Maria Paula Rey Baquero – rey_m@javeriana.edu.co Instagram: @mariapaulareyb Pontificia Universidad Javeriana Fundación Macuáticos Colombia Bogotá Colombia
Additional Authors: Kerri D. Seger Camilo Andrés Correa Ayram Natalia Botero Acosta Maria Angela Echeverry-Galvis
Project Ports, Humpbacks y Sound In Colombia – @physicolombia Fundación Macuaticos Colombia – @macuaticos Semillero Aquasistemas – @aquasistemaspuj
Popular version of 4aAB5 – Modeling for acoustical corridors in patchy reef habitats of the Gulf of Tribugá, Colombia Presented at the 188th ASA Meeting Read the abstract at https://doi.org/10.1121/10.0037990
–The research described in this Acoustics Lay Language Paper may not have yet been peer reviewed–
Sound plays a fundamental role in marine ecosystems, functioning as an invisible network of “pathways” or corridors that connect habitat patches and enable critical behaviors like migration, communication, and reproduction. In Colombia’s northern Pacific, one of the most biodiverse regions, the Gulf of Tribugá stands out for its pristine soundscape, dominated by the sounds of marine life. Designated a UNESCO Biosphere Reserve and a “Hope Spot” for conservation, this area serves as a vital nursery for humpback whales and supports local livelihoods through ecotourism and artisanal fishing. However, increasing human activities, including boat traffic and climate change, threaten these acoustic habitats, prompting researcher on how sound influences ecological connectivity—the lifeline for marine species’ movement and survival.
This study in Colombia’s Gulf of Tribugá mapped how ocean sounds connect marine life by integrating acoustic data with ecological modeling. Researchers analyzed how sound travels through the marine environment, finding that humpback whale songs (300 Hz) create natural acoustical corridors along coastal areas and rocky islands (‘riscales’). These pathways, though occasionally interrupted by depth variations, appear crucial for whale communication, navigation, and maintaining social connections during migration. In contrast, fish calls (100 Hz) showed no detectable sound corridors, suggesting fish may depend less on acoustic signals or use alternative navigation cues like wave noise when moving between habitats.
Photographs of some of the recorded fish species. Source: Author
The research underscores that acoustical connectivity is species-specific. While humpback whales may depend on sound corridors and prioritize long-distance communication, fish may prioritize short-range communication or other environmental signals. At any distance, noise pollution disrupts these systems universally: The bubbling/popping sounds created by spinning boat propellers, for instance, generate frequencies that can covers up the whale songs and fish calls and degrade habitat quality, even if fish are less affected over the same distances that whales are. Background noise shrinks and breaks up the underwater corridors that marine animals use to communicate and navigate, harming their underwater sound habitat.
Figure 1. Received sound levels when emitted by singers (a) without noise and (b) with background noise, at a grain size of 2 Φ. The left column shows conditions without background noise, and the right column shows conditions with noise. Sound intensities most likely to be heard by a humpback whale at 200 Hz are shown in green, less likely sounds in orange, and inaudible sounds in black. Source: Author
Noise pollution alters behaviors and acoustic corridors humpback whales rely on for communication and navigation in Colombia’s Pacific waters. Notably, the fish species studied showed no sound-dependent movement, suggesting their reliance on other cues. The study advocates for sound-inclusive conservation, proposing that acoustic data (more easily gathered today via satellites, field recordings, and public databases) should join traditional metrics like currents or temperature in marine management. Protecting acoustic corridors could become as vital as safeguarding breeding grounds, especially in biodiverse hubs like Tribugá.
This work marks a first step towards integrated acoustical-ecological models, offering tools to quantify noise impacts and design smarter protections. Future research could refine species-specific sound thresholds or expand to deeper oceanic areas. For now, the message is preserving marine ecosystems requires listening, not just looking. Combining efforts to lessen human noise by using mapped soundscapes to target critical corridors could help in the conservation of marine species.
Domenico De Salvio – domenico.desalvio2@unibo.it Instagram: @midrashdds Department of Industrial Engineering (DIN) University of Bologna Bologna, Bologna 40136 Italy
Massimo Garai Department of Industrial Engineering (DIN) University of Bologna Bologna, Bologna 40136 Italy
Popular version of 3pNS3 – Metamaterials application on low-height noise barrier for railways: challenges of real-world scenarios Presented at the 188th ASA Meeting Read the abstract at https://doi.org/10.1121/10.0037929
–The research described in this Acoustics Lay Language Paper may not have yet been peer reviewed–
If you’ve ever lived near a train line, you know the roar of passing cars can be more than annoying — it can hurt your health. A primary source of this noise comes from transportation; among them, railway lines, having a high density in Europe, can be particularly disturbing for nearby residents. The traditional high noise barriers can help, but they aren’t always practical in urban areas. Low-height noise barriers (LHNBs), typically less than 1 meter high, can be a good alternative. These barriers work well because they can be placed very close to the source of the noise, such as where train wheels interact with the rails, as shown in Figure 1.
Figure 1. A low-height noise barrier is placed next to the railway. Image courtesy of Kraiburg Strail®.
However, for these low barriers to work best, their surface needs to be good at absorbing sound (see Figure 2). Here, acoustic metamaterials can play a key role. These artificial structures have unique properties that natural materials lack, enabling them to absorb sound in ways that conventional materials cannot. Their functionality relies on their geometric configuration rather than solely on the raw materials used, enabling them to be made from weather- and dust-resistant materials.
Figure 2. The effectiveness of an LHNB. The colors represent sound pressure level: red indicates the highest noise levels, while blue shows the lowest. On the left, the noise generated by the wheel-rail interaction. In the middle, the effectiveness of a generic LHNB is shown. On the right, the noise reduction achieved by an optimized sound-absorbing LHNB. The less red there is, the more effective the LHNB is.
This study is part of the European project LIFE SILENT and examines the integration of metamaterials into a specific type of LHNB. It employs two types of acoustic resonators designed within the constraints of a real-world scenario: Neck Embedded Helmholtz Resonators (NEHRs) and Fabry-Pérot (FP) channels. Combining these resonators enables the LHNB to mitigate railway noise.
Designing these complex structures requires a thorough process. The optimal geometry of the metamaterial has been studied through a combination of complex simulations and nature-inspired algorithms. Specifically, the geometry was optimized using a computational technique called “particle swarm” inspired by the social behavior of flocks of birds and schools of fish.
Prototypes of the metamaterial units were 3D printed in plastic because of the need for customization and precision (see Figure 3). Once the efficiency of the metamaterial is tested, serial production of the optimized geometry can also be achieved through traditional industrial molding techniques, thus, in real-world scenarios.
Figure 3. Example of 3D printed metamaterial NEHRs (on the left) and FP (on the right), the units that compose the sound-absorbing LHNB surface.
This work demonstrates how metamaterial engineering can be applied to everyday situations. The study tackles practical limitations and constraints, the need for durability against outdoor conditions, and the challenges of manufacturing complex structures. The research outlines the essential steps to transition from a lab idea to a potentially mass-produced solution against noise pollution by developing a focused design, creating physical prototypes, and conducting tests. While recognizing challenges like manufacturing accuracy and the impact of real-world conditions, the project emphasizes that acoustic metamaterials can be designed to be robust and effective for public infrastructure, paving the way for their practical use for a better daily life.
Quiet Communities, Scientific Advisory Board, The Robert and Nalini Lasiewicz Foundation, BOISE, ID, 83703-1000, United States
Daniel Fink – DJFink@thequietcoalition.org
Program Chair, The Quiet Coalition
A program of Quiet Communities, Inc.
60 Thoreau Street Suite 261
Concord, MA 01742
Popular version of 4aPP1 – Pickleball noise – A qualitative description of the psychological and physiological effects on nearby residents
Presented at the 188th ASA Meeting
Read the abstract at https://doi.org/10.1121/10.0038039
–The research described in this Acoustics Lay Language Paper may not have yet been peer reviewed–
New research shows that pickleball noise appears to raise major health concerns for residents living near courts. Pickleball is a racquet sport like tennis, but is played on smaller courts with hard wood or fiberglass paddles and hard plastic balls similar to whiffle balls. Instead of the softer “ping” heard during tennis, pickleball play makes a piercing “pop” sound. Pickleball started increasing in popularity during Covid, and many residents living near courts have now had several years of daily exposure to the popping noise.
How does pickleball noise affect the neighbors? Image source: Nicholas Klein, Istock photo 1746673904, 2023
Our study found that disrupted sleep, cardiac, and neurologic issues were the most common self-reported physical symptoms from nearby neighbors as shown in Figure 1. Hearing phantom pops appears to be a new type of phenomenon that can’t be completely explained yet, but may represent changes in brain processing systems.
Figure 1: Self-reported physical symptoms from pickleball noise exposure.
Self-reported psychological symptoms included mental health problems, mentions of trauma, and “red flag” complaints including severe distress, mention of torture, and suicidal thoughts as shown in Figure 2. An example of a comment that was classified as “severe distress” is: “No one would choose to live this way. It is physically and emotionally debilitating”.
Figure 2: Self-reported psychological symptoms from pickleball noise exposure.
Why do those living near pickleball courts feel this way?
The piercing “pop” comes from a sudden, loud burst of sound called impulse noise. Impulse noise is characterized by short duration with a sharp rise and decrease, as shown below in Figure 3.
Figure 3: Pickleball noise sound pressure trace. Image courtesy of Lance Willis, Spenderian and Willis, Tucson, AZ.
Listen to this audio below to hear the sound generated by 4 pickleball courts.
An acoustic study of one neighbor’s experience found up to 2800 pickleball pops per hour, for a total of 21,208 pops in one day as shown in Figure 4. That’s a lot of disruptive impulse noise to endure. And to make it even worse, the frequency of the “popping” sound (about 1200 Hertz) is the same as back up alarms for vehicles.
Figure 4: One day, 4 courts, hourly distribution of 21,208 total pops. Image courtesy of Noise Net Operations US, Inc.
It’s not unusual for those living near pickleball courts to be exposed to this repetitive impulse noise more than 90 hours/week. That might be more than 100,000 pickleball pops a week! Figure 5 demonstrates a day for busy courts open from 8 a.m. until 9 p.m.
Figure 5: A typical day of pickleball noise exposure for a neighbor near busy courts.
While some workplace studies have examined impulse noise and hearing loss, our study is the first to explore its health effects on the general public. Long-term exposure to impulse noise wasn’t a public concern until pickleball courts were built near homes. In some cases, the popping is even heard inside people’s homes.
We used a research method called content analysis to analyze public comments in news reports, legal filings and social media, spotting early trends by grouping and counting similar comments. While not definitive, this method helps identify problems, guide research, and spark discussion.
Local noise ordinances often focus on average sound levels (decibels) and don’t regulate repetitive impulse noise like pickleball. Unfortunately, most noise studies don’t consider all the factors that affect how people actually perceive such noise, especially the repetitive impulse noise hours a day from pickleball play. As pickleball noise expert and referee Bob Unetich told NPR in 2023, “You can’t take pop, pop, pop for 12 hours a day every day and remain sane.”
We need more research on how long-term impulse noise affects the health of people living near pickleball courts. Future studies could look at what makes pickleball noise unique, how this kind of noise impacts people’s minds and bodies, how far courts should be from homes, and how well different noise-reducing methods work.
So far, we aren’t aware of any courts within 100 feet of homes that have been successfully quieted. Until more is known, we recommend that courts not be placed within 100 feet of homes and that courts within 1,000 feet of homes receive close attention. Sound evaluations by engineers should look at more than just how loud the sound is. All the factors that affect how humans perceive sound should be considered.
There is no doubt that pickleball is lots of fun for those who play, but it raises major health concerns for those living near the courts.
Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu, -, 300, Taiwan
Popular version of 1aSP2 – Target-Direction Sound Extraction Using a Hybrid DSP/Deep Learning Approach
Presented at the 187th ASA Meeting
Read the abstract at https://doi.org/10.1121/10.0034980
–The research described in this Acoustics Lay Language Paper may not have yet been peer reviewed–
In a noisy world, capturing clear audio from specific directions can be a game-changer. Imagine a system that can zero in on a target sound, even amid background noise. This is the goal of Target Directional Sound Extraction (TDSE), a process designed to isolate sounds from a particular direction, while filtering out unwanted noise.
Our team has developed an innovative TDSE system that combines Digital Signal Processing (DSP) and deep learning. Traditional sound extraction relies on signal processing, but it struggles when multiple sounds come from various directions or when using fewer microphones. Deep learning can help, but it sometimes results in distorted audio. By integrating DSP-based spatial filtering with a deep neural network (DNN), our system extracts clear target audio with minimal interference, even with limited microphones.
The system relies on spatial filtering techniques like beamforming and blocking. Beamforming serves as a signal estimator, enhancing sounds from the target direction, while blocking acts as a noise estimator, suppressing sounds from the target direction and leaving other unwanted noises intact. Using a deep learning model, our system processes spatial features and sound embeddings (unique characteristics of the target sound), yielding clear, isolated audio. In our tests, this method improved sound quality by 3-9 dB and performed well with different microphone setups, even those not used during training.
TDSE could transform various industries, from virtual meetings to entertainment, by enhancing audio clarity in real time. Our system’s design offers flexibility, making it adaptable for real-world applications where clear directional audio is crucial.
This approach is an exciting step toward more robust, adaptive audio processing systems, allowing users to capture target sounds even in challenging environments.
Grant W. Hart – grant_hart@byu.edu
Brigham Young University
Provo, UT 84602
United States
Kent Gee (@KentLGee on X)
Eric Hintz
Giovanna Nuccitelli
Trevor Mahlmann (@TrevorMahlmann on X)
Popular version of 1pNSa8 – A photographic analysis of Mach wave radiation from a rocket plume
Presented at the 186th ASA Meeting
Read the abstract at https://doi.org/10.1121/10.0026810
The rumble of a large rocket launching is one of the loudest non-explosive sounds that mankind has ever made. Where does that sound come from? Surprisingly, it doesn’t come from the rocket itself, or even the exhaust nozzle, but rather from the plume of exhaust that shoots out of the back. The plume is supersonic when it comes out of the rocket, and it emits sound as it slows down in the atmosphere.
This process was visualized in some recent pictures taken by Trevor Mahlmann of a Falcon 9 launch from Cape Canaveral. The launch was just after dawn, and Mahlmann took a series of striking pictures as the rocket passed in front of the sun. Two of those pictures are shown below. If you look at the edge of the sun in the later picture you can see distortions caused by the intense sound waves coming from the rocket.
Recognizing the possibility of gaining more information from these pictures, researchers at Brigham Young University got permission from Mr. Mahlmann to further analyze them. The third picture below shows a portion of the difference between the first two pictures. The colors have been modified to show the sound waves more clearly. The waves clearly are coming from a region far down the plume of the rocket, rather than the nozzle of the rocket. The source was typically about 10-25 times the diameter of the rocket down the plume.
The sound is also directional – it doesn’t go out evenly in all directions, but rather goes out most strongly at about 20-30 degrees below the horizontal. Most rockets sound loudest to people watching the launch when they are 20-30 degrees above the ground. This is all consistent with the models of the sound being produced by the processes that slow down the exhaust from supersonic speeds. A good introduction to rocket noise is found in a recent article in Physics Today.
The researchers first had to line up the images so that the sun was in the same place in each frame. They were then able to subtract the later image from the first one to get the difference and leave just the distortions caused by the waves in the second image. To find the source of the waves, it was necessary to draw a line backward from the wave’s image and find where it met the rocket’s path across the Sun. Since it took time for the wave to get from the source to where it was observed, they had to find where the rocket was at the time the sound wave was given off. They did this by finding how far the sound had traveled and used the speed of sound to find the time it took to get there. With that information the researchers could find the position of the source and the direction of the wave.
Figure 3. A portion of the difference between the two previous figures, showing the enhanced sound waves. The bottom of the rocket is at the top of the image. Image adapted from Hart et al.’s original paper.
Figure 2: Self-reported psychological symptoms from pickleball noise exposure.
Figure 3: Pickleball noise sound pressure trace. Image courtesy of Lance Willis, Spenderian and Willis, Tucson, AZ.
Figure 4: One day, 4 courts, hourly distribution of 21,208 total pops. Image courtesy of Noise Net Operations US, Inc.
Figure 5: A typical day of pickleball noise exposure for a neighbor near busy courts.
