bluuebunny/crossref_metadata_2025 huggingface dataset:
A new approach for auralization of scattering in urban spaces
Authors: Heimes Anne , Vorlaender Michael
Published: April 2023

Absorption and scattering coefficients of surfaces are crucial for acoustic propagation simulations. The scattering coefficient according to ISO 17497-1, however, is the most uncertain standard metric applied in geometrical acoustics. In outdoor sound propagation simulation, the amount of scattered energy is crucial for the sound immission at the receiver. Standard random-incidence scattering coefficients are in use but with uncertain results. In contrast, specific reflection patterns are neither available nor implemented in simulation algorithms. In this paper, the scattering coefficient concept will be applied for building facades in an urban test environment. Furthermore, results from a new angle-dependent specific scattering metric, including sound steering and retro-reflection, will be compared with results from purely specular or mixed specular/random-incidence datasets.
Passive acoustic localization and tracking of Rice’s whales (Balaenoptera ricei) in the northeastern Gulf of Mexico
Authors: Tenorio Ludovic , Gruden Pina , Frouin-Mouy Heloise , Debich Amanda , Cook Ashley , Garrison Lance , Nosal Eva-Marie , Soldevilla Melissa
Published: April 2023

The endangered Rice’s whale (Balaenoptera ricei) is endemic to the Gulf of Mexico and is also the Gulf’s only resident baleen whale. Limited knowledge of this species’ ecology combined with the high industrialization of this region raises serious conservation concerns. As part of an ongoing project to study the Rice’s whale in its core habitat, an array of moored passive acoustic monitoring sites has been near-continuously deployed in the northeastern Gulf of Mexico since May 2021. While detecting Rice’s whale calls in these data provides valuable insight into the species’ spatiotemporal distribution, further analyses to localize and track individual whales would allow better characterization of their acoustic behavior and movement patterns, possibly allowing for density estimation. Here, we present a method for automated passive acoustic localization and tracking of calling Rice’s whales. The two key components of this approach are (1) the use of opportunistic sound sources to time-synchronize recordings across sites given clock-drift between acoustic recorders and (2) the implementation of automatic multi-target tracking techniques based on the Gaussian mixture probability hypothesis density filter. Analyses of the first four months of data show potential for measuring basic behavioral parameters such as calling rate, source level, and average swim speed.
A generic AI pipeline for identifying known species and discovering new species
Authors: Campos-Cerqueira Marconi
Published: April 2023

To counterattack the current biodiversity crisis, we need innovative tools and technologies that can greatly improve species identification and discovery at scale. Here, we describe a data analysis pipeline to automatically identify biological sound categories in soundscape data and accelerate the discovery of new species. The pipeline consists of two components: (1) Unsupervised audio event detection and clustering that enables automatic detection and categorization of biological sounds in large audio datasets and (2) supervised deep learning-based signal detection that enables automated cluster labeling and detection of known sound categories in new audio. We evaluated the results of our unsupervised analysis tools applied to a labeled dataset of ∼18 h of recordings from Panama. Experts assigned a label to each sound event with a max frequency of 6 kHz. Our results show that clusters generally had high homogeneity and completeness and indicate that our cluster analysis tool can successfully detect and group like-sounds together, improving data processing and species identification. In addition, we were able to implement these analytical tools in a user-friendly data analysis platform that will provide scientists, wildlife managers, conservationists, and public and private environmental organizations with the information they need to make informed conservation and management decisions.
Potential biological impacts of very low frequency acoustical energy produced by offshore wind turbine energy generation
Authors: Stocker Michael
Published: April 2023

Offshore wind turbine farms are being planned and installed around the US Outer Continental Shelf. These will be introducing a panoply of noises into the environment, from siting, through installation, to operations, and eventually decommissioning. Noise concerns from these activities are typically framed within frequency bands of concern defined by governmental regulatory agencies. A less considered noise is the very low frequency thump generated by the motion of the turbine blades as they intersect the “stagnate wind area” on the windward side of the mast. This “infrasonic” thump contains a lot of energy and is in the perceptual range of migratory birds and baleen whales. Given that whales and birds use “infrasonic” sound and barometric pressure signals for navigation and migration cues, the installation of thousands of turbines off the Atlantic Outer Continental Shelf, and hundreds off the Pacific OCS, may impose significant impacts on migratory passerine birds along the “Atlantic Flyway,” Procellariiformes on both the Atlantic and Pacific OCS, and all baleen whales within the infrasonic energy propagation reach of the turbines.
Beneath the tree: The sounds of a trembling giant
Authors: Rice Jeff , Oditt Lance
Published: April 2023

The Pando aspen grove (Populus tremuloides) consists of more than 40000 genetically identical aspen stems spread across 106 acres in south-central Utah. While Pando resembles a forest, it is a single organism connected at the roots, making it the world's largest tree and one of the largest living things on the planet. First identified in 1976, Pando has not been studied as a bioacoustic subject. Focusing on recordings captured simultaneously above and below ground on July 12, 2022 during a thunderstorm, our presentation reveals a unique acoustic portrait of this botanical wonder. We compare audible sounds of Pando’s leaves with hydrophone recordings made in connection with the tree's root system. This dual soundscape shows that leaf motion causes vibrations that pass throughout the organism, from its branches to its base. The recordings suggest that the grove’s massive, interconnected root system is highly resonant with potential for future recordings and research.
Adaptive signal adjustments in humpback whale songs
Authors: Wagome Vitalis , Mercado Eduardo
Published: April 2023

The use of vocal flexibility by humpback whales (Megaptera noavaengliae) often described as “singing” is a highly sophisticated communicative process, possessing a multilayered hierarchical structure across the various acoustical parameters. A deeper spectral analysis of songs made available through Google's Pattern Radio website studied in the month of February 2015 display several adaptive signal adjustments in humpback whale songs. As single singer variations in song properties become more clear, multi-singer variations in song properties remain hypothetical. This raises an important question of incorporating a temporal analysis approach to determine the multi-singer variations in song properties.
Correlation between lung maturity and backscatter coefficient calculations in fetal lung. Simulations
Authors: Esquivel-Sirvent Raul , Quiterio Irene , Amaya-Guel Yubia , Torres-Robles Fabian
Published: April 2023

Fetal lung maturity is a public health problem, and developing quantitative ultrasonic (QUS) techniques has become a possible way of assessing lung development. To estimate the feasibility of using quantitative medical ultrasound, we performed numerical simulations of radio frequency signals scattered from lung tissue. Given the distribution of sizes of alveoli, and wall lining thicknesses corresponding to different stages of lung maturity, we calculate the effective speed of sound using an effective medium approximation. The attenuation and backscattering coefficient is calculated from many-body scattering techniques. Also, for the attenuation and the backscattering coefficient, different statistical configurations are considered to determine the correlation between size of alveoli and acoustic properties. The results using QUS are compared to light scattering techniques (1). Our simulations are compared with ultrasonic measurements made with sponges with different pore sizes following the work of . Once the measurements are analyzed, the sponges are cut and analyzed under a dark-filed microscope to obtain the average size of pores. As a proof of concept, we show that quantitative medical ultrasound can provide information on fetal lung maturity accurately. (1) M. S. Durkee, G. K. Fletcher, C. Carlson, K. Matheson, S. K. Swift, et al. Opt. Lett. Vol. 43, No. 20, 5001 (2018).
Random matrix theory (RMT) to quantify scattering behavior in lung mimicking phantoms
Authors: Dong Zihan , Cole Azadeh D. , Onuorah Chukwuka W. , Ware Henry O. , Muller Marie
Published: April 2023

As we previously reported in rodent lungs, RMT parameters (Expected value E(x), and λmax, the eigenvalue with the highest probability) extracted from singular value decomposition (SVD) of inter-element response matrix (IRM) show a significant correlation with fibrosis histology scores. The lack of fibrotic models for larger lungs such as pigs motivated us to investigate porous 3D printed PEGDA phantoms with controllable strut size and alveolar density. We hypothesize that E(x), and λmax can distinguish phantoms with different alveolar size, by evaluating multiple scattering in the backscattered signals. IRMs were acquired using a 128-element linear array L7-4 (Verasonics, at 5.2 MHz central frequency) connected to a Verasonics Vantage ultrasound scanner. Phantoms of 1-inches size with different strut diameters of 0.085, 0.17, and 0.26 mm were used. Attenuation constants for these samples were measured using the Substitution Method at 1 MHz, 2.25MHz, and 5 MHz to evaluate scattering attenuation. E(x), and λmax were evaluated using SVD of the IRM. Attenuation constants, E(x), and λmax all show that the phantoms with larger strut size exhibit more multiple scattering than phantoms with smaller strut size. These preliminary results suggest that such phantoms could be used to mimic pulmonary fibrosis.
Structured mentoring process
Authors: Chen Hong
Published: April 2023

I am fortunate to have great mentors who believe in me and encourage me to reach beyond my self-doubts and make it possible for me to achieve more than I initially thought possible. I am now a professor, and how to be a great mentor has always been a question that I ask myself. Over the past seven years, I have developed a structured mentoring process to guide my practice. This structure has four phases: (1) 1–4 months to decide whether there is a good fit between the mentor and mentee; (2) 4–12 months to build the relationship by working closely with mentees to understand their career goals, passions, strengths, and weakness and working with mentees to formulate mentee development objectives; (3) 1–4 years to maintain the momentum of mentoring and regularly (every semester) check on the progress in mentoring; (4) End formal mentoring when mentees leave the lab but maintaining lifelong support to mentee’s career development. I will share how this structured mentoring process works in my lab and solicit feedback and suggestions on how to improve this process.
A four-prong approach for engaging biomedical engineering students
Authors: Szabo Thomas L.
Published: April 2023

My involvement in a large medical imaging company for nearly 20 years shaped my approach to teaching biomedical engineering. These experiences are described in Medical Physics International Journal, 6,602–620, May 2021. At Boston University, I taught undergraduates using a four pronged approach. The first part included a “lessons learned” career overview lecture and discussion to incoming freshman. This talk emphasized shifting paradigms in medical device development and changing trends in research and development and how to best prepare for a biomedical engineering career by prudent course selection, practical experience and life-long networking. Second, I designed two ultrasound lab modules which were part of the mandatory physiology lab all juniors took. These laboratories provided condensed theory with hands-on experiments on imaging and Doppler processing/imaging and data analysis. Third, I taught ultrasound and medical imaging courses which included rigorous theory, applications and examples. My book, Diagnostic Ultrasound Imaging: Inside Out, second edition, is being used in ultrasound courses throughout the world. A new book and curriculum, coauthored with Peter Kaczkowski, and sponsored by Verasonics, is underway. Finally, for 15 years, I taught a usually two semester course in entrepreneurship, innovation and engineering design which culminated in a team-based senior project.
Computational aeroacoustics in flexible conduits with application to biomedical fluid dynamics
Authors: Laudato Marco , Mihaescu Mihai , Zea Elias , Boij Susann
Published: April 2023

Flexible tubes are simple yet powerful tools for the modeling of respiratory and circulatory systems [1, 2]. In the last decade, access to high-performancecomputational resources has allowed the implementation of realistic numerical models of human vessels based on Computational Fluid Dynamics (CFD) and Fluid-Structure Interaction (FSI) simulations. Interestingly, the recently proven correlation [3] between CFD observables (like the pharyngeal airway's resistance) and clinical data (such as the Apnoea Hypopnea Index in Obstructive Sleep Apnoea patients) suggests a possible development of diagnostic methods based on numerical simulations. This work aims to investigate the extension of these correlations to the aeroacoustics characteristics of flexible conduits by means of a fully coupled FSI numerical model based on the Large Eddy Simulation method. These results have relevant applications to studying diseases of the human upper vocal tract, voice production, obstructive sleep apnoea, and adventitious lung sounds, such as wheezing and crackling. [1] Grotberg, J. B., & Jensen, O. E. (2004). Annu. Rev. Fluid Mech., 36, 121–147. [2] Schwartz, A. R., & Smith, P. L. (2013). The Journal of physiology, 591(Pt 9), 2229. [3] Schickhofer L., Malinen J., Mihaescu M., J. Acoust. Soc. Am. - JASA, 145 (4): 2049–2061, 2019. https://doi.org/10.1121/1.5095250
Numerical calculations with an exact analytical time-domain Green’s function for the van Wijngaarden wave equation
Authors: Holmes Vaughn E. , McGough Robert J.
Published: April 2023

An exact analytical time-domain Green’s function is obtained for the van Wijngaarden wave equation when two of the constant coefficients satisfy a certain equality. This analytical expression enables numerical assessments demonstrating that lossy time-domain Green’s function calculations with the inverse fast Fourier transform (IFFT) produce larger errors than expected for most temporal values, even when the IFFT is evaluated with several million points. This analytical time-domain Green’s function also provides the foundation for efficient numerical calculations of spatial impulse responses, which are demonstrated for a 1 cm radius circular piston radiating in water at axial distances of 1 cm, 10 cm, and 1 m. As the axial distance increases, the difference between the lossy and lossless spatial impulse responses also increases, which is particularly evident in the paraxial region. However, the difference between lossy and lossless spatial impulse responses diminishes as the observation point transitions from an on-axis location to another position with the same axial distance just outside of the paraxial region. The observed differences between the lossy and lossless spatial impulse responses transitioning out of the paraxial region are explained by comparing the relative temporal extents of the lossless spatial impulse response and the lossy time-domain Green’s function.
3D printed acoustic metamaterial filters for the mitigation of inaudible ultrasound attacks on smart speakers
Authors: Lloyd Joshua , Ludwikowski Cole , Phansalkar Derek , Malik Cyrus , Shen Chen
Published: April 2023

Acoustic metamaterials have shown great potential in manipulating acoustic waves with a small footprint and versatile functionality. While their usefulness has been demonstrated in many fields including noise reduction and biomedical ultrasound, not many studies have been done in the field of audible acoustics and speakers. In this work, we show that an acoustic metamaterial-based filter can enhance the security of smart speakers, which are susceptible to inaudible ultrasound attacks due to the shadow effect of the microphones. The filter contains several resonant unit cells which collectively modulate the received signals in the ultrasound spectrum and, thus, mitigate inaudible attacks on smart speakers. On the other hand, normal audible signals are not affected and, therefore, regular functionality is not disturbed. The filtering effect is verified numerically using finite element analysis. Measurements are performed to validate the concept, where it is shown that inaudible ultrasound attacks are effectively blocked when the 3D-printed metamaterial filters are installed. This demonstration shows a possible way to apply acoustic metamaterials in consumer electronics such as smart speakers.
Archtop guitar dynamics—Continuing research of archtop guitar acoustics
Authors: Nania Thomas
Published: April 2023

The contemporary archtop guitar, designed by Lloyd Loar of the Gibson Mandolin-Guitar Mfg. Co. Ltd., will be 100 years old in 2023. Since the first L5 shipped in 1923, the archtop guitar has taken on a life of its own, having been reinvented by luthiers worldwide. Research of the archtop guitar is a new field in instrument acoustics. Measurement techniques developed by the bowed instrument research community have been adapted for guitar to offer a glimpse into the acoustic behavior of a century old, yet timeless guitar design. This talk will focus on the ongoing research that has been conducted since the 2021 publication of Archtop Guitar Dynamics by the Violin Society of America Papers. The archtop guitar shares features of violin family instruments, including a carved top, ff-hole perforations, and raised bridge. Beyond aesthetics, the archtop shares acoustic similarities to both violin and guitar family instruments resulting in a unique acoustic signature. Continuing research includes analysis of historically significant instruments from Gibson Mandolin-Guitar Mfg. Co. Ltd and the works of New York luthier, John D'Angelico as part of the Archtop Project: New York sponsored by D'Addario & Co. and the Archtop Foundation.
Factors that affect guitar timbre
Authors: Ramsey Gordon P. , Moore Jessica R.
Published: April 2023

This is part one of two presentations on the same project. Guitars have been used for centuries, but their versatility due to technical developments have made them very popular in most genres of music. Our research has investigated how various physical properties of the guitar affect its timbre. We have investigated the effects of (a) string excitement location, (b) string type and gauge, (c) pick versus pluck excitement, and (e) the placement of a capo on an acoustic guitar. The main goal is to investigate how each of these factors play a role in certain genres of music where guitars are one of the main instruments. Measurements were taken at the LU acoustics lab and the anechoic chamber at Northwestern. This talk will present theoretical basis for our measurements and discuss the effects of the pick versus pluck and placing a capo on the neck of the guitar. The following talk will discuss the remaining factors and how our study contributes to the capability of the player to create different moods.
How musicians can utilize the guitar’s acoustic properties
Authors: Moore Jessica R. , Ramsey Gordon P.
Published: April 2023

Guitars are extremely versatile instruments due to the myriad of ways in which the player can alter the timbre. Specific adjustments are made to the guitar that correspond to stylistic distinctions between genres of music. This study explores how the timbre of the guitar is affected by the string type, gauge, and excitement location, in addition to the previous talk topics. Using the spectra, we can determine how our results can be utilized by musicians. Continuing from the first talk on the physical implication of these alterations, I will focus on how the results justify guitarist’s artistic decisions in Flamenco, Irish Traditional, and country/folk music. Understanding the connection between the technical and artistic aspects of the guitar can guide a musician in creating the effects appropriate for each genre.
Acoustic effects of varying the waist width of violin bridges: A physical experiment
Authors: Taft Benjamin N. , Taft Nathaniel
Published: April 2023

We explore the relationship between the bridge waist and sound production in the violin. Models of violin acoustics suggest that the stiffness of this portion of the bridge has a considerable effect on an instrument’s sound production. In practice, the proportions of the waist vary significantly from bridge to bridge and instrument to instrument, which suggests there are many ways that a luthier can influence a bridge’s stiffness. Our experiment connects modeling and real-world instrument sound adjustment. We incrementally remove material symmetrically from the bridge in the waist area, recording sound production at each increment. The bridges are destroyed in the process, which is repeated across multiple bridges. Sound stimuli include a sine wave at the bridge with dampened strings and a weighted bow drawn across freely ringing strings. We map changes in bridge geometry to changes in maximum output and acoustic measures of tone quality across several instruments. Since stiffness correlates with thickness, subject to the nature of the bridge material, there may be optimal shape adjustments for maximizing sound production, tone quality, or both.
Soundscape perception in a shifting context—Lessons from COVID-19
Authors: Jordan Pam , Fiebig Andre
Published: April 2023

The ISO-12913 standards acknowledge the primacy of context in perceiving acoustic environments. In soundscape assessments, context is constituted by both physical surroundings and psychological, social, and cultural factors. Many studies have found that people assess soundscape perception similarly in comparable physical surroundings (such as urban parks) despite differing individual associative contexts. However, studies at the Berlin Wall Memorial historic site have shown that providing historic contextual information to study participants can shift their soundscape perception away from the generalized baseline. The COVID-19 lockdown measures enacted in 2020 in Germany dramatically altered user activity in the memorial landscape, introducing a new environmental and behavioral context. Building on previous investigations at the memorial, this paper investigates what effect the restrictions had on the soundscape context and its perception by visitors. Informal interviews paired with comparative measurements indicated that expectations and perceptions shifted for local stakeholders in this new context. Perceived silence by visitors did not match measurements, and tourist absence affected perception for local users. This holds repercussions for soundscape and heritage site designs serving multiple populations with divergent expectations and perceptions. The impacts of soundscape assessments being neither static nor generalizable across stakeholders are discussed with suggestions for further research.
Using high-speed ultrasound to visualize dynamic jamming of dense suspensions
Authors: Jaeger Heinrich
Published: April 2023

A remarkable property of concentrated, or dense, suspensions comprising nanometer- to micrometer-size particles in a liquid is their ability to transform from a liquid-like to a solid-like state under applied stress. This jamming phenomenon can be triggered by impact at the surface of a dense suspension and generates a shear front that propagates into the bulk of the material. Tracking and visualizing such front is difficult because suspensions are typically opaque optically, and the front can propagate at several meters per second. This talk will discuss high-speed ultrasound imaging (10 000 frames per second) to extract the flow field associated with the front propagation and visualize the associated shear jamming process. Unlike densification in dry granular media, jamming by shear does not involve significant changes in the local particle fraction while driving the transition to solid-like behavior. On the basis of these findings, we discuss ideas that link the transient stress response of dense suspensions to current theoretical models, which almost exclusively focus on steady-state shearing conditions.
Maturation of cortical responses to sound in the first year of life
Authors: Lau Bonnie K. , Taulu Samu , Kuhl Patricia K. , Lee Adrian K. C.
Published: April 2023

Infants show sophisticated sound discrimination from the time they are born but the neural mechanisms that support infant auditory perception are not well understood. A central question is the discrepancy between the early onset of auditory skills and the protracted and extended maturation of the auditory cortex. To investigate the cortical processing of sound, we have been employing magnetoencephalography (MEG) with recent advancements in movement compensation to obtain functional neural measures of sound processing in awake infants. MEG responses from an Elekta Neuromag 306-channel system were recorded longitudinally at 3 (n = 27), 6 (n = 19), and 11 (n = 14) months to an ecologically salient bi-syllabic word and an amplitude-modulated complex tone pair in typically hearing infants. The neural generators of the MEG signals were determined using an equivalent current dipole (ECD) model. Our preliminary analyses have focused on two measures: cortical responses to acoustic change and the development of hemispheric lateralization to speech. Our preliminary analyses show that high quality MEG data with good signal-to-noise ratios can be obtained by 3 months and dipole modeling of MEG signals in combination with advanced movement compensation offers a temporally precise method of investigating the maturation of auditory cortical networks in infants.
Non-auditory processing of cochlear implant stimulation after unilateral auditory deprivation in children
Authors: Gordon Karen A. , Anderson Carly , Jiwani Salima , Polonenko Melissa J. , Wong Dan , Cushing Sharon , Papsin Blake
Published: April 2023

We have aimed to identify effects of unilateral hearing on the developing brain in a series of studies in children who have one deaf ear and access sound in the other ear through normal hearing, a hearing aid, or a cochlear implant (CI). Multi-channel EEG in these cohorts revealed strengthening of auditory pathways from the hearing ear to the auditory cortices. Response differences found in frontal and precuneus cortical areas in adolescents with long term unilateral CI use suggested involvement of non-auditory cortical areas during passive hearing. We also examined cortical effects of leaving one ear deprived of sound during development in children with unilateral hearing (listed above) who received a CI in their deaf ear. Atypical responses to CI stimulation showed strong activation of the ipsilateral auditory cortex which increased with duration of unilateral deprivation. Graph theory analysis including community detection revealed a network that was organised into a temporal-occipital module and a temporal-frontal module, with left Heschel’s gyrus and left lingual gyrus central to information flow between the two. Results across these studies identify neuroplasticity in children with unilateral hearing/deprivation and suggest that regions outside of the auditory cortex can modulate sound processing through CIs.
Fifty five years following a long and winding road through structural acoustics and vibrations
Authors: Ginsberg Jerry H.
Published: April 2023

Being an academic at institutions that did not have a dedicated mission in acoustics allowed me to pursue diverse research topics. Probably because of the challenge presented by structural acoustics and vibrations, my efforts were primarily focused in those areas. They proceeded from nonlinear shell theory, to pipeline instability, to nonlinear vibrations, to nonlinear acoustics, to variational methods for acoustic radiation, to shock response of submarines, to experimental modal analysis, to coupled acoustic-structure resonance of a flying telescope with an open cavity. I will attempt to attempt to explain what led me to this progression, and to place these efforts in the context of communal efforts.
Centering social justice in speech and hearing acoustics pedagogy
Authors: Munson Benjamin , Speights Marisha
Published: April 2023

Science can be seen as a collaborative activity designed to help humans be better adapted to the world that we find ourselves in and that we and our ancestors created. It is imperative that all scientists, including acousticians, create knowledge that helps all human beings, which acknowledges salient characteristics of the worlds we find ourselves in, and which highlights the human-created features of those worlds. This talk opens the special session by talking about three issues. We argue that there is woefully poor representation of the speech, language, and hearing (SLH) of people of color and of other marginalized groups. Studies of the normative behaviors of human beings are based on a woefully small and unrepresentative subset of languages and speech communities. We must also grapple with the consequences of our fields’ historical focus on the normativity of different speech and hearing behaviors. This involves interrogating what broader social structures benefit from a focus on normativity and pathologization. We argue that our field should follow the lead of Plaut (2010, Psych. Inquiry) in understanding not just differences in acoustic communication across individuals and groups, but differences in the perception of differences in SLH ability.
Addressing diversity in speech science curricula
Authors: Reed Paul E. , Baese-Berk Melissa M.
Published: April 2023

A fundamental understanding of speech science is a critically important component in fields such as linguistics, communication disorders and sciences, cognitive science, and speech technology. Therefore, courses in speech communication are integral to the undergraduate and graduate curricula of these and other subjects. Despite being at the forefront of pedagogical innovations, speech science courses have lagged in representing cultural and linguistic diversity in the classroom. Many speech scientists understand that linguistic diversity is fundamental to human language systems. However, discussions of language variation tend to be relegated to a single section within a course. The lack of inclusion of diverse language varieties results in a lack of engagement with many social variables such as race, ethnicity, and gender identity, among others. We argue that this “status quo” in speech science courses must change, such that linguistic diversity must be addressed in and throughout all courses, even those where diversity is not the focus. We will present concerns with current approaches to teaching about cultural and linguistic diversity. Furthermore, we will explain the benefits of including diversity instruction throughout the curriculum. Finally, we present specific recommendations for instructors to incorporate teaching of linguistic diversity throughout their curriculum and speech science courses.
Active cultural responsivity to terminology in speech and hearing science
Authors: Ancel Elizabeth
Published: April 2023

People are often the main focus of speech and hearing science. That being so, it is essential that scholars in the field recognize that all people are active participants in a larger sociocultural context. This context has an effect on how we refer to, describe, and study people from different backgrounds. Because of this, research and pedagogy in speech and hearing science have a responsibility to recognize and integrate this context into their practices. This presentation will focus specifically on the usage of terminology that describes different social and cultural groups. I will first review examples of the terminological history of a few commonly encountered groups. This section will also serve as a practical resource for the current best practices for terminology usage in accordance with the groups’ preferences. Then, I will provide general recommendations for being culturally responsive to terminology usage in research and in the classroom, with examples from common topics taught in speech and hearing science classes.
Building an understanding of sampling and filtering
Authors: Nelson Jill K.
Published: April 2023

While signals and systems homework problems often focus on giving students practice in procedures and computations, some of the problems I most enjoy are those that ask students to step away from familiar procedural approaches and think outside the box. In this talk, I will describe three problems that encourage conceptual thinking about sampling and filtering. In the first, which focuses purely on sampling, students are asked to determine how various operations on a generic signal change its Nyquist sampling rate. The second problem asks students to consider how aliasing may be allowable (and even desirable) when sampling will be followed by discrete-time filtering. The final problem asks students to characterize a sampler followed by a discrete-time system based on observation of the input and the output, which requires students to tease apart the effects resulting from sampling and those resulting from filtering. These three problems are drawn from signals and systems material I have encountered over many years of teaching and through a variety of sources. I appreciate the way they encourage students to think of sampling and filtering as tools that can be used creatively rather than as a prescribed series of steps.
Project-based learning engages students at a level more directly applicable to their future careers
Authors: Singer Andrew C.
Published: April 2023

Some of my favorite homework problems are not homework problems at all, but, rather, more open-ended project-based assignments that elevate students' thinking toward the top of Bloom's Taxonomy. While some students may have the background to jump into a project-based assignment, most benefit from an increasing level of scaffolding. This not only brings all students to a common level from which they can develop a more coherent project, but it also provides multiple opportunities for them to solidify their understanding and build on curated, worked examples. This talk will explore two different types of courses, one theory-based and one experiential, each benefiting from a scaffolded framing for a more open-ended signal processing or data analysis project.
Design and implementation of a least-mean-square adaptive notch filter
Authors: Ali Randall , Rosseel Hannes , van Waterschoot Toon
Published: April 2023

The task of removing sinusoidal components from observed signals can be accomplished by using a notch filter with a specific attenuation at a particular frequency. In some applications, however, such as acoustic feedback control, the frequency at which attenuation is required is unknown and possibly time-varying, and hence an adaptive notch filter is a more appropriate solution. Transitioning from a fixed notch filter to an adaptive one is by no means trivial and involves the understanding of a range of digital signal processing (DSP) topics from pole-zero placement techniques for designing infinite impulse response filters to optimal and adaptive filtering algorithms. In the signal processing algorithms and implementation graduate course taught at KU Leuven (Belgium), we study the design of an adaptive notch filter, which is based on a constrained biquadratic IIR representation, andwhose parameters are updated using a least-mean-square algorithm. Students also have to implement the algorithm on a 16-bit DSP TMS320C5515. In this presentation, we will discuss the design and implementation challenges of this adaptive notch filter and how it serves as an illustrative example/homework problem where several aspects of DSP are interwoven.
Inclusion of three dimensional acoustic propagation in nuclear event characterization
Authors: Heaney Kevin D. , Coelho Emanuel F. , Zampoli Mario , Oliveira Tiago , Haralabus Georgios
Published: April 2023

The verification regime of the Comprehensive Nuclear-Test-Ban Treaty is the International Monitoring System that includes deep-water hydroacoustic stations for monitoring the world oceans for nuclear tests. As underwater sound propagation satisfies the acoustic wave equation, it is subject to three-dimensional (3D) effects (refraction, diffraction, reflections) when in the presence of horizontal gradients due to bathymetry, oceanography, or the presence of continents. The current processing system does not exploit these 3D effects, because it relies on in-plane propagation for all acoustic paths, which may lead to azimuth errors for event association. In this work, a set of acoustic propagation codes are being proposed to integrate 3D propagation into the automated event localization algorithm as well as into the analyst work flow. A summary of the acoustic models, demonstrations of observed 3D phenomenon for large underwater events, as well as a program plan to update the processing scheme will be presented.
Comparison of semi-analytical and numerical methods for the scattering of acoustic waves by rough, sloped seabed geometries
Authors: Whitchelo Yiyi , Haslinger Stewart , Colquitt Daniel , Williams Duncan
Published: April 2023

The seabed possesses variations in its material properties, layering structure, slope and roughness making prediction, and analysis of sound propagation in shallow water highly complex. For certain frequency ranges, the effect of roughness becomes significant. Numerous models have been adopted to account for the scattering of acoustic waves by rough surfaces, including Kirchhoff approximation (for relatively large scales of roughness), small perturbation theory (for relatively small scales of roughness), and small slope approximation, which bridges across the two regimes under certain conditions. Although grounded in analytical theory, these approaches invariably involve the computation of numerical integrals so additional approximation theories have been explored including stationary phase methods and Taylor series approximations. In this study, these semi-analytical methods are incorporated within a new sound propagation model and compared with a numerical graphics processing unit (GPU)-accelerated finite element model incorporating roughness parameters (root mean square height and correlation length) for rough, sloped seabed geometries (with gradients ranging from 0° to 45°) in shallow water environments. The effect of large- and small-scale roughness on sound propagation is investigated in two- and three-dimensional space. The finite element modelling is used to validate the optimal choice of semi-analytical method for the different environments considered.
Modeling shallow water scattering from rippled seabed in the Long Island Sound
Authors: Gunderson Aaron M. , Kidwell Autumn
Published: April 2023

A high frequency (HF) AUV-mounted forward-looking sonar deployed in the shallow Long Island Sound recorded acoustic scattering measurements from large bedform ripples. The axis of transmission was horizontal and laterally oblique to the ripple plane, but at wide horizontal aperture, so that broadside scattering from the ripples was believed to be a significant contributor to the scattering return. The effects of the ripples are explored through finite element model evaluation and comparison. In this study, the seafloor ripples are orders of magnitude larger than the acoustic wavelengths used in the survey. In plane and out of plane, scattering effects are considered, as well as the effects of ripple asymmetry. Modeling techniques for dealing with high frequency systems over large physical distances are discussed. [This work was supported by the Office of Naval Research, Littoral Geosciences and Optics.]
Ray tracing of long-range underwater acoustic vortex wave propagation
Authors: Kelly Mark , Shi Chengzhi
Published: April 2023

The underwater acoustic communications environment is severely band-limited, which leads to a bottleneck in data transfer. Existing methods of data transfer in underwater acoustic communications applications typically rely primarily on conventional temporal and frequency modulation techniques and achieve bit rates peaking at approximately 40 kb/s. One method of easing the bottleneck and increasing the data rate is to explore further potential degrees of freedom which may be utilized. Acoustic orbital angular momentum (OAM) is a physical quantity that characterizes the rotation in a propagating helical pressure wavefront. The unique phase patterns of OAM carrying vortex waves form an orthogonal basis which may be useful as an additional degree of freedom in acoustics communications applications; however, the long-distance propagation of these waves is largely unstudied. By employing BELLHOP’s ray tracing algorithm, the dominant features of a propagating OAM carrying vortex wave are tracked over long ranges (to and beyond 1 km) under various environmental conditions. This provides essential guidance in the design of the sending and receiving arrays of high-speed underwater communications systems, which rely on multiplexing acoustic OAMs.
Numerically modeling the sound absorption behavior of 3D printed fibrous absorbers
Authors: Lomte Amulya , Johnston Will , Sharma Bhisham
Published: April 2023

Recently, we have demonstrated the feasibility of using extrusion-based additive manufacturing methods to fabricate fibrous sound absorbers [1]. Here, we investigate the feasibility of predicting the sound absorption behavior of such structures by extracting their geometry-based transport properties using the hybrid, multiphysics modeling approach. The acoustical transport properties are calculated by modeling the fibrous unit cell and solving three boundary value problems over the representative elementary volume of the periodic fluid domain. Our results show that the absorption predictions obtained using the as-designed unit cell significantly differ from the experimental measurements obtained using conventional two-microphone impedance tube tests. Further investigations conducted using an optical microscope reveal that while the printed fiber diameter remains uniform over its central portion, the fiber diameter decreases drastically near the fiber root. Finally, we show that incorporating these geometrical differences within the model improves computational predictions and accounts for the deviations between the numerical and experimental absorption coefficients. [1] Johnston W, Sharma B. Additive manufacturing of fibrous sound absorbers. Additive Manufacturing. 2021 May 1;41:101984.
Testing the absorption coefficient of 3D printed perforated panels
Authors: Zusin Elizabeth G. , Riegel Kimberly A.
Published: April 2023

Sound absorption is common in most studios, but most residential spaces are not designed for good acoustics. While these rooms are non-ideal, they are sometimes used to record sounds and need to absorb unwanted frequencies. Perforated 3D printed panels have the potential to make inexpensive and modular home treatments. In order to determine if these panels would be effective, the absorptive properties need to be evaluated. There are several ways to test sound absorption, including the in situ subtraction method and the impedance tube transfer function method. Reference materials were used to test the effectiveness of both measurement methods. 3D printed perforated panels were then designed and the absorption was tested. Each surface was tested with the subtraction method, and many different setups for the equipment were tested to find the ideal setup for the most accurate absorption coefficient. The results show varying success. The 3D printed panels were then tested with the transfer function method. An impedance tube was made using PVC pipes and was used to test the transfer function method. This method showed varying results for the absorption coefficient tested, and results will be presented.
Archaeoacoustic measurement and simulation of the Jesuit Chapel at St. Mary’s City, Maryland
Authors: Boren Braxton
Published: April 2023

St. Mary’s City, Maryland was the original capital of Maryland, founded as a colony with protections for Catholics by Lord Baltimore. As a result of the colony’s religious toleration, the city built a permanent Jesuit chapel, the earliest brick structure in Maryland, in 1667. The chapel was one of the earliest brick worship spaces in America, and the only permanent Catholic worship space in the English-speaking world. When Protestants later took control of the state and moved the capital away, the chapel was closed by the governor, and the Jesuits recycled its materials into other structures. As part of archaeological excavation and heritage preservation efforts at St. Mary’s City, the Jesuit Chapel was rebuilt according to historic building practices and materials in the 2000s. The reconstructed chapel was known for its pleasant acoustics by many in the area, and impulse responses were measured in the rebuilt space. The measurements were used to calibrate a geometric acoustic model of the space, which is used as a starting basis for the acoustics of the original 1667 chapel. Some discussion is given to the role of physical versus virtual reconstruction in heritage acoustics and archaeoacoustic projects.
Bridging the gap: Sound as a tool towards resettlement
Authors: Hosseini-Mozari Milad
Published: April 2023

Over the past three years, various sound initiatives have been conducted in a collaboration between the College of Architecture and Planning at the University of Utah, and the International Rescue Committee (IRC). Led by Milad Mozari, an artist and researcher, the medium of sound is used as a tool for exploration, place-making, and spatialization between students and refugees. This paper presentation will go over three categories of how audible sound is used in this collaboration. (1) The use of omnidirectional microphones to create sound collages as a way of introducing a place. This was distinctly differently interpreted in proximity to sound sources by students and IRC clients. (2) Experiments in analog synthesis to create collaborative performances between individuals with different musical backgrounds. (3) The use of ambisonic mixing for virtual reality videos that former IRC clients and students create as a tool for the resettlement of future refugees. Overall, this ongoing initiative is at the intersection of social design and emerging technological tools, which marginalized communities are often unaware of. At its core concept, the project aims to increase accessibility to sound tools to communities that may not come across it in their resettlement process.