bluuebunny/crossref_metadata_2025 huggingface dataset:
Tongue position variability in sustained vowels produced by healthy children and young adults with and without a semi-occluded vocal tract: A pilot study
Authors: Lulich Steven M. , Diekhoff Megan , Patel Rita R.
Published: November 2021

Speech development is a process by which talkers learn, among other things, to coordinate neuromuscular activations of motor units spread across several muscles that effect articulator positioning and movement. This paper presents results from an analysis of tongue position variability during sustained vowel production. Data from two children (7 years 11 months, and 9years 7 months) and two young adults (both 20 years 7 months) are presented. Articulatory data were recorded with a 3D/4D ultrasound system, in two conditions: without a semi-occluded vocal tract (“without straw”) and with a semi-occluded vocal tract (“with straw”). Statistical analyses of tongue position variability revealed a main effect of age, with children showing greater variability than adults. There was no statistically significant main effect of condition, but the main effect of age was driven primarily by the “with straw” condition. We speculate that tongue position variability during sustained vowels may be an index of speech motor control maturity, and that the interaction between age and condition suggests children are less able than adults to rely on learned feed-forward motor programs under conditions of somatosensory perturbation, such as the presence of a straw between the lips.
Telepractice effects: Vowel space characteristics in deaf and hard-of-hearing pediatric patient, provider and caregiver speech
Authors: Kondaurova Maria V. , Donaldson Cheryl W. , Zheng Qi , Pike Elizabeth
Published: November 2021

When talkers are aware of speech perception difficulty on the part of the listener due to adverse conditions, they will adopt a “clear speech” style that provides the listener with more salient acoustic cues to access and comprehend the message. Does the use of telepractice affect the vowel articulation in deaf and hard-of-hearing (DHH) pediatric patients, providers and caregivers? This study examined the phonetic modification of the vowel space area in speech of DHH children with cochlear implants (CI) (n = 7, mean age 4 years 11 months), their caregivers and a speech-language pathologist (SLP) during one 30-min in-person and one sequential tele-session, order counterbalanced. The first and second formants of vowels /i/, /a/ and /u/ in child, provider and caregiver productions were measured and vowel space area was calculated. The preliminary analysis including four child-mother dyads demonstrated a significantly larger vowel space area in speech of DHH children and the SLP in the tele- compared to the in-person session. No significant difference in the caregiver vowel space area was identified. The results suggest that DHH children and the clinical provider adjust their vowel articulation in order to accommodate the listener during tele- compared to in-person speech-language intervention.
Role of training task on learning and maintenance of noise-vocoded speech
Authors: Drouin Julia R. , Theodore Rachel M.
Published: November 2021

Listeners who utilize cochlear implants demonstrate variability in speech recognition outcomes. Experience with the auditory signal via structured auditory training has been shown to improve speech perception. A primary goal of aural rehabilitation is optimizing training paradigms to maximize speech understanding gains observed following training. The current study examined the role of the training task on adaptation to noise-vocoded speech signals as a foundational step towards clinical recommendations for cochlear implant users. Three groups of listeners were assigned to one of three training tasks: transcription with feedback, transcription without feedback, or talker identification. All listeners completed transcription test phases before training, immediately after training, and one-week following training. At each test, keyword accuracy was measured at the sentence-initial and sentence-final position for high and low-predictability sentences. Immediately following training, listeners showed improved transcription for both sentence positions, which was mediated by sentence predictability, and learning was comparable across training tasks, in line with previous findings. Critically, gains were also maintained equivalently among training groups one week later. Our results converge with growing findings pointing towards utilizing non-traditional training tasks to maximize perceptual learning of noise-vocoded speech and point towards rehabilitation considerations for cochlear implant users.
Early evidence of cognitive involvement during sensorimotor integration for speech
Authors: Hebert Karen , Dayalu Vikram , Grabowski Caryn , Patel Sona
Published: November 2021

Executive functioning is fundamental to motor processes that involve decision-making, and yet, the role of cognitive control during speech production is not well understood. The purpose of this study was to examine the relationship between auditory attentional decision-making ability and changes in acoustic parameters and speech error rates during sensorimotor integration for speech production. Seventeen healthy individuals first completed an auditory analog of the Attentional Network Test to assess attentional decision-making and then read passages under delayed auditory feedback (DAF). None of the acoustic parameters (speech rate, mean and standard deviation of fundamental frequency and intensity) were related to metrics of cognitive processing. However, auditory processing speed, measured as reaction time to pitch identifications (r = -0.58, p < 0.05) and auditory location identifications (r = -0.66, p < 0.05), was significantly related to the total number of dysfluencies (across articulation errors, stuttering-like disfluencies, and other disfluencies) under DAF. In other words, individuals who made quick auditory discriminations produced more dysfluencies under DAF. While preliminary, these findings suggest that cognitive functions including executive control are engaged during speech production. These findings can be understood in the context of diffusion models of decision-making and the impact of cognition on speech perception.
Learnability of ultrasound tongue imaging devices in speech-language pathology
Authors: Marcoux Isabelle , Ménard Lucie , Laporte Catherine
Published: November 2021

Ultrasound tongue imaging has shown potential for speech-language pathologists (SLPs) to evaluate and treat persistent articulatory disorders. However, SLPs typically begin with low to no familiarity with ultrasound. Thus, this study investigated an important aspect of ultrasound device usability: learnability for SLPs. The project was funded by an NSERC Engage grant in partnership with Clarius Mobile Health. 12 SLPs learned to use two ultrasound devices: a wireless device, provided by our partner Clarius, and a traditional device, to record clips of their or the experimenter’s tongue. They then completed a questionnaire [French translation of the System Usability Scale (Brooke, 1996)]. Two expert judges evaluated the clips recorded by the SLPs for the choice of settings and the positioning of the probe. Results of the SUS show a better usability for the wireless device than the traditional device. SLPs appreciated the user-friendly tablet interface, possibly because they are already used to interacting with tablets. Clips analyses show a better choice of settings by the SLPs with the wireless device. The positioning of the probe, however, was better with the traditional device, possibly due to its smaller probe. In conclusion, US seems to have a good potential of usability in speech-language pathology, provided that SLPs receive training for US image interpretation. A traditional US device may require a longer learning period than a wireless model with tablet interface.
Prosodic characteristics of English speakers with Alzheimer’s disease
Authors: Ebbutt Nicole , Shamei Arian , Purnomo Charissa , Gick Bryan
Published: November 2021

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder. A large amount of work has focused on the automatic detection of AD, but few have examined the underlying acoustic correlates. Through the analysis of 42 speakers (21 AD and 21 control), research by Martinez-Sanchez et al. have reported flattened pitch trajectories which distinguish Spanish-speaking AD patients from those of controls [Martinez-Sanchez et al., Psicothema 24(1), 16–21 (2012)]. The present study aims to determine whether a similar effect is found in a large-scale study of English speakers with AD. Prosogram [Mertens, in Proceedings of Speech Prosody (2004)] was used to assess pitch trajectories of 203 English-speaking participants (128 AD and 75 control) from Dementiabank’s Pitt Corpus [Becker et al., Arch. Neurol. 51(6), 585–594 (1994)]. AD patients exhibited greater pitch range and trajectories across phonation than controls, both within and across syllables. These preliminary findings conflict with previous observations of a flattened prosodic profile for AD patients. A possible reason for this discrepancy is a difference in speech elicitation tasks. Previous studies on Spanish-speakers used reading and delayed pronunciation tasks, whereas the present study utilizes a picture description task, a more natural elicitation method.
Effects of word frequency and phonological neighborhood density on speech recognition in background noise and competing speech
Authors: Whittle Nicole , Herrera Ortiz Christian , Leek Marjorie R. , Heidrich Jerome , Jenkins Mark , Venezia Jonathan H.
Published: November 2021

Clinical speech-in-noise tests typically use materials without contextual constraint or balanced for linguistic properties like word/phoneme frequency. However, real-world linguistic context effects can be substantial and vary by listener and scenario. Here, 38 participants completed the Theo-Victor-Michael (TVM) speech test in four types of background: speech shaped noise (SSN), speech-envelope modulated noise (envSSN), one competing talker (1T), and two competing talkers (2T) (Helfer and Freyman, 2009). The TVM is a matrix test using keywords from a corpus of one- and two- syllable nouns that vary considerably in word frequency (FREQ) and phonological neighborhood density (DENS). Bayesian logistic regression was used to estimate the effects of FREQ/DENS on TVM performance. A multinomial model was used for 1T/2T to assess reporting of target and distractor keywords. Overall, percent-correct recognition increased with increasing keyword FREQ and decreased with increasing keyword DENS. Effects were larger in SSN/envSSN than 1T/2T. Statistically significant but small effects of FREQ/DENS were observed on distractor responses in 1T/2T. Adjusting performance for FREQ/DENS substantially shifted the distribution of scores but only for SSN/envSSN. Performance in 1T/2T may be dominated by non-linguistic factors, and/or less sensitive to FREQ/DENS due to higher difficulty or linguistic competition from the background talkers. [Work supported by VA RR&D Service.]
Real-time, model-aided ranging for small scale operations in the Beaufort Sea, an ice-covered, double ducted environment
Authors: Bhatt EeShan , Viquez Oscar A. , Howard Bradli , Schmidt Henrik
Published: November 2021

This talk will cover operational methods and results for vehicle navigation from the Ice Exercise in March 2020 (ICEX20), in the Beaufort Sea. For short range acoustic transmissions, the total ice cover and the double ducted environment co-create complex multipath uncertainty. We assumed that the horizontal group velocity between source and receiver was smoothly varying, and embedded a “Virtual Ocean” with a real-time ray tracing engine to predict the horizontal group velocity for range estimation. This model-aided psuedorange approach, which enabled a successful vehicle recovery, favored the least multipath possible such that psuedoranges tended to overestimate the GPS-derived range by roughly 10 m. In post-processing, we modify the group velocity estimation method to consider varying degrees of multipath and achieve a mean absolute error of roughly 4 plus or minus 4 meters, rivaling GPS performance. To our knowledge, these results are the first field experiment to demonstrate a real-time, model-based data processing to constrain ranging error for underwater navigation. [Work supported by ONR & the NDSEG fellowship.]
Moving source tomography with controlled source-tow observations
Authors: Gemba Kay L. , Vazquez Heriberto , Sarkar Jit , Tippman Jeffrey D. , Cornuelle Bruce , Hodgkiss William , Kuperman William
Published: November 2021

A moving source tomography experiment was conducted in 2016 off the coast of Southern California. From the travel time data extracted from the experiment, ocean sound speed and its uncertainty were estimated. The moving source poses extra complexity and adds components that need to be accounted for in a successful inversion. The sound speed estimation with uncertainties was validated against in situ observations to quantify the efficacy and accuracy of the method. Experimental results and additional simulations suggest that the ray diversity available in the moving source case reduces the posterior sound speed uncertainty compared to the fixed source case. [Work sponsored by the Office of Naval Research.]
Clustering of sperm whales recorded by a single hydrophone
Authors: Drouant George , Ioup Juliette W.
Published: November 2021

Sperm whales (Physter macrocephalus) produce echolocation clicks composed of several pulses while searching for food when diving. The clicks are composed of segments three of which are: the p0 pulse (3 kHz to 15 kHz), the p1 pulse (3 kHz to 15 kHz), and the Low Frequency (LF) signal (<3 kHz) (Zimmer, 2005). The LF signal is omnidirectional in nature unlike the p1 pulse which is very directional. The power in the LF signal recorded by a single hydrophone is a function of the distance of the whale from the hydrophone and the source level of the whale. The power contained in the LF portion of the clicks can be used to assign clicking whales to groups with each group consisting of a least one individual. The inter-pulse interval (IPI) can then be used to determine the lengths of the whales in each cluster adding confidence to the estimated number of whales producing the clicks. Continuous Wavelet Transforms are used with underwater acoustic data recorded in the Gulf of Mexico in 2015 to determine the power of the LF signal, the length of the clicking whale and the alignment of the acoustical axis of the whale with the hydrophone.
Waveguide Invariant-based mitigation of reverberation and interference in active and passive sonar
Authors: Krolik Jeffrey
Published: November 2021

Multipath propagation poses many challenges for broadband sonar signal processing in underwater acoustic channels. The waveguide invariant (WI) provides a useful relation between the temporal and frequency fading characteristics in shallow-water channels that can been exploited to improve broadband target detection in both active and passive sonars. In active sonar, the WI motivates an alternative to conventional constant-false-alarm rate (CFAR) normalization of the background by averaging over observed time-frequency striations to estimate the reverberation level. A WI-based generalized likelihood ratio test is reviewed and shown to outperform conventional cell-averaged and frequency-invariant CFAR detectors in both simulation and with real Mediterranean data. In passive towed-array sonar, targets near endfire are often masked by angularly spread broadband multipath interference whose statistics must be estimated with limited training data for effective suppression. A WI relationship characterizing the frequency-dependence of wavenumber differences permits averaging of narrowband array snapshots to form a low-rank broadband “focused” covariance matrix. Simulation experiments in a realistic ocean environment are reviewed showing that adaptive beamforming using WI focused covariance matrices can provide a significant array gain improvement over conventional adaptive methods with limited observation time. Finally, the potential for waveguide invariant-based blind source separation is discussed. [Work supported by ONR.]
Environmental probing using waveguide invariant
Authors: Turgut Altan
Published: November 2021

In continental shelves, barotropic tides, internal tides, and nonlinear internal waves could potentially be monitored using acoustic waveguide invariant theory. When temporal variability of broadband acoustic signals is measured along a fixed track, frequency shifts of constant acoustic-intensity level curves can be used to capture temporal behavior of these oceanographic processes. In addition, acoustic intensity striations generated by a towed source or a ship of opportunity could be used to estimate seabed properties. The feasibility of environmental probing for the oceanographic processes and sediment types is discussed in terms of the available group of acoustic modes, frequency bands, and experimental geometries. Several experimental measurements and broadband numerical modeling results are provided to assess the limits of each probing method under winter and summer conditions. [Work supported by the ONR.]
Extraction of seabed properties in mid-frequency range using waveguide invariant applied to broadband signals
Authors: Badiey Mohsen , Wan Lin , Escobar-Amado Christian D.
Published: November 2021

One of the fundamental problems in shallow water environments is to assess the seabed properties. The waveguide invariant can be used in both passive and active sonar processing, source ranging, time reversal focusing, and in geoacoustic inversion processes. In Pekeris waveguide, the waveguide invariant value is approximately 1 and the slope of the interfering acoustic intensity fringes relates to the bottom sound speed. Using the slope of the striations as a variable, the spacing of the interference in range (or frequency) can be related to the penetration of energy into the bottom. The depth given by spacing of real arrivals has an effective depth of penetration which depends on the geoacoustic properties of the bottom sediments. Here, we study the frequency dependence of the waveguide invariant due to sediment layer structure and physical properties and provide a detailed data/model comparison for a shallow water range independent waveguide and extract the seabed properties for the frequency band 1.5 to 4.0 kHz using recent data obtained in shallow water environments. [Work supported by ONR 321OA.]
Range estimation of a distant ship using a vertical array and a guide ship
Authors: Byun Gihoon , Song Heechun
Published: November 2021

In this talk, we present a method for estimating the range of a distant ship in shallow water using a vertical array and a guide ship at a known range close to the array. The method involves a combination of four well-known approaches: (1) blind deconvolution; (2) waveguide invariant; (3) virtual receiver; and (4) array invariant. The main idea is to transform theoriginal task of estimating the range of a distant ship using a vertical array into estimating the range with a synthesized horizontal array aroundthe guide source exploiting the waveguide invariant theory. The proposed method is demonstrated for a surface ship radiating broadband noise (100–500 Hz) at 10 km range, using a 56.25-m long vertical array in approximately 100-m water and the same ship at 2 km range as the guide ship.
The waveguide invariant for a Pekeris waveguide
Authors: Song Heechun , Byun Gihoon
Published: November 2021

A closed-form waveguide invariant β for a Pekeris waveguide is derived. It is based on the modal Wentzel–Kramers–Brillouin (WKB) dispersion equation and implicit differentiation, in conjunction with the concept of the angle-dependent “effective boundary depth,'' ΔH(θ). First, an explicit expression for β(m,n) between mode pairs is derived assuming an ideal waveguide of the effective waveguide depth H+ΔH(θ), which provides an excellent agreement with the exact value calculated for the Pekeris waveguide of depth H using KRAKEN. Then, a closed-form expression for a group of adjacent modes is derived: β = (H + ΔH)/(H/cos2θ − ΔH), which reduces to β = cos2θ as ΔH/H ≪ 1, the analytical expression for an ideal waveguide. For applications to source-range estimation, the waveguide invariant β is used to derive the theoretical beam-time migration (i.e., dispersion curve) in a Pekeris waveguide.
Tracking killer whale movements in the Alaskan Arctic relative to a loss of sea ice
Authors: Kimber Brynn , Harlacher Jenna , Braen Eric , Berchok Catherine
Published: November 2021

Killer whales (Orcinus orca) are highly intelligent and versatile predators. Though they have a consistent presence in southern Alaskan waters, they are not known to frequently or consistently venture into the typically ice-covered U.S. Arctic, where they risk ice entrapment. However, with the trend of decreasing sea ice in the Arctic Ocean, these top predators may be venturing into waters that were previously inaccessible to them. To expand our knowledge of killer whale movements in the Arctic, eight years of data (2010–2018) from four AFSC passive acoustic moorings (funded by NOAA S&T, the U.S. Navy, and BOEM) located in the Chukchi, Beaufort, and northern Bering Seas, were manually analyzed for the presence/absence of killer whale signals to examine interannual trends in the acoustic presence of killer whales. Results from our data indicate that killer whales spend more time than previously recorded in the Arctic, as far as the edge of the Chukchi Borderland, directly following the decrease in sea ice in these areas. These results speak to a changing Arctic, both in terms of the presence of killer whales themselves and in terms of the impact that increased killer whale predation could have on Arctic food webs.
Echolocation click characteristics of two fish-eating killer whale populations
Authors: Wladichuk Jennifer , Lawson Jack , Dosso Stan , Koblitz Jens
Published: November 2021

Acoustic disturbance has been identified as a threat to the survival of the endangered Southern Resident killer whale (SRKW) population whose critical habitat in the Salish Sea overlaps with busy commercial shipping lanes and popular recreational boating areas. Vessel noise has the potential to mask important sounds used by the whales for navigating, communicating, and foraging. To investigate the impact on foraging, acoustic characteristics of the whales’ echolocation clicks must be known. We collected data on SRKW in the wild using a 2 × 2 m2 23-hydrophone array deployed at short ranges (<500 m). We also acquired data on a neighboring population of Northern Resident killer whales (NRKW), whose numbers are increasing. Comparable results were obtained for most parameters between the two populations. Average peak-to-peak apparent source levels were 203 and 196 dB re 1 μPa at 1 m for SRKW and NRKW, respectively. The two populations had similar mean centroid and peak frequencies ranging between 26–29 kHz and 19–21 kHz, respectively. However, root-mean-square bandwidths differed significantly between the populations, with averages of 52 and 39 kHz for SRKWs and NRKWs, respectively. These results will be used to investigate masking potential under varying ambient noise conditions.
Orcasound: Open source software for catalyzing conservation of endangered Southern Resident killer whales in real-time
Authors: Veirs Scott , veirs val
Published: November 2021

Over the last 20 years, Orcasound has evolved from a cooperative network of real-time hydrophones to an open source software and hardware project. Orcasound connects cabled hydrophones deployed in critical habitat of the Southern Resident killer whales (SRKWs) with a web app that enables community scientists to listen and tag audio data in real-time. The live audio feeds are also monitored by automated algorithms (e.g., OrcaHello), archived in Amazon data “buckets” which are publicly accessible for free and governed by a Creative Commons license that promotes non-commercial data sharing and specifies appropriate attribution. Many of these open data have been annotated through crowd-sourcing tools built by the Orcasound community, like Pod.Cast and OrcaAL, generating open test and training data sets needed for development of more advanced classifiers. We present the latest version of Orcasound’s live-listening app as a novel conservation tool, and describe our evolving architecture for: generating audio streams with low-cost hydrophones and hardware, and free software; deploying diverse algorithms, including on non-Orcasound hydrophone data streams; validating, annotating, and analyzing acoustic detections; aggregating them in an open data cooperative along with regional data from sighting networks; and issuing notifications to network members as well as conservation stewards.
Recent developments, observations and lessons learned in the use of real-time passive acoustic monitoring from ocean gliders in order to mitigate harm to North Atlantic Right Whales and Southern Resident Killer Whales
Authors: Moloney John E. , Kowarski Katie , Martin S. B. , Gaudet Braind , Cole Art , Maxner Emily
Published: November 2021

JASCO’s novel passive acoustic monitoring (PAM) system, OceanObserver was deployed in Canada’s Gulf of Saint Lawrence (GoSL) in autumn 2018 aboard a Slocum G3 glider. The purpose of this mission was to assist in the search for endangered North Atlantic Right Whales and other threatened cetaceans, and to report detections in near-real-time so that appropriate mitigation actions could be taken. This proposed presentation will provide results and lessons learned based upon the rigorous analysis and comparison of the real-time, in situ detections with the automated and manual detections derived from post-trial analysis of the recorded raw acoustic data. This post analysis has permitted an assessment of the performance of the automated detectors deployed at sea and the effectiveness of the real-time communication management software in getting marine mammal detections to shore-based stakeholders in a timely manner. It also has permitted the evaluation of the effectiveness of shore-based acoustic analysts tasked with the validation of the automated detections sent to shore.Whether the mission objective of “no false positives” in order to ensure the correctness of mitigation decisions will be discussed. The method of assessing performance will be described and empirical results presented. The application of this technology to SRKW conservation will be discussed.
Muscle elastography: Stress versus stiffness
Authors: Crutison Joseph , Klatt Dieter , Sandercock Thomas G. , Perreault Eric J. , Royston Thomas
Published: November 2021

Dynamic elastography imaging, whether based on magnetic resonance, ultrasound or optical modalities, attempts to reconstruct quantitative maps of the viscoelastic properties of biological tissue, properties that are altered by disease and injury, as well as response to therapy. Reconstruction often assumes isotropy and homogeneity and neglects the effects of nonhomogeneous boundary conditions. Skeletal muscle violates all these assumptions, posing challenges and opportunities for developing better imaging biomarkers. Muscle activation and varying tensile loads can influence measurement interpretation. For bulk shear waves in an isotropic viscoelastic material not influenced by boundary conditions the measured wavelength correlates with the square root of the tissue’s shear elastic modulus and viscosity, important rheological parameters. But, under significant tensile loading the measured transverse wavelength will also be affected by the induced quasistatic stress field, making identification of the muscle’s inherent rheological properties seem impossible. Acoustoelastic theory, previous studies addressing this issue specifically for muscle, as well as new studies by our group are reviewed, identifying remaining challenges, potential strategies and opportunities for a more comprehensive understanding of both muscle structure and function based on noninvasive measurements. [Support acknowledged: NSF #1852691, NIH #AR071162.]
Role of anisotropy in elastographic tissue characterization
Authors: Urban Matthew W. , Pelissero Maureen , Liu Hsiao-Chuan
Published: November 2021

The structure and function of soft tissues are intimately connected. Some soft tissues are organized in such a way that they have material properties that are anisotropic, that is, the measured properties depend on which direction they are measured. Some such tissues are the brain, kidney, arteries, and cardiac and skeletal muscle. We will provide a brief overview of work targeted at characterization of the anisotropic mechanical properties in kidney and cardiac and skeletal muscles. In many cases, these tissues can be assumed to be transversely isotropic, which allows for simplification in estimating their mechanical properties. The use of propagating shear waves can be used to determine these mechanical properties. As a comparison example, we will show data from characterization of renal tissue with ultrasound shear wave elastography (SWE) and optical coherence elastography. We will also provide an overview of evaluation of skeletal muscle mechanical properties using shear wave elastography techniques and use of model fitting to estimate mechanical properties. Special care must be taken in evaluation of such anisotropic tissues to ensure that measurements are standardized across practices and studies.
Acoustics and vibrations as an integral part of the engineering curriculum at the University of Hartford
Authors: Jasinski Christopher M. , Celmer Robert
Published: November 2021

The University of Hartford is home to two unique undergraduate engineering majors in acoustics, both sharing a core course layout of acoustics, vibrations, and projects. These include Vibrations 1/2, Fundamentals of Architectural and Musical Acoustics, Acoustics by Design (Project), Advanced Acoustical Topics, and Acoustic Capstone Design Project. The B.S.M.E. with Acoustics Concentration and the B.S.E. in Acoustical Engineering and Music programs allow for two different tracks within the acoustics field, providing cohesive plans of study on many facets of listening and design. Additionally, all Mechanical Engineering majors are required to take Vibrations 1, and a course in Engineering and Environmental Acoustics. The department philosophy for this inclusion is that acoustics and vibration considerations are an essential component for the development of the complete mechanical engineer. Examples of the wide range of career paths that program graduates pursue will be addressed. This presentation will discuss the details and history of the acoustics program, components of the Vibrations I and Engineering and Environmental Acoustics courses, example research and design projects based on work in these courses, and a review of educational goals and outcomes, along with pedagogical development of a unique Vibrations Concept Inventory for assessment.
Comics and acoustics education: A drawn example around the decibel
Authors: Robin Olivier
Published: November 2021

While having been the object of various criticisms and considered to be a childish litterature for a long time, comics are now a legitimate art form, the ninth art. Comics are also considered as a fully fledged tool for disseminating and explaining science. More and more researchers advocate for a larger use of comics in science, and creating comics is generally found to have a positive effect on students. This presentation will first briefly recall main facts concerning comics, and their use in dissemination and education. The genesis of an educational “comics paper” explaining the origin and history of the decibel, together with examples from acoustics and other domains will be then thoroughly described. This “comics paper” will be put into perspective with its companion “classical paper,” in order to appreciate the transition from an almost exclusively written form to a predominantly drawn form.
Using Impedance to explore resonance in mechanical, acoustical, and electrical analog systems
Authors: Russell Daniel A.
Published: November 2021

Resonance is usually defined as the frequency at which a measured quantity reaches a maximum value with any change in frequency resulting in a decrease in the amplitude of the measured quantity. Sometimes, but not always, this resonance frequency corresponds to the undamped natural frequency, ωo, of the system. This paper explores the responses of analogous mechanical, acoustic, and electrical oscillating systems, comparing the typical measured response curves (displacement, pressure, and current, respectively) used to showcase the concept of resonance for each. Driving point impedance (real, imaginary, magnitude, and phase) is used to compare the three types of systems. Frequency dependence of the input mechanical impedance (measured with an impedance head) for three mechanical systems (damped mass-spring, tuning fork, wineglass) reveals differences depending on where the system is driven. Measurements of the input acoustic impedance (measured with a microflown p-u probe) for a Helmholtz resonator allows for extraction of the undamped natural frequency in the presence of damping which cannot otherwise be ignored. The electrical impedance of series and parallel RLC circuits and a loudspeaker illustrate differences in the definition of “resonance” when compared with analogous mechanical and acoustic systems.
Development of a multi-level predictive soundscape model to assess the soundscapes of public spaces during the COVID-19 lockdowns
Authors: Mitchell Andrew , Oberman Tin , Aletta Francesco , Kang Jian
Published: November 2021

The recent developments in the standardization of soundscape as both a research and engineering field have highlighted the need for models which can predict likely soundscape assessment from objective measurements. Such a need was highlighted during the COVID-19 lockdowns. The unprecedented restrictions in human activity presented a unique opportunity to investigate the urban noise impacts of drastic reductions in traffic noise and human sounds, but simultaneously made it impossible to carry out standard methods of soundscape assessment (i.e., in-person surveys or soundwalks). To address this, a multi-level linear regression model was developed based on an existing database of soundscape surveys and binaural recordings to predict how the soundscapes of 13 locations in London and Venice would have likely been perceived during the lockdowns based on objective measurements. To build this model, a feature selection process was applied to an extended suite of psychoacoustic metrics and a variable characterising the context of each location to identify a minimum set of input features and model structure. This presentation will demonstrate the development of this model, its application in the COVID case study and corresponding results, and will discuss the potential for future applications of a similar predictive soundscape modelling framework.
David Blackstock: Distortion of shock waves and breaking of kidney stones
Authors: Cleveland Robin O.
Published: November 2021

This talk will discuss how the seminal work that David Blackstock carried out in nonlinear acoustics for underwater and atmospheric applications contributed to the understanding of the medical use of shock waves for breaking of kidney stones. David’s expertise lead to him acting as an external advisor for two decades to a NIH funded programme in shock wave lithotripsy; that contribution will be covered elsewhere in the session. I will present the weak shock theory that describes how nonlinear pulses distort when undergoing geometrical spreading. The theory will then be applied to the first clinically approved lithotripter, that employed a spark to generate a shock wave and an ellipsoidal reflector to focus that into the body. Inside the reflector the shock wave undergoes spherical spreading, reflection and then spherical convergence. It will be shown that nonlinear distortion inside the reflector results in variations in phase and amplitude across the mouth of the reflector which then impact the focusing of the shock wave onto a kidney stone. I will reflect on David’s role as a Ph.D. supervisor and his mentorship of acousticians young and old.
Bridging shock: Blackstock’s general solution for propagation of finite-amplitude sound waves
Authors: Foote Kenneth G. , Pierce Allan D. , Hamilton Mark F.
Published: November 2021

Reflections are offered on D. T. Blackstock [“Connection between the Fay and Fubini solutions for plane sound waves of finite amplitude,” J. Acoust. Soc. Am. 39, 1019–1026 (1966)]. This work treats the propagation of planar finite-amplitude sound waves. It nominally links the Fourier-series-based solution of Fubini for the pre-shock condition, and the distant, post-shock solution of Fay. However, addressing the transition region between these two required solving the entire problem, which Blackstock did with aplomb. This additionally enabled specification of undetermined factors in the Fay solution, statement of an explicit bound on the applicability of the solution, and generalization to cylindrical and spherical waves. Hallmarks of Blackstock’s work are evident: scholarly mindfulness of historical precedent, meticulous analysis that inevitably advanced understanding of nonlinear acoustic phenomena, and elegance in presentation, which was, moreover, pedagogically convincing.
David Blackstock and the experimental explanation of the spikes on sonic boom waveforms
Authors: Pierce Allan D.
Published: November 2021

The present paper discusses an extremely clever experiment perforrmed by David Blackstork and his student Bruce Davy at Rochester in the early 1970s. In the late 1960s people were puzzled by some anomalous features in the measured waveforms of sonic booms recorded at the ground during flyovers of supersonic aircraft. The waveforms were supposed to look like the letter N, but that was not always the case. Sometimes there were strange upward reaching spikes just behind the leading and trailing shocks and in other instances the wavefront was rounded. There were a lot of explanations kicking around, and the present author and David Blackstock came up with the idea that it was somehow caused by imperfect focusing of wavefonts after traveling through regions of higher sound velocity. During our discussions, Blackstock came up with the remark, ‘‘Let’s talk experiment.’’ What resulted was an experiment that would have been worthy of Lord Rayleigh. The paper that reported this, titled ‘‘Measurements of the Refraction and Diffraction of a Short N-Wave by a Gas-Filled Soap Bubble,’’appeared in J. Acoust. Soc. Am. in March 1971. Besides really nailing down the physical phenomena responsible for the spikes on sonic boom waveforms, it illustrated a wealth of physical concepts and experimental techniques. The present talk discusses the background of the paper, the physics that it used, and the influence it had on subsequent research.
Remote measurement of spectral weighting in sound localization using virtual reality headsets
Authors: Rejimon Jwala P. , Folkerts Monica L. , Stecker G. Christopher
Published: November 2021

Unequal weighting of binaural information across frequency can reduce sensitivity in the presence of competing but uninformative cues (“binaural interference”), a potentially serious problem for listeners who use combined electric and acoustic (EAS) hearing. Here, we used virtual-reality techniques to measure spectral weighting functions (SWF) during localization of simulated EAS stimuli [see van Ginkel et al., JASA 145, 2445 (2019)]: low-frequency “acoustic” noise bands and high-frequency “electric” click trains. This study was conducted remotely at each participants’ location, using sanitized and calibrated research equipment (Oculus Quest 2 headsets and Sennheiser HD 280 Pro headphones) delivered by lab personnel. Sounds were presented with random binaural-cue jitter across seven components on each trial. SWFs were computed by statistical regression of localization responses onto binaural cue values. SWFs confirmed the dominance of 400–1000 Hz components reported previously [Stecker, Folkerts, & Stecker 2019(A), JASA 145:1720]. Introducing a gap between noise and click-train components increased weight on neighboring components, consistent with reduced interference in such conditions [van Ginkel et al., 2019]. Finally, presenting noises and click trains from competing locations reduced weight on non-target components for most but not all participants, a potential marker of susceptibility to binaural interference. [Work supported by NIH R01-DC016643, NIH T35-008757.]
Migrating in-lab testing to at-home testing: Setup and procedures
Authors: Fan Langchen , Sanders Holden D. , Eddolls Morgan S. , Molis Michelle R. , Reiss Lina A.
Published: November 2021

To reduce the risk of spreading COVID-19, we developed an experimental setup that allows for testing of participants at their home with rigor comparable to the laboratory setting. Testing equipment included a touchscreen laptop, high-quality portable sound card, professional headphones, a hotspot USB for internet connection, and a microphone. All equipment was protected in a custom-molded case. The equipment was dropped off and picked up at the participant’s home before and after the experiment. The experimental programs were coded in Matlab and compiled into Matlab executables. During the experiment, the researcher conducted experiments on the laptop via remote control software. Simultaneous to testing, the researcher gave instructions and monitored the participant through video call. Participants were screened for normal hearing thresholds using a modified audiogram, between 0.25 and 8 kHz, with one-up, one-down procedure. Participants were next tested on dichotic vowel perception. Ambient sound level of the participant’s home was monitored during the experiment. Overall, participants reported that the procedure was easy to understand and follow. Results from remote testing will be compared with those from standard in-person booth testing to validate accuracy of remote testing. [This research was funded by NIH-NIDCD-R01-DC013307.]
Recalling vowel sequences in completing backgrounds: Effects of rhythmic regularity and tempo
Authors: Pearson Dylan V. , Shen Yi , Kidd Gary R. , McAuley J Devin
Published: November 2021

Previous studies have demonstrated that the rhythmic regularities embedded in naturally produced speech are essential for speech understanding in the presence of competing backgrounds. In the current study, the facilitative effect of rhythmic regularity was further investigated using a vowel-recall task. Listeners recalled the last three vowels from a sequence of 9 to 18 synthetic vowels presented at an average rate of 2 vowels/second along with a competing sequence of harmonic complexes. Through this task, the rhythmic regularity (isochronous or anisochronous) and tempo of the target and competitor sequences as well as the duration of exposure to target rhythmic context (i.e., the target sequence length) were independently manipulated without affecting the intelligibility of individual target vowels. Better recall performance was found for isochronous target sequences compared to anisochronous target sequences and with longer exposure to the rhythmic context prior to recall. The rhythmic regularity of the competing signal had no significant effect on recall performance; however, the tempo of the competing signal was significant with recall performance improving as the background tempo increased from 1 to 4 vowels/second. These effects of rhythm and tempo are consistent with theories of selective listening based on attentional entrainment.
Do humans integrate auditory and text information in a statistically optimal fashion?
Authors: Kohlberg Gavriel D. , Prater Eric M. , Shen Yi , Lee Adrian K. C. , Rubinstein Jay T. , Atlas Les E. , Wright Richard A.
Published: November 2021

Decreased speech perception in noise is a major problem, especially for older adults and for those with hearing loss. In order to improve speech perception in noise, the acoustic speech information can be supplemented with visually displayed speech text derived from the output of an automated speech recognition program. While such supplementation of auditory speech information with visual text has been shown to increase speech perception in noise, it is relatively unknown how listeners combine these two modalities of speech information to achieve improved speech perception. We aim to evaluate how listeners combine visual speech text and auditory speech information. We will evaluate subjects’ speech perception based only on auditory information in background noise. We will then evaluate subjects’ speech perception based only on visual text information that is derived from an automated speech recognition system. Using these two assessments of speech perception (auditory alone, visual text alone), we will predict listeners’ combined performance based on a maximum likelihood estimate model. We hypothesize that listener’s performance on joint presentation of auditory speech information with visual text information can be predicted based on the listener’s performance on separate presentations of auditory speech information alone and visual text information alone.
Differences in sound-source localization in reverberant environments that depend on stimulus-type and mode of presentation
Authors: Pastore M. Torben , Zhou Yi , Braasch Jonas , Yost William A.
Published: November 2021

One interesting aspect of sound-source localization in reverberant environments is that different stimuli (e.g., speech versus noise) can elicit different spatial sensations at the same delays between the direct sound and its reflections. For example, a given delay between a single simulated direct sound and a delayed copy presented from a different location may elicit the sensation of either a single sound located at or near its source for speech while a noise stimulus under otherwise the same conditions might be perceived as a direct sound with echoes. Furthermore, presenting stimuli over headphones versus loudspeakers can further modify spatial perception for the same stimulus conditions. This modeling study will explore reasons for these two interesting differences of behavioral outcome, using simulation tools developed in Montagne and Zhou (JASA, 2018) and Pastore and Braasch (JASA, 2020).
Prediction of speech recognition in background noise and competing speech from suprathreshold auditory and cognitive measures
Authors: Venezia Jonathan H. , Whittle Nicole , Herrera Ortiz Christian , Leek Marjorie R. , Barcenas Caleb , Lee Grace
Published: November 2021

Previous studies have struggled to identify measures beyond the audiogram to reliably predict speech-in-noise scores. This may owe to: (i) different mechanisms mediate performance depending on materials and task; and (ii) effects are not reproducible. Here, 38 listeners with normal/near-normal audiograms completed batteries of temporal auditory and cognitive tests, and speech recognition (“Theo-Victor-Michael” test) in speech-shaped noise (SSN), speech-envelope modulated noise (envSSN), one (1T) and two (2T) competing talkers. A two-stage Bayesian modeling approach was employed. In Stage 1, speech scores were corrected for target-word frequency/neighborhood density, psychometric function parameters were extracted from temporal tests, and cognitive measures were reduced to three composite variables. Stage 2 then applied Gaussian process models to predict speech scores from temporal and cognitive measures. Leave-one-out cross-validation and model stacking determined the best combination of predictive models. Performance in SSN/envSSN was best predicted by temporal envelope measures (forward masking, gap duration discrimination), while performance in 1T was best predicted by cognitive measures (executive function, processing speed). Temporal fine structure measures (frequency-modulation, interaural-phase-difference detection) predicted the number of 1T distractor responses. All models failed on 2T. These results show that prediction of speech-in-noise scores from suprathreshold “process” measures is highly task dependent.