LEGO Down! Focused Vibrations Knock Over Minifigures

Time reversal technique focuses wave energy to knock over minifigure targets in museum demonstration

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

SEATTLE, December 2, 2021 — A tabletop covered in miniature LEGO minifigures. There is a whooshing sound, a pause, and then a single minifigure in the center of the table topples over, leaving the remaining minifigures standing.

Brian Anderson, of Brigham Young University, will discuss how this is achieved in his presentation at the 181st Meeting of the Acoustical Society of America, “Knocking over LEGO minifigures with time reversal focused vibrations: Understanding the physics and developing a museum demonstration.” The session will take place on Dec. 2 at 5:15 p.m. Eastern U.S. in the Elwha B Room, as part of the conference running from Nov. 29 to Dec. 3 at the Hyatt Regency Seattle.

Anderson and his team use speaker shakers to generate vibrations in a plate. They place LEGO minifigures on the plate, choose a target, and measure the impulse response between each shaker and the target location. Playing that very response from the shakers, but reversed in time, creates sound waves that constructively interfere at the target minifigure. The focused energy knocks over the single LEGO minifig without disrupting the surrounding minifigs.

This demonstration was transformed into a two-player game for a museum exhibit in a wave propagation museum hosted by ETH Zurich in Switzerland. Two visitors take turns focusing vibrations and attempting to knock over the LEGO minifigures on the other team.

The technique also has numerous applications beyond LEGO, and Anderson said it shows the power of focused vibrations.

“Time reversal has been used to focus sound in the body that is intense enough to destroy kidney stones or brain tumors without requiring surgery,” Anderson said. “I have used time reversal to locate cracks or defects with ultrasound in metal structures, such as storage canisters for spent nuclear fuel. Time reversal can also be used to locate and characterize earthquakes or locate gun shots within an urban city environment.”

———————– MORE MEETING INFORMATION ———————–
USEFUL LINKS
Main meeting website: https://acousticalsociety.org/asa-meetings/
Technical program: https://eventpilotadmin.com/web/planner.php?id=ASAFALL21
Press Room: https://acoustics.org/world-wide-press-room/

WORLDWIDE PRESS ROOM
In the coming weeks, ASA’s Worldwide Press Room will be updated with additional tips on dozens of newsworthy stories and with lay language papers, which are 300 to 500 word summaries of presentations written by scientists for a general audience and accompanied by photos, audio and video. You can visit the site during the meeting at https://acoustics.org/world-wide-press-room/.

PRESS REGISTRATION
We will grant free registration to credentialed journalists and professional freelance journalists. If you are a reporter and would like to attend, contact AIP Media Services at media@aip.org. For urgent requests, staff at media@aip.org 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/.

Killer Whales Lingering in Newly Melted Arctic Ocean

Melting ice opens new predation ground for killer whales as they spend more time in previously neglected territory

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

SEATTLE, December 2, 2021 – Killer whales are intelligent, adaptive predators, often teaming up to take down larger prey. Continuous reduction in sea ice in the Arctic Ocean is opening areas to increased killer whale dwelling and predation, potentially creating an ecological imbalance.

During the 181st Meeting of the Acoustical Society of America, which will be held Nov. 29 to Dec. 3, Brynn Kimber, from the University of Washington, will discuss how killer whales have spent more time than previously recorded in the Arctic, following the decrease in sea ice. The talk, “Tracking killer whale movements in the Alaskan Artic relative to a loss of sea ice,” will take place Thursday, Dec. 2, at 5:35 p.m. Eastern U.S.

Killer whales will often traverse to different areas to target varieties of prey. In a study including eight years of passive acoustic data, Kimber and their team monitored killer whale movements using acoustic tools, finding killer whales are spending more time than previously recorded in the Arctic Ocean, despite risks of ice entrapment there. Their readings indicate this change is directly following the decrease in sea ice in the area.

“It’s not necessarily that killer whales haven’t been reported in these areas before, but that they appear to be remaining in the area for longer periods of time,” said Kimber. “This is likely in response to a longer open water season.”

The reduction in sea ice may have opened new hunting opportunities for killer whales if certain species of prey are unable to use the ice to avoid the highly adaptive predator. For example, the endangered bowhead whale is vulnerable to predation by killer whales, likely to increase due to longer open water seasons.

“Although there is high spatial and interannual variability, the September Arctic sea ice minimum is declining at an average rate of 13% per decade, when compared to values from 1981 to 2010,” said Kimber. “Killer whales are being observed in the Chukchi Sea (in the Arctic Ocean) in months that were historically ice covered and more consistently throughout the summer.”

———————– MORE MEETING INFORMATION ———————–
USEFUL LINKS
Main meeting website: https://acousticalsociety.org/asa-meetings/
Technical program: https://eventpilotadmin.com/web/planner.php?id=ASAFALL21
Press Room: https://acoustics.org/world-wide-press-room/

WORLDWIDE PRESS ROOM
In the coming weeks, ASA’s Worldwide Press Room will be updated with additional tips on dozens of newsworthy stories and with lay language papers, which are 300 to 500 word summaries of presentations written by scientists for a general audience and accompanied by photos, audio and video. You can visit the site during the meeting at https://acoustics.org/world-wide-press-room/.

PRESS REGISTRATION
We will grant free registration to credentialed journalists and professional freelance journalists. If you are a reporter and would like to attend, contact AIP Media Services at media@aip.org. For urgent requests, staff at media@aip.org 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/.

Filtering Unwanted Sounds from Baby Monitors

Ideal baby monitors alert parents to infant cries, not irrelevant background noise

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

SEATTLE, December 2, 2021 – New parents often keep a constant ear on their children, listening for any signs of distress as their baby sleeps. Baby monitors make that possible, but they can also inundate parents with annoying background audio.

In his presentation, “Open-Source Baby Monitor,” TJ Flynn, of Johns Hopkins University, will discuss his team’s effort to develop and test a smart baby monitor. The talk, on Dec. 2 at 1:25 p.m. Eastern U.S. in Room Columbia C, is part of the 181st Meeting of the Acoustical Society of America, taking place Nov. 29 to Dec. 3 at the Hyatt Regency Seattle.

Flynn, Shane Lani, and their team aim to create an ideal baby monitor that alerts parents when their baby needs attention but does not transmit or amplify sound from other sources. The project uses open source audio processing hardware, originally intended for hearing aids, to filter out unwanted noises. These extra sounds might lead parents to turn down their baby monitor volume and potentially miss infant cries.

“Three of the study authors, including myself, are parents to new babies,” said Lani, a researcher from Johns Hopkins University. “While not directly applicable to every home, my house is situated next to a large state road and in the flight path for landing planes depending on the wind conditions. Due to these factors, loud motorcycles tearing down the highway and low flying planes have historically been a big culprit in setting off the monitor.”

The researchers found baby cries have a fundamental frequency in the range of 400 to 600 hertz, with plenty of harmonics that extend up to 10 kilohertz. They plan to keep the whole frequency range in mind as they explore signal processing options.

Their device is of comparable size to commercial baby monitors, and they are currently testing its performance.

———————– MORE MEETING INFORMATION ———————–
USEFUL LINKS
Main meeting website: https://acousticalsociety.org/asa-meetings/
Technical program: https://eventpilotadmin.com/web/planner.php?id=ASAFALL21
Press Room: https://acoustics.org/world-wide-press-room/

WORLDWIDE PRESS ROOM
In the coming weeks, ASA’s Worldwide Press Room will be updated with additional tips on dozens of newsworthy stories and with lay language papers, which are 300 to 500 word summaries of presentations written by scientists for a general audience and accompanied by photos, audio and video. You can visit the site during the meeting at https://acoustics.org/world-wide-press-room/.

PRESS REGISTRATION
We will grant free registration to credentialed journalists and professional freelance journalists. If you are a reporter and would like to attend, contact AIP Media Services at media@aip.org. For urgent requests, staff at media@aip.org 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/.

Sounding Off on Seattle Space Needle Renovation

Acoustic designers consulted to prevent noisy viewing deck, mechanics

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

SEATTLE, December 2, 2021 – The Seattle Space Needle, a city landmark for nearly 60 years, recently underwent a renovation to enhance the visitor experience. Acoustic designers were tasked with ensuring that the new design is a quiet one.

During the 181st Meeting of the Acoustical Society of America, which will be held Nov. 29 to Dec. 3, Daniel Bruck and Jaimie Penzell, from BRC Acoustics, will discuss how the Seattle Space Needle renovation incorporated acoustic designs targeted toward limiting unnecessary sound transmission. The talk, “The Seattle Space Needle renovation: Acoustical design considerations and challenges at 600 feet above ground level,” will take place Thursday, Dec. 2, at 12:55 p.m. Eastern U.S.

The Seattle Space Needle is one of the most recognizable landmarks in North America, having had 60 million visitors since it opened in 1962. In late 2017, a renovation project titled “The Century Project” began, developing the tower’s internal structure, while expanding and improving its views.

Bruck and his team developed the acoustical design criteria for the renovation project, enhancing future visitor experience.

The needle revamp has an improved observation deck with 360 degrees of uninterrupted views of Seattle and the surrounding area, as well as The Loupe – the world’s first and only rotating glass floor restaurant.

“Acoustical materials were selected to complement the architectural concept for the spaces and provide effective reverberant sound control,” said Bruck. “Particular areas for design were the observation levels, which was noisy during high visitor periods, and the restaurant. Sound isolation between the two was also an important component.”

Mechanical system noise control was an essential consideration, as the newly installed revolving floor mechanism requires 12 motors to operate 37 tons of weight.

“The original building from 1962 was not designed for modern equipment, and there was absolutely no room to expand the footprint of the mechanical rooms,” said Bruck. “The machinery and system were completely redesigned to provide an innovative approach to moving the rotating floor reliably into the future.”

———————– MORE MEETING INFORMATION ———————–
USEFUL LINKS
Main meeting website: https://acousticalsociety.org/asa-meetings/
Technical program: https://eventpilotadmin.com/web/planner.php?id=ASAFALL21
Press Room: https://acoustics.org/world-wide-press-room/

WORLDWIDE PRESS ROOM
In the coming weeks, ASA’s Worldwide Press Room will be updated with additional tips on dozens of newsworthy stories and with lay language papers, which are 300 to 500 word summaries of presentations written by scientists for a general audience and accompanied by photos, audio and video. You can visit the site during the meeting at https://acoustics.org/world-wide-press-room/.

PRESS REGISTRATION
We will grant free registration to credentialed journalists and professional freelance journalists. If you are a reporter and would like to attend, contact AIP Media Services at media@aip.org. For urgent requests, staff at media@aip.org 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/.

Food Paradox Answer Shows How Ocean Life Survives

Acoustic tools reveal hotspots of ocean life in scattered places

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

SEATTLE, December 1, 2021 – Ocean predators cannot survive on average concentrations of food found in the water. Instead, they survive by exploiting small patches of food-rich areas peppered throughout the world’s waterways.

During the 181st Meeting of the Acoustical Society of America, which will be held Nov. 29 to Dec. 3, Kelly Benoit-Bird, from the Monterey Bay Aquarium Research Institute, will discuss how sonar or active acoustics can be used to interpret and indicate biological hotspots of ocean life. The talk, “A Sound Resolution to the Food Paradox in the Sea,” will take place Wednesday, Dec. 1, at 4:05 p.m. Eastern U.S.

Using active acoustics, where a sound pulse is created and resulting echoes are interpreted, the researchers found the ocean is widely populated with narrow hotspots of activity. Traditionally, these hotspots are missed with conventional sampling tools, but locating them can provide dynamic layered maps of ocean life.

“We’re using systems much like those used to find the depth of the ocean, but instead of interpreting echoes from the seafloor, we’re using more sensitive systems that allow us to map layers of life in the water,” said Benoit-Bird. “What we’ve found is that animals of all different sizes, from millimeter long plankton to large predators, are unevenly distributed, and this variation is really important to how life in the ocean functions.”

The findings signify ocean food and biota as patchy, varying with depth and location, suggesting animals must find and exploit small scale aggregations of resources.

The Lasker food paradox proposed in the 1970s found laboratory animals fed the average concentration of ocean food did not survive, but ocean-dwelling animals in the wild did. The paradox is reconciled by Benoit-Bird’s findings, demonstrating animals do not survive on average food concentrations but are well-adapted to locating and capitalizing on patches of resources, and reducing their total energy expenditure to hunt.
“For example, if a bucket’s worth of popcorn was spread out evenly throughout the volume of a room, and you had to fly around to capture each kernel, you would spend a lot of energy searching and it would be hard to get enough to be full,” Benoit-Bird said. “If instead, the popcorn was all grouped together, the popcorn would be a much more satisfying snack. The amount of popcorn is the same but changing how it is grouped determines whether you end up with a full belly.

“Acoustic tools provide the high spatial resolution and long duration sampling to explore the processes that drive organismal interactions in the ocean. We must understand not only how many animals are in the ocean, but how they are distributed, if we are to effectively manage our living marine resources.”

———————– MORE MEETING INFORMATION ———————–
USEFUL LINKS
Main meeting website: https://acousticalsociety.org/asa-meetings/
Technical program: https://eventpilotadmin.com/web/planner.php?id=ASAFALL21
Press Room: https://acoustics.org/world-wide-press-room/

WORLDWIDE PRESS ROOM
In the coming weeks, ASA’s Worldwide Press Room will be updated with additional tips on dozens of newsworthy stories and with lay language papers, which are 300 to 500 word summaries of presentations written by scientists for a general audience and accompanied by photos, audio and video. You can visit the site during the meeting at https://acoustics.org/world-wide-press-room/.

PRESS REGISTRATION
We will grant free registration to credentialed journalists and professional freelance journalists. If you are a reporter and would like to attend, contact AIP Media Services at media@aip.org. For urgent requests, staff at media@aip.org 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/.

Sing On: Certain Facemasks Don’t Hinder Vocalists

Masks designed for singers prevent COVID-19 transmission, most voice distortion

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

SEATTLE, December 1, 2021 – When singers generate beautiful notes, they can also release harmful particles like the coronavirus. Wearing a mask prevents virus transmission, but it also affects the sound.

Thomas Moore, from Rollins College, will discuss his observations of a professional soprano singing with and without six types of masks at the 181st Meeting of the Acoustical Society of America, which will be held Nov. 29 to Dec. 3. The session, “Aerosol propagation and acoustic effects while singing with a face mask,” will take place on Dec. 1 at 12:40 p.m. Eastern U.S. in Room 302 of the Hyatt Regency Seattle as part of a session on making music during a pandemic.

Moore found masks effectively block aerosols, forcing the breath to exit at the sides. From there, the aerosols travel upwards, rising with the upward flow of body heat from the singer. The dispersal of breath likely dilutes the virus and prevents the spread of COVID-19.

At low frequencies, masks reduced volume but did not have other effects on the singing. However, masks did reduce the power of higher frequencies, which made the enunciation of words less clear and altered the timbre. Masks had no effect on the pitch.

One of the masks tested, a singer’s mask, was designed specifically with singers in mind. All six masks blocked the forward flow of breath, but the singer’s mask did so with the least change in sound.

“A normal cloth mask can reduce the high frequencies by as much as 10 times, but a singer’s mask will reduce them by a factor of less than 2,” said Moore.

Diluting virus-causing aerosols is key to reducing infection and the spread of the COVID-19 virus. Although Moore found the breath still escaped the sides of the masks, its rise into the air and subsequent dispersal lowers the risk compared to singing without a mask. He said this emphasizes how good air flow in a room is critical for preventing viral risk.

———————– MORE MEETING INFORMATION ———————–
USEFUL LINKS
Main meeting website: https://acousticalsociety.org/asa-meetings/
Technical program: https://eventpilotadmin.com/web/planner.php?id=ASAFALL21
Press Room: https://acoustics.org/world-wide-press-room/

WORLDWIDE PRESS ROOM
In the coming weeks, ASA’s Worldwide Press Room will be updated with additional tips on dozens of newsworthy stories and with lay language papers, which are 300 to 500 word summaries of presentations written by scientists for a general audience and accompanied by photos, audio and video. You can visit the site during the meeting at https://acoustics.org/world-wide-press-room/.

PRESS REGISTRATION
We will grant free registration to credentialed journalists and professional freelance journalists. If you are a reporter and would like to attend, contact AIP Media Services at media@aip.org. For urgent requests, staff at media@aip.org 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/.