bluuebunny/crossref_metadata_2025 huggingface dataset:
Reviewer Acknowledgements
Authors: Gibbs Nikki
Published: November 2022

Applied Economics and Finance (AEF) would like to acknowledge the following reviewers for their assistance with peer review of manuscripts for this issue. Many authors, regardless of whether AEF publishes their work, appreciate the helpful feedback provided by the reviewers. Their comments and suggestions were of great help to the authors in improving the quality of their papers. Each of the reviewers listed below returned at least one review for this issue.Reviewers for Volume 9, Number 4 Ali Darub Al-Hiyali, University of Anbar, IraqBabacar Seck, University of Bahrain, BahrainFahri ÖZSUNGUR, Adana Science and Technology University, TurkeyIan McFarlane, University of Reading, UKJames Forest, Finance School of Business SUNY New Paltz, USAMagdalena Radulescu, University of Pitesti, RomaniaOmer Allagabo Omer Mustafa, Sudan Academy for Banking and Financial Sciences., SudanRamona Orastean, Lucian Blaga University of Sibiu, Romania  Nikki GibbsEditorial AssistantOn behalf of,The Editorial Board of Applied Economics and FinanceRedfame Publishing9450 SW Gemini Dr. #99416Beaverton, OR 97008, USAURL: http://aef.redfame.com
Smoothed Particle Hydrodynamics Modeling of Electrodeposition and Dendritic Growth Under Migration- and Diffusion-Controlled Mass Transport
Authors: Cannon Andrew , McDaniel James G. , Ryan Emily
Published: November 2022

In many electrochemical processes, the transport of charged species is governed by the Nernst–Planck equation, which includes terms for both diffusion and electrochemical migration. In this work, a multi-physics, multi-species model based on the smoothed particle hydrodynamics (SPH) method is presented to model the Nernst–Planck equation in systems with electrodeposition. Electrodeposition occurs when ions are deposited onto an electrode. These deposits create complex boundary geometries, which can be challenging for numerical methods to resolve. SPH is a particularly effective numerical method for systems with moving and deforming boundaries due to its particle nature. This paper discusses the SPH implementation of the Nernst–Planck equations with electrodeposition and verifies the model with an analytical solution and a numerical integrator. A convergence study of migration and precipitation is presented to illustrate the model’s accuracy, along with comparisons of the deposition growth front to experimental results.
Reparameterization of Two-Dimensional Projectile Motion
Authors: de Sá Neto Olimpio Pereira , Sousa Herbert José Aquino , da Silva Rafael Ferreira
Published: November 2022

We will present a problem-solving method for the dynamics of a projectile that has two perpendicular acceleration vectors through rotation of the axes. This methodology of reparameterizing the two-dimensional system simplifies the speed optimization calculus.
A Simple Classroom Double Pendulum
Authors: Williams Hollis
Published: November 2022

In this article, we construct a very simple double pendulum (the concept of a pendulum should be familiar to all beginning students of classical mechanics). Since a double pendulum has two degrees of freedom, we suggest that this pendulum can be used in the classroom environment to illustrate the concept of normal modes, and we use video software to show that it is possible to observe a normal mode in action. The pendulum as we describe it should be constructable by all students and is much simpler than the similar experimental setups described in the literature.
Sunny with a Chance of Servos: Solar-Powered Arduinos
Authors: Gfroerer Tim , Adenew Michael , Williams Ella
Published: November 2022

The Arduino microcontroller is finding its way into labs throughout undergraduate physics curricula, from introductory courses to a variety of beyond-the-first-year laboratory classes. At Davidson College, we use Arduinos in a gateway STEM course for students who are interested in energy and the environment. Students learn to build simple circuits and write the accompanying Arduino code to control the temperature in solar-powered model buildings. To make the models fully solar powered, the Arduino itself must be powered by the Sun—no batteries allowed! Hence, we replace the 9-V battery that is usually used to power an Arduino with a 13.5 cm × 12.5 cm 9-V solar panel (DFRobot part #FIT0330), which can generate a maximum short-circuit current of approximately 200 mA. We find that the solar panel works well for most tasks, including temperature measurements, liquid-crystal display (LCD) illumination, and SD card module operation, but cannot generate enough power to drive a servo motor, which needs several hundred milliamps. For these situations, a 9-V, 1-F capacitor connected in parallel with the solar panel can store energy during the rest period between brief high-current operations and supplement the solar panel when higher power is required.
Applications of ultrasound image reconstruction using deep learning
Authors: Hyun Dongwoon , Brickson Leandra , Zhuang Louise , Simson Walter A. , Pinton Gianmarco , Dahl Jeremy
Published: November 2022

Deep learning has gained tremendous popularity as a tool for ultrasound beamforming and image reconstruction. In previous work, we trained deep neural networks (DNNs) to estimate the echogenicity of a medium, to improve acoustical and electronic signal-to-noise ratio (SNR) in channel data, and to detect targeted microbubbles nondestructively for real-time ultrasound molecular imaging. Here, we present several advancements to each application. First, we compare the speckle- and noise-reducing performance of DNNs trained with simple linear Field II simulations of photographic images versus that of DNNs trained with full wave finite-difference time domain numerical simulations containing realistic abdominal walls and the resulting image degradation artifacts. We further extend our nondestructive molecular imaging DNN to incorporate spatiotemporal information using an extended simulation study to increase specificity for stationary bound microbubbles and further improve nondestructive molecular imaging.
The impact of COVID on the teenagers’ brain: Changes in brain responses to music
Authors: Yang Jeffrey , Hyun Jungmoon
Published: November 2022

A variety of cognitive- and health-related issues have been documented as post-COVID symptoms. However, it is unknown how COVID has affected young adults’ brain responses to sounds, especially to musical acoustics. The current study compared brain responses to music between teenagers with a history of mild COVID and teenagers without COVID. A total of 16 teenagers, aged 14–17 participated in this ERP (event-related potential) study. Their cortical responses to the changes in six acoustical components (frequency, rhythm, duration, amplitude, location, and timbre) were recorded using 65-channel electrodes in a passive listening paradigm. Preliminary results suggested different brain response patterns between the two groups. The characteristics of group differences vary across the six acoustical changes. Detailed information on six acoustical components will be further discussed. This study's results revealed COVID contracting teenagers’ neuronal changes that may not be noticeable in the activities of daily life, but it alerts the need for longitudinal studies to examine the post-COVID effect on brain functions in the developing population.
Parameterization of voice onset for automatic assessment of Parkinson’s disease
Authors: Arias-Vergara Tomas , Schraut Tobias , Orozco-Arroyave Juan R. , Döllinger Michael
Published: November 2022

Acoustic analysis of Parkinson’s disease (PD) usually focuses on sustained oscillations of the vocal folds; however, the voice onset (transition from the rest state to a saturation value) is often neglected. In this study, we investigated the parameterization of the voice onset for the objective evaluation of PD. 50 PD patients (25 females) and 50 healthy controls (25 females) performed the sustained phonation of the vowels /ah/, /ih/, and /uh/. Three experts listened to the recordings and assessed the dysarthria level according to a modified version of the Frenchay dysarthria assessment scale (mFDA). We extracted the voice onset automatically, considering the time needed for the amplitude envelope of the acoustic signal to go from 10% up to 90% of the maximum value. Then, we computed filter bank features from the voice onset and pitch, loudness, and perturbation features from the sustained phonation. We performed automatic classification and regression analyses using support vector machines. We obtained a classification accuracy of 89% (AUC: 0.93) when we used feature importance analysis to reduce the feature set. In addition, the regression analysis showed a significant correlation (r: 0.583, p-value < 0.001) between the acoustic features and the mFDA scale. These results show the suitability of the voice onset for objective clinical evaluation of PD.
Cochlear implant users show unexpected flexibility when recognizing words in challenging conditions
Authors: Muegge John , McMurray Bob
Published: November 2022

For typical listeners in quiet, lexical access occurs immediately. Multiple candidates are activated at word onset and subsequently updated as the word unfolds. For cochlear Implant (CI) users, this process changes to cope with their degraded input: CI users delay lexical access until a substantial portion of a word is heard, a profile termed ‘wait-and-see’. However, it is unclear whether this profile is adaptive or simply a result of deficient input. We addressed this using a paradigm in which neutral carrier sentences (“now click on the…”) were interrupted by periodic bursts of noise, even as target words were always clean. This expected difficulty condition was compared to trials in which both sentences and targets were in quiet or in noise. We used the Visual World Paradigm to assess the timecourse of lexical access and competition. Relative to normal hearing controls, CI users (N = 22) showed a robust wait-and-see profile in noise, delaying target fixations and reducing competition. In trials where noise was expected but the target was clean, CI users initially showed a wait-and-see response but rapidly recovered to reach quiet-like performance. This indicates that wait-and-see may be adaptive for challenging conditions, providing flexibility as listeners process words in real time.
Acoustics as a guide to welding quality
Authors: Emmanouilidou Dimitra
Published: November 2022

Welding, the process of melting materials with high heat and fusing them during cool-down, is a fabrication technique common across a wide range of industries including construction, automotive, aerospace. Effective monitoring of the welding process is still an open problem. Weld testing and quality control methods require trained experts and specialized equipment and - in the majority - rely on post-welding inspection for defects or irregularities. In this work, we explore the acoustic qualities of welding sounds and their reliability as an automated quality indicator of the welding process. We investigate the most reliable acoustic features for identifying the quality of welding in the presence of environmental interference and factory floor noise, and we show that the sound picked up by a microphone next to the welding station can be sufficient for identifying a bad weld.
Salinity, force chains, and creep in muddy sediments
Authors: Chotiros Nicholas P.
Published: November 2022

The salinity of sediments is not usually measured. Experience with sandy sediments shows that it has no significant effect on the acoustic properties. In muddy sediments, salinity is critical to the skeletal frame, because it causes the clay particles to flocculate, forming an aggregate of larger particles with significant water fraction. It behaves like a granular medium, in which stress is transmitted along random force chains. Mud is known to suffer from creep, and the force chain model fits neatly into creep theory. It may be modeled as a form of stationary creep, which is linear in many respects. No net strain-hardening is involved. The result is a creep model of the skeletal frame that naturally couples into the Biot theory of porous media. It predicts an attenuation that increases linearly with frequency at low frequencies, which is overtaken by viscous attenuation that increases as the second power of frequency and high frequencies. [Work supported by ONR, Ocean Acoustics Program.]
Potential and kinetic energy of underwater noise measured below a passing ship and response to sub-bottom layering
Authors: Dahl Peter H. , Dall'Osto David
Published: November 2022

For underwater sound energy emitted by a passing vessel and received at a relatively steep angles, such as vessel directly overhead, there can be a significant excess in potential acoustic energy relative to kinetic energy with the opposite also occurring. Observations when expressed as a ratio of kinetic to potential energy in decibels are interpretable upon inspection, yielding an estimate of the sensor height above the seabed, and information on properties of the seabed. The effect was studied as part of the recently completed experiment on the New England Mud Patch. The R/V Neil Armstrong underwent controlled transits directly overhead a vector sensor, positioned 1.45 m above the seabed. A model for kinetic and potential energy developed from method of images combined with a layered seabed, is used to invert the data. The low-speed mud-layer is identified along with higher-speed transition layer separating the mud substrate from a sediment basement, with parameters consistent with other recent studies. Similar observations made in Puget Sound are briefly discussed with the higher-impedance seabed identified being consistent with thin Holocene sediments characteristic of region. Both examples illustrate the standing wave features of such data.
A forward-backward filter for estimating mud properties in SBCEX 17
Authors: Michalopoulou Zoi-Heleni , Gerstoft Peter , Rios Diego , Hodgkiss William
Published: November 2022

The goal of SBCEX 17 was to investigate properties of the mud layer at the experiment site. We perform geoacoustic inversion for the mud site, integrating data and estimates obtained on a track of a moving source. The transmitted sound signals were LFM pulses in a mid-frequency range. The sound was received at a vertical array comprising 16 phones. Arrival times of multiple paths were extracted from the received signals using particle filtering and a backward-moving smoother: forward filtering and smoothing were applied to the received signals for the estimation of path arrival times generated by sound interacting with the waveguide. The smoothing step corrected for outliers that provided erroneous geoacoustic estimates for some source positions. The forward-backward filter provided accurate arrival times with a significant uncertainty reduction. The obtained arrival times were linked with a ray tracer and linearization for source localization and estimation of other parameters that affect sound propagation such as water column depth and sound speed. Sediment sound speed and thickness were then computed. Inversion was carried out at every source location within the track; the results were combined into a single set of estimates and corresponding probability density functions. [Work supported by ONR.]
Creating an immersive audio experience at National Sawdust
Authors: Ellison Steve
Published: November 2022

Venues designed to create immersive audio experiences may include adjustable active acoustics and spatial audio mixing. One such venue is National Sawdust in Brooklyn, New York, which has presented many spatial audio events. For one of these, the electronic music duo “Mouse on Mars,” comprised of Jan St. Werner and Andi Thoma, collaborated with the late Jamaican record producer Lee “Scratch” Perry to create an immersive audio experience presented in March 2022. This audio production presented a challenge, as the content was prepared in Berlin and delivered in Brooklyn using audio systems with significantly different loudspeaker configurations. National Sawdust incorporates a Meyer Sound Constellation active acoustic system with 86 small full-range loudspeakers, 16 compact low-frequency loudspeakers, and a left/right PA system. The Berlin studio includes 20 loudspeakers. Audio sources were spatially mixed to the loudspeakers in both systems using an integrated Spacemap System. The workflow used to prepare this concert and the impact of additional production elements, including active acoustics, lighting, seating, and video, are discussed.
Ambient sound directionality and rapid estimation of empirical Green’s functions in a coastal ocean
Authors: Tan Tsu Wei , Godin Oleg A.
Published: November 2022

Noise interferometry offers an opportunity for passive ocean remote sensing through retrieval of empirical Green’s functions (EGFs) from cross-correlations of ambient sound. At ranges of tens of ocean depths, obtaining stable and accurate EGF estimates usually requires noise averaging periods of hours or days. Decreasing the necessary averaging times without compromising the EGF accuracy is critically important for operational applications. Using data acquired in the Shallow Water 2006 experiment on the continental shelf off New Jersey, it has been found that occasionally averaging periods as short as a few minutes are sufficient. The phenomenon is observed for various receiver pairs but does not occur simultaneously in all azimuthal directions. Short averaging periods give EGFs in a broader frequency band and with a richer mode content. These are better suited to monitor physical processes in the water column. The conditions conducive to rapid EGF emergence are studied using in situ temperature measurements, meteorological information, and the acoustic data acquired with a horizontal line array. Strong intermittency is observed in the horizontal directionality of ambient sound. For various receiver pairs, EGFs are found to emerge rapidly when ambient sound directionality favors propagation in the direction from one receiver to the other.
Adaptive variational Hamiltonian Monte Carlo sampling with application to ocean acoustics
Authors: Whiteaker Brian A. , Jenkins William F. , Schmitt Jeremy , Gerstoft Peter
Published: November 2022

The Hamiltonian Monte Carlo (HMC) algorithm is a variant Markov Chain Monte Carlo (MCMC) excelling at sampling high dimensional target distributions. The HMC explores a distribution as a particle trajectory in a Hamiltonian system by augmenting distribution parameters with auxiliary momentum variables. A particle trajectory is numerically integrated from initial point to some distant low-correlation point. Projecting back to parameter space yields a proposal point with high acceptance probability leading to faster exploration of the target distribution. The Leap-frog integrator is commonly used for its volume preservation (symplecticity) and reversibility traits that maintain the detailed balance condition of MCMC. Although effective, Leap-frog has sensitivity to choice of integration step-size and number of integration steps. Poor choices cause slow exploration or bias when regions of the distribution are not explored. Adaptive step methods could remove step size issues and explore regions of a distribution where Leap-frog fails. Existing adaptive methods self-adjust step-size while maintaining symplecticity and reversibility. In this work, we apply adaptive step methods to simulated target distributions and real world ocean acoustic data and compare performance. [Work supported by Office of Naval Research.]
Applications of Bayesian optimization with a Gaussian process surrogate model in ocean acoustics
Authors: Jenkins William F. , Gerstoft Peter
Published: November 2022

In this study, we present a method that samples geoacoustic parameter space with a Bayesian approach that uses a Gaussian process as a surrogate model of the objective function. The objective function is defined as a Bartlett processor whose output measures the match between a received and replica pressure field on a vertical line array. Replica fields are obtained using a normal mode propagation model whose geoacoustic parameters are selected from the parameter search space. The surrogate model represents the posterior on the objective function and is updated with each model evaluation. Optimization is performed with sequential model evaluations, with an acquisition function guiding the next point in parameter space to be evaluated. Various use cases and parameterizations are discussed, including the effects of the choice of acquisition function and covariance function of the Gaussian process. Results indicate that Bayesian optimization using a Gaussian process surrogate model converges rapidly on an approximated optimal solution.
Revision of ANSI S12.7 methods for measurements of Impulse Noise
Authors: McKinley Richard L.
Published: November 2022

ANSI S12.7 Methods For Measurements Of Impulse Noise 1986 (R2006) applies to all kinds of impulsive noise, whether discrete event sources, such as quarry and mining explosions or sonic booms, or from multiple event sources such as pile drivers, riveting, nail guns, or rifle or gun firing. The working has been working on proposed changes to the measurement methods, especially high speed digital waveform recording techniques to improve the accuracy of capturing the peak of the waveform as well as the details of the structure. The presentation will describe the proposed changes to the measurement methods and measurement microphones as well as the applications of the revised standard once it is approved.
Automated detection of dust-devil-induced pressure signatures
Authors: Urtecho Louis , Krishnamoorthy Siddharth , Berg Elizabeth , Silber Elizabeth , Bowman Daniel , Sparks Andrew , Giannone Miro , Martire Leo , Komjathy Attila
Published: November 2022

Dust devils are common on Mars and in Earth’s arid regions. On Mars, studying the dust devil population is important for understanding dust loading of the Martian climate and has important consequences for robotic and future human exploration. Studying dust devils on Mars is difficult due to insufficient spatio-temporal coverage. Our team is analyzing an infrasound dataset encompassing 7 years of data recorded at the Nevada Nuclear Security Site in the Mojave desert, to identify and characterize terrestrial dust devils as analogues for Martian dust devils. However, the size of this long-duration dataset mandates the use of automated techniques for the detection of dust devils.The automated detection scheme that we have developed follows a two-step process. The first step comprises of significance testing in the time-frequency domain using wavelet transforms and an empirical background red noise model. The second step is a correlation-based, template-matching detector, which utilizes the “heartbeat” pressure signal produced by the dust devil convolved with the microbarometer’s impulse response. In this presentation, we will discuss our automated dust devil detection algorithm, error characterization in the identification of signatures using Monte Carlo analysis and the application of the automated detector to the long-term monitoring dataset.
From atmospheric profile statistics to transmission loss statistics
Authors: Waxler Roger M. , Blom Philip S. , Lawal Adedotun , Frazier Garth , Hetzer Claus
Published: November 2022

Infrasound propagation depends critically on the temperature and wind velocity profiles at the time of signal propagation. These vary wildly, showing at best qualitative systematic behavior. It follows that any predictions of signal detection capability are necessarily statistical in nature. One approach is to collect a large number of historical temperature and wind velocity profiles, for a specific time and location, and use this as a sample space from which to generate a statistical model for the atmosphere as a propagation medium. To generate a statistical model for the expected transmission loss one must run a propagation model through a sampling of atmospheric profiles sufficient to reproduce the statistical behavior. The sampling is done using an Empirical Orthogonal Function (EOF) decomposition. The advantages of the use of an EOF decomposition will be discussed and examples from transition zone (ranges less than 100 km) and regional (ranges of several hundreds of kilometers) will be presented. Given a model for the turbulent pressure fluctuation levels near a receiving array, signal detection probability functions can be estimated.
Intelligibility of synthetic words generated by transformation of a sequence of discrete acoustic events into modulation of the vocal tract shape
Authors: Story Brad H. , Bunton Kate
Published: November 2022

Within the paradigm of a recent model of speech production [Story and Bunton, JASA 146(4), 2522–2528], an utterance is specified as a sequence of relative acoustic events along a time axis. These events consist of directional changes of the vocal tract resonance frequencies called resonance deflection patterns (RDPs) that, when associated with a temporal event function, are transformed via acoustic sensitivity functions, into time-varying modulations of the vocal tract shape. RDPs specifying the targeted directional shift of the first three resonances for bilabial, alveolar, and velar consonants would be coded as [−1 −1 −1], [−1 1 1], and [−1 1 −1], respectively. In this study, these RDPs were combined with four vowels (“ih, ae, eh, uh”) to construct a set of 40 American English words (CVCs). A word intelligibility test was conducted in which listeners heard a synthesized target word and were asked to indicate what they heard by choosing a word from a matrix that included the target and seven near-neighbor words. Results indicate listener word recognition was aligned with the RDP settings, suggesting that they are an effective discrete representation of phonetic segments that can be transformed into speech by modulation of the vocal tract shape.
Japanese pitch-accent perception of noise-vocoded sine-wave speech
Authors: Shinohara Yasuaki
Published: November 2022

A previous study has demonstrated that speech intelligibility is improved for a tone language when sine-wave speech is noise-vocoded, because noise-vocoding eliminates the quasi-periodicity of sine-wave speech. This study examined whether identification accuracy of Japanese pitch-accent words increases after sine-wave speech is noise-vocoded. The results showed that the Japanese listeners’ identification accuracy significantly increased, but their discrimination accuracy did not show a significant difference between the sine-wave speech and noise-vocoded sine-wave speech conditions. These results suggest that Japanese listeners can auditorily discriminate minimal-pair words using any acoustic cues in both conditions, but quasi-periodicity is eliminated by noise-vocoding so that the Japanese listeners’ identification accuracy increases in the noise-vocoded sine-wave speech condition. The same results were not observed when another way of noise-vocoding was used in a previous study, suggesting that the quasi-periodicity of sine-wave speech needs to be adequately eliminated by a noise-vocoder to show a significant difference in identification.
Capturing vocal fry: Understanding the acoustic and perceptual differences in elicited and naturally produced vocal fry
Authors: Alexander Jessica , Irons Sarah T.
Published: November 2022

Vocal fry, used frequently by both men and women, is often associated with negative stereotypes of young women. This study examines how different ways of eliciting vocal fry affects acoustic properties as well as listener perceptions of speech. Stimuli in previous studies have been obtained from actors who were presented with obvious examples of fry from media sources and were then instructed to produce speech with vocal fry. This method of eliciting fry may introduce other vocal characteristics that activate stereotypes. We obtained natural stimuli by asking speakers to read passages with no instructions about vocal fry and created a corpus of acoustic and prosodic data about naturalistic fry. We then recorded actors who listened to naturally-produced examples of vocal fry. We compared the acoustic characteristics of low and high fry speech from our naturally-produced utterances, our actors, and stimuli collected by Anderson et al. (2014). Elicited fry (from both studies) differed when compared to naturally-produced fry. Additionally, elicited fry in our study differed from that of Anderson et al on jitter and other measures. The three sets of stimuli were used to replicate and extend Anderson and colleagues’ study on listener perceptions of men and women using vocal fry.
The impact of loss function domain for optimizing ultrasound imaging
Authors: Spainhour Jacob , Becker Stephen , Bottenus Nick
Published: November 2022

The conventional view of ultrasound pulse-echo data—focused sound sent in a direction and bounced back towards the transducer—does not capture the rich information available. REFoCUS beamforming abandons this limitation, combining the ideas of spatially coded excitation and synthetic aperture imaging. Each transmission is an encoding of elements with various weights and time delays, and the multistatic data set (all transmit/receive element pairs) is estimated from the received data. We can, therefore, apply a single focusing operation across different choices of transmit pulse sequencing and ask questions about how to best optimize that sequence.The multistatic data set is a useful mathematical model since it is tied to individual array elements. Several works have used such raw echo data in optimization problems, for instance training neural networks to improve data quality from limited transmissions. However, we have found that the image formation process (e.g., focusing, beamforming) can change the appearance of errors in the data set. Even small errors in the raw data can result in significant image artifacts due to the inherent ill-conditioning of the beamforming operation. We demonstrate improvements in optimization using loss functions defined in the image domain compared to the raw multistatic data.
High-order singular value decomposition of contrast pulsing sequences for improved clutter suppression
Authors: Wahyulaksana Geraldi , Wei Luxi , Voorneveld Jason , de Jong Nico , van der Steen Antonius F. , Vos Hendrik
Published: November 2022

Contrast-enhanced ultrasound is a diagnostic tool used to visualize blood flow in the cardiovascular system. The use of ultrasound contrast agent (microbubbles) in combination with contrast pulsing scheme (CPS) improves the sensitivity and specificity of ultrasound flow imaging by enhancing the signal in the blood compartment. The commonly used CPS are pulse inversion (PI), amplitude modulation (AM), and amplitude-modulated pulse inversion (AMPI). Using differences in phase or amplitude of multiple pulses, the linear tissue clutter signal can be suppressed. However, this process can be degraded by motion or non-linear propagation of the ultrasound wave. These effects cause the cancellation of linear clutter signal to be ineffective We propose using higher-order singular value decomposition (HOSVD) with spatial, temporal, and pulsing dimensions as the input to improve clutter suppression under the conditions of motion and non-linear propagation. We performed systematic in-vitro- experiment emulating these conditions, as well as in-vivo cardiac measurements. The results showed that HOSVD increases the clutter suppression of all the 3 CPS compared to the conventional linear processing. The improvement of clutter reduction could be beneficial to various cardiac evaluation like myocardial perfusion or intra ventricular flow assessment.
Evaluating a modified delay-multiply-and-sum reconstruction algorithm to improve detection of osteochondritis dissecans
Authors: Holmes Philip M. , Chen Kun-Hui , Lee Hyungkyi , Fitzsimmons James , O'Driscoll Shawn , Urban Matthew W.
Published: November 2022

Osteochondritis dissecans (OCD) is a focal joint defect that is prevalent among youth athletes. With the application of medical ultrasound, OCD of the humeral capitellum could be detected earlier and prevent surgery. In this work, we tested a modified Delay-Multiply-and-Sum (DMAS) reconstruction algorithm to evaluate how it affects medical ultrasound’s ability to detect OCD. Starting with the DMAS reconstruction algorithm described by Matrone et al. (2015), we modified the implementation of filtering and envelope detection steps. Delay-and-Sum (DAS), DMAS, and modified DMAS algorithms were tested on phantom and cadaveric models of capitellar OCD. The DMAS and modified DMAS images were histogram matched to the DAS image for quantitative comparison. By taking several profiles across the images of the artificial OCD lesions, we compared the lesion contrast and bone surface clarity produced by each algorithm. We found that the unmodified DMAS algorithm showed little improvement over the DAS algorithm, particularly after histogram matching. The modified DMAS algorithm showed a much greater improvement in the detection of OCD lesions compared to the DMAS algorithm. This modified DMAS algorithm could be used for other bone surface imaging applications. Future work includes evaluating these algorithms in vivo with patients diagnosed with OCD.
Trans-dimensional Inversion in two spatial dimensions for geoacoustic parameters
Authors: Sonnemann Tim , Dettmer Jan , Holland Charles W. , Dosso Stan
Published: November 2022

We test a series of model parametrizations to invert a two-dimensional (2-D) seabed transect going from simple fixed-dimensional to more complex trans-dimensional configurations. Inverting spherical-wave reflection coefficient datasets independently as one-dimensional layered models for a 2-D section is less efficient than applying a more parsimonious 2-D parametrization while also carrying out full uncertainty quantification. We approach the problem by proposing different fixed and dynamically inferred parametrization schemes, and discuss implementation, computational cost and resulting accuracy. We demonstrate the application in geoacoustics using a dataset of 1711 source transmissions recorded on a 32-element linear hydrophone array with both source and array towed by an autonomous underwater vehicle along a 12 km transect on the Malta Plateau in the Mediterranean Sea.
Simultaneous detection and ranging of baleen whale impulsive vocalizations using a temporal convolutional network
Authors: Goldwater Mark , Zitterbart Daniel P. , Wright Dana , Bonnel Julien
Published: November 2022

In shallow-water environments, low-frequency acoustic signals exhibit dispersive propagation due to interactions with the sea surface and seabed. The received signal can then be modeled as a set of propagating modes. Single-hydrophone modal dispersion has been used to range baleen whale vocalizations and estimate shallow-water geoacoustic properties. However, these algorithms require preliminary signal detection and human labor to estimate the modal dispersion. Here, we apply a temporal convolutional network (TCN) to time-frequency representations of baleen whale gunshots (impulsive calls) to simultaneously detect and range them in large single-hydrophone passive acoustic monitoring datasets. The TCN jointly learns ranging and detection by training using both synthetic gunshots simulated across multiple environments/ranges and experimental noise. The synthetic data is informed by only the experimental dataset’s water column depth, sound speed, and density, while other waveguide parameters vary within empirically observed bounds. The method is applied to an experimental North Pacific right whale dataset collected in the Bering Sea using a single hydrophone. To evaluate model performance, 50 calls are manually ranged using a state-of-the-art physics-based inversion method. The TCN closely matches the physics-based range estimations and detects dispersive gunshots among noise-only examples with high precision and recall. [Work supported by the ONR].
What is the safe noise level to prevent noise-induced hearing loss?
Authors: Fink Daniel
Published: November 2022

Noise causes short-term mechanical and chemical changes in the cochlea, transduced into electrical signals transmitted to the brain. Excessive noise exposure overwhelms the cochlea’s ability to reverse these changes, causing noise-induced hearing loss (NIHL). The Centers for Disease Control and Prevention state that NIHL is the only completely preventable type of hearing loss. What is the evidence-based safe noise exposure level to prevent NIHL? The National Institute for Occupational Safety and Health (NIOSH) recommended exposure level (REL), 85 dBA, does not prevent NIHL. Occupational exposures are calculated for 8 hours/day, 240 days/year, for 40 years. To calculate the noise exposure level to prevent NIHL in the public, 70 dB for 24 hours (Leq(24) = 70), the Environmental Protection Agency (EPA) adjusted the REL for 24 hours/day, 365 days/year exposure. The actual safe noise exposure must be lower than 70 dB because 1) the EPA did not adjust for lifetime noise exposure, 2) NIOSH based its REL on limited-frequency pure tone audiometry, an insensitive measure of auditory damage, and 3) non-occupational noise exposure has increased. The safe noise level may be as low as 55 dBA, the effective quiet level required for humans to recover from noise-induced temporary threshold shift.
Urban noise
Authors: Landa Juvanely Y. , Riegel Kimberly A.
Published: November 2022

People in urban areas are exposed to high noise levels, leading to an increased number of health issues. A mobile phone application called Auditive, was developed to allow the user to report health history, sound level annoyance, and record sound levels on their mobile phones. This allows for real-time sound level data to be directly correlated with the annoyance response. The data recorded with the auditive app provides opportunities for researchers to find correlations between noise exposure, health, and annoyance. A major concern with mobile phone recorded noise is the accuracy of the absolute sound levels without calibration. This study is focused on calibrating mobile phones to provide more accurate data. Two methods for calibration were considered. Technique one calibrates, using the same correction for each type of phone. MATLAB was used to generate pink noise at different sound levels to test a variety of iPhone models. The correction for each frequency level ranging from 63 Hz to 8000 Hz, was determined. Technique two calibrated individual phones. We tested consistent sounds that allow Auditive users to calibrate their phones. These two different techniques will be compared, to establish the best way to calibrate different mobile phones.
Updates to global empirical models for infrasonic signal celerity and backazimuth from ground truth data
Authors: Nippress Alexandra , Green David N.
Published: November 2022

Global empirical models for infrasonic signal celerity (the epicentral distance divided by the total travel time) and backazimuth deviation (the difference between the measured and predicted backazimuth assuming great circle propagation), are used for the association of infrasound automatic detections, event location and acoustic propagation simulation validation. Following a previous methodology to develop a regional celerity-range model (Nippress et al., 2014), we developed a software suite for consistent analysis of a global ground truth database, allowing estimation of empirical models for celerity and backazimuth. We observe 304 detections in the 0.32–1.28 Hz passband, with propagation path lengths of between 25 and 6280 km. Models derived from these observations suggest the backazimuth deviation distribution is range-independent, 92% of the detections studied have a deviation ≤ ±5º. However, the celerity model, produced through fitting the travel-times with a linear regression model, is range-dependent. The celerity model bounds are determined using a quantile regression fit to the travel-time residuals, and are consistent with the current understanding of infrasound propagation. At 10 + years since the publication of the last global celerity-range model, this study provides a timely update.UK Ministry of Defence © Crown Owned Copyright 2022/AWE
Standing wave tube for the calibration of acoustic vector sensors
Authors: Martin James S. , Lawrence Andrew , Sabra Karim G.
Published: November 2022

Acoustic vector sensors are useful in a variety of applications as they provide directional information for ambient noise by sensing the acoustic particle motion in addition to the acoustic pressure. Traditionally, the motion sensor is an accelerometer that is calibrated separately from the associated hydrophone. There are certain advantages that can be realized by calibrating the accelerometer and hydrophone concurrently in a standing wave tube at low frequencies. First, since the pressure and acceleration are simply related in this environment both sensors can be calibrated against a single reference hydrophone. Second, the vector sensor can be calibrated along with the suspension that will be used to mount it thereby taking into account any effects of the suspension’s dynamics. Third, the vector sensor is calibrated to the fluid acceleration rather than its own acceleration thereby accounting for any mismatch in its density relative to the fluid as well as the suspension dynamics. And fourth, the phase response of the acceleration output relative to the pressure output is measured in the calibration. This technique was implemented using a travelling wave tube that was developed for other applications and found to be accurate and convenient.
Vector acoustic properties of the underwater sound field from multiple, simultaneously observed ships
Authors: Choice Hanah A. , Dall'Osto David R. , Dahl Peter H.
Published: November 2022

Vector acoustic properties of the underwater sound field simultaneously observed from multiple surface vessels during the recently completed (May–June 2022) experiment on the New England Mud Patch (NEMP) approximately 100 km south of Cape Cod are discussed. The properties, such as bearing, degree of polarization, and other non-dimensional parameters are derived from a 4 by 4 field matrix composed of pressure and 3-component velocity, and a 3 × 3 matrix composed of only velocity components. The measurements were made with two sensing systems, separated by 21 km, referred to as an Intensity Vector Autonomous Recorder (IVAR), and identified as IVAR-1 and IVAR-2. Individual ship CPAs tracks are identified with automated ship identification (AIS) data. In this presentation, the two sources of measured vector acoustic field data combined with the AIS data are exploited to study the effect of interaction of multiple acoustic sources on a received vector field.
An analysis of “speech glimpses” in realistic environments
Authors: Best Virginia , Buchholz Jorg M. , Goverts S. Theo , Colburn H. Steven
Published: November 2022

A great deal of effort is currently going into recreating everyday acoustic environments in laboratories and clinics, with the goal of obtaining more relevant measurements of real-world listening abilities and intervention benefits. Related work is focused on generating naturalistic speech stimuli that capture important features of real conversations, and on estimating real-world signal-to-noise ratios. Here we make use of a framework that brings together all of these approaches to arrive at highly realistic speech-in-noise stimuli. Using ideal time-frequency segregation, we characterized the “speech glimpses” that are available in these real-world stimuli. By speech glimpses, we refer to distributed time-frequency regions in which the speech of interest dominates the acoustic mixture. One goal was to compare the glimpses that are available in highly realistic stimuli to those available in simpler, commonly used, laboratory stimuli. A second goal was to analyze these glimpses in detail, to provide a new perspective on the many sources of disruption that may hinder the understanding of conversational speech. These include masking (which reduces the number of available glimpses) and reverberation (which reduces the quality of glimpses), as well as interactions between sounds that cause distortions of the spatial information present in the target glimpses.
Effect of electric-acoustic cochlear implant stimulation and coding strategies on spatial cues of speech signals in reverberant room
Authors: Asyraf Muhammad A. , Arifianto Dhany
Published: November 2022

The comparison of spatial cues changes in different setups and coding strategies used in cochlear implants (CI) is investigated. In this experiment, we implement three voice coder setups, such as bilateral CI, bimodal CI, and electro-acoustic stimulation (EAS). Two well-known coding strategies are used, which are continuous interleaved sampling (CIS) and spectral peak (SPEAK). Speech signals are convoluted with appropriate binaural room impulse response (BRIR), creating reverberant spatial stimuli. Five different reverberant conditions (including anechoic) were applied to the stimuli. Interaural level and time differences (ILD and ITD) are evaluated objectively and subjectively, and their relationship with the intelligibility of speech is observed. Prior objective evaluation with CIS reveals that clarity (C50) becomes a more important factor in spatial cue change than reverberation time. Vocoded conditions (bilateral CI) show an increment in ILD value (compression has not been implemented yet on the vocoder processing), when the value of ITD gets more different (decreased) from the middle point. Reverberation degrades the intelligibility rate at various rates depending on the C50 value, both in unvocoded and vocoded conditions. In the vocoded condition, decrement on spatial cues was also followed by the decreement on the intelligibility of spatial stimuli.
Cocktail party effect in team sports: A perceptual advantage
Authors: Antony Reethee , Fredo Isabella , Schaedler Emma , Dunne Meghan , Scheinberg Erica , Fazio Stephanie
Published: November 2022

This study focuses on possible perceptual advantage in speech perception in team sports players. The overall aim was to compare the speech perception in team sports persons versus non-team sports persons, in quiet and in noise. Twenty adults including team sports players and non-team sports players performed speech discrimination task and a speech identification task. Natural digitized speech stimuli including /a/-/a/, /a/-/s/, /s/-/a/, /s/-/s/ were presented binaurally at comfortable loudness level in two conditions—in quiet and in background noise. For noise, talker babble was used at a signal-to noise ratio (SNR) of 0. Percent correct scores and reaction times were measured. Statistical analyses included a mixed model ANOVA. Results were considered significant when pi< 0.05. Significant group differences were present between team sports persons versus non-team sports persons specifically for the speech identification task. The team sports persons had higher speech identification scores and faster reaction times relative to non-team sports persons, specifically in noise (p < 0.05), thus illustrating better auditory separation of signal from noise. The findings from this research serve as a frontier to many studies in expanding our knowledge about speech perception and application of auditory training in team sports players.