bluuebunny/crossref_metadata_2025 huggingface dataset:
Manufacturing and uniformity of grain textured piezoelectric ceramics
Authors: Fanton Mark , Watson Beecher , Meyer Richard J. , Eadie Christopher
Published: June 2021

Directional tailoring of performance for ceramic materials has been largely limited to taking advantage of anisotropies in single crystal or composite materials. This presentation outlines the process technology and scale up considerations for tailoring directionally oriented ceramic microstructures, with a focus on achieving near single crystal performance from highly oriented ceramic piezoelectric materials in the PIN-PMN-PT, and PMN-PZT families of materials. The engineering challenges associated with scaling each step of the manufacturing process for both tape cast approaches and additive manufacturing approaches will be outlined as will observations regarding process variability. In addition, we will discuss modifications to these textured compositions and processes to control performance characteristics such as loss factor and coercive field. The electro-mechanical performance and performance trade-offs of materials for acoustic applications will be discussed.
Evaluating the impact of acoustic impedance matching on the airborne noise rejection and sensitivity of an electrostatic transducer
Authors: Rennoll Valerie , McLane Ian M. , Eisape Adebayo , Elhilali Mounya , West James
Published: June 2021

To capture sound from solid mediums, such as the human body or musical instruments, transducers designed for airborne sound pickup are typically used. Acoustic impedance mismatches between the medium and transducer decrease the energy captured and increase noise corruption. Here, we demonstrate the improved sensitivity and airborne noise rejection of an electrostatic transducer with an acoustic impedance matched to the medium of interest. The transducer produces an electrical response when mechanical vibrations compress the distance between an elastomer with patterned microstructures and a charged electret film. Using a statistical model generated through an I-optimal design of experiments, the elastomer is fabricated with a specific polymer and concentration of nanoparticles to possess a targeted acoustic impedance. Transducers containing elastomers with impedances in the range of 1 to 2.2 MRayls are assembled and characterized on simulators emulating the human body and a wooden instrument. The noise rejection is quantified using the coherence between the captured transducer signal and the simulated ambient noise. Sensitivities are similarly characterized by comparing the transducer signal and input simulator signal. With an impedance closely matched to the medium of interest, the transducer demonstrates a 2V/N sensitivity and 35 dB SNR improvement compared to an airborne transducer.
Reverse-engineering a digital twin of a classical guitar using the finite element method and experimental modal analysis
Authors: Brauchler Alexander , Ziegler Pascal , Eberhard Peter
Published: June 2021

The classical guitar is not only delighting musicians and audiences worldwide but also scientists are interested in the interplay of the coupled oscillatory systems that constitute the instrument. The bridge couples the plucked strings with the guitar body, which acts as an amplifier to radiate the guitar's sound while being, additionally, coupled strongly with the enclosed air volume. In this contribution, a numerical finite element model of a classical guitar body is presented and compared to experimental data. The guitar's geometry is reverse-engineered from computed tomography scans to a very high level of detail, and care is taken for including all necessary physical influences. Five different sorts of wood used in the guitar are modeled with their corresponding orthotropic material properties, and the fluid–structure interaction between the guitar body and the enclosed air is taken into account in the coupled finite element model. To substantiate the quality of the numerical model, the numerically calculated modal parameters are compared to experimentally identified ones. For this reason, an experimental modal analysis setup employing a scanning laser Doppler vibrometer is proposed, and modal parameters are identified utilizing the complex mode indicator function and enhanced frequency response functions.
Numerical and experimental assessment of string gauge influence on guitar tone
Authors: Bielski Pawel M. , Mikulski Tomasz , Pruszko Hanna
Published: June 2021

String gauge is known for affecting a guitar's tone, playability and volume. It is often a subject of debate between younger players and becomes a staple and signature of older ones. The choice between the heavier or lighter strings is usually made based on personal taste and practical reasons. Although string gauge is intuitively associated with fatter or thinner sound, physics behind string vibration do not necessarily confirm this assumption. In the study, the impact of string gauge on the guitar's tone is assessed in several ways. A numerical study is carried out, introducing a time-domain dynamic analysis of a coupled string-structure system. A basic experimental study is also performed to validate the numerical results. The study is focused on estimation of the three aspects of sound—harmonic composition, sustain and volume—and how they are affected by the guitar's string gauge.
Noise and air pollution during lockdown around a school site in the UK
Authors: Kumar Prashant , Omidvarborna Hamid , Kooloth Valappil Abhijith , Bristow Abigail
Published: June 2021

Noise and air pollutants share many common sources including traffic volume. Noise pollution causes annoyance and disturbs sleep and it is the second risk factor, after air pollution, to the estimated environmental burden of disease in Europe. It can also act as a proxy for some of the air pollutants, to allow building of holistic view of environmental pollution. During the pandemic and the resulting lockdowns in cities across the world, traffic volumes reduced significantly, leading to reduced pollutant concentrations and noise levels. In this work, we present an analysis of the multiple pollutants (e.g., fine particulate matter, nitrogen oxide) and noise data that are monitored continuously during the lockdown at 15-minute resolution at a school site in the UK, which is situated next to a busy road. This talk will present trends of noise and the air pollutants during the lockdown period, explore possible relationship of noise as a proxy for air pollutants; variations between pollutants and the underlining reasons explaining the temporal variations. [This work is supported by Guildford Living Lab and INHALE (EP/T003189/1). We thank the Sandfields Primary school, its governors and the parent group for supporting this work.]
Contrast agent microbubble scattering in response to sub-resonant ultrasonic driving
Authors: Prentice Paul
Published: June 2021

Much of the literature describing contrast agent microbubble response to ultrasound, details exposure to frequencies of 1 MHz, or above. The application of microbubble-mediated and transcranial focused ultrasound therapy of the brain, however, is clinically administered at 220 kHz to achieve adequate transmission across the skull. This excitation frequency is an order of magnitude below accepted values for microbubble resonances, yet fundamental studies of such sub-resonantly driven microbubble activity have only recently started to emerge. In this presentation our recent high-speed imaging-based investigations of single and multiple clinically approved microbubbles, exposed to sub-MHz focused ultrasound, will be reviewed. The observations indicate that the well documented microbubble response to higher frequencies, may not be applicable to lower frequency therapeutic driving. Specifically, periodic bubble-collapse generated pressure impulses are shown to account for all non-linear scattering, including subharmonics, harmonics and broadband noise, dependent on the amplitude of the driving [Song et al., in UMB (2019)]. A new mechanism for microbubble-jetting, which occurs spontaneously on interaction between the microbubble at first inflation, and the pressure gradients within the initial cycles of a burst of sub-MHz focused ultrasound, will also be described [Cleve et al., in UMB (2019)].
A statistics-based model for cavitating polydisperse bubble clouds and their two-way-flow coupling
Authors: Bryngelson Spencer H. , Colonius Tim
Published: June 2021

Phase-averaged bubbly flow models require statistical moments of the evolving bubble dynamics distributions. Under step forcing, these moments reach a statistical equilibrium in finite time. However, actual flows entail time-dependent pressure forcing and equilibrium is generally not reached. In such cases, the statistics of the evolving bubble population must be represented and evolved. Since phase-averaged models compute these moments point-wise, a low-cost algorithm for this evolution is of particular significance for large-scale simulations. We present a population-balance-based method for this purpose. The bubble dynamic coordinates are treated via a quadrature moment method and conditioned on the equilibrium bubble size. Statistics in the equilibrium bubble size coordinate are computed using a fixed quadrature rule and averaged over the period of bubble oscillation. Results show that two quadrature points in each of the bubble dynamic coordinates are sufficient to quantitatively reproduce key statistics. Further, averaging is shown to remove oscillatory behaviors that do not contribute to the moments. Together, this results in a method capable of tracking the bubble population statistics with significantly less computational expense than Monte Carlo approaches. The generality introduced by including statistics in the bubble dynamics coordinates is explored via acoustically excited bubble screen problems.
The McGurk illusion
Authors: Van Engen Kristin J.
Published: June 2021

In 1976, Harry McGurk and John MacDonald published their now-famous article, “Hearing Lips and Seeing Voices.” The study was a remarkable demonstration of visual influence on auditory speech perception: when an auditory stimulus (e.g., /ba/) was presented with the face of a talker articulating a different syllable (e.g., /ga/), listeners experienced an illusory percept distinct from both sources (e.g., /da/). In the subsequent 45 years, this effect has been used in countless studies of audiovisual processing in humans. It is typically assumed that people who are more susceptible to the illusion are better audiovisual integrators. However, when it comes to understanding multisensory speech perception, there are several reasons to argue that McGurk stimuli are poorly suited to the task. Most problematic is the fact that McGurk stimuli rely on audiovisual incongruence that never occurs in real-life audiovisual speech perception. Furthermore, recent studies show that susceptibility to the effect does not correlate with performance during audiovisual speech perception tasks. This presentation will review these issues, arguing that, while the McGurk effect is a fascinating illusion, it is the wrong tool for understanding the combined use of auditory and visual information during speech perception.
A critical look at commonly used stimuli in speech perception experiments
Authors: Winn Matthew , Wright Richard A.
Published: June 2021

Speech is an attractive stimulus to use for testing the auditory system because it is both highly relevant to everyday life and also replete with acoustic complexity that can test a variety of auditory skills. This presentation shines a light on some commonly used test stimuli or stimulus practices and raises questions about their use, or the interpretations of previous results. For example, the vowel acoustic data published by Hillenbrand et al. (1995) has been adopted as a de facto gold standard even though it was intended as a snapshot of a single dialect at a particular point in time. In that paper, the dynamics of vowel spectra were emphasized, though this aspect of vowels has been often overlooked. In consonant testing, the use of the /a/ context is pervasive, and yet this consonant environment is far from “neutral,” especially in situations where perception of voicing/voice onset time is measured. Perception of consonants and words will be examined with regard to their generalization to perception of longer utterances. Finally, we will examine the balance between convenience and generalizability, including strengths and weaknesses of closed-set speech stimuli.
Words matter: Analyzing lexical effects on recognition and effort using normed word stimuli
Authors: Kuchinsky Stefanie E. , Razeghi Niki , Pandza Nick B.
Published: June 2021

Clinical assessments of speech-perception difficulties involve speech-in-noise tests in which individuals recognize words (or sentences) at varying signal-to-noise ratios (SNRs). Words are presented in lists that have been balanced based on their phonetic properties or on their average intelligibility in quiet from norming studies. Such list-wise balancing presumably allows for generalizations to be drawn about the difficulty of an SNR irrespective of word-level difficulty. However, differences in the lexical properties of items (e.g., lexical frequency) may yield substantial variability in how hard individuals work to recognize each word, especially in poorer SNRs. To demonstrate the impact of word-level factors on assessments of listening difficulty, I will present the results of a study with 26 younger, normal-hearing adults. Participants recognized 160 monosyllabic words in noise from the Northwestern University Auditory Test Number Six (NU-6) in acoustically and cognitively demanding conditions. Multilevel models simultaneously assessed word-level (lexical frequency) and participant-level effects on a dual-task measure of listening effort. Results revealed interactions among acoustic, lexical, and cognitive demands on effort, even for items that were correctly identified. These findings highlight the importance of considering item-level difficulty on speech recognition tests even when using normed speech materials. [This work is supported by NIH/NIDCD R03DC015059.]
Is speech perception what speech perception tests test?
Authors: Beechey Timothy
Published: June 2021

Speech signals employed in clinical and research contexts are thought to be realistic or representative to the extent that they consist of phonetic, lexical, and morphosyntactic content. These characteristics may be assumed to ensure that speech perception tests are representative of the demands of real-world speech perception and understanding, and therefore that these tests are predictive of real-world speech understanding. However, there are numerous reports of discrepancies between the results of speech perception tests and real-world speech understanding and hearing device benefit. To make optimal use of existing speech tests, and to design more predictive speech tests in the future, it is important to consider how clinical and research speech tests do and do not represent the process and demands of everyday speech understanding. Speech and language examples from a single talker engaged in conversation with a hearing-impaired interlocutor in a range of realistic acoustic environments will be contrasted with widely used recordings of BKB sentences produced by the same talker. The absence of much natural variation in standard speech test materials, as well as a failure to quantify perception of information which cannot be captured orthographically, will be discussed as limitations to the generalizability of standard speech test results.
Reconsidering variability in child speech production
Authors: Cychosz Margaret
Published: June 2021

Child speech is highly variable between and within speakers. This pattern has traditionally been explained by a lack of motor routine and articulatory control in the developing speech-motor apparatus. But the assumption that child speech is inherently variable—and the result of motor development and control—may be premature. Recent work suggests that some child speech variation may instead be attributable to errors in measurement: children's high fundamental frequencies make many traditional acoustic measures, such as formant tracking, unreliable and variable. Additionally, child speech variation can often be explained by experiential factors, such as the size of the lexicon or the type and quantity of language exposure. This talk will report on these and other recent findings that suggest a need to reconsider the prevalence of, and reasons for, variability in young children's speech.
Passive acoustic detection and tracking of an unmanned underwater vehicle from motor noise
Authors: Railey Kristen , Dibiaso Dino , Schmidt Henrik
Published: June 2021

Using passive acoustics to distinguish unmanned underwater vehicles from other marine traffic in a complex environment and tracking a vehicle to understand its intent is critical for harbor security. Ships and boats can be classified by their unique acoustic signature due to machinery vibration and detection of envelope modulation on (cavitation) noise. However, cavitation noise of unmanned underwater vehicles is quieter than these vessels, and bearing-only measurements using a stationary array are insufficient for tracking. Tracking accuracy depends on the quality of acoustic measurements, such as high SNR, and observability, estimating vehicle state from the data available. In this work, we demonstrate that it is possible to passively track a vehicle from high-frequency motor noise using a stationary array in a shallow water experiment with passing boats. Motor noise provides high SNR measurements of bearing, bearing rate, propeller rotation, and range rate that are combined in an Unscented Kalman Filter to track the vehicle. First, receiver operating characteristic curves are generated to evaluate detection and false alarms. Conventional beamforming is applied to estimate bearing and bearing rate. Range rate is calculated from the Doppler effect of the motor noise. Propeller rotation is estimated from sideband spacings in the motor signature. [Work supported by Draper, ONR, and DARPA.]
Acoustic fields of unmanned aerial vehicles in the tasks of passive detection
Authors: Gravirov Valentin V. , Zhostkov Ruslan A. , Presnov Dmitriy A.
Published: June 2021

The increasingly widespread use of unmanned aerial vehicles (UAVs) requires improved methods of their detection. In some cases, this is only possible by analyzing the physical fields created by the UAV. This work is dedicated to the study of the UAV’s acoustic field as applied to the problem of passive detection. In the laboratory, the acoustic fields of the most popular quadcopters were studied, as well as the properties of individual propellers of various designs. The influence of blade defects on the resulting spectral portrait was analyzed. Based on the results of numerical simulations in the COMSOL Multiphysics software package, directional patterns and pressure variations caused by a rotating propeller are obtained. A neural network has been trained to analyze the kepstrum coefficients calculated from acoustic records. The neural network allows monitoring and recognizing the presence of a quadrocopter in an area of interest, taking into account natural and anthropogenic noises. Field experiments carried out in urban conditions made it possible to estimate the range of possible passive detection of an unmanned aerial vehicle. [This work was financially supported by the Russian Foundation for Basic Research (Project No. 19-29-06062).]
Explainable artificial intelligence: Linking domain knowledge and machine interpretation using cognitive sampling of acoustical datasets
Authors: Gupta Ananya Sen , Kubicek Bernice , McCarthy Ryan A. , Linhardt Timothy , Hermann Luke , Kemerling Madison
Published: June 2021

Explainable artificial intelligence is gaining wider traction within the machine learning community and its application domains at large for its inherent motivation to explain and interpret large-scale machine interpretation of experimental datasets. We will present cognitive sampling as new way to implement explainable AI for acoustical signal processing. In particular, methods based on geometric signal processing and sparse sensing will be harnessed with machine cognition to interpret, classify and predict information autonomously from large-scale acoustic datasets spanning a wide variety of applications. We will compare the difference in performance between traditional supervised and semi-supervised learning architectures such as deep learning, and ensemble approaches, unsupervised learning networks. We will also present preliminary research on implementing cognitive sampling in machine-directed inverse problem-solving techniques such as autoencoders. The end goal is to discover efficient data encodings that enable hitherto unforeseen feature spaces using optimal or close to optimal sampling strategies. Specific applications will include a variety of acoustical environmental sensing applications involving spectral feature generation and interpretation such as sonar signal processing, undersea multipath channel sensing, as well as feature extraction in complex melodic structures in Indian classical music. [Work funded partially by ONR under Grants N00014-19-1-2436, N00014-19-1-2609, N00174-20-1-0016 and N00014-20-1-2626.]
Autonomous towed hydrophone system detects many beaked whales and other cetacean species in waters of the Southern Ocean
Authors: Barlow Jay , Cheeseman Ted , Trickey Jenny S.
Published: June 2021

A SoundTrap ST300HF hydrophone recorder in a streamlined, flooded towbody was towed behind expeditionary tourism vessels on trips to South Georgia and the South Sandwich Islands and to the Antarctic Peninsula in December 2019—February 2020. Recordings were analyzed to identify acoustic detections of cetacean species. Identified species included sperm whales (Physeter macrocephalus) and southern bottlenose whales (Hyperoodon planifrons). Acoustic detections also included echolocation pulses from several previously described beaked whale pulse types (BW37 and BW58) as well as a possibly new type of beaked whale echolocation pulse. Narrow-band high-frequency (NBHF) echolocation signals (typical of porpoises and some dolphin species) were detected at several locations, and one of these coincided with a sighting of hourglass dolphins (Lagenorhynchus cruciger). Unidentified large delphinids were also detected several times. This study shows the utility of a simple towed hydrophone system on a vessel of opportunity to study the distribution of cetaceans in rough seas that are difficult to study by visual survey methods. Additional research is needed to link the unidentified echolocation signals to known species throughout waters of the Southern Ocean.
The development and use of towed hydrophone arrays to inform Southern Resident killer whale Critical Habitat in outer coastal waters
Authors: Hanson M. Bradley , Holt Marla M. , Emmons Candice , Noren Dawn P. , Ferguson Elizabeth L. , Coates Shannon , Dunleavy Kerry , Hom-Weaver Corry , Jacobsen Jeff
Published: June 2021

Southern Resident killer whales (SRKW) were listed as endangered in 2005, requiring designation of Critical Habitat. At that time little was known about SRKW distribution in winter/spring along the outer coast. From 2004 to 2016, we conducted nine winter/spring surveys aboard NOAA ocean-class vessels to locate and follow SRKW pods using visual sightings, satellite telemetry, and passive acoustic monitoring using towed hydrophone arrays. We present information on the evolution of the towed hydrophone array system, and insights gained on the movements and acoustic behavior of this population. Beginning with a linear two-element hydrophone array system, operations evolved to include a secondary, five-element array towed in parallel, to resolve left-right bearing ambiguity to vocalizing animals. Acoustic localization allowed tracking of vocalizing whales when visual surveys were not possible (e.g., nighttime/inclement weather). When visual and/or satellite tag position data indicated whales were within acoustic range, vocalizations were detected only 45% of the time, a result that has implications for other PAM efforts. These surveys helped fill important gaps in our understanding of SRKW occurrence to inform Critical Habitat in the outer coastal portion of their range. Despite limited monitoring, we established the importance of this key portion of their range in winter/spring.
Automated regularization parameters method for the inverse problem in ultrasound tomography
Authors: Carević Anita , Slapničar Ivan , Almekkawy Mohamed
Published: June 2021

Ultrasound tomography (UT) is an emerging technology that has been applied for the detection of breast cancer. It is safe and cost effective medical imaging modality that can provide a high-quality image and is free from patient constraint of magnetic resonance imaging (MRI) and computed tomography (CT). One of the methods to solve the problem of UT is to model it as an integral form and apply the distorted Born iterative method. This method needs a regularization parameter in each iteration to solve the inverse problem. We developed a new algorithm to automatically choose the regularization parameters needed by balancing the signal loss and the scaled noise error. We applied our new algorithm with Tikhonov regularization in general form to regularize the inverse problem to reconstruct a simulated breast phantom image. The performance of our algorithm is compared to those of L-curve, GCV and the projection based total least squares methods. Our proposed algorithm provides the highest reconstructed image quality with the lowest relative error in all tested cases with different frequencies and noise levels.
Ceramic additive manufacturing for enhanced piezocomposite transducers
Authors: Tufariello Justin , Allan Shawn , Robinson Barry , Pazol Brian , Riesenhuber Leslie , Angilella Alex , Corrado Casey
Published: June 2021

Ceramic Additive Manufacturing (AM) offers the potential to create piezocomposite structures with refined and customizable features that result in augmented performance for underwater acoustic transduction. Novel geometries that would otherwise be impossible to fabricate with conventional manufacturing methods may be efficiently created through AM processes to invoke increased sensitivity and improved directionality. These favorable characteristics promise enhanced sensing performance on compact and autonomous Navy platforms where efficiency is critical and spatial aperture may be limited. To date, Lithoz-America, LLC (Lithoz), The MITRE Corporation (MITRE), and MSI Transducers Corp. (MSI) have entered a Collaborative Research Agreement that has been successful in utilizing Lithoz’s patented lithography-based ceramic manufacturing (LCM) process to create innovative PZT-5H (DoD Type VI) structures. MSI has applied broad material knowledge to create ceramic powders for slurry creation and refine post-processing procedures for repeatable sintered material properties equivalent to bulk ceramic. Through the process, an AM 1-3 piezocomposite transducer, resonant at 71 kHz, was compared against a replica conventionally manufactured transducer with excellent measured acoustic response agreement. MITRE has utilized coupled-acoustic finite element analysis (FEA) to design and evaluate distributed composite apertures and auxetic structures with improved performance and only feasible to manufacture with AM.
Thermoacoustic Instability in the flexural motion of a bilayer beam
Authors: Hao Haitian , Scalo Carlo , Semperlotti Fabio
Published: June 2021

Recent studies have shown that axial waves in a one-dimensional solid rod can become thermoacoustically unstable in presence of a spatial temperature gradient [Hao et al., J. Appl. Phys.123(2), 024903 (2018)]. It is well-known that elastic waves in solids can occur in a variety of mode types dominated by different displacement profiles. This study presents the theory of flexural-mode solid-state thermoacoustics (F-SSTAs) according to which flexural waves in a bilayer slender beam subject to a spatial thermal gradient can become thermoacoustically unstable. The instability in F-SSTA was linked to three factors: (1) the asymmetric distribution of the temperature fluctuation in the cross-section, (2) the non-uniform thermal moment in the axial direction, and (3) the spatial thermal gradient. The criterion for the occurrence of flexural instability in bilayer beams was identified by exploring both the mechanics and the thermodynamics of the system. The existence of a thermally induced unstable response was further substantiated by direct numerical simulations. Finally, although the experimental investigation was not able to achieve a fully sustained instability, data showed clear evidence of thermal-to-mechanical energy conversion in the F-SSTA process.
Supporting hyflex acoustics laboratory exercises
Authors: Hawley Scott H.
Published: June 2021

Challenges for laboratory instruction due to COVID include lab room occupancy being cut in half, the prohibition of lab partner arrangements, and students (or instructors) who, on any given day, might be unable to attend lab in person. To allow students to perform laboratory exercises at home requires accounting for a heterogeneous set of available equipment (typically of low-precision) and a multiplicity of computing platforms. The author's Mac-only software suite “SHAART Acoustic Tools” needed porting to Windows and Linux executables so students could measure reverberation times at home. In this talk, we share some experiments, apps, and cross-platform tricks that enabled students to have a reasonably uniform experience that was also manageable for the instructor.
The past, the present, and the future of acoustics in Hong Kong
Authors: YEUNG Maurice
Published: June 2021

Accommodating over 7 million population in about 1100 km2 area, Hong Kong is truly a densely populated city. Also, with its almost 24-hour non-stop activities, Hong Kong is a vibrant and dynamic city. These two factors undoubtedly put environmental noise like traffic noise and neighborhood noise center of public concerns. Hence, combating environmental noise became the top priority in the development of acoustics in Hong Kong. With further developing into an international finance center in which luxurious hotels plus sophistically designed performance centers were planned and built, excellent knowledge and experience of indoor acoustics and architectural acoustics became mostly needed. These spectacular demands set path for collaborations for local and overseas acoustic researchers, academia and professionals in spearheading initiatives like a noise-heath study associated with over 10,000 household surveys; the world first ever three-dimensional traffic noise mapping; the largest theatre for Xiqu (the Chinese traditional opera) and currently the largest number of residential developments applying open-typed windows for noise amelioration. This paper gives a summary of the developments of acoustics in Hong Kong, reviews its current status and portrays its future including the discussion of how the acoustical professionals and academics in Hong Kong would benefit from international collaborations and educations in acoustics in the years to come.
Creation of acoustic environment from the viewpoint of perception and cognition
Authors: Akita Takeshi
Published: June 2021

The investigations of our research team are generally carried out for the purpose of creating good acoustic environment from the perspective of person's perception and cognition. The concept of the researches is supported by the framework of soundscape that is defined in ISO 12913-1. It shows that soundscape that is perceived by a person is affected by the context that is different among individuals. Among the context that is illustrated by many examples in ISO, the background systems of perception and cognition like attention to the acoustic environment, forepast experience of soundscape, person’s sense of value, and effects of vision on perception of soundscape are mainly paid attention to in our researches. In contrast, there are little researches about perception and cognition of sonic environment or evaluation of it that is associated with ISO 12913-1 in Japan. It seems that such situation makes it difficult to discuss about good acoustic environment consistently. In the future, it is considered as an important way to try to create good acoustic environment involving the viewpoint of the context that has significant effect on perception and cognition not only in our country but also worldwide.
COVID-19 and self-reported noise reports: A comparative study
Authors: Yildirim Yalcin
Published: June 2021

COVID-19 has affected people's lives differently, from mobility concerns and staying-at-home orders to all life routines. These changes have, in turn, affected daily life in urban environments based on different factors, including air quality and noise. For example, COVID-19 has resulted in quieter environments due to less mobility on streets and less anthropogenic activities. On the other hand, staying-at-home orders promote more activities to occur at the building scale, i.e., individual stay at home and produce more noise for neighbors. This study examines the noise complaints data in Dallas, USA, to understand this association by comparing the noise complaints during the COVID-19 period and the same data period in 2019. Findings surprisingly show reduced noise complaints during the COVID-19 time frame by about 14% compared to the pre-COVID-19 period. The study then performed spatial and statistical analyses, and findings show that the majority of noise reduction occurred in the city center. In other words, the noise complaints were more spatially dispersed at the outskirts of the city during the COVID-19 period. To identify specific factors, there is a need for some other techniques and studies.
Noise complaints in New York City and their relationship with housing cost—Before and after COVID
Authors: Schiff Martin
Published: June 2021

This work explores how escalating New York City rent and noise dissatisfaction may interrelate, and whether pre-pandemic trends held up during 2020 and beyond. Are there parts of town that combine affordable rent and low noise complaint rates? Can past complaints and housing trends predict when and where noise complaints are most likely, and does this hold up in a city on lockdown? Using eleven years of New York City “311” hotline noise complaint records (over three million individual complaints) and combining these with neighborhood rent statistics, comparisons can be made on a local level. A positive correlation is apparent between monthly median rent and monthly noise complaint rate in every borough and sub-district in the city. Whether this is causal or inflationary coincidence is uncertain, and massively increased complaint rates during lockdown defy past trends.
Noise annoyance in dwellings during the first wave of Covid-19
Authors: Sentop Dümen Ayca , Saher Konca
Published: June 2021

In March 2020, strict lock-down measures were imposed in response to COVID-19 pandemic. These restrictions greatly affected our lives together with our environment. While indoor activities increased, streets got tranquil. On Noise Awareness Day 2020, Turkish Acoustical Society started an online survey on noise annoyance in dwellings. 1053 People responded questions on perceived noisiness, dwelling satisfaction, and noise annoyance for two time periods: (1) before and (2) during the pandemic. Stress and anxiety at the time was also evaluated. The results showed that traffic noise annoyance decreased while annoyance due to own-dwelling noises increased. Although being higher than both, neighbor noise annoyance did not change significantly. People who perceived their environment as “noisy” were more satisfied with their dwelling during COVID-19, and those who perceived as “quiet” were less satisfied. Noise sensitivity and annoyance were positively correlated with stress and anxiety while individual changes in annoyance (Aduring–Abefore) were independent. Finally, environmental noise levels (1) before COVID-19, (2) during total lock-down and (3) partial lock-down were measured at two locations. During total lock-down noise levels dropped 7.8dB near a main road while it increased 5 dB near greenery due to human activities. During partial lock-down the levels dropped 2.4 dB and 2.1 dB respectively.
Articulatory and acoustic phonetics of voice actors
Authors: Feehan Colette
Published: June 2021

Looking at voice actors' novel productions of typical speech sounds can tell us more about over which muscles we have volitional control. This can help us to test models of speech production, inform speech therapy, and create better pedagogy for teaching vocal performance.
Correlation signal processing for determination of the spatial distributions of temperature and acoustic characteristics of the medium
Authors: Dmitriev Konstantin , Rumyantseva Olga , Yurchenko Sergey A.
Published: June 2021

It is required in some applications to determine spatial temperature distribution inside investigated object, when direct measurement is impossible, and IR and microwave methods do not provide acceptable spatial resolution. For example, such problems arise in diagnostics of soft biological tissues lying at a depth of about 10 cm or more, and in hyperthermia. To do this, thermal acoustic radiation of the object can be used, which is similar to thermal electromagnetic radiation. It is required to solve the complicated inverse radiation-scattering problem. The intensiometric approach allows determining temperature by signal power measuring at each receiver and by subsequent processing. The correlation processing approach involves calculating the cross correlation functions for each pair of receivers. This approach improves the resolution. The acoustic field focusing is used to further improve the sensitivity and resolution. Moreover, the receiver system can be supplemented with transmitters creating a controlled noise field that is similar to the thermal acoustic field of the object. In this case, the algorithm is proposed that uses three data sets obtained under different experimental conditions. This algorithm allows to separately reconstruct the spatial distributions of temperature, absorption coefficient, and sound speed. [This study was supported by RFBR under Grant No. 21-32-70003]
Web-based visualization of long-term ocean acoustic observations and modelled soundscapes
Authors: Butkiewicz Thomas , Ware Colin , Miksis-Olds Jennifer , Lyons Anthony P. , Atkin Ilya
Published: June 2021

The Atlantic Deepwater Ecosystem Observatory Network (ADEON) is an array of hydrophones deployed along the U.S. Mid- and South Atlantic Outer Continental Shelf, that has been collecting long-term measurements of natural and human sounds in the region since 2017. This presentation focuses on the design and implementation of a web-based geospatial visualization interface that allows anyone to easily explore the massive datasets being generated in order to gain insight about the ecology and soundscape of the region. Visitors to the public website can use an interactive map of the ADEON project region to see the locations of the hydrophone deployments, 2D overlays of contextual data such as sea surface temperature and chlorophyll levels, and 3D modelled soundscapes. Selecting individual deployment stations brings up visualization interfaces that provide multiple ways to explore the data that has been collected there. A perceptually optimized tri-level spectrogram viewer permits rapid exploration of multiple years of raw recordings, and a similar deviations viewer reveals times when the ocean was unusually loud (or quiet) at various frequencies. An interactive heat map visualization presents the results of marine mammal detection algorithms, providing insight into migration behaviors, relationships with surrounding conditions such as temperature and chlorophyll, and cyclical patterns.
Arterial stiffness estimation with shear wave elastography
Authors: Roy Tuhin
Published: June 2021

In arterial shear wave elastography, the arterial wall is excited with acoustic radiation force and the resulting wave propagation through the arterial wall is analyzed to estimate the wall modulus. In this talk, we present a guided wave inversion framework not only to estimate elastic modulus but also the viscoelasticity, which is often considered an important additional biomarker.
Ultrasound measurement of transmural fiber orientation and 3D tissue strain in excised myocardium under uniaxial loading
Authors: Cormack John M
Published: June 2021

The noninvasive measurement with ultrasound of myofiber orientation and 3D tissue strain through the tissue thickness during the application of uniaxial tension is demonstrated on porcine myocardium. Complex tissue deformation, including rotation of myofiber sheets, during the application of stretch is observed.
Acoustic emissions from echocontrast agents infused through an EkoSonic endovascular system in vitro
Authors: Kennedy Sonya , Lafond Maxime , Haworth Kevin J. , Huang Shao-Ling , Peng Tao , McPherson David D. , Genstler Curtis , Holland Christy K.
Published: June 2021

The objective of this study was to explore the location and amount of cavitation nucleation from Definity® or drug-loaded echogenic liposomes infused through the EkoSonic endovascular system (Boston Scientific, Arden Hills, MN) in an in vitro model mimicking porcine femoral arterial flow. Passive cavitation images were acquired during echocontrast agent infusion and 2.2 MHz EkoSonic ultrasound exposure over a range of ultrasound drive powers (4 W-47 W), and the ultraharmonic and inharmonic energy patterns were compared.
The use of (bi-)normal modal expansions for modeling sound propagation in the atmosphere
Authors: Waxler Roger M.
Published: June 2021

One method for solving the equations of sound propagation in the atmosphere is to expand the propagating acoustic pressure with respect to the eigenfunctions (or modes) of the vertical part of the equations in the frequency domain. In the approximation that the atmosphere is vertically stratified, using an expansion in vertical modes is an implementation of seperation of variables. In the simplest case, the propagation is described by a wave equation with the sound speed depending on altitude. Finding the vertical modes requires that one solve the eigenvalue problem for the resulting vertical operator. When attenuation is included, this operator is not self-adjoint, increasing the complexity of the problem and leading to modes which are not orthogonal, but rather bi-orthogonal: that is, orthogonal to the corresponding modes of the adjoint operator. The use of and methods for obtaining modal expansions for sound propagation in the atmosphere will be discussed, ranging from low frequency audible sound propagating in the nocturnal boundary layer to infrasound propagating in the global atmosphere. If the number of modes required is small, the modes provide a compelling physical picture complimentary to that provided by geometrical acoustics.
A mode based broadband scattering model for deep water sound propagation
Authors: Periyasamy Sivaselvi , Chandrayadula Tarun K , Colosi John A. , Worcester Peter F. , Dzieciuch Matthew A.
Published: June 2021

Internal-wave induced sound-speed perturbations cause phase and intensity fluctuations of time-fronts. This paper focuses on predictions for broadband Transmission Losses (TL), time wander, and Scintillation Index (SI), along various sections of a typical deep water time-front. These statistics are usually predicted using Monte-Carlo Parabolic Equation (PE) simulations, or the high frequency based path-integral method. A physics based model that fully connects the wave-field statistics, and the internal wave spectrum, to the broadband statistics is not yet available. This paper uses the mode-based transport theory approach to predict the pressure field scattering at different frequencies, and from that the broadband statistics. This requires calculations for cross-modal correlations over mode number and frequency, which becomes computationally intensive for large bandwidths. This paper considers the adiabatic phase coherence to simplify the computations, and tests the final predictions against PE simulations and observations from the Philippine Sea 2010 experiment.
Separation of acoustic normal modes in shallow water
Authors: Sergeev Sergei , Dmitriev Konstantin , Shurup Andrey
Published: June 2021

The normal mode method is widely used for the acoustic field presentation in the deep ocean. In shallow water, the advantages of the mode description are not obvious, since in this case the mode structure is determined by the boundary conditions at the bottom and the surface, the properties of which are most often unknown, and are also nonstationary in space and time. Under such conditions, it is not clear to what extent the mode representation obtained in numerical models corresponds to reality. The authors studied the mode structure of several shallow water bodies and the coastal shelf of the White Sea. In the case when it was possible to measure the vertical profile of the field at the receiving point, the mode profiles are easily distinguished and can be used, for example, to determine unknown boundary conditions at the bottom and surface, including in the presence of ice cover. A method has been developed for identifying modes in the case of field reception by single spaced hydrophones; the difficulty in this case is that at each moment of time the received signal contains all propagating modes that have to be selected in subsequent processing.
Three-dimensional numerical analysis of acoustic energy transfer in air-jet instrument
Authors: Tabata Ryoya , Midorikawa Hiroko , Kobayashi Taizo , Takahashi Ki’nya
Published: June 2021

In this presentation, we will discuss acoustic energy transfer in a recorder-like air-jet instrument at a low Strouhal number. We will share the methods and results for a three-dimensional numerical analysis of acoustic energy transfer estimated using Howe’s energy corollary, based on the results of a large eddy simulation. The results are remarkably stable compared with previous two-dimensional numerical results, allowing us to consider the relative timing of the energy transfer with respect to the jet displacement. We will show that three-dimensional analysis is essential, especially when considering the energy transfer due to vortex shedding above and below the pipe edge (labium).
Using Navier–Stokes modeling to design a better recorder
Authors: Thacker Jared W.
Published: June 2021

The recorder family consists of several instruments of varying musical compasses. A musical tone is established by blowing into the mouthpiece of the instrument and a standing pressure wave is formed in the resonator of the instrument. Blowing harder into the instrument can cause a transition from the original (lower frequency) note to a higher (frequency) note. This transition is often referred to as “regime-change.” Recorder players have told us that regime-change in the bass recorder can happen at significantly lower blowing speeds for notes at the lower end of its musical compass. In this talk, regime-change is studied using Navier–Stokes based modeling in simplified models of sopranino and bass recorders. We show how the geometry beneath the labium of the recorder can be modified in order to alter regime-change behavior and extend the blowing range of the lowest notes in the bass recorder. In addition, these computational results are verified through experimental studies using 3D printed recorders and dimensions inspired by the modeling results.