bluuebunny/crossref_metadata_2025 huggingface dataset:
Deep net classification of drum strike location with non-uniformmembrane tension
Authors: Taylor John R.
Published: November 2023

Tuning inaccuracies in snare drum membranes can cause inconsistent spectro-temporal changes (e.g., timbre differences) exacerbated by drumhead strike location. This experimental study assesses the potential for developing a deep net classifier for strike drum location, using a Non-UniformlyTuned Snare (NUTS) dataset, comprising 12,107 individual snare drum hits recorded in an anechoic chamber. Unique features of this dataset include its substantial size, additional novel features comprising physical attributes of the drum, and a performance-based classification schema. A series of deep net classifiers are trained using Bayesian hyperparameter optimization, on a subset of 8685 strikes of the NUTS dataset, whose acoustic features are extracted at nine different averaged time-windows(23–2000 ms). A comparison is then made against similar models supplemented by domain knowledge of 15 different combinations of non-uniform membrane tension, whose measures are recorded near the sixteen tuning lugs for each strike. Results found above chance model accuracies, and some performance benefits of including the tuning information as domain knowledge between equivalent trials. Shorter window sizes performed worse than longer time windows, and per-class F1-scores suggest complex spectro-temporal time variant changes caused by dis-uniform membrane tension, which could have implications for performers wishing to broaden the sonic capabilities of the instrument.
The emotional characteristics of bass drums, snares, and disengaged snares with different strokes and dynamics
Authors: Huang Zeyu , Song Wenyi , Ma Xiaojuan , Horner Andrew B.
Published: November 2023

Recent research has explored the emotional characteristics of pitched instruments and the voice. This study investigates the emotional characteristics of the unpitched bass drum, snare drum, and disengaged snare drum. The objective is to explore how the choice of instrument, drum strokes (e.g., single stroke and roll), and dynamics influence the perceived emotional characteristics. Listening tests were carried out with 46 participants, who provided absolute judgments on the sounds in terms of Valence and Arousal on a 5-point Likert scale, alongside the presence of 16 emotional categories: Agitated, Angry, Scary, Terrifying, Joyful, Playful, Slapstick, Exciting, Depressing, Spooky, Mysterious, Nervous, Calm, Gentle, Relaxed, and Peaceful. Data from the listening tests were analyzed using linear regression. Overall, the choice of instrument, drum strokes, and dynamics significantly and similarly influenced Arousal, whereas the choice of instrument had a much stronger effect on Valence than the other two. Specifically, the bass drum was strongly correlated with almost all negative emotions and inversely correlated with high-energy positive emotions. The type of drum strokes was relatively strongly correlated with low-energy positive categories and Agitated. Dynamics had a more secondary effect. These findings offer some detailed insights into how specific emotional characteristics are perceived for drums.
An approach to on/off testing for wind farm noise assessment
Authors: Burgemeister Kym A. , Searle Helen , White Jim , Fisher Kai , Gleeson Sophie , Desombre Tristan
Published: November 2023

In Victoria, assessment of operational wind farm noise is usually undertaken using a regression approach based on NZS6808. This adopts a comparison of long-term operational sound level and wind speed measurements with background sound levels measured prior to the construction of the wind energy facility (WEF), taken at sensitive receivers near to the site. Where no background noise levels have been measured or there are changes in the environment that may make background noise levels unrepresentative, it can be difficult to positively demonstrate compliance with required noise limits, and the results can be inconclusive. On/Off testing is described in NZS6808 as an alternative to conducting sound measurements correlated with wind data, and relies on the wind farm being turned off for a short period to allow a short-term background noise level to be determined, against which the “adjacent” operational noise levels can be compared. However, the approach is not documented in detail in NZS6808 and on/off testing is rarely undertaken in Australia. This paper describes a detailed approach that has been adopted for recent on/off testing undertaken at a large WEF in Australia and outlines the key aspects of the testing which are necessary to conduct a meaningful assessment.
Measurements of ship noise using an acoustic camera: A first survey
Authors: Bocanegra Augusto , Borelli Davide , Schenone Corrado
Published: November 2023

While the acoustic impact of harbors is becoming an increasingly important issue, to the point of limiting their growth, the measurement of noise from ships and port operations is still rough. Two of the main problems that are commonly encountered are source overlapping and large distance from the emitting sources. Source overlapping prevents from identifying the specific contribution coming from each acoustic source. The large distance from the emitting sources, for instance the funnel of a ship or the engine of a transtainer crane, makes the measurement inaccurate. By using the acoustic camera, it is possible to tackle these two problems at the same time. Noise measurements can be made with equipment far from noise source, while distinguishing the contribution from each single source emitting within the sound field. The paper demonstrates this enhanced measurement technique through a set of surveys performed inside French and Italian ports. The ship emissions are analyzed through the acoustic camera for ship on the way, maneuvering inside the harbor, and berthed at wharf. The effectiveness of beamforming technique is discussed, investigating the measurements accuracy, their qualitative and quantitative significance, and the possibility to introduce specific measurement standards for ships based on this methodology.
The acoustics of multirotor platforms for urban air mobility
Authors: Tinney Charles , Valdez John , Zhao Irene
Published: November 2023

The sound field of hovering rotors has generated tremendous interest in recent years with the prospect of urban air mobility platforms comprising eVTOL type designs. In this presentation, we will review a number of key advancements that have been made with regard to an understanding of the sound field produced by multirotor systems in hover and how it relates to the aerodynamic performance of the rotor. Much of this work is based on laboratory-scale measurements of different configurations starting with multirotor drones comprising quad-copter, hexacopter, and even octocopter arrangements (Tinney and Sirohi, AIAA J., 2018) followed by stacked corotating rotors (Valdez and Tinney, AIAA J., 2022) where the trade-space based on stacking distance, index and angle and rotor speed are evaluated. Of particular interest is the constructive and destructive interference of sound waves from neighboring rotors which augment the first few fundamental rotor harmonics. Methods for characterizing the first few rotor harmonics based on POD-based Vold-Kalman order tracking filters (Tinney etal., Int. J. Aeroacoust., 2023) is presented as well as methods for collapsing the high frequency rotor broadband noise using a moving source model (Tinney et al., AIAA Paper 2023-3222).
Acoustic effects of drone flights during sudden decelerations
Authors: Treichel Julia , Lieb Teemu Joonas , Volkert Andreas , Foerster Jan
Published: November 2023

With introduction of U-Spaces into European urban airspaces, unmanned aircraft traffic is expected to increase in the coming years. The growing number of unmanned aircraft, common known as drones, raises the question of the noise impact of these vehicles. So far, this new noise source has only been investigated acoustically in a rudimentary way. The German Environment Agency has, therefore, launched a measurement campaign with various small drone models to investigate acoustic effects. Since drone flights must be designed to be safe, a measurement campaign was conducted in which the models performed a full braking maneuver just before the measurement microphone. This is the case for collision avoidance or when strong gusts of wind occur. In addition, binaural measurements were recorded to provide psychoacoustic findings, as these parameters may be related to the degree of annoyance perceived by the public. In this paper, the measurements and results are presented. Noise levels of the overflights arecompared with noise levels of the deceleration maneuvers. In addition, psychoacoustic quantities such as loudness or sharpness are used and compared for both maneuvers. Finally, conclusions are drawn for the evaluation of drone noise, which can be used for future noise regulations or standardization.
Construction of source description database for machine learning analysis
Authors: Mobley Frank S. , Campbell Steven C. , Reeves Mason A.
Published: November 2023

A large set of acoustic measurements were conducted in conjunction with Sinclair Community College Center for UAS Training and Certification at the Flying Pavilion in Dayton, Ohio. Ten aircraft were characterized at multiple altitudes above a circular array placed on the ground. A subset of these data, with two biologic signals, were presented to a sound jury who provided pairwise similarity judgments. These human perception data were organized into a similarity matrix that then passed through a multi-dimensional scaling analysis. The output of the scaling analyses were examined for each subject and the average across the data collection. This dimensional analysis provides a basis for machine learning analysis to determine the salient features.
Cortical bone properties assessment using axially transmitted low frequency (<500 kHz) guided waves
Authors: Chaboty Aubin A. , Nguyen Vu-Hieu , Haiat Guillaume , Belanger Pierre
Published: November 2023

The early diagnosis of osteoporosis through bone quality assessment has been extensively studied in the past decade. Research in axial transmission using ultrasonic guided waves has shown the method to be sensitive to intrinsic properties of long cortical bone. The aim of this work is, therefore, to show the capability of low frequency guided waves to enable the inversion of dispersion curves into bone properties. The proposed inversion scheme relies on dispersion curves simulated using the semi-analytical iso-geometric analysis (SAIGA) method. The model used in simulation comprised a bone phantom plate with a layer of soft tissue attached to the top surface in accordance with experimental bone phantom plates. A proprietary axial transmission multielement ultrasonic transducer specifically designed to excite ultrasonic guided waves under 500 kHz was used for measurements. Acquired data were processed using the 2-D Fast Fourier Transform to extract dispersion curves. The mechanical properties of the bone phantom plates were obtained by minimizing the difference between the experimental and simulated dispersion curves. The inversion was based on the dispersive properties of ultrasonic guided waves as well as their amplitudes. Results show a difference around 5% between the mechanical properties found with the SAIGA based inversion and those provided by the manufacturer of the plates.
Comparison between BS 7385 and DIN 4150 and their suitability for application in high-level vibration impact assessments
Authors: Miller Aaron , Duschlbauer Dominik , Spagnol Joseph
Published: November 2023

In Australia, there are two standards that are regularly applied to determine appropriate cosmetic damage criteria with respect to vibration from external sources: BS 7385-2:1993 and DIN 4150-3 (both the 1999 and 2016 versions). DIN 4150-3 is being increasingly applied by consultants and specified by regulators, primarily due to having more conservative guideline values and secondarily due to containing specific guideline values for structures that are “of great intrinsic value” (i.e., heritage buildings). However, this presents challenges when trying to undertake a high-level or preliminary vibration assessment, where the resonance frequencies of the buildings requiring assessment or the operating frequencies of the proposed construction equipment are not known. Applying the “long-term” guideline values from DIN 4150-3, which only apply in the horizontal plane of the highest floor of the building, complicates these types of assessments and presents practical challenges for vibration monitoring in practice. This paper compares BS 7385-2:1993 and DIN 4150-3 with the aim of clarifying the differences between the two standards and provides commentary on how these standards should be applied for high-level vibration assessments.
Sonar echo detection based on two-dimensional matched filtering and convolutional neural network
Authors: Zhao Meng , Ren Qunyan , Ma Li
Published: November 2023

In underwater acoustics, the performance of sonar echo detection is limited when the echo-to-noise ratio or echo-to-reverberation ratio is low. As an attempt to improve the echo detection rate and maintain a low false alarm rate, a method based on two-dimensional matched filtering (2-D-MF) and convolutional neural network (CNN) is proposed. The 2-D-MF divides the replica signal into multiple sub-replicas, each with different frequency components, and utilizes the sub-replicas to perform the matched filtering individually, obtaining 2-D-MF features that better represent the amplitude-frequency characteristics of the echo signal. The CNN is utilized as an echo detector to extract echo information from the 2-D-MF features and determine the presence of an echo. The proposed method is tested using data collected in the South China Sea, 2021. During the experiment, a transducer transmitted linear frequency modulation (LFM) signals, and a transponder, acting as an analog target, forwarded the LFM signals as echoes. The detection results demonstrate that this method can improve the echo detection rate by approximately 7% while maintaining a constant false alarm rate of 1‰.
Beam-domain deconvolution beamforming algorithm based on compressive sensing
Authors: Huang JianLi , Wang Yu , Gong ZaiXiao , Wang Jun , Wang HaiBin
Published: November 2023

Deconvolution beamforming is often used to improve the azimuth resolution in target detection. However, most traditional deconvolution beamforming algorithms require the array directivity function to be shift-invariant, which are suitable for specific arrays such as linear arrays and circular arrays. A beam-domain deconvolution beamforming method suitable for arbitrary array is proposed based on compressive sensing. First, conventional beamforming is used to obtain several complex beam outputs, then the Sparse Bayesian Learning (SBL) reconstruction algorithm is applied to the beam-domain model to achieve deconvolution of complex beam outputs. The deconvolution process leads to more accurate estimation for the Direction Of Arrival (DOA) for target signals. The proposed method can also effectively reduce the computational complexity of the algorithm by controlling the number of output beams from the conventional beamforming and is applicable for both non coherent and coherent signals. The simulation and experiment results show that the proposed algorithm has azimuth resolution performance comparable to the traditional element-domain SBL beamforming algorithm, and is superior to the conventional beamforming and Minimum Variance Distortionless Response (MVDR) algorithms. When applied to short and dense arrays, the computation complexity of the proposed algorithm is significantly lower than that of the traditional element-domain SBL beamforming algorithm.
An open source acoustic modem for communication between autonomous underwater vehicles
Authors: Zhang Fumin
Published: November 2023

Miniature underwater robots (MUR) are becoming popular for underwater robotics research. Existing acoustic modems are typically designed for larger vehicles, which requires relatively high power and high cost. We present the Bluebuzz, a open source acoustic modem with reduced size and low power consumption aiming for the applications of MURs. We will report the detailed technical solutions and the experimental results collected and presents future improvements. The modems have also been tested to support higher level networking functions among multiple MUR.
Multi-function underwater acoustic networks combining communication, navigation, and sonar
Authors: Brown David A.
Published: November 2023

Autonomous underwater vehicles often have on-board acoustic modems and navigation systems that work in connection with multiple vehicles. These capabilities may be combined or enhanced with using multifunction transducers that transmit communication and navigation information. The use of multimode transducers to produce acoustic spiral waves for communication, navigation and sonar are presented.
Uncrewed undersea vehicle embedded autonomous target recognition in synthetic aperture sonar imagery
Authors: Todd Bryan D. , Rodriguez-Pinto Ivan I. , Sternlicht Daniel D.
Published: November 2023

The opacity of the ocean to electromagnetic signals makes communication with Uncrewed Undersea Vehicles (UUVs) extremely difficult, especially for situations where the vehicle is operating far from its center of command and control, and makes mid-operation data exfiltration for external processing untenable. This leaves operator intervention and control limited necessitating the need for advanced and adaptive autonomy that can create situational awareness from mission data provided by vehicle sensors. Long range high-resolution imagery generated by synthetic aperture sonar (SAS) is a high fidelity data product that can be further processed by both machine learning techniques and traditional image processing techniques to create computer aided detection and classification (CAD/CAC) capabilities to feed that developing autonomy need. This work examines two separate detection and classification pipelines that have been used in parallel to create contact sets that are actionable for onboard decision processes.
Soundscapes from deep-water moored receivers in the vicinity of the New England Seamounts
Authors: Walters Matthew , Godin Oleg A. , Joseph John , Tan Tsu Wei
Published: November 2023

Acoustic noise interferometry in the ocean relies on synchronized measurements of ambient sound at spatially separated points to passively measure the acoustic travel times between receiver locations. A network of four autonomous, moored, near-bottom acoustic receivers were deployed in the vicinity of the New England Seamounts for 52 days as part of the larger New England Seamount Acoustics (NESMA) Pilot experiment. Receiver depths ranged from 2500–4475 m. The moored receivers provided stable observation platforms in a region with highly variable and occasionally strong currents. The noise interferometry network aimed to investigate the feasibility of utilizing passive acoustic remote sensing methods to study a highly dynamic ocean region with complex bathymetry. Strong ocean variability at the experimental site was induced by its proximity to the Gulf Stream. This paper presents the initial analysis of water-depth dependence and intermittency of ambient sound spectra and spectrograms on near-bottom receivers. The relation between the spectral features of ambient sound and ocean dynamics is explored. Additionally, the feasibility of using the onboard Chip Scale Atomic Clocks to synchronize the experimental data and calculate broadband noise cross-correlation functions for each of the receiver pairs is discussed.
Estimation of ambient marine noise levels in New South Wales
Authors: Velasco Marco
Published: November 2023

Marine and offshore infrastructure is increasingly becoming more prominent in NSW resulting in a requirement to investigate the potential behavioral and physiological impacts to marine fauna during construction and operational phases. Typically, detailed modeling is undertaken to compare the predicted underwater noise levels against noise thresholds with limited consideration to the existing ambient noise levels specific to the site. Vessel movements are known to be the primary contributor to ambient underwater noise levels from anthropogenic sources whereas prevailing noise is generally dominated by natural sources such as wind, waves, precipitation, and seismic activity. Underwater noise monitoring of baseline conditions is not always feasible and can also be cost-prohibitive to undertake. Additionally, there is currently limited publicly available underwater noise measurement data along the eastern coastline of NSW, specifically in shallow waters at depths less than 50 m. This study includes simple procedures to allow for preliminary estimates of the key contributors to the marine noise environment in the context of the Eastern coastline of NSW, with the aim of producing maps estimating existing marine noise levels for common descriptors such as SPL(rms) and SEL(24hour).
A report on an anechoic room design using metal wedges
Authors: Maulana Vicky H. , Hermawanto Denny , Sunarko Benjamin , Rusjadi Dodi
Published: November 2023

An anechoic room is important in acoustic measurements to simulate free-field conditions. The room is designed with walls that are covered with wedges that absorb as much sound as possible to eliminate reflections. Conventional wedges are constructed from a high-density sound-absorbing material such as rock wool and attached to a wire frame to maintain the shape of the wedges. However, these wedges are fragile and easily deformed by physical disturbances. In this paper, a design of an anechoic room using metal wedges is presented. Glass wool with a density of 32 kg/m3 is enclosed within a perforated metal casing, which provides durability and resistance to physical disturbances. The wedges are installed in a room with a dimension of 6.17 m × 5.87 m × 4.85 m. It is shown in a performance assessment based on ISO 3745 that wedges are capable of absorbing sound well, thus allowing sound to propagate according to the inverse square law. Additionally, a comparison study of the absorption performance of glass wool wedges compared to metal wedges is discussed with a view to improving the system in the future.
Revision of Sabine's reverberation theory by following a different approach of Eyring's theory
Authors: Hanyu Toshiki
Published: November 2023

The room acoustic theory was established based on Sabine’s reverberation theory. However, in Sabine's theory, the reverberation time does not become zero even if the absolute absorption condition is satisfied. This is considered to be a contradiction of Sabine’s theory, and Eyring revised the reverberation theory to resolve this contradiction. In this study, the theoretical framework for a consistent reverberation theory is first presented. By using this framework, it is shown that Eyring's theory has a contradiction between the sound energy density in the steady state and the energy decay from the steady state, which is absent in Sabine's theory. Based on the proposed theoretical framework, Sabine’s reverberation theory is revised by following a different approach of Eyring's theory. The reverberation time obtained using the revised theory is shorter than that obtained using Sabine's theory and longer than that obtained using Eyring's theory. Finally, computer simulations using the ray-tracing method are performed to verify the revised theory. The average sound pressure levels and reverberation times obtained using the computer simulations are in better agreement with the values calculated using the revised theory compared to those calculated using Sabine's and Eyring's theories.
Ultrasonic backscatter measurements of cancellous bone in the near field of a planar transducer
Authors: Lawler Blake , Hoffmeister Brent , Viano Ann , Mobley Joel
Published: November 2023

Ultrasonic backscatter techniques may be used to detect changes in bone caused by osteoporosis and other diseases. Typical measurement locations include peripheral skeletal sites such as the heel, which may place the interrogated region of bone tissue in the acoustic near field of the transducer. The purpose of this study is to investigate how measurements in the near field of a planar transducer affect backscatter parameters used for ultrasonic bone assessment. Ultrasonic measurements were performed in a water tank using a planar 2.25 MHz transducer. Signals were acquired for five transducer-specimen distances: N/4, N/2, 3N/4, N, and 5N/4 where N is the near-field distance, a location that represents the transition from the near field to far field. Three backscatter parameters previously identified as potentially useful for ultrasonic bone assessment purposes were investigated: AIB, FSAB, and FIAB. All three parameters depended on transducer-specimen distance to varying degrees with FSAB exhibiting the greatest dependence on distance. These results suggest that laboratory studies of bone should evaluate the performance of backscatter parameters using clinically relevant transducer-specimen distances including distances where the ultrasonically interrogated region is in the near field of the transducer.
Comparing in vivo wave-based elastography with ex vivo mechanical testing in porcine vessels
Authors: Capron Charles , Lee Hyoung-Ki , Singh Prabh , Kilari Sreenivasulu , Liu Gang , Tanner Allison , Roy Tuhin , Guddati Murthy N. , Misra Sanjay , Urban Matthew W.
Published: November 2023

Arterial stiffness predicts cardiovascular disease, the leading cause of death worldwide. Ultrasound elastography methods that measure wave velocity have promise for evaluating the stiffness of blood vessels in vivo. However, vessel geometry modulates wave velocity by inducing geometric dispersion. Here, we compare Young's modulus E estimates obtained using in vivo wave velocity measurements and techniques that either do or do not consider geometry to ex vivo reference E values from mechanical testing . An acoustic radiation force was applied to generate propagating waves in the right common carotid artery (N = 9) and external jugular vein (N = 10) of anesthetized pigs. Vessels were imaged with ultrafast ultrasound to measure wave motion. Group velocity cg was estimated from wave motion using a Radon transform. E was estimated from cg using a bulk media assumption which neglects geometry, as well as the Moens–Korteweg equation and a semi-analytical finite element model, which consider geometry. Pigs were euthanized and vessels were excised. Ring-shaped samples were extracted and tested in a uniaxial tension setup to obtain reference E values for comparison with E values obtained from wave-based techniques. Techniques considering geometry exhibited higher correlation with reference E values, underscoring the need to incorporate geometry for accurate vascular elastography assessments.
Evaluation backscattering coefficients of heterogeneous media containing multispecies scatterers and lipids
Authors: Kutsuzawa Hayato , Hirata Shinnosuke , Yoshida Kenji , Franceschini Emilie , Yamaguchi Tadashi
Published: November 2023

Many attempts have been reported to evaluate tissue characterization from echo signals using the backscatter coefficient (BSC) as an indicator. In the evaluation of the BSC of the biological tissues, it is known that the effects of attenuation properties such as scattering attenuation and absorption attenuation, as well as interference between different scatterers, are significant. In this study, the effects of attenuations and interference were verified by evaluating a phantom with high absorption attenuation and a phantom with a mixture of two types of scatterers. Both the reflector method and the reference phantom method were applied to BSC evaluation for these phantoms, and the accuracy of the evaluation was verified. The results suggest that the effect of the acoustic impedance ratio between the scatterer and the surrounding medium tends to be reflected in the accuracy of the evaluation in media with large absorption attenuation. On the other hand, the difference between the mathematical theory and the actual evaluation results was observed due to interference effects. In terms of the accuracy of the evaluation method, the reflector method is effective in the vicinity of the focus, while the reference phantom method is effective in terms of application.
Verification of effect of analytical conditions of shear wave velocity on ability to evaluate microstructure
Authors: Osato Kodai , Oguri Takuma , Kamiyama Naohisa , Hirata Shinnosuke , Yoshida Kenji , Yamaguchi Tadashi
Published: November 2023

In this study, the relationship between the analytical conditions of shear wave velocity (SWV) and the evaluation ability of microstructure were verified by FDTD simulation. By adding acoustic radiation force (ARF) to the left edge of the simulation space, which mimicked various fatty livers with different fat mass, shear waves propagating in the lateral direction were simulated in each liver. SWV was calculated using the time difference calculated by the cross-correlation method from two timewaves laterally located in the simulation. By varying the resolution of the SWV evaluation, the effect of scattering and refraction of shear waves in fat droplets, etc. on the macroscopic shear propagation was evaluated. Although shear waves could be evaluated stably when tracking shear waves at the spatial step (time width) of the clinical device level, the effects of individual fatty substances were strongly indicated when tracking in the microscopic sense of 10 μm (50 ns). When there was a thick fat layer or a sparse muscle layer near the body surface, the irradiation of ARFI did not work as expected and the evaluation accuracy of SWV decreased.
Ultrasonic spectroscopy at 20–80 MHz to evaluate lymph node status during breast conserving surgery
Authors: Doyle Timothy E. , Sanjinez Dolly A. , Butler Audrey P. , Yzaguirre Andrea F. , Wagner Garrett M. , Al-Ghaib Huda A.
Published: November 2023

High-frequency (20–80 MHz) ultrasound was used to evaluate 77 lymph nodes from 38 patients to identify metastatic breast cancer. Lymph nodes were resected during routine breast conserving surgery. Through-transmission point measurements were collected from the resected nodes immediately following surgery using two single-element transducers (50-MHz center frequency, 6.35-mm diameter), a high-frequency ultrasonic pulser-receiver,and a 1-GHz digital oscilloscope. Attenuation and two spectral parameters—peak density and tortuosity—were calculated from the ultrasonic waveforms and power spectra, respectively. Fisher’s exact test was used to optimize the sensitivity and specificity for each parameter separately and for multivariate analyses. A multivariate analysis of peak density versus tortuosity with a cube-root decision boundary produced the most significant results, with an 89.6% accuracy, 100% sensitivity, 88.4% specificity, and p-value of 6.12 × 10−7. Computer simulations and phantom experiments showed that the sensitivity of the spectral parameters to tissue malignancy arises from ultrasonic Mie scattering from cell nuclei and nuclear pleomorphism. The results demonstrate that ultrasonic spectroscopy at 20–80 MHz provides high sensitivity and specificity for malignant lymph nodes in the breast, and has promise as a rapid, intraoperative, and potentially in vivo diagnostic tool for surgeons and a wide range of soft tissue cancers.
High performance calculation of nonlinear wave propagation on GPU for focused ultrasound treatment planning
Authors: Solovchuk Maxim
Published: November 2023

High intensity focused ultrasound (HIFU) is very promising new technology that has many therapeutic application, and among them are the treatment of cancer in different organs without major side effects. Some of the limitations of HIFU are the long treatment time and incomplete ablation. High performance computing can help in this regard. Simulation of nonlinear wave propagation in three dimensional geometry is very time consuming process especially when shocks are presented. In the current work, we are going to present three dimensional parallel solver on GPU. Some examples for the simulation in a patient specific geometry will be also presented. The presented results can be used for the optimization of the treatment. For the validation of the results, ex-vivo and in-vivo experiments have been performed. It has been shown that large volume can be ablated within a short period of time.
Developing methodologies to correlate perceived sound qualities of violins with controlled construction parameters
Authors: Fritz Claudia
Published: November 2023

The holy grail for violin makers is to find correlations between construction parameters and sound qualities. This is challenging for two main reasons: it is difficult to build violins reliably enough to ensure that the change in the sound is indeed a result of the change of construction parameters; when listening to the violins being played, differences seem to be smoothed out by the players who adapt very quickly. Therefore, while players had so far been preferred in our experiments to maximize the ecological validity and take into account the complexity of the interaction between the player and the instrument, we have decided to test whether other methods, which reduce the influence of the player but are quite artificial, may be useful to explore the influence of some construction parameters on the tone. In the context of two sets of violins built with controlled thickness variations of their plates, we will compare the results of listening tests based on real recordings with a player and with a bowing machine as well as synthesized recordings (from the convolution of an excerpt recorded with piezo sensors and radiation measurements in an anechoic chamber) and discuss them in the light of audio descriptors on the recordings and vibroacoustical measurements on the violins.
Models of the player’s interactions with strings
Authors: Evangelista Gianpaolo
Published: November 2023

In the context of physically inspired models for the synthesis, the development of accurate models for the interaction of the player with the instrument plays a fundamental role. Depending on the musical instrument, the palette of possible interactions is generally very broad and includes the coupling of body parts, mechanical objects, and/or devices with various components of the instrument. In this work, we focus on models of the interaction of the player with strings, which include elastoplastic models of the fingers, dynamic models of the bow, the plectrum and the friction of objects such as bottle necks. We consider interactions both at the stimulation side (e.g., plucking or bowing) and at the fingerboard side, where collisions and/or imperfect pressures introduce nonlinear effects. Other possible interactions in less conventional play modes such as those based on rotating motors and electromagnetic stimulation are taken into account in this work. The proposed models do not depend on the specific implementation of the physical model in, e.g., Finite-Difference Time-Domain (FDTD)-based or waveguide-based schemes. While the former class of implementations may produce more accurate results, the latter allows for simplifications and lower computational costs provided that stability can be guaranteed.
What should be in a construction noise monitoring report?
Authors: Clark Laurence
Published: November 2023

Consider a typical scenario taking place across NSW every day: construction on a major infrastructure project. The contractor has predicted the noise impact, monitors noise levels throughout the works, and must reports the results, as required by Regulators. But what should be included in reports of results? There is a general requirement for providing information that is meaningful to the public. But what might be meaningful information to the public is not specified. The reporter needs to use their judgment and act in good faith. Other guidance, including Standards, list records, sometimes extensive, that should be kept. Surprisingly, photographs, or even videos, do not seem to be mentioned. Nor does there seem to be mention of other useful information that can be collected efficiently with an electronic device, such as a mobile phone, which most people now carry. Screenshots of weather information, locations indicated on satellite imagery, distance measurements; videos of noise sources and meter displays; photos of instrument details, location, set up, and calibration can be efficiently recorded. Information that is meaningful to the public can be selected or derived from these records, with more detail for individual monitoring events and summaries for periodic reporting.
Minimizing unavoidable construction noise impacts in urban environments using soundscape masking effects
Authors: Weston Daniel , Jenkin Lance
Published: November 2023

Construction activities in urban environments often generate unavoidable noise impacts that can adversely affect the well-being of a surrounding community. Traditional noise mitigation strategies focus on reducing noise emissions, which may not be entirely feasible due to the nature of construction activities. It is often the case that construction activity needs to be undertaken during evening and night periods due to the need to occupy a road, a rail corridor, or to facilitate utility service provider requirements to work during low demand periods. This, coupled with the increased community sensitivity at night, is then exacerbated by diminishing background noise levels as daytime human activity dissipates. This paper presents an approach for minimizing the adverse effects of residual construction noise by leveraging the masking effects of artificially generated soundscapes to counteract this existing phenomenon. We identify possible sound and level combinations that effectively mask construction noise without creating additional disturbance. A case study compares the impacts of construction noise with and without the implementation of soundscapes to evaluate the effectiveness. The study explores the compatibility of integrating loudspeakers onto lighting-towers, which are already a mandatory requirement for evening and night construction works, to distribute the soundscape to surrounding noise sensitive receivers.
Managing noise and vibration on mega projects in Australia
Authors: Gowen Tracy , Tabacchi Mattia
Published: November 2023

The last decade has seen the emergence of the mega project in Australia, including Sydney Metro, WestConnex, Western Sydney Airport, Cross River Rail, Melbourne Metro, and North East Link Project. These projects provide challenges in the management of noise and vibration due to site constraints, proximity to sensitive receivers and condensed project timelines. While the environmental noise and vibration regulation of these projects can differ from state to state, the design process remains largely the same. This paper looks at noise and vibration design and management on some of Australia’s biggest infrastructure projects. Design considerations include physical mitigation measures such as acoustics sheds, noise barriers, temporary noise barriers or enclosures, and ventilation mitigation. Management measures and development of ongoing management tools are described. Finally, this paper reflects upon the overall noise and vibration outcomes in terms of impacts on the affected communities compared with cost of mitigation.
Comparison of predicted and measured noise levels from major infrastructure construction projects
Authors: Henrys Nicholas , Parker Andrew , Evans Tom , Jurevicius Darren
Published: November 2023

Urbanization has led to major infrastructure projects increasingly being constructed within heavily populated residential areas. Prediction and management of noise impacts associated with construction works is an increasingly important consideration during both the planning and delivery phase of projects. However, accurate prediction of construction noise is often challenging, due to the dynamic nature of infrastructure construction sites, with a large number of mobile and intermittent noise sources. Particularly during the planning phase, there is typically a lack of detailed information required to support accurate noise modeling. Noise predictions are nevertheless relied upon to inform the project team and surrounding community of the expected noise impact of upcoming works and to determine the most appropriate mitigation and management measures to adopt. In this paper, we compare noise levels predicted using a variety of common methods, with attended and unattended noise monitoring results obtained on a number of recent projects.
Application of audio spectrogram transformer machine learning model for audio tagging of construction activities
Authors: Cooper-Woolley Ben , Zhao Sipei
Published: November 2023

Major construction projects are approved based on an Environmental Impact Statement, which includes modeled predictions of noise impacts based on planned program. However, actual on site construction activities can differ significantly from planned works, resulting in modeled acoustic impacts (which have been used to mitigate impacts and inform stakeholders) out of date. A potential solution to this may be the use of machine learning models, to initially classify, and later predict, actual on site activities and commensurate impacts on nearby stakeholder and communities caused by site works. By leveraging emerging lower cost, smaller noise monitoring devices more data can be collected at receivers, and classified to determine the contributing sources of sound. SiteHive has worked with the University of Technology Sydney to design and develop a machine learning model to classify construction works in real-time on site, integrated as part of the SiteHive Hexanode multi-sensor environmental monitoring device. This presentation will showcase the design and development undertaken to date, and highlight results as tested as part of a major works program.
Phase holograms for the three-dimensional patterning of microparticles in a traveling wave field
Authors: Ghanem Mohamed A. , Maxwell Adam D. , Dalecki Diane , Sapozhnikov Oleg A. , Bailey Michael R.
Published: November 2023

Acoustic fields can generate radiation forces that can align particles in patterns. Forces from standing waves pattern particles in three dimensions (3-D) at either nodal or anti-nodal regions. These patterns can be utilized to form 3-D microstructures for applications in tissue engineering or fabrication of layered materials. However, standing waves require more than one transducer or a reflector, which can complicate implementation. Here, we developed a method to suspend and align microspheres using a traveling wave from a single transducer. Acoustic fields were shaped to align polyethylene microspheres mimicking tissue cells in parallel planes along the axis of the transducer. A Bessel-like beam was developed using diffraction theory and an iterative angular spectrum approach were used to design phase holograms to shape pressure fields. Gor’kov potential was used to calculate radiation forces while minimizing the axial forces to create a stable trap. The resulting pressure fields and particle patterns matched predictions with a similarity index >0.92, where 1 is a perfect match. The transverse radiation force was ten times each microsphere’s weight and comparable to the standing wave radiation forces. Next steps are in vivo implementation of cell patterning for tissue engineering. [Work supported by NIH K25-DK132416 and P01-DK043881.]
Characterizing bulk-driven acoustic streaming in air
Authors: Stone Christopher , Croxford Anthony , Azarpeyvand Mahdi , Drinkwater Bruce
Published: November 2023

The time-independent fluid flows induced by the attenuation of acoustic energy known as acoustic streaming have been experimentally measured in air using particle image velocimetry for two high powered ultrasonic transducers. The literature declares that these bulk-driven “Eckart” streaming flows are observed as turbulent jets in the direction of the acoustic wave propagation. The aim of this work is to increase the understanding of the coupling between the acoustic and fluid domains and to validate these well-established theoretical relationships. Langevin horns and focused arrays of parking sensor transducers, which operate at ∼26 and 40 kHz, respectively, and are both capable of producing sound pressure levels of up to 170dB, were used to assess the relationship between the first order acoustic field and the second order streaming velocity field. Streaming velocities of the order of 0.2 and 0.3 m/s were measured for the Langevin horn and the focused array, respectively. Two-step COMSOL Multiphysics models were created for both transducers, first solving the acoustic fields in the frequency domain, then using the results to drive a streaming volume force in a stationary fluid mechanics study. Both laminar and turbulent k-ε fluid mechanics models were compared to the experimental results.
Focus control of a concave ultrasonic gel lens
Authors: Tagashira Kokichi , Harada Yuki , Nakamura Kosuke , Koyama Daisuke
Published: November 2023

Optical image stabilization is a powerful tool for camera devices. This paper investigates a tunable lens using ultrasound and a transparent viscoelastic gel in which the focal point can be controlled in the radial direction. The lens has a simple structure and consists of four piezoelectric ultrasonic transducers, a glass disc, and a transparent silicone gel film. A four-phase drive of the lens at the resonant frequency generates the flexural traveling-wave mode, resulting in changes of the surface profile of the gel by acoustic radiation force. At a resonant frequency of 60.8 kHz, a concave shape was observed on the gel surface, indicating that a concave lens can be fabricated by controlling the driving frequency and the phase difference between the transducers. Optical characteristics of the lens were evaluated by ray tracing. The deformation displacement of the lens surface and the change in focal length increased with the voltage amplitude. The voltage ratio between the four transducers was changed, allowing the center position of the gel deformation and its focal position to be shifted in the radial direction, thus realizing image stabilization functions.
Effect of ultrasonic vibration on the orientation of C2C12 cells
Authors: Hashiguchi Ryohei , Kumeta Masahiro , Koyama Daisuke
Published: November 2023

Control of orientation direction of tissues is important for regenerative medicine techniques. This paper investigates effects of ultrasound vibration on a culture dish on the orientation of myoblast C2C12 cells. A piezoelectric ultrasonic transducer (PZT) was fixed to the bottom of a culture dish. A continuous sinusoidal signal with 10 to 30 Vpp at the resonant frequency of 86kHz was input to the transducer to generate a concentric flexural vibration mode on the bottom surface of the dish. C2C12 cells were cultured on the dish for 2 days under continuous ultrasonic vibration. The ultrasound excitation was then stopped, resulting in the differentiation of the cells into myotube cells through 7 days. The orientation distribution of the cells on the dish was evaluated by spatial Fourier transform in the microscopic images. Compared with the control, the orientation of C2C12 cells was changed significantly under ultrasonication; the concentric pattern of the cell orientation appeared, which corresponds to the concentric vibration mode generated on the bottom of the dish. Larger vibrational amplitude of the dish gave a larger effect on the cell orientation.