences which are held by the State Divisions and the ASNZ in rotation, and publication of the journal Acoustics Australia. https://www.acoustics.org.au/

Teaching Physics from the Din of Flying Discs #Acoustics23

Analyzing the sound of sailing discs can teach valuable signal processing lessons in an interactive way.

SYDNEY, Dec. 4, 2023 – Disc golf is booming, with record numbers of players turning up each year to partake in the disc-throwing sport. It is also whizzing and whistling. In fact, the sound a disc makes while soaring through the air toward its target is full of information about how fast the disc is flying and how quickly it spins.

This insight inspired Kyle S. Dalton of Penn State University to combine his two interests, disc golf and acoustics, into an interactive acoustic signal processing lesson. Dalton will present his work Dec. 4 at 3:40 p.m. Australian Eastern Daylight Time as part of Acoustics 2023, running Dec. 4-8 at the International Convention Centre Sydney.

Action shot of a person throwing a disc. This athletic pastime can help teach valuable lessons about signal processing by measuring the disc’s sound as it flies. Credit: Kyle S. Dalton

“When I took the introductory signal processing course in the acoustics curriculum, some of the example datasets we used came from noise sources such as aircraft, racecars, and fireworks displays,” said Dalton. “These datasets were effective for teaching new signal processing techniques, but those noise sources aren’t accessible to most students if they want to collect more data or experiment on their own.”

Dalton set three microphones in a line, spaced 25 feet apart, and connected them to equipment that converts each microphone’s signal to a data point on the computer. When he threw a disc with a small whistle mounted on top across the line of microphones, he recorded the flying disc’s acoustical signal.

“Listening to the disc allows me to capture multiple properties of the disc’s flight and observe the disc over a larger portion of its flight than is possible with some other measurement techniques,” Dalton said. “Radar guns are often used in disc golf to measure throw velocity, but don’t provide information on how fast the disc is spinning.”

Students can use the resulting dataset to learn basic processing tools and practice data visualization, using the Doppler shift to determine velocity, among other important lessons.

This experiment can be done in an open space, with a basic setup, and a practiced arm.

###

Contact:
AIP Media
301-209-3090
media@aip.org

———————– MORE MEETING INFORMATION ———————–

The Acoustical Society of America is joining the Australian Acoustical Society to co-host Acoustics 2023 Sydney. This collaborative event will incorporate the Western Pacific Acoustics Conference and the Pacific Rim Underwater Acoustics Conference.

Main meeting website: https://acoustics23sydney.org/
Technical program: https://eppro01.ativ.me/src/EventPilot/php/express/web/planner.php?id=ASAFALL23

ASA PRESS ROOM
In the coming weeks, ASA’s Press Room will be updated with newsworthy stories and the press conference schedule at https://acoustics.org/asa-press-room/.

LAY LANGUAGE PAPERS
ASA will also share dozens of lay language papers about topics covered at the conference. Lay language papers are summaries (300-500 words) of presentations written by scientists for a general audience. They will be accompanied by photos, audio, and video. Learn more at
https://acoustics.org/lay-language-papers/.

PRESS REGISTRATION
ASA will grant free registration to credentialed and professional freelance journalists. If you are a reporter and would like to attend the meeting or virtual press conferences, contact AIP Media Services at media@aip.org. For urgent requests, AIP staff can also help with setting up interviews and obtaining images, sound clips, or background information.

ABOUT THE ACOUSTICAL SOCIETY OF AMERICA
The Acoustical Society of America (ASA) is the premier international scientific society in acoustics devoted to the science and technology of sound. Its 7,000 members worldwide represent a broad spectrum of the study of acoustics. ASA publications include The Journal of the Acoustical Society of America (the world’s leading journal on acoustics), JASA Express Letters, Proceedings of Meetings on Acoustics, Acoustics Today magazine, books, and standards on acoustics. The society also holds two major scientific meetings each year. See https://acousticalsociety.org/.

ABOUT THE AUSTRALIAN ACOUSTICAL SOCIETY
The Australian Acoustical Society (AAS) is the peak technical society for individuals working in acoustics in Australia. The AAS aims to promote and advance the science and practice of acoustics in all its branches to the wider community and provide support to acousticians. Its diverse membership is made up from academia, consultancies, industry, equipment manufacturers and retailers, and all levels of Government. The Society supports research and provides regular forums for those who practice or study acoustics across a wide range of fields The principal activities of the Society are technical meetings held by each State Division, annual conferences which are held by the State Divisions and the ASNZ in rotation, and publication of the journal Acoustics Australia. https://www.acoustics.org.au/