Resolut Group 181 E 5600 S, Suite 200 Murray, UT, 84123
Popular version of 2pAAa6 – Measurement-informed orientation of an amphitheater surrounded by natural rock formations using in-situ impulse response analysis. Presented at the 190th ASA Meeting Read the abstract at https://eppro01.ativ.me/web/planner.php?id=ASASPRING2026
–The research described in this Acoustics Lay Language Paper may not have yet been peer reviewed–
A venue’s beauty may draw guests in, but the acoustic experience is what brings them back.
When attending a symphony, the first desired experience is to hear and appreciate music. Musical quality is important for design aspects of an outdoor amphitheater, especially when the design is impacted by large, natural rock formations. Maxwell Park in Hilldale, UT contains several striking, extraordinary features that naturally catch any eye. Although there’s beauty in this scenery, acoustic tests were needed to help enhance the listening experience, i.e., find the best stage direction. Because of these colossal rocks, the way the stage faces can strongly change what the audience hears.
During predesign, two realistic stage orientations were compared: a stage on the north side facing south (Figures 1-3), and a stage on the east side facing west (Figures 4-6). The orientation matters because rocks are reflective and if reflections arrive at the audience at different times and from different directions, they can smear the sound and make music feel less clear. To find the best option, four types of tests were performed at each orientation: an impulse response test (to see when echoes arrive), a “chirp” test (to check how different pitches carry and whether they interfere), a real-time analysis (to see how evenly sound spreads across the audience area), and a music listening test (to hear the real-world result). The client team, including several city officials and the architect, was on-site during testing and though graphs, tables, and data analyses are useful, hearing the difference in-person made the greatest impression.
Figure 1: Northern Stage Design
Figure 2: Northern Stage Simulation
Figure 3: Southern Audience Area
Figure 4: Eastern Stage Design
Figure 5: Eastern Stage Simulation
Figure 6: Western Audience Area
From the north side, sound struck the nearby eastern rock face almost immediately and provided positive reinforcement for the direct sound. However, the sound reflecting off the western rock face arrived at a significant delay causing negative reinforcement which distorted the overall quality. Those repeated reflections, arriving at slightly different times, blurred the sound, made it harder to tell where the music was originating, and confused listeners. During the music listening test, the clients were so distracted that some initially assumed the sound equipment was the problem, calling it, “low quality”.
On the east side, the audience heard stronger direct sound, with only mild reflections from farther rock formations. Those reflections helped the sound feel full and supportive. During the music listening test, listeners described their experience as clear, impactful, more evenly heard across the area, and emotional to the music that was played. The same equipment and music were used for both orientations, but the natural rock formations from the eastern side had the greatest acoustic impact.
Measurements, figures, and charts help explain why one option performs better, but the shared, real-time listening experience made the difference. Based on that direct experience (supported by test results), the east-side stage orientation was the clear recommendation to, and accepted by, the client.
Textured walls improve speech clarity, making an easier listening experience for all.
PHILADELPHIA, May 14, 2026 — According to many deaf and hard-of-hearing individuals, clarity — not volume — is one of the most challenging parts of understanding speech in enclosed spaces. In many types of rooms, sound reflecting off multiple walls muddies conversation, making it harder to understand.
“For most people, this might just feel like background noise,” said researcher Po-Chun Chou, a researcher from the University of Michigan. “But for deaf and hard-of-hearing individuals, it can significantly affect their ability to follow conversations — especially when it comes to distinguishing important speech details like consonants.”
But making spaces quieter isn’t a perfect solution — what matters is controlling how sound travels in a room. To do so, Chou developed a patterns wall to improve the listening experience of deaf and hard-of-hearing individuals.
Chou will present these designs Thursday, May 14, at 3:40 p.m. ET as part of the 190th Meeting of the Acoustical Society of America, running May 11-15.
The modular wall is put together using building blocks fabricated by 3D printing. Credit: Po-Chun Chou
The researchers began by conducting acoustic simulations to study how different surface textures influenced speech clarity to determine the patterns for their wall. Then, they conducted experiments to validate their findings and observe how the designs affect sound behavior in real life.
Instead of building an entire wall, they designed “tiles” that could fit together like a puzzle, linking them together to fit different room shapes and sizes. These pieces were fabricated using a 3D printer.
“One key finding is that the acoustic performance of a wall can be precisely controlled through geometry and fabrication parameters — not just traditional materials.” Chou said.
Surprisingly, they found that different patterns and 3D printing settings impact different frequency ranges, meaning that the wall designs can be personalized to different user experiences.
Since this research was inspired by personal experiences, Chou hopes others will understand that challenges for deaf and hard-of-hearing individuals can be amplified by their environments.
“Architectural acoustics should not be seen only as a matter of comfort — it can also be a matter of accessibility,” Chou said. “By integrating design, digital fabrication, and acoustic performance, we can create spaces that support clearer communication. This benefits not only deaf and hard-of-hearing users, but everyone who uses the space.”
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For more information: AIP Media 1 301.209.3090 media@aip.org
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 the in-person conference at the Philadelphia Marriott Downtown for credentialed and professional freelance journalists. If you are a reporter and would like to attend the meeting and/or 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 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/.
Donaghey College of Science, Technology, Engineering, and Mathematics, University of Arkansas at Little Rock, Little Rock, Arkansas, 72204, United States
Andrew B Wright
Popular version of 5aAA6 – A Small Reverberation Chamber to Measure Sound Transmission Loss in 3D-Printed Structures
Presented at the 190th ASA Meeting
Read the abstract at https://eppro01.ativ.me/web/planner.php?id=ASASPRING2026
–The research described in this Acoustics Lay Language Paper may not have yet been peer reviewed–
Imagine a team of small robots moving through a warehouse, using sound to sense and communicate. The components that control noise in these systems are often around the size of your hand. Yet testing how well these small parts block sound can require a room-sized setup.
While this may sound excessive, it reflects how sound-blocking performance is commonly measured today. The ability of a material to block sound is quantified using Sound Transmission Loss (STL), which is typically evaluated using standardized methods such as the reverberation room and impedance tube.
The reverberation room method requires a large room (>50 m³) to measure the STL of a large sample (approx. 2.4 m). To illustrate this, consider heating a sandwich using an entire room instead of a microwave. Modern 3D printing technology enables the inexpensive production of many designs, but these structures are typically small (approx. 0.02 m³). For such small samples, the reverberation room method cannot be applied directly. One possible workaround is to combine multiple small samples into a larger one, similar to assembling many small sandwiches into one large sandwich. However, this approach is cumbersome, time-consuming, and expensive.
The other impedance tube method can measure the STL of small samples, but only for sound waves that strike the sample perpendicularly. Using the earlier analogy, this is similar to heating a sandwich with a torch from only one direction rather than heating it evenly from all sides.
While both standardized methods are useful, they have limitations when applied to small structures. This research presents the design and validation of a novel small reverberation chamber (0.49 m³, see Figure 1). In the earlier analogy, this chamber functions like a microwave, efficient and suited to the size of the sample.
In this setup (see Figure 2), the STL offered by the small sample is measured using a sound input and corresponding waveforms recorded through microphones. A customized programming script developed in this research performs mathematical analysis on the waveform, and the STL is calculated.
Figure 2: Experimental Setup Example
The effectiveness of the chamber is validated by comparing the STL of two known materials against values measured using this system. The observed measurement error was low (±2.75 dB). Although this does not meet ASTM standard’s specifications (±2 dB), it is sufficient as an inexpensive solution for rapid STL characterization. Finally, the STL of four 3D-printed specimens was evaluated under different infills (50% and 100%) and material combinations (PLA, ABS, PLA+TPU, ABS+TPU) across various frequencies.
As modern designs continue to shrink, from small robotic systems to everyday devices, the ability to evaluate sound performance at the same scale becomes essential. The proposed small reverberation chamber enables this shift by allowing compact, noise-controlling components to be tested as they are actually used, supporting more effective noise-reducing designs.
Acentech, 33 Moulton St., Cambridge, MA, 02138, United States
Popular version of 2aAAb1 – Signal-to-noise ratio in restaurants: fine lines between terrific and terrible dining experiences
Presented at the 190th ASA Meeting
Read the abstract at https://eppro01.ativ.me/web/planner.php?id=ASASPRING2026
–The research described in this Acoustics Lay Language Paper may not have yet been peer reviewed–
Restaurant noise is one of the most common acoustical complaints. Since a truly quiet restaurant is an empty one, the question becomes, “how much are diners willing to cope with noise as a trade-off for good food and a fun night out?”.
Crowdsourced data from the app SoundPrint, which has logged more than 100,000 noise measurements in restaurants, suggests that the difference between a restaurant where conversation feels easy and one where it feels exhausting is relatively small: only about 7 decibels (dB), which is about the difference between a raised and normal speaking voice. And the average noise level of a “quiet” restaurant? Approximately 70 dBA. The dBA unit indicates that the noise was adjusted to approximate the human ear’s response to sound.
Figure 1 – Soundprint User Interface. Customers measure fifteen seconds of noise and then rate their ability to have a conversation (courtesy of SoundPrint).
This might seem very loud if you’ve ever used a sound level meter app on your phone. Because it is – our indoor environments are purposefully designed to be 45 dBA or much quieter to provide comfort, rest, and the right environment for mentally demanding tasks like business conference calls or listening to class lectures.
Restaurants test the resilience of our hearing system and require a combination of visual and auditory cues to fill in the gaps. Whether or not we can clearly see the person’s face, pick up context clues from the conversation, or know the person’s voice all play a role in helping us understand each other in restaurants. If you are about to have a business dinner with someone you’ve never met before, think twice about where you are going and pull up a few photos. Does the ceiling look shiny and seamless? Are the tables close together? Is it mostly mood lighting with table lamps? If so, you might not land that deal.
Figure 2 – A charming restaurant that serves delicious food; however, guests may have a hard time hearing each other during peak hours.
Restaurant noise is not guesswork. Acoustical consultants can study architectural drawings, occupancy counts, and room finish materials to determine noise levels in restaurants based on the number of customers. If restaurant owners want to fix the issue, the optimal solution often must accommodate tight operating margins: find the cost-effective, minimally invasive solution.
The cacophony of restaurants is often simple oversight: the designer did not hire an acoustical consultant and opted for a sound-reflective ceiling material instead of a sound-absorbing ceiling. The reason this remains a consistent issue even after the restaurant has opened is far more complex: a noisy packed dining room suggests a thriving restaurant, creates turnover, and a tight table arrangement means more paying customers. Restaurants are a business and noisemakers are the clients. Add a thumping soundtrack to the mix and you have a perfect recipe for a strained voice and splitting headache.
A quiet restaurant is an empty one. However, owners, designers, and consultants can establish realistic goals if we reference crowdsourced data and reframe what quiet means in the context of restaurants. Practical advice from acoustical consultants can make all the difference between a terrible and acceptable dining experience, increasing the chance that customers come back.
If it is any solace, restaurants have been obnoxiously loud for nearly a century (see Figure 3).
Figure 3: Noise levels found at home and in restaurants. Adapted from “Present Methods of Sound Measurement” by A.H. Davis, (Architects’ Journal, May 1938)
Even though timber requires extra material to insulate noise, it can still be more climate-friendly than steel or concrete. #ASA_ASJ2025 #ASA189
HONOLULU, Dec. 3, 2025 — Many modern buildings are “green buildings,” adhering to a complex set of standards to ensure they are environmentally friendly and sustainably designed, with minimal impact on nature and the humans that inhabit them. These standards can govern everything from energy efficiency to construction materials used for acoustic privacy between rooms.
The sheer number of factors to consider when designing such a building can make even veteran architects stumble. Even deciding which construction material to use requires accounting for cost, lifetime carbon emissions, and acoustic performance.
Acoustic consultant George Edgar will present his assessment of various wall and floor types for their climate impact and acoustic performance Wednesday, Dec. 3, at 8:20 a.m. HST as part of the Sixth Joint Meeting of the Acoustical Society of America and Acoustical Society of Japan, running Dec. 1-5 in Honolulu, Hawaii.
The global warming potential (A1-A3) of two wall systems calculated using INSUL®’s in-development carbon calculation tool. Credit: Marshall Day Acoustics
Sound and noise have a major impact on our ability to focus and communicate, which is why acoustic requirements often feature in green building standards, such as LEED in the U.S. and BREEAM in the U.K.
“The leading voluntary green building schemes in major English-speaking countries and Japan all include credits for acoustics,” said Edgar. “These schemes acknowledge the impact acoustic comfort has on the well-being of a building’s occupants.”
Edgar evaluated multiple materials, including timber, steel, and concrete, for their sound insulating properties along with their global warming potential (GWP), a measure of the carbon emissions involved in manufacturing them.
“The primary factor that influences GWP in the manufacturing phase is the amount of energy, and therefore carbon emissions, required to produce the material,” said Edgar. “Concrete and steel are more energy-intensive to produce than timber products, so they have higher GWP values in the manufacturing phase.”
Edgar found that, for floors with a given sound insulation performance, concrete could have a far higher GWP than timber, and walls that incorporated timber outperformed standard steel studs, even when they needed more wall linings to achieve the same acoustic performance.
Despite the importance of these results, little research has been done examining both the acoustic performance and climate impacts of building materials. Edgar is optimistic that his work will lead to buildings that are both quiet and climate-friendly.
“As acoustic consultants, an awareness of the GWP associated with the design solutions we specify can help us to make a positive impact on our environment for generations to come,” said Edgar. “I’d like to see more research in this area so we can all make more informed decisions when considering acoustics and sustainability.”
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 and/or 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 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 ACOUSTICAL SOCIETY OF JAPAN ASJ publishes a monthly journal in Japanese, the Journal of the Acoustical Society of Japan as well as a bimonthly journal in English, Acoustical Science and Technology, which is available online at no cost https://www.jstage.jst.go.jp/browse/ast. These journals include technical papers and review papers. Special issues are occasionally organized and published. The Society also publishes textbooks and reference books to promote acoustics associated with various topics. See https://acoustics.jp/en/.
Dr.-Ing Tim Karl
Professur für Mechatronik
Helmut-Schmidt-Universität
Hamburg
Popular version of 3pAA10 – Fifteen Years of Research on Active Noise Control Systems for Partially Open Windows: A Summary of Key Findings
Presented at the 189th ASA Meeting
Read the abstract at https://doi.org/10.1121/10.0040847
–The research described in this Acoustics Lay Language Paper may not have yet been peer reviewed–
Motivation
In many cities, people want to keep their windows open to allow fresh air into their homes. However, especially in busy urban areas, open windows also let in unwanted noise from traffic, trains, aircraft, and general city activity. Constant exposure to this noise is not just annoying, it can affect sleep, concentration, and even long-term health. To address this problem, researchers at the Helmut Schmidt University in Hamburg have spent the past fifteen years developing systems that can reduce noise coming through partially open windows while still allowing natural ventilation.
Passive Absorbers
The approach combines two methods: passive noise reduction and active noise control (ANC). Passive noise reduction involves using materials that naturally absorb or block sound, such as foam-like acoustic panels or special seals. These materials are very good at reducing high-frequency noise but are less effective for deeper, low-pitched sounds like engines or traffic rumble.
ActiveNoise Control
This is where active noise control comes in. ANC works in a way similar to noise-cancelling headphones. Small loudspeakers placed near the window play “anti-noise sound waves” that are shaped to cancel out incoming noise. When the incoming noise and the anti-noise meet, they interfere with each other and reduce the amount of sound that reaches inside the room. To make this happen, microphones are used to measure the sound, while computer algorithms constantly adjust the sound from the speakers to keep the cancellation effective.
Figure 1: Internoise 2020, J. Hanselka, D. Sachau, Converting an Active Noise Blocker for a Tilted Window from Feedforward Control into a Feedback System
Algorithm
worked on improving the computer algorithms that run the ANC system. These algorithms need to react quickly to changing noise, remain stable, and avoid using too much power. Therefor analyses conduction different real-time-controller platforms were evaluated, including DSP and FPGA technology
Figure 2: ISMA 2014, D. Sachau, S. Jukkert, Real-time implementation of the frequency-domain FxLMS algorithm without block delay for adaptive noise blocker
Simulation
However, using ANC at an open window is much more complicated than inside headphones. The sound field near an open window is irregular and constantly changing because of airflow, reflections, and outdoor conditions. The research team therefore studied how sound moves through small openings of different shapes and sizes. One important discovery is that the depth of the opening relative to the wavelength of the sound plays a enormous role in how much noise gets through. This knowledge helps guide how the ANC system can be designed and placed.
Figure 3: Internoise2020, M. Sandner, D. Sachau, Influence of parameters of small gaps regarding sound transmission and ANC-performance-a numerical simulation
Position Optimization
Another major research effort focused on the best positions for microphones and speakers. Their placement determines how well the noise can be cancelled. The researchers found that placing the speaker near the center of the opening often provides the most even noise reduction throughout the room. Meanwhile, microphone placement is very important for stability, because the microphone input is what guides the control system in real time.
Figure 4: DAGA 2025, T. Karl, D. Sachau, Numerical position optimization approach for sensor and actuator placement in an active noise cancelling system
Conclusion
Overall, the research shows that a combination of passive materials and active noise control is the best approach. Passive elements reduce parts of the noise that are hard to cancel electronically, while ANC handles the deep, low-frequency noise that humans find especially disturbing. Together, these methods make it possible to keep windows open for fresh air -without letting in the city.
Figure 1: 
Figure 2: Experimental Setup Example
Figure 1 – Soundprint User Interface. Customers measure fifteen seconds of noise and then rate their ability to have a conversation (courtesy of SoundPrint).
Figure 2 – A charming restaurant that serves delicious food; however, guests may have a hard time hearing each other during peak hours.
Figure 3: Noise levels found at home and in restaurants. Adapted from “Present Methods of Sound Measurement” by A.H. Davis, (Architects’ Journal, May 1938)
Figure 1: Internoise 2020, J. Hanselka, D. Sachau, Converting an Active Noise Blocker for a Tilted Window from Feedforward Control into a Feedback System
Figure 2: ISMA 2014, D. Sachau, S. Jukkert, Real-time implementation of the frequency-domain FxLMS algorithm without block delay for adaptive noise blocker
Figure 3: Internoise2020, M. Sandner, D. Sachau, Influence of parameters of small gaps regarding sound transmission and ANC-performance-a numerical simulation
Figure 4: DAGA 2025, T. Karl, D. Sachau, Numerical position optimization approach for sensor and actuator placement in an active noise cancelling system