bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of sounds on the visitors' experience in museums
Authors: Bem Milena J. , Chabot Samuel R. V. , Braasch Jonas
Published: November 2023

Museums increasingly recognize the significance of acoustics for a high-quality visitor experience. Objective/physical parameters have been extensively studied, but there is a need for research focusing on user perception. This study addressed this gap by investigating visitors' soundscape preferences and the effects of different soundscapes on the museum experience. We hypothesized that exhibition-congruent sounds are more effective than conventional masking sounds in reducing distractions, enhancing engagement with artwork, and creating immersive experiences. The research utilized the Cognitive Immersive Room (CIR) at Rensselaer Polytechnic Institute, featuring a 360° visual display with a multi-channel loudspeaker system for spatial audio rendering to project panoramic photographs and ambisonic audio recordings recorded in 16 exhibitions in five relevant museums—for example, MASSMoca and the New York State Museum. Four scenarios were presented to the participants: originally recorded soundscape, recorded soundscape combined with a conventional sound masker, recorded soundscape combined with a congruent sound masker, and silence. After experiencing the immersive environment, 23 subjects responded to a questionnaire. The results showed congruent sounds increased focus and engagement and contributed to a more comprehensive and immersive experience. In 58% of cases, the participants preferred the congruent-sound scenario over the others.
Cavitation-enhanced high-intensity focused ultrasound treatment for cancer therapy
Authors: Umemura Shin-ichiro , Yoshizawa Shin , Okamoto Jun , Nemoto Kazuhito
Published: November 2023

Cavitation has been known to have a potential to enhance HIFU treatment in a few ways. It can multiply the particle displacement by orders of magnitude and thereby enhance the mechanical effect (1) of ultrasound hugely and the in vivo thermal effect (2) significantly. It can even induce chemical effect (3) when its bubble collapses. We are developing a cavitation-enhanced HIFU therapy system by which the effects (2) and (3) are aimed to obtain. The higher priority was set on the effect (2), because combination with a certain drug may be needed for the effect (3), which can make the process for the approval more difficult. In vivo cavitation threshold can hugely vary on the conditions. It can be reduced by stabilized microbubbles and nanobubbles, nanodroplets, and certain chemicals. However, these are not assumed in combination with our system for the same reason above. Instead, an ultrasonic pulse at an extremely high-intensity in the order of 10 MPa with a duration in the order of 10 ms is used to generate cavitation, which is immediately followed by a typical HIFU burst to obtain the effect (2). The results from swine tests of our HIFU system will be shown in the presentation.
On the acoustic wedge absorber design in underwater and its interior pressure computation in a chamber
Authors: Chen Pei-Tai
Published: November 2023

This study presents a design of wedged shape absorber used in underwater in range of high frequency. The analysis of a set of periodical wedges, where each wedge is oriented 90 deg with other wedges. The set of periodical wedges is analyzed using finite element methods as a 3-D virtual impedance tube. The incident wave is on the normal direction of the tube. This 3-D model is able to simplify to a simple 2-D model and a two-point transfer function method is employed to compute reflection coefficient. The ation of frequencies higher than the cut-off plane wave frequency is addressed of that higher duct acoustic modes are excited by the wedge. These higher modes are recognized as stationary non-propagating waves, not contributing reflected waves away from the wedge. An impedance value associated with the reflection coefficient is identified based on plane wave condition. The impedance value is applied to surfaces of a closed space to computed interior pressures.
Acoustical effects of extreme weather events
Authors: Yang Jie , Thorsos Eric I. , Ghanem Mohamed A.
Published: November 2023

The transfer of water from evaporating regions to precipitating regions drives the global water cycle, and understanding its dynamics is essential in determining how weather patterns will respond to changes in global climate. An intensification of the global water cycle has been reported using 50-year sea surface salinity data (Durack and Wijffels, 2010, J. Climate) with the consequence of more frequent extreme weather events. However, data under extreme weather conditions over the ocean are rare and a lot of physics remains to be investigated. As part of the Ocean Climate Stations that NOAA is maintaining, the 1-year data presented here are from Ocean Station Papa (50°N, 145°W), including measurements of wind speed, rain rate, currents, wave height and direction, bubble plume spatial structure and dynamics, and ambient noise for wind speeds up to 25 m/s. This full suite of data enables the study of the statistical properties of bubble plumes, their relation to meteorological parameters, and how to take them into account in ambient noise prediction, especially under severe weather conditions. Knowledge gained through this unique dataset can be critical for understanding air–sea interaction, validating satellite rain products, and predicting the ambient noise field under extreme weather conditions.
Tropical cyclones’ acoustic reconnaissance
Authors: Sidorovskaia Natalia , Waxler Roger , Mathew Naomi , Hetzer Claus H.
Published: November 2023

Acoustic reconnaissance of tropical cyclones with underwater gliders is an emerging approach for a comprehensive understanding of the oceanic conditions leading to the formation and intensification of cyclones and for aiding in wind speed forecasting. Shaw et al. (1978) showed that the underwater sound pressure level is in the linear relationship to the logarithm of the moderate local wind speed. Wilson and Makris (2006) proposed an acoustic surface source model for hurricane wind speeds. The model requires a parameterization of the winds’ contribution. The inversion of the acoustic data leads to estimation of the local wind speeds. The Gulf of Mexico acoustic dataset, collected by the bottom-anchored monitoring system during the passage of storm Barry (2019), is analyzed and correlated with the high-resolution wind speed data generated by the Weather Research and Forecast model. The efficacy of gliders outfitted with acoustic system to provide the real-time reporting of the local wind speeds is also discussed based on the flights’ recorded soundscapes. Acoustic glider reconnaissance offers a safe and cost-efficient way of contributing new type data to NOAA and US NAVY weather forecasting models. [Work supported by the Office of the Under Secretary of Defense for Research and Engineering, award# FA9550-21-1-0215.]
Single-value frequency-average measures of early decay time and clarity index to predict reverberance and clarity
Authors: del Solar Dorrego Fernando M. , Vigeant Michelle C.
Published: November 2023

The most accepted acoustical parameters for the assessment of concert hall acoustics are summarized in the Annex A of the ISO 3382-1 standard, along with recommendations that are important for the practical application of these parameters. These recommendations have their origin in the practical experience of acoustical consultants and a few scientific studies, and further research is needed to properly validate them. In particular, more information is needed on how to average the octave-band values of acoustical parameters to obtain single-value frequency-average measures (SVFA) that are better correlated with the associated perceptual aspects. In this study, SVFA measures of early decay time (EDT) and clarity index (C80) were obtained by means of a listening test in which 24 subjects rated a set of stimuli in terms of reverberance and clarity. The participants listened to auralizations of orchestral music convolved with measured spatial room impulse responses in an anechoic chamber using third-order Ambisonic reproduction. The results of the listening test indicate that the mid-frequency, 500 and 1000 Hz, octave-band average of EDT and the average of the 4000and the 8000 Hz octave bands of C80, have the highest sensitivity in the prediction of reverberance and musical clarity, respectively.
Use of Virtual Reality and auralization as a training tool for acoustic practitioners
Authors: Ottley Matthew , Chen Yuxiao
Published: November 2023

Room acoustic qualities for performance spaces are described, including in ISO 3382-1:2009, in objective metrics such as reverberance, clarity (C80), early lateral energy fraction (JLF) or late lateral sound level (LJ). For acoustic practitioners, an understanding of these parameters and their subjective perception in venues is necessary to describe existing acoustic conditions and carry out acoustic designs of venues. Gaining practical experience of venues to understand the changes in acoustic qualities can be difficult for various reasons. Virtual Reality (VR) technology, combined with auralization from 3-D room impulse responses, generated by computer acoustic modeling of virtual spaces, makes it possible to generate virtual listening experiences to demonstrate room acoustic qualities. This presentation describes the development of a VR training video demonstrating various room acoustic qualities in a virtual concert hall. The video was intended for training of acoustic consultants to recognize and differentiate changes in room acoustic parameters for performance spaces. The VR video presented a number of scenarios where each showed a primary change in one of the qualities, through targeted manipulation of the virtual space. Following deployment of the training video, feedback was taken from users to assess the usefulness of the format for training purposes.
Efficient deep learning-based prediction of acoustic parameters in atrium spaces using BIM files
Authors: Priyadarshinee Prachee , Chen Jer-Ming , BT Balamurali
Published: November 2023

Acoustic simulation tools, although common in the acoustic evaluation of buildings with large atrium space, are costly both in terms of time and resources. This study aims to develop an efficient prediction tool for Reverberation Time (RT) and Sound Pressure Level (SPL) within the atriums using deep learning, with Building Information Modelling (BIM) files as the only input. Initially, a 3-D acoustic simulation model was benchmarked against experimental measurements of RT for an existing building’s atrium, demonstrating an agreement within 15%. Subsequently, BIM files of 60 buildings were used to simulate RT and SPL at various listener locations within their atrium spaces. The BIM files provided essential geometry information, including atrium shape, dimensions, door placements, floor plans, material properties, and sound sources. This dataset was then utilized to train deep learning algorithms, enabling rapid and convenient predictions of RT and SPL for any new building's atrium space. The proposed prediction model serves as a valuable tool for architectural planning and noise regulation during the early design stages. By relying solely on basic building information from the BIM file, this tool obviates the need for time-consuming and computationally expensive simulation software typically used for acoustic evaluations in large atrium spaces.
Detecting free-ranging river dolphin using deep learning based algorithms
Authors: Qiao Gang , Mazhar Suleman , Masud Mamoon , Muhammad Abubakr , Hussain Masroor , Khan Uzma , Arshad Masood
Published: November 2023

Indus river dolphin is an endangered freshwater river dolphin and is included in IUCN red list of endangered species. Canal-strandings is one of the major issues that results in high mortality of the dolphin because the dolphins that are stranded into canals during flood season cannot return to the river during low-water season. As the dolphin uses high frequency echolocation clicks for navigation in muddy river waters, passive acoustic monitoring can be used for detection and localization of the dolphin and can assist in conservation efforts. In this context, we compare performance of variants of deep learning (LSTM) based event detection algorithms for dolphin click detection with conventional algorithms (such as the Teager Energy based click detection and Envelope Derivative Operator based click detection) and analyze the possible scenarios where machine learning based methods may assist in better performance by automatic detection of reflected clicks.
Whales, wind, and whale watching—Uncovering the secret soundscape of Geographe Bay
Authors: Jolliffe Capri D. , McPherson Craig , Wiese Ian
Published: November 2023

Quantifying the acoustic soundscape of an area is an important precursor to understanding the significance of that area from an environmental perspective, as well as providing useful environmental context to inform environmental management. Underwater soundscapes provide important contextual information about the use of that habitat by marine fauna species as well as some of the anthropogenic stressors that may be present. Multi-year acoustic data collected from an underwater acoustic recorder near Cape Naturalist in Geographe Bay was used to characterize the underwater soundscape and complete an initial assessment of cetacean presence. Ambient noise conditions within the Bay were characterized, providing an interim baseline of the ambient noise conditions within the Bay, identifying the biological and anthropogenic contributors to the soundscape. This characterization provided a better understanding of species presence within the Bay and general trends in occurrence, and has also been used to investigate the scale and extent of existing anthropogenic pressures. The information from the monitoring program has been applied to better understand the value of the Geographe Bay area to different species, while at the same time setting a benchmark for ongoing monitoring efforts and providing inputs into detection range modeling to assist in enhancing program design.
Binaural effects and rendering of edge diffraction in geometrical acoustics
Authors: Kirsch Christoph , Ewert Stephan D.
Published: November 2023

Virtual acoustic environments have many applications in entertainment, architectural planning, and hearing research. Geometrical acoustics (GA) is commonly used, offering high computational efficiency by assuming ray-like sound propagation. However, GA does not account for wave-related effects such as edge diffraction, leading to perceptually dissatisfactory results or discontinuities, e.g., when a sound source is occluded. GA can be extended by constructing edge-diffracted sound paths. Recently, we have suggested the universal diffraction filter approximation (UDFA) to model the spectral effects of diffraction from infinite and finite edges and objects composed thereof using highly efficient recursive filters. This contribution investigates how edge diffraction affects the spatial perception of a sound source in conditions where a flat plate occludes the direct sound or produces a reflection. Binaural recordings were obtained with a head and torso simulator at discrete points of a sound source trajectory in the vicinity of a flat plate, including conditions near the incident and reflection shadow boundary. In a listening test, the perceived source location was matched for conditions with and without plate. Differences in localization were observed, and an approach for binaural rendering of simulated diffraction in the GA context is suggested, replicating the localization results obtained for the dummy-head recordings.
Wall-pressure fluctuations in weakly compressible turbulent channel flow
Authors: Wang Meng , Liu Yi , Wang Kan
Published: November 2023

Wall-pressure fluctuations in turbulent wall-bounded flows are detrimental in many applications because they can cause structural vibrations and acoustic radiation. Their spectral behavior at subconvective wavenumbers are to date poorly understood and predicted, particularly in low-Mach-number flows. In this study, compressible direct numerical simulation is employed to elucidate the low-wavenumber behavior of wall-pressure fluctuations in turbulent channel flow and the effect of flow Mach number in the nearly incompressible regime. Simulations are conducted at bulk Mach numbers of 0.4, 0.2, and 0.1, and friction Reynolds number of 180. In addition to the convective ridge that is virtually Mach-number independent, acoustic ridges representing longitudinal and oblique waves are clearly identified in the two-dimensional wavenumber-frequency spectrum. The acoustic peaks are orders of magnitude weaker than the convective peak and decay with flow Mach number, but remain distinctly identifiable even at Mach 0.1. The acoustic energy in the supersonic wavenumber range is significantly enhanced by the onset of the first oblique mode but not much affected by the higher modes. The effect of a small, two-dimensional surface hump is also considered, which is shown to elevate the spectral level of the fluctuating wall pressure in the subconvective wavenumber range by several decades due to acoustic diffraction by the hump. [Work supported by the U.S. Office of Naval Research.]
Acoustic characterization and its relation to POD and SPOD of flow around tandem cylinders
Authors: Zheng Z. C. , Zhou Jerry
Published: November 2023

Flows around two tandem cylinders are simulated using an immersed-boundary method. Cases in the lock-in, transitional and quasi-periodic regimes are investigated. The flowfield is used to provide sources to analyze acoustic pressure at the far field. Both proper orthogonal decomposition (POD) and spectral POD (SPOD) methods are performed for the flowfield to extract flow physics. The relations between the acoustic characterization and the flowfield POD and SPOD are then discussed.
Modal analysis of lithium-ion batteries for estimation of state of charge and state of health
Authors: McGee Tyler , Ezekoye Ofodike A. , Haberman Michael
Published: November 2023

The robustness and safety of battery-operated systems will become critically important as society transitions away from fossil fuels. In the foreseeable future, lithium-ion batteries will be used for high-power, high-capacity applications such as electric vehicles and renewable energy storage. In these applications, which require thousands of cells, existing battery management systems do not monitor the operating conditions of each cell. Variability in temperature and pressure can affect a cell’s state of charge (SOC) or state of health (SOH). This environmental loading coupled with cell-to-cell variability makes SOC/SOH estimation very difficult. Inaccurate measurements of SOC/SOH can reduce the lifespan of battery systems or lead to accidental overcharge and thermal runaway. We present modal analysis as a viable approach to estimate SOC/SOH for electrically cycled cells. Modal tests are performed using laser Doppler vibrometry on 10 Ah Nickel–Manganese–Cobalt pouch cells at 0% and 100% SOC across more than 30 cycles. Changes in the resonance frequencies of the cell are correlated with SOC/SOH to provide an understanding of how the mechanical properties of cell components change as a function of charge level and aging. This work demonstrates that modal analysis may be used as a tool for regular battery maintenance to improve battery safety.
Acoustic signature of sUAS rotors undergoing edgewise forward flight
Authors: Malkki Justin , Yauwenas Yendrew , Doolan Con , Moreau Danielle
Published: November 2023

This presentation shares preliminary experimental results from a new sUAS rotor test rig installed in UNSW’s Anechoic Wind Tunnel (UAT). This new test rig allows acoustic and aerodynamic performance testing of small drone-scale rotor blades under edgewise forward flight conditions at a range of shaft angles. The study of sUAS rotors under edgewise forward flight presents asymmetric inflow to the rotor and unsteady loading on the blades themselves, with different flow conditions experienced by the advancing and retreating rotor blades. This means the acoustic signature of a rotor undergoing edgewise flight is significantly changed compared to static thrust or axial flight conditions of drone rotors or propellers. This presentation aims to outline changes to the acoustic signature of a collection of conventional off the shelf (COTS) rotor and propeller designs between static, axial flight and edgewise flight conditions, coupling this with rotor performance metrics.
Noise assessment and low-noise flight path planning platform for urban air mobility
Authors: Tan Qichen , Li Yuhong , Bao Hongsen , Ma Zhida , Wu Han , Zhou Peng , Zhong Siyang , Zhang Xin
Published: November 2023

The rapidly emerging market of urban air mobility has raised considerable public concern about noise exposure and annoyance, which is likely to limit the development of future aerial transportation. This study presents a comprehensive approach to evaluate the flight noise of an urban air mobility vehicle under various operating conditions and to provide practical flight strategies for low-noise path planning. Two methods with different fidelity levels are considered and compared in evaluating sound sources. The first approach is based on an efficient semi-empirical model to predict the rotor noise and a boundary element method solver to account for the noise scattering from the vehicle fuselage. The second approach is based on high-fidelity computational aeroacoustic simulations considering a practical full-scale urban air mobility vehicle. Then, a Gaussian beam method is used to calculate the far-field sound propagation considering practical physical phenomena in complex environments, including sound refraction attenuation in the atmosphere and reflection from obstacles. A low-noise flight planning strategy is proposed using a heuristic method to optimize the vehicle flight path in realistic urban scenarios. The proposed methods should contribute to future green aerial transportation in low-altitude operations.
Acoustically stimulated electromagnetic method for sensing electric and magnetic properties
Authors: Kaitoh Nobuto , Ikushima Kenji
Published: November 2023

A measurement technique for detecting acoustically induced polarization is introduced. Ultrasonic irradiation can generate alternating electric or magnetic polarization in materials via electromechanical or magnetomechanical coupling, respectively. It follows that electromagnetic fields are often emitted to the surrounding environment when materials are acoustically stimulated. The first harmonic response of the acoustically stimulated electromagnetic (ASEM) field is detected by a resonant antenna tuned to the ultrasound frequency. Ultrasound can temporally modulate the magnetic polarization (magnetization) in ferromagnetic materials, resulting in magnetic imaging and magnetic hysteresis measurements via ultrasonic stimulation. Ultrasonic probing of local magnetic properties gives unique magnetic measurements and is a promising tool in steel inspection. Furthermore, the ASEM response is generated in not only inorganic crystals but also biological tissues such as bones, tendons, and the aortic wall. The response signal is well explained by stress-induced electric polarization of biological tissues, which depends on the crystallinity of fibrous proteins. Therefore, the ASEM method opens possibilities for unique noninvasive sensing in medical fields. In this talk, we will discuss the origin of the ASEM response in various materials and its applications including steel and human measurements.
Microstructure quality assessment for hybrid additive manufactured Ti6Al4V components via ultrasonics
Authors: Sotelo Luz D. , Pratt Cody , Karunakaran Rakeshkumar , Sealy Michael P. , Turner Joseph A.
Published: November 2023

Metal components with functionally organized microstructures for specific applications are emerging thanks to hybrid additive manufacturing (AM). The customization of these high value components accentuates the need for nondestructive methods to characterize their microstructural functional patterns. Nondestructive evaluation (NDE) methods that are economical, fast, energy efficient, and easy to integrate into routine component inspections are preferred. Most importantly, NDE methods must be sensitive to changes in the microstructure such that regions that do not satisfy the design requirements (i.e. out-of-spec regions) can be detected. In this work, ultrasonic NDE methods grounded in diffuse backscatter modeling were used to detect and quantify spatial property variations resulting from a hybrid AM process. The manufacturing process coupled directed energy deposition (DED) with milling in a cyclical manner. These methods were successfully implemented to evaluate the microstructural uniformity of Ti6Al4V samples as well as to make comparisons across an ensemble of samples manufactured with identical parameters. Out-of-spec regions were mapped with respect to the sample geometry on a layer-by-layer basis. The results of this work are expected to inform future NDE strategies for both research and practitioner contexts, and limitations are discussed.
Characterizing high-frequency wave interaction in rigid porous bilayer materials: Insights from acoustic parameter sensitivity analysis
Authors: Sadouki Mustapha , Mahiou Abdelmadjid , Oubadji Roumaissa
Published: November 2023

This study aims to investigate the sensitivity of high-frequency acoustic parameters in rigid air-saturated porous bilayer materials using the equivalent fluid theory. The interaction between the fluid and solid phases of the porous medium incorporates visco-inertial and thermal exchange, characterized by two functions: the dynamic tortuosity α(ω) proposed by Johnson etal. and the dynamic compressibility β(ω) proposed by Allard, refined by Sadouki for the low-frequency domain of ultrasound. Various parameters, including porosity, tortuosity, viscous characteristic length, thermal characteristic length, as well as viscous and thermal shape factors, are examined in this study. A 10% variation in these parameters is considered to assess their impact on the amplitudes of transmitted waves. The findings of this study contribute to a deeper understanding of high-frequency wave behavior in porous bilayer materials. The investigation sheds light on the sensitivity of the parameters and provides valuable insights for the design and optimization of such materials in engineering, technology, and applied sciences.
The effects of noise exposures on complex sound perception by laboratory mice
Authors: Dent Micheal L. , Charlton Payton , Burke Kali , Kobrina Anastasiya , Lauer Amanda
Published: November 2023

Using laboratory mice as models for humans with age-related or noise-induced hearing loss has been a widely accepted practice for many years. However, physiological and reflex-based methodologies are often limited in the stimuli that can be used to measure auditory processing. Behavioral tasks are informative for understanding acuity for ecologically relevant and naturalistic sounds and are more closely matched to measurements of auditory acuity by humans reporting hearing difficulties. Our laboratory has extended the utility of the aging mouse model by (1) assessing hearing across the lifespan using behavioral procedures in awake and trained mice, (2) determining how aging, blasts, and noise exposures affect hearing in mice, and (3) measuring the detection, discrimination, and categorization of complex sounds by mice including ultrasonic vocalizations. We have found differences in auditory acuity of laboratory mice across age, sex, stimulus type, noise exposure, traumatic blasts, and measurement techniques, highlighting the importance of studying complex sound perception in animal models using behavioral approaches. [Work supported by R01-DC012302 and R01-DC016641.]
Mouse models reveal P2X2 receptor-mediated hearing adaptation is an indicator of noise-induced hearing loss vulnerability
Authors: Housley Gary D. , Nadar Ponniah Prathamesh T. , von Wegner Frederic , Cederholm Jennie M.
Published: November 2023

Transgenic mouse models targeting the P2rx2 gene encoding the ATP-gated ion channel P2X2R subunit have revealed a cochlear humoral control mechanism where sustained elevation of background noise drives adaptation of hearing sensitivity over several minutes, requiring hours to reset (evident as “temporary threshold shift” in ABR thresholds, and reduction in DPOAE amplitudes; Housley et al. PNAS 2013, Cederholm et al. Purinergic Signalling 2019, Housley et al. Curr. Opinion. Physiol. 2020). Exposure of P2rx2 knockout (KO) mice to sustained noise (85 dB SPL) fails to elicit the ∼15 dB reduction in ABR thresholds that wildtype (WT) controls demonstrate. While acute hearing sensitivity is maintained, when these P2rx2KO mice are exposed to long-term moderate (75 dB SPL) white noise, they develop high frequency hearing loss not seen in WT controls. This “Purinergic Hearing Adaptation” otoprotection postulate is supported by human studies, where P2RX2 loss of function mutations lead to autosomal dominant progressive hearing loss that is exacerbated with exposure to environmental noise (DFNA41; Yan et al. PNAS 2013). Thus, noise-mediated release of ATP into the cochlear partition drives sustained suppression of the “cochlear amplifier,” supporting cochlear sensori-neural function across a lifetime that complements dynamic medial olivocochlear efferent-based otoprotection.
Comparison of human comfort vibration metrics as applied to Sydney passenger trains
Authors: McMahon Jordan , Duschlbauer Dominik , Miller Aaron
Published: November 2023

This paper discusses train vibration from 400 passenger train passbys measured at two locations in the Sydney metropolitan area with respect to human comfort. The paper focuses on the assessment outcomes as they result from the application of different Standards. The considered Standards include BS 6472, NS 8176, DIN 4150.2, ISO 2631, and the VC curve framework.
Piping riser isolation to prevent transmission of noise and vibration in high rise structures
Authors: Valerio Douglas
Published: November 2023

Preventing the transmission noise and vibration in high rise construction through risers utilizing Spring Isolators is the easiest way to achieve the acoustic criteria for the structure and eliminate weak links (expansion compensators and flexible connectors) in the piping system. We first published literature on the topic in the late 1980s. By utilizing standard calculations for thermal expansion and contraction and selecting a proper anchorage point, isolating risers with spring mounts is simple. This paper is written as a design and installation guideline which addresses concept, design, estimating, and installation.
Source localization in deep water with a towed array from UUV
Authors: Li Zhenglin , Ming Chao , Niu Haiqiang , Xu Linji , Xiao Peng
Published: November 2023

Unmanned Underwater Vehicle (UUV) can work in larger depth. If a towed array applied on UUV, it can detect the acoustics signals from a target in the direct arrival zone with lower transmission loss in deep water. Based on sound field characteristics in deep water, a source detection scheme with multiple UUVs is proposed. The aperture of sonar array is limited by the carrying capacity of UUV. Therefore, a passive aperture extension with sparse Bayesian learning (SBL) is proposed for a moving short array to improve the performance of direction-of-arrival estimation by constructing a larger virtual aperture. The phase correction factors and bearings of different targets are estimated simultaneously by SBL. The experiment results show that the method extends the aperture effectively and obtains higher azimuth resolution and accuracy for the direction-of-arrival (DOA) estimation than the Conventional Beamforming (CBF). The detection of an underwater target by using a towed array from UUV is possible. [Work supported by the National Natural Science Foundation of China, Grant No. U22A2012.]
Cooperative positioning method of underwater autonomous vehicle formation based on extended Kalman filter
Authors: Zhao Jingxu , Zhou Feng , Zhao Chen
Published: November 2023

Autonomous Underwater Vehicles (UAVs) have shown significant potential application value in marine environmental surveillance, development, and utilization of resources. However, due to the complex underwater acoustic channel environment and the relative motion between AUVs, this may lead to heavy-tailed non-Gaussian process noise and measurement noise, leading to increased error and the Extended Kalman Filter (EKF) may fail. In prior studies, we propose a multi-AUV formation hierarchical target location algorithm based on the EKF, which can realize multi-AUV self-localization and stationary target localization. The AUV formation consists of one high-precision piloting AUV and several low-precision following AUVs. The following AUVs are divided into two levels, the reference AUVs and the AUVs to be tested. According to the designed positioning period, the reference AUV receives the position parameters from a high-precision piloting AUV and transmits its own position parameters to the AUV to be measured. Then use the EKF to complete the cooperative position correction of the AUV cluster. In this paper, we will study the influence of heavy-tailed noise on this method and study the EKF based on Huber estimation to improve the antijamming capability.
Practical applications at field environments of sound absorption measurement method using the ensemble averaging technique
Authors: Otsuru Toru , Tomiku Reiji , Okamoto Noriko
Published: November 2023

To construct appropriate boundary conditions for wave-based room acoustics simulations, the authors have proposed a measurement method for sound absorption characteristics, surface impedance, and sound absorption coefficient of materials using the ensemble averaging technique. We have also shown the robustness as well as the reproducibility of the results obtained by the method at various environments. The method consists of two kinds according to sensor types employed so far: i.e., two-microphone and PU-sensor. Generally speaking, the method using a PU-sensor is more advantageous than one using a two-microphone because of its geometrical straightforwardness. However, at various field environments where environmental noise and/or wind blowing exist, the method using a two-microphone is expected to give more favorable results. In this paper, several applicational measurements of the method conducted at field environments using the two sensor types are summarized to show the plausibility of the method.
The impacts of sustainable design practices and cross laminated timber structures on acoustic design
Authors: Wedd Nick , Jimenez Daniel , Cowie Laura
Published: November 2023

More projects in Australia are prioritizing sustainable design practices throughout their building life cycle. Environmental Sustainable Design (ESD) rating tools such as WELL, Green Star, and the Living Building Challenge (LBC) have existed for a decade or more, with some receiving wide adoption in Australia. These rating tools require the assessment of the ingredients, volatile organic compounds (VOCs), and embodied carbon of the materials specified on the project. In addition, cross-laminated timber (CLT) buildings are becoming a more attractive development option due to lower embodied carbon, a reduction in the structural requirements of the foundations, and an increased speed of construction. These sustainable practices are reviewed using a recent project example that combines these recent developments in sustainability: a commercial office fitout in a hybrid steel and cross-laminated timber structure that is targeting WELL Platinum and the Living Building Challenge. The challenges of specifying materials to meet sustainability targets, potential gaps in available products, and the acoustic design challenges of achieving high levels of sound insulation in cross-laminated timber structures are discussed. With a better understanding of sustainable design practices, acoustic designers can improve sustainability outcomes on all projects.
The comprehensive role of acoustic materials in healthy sustainable building design
Authors: Jones Robert
Published: November 2023

In today's world, the acoustic performance of buildings is increasingly evaluated in tandem with its environmental, health, and well-being implications. Design choices related to noise management, speech privacy, speech security, and reverberation time not only influence the occupant's comfort but also impact the environment and the people involved in the construction process. As such, acoustic materials are pivotal in creating sustainable and healthy buildings. Beyond traditional acoustic considerations, broader aspects impacting occupants' experience, such as sensory perception and indoor air quality, must be evaluated. A significant emphasis is placed on biophilic design to foster a connection between the built environment and nature for enhanced well-being. Similarly, the environmental impacts of material choices and the transition to recycled products to reduce the industry's environmental footprint are essential considerations. Acoustic materials have a far-reaching impact on sustainable and healthy building design by addressing occupant comfort, experience, air quality, and the environmental implications of material choices. Moreover, a comprehensive approach to acoustic design and material selection can pave the way for a greener, healthier, and more sustainable future.
Effect of background noise on speech privacy
Authors: Torr Lucy , Balaji Vaishnav
Published: November 2023

There is a need for speech privacy in many building environments, which is often affected by various factors such as human perception, acoustic separation of partitions, and background noise levels. Previous studies have classified speech privacy rating between spaces based on partition separation and internal noise in receiving spaces. However, the typical design process often overlooks a holistic approach to speech privacy. Green buildings, focused on sustainability, have recently gained global attention. They aim to reduce environmental impact while ensuring comfort and health for occupants through energy-efficient HVAC systems, sustainable insulation, and low emissivity glazing. Despite their benefits, energy-efficient HVAC systems can emit minimal noise levels. The low internal noise levels in green buildings can often adversely affect the speech privacy rating between spaces. The Green Building Council of Australia have recently addressed the requirement of speech privacy by introducing the need for minimum internal noise levels in the Green Star Buildings, in addition to the acoustic separation requirements between spaces. This paper aims to investigate the need for minimum internal noise levels to address the requirement of speech privacy holistically rather than addressing acoustic separation and internal noise levels as individual components of acoustic design.
FishSounds: A data-sharing website of global soniferous fish diversity
Authors: Looby Audrey , Cox Kieran , Riera Amalis , Vela Sarah , Bravo Santiago , Rountree Rodney , Juanes Francis , Davies Hailey L. , Spriel Brittnie , Reynolds Laura K. , Martin Charles W.
Published: November 2023

Active fish sound production is geographically and taxonomically widespread—though not homogenous—among fishes, including numerous commercially and recreationally important fisheries species. Despite the ecological importance of fish sounds, their passive acoustic monitoring (PAM) applications, and extensive endeavors to document them, the field of fish bioacoustics has been historically constrained by the lack of an easily accessible, comprehensive inventory of fish sound production. To create such an inventory while simultaneously assessing the global extent of known soniferous fish species, we extracted information from almost 1000 references from the years 1874–2021 to determine that over 900 fish species have been shown to produce active (i.e., intentional) sounds. Our information is collated on the FishSounds website at FishSounds.net along with representative recordings of fish sounds that can be easily searched through and accessed by our users. FishSounds has since launched a new initiative to develop an acoustic catalog for Canadian-specific fisheries species and explore their ecological characteristics, spatial distribution, and taxonomy. The data available on FishSounds can be similarly adapted to meet other regional management needs, facilitate the application of PAM, and aid in the discovery of novel soniferous behaviors across fishes globally.
The search to identify the fish species chorusing along the Southern Australian Continental Shelf
Authors: Hawkins Lauren A. , Saunders Benjamin J. , Erbe Christine , Parnum Iain M. , Wei Chong , McCauley Robert D.
Published: November 2023

Fish produce sound to support life functions. Some species produce choruses, vocalizing continuously over a prolonged period, significantly raising background sound levels within a characteristic frequency band. Fish choruses demonstrate distinctive spatiotemporal patterns, the identification of which can provide information on fish distribution, spawning behaviors, habitat use, and responses to environmental and anthropogenic stressors. Many fish choruses have been reported in Australian waters, yet, very few source species have been identified. Analysis of previously collected acoustic recordings was undertaken to identify fish chorus presence along the southern Australian continental shelf. Three fish chorus types were identified with frequencies centered at approximately 1000, 2300, and 350 Hz. Acoustic recorders and unbaited underwater video recorders were then deployed simultaneously in an attempt to identify the source species of these fish choruses. The 1000 and 2300 Hz fish choruses were detected on the acoustic recordings, corresponding with video recordings of large aggregations of Red Snapper (Centroberyx gerrardi) and Deep Sea Perch (Nemadactylus macropterus). This pilot study was the first step in an attempt to develop an effective methodology that could be used to identify the source species of fish choruses present in offshore environments.
Using quantitative soundscape analyses for coral reef microhabitat discrimination
Authors: Azofeifa Solano Juan Carlos , Erbe Christine , Brooker Rohan , McCauley Robert , Pygas Daniel , Feeney William , Simpson Steve , Nedelec Sophie L , Croxford Evie , Parsons Miles
Published: November 2023

The use of Ocean Sound to describe ecosystems and address ecological questions has increased remarkably during the last decades. The current capacity of recording, storing, and analyzing large amounts of data urges efforts toward developing standards and guidelines to advance underwater soundscape analyses. The development and use of metrics to summarize soundscape attributes have become widespread, but further field-testing and validation are still necessary to identify their ecological relevance resolution. We explore a combination of approaches to determine the performance of ecoacoustic indices and the recently proposed “Soundscape Code” in combination with ecological metrics (habitat and fish assemblage composition) for discrimination between coral reef microhabitats. We collected ecological and acoustic data from Lizard Island (Great Barrier Reef), where we established five transects each with five sampling stations, covering a range of microhabitats from the reef flat zone to the forereef zone, and from high live coral cover to rubble-dominated areas. Conspicuous differences were observed between the soundscapes of the live coral cover and the rubble-dominated areas, demonstrating the potential value of using soundscapes to discriminate between and monitor changes in coral reefs. [Work supported by the BHP-AIMS Australian Coral Reef Resilience Initiative.]
An ultrasonic phantom for cortical and cancellous bone
Authors: Hazelwood Kate E. , Hoffmeister Brent
Published: November 2023

There is interest in developing ultrasonic techniques for diagnosing osteoporosis. Many techniques perform measurements at skeletal sites such as the heel, hip, and spine where the bone tissue consists of a non-porous outer layer of cortical bone that surrounds a porous interior region of cancellous bone. The goal of the present study was to develop an ultrasonic phantom that simulates this tissue configuration. A block of polymer open cell rigid foam (OCRF) was partially embedded in a thin layer of clear epoxy casting resin to create the phantoms. The resulting phantoms were 40mm × 40 mm × 20 mm with one 40 mm × 40 mm face embedded in ∼3mm of resin. Ultrasonic measurements were performed to characterize the speed of sound and attenuation of the resin and the OCRF separately and together, as configured in the phantom. Backscatter measurements were also performed. The resulting specimens can be used to investigate how non-normal incidence of an ultrasonic wave on the bone cortex may produce errors in these measurements.
An acoustic cloaking design considering flow effects by using topology optimization
Authors: Zhu Jingjing , Huang Xun
Published: November 2023

A topology optimization method is utilized to design an acoustic cloak in the presence of background mean flows, highlighting both the scientific significance and practical importance of acoustic invisibility in fluids. This study focuses on understanding the inherent physical mechanism and considering realistic constraints for actual manufacturing, ultimately inspiring the development of an optimized cloak that is available for practical fabrication in the presence of flows. Here, we use the density-based topology optimization to assign specified materials and impose practical constraints on the material allocation to achieve the desired cloaking performance. The optimization problem is then efficiently solved using the gradient-based globally convergent method of moving asymptotes, leveraging the derivative information from the finite element simulation studies of the linearized acoustic potential equation. To validate the proposed method, several numerical simulations are conducted, exploring different frequencies, incident flow speeds, and incident angles of flow. The results confirm the effectiveness and efficiency of the optimization method, expanding the range of applications of the acoustic cloak and contributing to a deepened physical understanding of how it manipulates sound waves in flows.
An analysis of the efficiency and accuracy of applying Huygen's principle to acoustic scattering models
Authors: Espana Aubrey , Kargl Steven , Abawi Ahmad
Published: November 2023

Over the last decade, the Target-in-the-Environment-Response (TIER) model has proven to be an efficient simulation tool for computing the acoustic scattering from axisymmetric objects in an underwater environment. The model functions by first computing the free-field scattered pressure via a high-fidelity Finite Element (FE) computation. The scattered pressure is converted into a scattering amplitude and stored in a look-up table. These scattering amplitudes are used in a fast ray model to compute the acoustic scattering from an object on or embedded in a seafloor, for any vehicle path imaginable. Computing the scattered pressure amplitude for the look-up tables via the FE method is a bottleneck of the computation. For monostatic scattering problems, the look-up table historically sampled the azimuthal angle domain with 1-deg resolution. However, this approach is not efficient in time nor disk space when moving to bistatic scattering situations. Here, we present a more efficient alternative, which is based on application of Huygen’s principle. The results from this method are assessed against the original sampling method and validated against additional high-fidelity models including a hybrid 2-D/3-D FE-Propagation model and a fully 3-D Impedance Matrix method, the latter of which is numerically exact and offers a benchmark solution.