Would a Musical Triangle of Any Other Shape Sound as Sweet?
The surprising proof of resonance in the open-ended musical triangle could exist in circles and squares too.
For the triangle, researchers captured proof that resonance occurs even with the notched, open corner, and it may occur in other instrument shapes as well. Credit: Risako Tanigawa
WASHINGTON, May 6, 2025 – The triangle is a small instrument made of a metal rod bent into a triangle shape that is open at one corner. While small, its sound is distinct, with multiple overtones and nonharmonic resonance. But what causes the surprisingly powerful sound?
“The triangle instrument produces enchanting and beautiful tones, raising deep and profound questions about the connection between music and physics,” author Risako Tanigawa said. “Optical sound measurement has…click to read more
Singing in the Rain: Why the Bundengan Sounds Better Wet #Acoustics23
Traditional Indonesian instrument made with bamboo and used by duck herders performs best in the rain.
SYDNEY, Dec. 6, 2023 – A bundengan wears many hats – and is one too. This portable shelter woven from bamboo has protected Indonesian duck herders from the sun and rain for centuries. Able to comfortably balance on the wearer’s head, a bundengan is equipped with a visor that curves around the side to meet at a long back. A more surprising, but no less practical, feature is the collection of strings and bamboo bars added in to produce music. Duck herders fill the hours spent tending to ducks sitting underneath their outfitted shelter, playing their shield as an instrument.
Over the years, bundengan musicians learned that their bamboo music-maker sounds better when played in the rain. Gea Oswah Fatah Parikesit and their team at Universitas Gadjah Mada investigated the physics behind this phenomenon and are presenting their work on the water-dependent acoustic properties of the bundengan Dec. 6 at 10:40 a.m. Australian Eastern Daylight Time, as part of Acoustics 2023, running Dec. 4-8 at the International Convention Centre Sydney.
The bundengan is constructed by weaving bamboo splits, which are covered by overlapping bamboo culm sheaths with ropes to secure everything in place.
“Our team discovered that the key to the sound quality is in the bamboo culm sheaths,” said Parikesit. “To understand the physics of the sheaths, we first had to understand its biological context. When the sheaths were still attached at the bamboo stem, they gradually change shape: First, they are curled because they need to protect the younger parts of the stem, but afterward, they have a more planar shape because they no longer need to protect the older part of the stem.”
When wet, the culm sheaths seek to return to their curled form, but tied down in their planar formation, they instead press into each other. The resulting tension allows the sheaths to vibrate together.
Parikesit will continue investigating the physics of the bamboo culm to develop new musical instruments that, like the bundengan, perform best when wet.
“As an Indonesian, I have extra motivation because the bundengan is a piece of our cultural heritage,” said Parikesit. “I am trying my best to support the conservation and documentation of the bundengan and other Indonesian endangered instruments.”
Image of a bundengan, a portable shelter woven from bamboo, which is worn by Indonesian duck herders who often outfit it to double as a musical instrument. Credit: Gea Oswah Fatah Parikesit
———————– 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.
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/
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.”
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.
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/
Central Washington University, Department of Physics, Ellensburg, WA, 98926, United States
Seth Lowery
Ph.D. candidate, University of Texas
Dept. of Mechanical Engineering
Austin, TX
Popular version of 4pMU3 – An experiment to measure changes in violin instrument response due to playing-in
Presented at the 185th ASA Meeting
Read the abstract at https://doi.org/10.1121/10.0023547
Please keep in mind that the research described in this Lay Language Paper may not have yet been peer reviewed.
How is a violin like a pair of hiking boots? Many violinists would respond “They both improve with use.” Just as boots need to be “broken in” by being worn several times to make them more supple, many musicians believe that a new violin, cello, or guitar, needs to be “played in” for a period of time, typically months, in order to fully develop its acoustic properties. There is even a commercial product, the Tone-Rite, that is marketed as a way to accelerate the playing-in process, with the claim of dramatically increasing “resonance, balance, and range,” and some builders of stringed instruments, known as luthiers, provide a service of pre-playing-in their instruments, using their own methods of mechanical stimulus, prior to selling them. But do we know if violins actually improve with use?
We tested the hypothesis that putting vibrational energy into a violin will, over time, change how the violin body responds to the vibration of the strings, which is measured as the frequency response. We used three violins in our experiment: one was left alone, serving as a control, while the two test violins were “played” by applying mechanical vibrations directly to the bridge. One of the mechanical sources was the Tone Rite, the other was a shaker driven with a signal created from a Vivaldi violin concerto as shown in the video below. The total time of vibration exceeded 1600 hours, equivalent to ten months of being played six hours per day.
Approximately once per week, we measured the frequency response of all three violins using two standard methods: bridge admittance, which characterizes the vibration of the violin body, and acoustic radiativity, which is based on the sound radiated by the violin. The measurement set up is illustrated in Figure 1.
Figure 1: Measuring the frequency response of a violin in an anechoic chamber.
Having a control violin allowed us to account for factors not associated with playing-in, such as fluctuating environmental conditions or simple aging, that might affect the frequency response. If mechanical vibrations had the hypothesized effect of physically altering the violin body, such as creating microcracks in the wood, glue, or varnish, and if the result were an increase in “resonance, balance, and range”, then we would expect a noticeable and cumulative change in the frequency response of the test violins compared to the control violin.
We did not observe any changes in the frequency responses of the violins that correlate with the amount of vibration. In Figure 2a, we plot a normalized difference in the bridge admittance between the two test violins and the control violin; Figure 2b shows a similar plot for the acoustic radiativity.
In both plots, we see no evidence that the difference between the test violins and the control violin increases with more vibration; instead we see random fluctuations that can be attributed to the slightly different experimental conditions of each measurement. This applies to both the Tone-Rite, which vibrates primarily with the 60 Hz frequency of the electric power it is plugged into, and the shaker, which provided the same frequencies that a violinist practicing her instrument would create.
Our conclusion is that long term vibrational stimulus of a violin, whether achieved mechanically or by actual playing, does not produce a physical change in the violin body that could affect its tonal characteristics.
This presentation examines how electric guitar effects helped pave the road to modern rock and roll music. Distortion effects provide sustain for the guitar similar to other core-ensemble instruments like the violin and piano in classical music. Distortion can also make the sound brighter to heighten the often aggressive sound of rock music. Other effects, like the chorus, phaser, and flanger, can help make the guitar sound much wider, something we are also used to listening to with classical orchestras. To some extent, electrical guitar effects substituted for and expanded upon the room reverberation that typically accompanies classical music, and they were instrumental in producing stereo Rock ‘n’ Roll records that provide spatial width, something old mono records do not provide. While often having favorable sound-color characteristics, the sound of mono recordings sits static in between both ears when listening through headphones or earbuds. This phenomenon, which is called inside-the-head locatedness, is not apparent when listening through a loudspeaker. Without electric sound effects, the electric guitar would not have become the distinctive instrument that Jimi Hendrix, Link Wray, Chuck Berry, and others defined.
Figure 1: Schematic depicting the stereo image (left/right balance) for examplary stereo recordings. Left: In Jazz albums like Miles Davis’ Kind of Blue, placing instruments to the left, center, or right worked well because of the transparent sound ideal of the genre; Center: Early rock/pop songs like the Beatles’ “Helter Skelter” used the same approach with less success; Right: Electronic effects later made it possible to widene the instrument sounds like it is the case for Nirvana’s “Smells like teen spirit” — reflecting the genre’s sound ideal to perceptually fuse sounds together.
A brief survey was conducted to investigate the extent to which electrical sound effects provide a desirable guitar sound beyond the sustain and spatial qualities these effects can provide. The outcome for a group of 21 participants (guitarist and non-guitarists) suggests that listeners have their distinct preferences when listening to a blues solo. It appears that they prefer some but not all distortion effects over a clean, non-distorted sound.
Figure 2: Guitar effects used in the listening survey
Figure 3: Results of the listening survey. The average preference over 21 listener is shown as a function of 10 different guitar distortion effects that were used in the survey. Three percpetually distinct groups were found. Two effects rated significantly higher than the other eight, and one effect was rated significantly lower than all other ones. The clean (no effect) condition was in the center group, so dependent on the type of distortion, the effect can make the guitar sound better or worth.
Figure 1: Measuring the frequency response of a violin in an anechoic chamber.
