Michael Kundakcioglu – mkundakcioglu@hgcengineering.com
HGC Engineering, 2000 Argentia Road, Plaza One, Suite 203, Mississauga, Ontario, L5N 1P7, Canada
Jessica Tinianov
Adam Doiron
Popular version of 1aAA9 – Sound flanking through common low-voltage electrical conduit in multi-family residential buildings
Presented at the 186th ASA Meeting
Read the abstract at https://doi.org/10.1121/10.0026642
–The research described in this Acoustics Lay Language Paper may not have yet been peer reviewed–
Residents living in an apartment or condominium expect a certain amount of privacy, especially when it comes to noise intrusions from neighbours. In fact, there are Building Code requirements in most jurisdictions which outline minimum requirements for the design of suite-demising architectural assemblies, to limit the allowable amount of sound that can go directly through (or in some cases, around) walls, floors, and ceilings. Despite this, sometimes, noise finds a way to travel through the building in unexpected ways, sometimes bypassing these assemblies. One such “sneaky” path is through the electrical conduits – those tubes that carry electrical wires between suites.
These conduits can act like a highway for sound, especially if they’re not sealed properly at certain points, like where they connect to fire alarms. This can allow noise from one suite to easily travel to another, even if the walls are properly designed to block sound. It’s a bit like having string from one suite to another, tied to a foam cup on each side, like those makeshift telephones we used to make as children.
This isn’t just a minor annoyance; it can be a big problem. In fact, this conduit issue has been found in multiple buildings in recent times, and it can reduce the effectiveness of the walls that are meant to keep sound in – by quite a bit. In many cases, this simple flaw in construction can cause the sound transmission between suites to fail Building Code requirements mentioned above, depending on the local requirements.
The good news is that this can be prevented. Sealing the open holes at the end of the conduits with simple flexible caulking on both sides of the tube greatly reduces the amount of noise from traveling through them (see Figure 1 below). It’s a simple solution that can make a big difference in the level of noise intrusion between suites.
Figure 1: Unsealed Conduit Opening in Fire Alarm Junction Box (Left), and Conduit Opening after Applying Sealant (Right). Image Courtesy of HGC Engineering
Standard sound transmission testing (known as Apparent Sound Transmission Class or ASTC testing) has shown that sealing these conduits can reduce the amount of sound travelling through the conduit so much that the amount of sound transmitted from suite-to-suite returns to the expected design values. In Figures 2 and 3 below, we plot the amount of sound transmitted between two adjacent suites as tested in four different real-world buildings with three different wall types separating the suites (double steel stud walls in Figure 2, and poured concrete walls in Figure 3); the dotted lines represent the amount of sound blocked by the wall when the conduit routed between the suites is left unsealed, while the solid lines represent the amount of sound blocked when the conduit has been sealed with caulking.
Figure 2: Steel Stud Walls Transmission Loss Results, as Tested by HGC Engineering
Figure 3: Poured Concrete Walls Transmission Loss Results, as Tested by HGC Engineering
In the above tests, we see the ASTC rating increase by 5 to 10 points once the conduits are sealed, which is a significant and very noticeable difference. In conclusion, if you are a developer, builder, architect, or engineer, it might be worth looking into whether the conduits in the suites in your buildings are properly sealed. It’s a fix that can help everyone get back to enjoying their own space in peace.
Quentin Brissaud – quentin@norsar.no
X (twitter): @QuentinBrissaud
Research Scientist, NORSAR, Kjeller, N/A, 2007, Norway
Sven Peter Näsholm, University of Oslo and NORSAR
Marouchka Froment, NORSAR
Antoine Turquet, NORSAR
Tina Kaschwich, NORSAR
Popular version of 1pPAb3 – Exploring a planet with infrasound: challenges in probing the subsurface and the atmosphere
Presented at the 186 ASA Meeting
Read the abstract at https://doi.org/10.1121/10.0026837
–The research described in this Acoustics Lay Language Paper may not have yet been peer reviewed–
Low frequency sound, called infrasound, can help us better understand our atmosphere and explore distant planetary atmospheres and interiors.
Low-frequency sound waves below 20 Hz, known as infrasound, are inaudible to the human ear. They can be generated by a variety of natural phenomena, including volcanoes, ocean waves, and earthquakes. These waves travel over large distances and can be recorded by instruments such as microbarometers, which are sensitive to small pressure variations. This data can give unique insight into the source of the infrasound and the properties of the media it traveled through, whether solid, oceanic, or atmospheric. In the future, infrasound data might be key to build more robust weather prediction models and understand the evolution of our solar system.
Infrasound has been used on Earth to monitor stratospheric winds, to analyze the characteristics of man-made explosions, and even to detect earthquakes. But its potential extends beyond our home planet. Infrasound waves generated by meteor impacts on Mars have provided insight into the planet’s shallow seismic velocities, as well as near-surface winds and temperatures. On Venus, recent research considers that balloons floating in its atmosphere, and recording infrasound waves, could be one of the few alternatives to detect “venusquakes” and explore its interior, since surface pressures and temperatures are too extreme for conventional instruments.
Sonification of sound generated by the Flores Sea earthquake as recorded by a balloon flying at 19 km altitude.
Until recently, it has been challenging to map infrasound signals to various planetary phenomena, including ocean waves, atmospheric winds, and planetary interiors. However, our research team and collaborators have made significant strides in this field, developing tools to unlock the potential of infrasound-based planetary research. We retrieve the connections between source and media properties, and sound signatures through 3 different techniques: (1) training neural networks to learn the complex relationships between observed waveforms and source and media characteristics, (2) perform large-scale numerical simulations of seismic and sound waves from earthquakes and explosions, and (3) incorporate knowledge about source and seismic media from adjacent fields such as geodynamics and atmospheric chemistry to inform our modeling work. Our recent work highlights the potential of infrasound-based inversions to predict high-altitude winds from the sound of ocean waves with machine learning, to map an earthquake’s mechanism to its local sound signature, and to assess the detectability of venusquakes from high-altitude balloons.
To ensure the long-term success of infrasound research, dedicated Earth missions will be crucial to collect new data, support the development of efficient global modeling tools, and create rigorous inversion frameworks suited to various planetary environments. Nevertheless, Infrasound research shows that tuning into a planet’s whisper unlocks crucial insights into its state and evolution.
American University, Department of Performing Arts, American University, Washington, DC, 20016, United States
Braxton Boren, Department of Performing Arts, American University
X (twitter): @bbboren
Popular version of 2pAAa12 – Acoustics of two Hindu temples in southern India
Presented at the 186th ASA Meeting
Read the abstract at https://doi.org/10.1121/10.0027050
–The research described in this Acoustics Lay Language Paper may not have yet been peer reviewed–
What is the history behind the sonic experiences of millions of devotees of one of the oldest religions in the world?
Hindu temple worship dates back over 1,500 years. There are Vedic scriptures from the 5th century C.E describing the rules for temple construction. Sound is a key component of Hindu worship, and consequently, its temples. Acoustically important aspects include, the striking of bells, gongs, blowing of conch shells, and chanting of the Vedas. The bells, gongs, and conch shells all have specific fundamental frequencies and unique sonic characteristics that play out of them, while the chanting is specifically stylized to include phonetic characteristics such as pitch, duration, emphasis, and uniformity. This great prominence of the frequency domain soundscape makes Hindu worship unique. In this study, we analyzed the acoustic characteristics of two UNESCO heritage temples in Southern India.
Figure 1: Virupaksha temple, Pattadakal
The Virupaksha temple in Pattadakal, built around 745 C.E, is part of one of the largest and ancient temple complexes in India.1 We performed a thorough analysis of the space, taking sine sweep measurements from 36 different source-receiver positions. The mid-frequency reverberation time (the time it takes for the sound to decay by a level of 60dB) was found to be 2.1s and the clarity index for music, C80 was -0.9dB. Clarity index is a metric that tells us how balanced the space is and how well complex passages of music can be heard. A reverberation time of 2.1s is similar to a modern concert hall’s reinforcement, and a C80 of -0.9dB means that the space is very good for complex music too. In terms of the music performed, it would be a combination of vocal and instrumental South Indian music with the melodic framework being akin to melodic modes of western classical music set to different time signatures and played at various tempi ranging from very slow (40-50 beats per minute) to very fast (200+ beats per minute).
Figure 2: The sine sweep measurement process in progress at the Virupaksha temple, Pattadakal
The second site was the 15th century Vijaya Vittala temple in Hampi which is another major tourist attraction. Here the poet, composer, and the father of South Indian classical music, Purandara Dasa, spent many years creating compositions in praise of the deity. He was known to have created thousands of compositions in many complex melodic modes.
Measurements at this site spanned 29 source-receiver positions with the mid-frequency reverberation time being 2.5s and the clarity index for music, C80 being -1.7dB. These values also fall in the ideal range for complex music to be interpreted clearly. Based on these findings, we conclude that the Vijaya Vittala temple provided the optimum acoustical conditions for the performance and appreciation of Purandara Dasa’s compositions and South Indian classical music more broadly.
Other standard room acoustic metrics have been calculated and analyzed from the temples’ sound decay curves. We will use this data to build wave-based computer simulations and further analyze the resonant modes in the temples, study the sonic characteristics of the bells, gongs, and conch shells to understand the relationship between the worship ceremony and the architecture of the temples. We also plan to auralize compositions of Purandara Dasa to recreate his experience in the Vijaya Vittala temple 500 years ago.
1 Alongside the ritualistic sounds discussed earlier, music performance holds a vital place in Hindu worship. The Virupaksha temple, in particular, has a rich history of fulfilling this role, as evidenced by inscriptions detailing grants given to temple musicians by the local queen.
Arup, Suite 900, Toronto, Ontario, M4W 3M5, Canada
Vincent Jurdic
Chris Pollock
Willem Boning
Popular version of 1aAA13 – The cost of transparency: balancing acoustic, financial and sustainability considerations for glazed office partitions
Presented at the 186th ASA Meeting
Read the abstract at https://doi.org/10.1121/10.0026646
–The research described in this Acoustics Lay Language Paper may not have yet been peer reviewed–
I’m an acoustician and here’s why we need to use less glass inside office buildings.
Glass partitions are good for natural light and visual connection but how does glass perform when it comes to blocking sound? What about the environmental cost? These questions came up when my team was addressing problems with acoustic privacy in a downtown Toronto office building. One of the issues was the glass partitions (sometimes called a “storefront” system) between private offices or meeting rooms and open office areas. Staff reported overhearing conversations outside these offices, an issue that ranges from just being distracting to undermining confidentiality for staff and clients.
Glass is ubiquitous in office buildings, inside and out. As a façade system, it’s been a major part of the modern city since at least the 1950s. Inside offices, it often gives us a sense of connection and inclusivity. But as an acoustician, I know that glass partitions are not effective at blocking sound compared to traditional stud walls or masonry walls. How good or bad depends on the glazing design – how thick the glass is, lamination, double panes and air gaps, and how the glass is sealed. When working on fixing the speech privacy problems in the Toronto office, we measured the sound isolation of the glazed partitions by playing random noise very loudly in each office and measuring the sound level difference between that room and the area outside. Our measurements supported the experience of the office staff: conversations are not just audible but comprehensible on the other side of the glass. The seals around the sliding doors often had gaps and sometimes there were joints without any seals – big enough to put your fingers through. Sound is made by tiny fluctuations in air pressure; even small gaps can be a problem.
Figure 1: Example of glass storefront with a sliding door and no seal (Arup image)
This acoustics problem led me to other questions about the cost of transparency in offices, especially the carbon cost. Glass is energy-intensive to produce. Per unit area, ¼” glass can require seven times the embodied carbon of one layer of 5/8” type X gypsum. When Arup compared several glazed partition systems that all had about the same acoustic performance, we found the glass was the greatest contributor to carbon emissions compared to all the other components (see Figure 2). Using these embodied carbon values, we estimated that the carbon cost of all the glazed partitions in this particular office was about 56,800 kgCO2eq, equivalent to driving one-way from New York to Seattle 51 times in an average gasoline-powered car.
Figure 2: Embodied carbon for typical aluminum storefront with three glazing buildups with the same sound isolation rating (Arup research)
So how should these costs be balanced? First, acousticians should be involved early on in space planning and can encourage architects to use less glazing to achieve the design outcomes, including acceptable acoustic performance. Second, we could encourage designers to create a glass aesthetic that uses “less perfect” glass in some locations. Offices may not require the degree of transparency that has become the norm. Where visual privacy is important, glass made from recycled cullet could be specified, leaving the perfectly transparent glass manufactured from virgin silica sand for key locations where a strong visual connection matters. The right balance depends on the project, but asking questions about the multiple costs of transparency is a good place to start.
Prisons can be noisy places, but thoughtful design can lower stress and improve conditions for both staff and prisoners.
SYDNEY, Dec. 6, 2023 – Prisons are typically noisy environments, filled with clanking metal bars and echoing concrete surfaces. This level of constant noise is harmful to both prisoners and staff, but there are few guidelines for designing better, quieter facilities.
James Boland, an acoustician for SLR Consulting, employed insights from the field of sensory criminology to better understand the unique acoustic needs inside prison environments. His presentation will take place Dec. 6 at 2:40 p.m. Australian Eastern Daylight Time, as part of Acoustics 2023 Sydney, running Dec. 4-8 at the International Convention Centre Sydney.
Sound and noise inside prisons can affect both staff and inmates, so a thorough understanding of that noise is crucial when designing prison spaces. Credit: Helen Farley
“Sensory criminology examines how sensory experiences, such as sight, sound, and touch, influence and shape perceptions of crime and justice,” said Boland. “It emphasizes the impact of auditory elements on the experiences of both prisoners and staff and considers how the constant noise contributes to the overall atmosphere, perceptions, and communication within the prison environment.”
Auditory guidelines for prisons are often adapted from existing protocols for schools and hospitals. However, prisons are unique environments with different relationships to sound and noise. For instance, both prisoners and staff rely on noise to gauge the level of social tension. A prison that is ‘too quiet’ can sometimes be worse than one that is too loud.
In the context of prisons, acoustic design can contribute to transforming communication dynamics and alleviating negative social interactions. By focusing on speech intelligibility, strategic reduction of noise levels, and the incorporation of privacy considerations, acoustic design can significantly improve the overall prison environment. Creating distinct zones within the prison and balancing moments of quiet with activity are essential to fostering a more comfortable and secure space.
“The crux lies in recognizing the significance of ‘noise’ from the perspective of those inhabiting these spaces,” said Boland. “For prisoners, it’s about how sound influences their outlook in terms of power or dynamic safety in their daily lives, while for staff, it becomes a tool for decision-making and maintaining safety for themselves and those under their care.”
By seeking input from the people who occupy and live in these spaces, Boland hopes to gain an understanding of the complex role of sound inside prisons. Such an understanding could lead to better guidelines for current and future prison facilities, benefiting everyone inside.
“Ultimately, thoughtful acoustic design in prisons can directly influence the lived experiences of individuals, promoting positive social interactions and supporting rehabilitation efforts,” said Boland.
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/
Ben Cazzolato – benjamin.cazzolato@adelaide.edu.au
The University of Adelaide, Adelaide, SA, 5005, Australia
Cameron West
Acoustic Blinds and Curtains
Sydney, New South Wales, Australia
Tyler Schembri
The University of Adelaide
Forestville, South Australia, Australia
Peter Watkins
Acoustic Blinds and Curtains
Sydney, New South Wales, Australia
Will Robertson
The University of Adelaide
Forestville, South Australia, Australia
Popular version of 2pAA3 – Enhancing acoustic comfort with window coverings: Reducing sound transmission and reverberation times with a single product
Presented at the 185th ASA Meeting
Read the abstract at https://doi.org/10.1121/10.0023007
Please keep in mind that the research described in this Lay Language Paper may not have yet been peer reviewed.
Noise pollution isn’t just a nuisance, it’s bad for your health. Prolonged noise exposure has been linked to several short and long-term health problems – both physiological and psychological. The World Health Organization has estimated an annual loss of “at least one million healthy years of life” due to traffic noise alone.
Traditionally curtains and drapes have been used for design and light control only. However, they also present a great opportunity for a comprehensive acoustic treatment. This is for a number of reasons:
They are installed over windows and glazing, which is where the sound commonly enters spaces;
Windows generally have a significant surface area and are typically very reflective, which presents an opportunity to remove noise via absorption when covered;
Unlike other acoustic treatments, they are a natural fit in most modern spaces allowing architects, designers and clients freedom in their design unconstrained by acoustics.
Extensive testing by qualified acoustic engineers in the Acoustic and Vibration Laboratories at the University of Adelaide, Australia have shown that it is possible to reduce noise pollution by more than half* with an acoustic interlining. The acoustic interlining is a mass layer that is sandwiched between two sound absorbing curtain fabrics. Together these layers block and absorb sound.
Figure 1: Measuring the sound transmission loss and sound absorption of an acoustic curtain in a reverberation chamber at the University of Adelaide.
The acoustic interlining was tested over four glazing conditions; open window, 4mm glass, 6.38mm glass and 10.38mm glass, across 15 different curtain configurations, totalling 76 tests. The plot below shows the reduction in sound pressure level in a receiving room when using a typical acoustic curtain as a room divider. In the plot we compare only using the interlining, using only the face fabrics, and the benefit of combining both face fabrics and interlining, with the latter providing a frequency-weighted improvement of 17dB. Similar results were obtained when the tests were repeated for the three thicknesses of glazing.
Figure 2: Reduction in sound pressure level (known as the level difference improvement) when using the acoustic curtains as a room divider.
We have generated two audio files demonstrating how these acoustic curtains reduce noise pollution: Room divider application using 1500gsm interlining, and 800gsm interlining over 4mm glazing applied to traffic noise.
Visit the Acoustic Blinds and Curtains website for more details on the curtain construction and informative videos demonstrating how these curtains reduce noise pollution and improve room acoustics.
Our testing has shown how curtains and drapes can reliably reduce noise pollution by more than half for both open and closed windows. This is a game-changer for architects and end-users looking for simple, cost effective noise reduction and sound absorption compared to other acoustic products and offer a functional alternative to traditional blinds and curtains.
Figure 1: Unsealed Conduit Opening in Fire Alarm Junction Box (Left), and Conduit Opening after Applying Sealant (Right). Image Courtesy of HGC Engineering
Figure 1: Unsealed Conduit Opening in Fire Alarm Junction Box (Left), and Conduit Opening after Applying Sealant (Right). Image Courtesy of HGC Engineering
Figure 2: Steel Stud Walls Transmission Loss Results, as Tested by HGC Engineering
Figure 2: Steel Stud Walls Transmission Loss Results, as Tested by HGC Engineering
Figure 3: Poured Concrete Walls Transmission Loss Results, as Tested by HGC Engineering
Figure 3: Poured Concrete Walls Transmission Loss Results, as Tested by HGC Engineering
Low frequency sound, called infrasound, can help us better understand our atmosphere and explore distant planetary atmospheres and interiors.
Figure 1: Measuring the sound transmission loss and sound absorption of an acoustic curtain in a reverberation chamber at the University of Adelaide.
Figure 2: Reduction in sound pressure level (known as the level difference improvement) when using the acoustic curtains as a room divider.