bluuebunny/crossref_metadata_2025 huggingface dataset:
A Monte Carlo approach to modelling detection ranges for killer whales in inshore waters of British Columbia, Canada
Authors: Austin Melanie , Mouy Xavier , Yurk Harald , Wladichuk Jennifer
Published: November 2021

Passive underwater listening stations are often used to monitor the presence, distribution and movements of marine mammals. This requires an understanding of the distances at which marine mammal sounds can be detected at a location and at different times given varying ambient noise conditions. Here, we describe a Monte Carlo approach for determining call detection probabilities as a function of distance for networked underwater listening stations deployed by Fisheries and Oceans Canada in the Salish Sea to track endangered Southern Resident Killer Whales. We used ambient sound levels measured in situ, modelled propagation losses determined by two acoustic models, and applied Monte Carlo simulations to capture the variability in call source level and animal depth. Given that only some parts of the call frequency spectrum may be responsible for the maximum detection range, the analysis was carried out independently for consecutive 300 Hz frequency bands. Median detection range estimates ranged from 700 m at the noisiest time and location to 8 km at the quietest. A sensitivity analysis revealed that the frequency distribution of source levels used for the analysis was a major factor affecting detection range results, while differences in propagation losses between summer and winter were less important.
Integrating visual and acoustic observations to build an “intelligent” killer whale movement forecast system
Authors: Joy Ruth , Bergner Steven , Campbell Dave , Dowd Mike , Frazao Fabio , Kirsebom Oliver S. , Nguyen Hong Duc Paul , Padovese Bruno , Randon Marine , Riera Vuibert Amalis , Sakib Sadman , Veirs Scott , veirs val , Wladichuk Jennifer , Yurk Harald
Published: November 2021

Shipping traffic continues to grow in the Salish Sea with considerable marine industrial developments planned for the region. With this comes an increase in the risk of cetaceans being disturbed, harassed, and potentially colliding with commercially operating vessels. One key conservation concern is these waters coincide with designated Critical Habitat for the endangered population of Southern Resident killer whales (SRKW). Monitoring technologies such as hydrophones provide the promise of real-time animal detection and localisation. To use these continuous streams of real-time whale location data, we are developing algorithms that automate acoustic detection and classification of SRKW calls using deep learning models trained on extensive new and updated annotated datasets from the region. We are developing open-source models for pod-level classification, while also differentiating SRKW from other ecotypes and species. We are developing a forecasting system to merge these whale detections with opportunistic visual observations. This is based on sequential data assimilation methods using advanced animal movement models to estimate SRKW pod locations with probabilistic predictions of whale directional movement. These methods will be transformative for shipping by providing forecasting with a lead time of a few hours allowing vessels to adjust their speed or pathway to minimize whale-vessel interactions.
Call repertoire and inferred ecotype presence of killer whales (Orcinus orca) recorded in the southeastern Chukchi Sea
Authors: Madrigal Brijonnay , Crance Jessica , Berchok Catherine , Stimpert Alison
Published: November 2021

Killer whales occur in the Arctic but few data exist regarding the ecotypes present. Calling behavior differs among ecotypes, which can be distinguished based on pulsed call type, call rate, and bandwidth. Data included in this study were from a passive acoustic recorder deployed 75 km off Point Hope, Alaska, in the southeastern Chukchi Sea (sampling rate 16 kHz, ∼30% duty cycle). A total of 1323 killer whale pulsed calls were detected on 38 of 276 days during the summers (June–August) of 2013–2015. Most calls (n = 804, 61%) were recorded in 2013 with the majority recorded in July (76% of total calls). Calls were manually grouped into six categories: multipart, downsweep, upsweep, modulated, single modulation, and flat. Most detections were flat (n = 485, 37%) or multipart calls (n = 479, 36%), which contained both high and low frequency components. Comparisons with calls reported in the published literature showed similarities with other transient populations in both fundamental frequency contour point distribution and median frequency. This study provides the first comprehensive catalog of transient killer whale calls in this region and reports on previously undescribed calls, providing new insight into transient acoustic behavior and call diversity in the Chukchi Sea.
Acoustic localization of resident killer whales for source-level estimation of echolocation clicks
Authors: Lawson Jack , Wladichuk Jennifer , Dosso Stan , Koblitz Jens
Published: November 2021

To study the efficacy of resident killer whale echolocation clicks for foraging and other activities requires knowledge of the acoustic characteristics of their clicks, in particular, source levels. To compute apparent source level (ASL) from recordings of killer whales in the wild requires localization of the clicking animals, ideally including rigorous uncertainty estimates, to account for transmission losses from source to receiver. This paper considers acoustic localization of killer whales based on time-of-arrival-differences for clicks recorded at a 2 × 2 m2 array of 23 hydrophones. To quantify uncertainties, a Bayesian localization approach is formulated and two methods of solution are considered, one based on a linearized approximation and the other a nonlinear three-dimensional (3D) grid search. Simulations indicate significant linearization errors in 3D uncertainty (probability) distributions, confirming the superiority of the nonlinear localization. Results of this localization approach are used to calculate ASLs (with uncertainties) for echolocation clicks from Southern and Northern Resident killer whales determined to be directed approximately at the array (i.e., on-axis). Comparison of ASL values across varying ranges indicates a roughly logarithmic range dependence, consistent with whales adjusting their click levels based on distance to the target, approximately accounting for two-way spherical-spreading loss.
Characterizing Southern Resident killer whale calls using a particle filter for frequency contour extraction
Authors: Nguyen Hong Duc Paul , Campbell Dave , Joy Ruth
Published: November 2021

With only 74 Southern Resident killer whales (SRKWs) remaining in the waters of the eastern Pacific, understanding these marine mammals is vital to their conservation. Invasive techniques such as focal follows or tagging whales could introduce stress to SRKWs. Instead, passive acoustic monitoring that uses a network of hydrophones one preferred tracking method, particularly in their critical habitat that overlaps the shipping lanes in the Salish Sea. The acoustic data, if processed in real-time using modern deep learning methods, can be used to detect whales and alert ships of the potential for spatial overlap to reduce risks of collision. In this project, we consider the differences in SRKW whale call types from archived recordings of each of J, K, and L pods recorded on regional hydrophones. The whale calls are extracted as functional observations in the time and frequency space from underwater recordings using a particle filter. Functional data analysis (e.g., functional clustering) are performed to characterize the whale calls and represent the variations in call types. Such statistical insights between pod-level call types should be useful for improving machine learning whale detection algorithms, and for identifying SRKW movement in a high ship traffic region of their critical habitat.
Shear wave elastography for muscle biomechanics
Authors: Gennisson Jean-Luc
Published: November 2021

In vivo muscle biomechanical properties are classically deduced from inverse dynamics or measures of joint torque performed using ergometers. However, this provide information about the combined behavior of several structures. Thus, it is complicated to isolate the behavior of an individual muscle. Ultrasound elastography techniques have been developed with the aim to non-invasively assess localized stiffness. In this presentation we focused on the supersonic shear imaging technique that allows to recover stiffness by looking at the propagation of shear waves. In the case of isotropic, homogeneous and quasi-incompressible biological tissues, the propagation velocity is directly linked to the shear elastic modulus. However, this link is not so obvious in muscles due to their anisotropy. Here, we present how stiffness as well as viscosity can be estimated in fusiform muscles but also in pennate muscles by using specific ultrasound sequences that allows to recover directly anisotropy in a 2D imaging plane. Finally, we show how it is possible to estimate nonlinear elastic properties of muscle by deriving the acoustoelasticity theory in a transverse isotropic media. Our hope is to combine all of these mechanical parameters to understand the behavior of a single muscle and deduce its force during movement.
Noninvasive direct assessment of the skeletal muscle function during neuromuscular electrical stimulation
Authors: Kim Kang , Sheng Zhiyu , Sharma Nitin
Published: November 2021

Neuromuscular electrical stimulation (NMES) artificially activates skeletal muscle contraction by sending electrical pulses either to nerves or muscle belly. NMES has been used in various applications in rehabilitation and sports medicine. However, muscle function assessment has been limited to electrical activity measurements by an electromyography, indirect mechanical measurements using a force sensor, or ultrasound imaging that only provides anatomy and structure. In this paper, dynamic contractility of the targeted muscle in response to the NMES stimulation on human subjects is assessed using ultrafast plane wave imaging and speckle tracking. The change of the strain in the targeted muscle due to the continued NMES, resulting in muscle fatigue, was continually measured. By correlating the transient muscle strain with the force measurement as the direct gait function, it has been shown that muscle strain as measure of muscle contractility obtained by ultrasound elastography can be used as surrogate biomarker of muscle fatigue due to NMES. This technology can be used in several applications including NMES integrated exoskeletal for those who lost gait function as feedback to the motion control and NMES dose and monitoring the muscle strength and functional gain by NMES induced muscle treatment and training.
Viscoelastic response ultrasound for interrogating dystrophic muscle degeneration
Authors: Gallippi Caterina M. , Richardson Joseph B. , Moore Christopher J. , Howard James F.
Published: November 2021

Dystrophic muscles undergo repeating cycles of inflammation, necrosis, fibrosis, and fatty deposition, with associated changes in viscoelastic property. Thus, a noninvasive approach to monitoring muscle viscoelasticity is relevant to monitoring disease progression and responses to therapy. Viscoelastic Response (VisR) ultrasound is an acoustic radiation force (ARF) imaging method that executes consecutive, colocated ARF excitations and evaluates the induced on-axis tissue displacement to decipher elastic and viscous properties. Further, by rotating an asymmetrically shaped ARF excitation beam to evaluate elasticity and viscosity along and across the axis of symmetry in transversely isotropic materials, such as muscle, VisR interrogates viscoelastic anisotropy. Finally, machine learning models have been developed to enable quantitative VisR assessments of elastic and viscous moduli. VisR has been demonstrated in vivo for monitoring dystrophic muscle degeneration in boys with Duchenne muscular dystrophy (DMD). Relative to age-matched controls, boys with DMD had higher VisR-derived elasticity and viscosity in early disease stages, when inflammation is present, and higher viscosity in late disease stages after cycles of fatty deposition. Boys with DMD also had lower VisR-derived longitudinal than transverse elastic and viscous moduli, while the opposite was true for controls. VisR is a promising approach to monitoring dystrophic muscle degeneration in DMD.
A miniature ultrasound M-Mode imaging system based on time delay spectrometry
Authors: Bashatah Ahmed , Otto Paul , Mukherjee Biswarup , Chitnis Parag V. , Sikdar Siddhartha
Published: November 2021

For wearable ultrasound applications, power and safety are a concern. We have developed an imaging method based on time-delay spectrometry (TDS) that employs a low-voltage, wideband chirp to establish a relationship between reflector depth and frequency by mixing the transmit and receive signals. We will show a low power, 4 channel ultrasound M-Mode system capable of tracking in vivo muscle interfaces in the forearm. The battery powered imaging system consists of power regulation subsystem, a RF chirp subsystem, and four channels consisting of a transmit RF amplifier, a mixing unit, and a receive amplifier which are sampled at 40 KSPS by a processor with a four channel ADC. The processor performs an FFT on each demodulated return to get 4 scanlines that are tracked over time to produce M-Mode images that are sent to a host computer. The wearable system can provide M-Modes images of up to 4 cm in forearm at a framerate of 50 Hz for ∼7 h with a total power consumption of 1.92 W. We demonstrate the ability of a miniaturized TDS ultrasound imaging system to collect in-vivo M-Modes that can be used for long term monitoring. The system can be used for wearable applications due to its low power consumption. [United States Department of Defense, Congressionally Directed Medical Research Program, award number W81XWH-16-1-0722 (PI: S Sikdar). National Institute of Biomedical Imaging and Bioengineering of the National Institutes of Health under Award No. U01EB027601.]
One problem, two solution approaches: Using the impedance translation theorem and equivalent circuits for graduate level homework
Authors: Anderson Brian E. , Sommerfeldt Scott D.
Published: November 2021

Research applications such as the study of musical instruments, human vocal tract effects on speech, automotive exhaust pipes, HVAC ducts, and others often utilize one-dimensional models of the acoustic systems to determine the resonance behavior and sound radiation properties. The impedance translation theorem and the equivalent circuits method both include all the physics associated with these one-dimensional systems, although one approach or the other may be more appropriate or straightforward to use depending on the result desired. Both these methods are taught at Brigham Young University in two graduate level courses. One of the most challenging and memorable homework assignments from each of these courses is based on using these techniques to analyze a particular acoustic system and compare its response with the real thing. This paper will overview these two techniques and outline how they are applied in homework assignments for these two courses to analyze phonemes produced by altering the human vocal tract.
Soundwalk overview and its application to design
Authors: Brooks Bennett M. , Woolworth David s.
Published: November 2021

How an acoustical environment is perceived by the occupants is a key element in the analysis and successful design of that environment. The goal of such a design effort would be to improve the perception of the acoustical environment and so to enhance the quality of life for the residents, workers and visitors in a locale. The soundscape technique is a powerful method for determining how an environment is perceived under existing conditions, and for developing positive design and planning outcomes. An important and useful tool in the soundscape toolbox is the soundwalk. The protocols for setting up a soundwalk investigation, and the detailed practices which may be followed are described, with reference to the perception data collection procedures as outlined in the ISO 12913 Standard series. Examples of soundwalk data collection are presented. The application of the soundwalk method in the design process is encouraged through case studies presented in this session. Attendees are invited to participate in a live soundwalk conducted at the conclusion of the session.
David T. Blackstock—An international perspective
Authors: Vorlaender Michael
Published: November 2021

The international acoustics community looks back with deep appreciation on the great lifetime achievement of David T. Blackstock. Always interested in international scientific exchange, he was especially involved in the International Commission for Acoustics (ICA) since the 1980s. Without his contributions to understanding across the Iron Curtain, we would not have such harmonious cooperation in acoustics today. This applies not only to the open and trusting cooperation at international conferences, but also to the establishment of firmly rooted support for individual researchers and students who have to work under difficult conditions. This paper looks at David Blackstock's involvement in the ICA, and describes the structures of international collaboration that he was instrumental in initiating.
How graduate work with David T. Blackstock led to a lifelong obsession with wave equations
Authors: Szabo Thomas L.
Published: November 2021

As one of David T. Blackstock’s first graduate students at the University of Rochester (1966), I quickly admired his elegant style of normalizing and solving equations and was baffled by his frequent allusions to great acousticians and mathematicians of the past. Shortly after my arrival, he submitted his transient solution to the viscous wave equation to J.A.S.A. We planned a summer research project (1967) to validate his solution experimentally. He also introduced me to advanced methods for solving equations. David told me there was no general transient solution to this equation, which inspired my determination to solve it. My data confirmed his predictions leading to my first published paper. I left Rochester with an M.S. and afterwards, I filled several notebooks with unsuccessful equations. Eventually, after ten years in ultrasound imaging, I chose the University of Bath for its excellent PhD program in nonlinear acoustics. David visited me there in 1990 and we discussed his 1985 general solution to the Burgers equation. Later at Bath, twenty-three years after beginning, aha moments led me to more general and causal solutions to both linear and nonlinear viscous wave equations for frequency power law media and papers, cited a thousand times.
Improved accuracy and computational efficiency in virtual acoustic rendering using principal components-based amplitude panning
Authors: Neal Matthew , Zahorik Pavel
Published: November 2021

Virtual loudspeaker arrays can be rendered over headphones using a head-related impulse response (HRIR) dataset, but these techniques often introduce undesirable spatial and timbral artifacts that are associated with distortions in the interaural level difference (ILD) cue. Here, a new and efficient virtual acoustic rendering technique that minimizes ILD distortions is described and evaluated. The technique uses principal components analysis (PCA) performed on the time-domain minimum-phase representation of the directionally dependent HRIRs. The resulting principal components (PCs) act as virtual acoustic filters, and the PCA scores are implemented as panning gains. These panning gains map the PC filters to source locations, similar to vector-base amplitude panning (VBAP). Thus, the technique is termed principal components-based amplitude panning (PCBAP). A spatial and spectral error analysis of ILD shows similar reconstruction accuracy is obtained using PCBAP with 15 filters compared to a 256-loudspeaker VBAP array. PCBAP is also scalable to simulate large loudspeaker arrays with a fixed set of PC filters and only small increases in computational requirements. Results from psychophysical testing suggest that perceptual equivalence between a PCBAP-rendered source and a reference source rendered with the original HRIR dataset is directionally dependent but can be achieved with as few as 10–20 PCs.
Web-based remote testing as a viable option for measuring binaural hearing abilities
Authors: Peng Ellen , Burg Emily , Thakkar Tanvi , Godar Shelly , Jang Won , Litovsky Ruth Y.
Published: November 2021

Web-based remote testing can increase access to clinically diverse populations in hearing research. However, whether remote testing affects data quality compared to in-lab testing is unknown. Data for binaural hearing tasks may be particularly vulnerable to commercial-grade hardware limitations and background noise from the testing environment. We replicated two published studies on binaural hearing abilities using a web-based behavioral experimental platform (Gorilla.sc). In Experiment 1, we replicated an experiment by Goupell et al. [JASA 133(4) (2013)] that tested intra-cranial lateralization to interaural time and level difference cues. In Experiment 2, we replicated an experiment by Goupell et al. [JASA 140(3) (2016)] that investigated binaural and contralateral unmasking of speech. Two groups of college-aged young adults were tested: one with verified normal hearing (NH) and one with self-reported NH. Testing took place in participants’ homes using their own computer and audio hardware. Performance was compared between the two groups of participants as well as with published data collected in-lab. For both experiments, performance was similar for in-lab and web-based remote testing. We found no effect of verified versus self-reported NH. These results suggest that remote testing may be a feasible option for binaural hearing experiments. [Work funded by NIH-NIDCD.]
A within-subject comparison of remote and in-laboratory methods for auditory detection studies
Authors: Ugolini Margaret H. , Thompson Eric R. , Mobley Frank S.
Published: November 2021

While the gold standard of psychoacoustic research involves tightly controlled, laboratory-based inquiry, it has been necessary to develop protocols to conduct experiments on auditory perception outside of the lab without sacrificing experimental rigor and data quality. Outside of the lab, there is the potential for differences in acoustic environment across subjects, as well as increased auditory and visual distractions. The present study compares the difference in performance on a masked auditory detection experiment within the same cohort of subjects across two platforms of varying experimental control: (1) an in-lab, computer-based experiment conducted within a sound booth; and (2) a remote, tablet-based experiment conducted with provided noise-isolating headphones in an uncontrolled—but measured—acoustic environment. Comparisons in performance across experimental platforms and settings will be discussed, including the influence of a concurrent visual task to encourage task focus, and the effect of background noise levels on performance in the remote setting. Results suggest that there was little influence of the setting and equipment on subjects’ performance in this masked auditory detection study, as similar results were obtained in both settings. This work aims to provide guidance on best-practices for conducting remote acoustic studies without a detriment to data quality.
The relationship between spatial release from masking and the ventriloquist effect
Authors: Holmes Ann , Neal Matthew , Zahorik Pavel
Published: November 2021

Speech is often multisensory and the perception of auditory-visual cues may not always match reality. This experiment explored how spatial release from masking (SRM) can be influenced by perceptual shifts in spatial location through the ventriloquist effect, and whether such shifts impact speech perception. Normal hearing participants completed two tasks: a localization task and an intelligibility task. Both tasks employed audio-video recordings of the Coordinate Response Measure [Kishline et al., J. Acoust. Soc. Am. 148, 492–495 (2020)] and participants were asked to indicate the location of a talker or to report keywords spoken by one talker in the presence of a competing talker. Participants were exposed to auditory-only and auditory-visual conditions of each task, and in the auditory-visual conditions, audio location was either matched or mismatched with the video location. Listeners showed strong SRM on keyword identification in auditory only conditions and strong visual capture of the auditory target to the talker irrespective of true auditory location. Despite this combination of results predicting a strong perceived SRM elicited by ventriloquism, only moderate perceived SRM was observed from mismatched auditory-visual conditions. Further discussion will address the relative contribution of visuals in matched conditions and effects of perceptual SRM.
Quantitative characterization of microstructure in additively manufactured metals with nonlinear ultrasound
Authors: Bellotti Aurelio , Kim Jin Yeon , Bishop Joseph , Jared Bradley , Johnson Kyle , Susan Donald , Noell Philip , Donahue Carly , Jacobs Laurence
Published: November 2021

Our work employs nonlinear ultrasonic techniques to track microstructural changes in additively manufactured metals. One study is based on the use of the second harmonic generation technique with Rayleigh surface waves used to measure the acoustic nonlinearity parameter, β. Stainless steel specimens made through laser-powder bed fusion and laser engineered net shaping were compared with traditional wrought manufactured specimens. The β parameter is measured through successive steps of an annealing heat treatment intended to decrease dislocation density. In agreement with fundamental material models for the dislocation-acoustic nonlinearity relationship in the second harmonic generation, β drops for each specimen throughout the heat treatment before recrystallization. Geometrically necessary dislocations (GNDs) are measured from electron back-scatter diffraction as a quantitative indicator of dislocations; average GND density and β are found to have a statistical correlation coefficient of 0.852 showing the sensitivity of β to dislocations in additively manufactured metals. Moreover, β shows an excellent correlation with hardness, which is a measure of the macroscopic effect of dislocations. Ongoing work continues trying to characterize additively manufactured stainless steels with nonlinear ultrasound through non-collinear mixing.
Ultrasonics for monitoring melt pool dynamics and in situ sensing of microstructure during powder bed fusion additive manufacturing
Authors: Kube Christopher M. , Kizer Nathan , Nassar Abdalla , Reutzel Edward , Zhang Haifeng , Rollett Anthony , Sun Tao
Published: November 2021

Ultrasonics are viable tools to monitor internal microstructure of polycrystalline metals. Recently, the need for such tools has dramatically increased as metallic additively manufactured (AM) materials are rapidly becoming common in engineered structures. Nondestructive techniques like X-ray CT and ultrasonics are increasingly being used as a quality control step to help assure performance. Ultrasonics can also be used to help improve and develop AM processes by integration as an in situ method to assess the relationship between part microstructure and process parameters. This presentation will cover the development of two in situ ultrasonic techniques aimed at improving the state of the art in metal AM. First, ultrasound is employed to monitor keyhole melt pool dynamics in Al6061 samples. In this application, a high-frequency ultrasonic shear wave scatters from the liquid-solid boundary of the melt pool, which allows us to monitor keyhole initiation, melt pool depth, fluctuations in depth, and solidification. The sensitivity was confirmed through ground truth measurements using simultaneous synchrotron x-ray imaging. Then, progress on using in situ diffuse ultrasonic scattering on Gr91 powder bed fusion parts will be highlighted. The microstructure sensitivity of diffuse scattering is thought to be able to discern the formation of different microstructures during the manufacturing process.
Binder jet printing barium titanate piezoelectric ceramic discs
Authors: Schipf David , Yesner Gregory , Guild Matthew D.
Published: November 2021

In this study, we measure the properties of barium titanate (BaTiO3) piezoceramic discs that have been binder jet printed and infiltrated with epoxy. Binder jet printing is a scalable and relatively inexpensive additive manufacturing technique. With binder jet printing, it is possible to produce atypical geometries, and large quantities of transducers on demand without expensive tooling. However, there are many practical challenges with binder jet printing ceramics, and sintered parts tend to have relatively low densities. We seek to address these challenges and explore the suitability of binder jet printing piezoelectric transducers and active materials. In this presentation we will discuss our techniques for printing and post-processing BaTiO3 ceramic discs. We will discuss porosity, and how epoxy infiltration can improve the functionality of discs. We will present measurements of discs fabricated using a traditional pressing method and measurements of printed discs. These measurements include density, dielectric permittivity, piezoelectric coefficient d33, impedance and dielectric loss. From our measurements, we will attempt to model relationships between printing parameters and final properties. Printing and powder processing techniques that can increase relative density of sintered parts will also be discussed. [Work sponsored by the Office of Naval Research Distribution A: Approved for public release.]
Investigation of possible Near-merger in Mandarin nasal codas
Authors: Liu Suyuan
Published: November 2021

The two codas /n/ and /ŋ/ in Mandarin are known to undergo merger in production of speakers from various dialect groups such as Shanghai Mandarin (Faytak et al., 2020) and Taiwan Mandarin (Chiu et al., 2019). A study by Faytak et al. (2020) revealed that even for Beijing Mandarin speakers, who do not show such a merger in production, they still could not distinguish /n/ and /ŋ/ in perception. This indicates a possible instance of near merger in Standard Mandarin, meaning speakers can distinguish between two sounds in production but not in perception (Labov et al., 1991). This study aims to validate whether Mandarin nasal codas demonstrate patterns of near merger with consideration of potential influence by dialect groups. Both speakers of Beijing Mandarin and speakers of Shanghai Mandarin will be recruited. This study consists of one production section where subjects produce minimal pairs in Mandarin that only differ in coda position, and a perception task involving a phoneme categorization task and a goodness rating task of various productions of /n/ and /ŋ/. The hypothesis is that listeners’ perceptual performance will correlate with their production pattern (e.g., Fridland and Kendall, 2012). However, if this study validates near merger in Mandarin coda nasals, this will be the first case of a non-tonal near merger in Mandarin. If otherwise, this study still sheds light on how speakers from various Chinese dialect groups might exhibit different cue-weighting strategies.
The prioritization of consonants, vowels, and tone in Cantonese word recognition
Authors: Fung Fion , Soo Rachel , Babel Molly
Published: November 2021

Sound contrasts are redundantly cued in the speech stream by acoustic features spanning various time scales. Listeners are presented with evidence for a particular category at various temporal intervals, and must coalesce this information into a coherent percept to accurately achieve recognition. Previous work on tone languages has shown that listeners prioritize consonants, then vowels, then lexical tone during phonological and word processing, despite lexical tone being a suprasegmental cue that unfolds with the vowel. We present an online eye-tracking study to assess the time course of Cantonese listeners' recognition of a target word (e.g., 包 /pa⌢u55/ `bun') with competitors for rime (北 /pak55/ `north'), onset (敲 /ha⌢u55/ `to knock'), and tone (爆 /pa⌢uu33/ `to explode') co-present on the screen. This design allows a test of the role of relative prioritization and contribution of consonant, vowel, and tone information in phonological processing. If vowels are prioritized before tones, we predict increased looking times to tone competitors. If vowels and tones are processed jointly, we predict equal looking times to both vowel and tone competitors. Data collection with Gorilla is ongoing. Data analysis will focus on overall proportions of looking-time to the target and competitors.
Manipulating listener attitudes toward accented talkers influences speech perception
Authors: Cammarata Philbrick Melanie , Ingvalson Erin
Published: November 2021

We previously demonstrated that listeners' attitudes toward talkers with foreign accents is related to listeners' ability to perceive foreign-accented speech. In this study, we sought to determine if listeners' attitudes toward talkers with foreign accents are malleable and, if so, whether changing listeners' attitudes toward talkers with foreign accents would change the strength of the relationship between listeners' attitudes and listeners' speech perception accuracy. Specifically, we hypothesized that supporting listeners’ biases regarding non-native speech would lead to better speech perception performance. To test this hypothesis, we created short vignettes that either conformed to or violated listeners’ biases regarding non-native talkers. Native English-speaking listeners rated and transcribed speech produced by native and non-native English speakers. Half of the listeners read the vignette prior to rating the speech, half received no information about the talkers; vignettes were randomly paired with talkers. Contrary to our hypothesis, there was no effect of vignette type. Listeners rated non-native listeners as more accented and less likeable when vignettes were present. Interestingly, listeners were also more accurate transcribing speech by both native and non-native talkers when the vignettes were present.
The effect of seabed roughness on passive fathometer measurements
Authors: Olson Derek
Published: November 2021

The seafloor is rough on a variety of horizontal scales spanning several orders of magnitude. This roughness, together with subbottom roughness and volume heterogeneities can play a role in scattering ambient sound. When the ambient sound pressure field is used to remotely sense the seafloor using passive fathometer techniques, scattering may cause a departure from the plane wave models that are commonly fit to passive estimates of the bottom reflection coefficient. Here, a model for the effect of scattering on passive reflection measurements is developed for an isovelocity water column. Results are shown for a rough half-space, and a rough layered seafloor. The bias introduced into geoacoustic inversions by the presence of seafloor scattering is investigated. [This work was supported by the U.S. Office of Naval Research.]
Probabilistic focalization for shallow water localization
Authors: Meyer Florian , Gemba Kay L.
Published: November 2021

We consider passive localization and tracking of an underwater acoustic source from measurements provided by a vertical line array. A focalization approach is introduced that probabilistically associates detected directions of arrival (DOAs) to modeled DOAs and jointly estimates the time-varying source location. Modelled DOAs are provided by an embedded ray tracing processor that makes use of environmental parameters to characterize the acoustic waveguide. Due to its statistical model, the proposed Bayesian method can provide robustness against inaccurate environmental parameters as well as an uncertainty characterization for estimated source locations. We demonstrate performance advantages compared to matched field processing using data collected during the SWellEx-96 experiment.
Computational Bayesian inference of range and depth of a mobile scatterer in a refractive ocean waveguide with a limited vertical aperture array
Authors: Barros Abner C. , Gendron Paul J.
Published: November 2021

A computational Bayesian method is presented for inference from a limited vertical aperture regarding the range, depth and speed of a submerged large mobile object. Closely spaced multipath arrivals in Doppler and vertical angle off of the target in a refractive environment are addressed in the presence of uncertainty in the ambient acoustic noise power. Vertical angles and Doppler frequencies of the arrival structure are jointly inferred and their posterior density is mapped to the object’s range, depth, and speed through acoustic ray interpolation. A case study with the classic Munk sound speed profile is presented to lend credence to the approach.
Numerical modeling of the sound field interference pattern in the presence of intense internal waves
Authors: Pereselkov Sergey A. , Kuz'kin Venedikt , Kaznacheeva Elena
Published: November 2021

The purpose of the paper is numerical modeling of the sound field in the presence of intense internal waves to study the interference pattern in inhomogeneous ocean waveguide. It is assumed that intense internal waves are the reason for the sound field modes coupling and horizontal refraction. The results of sound field modeling are processed to obtain acoustic intensity distributions in the frequency-time domain (interferogram) for unmoving sources. The two-dimensional Fourier transform (2D-FT) is applied to analyze the interferogram. The result of the 2D-FT can be called the Fourier-hologram (hologram). The hologram allows us to coherently accumulate the sound intensity of the interferogram in the narrow area as focal spots. It is demonstrated in the paper that the position of focal spots in the hologram depends on the distance between the source and the receiver. The relationship between the interferogram and hologram structures and the unperturbed and scattered fields parameters is obtained in the paper. The hologram spectral density consists of the two disjoint regions corresponding to the scattered and scattered fields. The filtering of these areas allows us to transmit the non-distorted information through an inhomogeneous ocean environment. The numerical simulation results of interferograms and holograms in the presence of the internal waves are considered. [This research was supported by the RFBR (19-29-06075, 19-38-90326).]
Abnormal interference of very low frequency sound field in shallow water
Authors: Piao Shengchun , Dong Yang , Wu Zhiqiang
Published: November 2021

In a multi-channel seismic exploration experiment in the South Yellow Sea, a tuned air gun array with a shooting interval of 37.5m was used as broadband pulse source, and a horizontal line array with 336 elements is used to receive transmitted signals. The received single shot records in the range-time domain are transformed into an interference pattern in the range-frequency domain using Fourier transform. It is found that there is an abnormal interference pattern of the very low frequency (VLF) sound field in the stratified shallow water environment. It is a complex nonlinear structure, no longer regular striations in the range-frequency domain. The mechanism of this particular interference pattern is interpreted according to normal mode theory. In shallow water stratified leaky waveguide, VLF sound propagates as waterborne modes and bottom-trapped modes. These two kinds of normal mode interfere with each other and form the particular stable interference pattern. In the experimental environment, the group speeds for these two type normal modes change differently with frequency. And it causes slope of interference striations change from positive to negative with increase of frequency. The theoretical simulation results are in good agreement with the experimental data. It is shown that the structure of interference pattern is sensitive to bottom structure and geoacoustic parameters.
Acoustic modeling in the Beaufort Sea using measurements and models of ocean sound speed
Authors: Desrochers Jessica , Van Uffelen Lora , Webster Sarah E. , Dzieciuch Matthew A. , Worcester Peter F.
Published: November 2021

Environmental changes in the Arctic over the last few decades have resulted in a subsurface sound speed duct located between 100- and 300-meters depth, known as the Beaufort Duct, which allows for long range acoustic propagation with little or no interference from the ocean surface or bottom. In 2017, two Seagliders traversed between five moored active acoustic sources transmitting linear frequency modulated (LFM) sweeps with frequencies around 250 Hz. During the experiment the Seagliders recorded acoustic arrivals and measured temperature, salinity, and pressure. These environmental measurements are used to calculate sound speed for use as an input to forward acoustic propagation models, including rays and broadband parabolic equation predictions of acoustic time fronts. Results are compared with acoustic propagation predictions based on sound-speed profiles from ocean models as well as measured acoustic data. The measured and modeled acoustic arrival times along with the calculated sound-speed profiles of the region are used to explore the inverse problem.
Celebrating sound in Physics Today
Authors: Middleton Christine
Published: November 2021

To recognize the International Year of Sound, Physics Today devoted the feature articles section of its December 2020 issue to highlighting areas of acoustics research. My talk will cover how the special issue came together as well as the magazine's coverage of acoustics in general.
Making waves in Elkhart for the international year of sound
Authors: Brockman Jay B.
Published: November 2021

Making waves is a unique partnership between K–12 and college educators, Grammy-winning musicians, and a small woodworking business that offers educational programs that blur the lines between the STEM fields and music to bring out the best in students’ abilities to experiment, create, analyze, and explore. Using topics drawn from grade-level standards in engineering, math, and science, as well as best practices in music education, students build and analyze custom musical instruments from kits and then compose and perform original works using those instruments. During the 2020–2021 school year, with COVID-19 restrictions in place, Making Waves moved its afterschool program with Elkhart, Indiana elementary and middle school students into a hybrid online learning mode, with instructors from across the country working remotely with Elkhart students in their classrooms. In celebration of the International Year of Sound, the team produced an arrangement of “The Sound of the World,” with a video highlighting student learning and the musical heritage of the Elkhart community. This presentation will feature this video, along with audience participation activities.
The Detroit Orchestra Hall “Centennial Sound Lab” multi-location binaural acoustic measurement and audition project
Authors: Bray Wade R.
Published: November 2021

Detroit Orchestra Hall, opened in October 1919, entered its centennial year in October 2019 with a variety of special events. A Board member, a recently retired automotive sound quality engineer, suggested starting the celebration with a comparative audition study of the Detroit Symphony Orchestra in Orchestra Hall with acquisition and analyses “using the tools of Sound Quality engineering.” HEAD acoustics, Inc., was contacted by Symphony management and data were acquired during a dress rehearsal of the Brahms Fourth Symphony using five Aachen HEAD Measurement Systems (HMS): four at various seats in the Hall and one onstage behind the brass section. Analysis included conventional, psychoacoustic and advanced psychoacoustic tools including the Hearing Model of Sottek. One revealing analysis was an animatable display of left and right ear levels and loudnesses as XY plots, the left ear plotted on the vertical axis and right on the horizontal. In collaboration with Jaffe Holden Acoustics, Orchestra Hall acousticians, two presentations were made: one to the public as part of a roundtable discussion in the Hall, the other to Board members and donors including calibrated binaural playback in the Hall with ability to “jump” seamlessly during playback from any recorded seat to any other.
The perception of ultrasonic signals in quiet and noise by mice exposed to noise
Authors: Charlton Payton , Burke Kali , Kobrina Anastasiya , Lauer Amanda M. , Dent Micheal
Published: November 2021

High-intensity noise exposures can lead to temporary or permanent increases in hearing thresholds for simple and complex stimuli. Mice produce complex signals known as ultrasonic vocalizations in a variety of behavioral contexts and it is thought these vocalizations serve a communicative function. The effects of a 2-h exposure to 8–16 kHz narrowband noise at 100 dB SPL on auditory sensitivity thresholds for two types of ultrasonic vocalizations (complex and downsweep vocalizations) in two different listening conditions (quiet and continuous 60 dB white noise) were measured. Male and female mice ranging from 100 to 1000 days old were trained to detect the vocalizations in a go/no-go operant conditioning paradigm with positive reinforcement. Each mouse participated in only one condition. Once consistent thresholds were obtained for a mouse, they were subjected to the noise exposure. Post-noise thresholds were obtained on a daily basis for up to 120 days. Similar to humans exposed to a traumatic noise, there was a lot of variability in the extent of the hearing loss following the noise exposures, with some mice experiencing large threshold shifts and other mice exhibiting only minor, temporary hearing loss. [Work supported by NIH DC016641.]
Autonomy, soft-robotics, deep learning, and bat biosonar
Authors: Müller Rolf , Chakrabarti Sounak , Eshera Ibrahim M. , Lagad Sanmeel Vijay , Wang Ruihao , Zhang Liujun
Published: November 2021

Echolocating bat species that inhabit dense vegetation are promising model systems for achieving autonomy in complex natural environments. To replicate the skills of the bats in extracting information about complex environment that can support autonomous navigation in a man-made system three aspects deserve particular attention: (i) encoding of relevant sensory information; (ii) information extraction; and (iii) integration of information encoding and extraction with each other and the respective context. To facilitate progress towards understanding these issues, a biomimetic sonar system is being developed that is aimed at recreating the flexibility and variability that bats exhibit in the configuration of the emission and reception baffles of their biosonar systems (i.e., noseleaves and pinnae). Analyzing the significance of these dynamic effects on sensory information encoding requires an understanding of the stimulus ensemble of biosonar tasks in natural environment. To this end, the biomimetic sonar system has been used to collect large data sets with echoes that pertain to fundamental navigation tasks such as localization and passageway finding. Deep-learning methods have been shown to be a good match for analyzing this echo data. Finally, ongoing research is directed at data acquisition and inference with the specifics of a given habitat and biosonar task.