bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental measurements of stress in an acoustic black hole using a laser Doppler vibrometer
Authors: Keys Archie , Cheer Jordan
Published: November 2023

Acoustic Black Holes (ABHs) make use of modifications to a structure to effectively decrease the structural wavespeed, thus increasing the effect of damping material applied in the ABH taper region, resulting in greater vibration attenuation. The most common way in which this is implemented is by gradually reducing the thickness of the structure over a finite interval, to a very thin tip. The focusing effect of the ABH results in high amplitude vibrations occurring in the thin part of the structure, resulting in high stresses and raising significant concerns about fatigue life. This paper presents an experimental assessment of stress in the taper section of an ABH used to terminate a uniform beam, using laser Doppler vibrometer measurements to avoid the mass loading associated with accelerometers or strain gauges. A calculation of stress using Euler–Bernoulli beam theory is then presented, and the validity of this approach is assessed for a thick damping layer applied to a thin structure. A comparison is then made to predictions from a numerical model, in order to validate the results from the experimental measurements.
Measurement of the transmission loss of a rubber hose
Authors: O'Callaghan-Reay Henry , Moore Stephen , Forrest James , Leav Orddom , Howard Carl , Craig Richard , Hunter Morgan
Published: November 2023

Flexible rubber hoses can provide significant attenuation of vibro-acoustic energy in fluid-filled piping systems. The vibro-acoustic performance of rubber hoses can be measured by using a variation of a water-filled impedance tube, using the two-source method, to determine the impedance and transmission loss. This paper presents the test method and results from measurements performed to characterize the vibro-acoustic behavior of a water-filled, 1.5 m length of DN100 fiber reinforced rubber hose, with beaded and flanged terminations, at two pressures. The test results indicated that the rubber hose test specimen achieved a fluid-borne transmission loss of at least 5-10 dB at low frequencies increasing to more than 45 dB at 1kHz.
Study of the underwater soundscape in coastal waters of Hsinta Power Plant
Authors: Fang Yin-Ying , Shih Chen-You , Zhong Ming-Ru , Liu Chia-Yu , Kuo Ting-Jung
Published: November 2023

This study investigates the acoustic environment surrounding the Hsinta power plant, situated in the southwest coastal waters of Taiwan, in proximity to Xingda Port, Yongan Port, Yongan Liquefied Natural Gas Plant, and an artificial reef area via passive acoustics monitoring (PAM) and Automatic Identification System (AIS). Shipping noise (including 45% fishing boats, 20.8% large ships, and 6% tug) generated by inbound and outbound ships significantly affects areas within a range of 2 to 10 km from the study site. Notably, mechanical signals at 60 and 120 Hz, not originating from PAM, have been observed, likely attributed to the Hsinta power plant. Moreover, a distinct series of periodic biological signals within the frequency range of 500 to 800 Hz is consistently recorded near the artificial reef area between 8 p.m. and 10 p.m. Assessing the impact of local ship noise by comparing ambient noise levels below the 100 Hz band before and after the coal shipping seasons (April to September), revealing a difference of 5 to 10 dB. These findings provide valuable insights into the acoustic characteristics of the study area, emphasizing the importance of understanding soundscape dynamics amidst industrial activities and maritime traffic. [Work supported in part by the National Science and Technology Council, Taiwan under Grant NSTC 112-2222-E-130-002-.]
Offshore industry and whales: Pygmy blue whale acoustic behavior and movement patterns in the Otway Basin
Authors: McPherson Craig , Jolliffe Capri , Koessler Matthew W. , Martin Bruce S.
Published: November 2023

The offshore Otway region of Australia is designated as a Biologically Important Area for foraging for blue whales. Understanding the acoustic behavior of blue whales in these foraging grounds will enable an improved understanding of the residency time of individual animals and facilitate improved management of the population. JASCO deployed a directional AMAR G4 for part of the 2020 pygmy blue whale foraging season. The recorded vocalizations, including song and D-calls, have been analyzed in detail to determine bearings, received level, and estimated ranges. Bearings to detected vocalizations were determined using a maximum-likelihood-estimator, with a fluid only propagation model corrected for the layered elastic seafloor used to determine ranges. An analysis of the distribution of different vocalizations across the listening range of the AMAR over time has been conducted and correlated with AIS information from shipping traffic. The results have been used to provide a brief insight into the acoustic behavior and movement patterns of individual pygmy blue whales within the region, furthering our understanding of spatial habitat use in association with commercial shipping lanes and oil and gas operations.
Mechanical disintegration of benign and malignant tumors in ex vivo human prostate tissues using boiling histotripsy
Authors: Khokhlova Vera A. , Rosnitskiy Pavel B. , Tsysar Sergey A. , Karzova Maria M. , Buravkov Sergey V. , Danilova Natalya V. , Malkov Pavel G. , Ponomarchuk Ekaterina , Sapozhnikov Oleg A. , Khokhlova Tatiana , Maxwell Adam D. , Wang Yak-Nam , Kadrev Aleksey V. , Chernyaev Andrey L. , Schade George R.
Published: November 2023

The feasibility of boiling histotripsy (BH) to mechanically liquefy ex vivo human prostate tissue with benign hyperplasia (BPH) and adenocarcinoma (PCa) was assessed. Volumetric BH lesions were generated in fresh tissue samples under B-mode guidance using a 1.5-MHz focused transducer, 10- and 1-ms pulses with 1% duty cycle. Prior to BH exposures, the samples were analyzed using shear wave elastography (SWE) to determine whether their mechanical properties were clinically representative. Completeness and efficiency of ablation for BH lesions were evaluated grossly, histologically, and using B-mode ultrasound. The SWE measured Young’s modulus of the samples was shown to be within the typical range observed clinically. During the exposures, BH-induced hyperechogenic bubbles were visible using B-mode, and post-treatment hypoechoic regions indicated successful tissue fractionation. Gross analysis of the exposed samples with BPH revealed ablation of the targeted tissue inside stiff BPH nodules. The sonications using 1-ms pulses (with 150 pulses-per-focus) were twofold faster comparing to 10-ms (with 30 pulses-per-focus). Histological analysis revealed liquefied lesions containing homogenized cell debris in all BPH samples. A pilot experiment of human PCa tumor fractionation into subcellular fragments was confirmed histologically. [Work supported by R01CA258581, R01DK119310, and RSF 20-12-00145.]
Inactivation of bacteria using different Histotripsy regimes: Toward the treatment of abscesses
Authors: Ambekar Pratik , Wang Yak-Nam , Khokhlova Tatiana , Thomas Gilles , Bruce Matthew , Leotta Daniel , Maxwell Adam D. , Rosnitskii Pavel , Totten Stephanie , Thiel Jeff , Pierson Shelby , Chan Keith , Liles Conrad , Dellinger Evan , Adedipe Adeyinka , Monsky Wayne , Matula Thomas
Published: November 2023

Infected abscesses are defined as localized collections of infected purulent material delineated by a capsule composed of granulation and connective tissue. They can affect any part of the body. Current treatment typically involves antibiotics with either long-term catheter drainage or incision and washout. Given the ubiquitous nature of bacteria and the serious threat of multi-drug resistant strains, abscesses have become a persistent global healthcare problem. Using histotripsy, a potential new noninvasive treatment modality, we have evaluated bacterial inactivation of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) microbes. We have determined the peak negative pressure threshold for inactivation of E. coli in solution for cavitation histotripsy (low cycles, high pulse repetition rate) and boiling histotripsy (high cycles, high pulse repetition rate) for different treatment times. The effect of transducer frequency on bacterial inactivation has also been evaluated. The optimal regimen was used to evaluate the S. aureus inactivation. Bacterial inactivation has also been evaluated in an abscess phantom model. Custom transducers have been developed and evaluated in an animal model for abscesses. [Work supported in part by NIH NIBIB #R01EB019365 and NIAID #R01AR080120.]
Methods for addressing variable turbine operations during wind farm noise compliance monitoring
Authors: Adcock Justin , Delaire Christophe , Guzik Christopher , Mesa Christian
Published: November 2023

Post-construction wind farm noise measurements at dwelling locations are commonly required in Australia to verify compliance with regulatory and contractual noise limits. These measurements are often required as soon as the wind farm has begun operating. However, commissioning issues and electricity network restrictions are a common occurrence during the initial stages of operation. Large wind farm projects are also commonly commissioned in stages. As a result, curtailed modes of operation and shutdowns are a regular occurrence, and large sections of a wind farm may only be operating intermittently. This presents challenges to obtaining noise measurement data that is representative of normal operation of the wind farm and may ultimately limit the conclusions that are able to be reached from measurements during the early stages of operation. To address these challenges, it is necessary to identify and account for any periods when operational noise levels may be lower as a result of turbines being curtailed or shut down. Several methods have been developed for this purpose, and range from simple procedures that remove any data affected by curtailment or shutdown, through to more complex assessments of the magnitude and implications of the uncertainty introduced by variable wind turbine operations. These methods are presented and assessed in this paper with case studies of their application to operational projects.
Coal mining noise in Australia
Authors: Haverkamp Roman , Wassermann John H.
Published: November 2023

Noise pollution in open-cut coal mines in NSW is of great concern and affects large numbers of local communities. The management of noise from coal mines has evolved considerably over the last 30 years, in part due to the significant improvement in mobile fleet sound power levels due to new technology and leading practice noise attenuation components. The mining industry in Australia has also developed an innovative way of managing environmental noise driven by the use of proactive noise management systems. Most large open-cut mining operators in NSW have in recent years adopted and successfully implemented proactive noise management systems to assist with managing noise levels during periods of noise-enhancing meteorological conditions. The system allows the mine operator to prepare and adjust operations to reduce noise levels as far as reasonably and feasibly practical in the event anticipated adverse meteorological conditions are experienced. This paper describes the evolution of the regulatory process, the industry response and the key factors that have shaped the changes.
A review of corona and aeolian noise associated with overhead transmission lines
Authors: Evans Tom , Newitt Lachlan
Published: November 2023

As part of the significant changes occurring in the electricity networks in Australia, there is a need to create significant new transmission infrastructure including in areas relatively close to noise-sensitive land uses. This creates a risk that noise associated with transmissions lines, namely, corona noise and aeolian noise, may occur at a sufficiently high level to result in complaints and compliance risk for the new infrastructure. This paper reviews the mechanisms that can lead to audible corona noise and aeolian noise from transmission lines, as well as information on the nature of the noise including the level and character in the context of legislative requirements that apply in Australia. Guidance is provided on measures to assess and manage the risk associated with it during the design of the infrastructure. Case studies from recent projects are presented where corona noise and aeolian noise has occurred.
Validation of an image source method room acoustics software in a highly reverberant room with a directional impulsive noise source
Authors: Campbell Steven C. , Wall Alan T. , Mobley Frank S. , Bowers Gregory , Reeves Mason A. , Rasband Reese
Published: November 2023

Exposure to impulsive noise sources is common during routine operations military contexts. This type of noise exposure is prevalent in training procedures carried out with small caliber firearms in both indoor and outdoor settings. Typically, hearing protection is required to mitigate hearing damage risk to military personnel. Consequently, proper prescription of hearing protection required bioenvironmental engineers and industrial hygienists to travel and collect data in situ which can be time consuming and expensive. As such, the researchers at the 711th Human Performance Wing of the United States Air Force Research Lab have developed a software named the Shooting Range Impulse Noise Calculator (ShRINC). The ShRINC software provides the capability to simulate high fidelity acoustic levels within indoor and outdoor shooting ranges with directional impulsive noise sources. This is accomplished by leveraging principles from Image Source Room (ISM) based room acoustics and combining them with weapon source models with complicated directivity patterns. In this work, validation will be completed by comparing results collected in a highly reverberant facility with the M4A1 firearm operating blank rounds. An investigation into the proper order for the ISM solver will be analyzed and sound exposure levels between the simulation and measured data will be compared.
Near-field sound propagation and the installation effects of an urban air mobility vehicle
Authors: Li Yuhong , Cantos Sinforiano , Spieser Etienne , Ma Zhida , Zhou Peng , Zhong Siyang
Published: November 2023

A unique challenge of the urban air mobility noise assessment is the configuration-dependent acoustic signature of different designs, of which the installed noise sources must be considered. This work presents a computational aeroacoustics study of a four-rotor urban air mobility vehicle, focusing on near-field propagation considering the installation effects of different vehicle components. The aerodynamic noise sources are computed using the delayed detached eddy simulations, in which the interactional aerodynamics of the rotating propulsion sources and the airframe are addressed. The acoustic propagation effects are calculated by solving Pierce’s equation using the computed mean flow fields and the surface noise sources. The proposed approach is expected to capture the noise scattering from the rotor supports and the fuselage, which cannot be simulated by conventional computational fluid dynamics. The near-field results are then extrapolated to the far field and compared with those from the Ffowcs-Williams and Hawkings acoustic-analogy-based solver. This research provides an integrated aerodynamic and acoustic effects evaluation which should benefit low-noise vehicle design.
An improved inversion method for shale elastic parameters measurement based on ultrasonic resonance spectroscopy
Authors: Li Chao , Wang Peng , Chen Hao , Dai Yuyu
Published: November 2023

The accurate measurement of elastic parameters of shale cores has important guidance for the exploration and development of shale oil and gas. The traditional shale acoustic experiment requires multiple samples from different angles and its preparation process is complex. Resonant Ultrasound Spectroscopy has the advantages of repeatable measurement, high accuracy, and the ability to obtain all elastic parameters from a single small sample. However, the influence of clamping force and measuring angle needs comprehensive analysis to ensure that formant can be measured as many and accurately as possible. This research first conducts sensitivity analysis on the elastic parameters of different shale to guide the experiment. In addition, due to the more complex inversion objective function of the anisotropic shale compared to isotropic samples, the traditional Levenberg–Marquardt method has a strong dependence on the initial value and is prone to falling into local optimal solution. The L-BFGS (limited memory BFGS) method is introduced into the inversion of anisotropic elastic parameters of shale, which can significantly improve the inversion efficiency. Finally, the robustness and reliability of the inversion method are validated through theoretical and experimental measurement results. [Work supported by the National Natural Science Foundation of China (42004117 and 42127807).]
The enduring importance of comparative models for understanding hearing loss
Authors: Lauer Amanda
Published: November 2023

Comparative hearing research has historically focused on diverse organisms’ solutions to sensory problems such as localizing sounds in space, responding to conspecific vocalizations, and using sound for navigation and prey capture. These studies have advanced the bioacoustics and auditory neuroscience fields for many decades, despite decreasing funding for comparative auditory research whose primary intent is not to model human communication disorders. However, animals from across many taxa can experience hearing loss, and to varying degrees, recover their hearing abilities after exposure to damaging events. The genetic diversity of these animals, species-specific variations in evolved protective mechanisms, the rich repertoire of acoustic behaviors, and differences in the capacity for self-repair present important opportunities for discovery of the fundamental mechanisms of normal and disordered hearing. No one species best models humans. It is critical that we support and promote analysis of the physiological, anatomical, and behavioral manifestations of hearing loss using a comparative approach. This presentation will highlight some of the opportunities and challenges in working with diverse species as models of hearing dysfunction.
Investigating the effects of hearing loss in rats and guinea pigs
Authors: Mulders Wilhelmina , Jimena Carlos , Zimdahl Jack W. , Rodger Jennifer , Barry Kristin M.
Published: November 2023

Experimentally induced hearing loss in laboratory animals can lead to subsequent changes in the central nervous system. These central changes following hearing loss may lead to alterations in cognition and anxiety. In our laboratory, rats and guinea pigs are used to study the effects of cochlear trauma with the selected species dependent on the parameters of interest. Guinea pigs’ relatively large and easily accessible cochlea makes the species well suited for cochlear physiological and neural measurements, whereas rats have the advantage of well-established performance on a wide variety of behavioral tests. In a recent study, we investigated whether these well-established tests in rats for stress (open field test; OFT), and learning and memory (novel object recognition; NOR; Morris Water Maze; MWM) could be used in guinea pigs to investigate changes in behavior following conductive hearing loss. Analysis showed that guinea pigs could be trained in the MWM, and showed a similar range of behaviors as described for rats in OFT; however, NOR tests could not be interpreted as most guinea pigs did not interact with the novel objects. Overall, anxiety, spatial learning, and memory were not affected by 8 weeks of conductive hearing loss.
Aging leads to impairment of spatial hearing abilities in the Mongolian Gerbil
Authors: Sergison Matthew D. , Peacock John , Benson Monica A. , Greene Nathaniel T. , Klug Achim , Tollin Daniel J.
Published: November 2023

Aging in humans is known to affect spatial hearing and speech in noise recognition, often even when hearing thresholds are normal. The Mongolian Gerbil (Meriones unguiculatus) can provide a model organism to investigate these changes. We performed auditory brainstem responses (ABRs), prepulse inhibition of the acoustic startle (PPI) behavior, and cochlear histology to assess age-related changes of the gerbil auditory brainstem. Aging (>33month) gerbils showed reduced ABR waveform amplitudes compared to young gerbils (2-10 months). Aging gerbils also show a reduced amplitude of the binaural interaction component (BIC), a biomarker for spatial hearing. However, ABR thresholds were not significantly different between cohorts. Aging gerbils showed impaired performance in our behavior tasks: young gerbils detected shorter gaps in noise and smaller minimum audible angles than aging animals, indicating that aging impairs temporal and spatial hearing abilities. Cochlear histology revealed an increase in cochlear synaptopathy in aging animals, revealing a potential mechanism for age-related dysfunction in the auditory pathway. Taken together, these data reveal structural and physiological changes in the auditory brainstem that underlie spatial hearing deficits in the gerbil. [Work supported by R01-DC017924.]
Investigation of alternative methods for measuring and evaluating airborne sound insulation
Authors: Dong Wayland , Shafer Benjamin M. , Girdhar Sunit , LoVerde John
Published: November 2023

The reproducibility of airborne noise insulation testing is poor, as documented by various interlaboratory studies. This is compounded by the definition of Sound Transmission Class (STC), the dominant single-number rating used in North America, which over-emphasizes the wall performance at and around the 125 Hz third-octave band. Small variations in performance at these frequencies can result in substantial changes in STC rating. To address these concerns, changes to both the measurement method and the single number ratings may be appropriate. For the former, the authors have begun an investigation of measuring the vibro-acoustic characteristics of walls, including measuring the vibration on the surfaces of the separating assembly and the flanking assemblies. This may result in increased precision of sound insulation measurements. For the latter issue, the authors have performed statistical evaluation of published wall sound insulation tests to clarify the effects of idiosyncrasies in the definition of STC and investigated whether different rating methods may better describe the performance of wall assemblies.
The development of the AAAC Guideline for Gymnasium & Exercise Facility Assessment and case study information
Authors: Haydon Richard , Ottley Matthew
Published: November 2023

Association of Australasian Acoustical Consultants (AAAC) member representatives began discussing the need for AAAC guidance on impact noise from gyms in early 2016. This was in the absence of an agreed position or standard assessment criteria. It was identified that in addition to the overall target criteria the Guideline also needed to provide a standardised method to assess and test impacts and to determine compliance as well as guidance on suitable locations for the siting of gyms. This presentation provides an overview of the development of the AAAC Guideline for Gymnasium & Exercise Facility Assessment. The presentation also includes case study information to illustrate the application of the Guideline.
Investigating the impact of tunnel geometry on ground-borne noise and vibration from underground railways
Authors: Timms David , Mackenzie Neil
Published: November 2023

Existing methodologies offer a robust basis for predicting ground-borne noise and vibration effects arising from typical railway tunnel structures constructed using tunnel boring machines. However, the literature offers less clarity on how variations in tunnel geometry—such as those found in mined sections or crossover caverns—may influence these vibration levels. This paper addresses this knowledge gap, employing finite element modeling to conduct a comprehensive parametric study of variations in tunnel geometry. The research objective is to discern the influence these deviations from standard tunnel cross sections have on predictions of ground-borne noise and vibration. The results from this investigation offer valuable insights, challenging the notion that existing methodologies can be universally applied across all tunnel configurations. Our findings underscore the critical role that nuanced tunnel geometries play in shaping ground-borne noise and vibration profiles, emphasizing the need for more granular predictive models that consider these variations. This study is poised to significantly contribute to the understanding and prediction of ground-borne noise and vibration in railway systems, facilitating improved tunnel design, minimizing potential disturbances, and enhancing overall system performance.
Seabed classification using acoustic signals: A decision tree approach
Authors: Rios Diego , Michalopoulou Zoi-Heleni
Published: November 2023

Decision trees are versatile machine learning algorithms that are frequently used in classification and regression tasks. In this work, decision trees are employed as tools for sediment classification using sound waves propagating in the ocean and their behavior and features. We first analyze the structure of received time series at deployed hydrophones, extracting characteristic features (kurtosis and skewness, for example). Feature values then form vectors that are used as input patterns to the trees. A training step is the first stage of the machine learning approach with the trees trained to recognize sediment types based on feature values. The method is subsequently tested on feature vectors obtained from noise-corrupted time series. The performance depends on Signal-to-Noise Ratio values as expected and the method is found to be superior to conventional machine learning approaches. The addition of tools such as principal component analysis as well as spectrogram processing and time-frequency curve fitting further enhances the method. The decision tree technique provides an effective and efficient solution to the problem of sediment classification using acoustic data. [Work supported by ONR.]
Waveguide invariant navigation of an autonomous underwater vehicle
Authors: Jang Junsu , Meyer Florian
Published: November 2023

Reliable navigation of an autonomous underwater vehicle (AUV) remains a challenge due to the unavailability of a global positioning system underwater. However, the self-localization uncertainty of an AUV with an acoustic receiver can potentially be reduced by leveraging passive acoustic ranging techniques. In particular, in shallow water, the range between an acoustic source and a passive receiver can be estimated using the waveguide invariant. In this work, we develop a sequential Bayes navigation filter that fuses passive recordings of an acoustic source with the measurements of an inertial sensor. The acoustic source can either be cooperative or a source of opportunity, e.g., a container ship. Using particle-based processing, our filter can either estimate the waveguide invariant or the AUV position by making use of a detailed nonlinear statistical model of the received signal. If the position of the AUV is accurately known, e.g., in the beginning of the AUV’s mission, the waveguide invariant can be estimated. Alternatively, assuming that accurate waveguide invariant information is available, range information can be obtained and used to improve the estimate of the AUV’s position. The navigation capability provided by the proposed sequential Bayes filter is demonstrated using simulated and real data.
Machine learning transmission loss simulations in complex undersea environments with range-dependent bathymetry
Authors: McCarthy Ryan A. , Sarkar Jit , Merrifield Sophia , Bednar Ryan , Ung Derek , Nager Andrew , Brooks Charles , Terrill Eric
Published: November 2023

Range-dependent bathymetric variability introduces diverse scattering and multipath that can impact optimal acoustic communication ranges, and will impact autonomous underwater vehicle (AUV) operations. We are working towards building a sound-aware framework in which the AUV has knowledge of the transmission environment and can exploit or react with intended outcomes. Prior knowledge of the environment coupled with acoustic propagation modeling on-board AUVs can improve sound-awareness of a vehicle but is computationally intensive, and costly from a power-budget perspective. This work addresses the computational burden by training a machine learning (ML) model to interpret range-dependent acoustic propagation through environmental inputs to predict transmission loss (TL) from the ray tracing model, BELLHOP. A decision tree model is trained to predict locations in range and depth of acceptable TL using feature representations to reduce bathymetric information within a region. Models are trained and tested with TL field realizations for acoustic communications at 10 and 25 kHz for environments with varying bathymetry at ranges up to 3 km through BELLHOP. We present simulations and results from field experiments performed off the coast of Southern California. The communication paths are between a surface vehicle (Liquid Robotics Waveglider, Herdon, VA) and an AUV (REMUS UUV, Huntington Ingalls, Falmouth, MA). Results for model predictions and collected field data will be discussed.
Floors of Heaven: A case study of an underwater acoustic soundscape for recreational purposes
Authors: Castro Daniel , Gleeson Sophie
Published: November 2023

This paper presents a case study of an underwater music piece titled “Floors of Heaven” by British artist Leon Vynehall. This installation was delivered in a swimming pool as part of the Mona Foma 2023 festival, representing an example of the use of soundscapes as a means of artistic expression. The study delves into contemporary trends in soundscapes, with a focus on their utilization as a recreational tool, as the writers observe the growing interest in creating immersive and experiential art installations that engage the viewer on a sensory and emotional level. Subsequently, the paper discusses how soundscapes can be delivered in underwater environments, which present unique challenges in terms of acoustics, sound propagation, and environmental risk factors such as hearing damage. The technical considerations involved in creating an underwater sound installation, including the use of hydrophones and underwater speakers, and the importance of selecting appropriate hardware to achieve acceptable noise levels underwater, are thoroughly described. The case study of “Floors of Heaven,” which uses a combination of field recordings and synthesized sounds to explore themes of ecological collapse and the impact of human activity on underwater environments, is then presented.
Numerical investigation of shipping noise in the Red Sea
Authors: Larayedh Rihab , Krokos George , Cornuelle Bruce , Hoteit Ibrahim
Published: November 2023

Underwater noise pollution is a significant environmental issue that can have detrimental effects on marine ecosystems. One of the main sources of underwater noise pollution is ship traffic, which has been shown to negatively impact marine animals by masking communication signals and altering their behaviors. This study represents the first comprehensive analysis of underwater ship noise in the Red Sea. It aims to generate noise maps of ships sailing through the main shipping lane in the Red Sea. The Range-dependentAcoustic Model (RAM), incorporating anthropogenic and environmental inputs, was utilized to predict maps of underwater ship noises. The application of RAM yielded maps showcasing the spatial and temporal distribution of underwater ship noise in the Red Sea, providing valuable insights for policy makers and facilitating targeted mitigation efforts, with implications for future research on the impacts of underwater noise pollution on marine life.
A method for evaluating the spatial uniformity of sound pressure in a small room by using power spectra at fewer measurement points
Authors: Suzuki Ryoichi , Hoshi Kazuma , Hanyu Toshiki
Published: November 2023

Sound pressure levels in low frequencies vary greatly depending on a measurement point, especially in a small room. The standard deviation of the spatial distribution of sound pressure level (σSPL) is used as one of the parameters to evaluate the spatial uniformity of sound pressure. However, many measurement points are required for an accurate evaluation using σSPL. In this study, we investigate a method for evaluating the spatial uniformity with fewer points. We had proposed the frequency-domain coefficient of variation (FCV) to evaluate the diffuseness of a sound field focusing on the frequency domain. The FCV is defined as the coefficient of variation of a power spectrum. The lower density of room modes in low frequencies would give large σSPL. Thus, larger FCV should be obtained when larger σSPL due to room modes occur. Generally, the power spectrum is obtained from a room impulse response (RIR). However, the bandwidth of each mode is changed depending on the decay of the RIR, namely, a reverberation time. To obtain the FCV avoiding the change of the bandwidth, the decay of RIR is canceled. The results of numerical simulation showed that the FCV at fewer points can evaluate the spatial uniformity than the σSPL.
An assessment of the effectiveness of acoustic treatments for balconies and open spaces as required by Queensland State Assessment and Referral Agency
Authors: Ayva Burak , Mazur Witold , Wong Samuel , Weyers Beau
Published: November 2023

This study examines the effectiveness of acoustic treatments required to fulfill “Queensland State Assessment and Referral Agency (SARA)” conditions for balconies or private open spaces in apartment units above the ground floor. SARA SDAP State Code 1 Performance and Acceptable Outcome PO42 mandates developers to use a combination of continuous, solid, gap-free structures or balustrades and highly acoustically absorbent material treatments for such locations. The study explores the relevance of SARA conditions to balconies and highlights the absence of specific statistical noise level criteria for upper-floor private open spaces affected by traffic noise from state-controlled roads in Queensland. Furthermore, the Code requires these measures for balconies “adjacent” to state-controlled roads, which DTMR defined to be within 100 m of a state transport corridor and/or infrastructure. To investigate these aspects, computational noise modeling was undertaken to predict and assess the impact of road traffic noise on balconies, considering factors such as diffraction, reflection, and direct noise propagation paths. The study also analyzes the potential benefits of acoustic treatments, which were found to be dependent on sight angles to and distances from state-controlled road. In certain cases, minimal acoustic benefits are observed. It is recommended that there is a shift from prescriptive acoustic requirements to performance-based and building-specific requirements within the SARA framework.
Fixed-station and glider-based passive acoustic monitoring reveals spatiotemporal spawning dynamics of Atlantic cod and their potential interaction with offshore wind energy
Authors: Van Hoeck Rebecca , Rowell Timothy J. , Dean Micah J. , Rice Aaron N. , Van Parijs Sofie M.
Published: November 2023

Atlantic cod, which produce sounds associated with courtship behaviors and are overfished in the US, are potentially vulnerable to disturbance from offshore wind energy (OWE) construction and operation during their spawning period. We used a combination of fixed-station and glider-based passive acoustic monitoring methods to evaluate the spatiotemporal spawning dynamics of Atlantic cod and assess their potential interaction with OWE at the extreme southern extent of the species’ range in Southern New England waters of the Western North Atlantic Ocean. Generalized linear modeling of call presence and rates suggests that spawning was concentrated in November and December and was greatest near the new and full moons. The results from both fixed-station and glider-based methods suggest that spawning overlaps with planned OWE construction in time and space. Comparison of these temporal spawning dynamics in Southern New England to analogous PAM data from the geographically separated Massachusetts Bay winter-spawning Atlantic cod subpopulation revealed that the seasonality of inferred spawning was the same between the two regions. By leveraging multiple methods and datasets, this work demonstrates the effectiveness of PAM for understanding spawning phenology of and potential disturbance to an economically important fishery.
Monitoring haddock in the Stellwagen Bank National Marine Sanctuary using passive acoustics
Authors: Mouy Xavier , Rountree Rodney , Brander Matthew , Smith Anne , Van Parijs Sofie M.
Published: November 2023

Haddock (Melanogrammus aeglefinus) are important commercial resources in the western North Atlantic. Their distribution ranges from Newfoundland to North Carolina and are most abundant on Georges Bank and in the Gulf of Maine. Over the course of a decade, the Gulf of Maine warmed faster than 99% of the global ocean and these changes are likely to impact the distribution and reproduction of haddock. It is therefore increasingly important to closely monitor this species and ensure a sustainable fishery. The objective of this study is to monitor the spatial and temporal occurrence of haddock using the sound they produce. We manually annotated over 20 000 haddock calls at five different sites and four different years and used them to train a convolutional neural network that can automatically detect haddock calls in acoustic recordings. The detector was then used to analyze several months of passive acoustic data collected in the Stellwagen Bank National Marine Sanctuary. The analysis revealed that haddock calls were mostly detected during the spawning season (January to March) but were also detected as late as August. We discuss how passive acoustics can complement existing monitoring methods and support the management of this commercially and ecologically important species.
The marine fish Terapon theraps calling in tropical Australia
Authors: McCauley Robert , Cato Douglas H.
Published: November 2023

Calling by fish of the family Terapontidae, primarily Terapon theraps, is a dominant component of sea noise recorded in northern Australian tropical coastal waters. These fish produce nightly choruses over a few hours at frequencies from 50 Hz to a few kilohertz, with spectral peaks up to 30 dB above background. Choruses are heard over muddy bottoms <30 m depth. The two commonly heard calls range from 73–260 ms in length and comprised 11–21 pulses with repetition rates of 87–121 Hz. Calls were produced by muscle action on a two chambered swim bladder, and differed by muscle contraction rates, damping, and possibly the opening state of a sphincter separating chambers. Swimbladder carrier frequencies varied from 570–1465 Hz. Source levels varied from 141–154 dB re 1 mPa @ 1 m. Heavily damped alarm calls were sometimes heard. Chorusing fish schools were up to 2 km across although they were diffuse and actively calling fish extended beyond this region. A chorus could be detected out to 8 km from its center, well beyond the detection range of an individual call. Choruses may advertise school location during spawning, be used for mate attraction or mediate gamete release in dark turbid waters.
Comparison of deep learning algorithms for quantitative diagnosis of fatty liver using multidimensional-moments heatmaps
Authors: Isshiki Akiho , Okazaki Daisuke , Fujiwara KIsako , Kondo Takayuki , Yoshida Kenji , Yamaguchi Tadashi , Hirata Shinnosuke
Published: November 2023

Non-alcoholic fatty liver disease (NAFLD) carries a high risk of progressing to non-alcoholic steatohepatitis (NASH), cirrhosis, and hepatocellular carcinoma. Therefore, the quantitative diagnosis of NAFLD, i.e., determining hepatic fat deposition, is desired during ultrasound inspection. It is known that the deposition of fat droplets within hepatocytes increases the attenuation in ultrasound images. Because the texture of the attenuated ultrasound image becomes a homogeneous speckle, the probability density function of the echo envelopes can be approximated by a Rayleigh distribution. The diagnosis methods of NAFLD using echo-envelope statistics of ultrasound images have been reported. In this study, we focus on the distribution and variance of echo-envelope statistics and propose a new diagnosis method to analysis the characteristics of echo-envelope statistics using a deep learning algorithm (DLA). In the proposed method, first- and third-order moments as echo-envelope statistics are calculated at each pixel in the ultrasound image. Then, the heatmap is formed from the distributions of both moments in each region of interest within the liver. The heatmaps are classified into the stages of fatty liver using DLA such as a convolutional neural network or a vision transformer. In this presentation, a comparative study on the accuracies by various DLA are reported.
Ultrasonic properties of fresh and formalin fixed brain tissue
Authors: Bay Amalia M. , Jenson Grant R. , Hoffmeister Brent , Labuda Cecille , Viano Ann , Hazelwood Kate E. , Myat Phyu Sin M. , Lawler Blake
Published: November 2023

Recent advances in transcranial ultrasound have generated increased interest in the ultrasonic properties of brain. For in vitro laboratory studies of brain tissue, it is convenient to use specimens preserved by formalin fixation. The goal of the present study was to investigate the effect of formalin fixation on the ultrasonic properties of brain. 1-cm thick slices of tissue were prepared from 9 bovine brains. A total of 28 slices from two anatomic planes (16 sagittal, 12 coronal) were studied. Tissue specimens were scanned in phosphate buffered saline at room temperature with a 5 MHz transducer. Scans were performed on fresh tissue and repeated one month after formalin fixation. The speed of sound (SOS) and frequency slope of attenuation (FSA) of ultrasonic pulses propagated through the tissue were determined at every measurement site. The measured values were averaged over all sites on all specimens to obtain the following results expressed as mean ± standard deviation. SOS was (1522 ± 3) m/s before fixation and (1538 ± 12) m/s after fixation. FSA was (0.438 ± 0.064) dB/cm/MHz before fixation and (0.493 ± 0.113) dB/cm/MHz after fixation. Thus, formalin fixation produced approximately a 1% increase in SOS and a 13% increase in FSA.
Convolutional neural networks for tracking coalescing waveforms in supersonic jet noise
Authors: Willis William A. , Valdez John A. , Tinney Charles E. , Hamilton Mark F.
Published: November 2023

High-speed schlieren images of the field surrounding a supersonic jet provide a rich database for testing convolutional neural network (CNN) classification methods due to the presence of many waveform structures of interest. One such structure is waveform coalescence, where waves intersect at small angles, which can lead to increased steepening and nonlinear distortion in the jet near field [Willis et al., AIAA Journal (2023)]. Although waves exhibiting coalescence behavior have been identified in narrow field-of-view (FOV) schlieren images, new methods are needed for large FOV images to improve computational efficiency. This presentation will explore methods to track and classify waves observed in large FOV schlieren images as coalescing or noncoalescing using CNNs. Using transfer learning, pretrained networks can be retrained for this problem, with training data obtained from narrow FOV schlieren or from two-dimensional simulated waveforms using the Khokhlov–Zabolotskaya–Kuznetzov (KZK) equation. The impact of model hyperparameters, choice of pretrained network, image scaling, and other factors on the results of waveform classification by the CNN will be explored. [WAW is supported by the ARL:UT Chester M. McKinney Graduate Fellowship in Acoustics.]
Tandem cylinder aeroacoustic sources
Authors: Dixon Rowena , Jiang Chaoyang , de Silva Charitha , Moreau Danielle , Doolan Con
Published: November 2023

Tandem cylinders in turbulent flow are found in aircraft landing gear, chimney stacks, power lines, and bridge piers. The aim of this paper is to present detailed unsteady surface pressure measurements for tandem cylinders. These unsteady surface pressures are the major sources of noise in this important fundamental test case. A series of experiments were conducted in the UNSW anechoic wind tunnel to investigate the sound generation and flow distortion from a downstream cylinder interacting with wake from an upstream cylinder. This wake is highly anisotropic, containing large vortex shedding scales as well as energetic broadband components. The experiments were conducted using PIV (Particle Image Velocimetry) to obtain instantaneous flow fields and remote microphones to capture unsteady surface pressure measurements. Microphones were positioned outside the flow to record far-field noise. The cylinder was rotated to obtain surface pressure around the circumference. The acoustic results for the tandem cylinder case were compared with noise generation from a single cylinder in uniform flow. An increase in both surface pressure and far-field noise was observed in the tonal and broadband components. It was concluded that interaction with the wake of the upstream cylinder significantly increased the unsteady surface pressure of the downstream cylinder.
Serotonin excites medial olivocochlear neurons of the auditory efferent pathway
Authors: Suthakar Kirupa , Weisz Catherine
Published: November 2023

Medial olivocochlear (MOC) efferent neurons are located in the superior olive of the brainstem and form a sound evoked feedback loop that inhibits cochlear amplification via suppression of outer hair cell (OHC) electromotility. MOC neurons putatively receive a diverse range of synaptic input from various auditory and non-auditory brain regions. Given the proposed role of these neurons in context dependent tasks such as selective attention, we are interested in investigating the non-auditory modulation of MOC activity by the neurotransmitter serotonin (5-hydroxytryptamine, 5-HT). We used the ChAT-IRES-Cre;tdTomato mouse model to identify cholinergic MOC neurons in the brainstem. Immunohistochemical data have validated serotonergic terminals in apposition to both retrogradely labeled and genetically identified MOC neurons in mouse. During patch-clamp recordings from MOC neurons, exogenous application of serotonin increased neuron excitability by increasing action potential (AP) firing rate and decreasing both rheobase and AP threshold. Additionally, serotonin reduced the stimulation required to evoke a given AP firing rate in MOC neurons. These data will aid in our understanding of central auditory processing and how factors such as mood and attention are involved in modulating MOC responses in complex listening situations such as in the presence of background noise.