bluuebunny/crossref_metadata_2025 huggingface dataset:
Reconstruction of sparse ocean noise fields with generative neural networks
Authors: Thilges Kayla , Plumley Meredith , Zuberi Zaki , Delmerico Sam , Einstein Craig , Ramamurti Adith , Summers Jason E.
Published: November 2021

Modeling the underwater noise field offers important insights for underwater navigation, assessing noise impacts, and establishing noise budgets. In situ measurements of the noise field are often sparse with limited information about spatially distributed underwater acoustic fields. In this work, we demonstrate the use of a generative neural network for estimating noise fields over regions not directly measured. An ARiA developed ambient noise model is used to generate noise fields for various ocean noise-source scenarios. The model output includes vertical directionality, depth dependence, and incorporates multiple sources of sound, including anthropogenic, biologic, and environmental. We train generative models on these simulated spatial noise distributions a priori. These generative models are able to take sparsely sampled noise measurements and construct the spatial distribution of the noise field. The generative model learns the spatial distribution by minimizing the point-to-point difference between the generated fields and the true fields at each step while also maximizing the fidelity of the general distribution of the generated noise fields to the true fields. Through a nested generative model approach, along with auxiliary sound-speed-profile information, the local field is used to extrapolate the noise field to larger spatial scales.
Ship detection from passive underwater acoustic recordings using machine learning
Authors: Alvaro Alejandro , Schwock Felix , Ragland John , Abadi Shima
Published: November 2021

The Ocean Observatories Initiative (OOI) hydrophone data contains a rich collection of ship passage events that can be leveraged for passive ship detection. This study uses 6 years of OOI acoustic data collected by the hydrophone located at the southern foot of the Axial Seamount volcano with a sampling rate of 200 Hz. Ship location data from the Automatic Identification System (AIS) is used to predict the presence or absence of ships within an effective radius of the hydrophone, estimated to be 15 km. After, identifying ships with similar acoustic profiles, such as commercial carrier, tanker, cargo, container, and supply ships, a balanced dataset is created with an even distribution of ships within and outside of the estimated radius. The final dataset is separated into a training (70%), validation (10%), and test (20%) dataset, and then used to create k-nearest neighbors (KNN) and logistic regression models using the scikit-learn Python library. The KNN model achieves the best performance and classifies the ships with an accuracy of 98.04%. This shows that it is possible to determine the presence of ships from passive underwater acoustic recordings with high accuracy. [Work supported by the SURIEA program and ONR.]
Topological deviation of membrane waves as a model of gravitational lens effect
Authors: Catheline Stefan , Delattre Victor , Laloy-Borgna Gabrielle , Faure Frederic , Fink Mathias
Published: November 2021

Elastic membranes are often used as didactic demonstration of gravitation from the general relativity perspective. Indeed, trajectories of rolling spheres such as billiard balls influence each other through the deformation their mass print within the membrane tissue as would the space-time curvature of gravity. The analogy is pushed here using membrane waves. Indeed, rules of topology apply to masses and waves. We show through experiments and curved manifold simulations that wave propagation due to topological deviation of a two-dimensional flat fabric membrane, justifies classical analogy with gravitational lenses. This allows revisiting through membrane waves, the famous 1919 Eddington experiment that demonstrated light deviations of stars in the vicinity of the sun. It is our hope that the experiment described here will provide new insight for the testing of geometry effects on wave propagation. Also, inspired by acoustic metamaterials, it is our hope to use a more correctly constructed membrane to observe quantified exchanges of geometric waves with their elementary mesh.
Generation of a focused nonlinear difference frequency using high-amplitude time reversal focusing of airborne ultrasound
Authors: Anderson Brian E. , Wallace Carla
Published: November 2021

Time reversal (TR) focusing of high-amplitude airborne ultrasound can be used to create a difference frequency. Methods are employed to increase the amplitude of the focus. These methods include creating a miniature reverberation chamber, using multiple sources, and using the clipping processing method. The use of a beam blocker to make the sources more omnidirectional is also examined, and it is found that for most source/microphone orientations, the use of a beam blocker increases the amplitude of the focus. A high-amplitude focus of 134 dB peak re 20 μPa sound pressure level with a center frequency of about 38 kHz is generated using eight sources. Then, using four sources centered at 36.1 kHz and another four sources centered a 39.6 kHz, nonlinear difference frequency content centered at 3.5kHz is observed in the focus signal. The difference frequency amplitude grows quadratically with increasing primary frequency amplitude. When using beam blockers, the difference frequency content propagates away from the focal location with higher amplitude than when beam blockers are not used. This is likely due to the differences in the directionality of the converging waves during TR focusing.
Experimental measurement for assessing pseudo-sound effect in parametric array
Authors: Song Jiyoung , Jung Donghwan , Kim J. S. , Lee Jaehyuk
Published: November 2021

The parametric array that generates narrow beams at low frequencies with apertures shorter than the wavelength and has been widely investigated when measuring the acoustic characteristics of materials, such as sound transmission and reﬂection properties. Because the parametric array utilizes nonlinear interaction across the frequency components, nonlinear phenomena arise in both the acoustic medium and the hydrophone. The unwanted nonlinear sound generated in the hydrophone and instrumentation is termed pseudo-sound. This work devised an experiment to measure the pseudo-sound for the purpose of isolating the “real” nonlinear difference frequency sound from the total nonlinear sound. Experimental results were validated by comparing its results with the pseudo-sound measured with a truncator (i.e., acoustic filter) to identify hydrophone nonlinearity.
Sonopermeation to deliver topotecan using lipid-prodrugs, liposomes, and microbubbles
Authors: Marquez Mendi G. , Gomez Paula , Ghaderi Mohammadaref , Sirsi Shashank , Hernandez Sonia , Frolova Liliya , Tartis Michaelann
Published: November 2021

Sonopermeation using microbubbles is an emerging extracorporeal drug delivery technique for impenetrable tumors. Utilizing the sonopermeation effect while enhancing the bioavailability of clinical chemotherapeutics using nanoparticle strategies is a potentially powerful combination. Clinically available topotecan, a chemotherapeutic, has limited bioavailability and therapeutic efficacy, which is attributed to poor solubility, rapid clearance, and inactivation under physiologic conditions. To overcome this, topotecan has been conjugated with phospholipids converting it into a lipid-prodrug (2T-T) for use in lipid-based carriers, such as liposomes, for sonopermeation. In this presentation, we present the characterization results of topotecan lipid-prodrug liposomes, preliminary in vitro efficacy in several neuroblastoma cell lines, and in vivo proof-of-concept in neuroblastoma xenograft tumors. Lipid-prodrug characterization demonstrates stable, high-drug loading liposomes are attainable while maintaining cytotoxicity. Liposome formulations, analyzed using ultraviolet-visible spectrometry and dynamic light scattering, indicate peak incorporation limits are attained for 100 nm extruded 60 mol. % 2T-T liposomes with no change in size over a 2 month period. In vivo xenograft neuroblastoma studies co-injected with lipid-prodrug liposomes (40 mol% 2T-T, 10 mg/kg) and microbubbles, for sonopermeation, were performed to determine the extent of 2T-T delivery with sonoporation over liposomal delivery alone at 24 hours post-treatment.
Bubble nuclei in polyacrylamide hydrogels
Authors: Rawnaque Ferdousi Sabera , Simon Julianna
Published: November 2021

Bubble nuclei have been studied extensively in water for over 50 years with nuclei categorized as homogeneous or heterogeneous. However, it is unclear how those nuclei identified in water translate to viscoelastic hydrogels or tissues. In this study, bubble nuclei were evaluated in 17.5%, 20%, and 22.5% v/v% polyacrylamide (PA) hydrogels (n = 3 each). A 1.5 MHz focused ultrasound transducer was used to induce cavitation using 10-ms pulses with pressures ranging up to p+ = 8 = 89 MPa, and p− = 2 = 26 MPa and -6 dB focal dimensions of 9.4 × 1.15 mm2 (p−). Cavitation size and location were monitored with high-speed photography. When the concentration of PA increased from 17.5% to 20%, the area occupied by bubbles at 0.07 ms decreased from 0.14 mm2 to 0.06 mm2. The location of acoustic cavitation for replicate exposures in the 17.5% gel at 0.07 ms became more consistent as the acoustic pressure increased with no bubble overlap at p− = 2 = 21MPa and 18% bubble overlap at p− = 2 = 26MPa. These results suggest acoustic cavitation in PA hydrogels is dependent on the availability of bubble nuclei at each driving pressure. Future work includes investigating the distribution of bubble nuclei in tissues. [Work supported by NSF CAREER 1943937 and PSU Riess Fellowship].
Proton dosimetry using superheated droplets: Quantification with ultrasound
Authors: Collado-Lara Gonzalo , Heymans Sophie V. , Rovituso Marta , Vos Hendrik , D'Hooge Jan , de Jong Nico , Van Den Abeele Koen , Daeichin Verya
Published: November 2021

Superheated nanodroplets were proposed for dosimetry in proton therapy. Proton energy deposition within the droplet core leads to droplet vaporization. Vaporizations can be localized through acoustic pulse-echo, and used to measure the proton stopping distribution. Since protons can only lead to vaporizations as they stop, the probability of vaporization is estimated as the probability of a proton stopping within a droplet. Assuming that the number of vaporizations follows a binomial distribution, conversion from vaporizations to number of protons requires knowledge of: droplet size distribution and concentration, and acoustic FoV volume. Here we address the latter. We propose an experimental and numerical method to characterize the 2-way acoustic elevational width of a linear array. First, the impulse response and 1-way field of the acoustic array was measured using a hydrophone. Then, the 1-way field was fitted to field-ii simulations using a least-squares algorithm to estimate the optimal parameters. Finally, the 2-way acoustic field was simulated. The effective elevational width depends on the scattering cross section of the resulting microbubbles, and was determined from the experimental range of backscattering intensities. The method allowed to predict the vaporization counts of experimental measurements where three different size-sorted droplet populations were used.
Noninvasive and cell-type specific neuromodulation by integrating ultrasound and genetics
Authors: Yang Yaoheng , Pacia Christopher P. , Ye Dezhuang , Zhu Lifei , Yue Yimei , Yuan Jinyun , Miller Mark , Cui Jianmin , Joseph Culver , Bruchas Michael , Chen Hong
Published: November 2021

The investigation of brain functions and treatment of brain disorders requires modulation of selected neurons in a noninvasive manner in the deep brain. To achieve this goal, sonogenetics has been developed that involves the use of focused ultrasound (FUS) to selectively control a specific type of neurons that have been genetically modified to express ultrasound-sensitive ion channels. Existing sonogenetic techniques utilize ultrasound mechanical effect to activate mechanosensitive ion channels. Different from existing approaches, we aimed to develop sonothermogenetics for noninvasive, deep-penetrating, and cell-type-specific neuromodulation by combining a thermosensitive ion channel TRPV1 with FUS-induced brief, non-noxious thermal effect. FUS sonication at the mouse brain in vivo selectively activated neurons that were genetically modified to express TRPV1. Temporally precise activation of TRPV1-expressing neurons was achieved with its success rate linearly correlated with the peak average temperature within the FUS-targeted brain region as measured by in vivo magnetic resonance thermometry. FUS stimulation of TRPV1-expressing neurons of the Parkinsonian circuit at the striatum repeatedly evoked rotating locomotor behavior in freely moving mice. FUS sonication was confirmed to be safe based on inspection of neuronal integrity, inflammation, and apoptosis markers. In summary, our study demonstrated that sonothermogenetics is a noninvasive and cell-type-specific neuromodulation technique.
Focused ultrasound immunomodulation on mononuclear phagocytes in the brain
Authors: Sun Tao , McDannold Nathan J.
Published: November 2021

Focused ultrasound (FUS)-mediated blood–brain barrier opening is an attractive method of treating neurological diseases, such as glioblastoma (GBM) and Alzheimer’s disease (AD). As an established drug delivery approach, FUS has also been associated with the stimulation of neuro-inflammation, including the morphological activation of resident microglia. Here we report FUS immunomodulation effects may also include the enhanced recruitment and activation of other mononuclear phagocytes in murine models of GBM (GL261) and AD (APP/PS1dE9) in tests with or without monoclonal antibody-based passive immunotherapy. Immunoprofiling via flow cytometry and immunofluorescent staining were performed in the harvested brains. In the GBM model, our results demonstrated that FUS enhanced antigen presentation behaviors of tumor-associated macrophages without affecting the microglia. FUS also reprogrammed the macrophages locally towards the anti-cancer phenotype. In the AD model, plaque-associated Ly6G+ phagocytes were only present in FUS-treated areas, while microglia activation was found in both antibody-treated groups. Taken together, our results offer new evidence in FUS immunomodulation on the myeloid compartment of the brains in GBM and AD-like mouse models.
Spectral proper orthogonal decomposition analysis of flowfield for supersonic nozzle jet noise reduction
Authors: Zheng Zhongquan C. , Zhang Meihua , Wang Zhijian
Published: November 2021

Spectral proper orthogonal decompositions (SPOD) is the frequency domain form of proper orthogonal decomposition (POD). SPOD is shown to be directly applicable to jet noise studies. A computational SPOD analysis is performed on the Large-Eddy Simulation (LES) computational data for both the baseline nozzle flow and a modified nozzle flow. The mode energy analysis from SPOD shows that for the baseline nozzle, the low-rank behavior is found at frequencies at which a large separation occurs. The low-rank behavior disappears for the modified nozzle flow where no significant peaks are detected. The coherent structures of the low frequency show the Kelvin–Helmholtz type instability. It is also shown that the reconstructed flow field using the first decades of SPOD modes can capture the major shock-expansion based interactions that are present within the original flow field. This suggests that the method of SPOD-based reconstruction can be used to carry out additional modal and acoustic analyses of jet flows.
On the use of numerical Green’s functions in acoustic analogies for edge noise prediction at low Mach number
Authors: Trafny Nicolas , Cotté Benjamin , Serre Gilles , Mercier Jean-François
Published: November 2021

The interaction between a turbulent flow and a rigid obstacle leads to a far-field broadband acoustic radiation which can have a significant impact in many industrial applications. Depending mainly on the Mach number, different prediction methods have been developed. At low Mach number, direct noise computation methods are too expensive. Other approaches must be chosen, based on acoustic analogies which consist in separating noise generation and noise propagation mechanisms. In this study, we focus on the Lighthill’s wave equation solved using both analytical and numerical tailored Green’s functions. The latter is computed using an accelerated Boundary Element Method. Also, a statistical model for the velocity fluctuations in the turbulent flow is used to estimate the far-field radiated noise spectrum. It can be built from either a simulation of the mean flow or an estimation of the boundary layer parameters. To validate numerical predictions for the far-field acoustic pressure spectrum, a NACA 0012 airfoil is considered. Both leading edge and trailing edge predictions are validated against experimental data. Moreover, the impact of both the inflow velocity and the angle of attack on spectra and directivity diagrams is investigated.
Signal Processing: Data analysis, machine learning, and communications
Authors: Edelmann Geoffrey F.
Published: November 2021

Whether it is communicating to an autonomous underwater vehicle, finding a defect in an airplane’s wing, focusing sound to destroy kidney stones, or learning how bats track their food, advanced signal processing is key to successful research. The Technical Committee on Signal Processing in Acoustics was formed to foster interdisciplinary interaction among the Technical Committees. This broad discipline covers such unique topics as detection, tracking, classification, communications, machine learning, environmental analysis, focalization, robotics, and their application to ships, animals, speech, earthquakes, medicine, environmental knowledge, and unmanned vehicles, as well as future problems yet undiscovered. This presentation will highlight some of the exciting techniques being used in signal processing and in the process give an appreciation for the breadth of the applications of the techniques being developed.
An introduction to Psychological and Physiological acoustics
Authors: Best Virginia
Published: November 2021

The technical committee on Psychological and Physiological acoustics (P&P) encompasses a wide and multidisciplinary range of topics. It is concerned with questions of what happens to sound once it enters the auditory system, and how sound is processed to facilitate communication and navigation. Topics include the biomechanics of the middle and inner ear; the neuroscience of the auditory nerve, brainstem, and cortex; and behavioral studies of auditory perception and cognition. Within these topics, research covers both normal function and effects of hearing disorders, as well as applied questions related to hearing aids, cochlear implants, and audio technology. The scope of P&P overlaps heavily with that of several other technical committees in ASA, especially Architectural Acoustics, Animal Bioacoustics, Noise, and Speech Communication. This presentation will provide an overview and some examples of currently active areas of investigation.
Introduction to the Musical Acoustics technical area
Authors: Piacsek Andrew A.
Published: November 2021

The field of musical acoustics encompasses all aspects of the design, construction, and performance of musical instruments (including the voice), as well as the physical and cultural environment in which they are played, with the goal of understanding how these elements contribute, separately or together, to the acoustic characteristics. While the general acoustic behavior of most musical instruments can be explained in terms of fundamental principles governing waves in strings, pipes, and plates, there is a high degree of complexity in the mechanical motion and the resulting sound that enables a rich variety of tonal character and musical expression. This presentation will provide an overview of current research areas that address the complexity and variety of musical instruments and the listener experience, including nonlinear effects, flow-structure interaction, computational modeling and machine learning, measurement techniques, performer-instrument interaction, and recording/playback technology. Along the way, the relevance of other technical areas of acoustics will be noted, including physical acoustics, structural acoustics, signal processing, computational acoustics, and psychological and physiological acoustics.
Architectural Acoustics: How does that building sound?
Authors: Jaramillo Ana M.
Published: November 2021

Architectural acoustics is the area that studies sound in and around buildings. Sometimes the requirements call for good acoustic quality for music performance and sometimes for clear speech intelligibility. Additionally, architectural acoustics also deals with issues of unwanted sound in buildings and speech privacy. TCAA very often crosses interests with TCN, and sometimes with other technical areas in the ASA. This presentation will cover typical and current topics, as well as details about the Committee membership and activities.
Introducing the Structural Acoustics and Vibration Technical Committee
Authors: Naify Christina J.
Published: November 2021

The Structural Acoustics and Vibrations Technical Committee (TCSA) includes scientific study of vibrating structures, excited using either elastic or acoustic waves, and radiated acoustic fields from those structures. The committee members study a diverse range of physics relating to these basic phenomena, from damping and isolation, to active control, to modal response and a variety of techniques are used, including numerical modeling, analytical techniques, and experimental measurements. Due to the wide range of applications in which vibrating structures are found, TCSA is multidisciplinary, with ASA meeting sessions often co-chaired with Physical Acoustics, Engineering Acoustics, Signal Processing to name a few. Additionally, research fields span a range of disciplines in their practice, including industry, academia and government. This talk will provide a brief overview into TCSA including historical highlights and future directions as well as summaries of some of the recent special sessions presented at Acoustical Society meetings.
Babies, bubbles, and brain disease: An introduction to the Biomedical Acoustics Technical Committee
Authors: Bader Kenneth B.
Published: November 2021

For most folks, ultrasound in medicine is associated with fetal imaging, and it remains among the most widely available and frequently used imaging modalities in the clinic. Recent advances have expanded the capacity of ultrasound imaging to include the ability to quantify mechanical properties of tissue (elastography), microvascular structure (super resolution imaging), perfusion (contrast imaging), and molecular expression such as oxygenation (photo-acoustic imaging). Effective diagnostic information is now possible for targets traditionally avoided by ultrasound imaging, such as lung for COVID-19 diagnoses. Ultrasound energy can also be harnessed for therapeutic purposes. Focused sources enable us to ablate malignancies through thermal or mechanical-based mechanisms. A strong tumor immune response has been observed for histotripsy, a bubble-based ablation method, potentiating a means to treat multi-focal disease. Ultrasound-mediated bubble activity enhances drug delivery to improve treatment for thrombo occlusive disease (e.g., heart attack, stroke, venous thrombosis), cancer, and tissue regeneration. Improved drug delivery is also possible in the brain via ultrasound-mediated opening of the blood brain barrier. Separate from drug delivery, ultrasound can induce neuromodulation for the treatment of essential tremor, neuropathic pain, and Parkinson’s disease. Diagnostic and therapeutic ultrasound continues to advance the field of medicine, and are integral for improving the outcomes for debilitating diseases.
Introduction to the Technical Committee on Engineering Acoustics
Authors: Haberman Michael R.
Published: November 2021

This talk will introduce ongoing work in the Technical Committee on Engineering Acoustics (TCEA) of the Acoustical Society of America, which is one of the most diverse Technical Committees of the Society. Engineering Acoustics encompasses the theory and practice of creating tools to generate and investigate acoustical phenomena and then to apply the knowledge of acoustics to practical utility. This includes the design and modeling of acoustical and vibrational transducers, arrays, and transduction systems in all media and frequency ranges. It is also concerned with the design of acoustical instrumentation, metrology, and the calibration of those systems. It further considers all aspects of measurement, fabrication, and computational techniques as they relate to acoustical phenomena and their utility. The talk will provide an introduction of a broad range of research topics in TCEA, with specific highlights on exciting new areas of research.
Case study of variable refrigerant flow fan noise
Authors: Woolworth David S.
Published: November 2021

This paper presents a case study of multiple VRF units measured during building commissioning and the field data is compared to the manufacturer data provided.
VRF noise: From data sheets to field measurements
Authors: Tracy Tyler
Published: November 2021

In the last 20 years, Variable Refrigerant Flow (VRF) systems have gained prominence in many sectors of U.S. construction. These devices move conditioned refrigerant from outdoor units through pipes to indoor units, serving areas that require heating or cooling. Advantages of a VRF system include eliminating the need to carry conditioned air through long runs of ductwork, allowing more environmental control in each space or zone served, and offering quieter operation levels. Indoor VRF system noise levels provided by manufacturers are often measured in anechoic conditions close to the unit, which is in contrast to the installed conditions in many buildings using VRF systems. We seek to explore the existing literature documenting VRF sound levels, while we compare and contrast these sound levels to field-installed VRF system measurements.
Challenges and conundrums
Authors: Conant David A. , Hoover K. Anthony
Published: November 2021

Various noise and vibration control experiences will be described, with data presented where available. Project types range from performing arts to offices, large to small, near and far. Some solutions were surprisingly straightforward, others were simply surprising, and others seemed fairly inventive. Some resisted predictive approaches or were hampered by questionable “data.” Several noise issues turned out to be unrelated to the MEP system, and for one or two conundrums we will welcome your insights. Often, such experiences can often offer useful approaches where conventional wisdom fails, and these war stories are the most fun to share.
Mechanical noise control case studies
Authors: Keefe Joseph
Published: November 2021

A few case studies of mechanical system noise are presented. These address before/after background sound levels associated with room and/or mechanical system modifications, comparison of predicted mechanical system noise to measured values, our approach to noise control recommendations, and lessons learned. Interesting cases include a college theater renovation, office noise control involving implementation of a fan array and a VFD, and a challenging hunt for the source of an exterior pharmaceutical campus noise source generating complaints in a nearby neighborhood.
Some physical acoustics research supported by Logan E. Hargrove
Authors: Maynard Julian D.
Published: November 2021

As a Scientific Officer for the Office of Naval Research, Logan Hargrove would support research which addressed Navy problems, such as making ships quieter. Logan recognized that this problem could be tackled with nearfield acoustical holography (NAH), which, unlike conventional holography, could image sources with a resolution not limited by the wavelength of the radiation. NAH was cited as one the Navy's 35 big achievements in 75 years. A related problem was sound radiation from a rib-stiffened plate; in this case it was conjectured that a condensed matter physics concept, Anderson localization (cited in a Nobel prize), could be used to reduce noise radiation from a plate. Logan supported this research, and extended it to include research with other condensed matter concepts merged with acoustics. This led to an acoustic model of a quasicrystal formed with 150 musical tuning forks coupled in a Penrose tile pattern. While the Navy was indeed interested in novel materials such as alloy quasicrystals, Logan was pleased that part of his supported research, the tuning fork quasicrystal, was featured in the New York Times (September 5, 1989, Science Section).
Logan Hargrove and thermoacoustics
Authors: Muehleisen Ralph T.
Published: November 2021

In his time as a Scientific Officer for the Office of Naval Research (ONR), Logan Hargrove supported a number of research areas in physical acoustics including non-linear acoustics, resonant ultrasound spectroscopy, sonoluminescence, and thermoacoustic heat engines and refrigerators. In the 1980s, 1990s, and 2000s, Logan provided support in thermoacoustics for dozens of students, postdocs, faculty, and researchers throughout the US resulting in dozens of papers, reports, and patents and spurring the creation of several small businesses. This presentation provides an overview of some of the thermoacoustics related projects and the lasting impact Logan's thermoacoustic funding has made.
Logan Hargrove and nonlinear acoustics
Authors: Hamilton Mark F.
Published: November 2021

Logan Hargrove became involved in nonlinear acoustics as a master’s student at Oklahoma State University under George Thurston, research that led to the 1957 JASA paper “Nonlinear Properties of Circular Orifices.” His involvement continued as a doctoral student under Egon Hiedemann at Michigan State University, where he published the 1960 JASA letter “Fourier Series for the Finite Amplitude Sound Waveform in a Dissipationless Medium.” The letter was part of his research on the use of optical methods to characterize sound fields, which culminated in Hargrove and Achyuthan’s 1965 Physical Acoustics series chapter “Use of Light Diffraction in Measuring the Parameter of Nonlinearity of Liquids and the Photoelastic Constants of Solids.” Following his subsequent employment at Bell Laboratories, where he worked primarily in optics and reported the first demonstration of a mode-locked laser, Logan became a scientific officer at the Office of Naval Research and began funding basic research in nonlinear acoustics. This presentation provides an overview of the research projects and graduate students in nonlinear acoustics that were funded by Logan at UT Austin for nearly three decades. Part of Logan’s legacy is that many students he funded perform research in nonlinear acoustics to this day.
Logan Hargrove’s greatest contribution to the University of Mississippi
Authors: Raspet Richard , Hickey Craig J.
Published: November 2021

We believe that Logan always felt that the people and community of Physical Acoustics were the most important product of his ONR research program. In particular, the PhD students who were able to receive degrees and continue to work in Physical Acoustics after graduation were dear to him. A characteristic of his funding was that he always provided sufficient funds for tuition, salary for the student, summer salary for the PI, and travel to ASA meetings to present the work and to interact with others PI’s and students in Physical Acoustics. We are very thankful for his support and will talk about the students supported by Logan at the University of Mississippi over the last four decades.
Egyptian fruit bats exhibit precise 3D spatial memory that eclipses sensory information
Authors: Yin Xiaoyan , Moss Cynthia
Published: November 2021

Egyptian fruit bats (Rousettus aegyptiacus) have well-developed vision and lingual echolocation, which provide complementary sensory information to execute natural behaviors, such as obstacle avoidance and landing. However, spatial memory can reduce the computational load in natural tasks and there is evidence that bats sometimes fail to use sensory information when they operate in familiar surroundings. Here we investigate the precision of this bat species’ spatial memory for a landing location when it has access to vision and sonar echoes and when it has access to sonar echoes alone. Animals were trained for about 10 days to find a 5 cm diameter landing platform at a fixed location in a 2.5 × 6 m2 flight corridor and later tested when the landing platform was shifted in azimuth and elevation by 5–30 cm. The bat’s 3D flight trajectory was tracked with high-speed video cameras and its sonar inspection of objects was quantified with an ultrasound microphone array that permits reconstruction of the sonar beam aim. Our data suggest that spatial memory in Egyptian fruit bats is highly precise and eclipses multimodal sensory information. This bat species’ robust reliance on 3D spatial memory may support long-distance navigation and forage in the natural environment.
Performance evaluation on three-forced choice pure tone audiometry in open space environment
Authors: Arifianto Dhany , Azmi Fiqiyah U. , Ashilah Naomi , Herlambang Bagus A. , Purnami Nyilo
Published: November 2021

In this report, we investigated the performance comparison of Three-Forced Choice (3AFC) with a pair of Bluetooth-connected active noise cancelling headphones and Two-Forced Choice (2AFC) in an audiological booth for audiometry examination. The procedure was essentially to generate mono pure tone on six different frequencies with adaptive loudness level to both left and right ear, respectively. The subject presented the pure tone, then he or she pressed a button. If it is right than the loudness level will be lowered until it is inaudible. This level was marked as the hearing threshold of the subject. We recruited 38 normal-hearing subjects who underwent to an audiology clinic for audiometry examination (using the gold standard, 2AFC technique). The recorded responses were statistically analyzed using non-parametric Wilcoxon test with Bonferroni correction. The audiometry results using the outdoor 3AFC method on 2000 Hz and 4000 Hz have mean-differences closer to ISO 226 accuracy reference for all 38 participants. These results suggested that the proposed technique may replace the gold standard.
Effects of modulator shape at thresholds and supra-thresholds spectral modulation perception
Authors: Isarangura Sittiprapa , Eddins Ann C. , Seitz Aaron , Gallun Frederick J. , Eddins David A.
Published: November 2021

Spectral modulation detection is common method to assess spectral envelope perception in research and clinical settings. Prior investigations into spectral modulation (SM) detection have used two different modulator shapes: a sinusoidal envelope on a logarithmic amplitude scale or a sinusoidal envelope on a linear amplitude scale. The former creates a sinusoidally shaped excitation pattern, while the latter creates an excitation pattern with broad peaks and sharp valleys. What impact, if any, modulator shape has on SM perception at detection threshold or at supra-threshold levels is unknown. To investigate potential perceptual differences between waveform shapes: (1) SM detection was measured for modulation frequencies ranging from 0.5 to 8.0 cycles/octave; (2) Spectral modulation masking was measured for SM frequencies of 0.5 and 2.0 cycles/octave. The SM phase of the masker was manipulated (0, 90, or 180 degrees) so that maskers had a peak, a midpoint, or a valley at 1147 Hz. Tone detection (1147 Hz) was measured for the logarithmic and linear sinusoidal SM envelope shapes for each of the three phases. Results revealed significant differences between the two spectral envelope shapes for both spectral modulation detection and for spectral modulation masking. [Work supported by NIH R01DC015051].
Energetic/informational masking and listening effort, as measured by electroencephalography and pupillometry
Authors: Villard Sarah , Alam Ayesha , Perrachione Tyler K. , Kidd Gerald
Published: November 2021

Measuring the listening effort exerted by an individual to understand speech under auditory masking conditions can provide vital information that is not available from accuracy scores alone. The goal of this study was to compare the amount of listening effort elicited in young, normal-hearing subjects during a noise masking condition producing primarily energetic masking (due to spectrotemporal overlap between target and maskers) versus during an intelligible speech masking condition producing a high degree of informational masking (additional masking due to listener uncertainty; e.g., target-masker confusions). Listening effort was measured simultaneously using two physiological metrics: alpha power (via electroencephalography) and pupil dilation. The target speech comprised 5-word matrix-style sentences in both conditions. The target was presented at 0 deg azimuth, and the maskers were presented at ± 45 deg azimuth. In each condition, the target-to-masker ratio was set at each subject’s 75% correct point on the psychometric function. Preliminary results suggest that the intelligible speech masking condition elicits a higher degree of listening effort than the noise condition. This finding is consistent with the view that greater effort is involved in ignoring acoustically and linguistically similar sources than highly dissimilar, low-information value sources. [Work supported by NIH K99DC018829.]
Dynamic functional connectivity in auditory attention task
Authors: Drew Jordan , Larson Eric , Foti Nicholas , Nadkarni Rahul , Fox Emily , Lee Adrian KC
Published: November 2021

Navigating conversations in complex auditory environments requires dynamic control of attention—switching and maintaining attention across multiple auditory objects. Several brain regions, some traditionally considered auditory and others non-auditory, have been highlighted as part of the cortical networks that contribute to the ability to switch and maintain attention between multiple talkers. M/EEG data were collected during a dual-stream auditory attention task in which the listener was asked to attend to one of two speech streams that differed in location or pitch. In each trial, the listener was cued to either maintain their attention on one talker, or switch their attention to the second talker during a silent interval. In this study, we apply a state-space model to the brain imaging data to elucidate the differences in the dynamic cortical networks responsible for maintaining and switching attention across different auditory cues.
Hemispheric lateralization during spectral envelope perception is dynamic and individualized
Authors: Eddins Ann C. , Isarangura Sittiprapa , Lutfi Robert A.
Published: November 2021

The spectral envelope is an important acoustic cue for vowel and consonant perception. Sensitivity to the spectral envelope is commonly studied with a spectral modulation detection task in which two co-occurring spectral cues (spectral modulation—SM, carrier frequency—CF) may be available. Neuroimaging studies indicate that spectral cues are often processed asymmetrically in the cortex, but it is unknown if such lateralization depends on perceptual weighting of the available cues. Here we simultaneously measured SM discrimination and electroencephalography (EEG) in young adult listeners in a single-interval, two-alternative task during passive and active attention conditions as well as in a separate perceptual decision-weights task. Using condition-on-a-single-stimulus (COSS) analyses, individual differences in perceptual weights of spectral cues (SM, CF) were obtained for each listener. EEG source localized results showed that hemispheric lateralization was dynamically modulated over time between left and right auditory cortices and that lateralization was dependent on individual perceptual weighting patterns for SM and CF. [Work supported by NIH/NIA P01-AG09524 (ACE) and NIH/NIDCD R01- DC001262 (RL, ACE).]
Sensitivity to Schroeder phase arising from sensitivity to temporal patterns across nerve fibers
Authors: Lu Hsin-Wei , Smith Philip H. , Joris Philip X.
Published: November 2021

The flat-envelope harmonic complexes devised by Schroeder (1970) have been extensively used in psychophysical studies. The stimuli contain a linear frequency sweep, whose direction and speed depend on phase curvature C. For a given characteristic frequency, basilar membrane and nerve responses show only a subtle dependence on the sign and magnitude of C. The question arises whether CNS neurons are sensitive to the temporal pattern across nerve fibers. We studied octopus cells in the cochlear nucleus, which receive a convergent excitatory input from nerve fibers and have been hypothesized to be monaural coincidence detectors. We studied both their spike output and nerve input using multiple recording techniques in anesthetized chinchillas. Octopus cells showed marked sensitivity to C, which was broadly stable across SPL and fundamental frequency. They were tuned to a wide frequency range, but with discrete frequency “hotspots” that generate major and minor inputs. The sensitivity to C arises not from coincidence detection, but from a sensitivity to the temporal sequence of activation of inputs tuned to different frequencies. We conclude that marked sensitivity to Schroeder phase is already present at the first CNS processing stage, based on temporal sequence detection across frequency channels rather than on coincidence detection.
Wave propagation in a continuum nonlinear phononic material with soft nonlinear elastic layers
Authors: Smith Elizabeth , Matlack Kathryn
Published: November 2021

This presentation discusses modeling the propagation of nonlinear waves in a continuum phononic material. This system is shown to exhibit amplitude-dependent response and energy transfer between frequencies, which are well studied phenomena of nonlinear discrete systems, but are relatively unexplored in fully elastic continuum models. The phononic material is composed of repeated layers of stiff and soft materials, and the nonlinearity is introduced through a nonlinear hyperelastic Gent model in the soft material. We analyze the dispersion of the linearized system using Bloch-wave analysis to identify band gaps in the system, and we use full-scale time-domainfinite element simulations to analyze the dynamic behavior of the system. Generation of zero frequency and second harmonic frequency amplitudes as well as their accumulation with distance are observed, and the influence of phononic band gaps on nonlinear wave propagation are described. We explore the influence of material nonlinearity in soft materials in continuum phononic materials as a mechanism for control of nonlinear wave propagation.
Magic phononic structures
Authors: Vongsiri Marupong , Carrillo-Munoz Maria , Sharma Bhisham
Published: November 2021

To alter the dynamical response of a structure, engineers must alter its overall mass or stiffness, frequently at the expense of functional performance. Here, borrowing from the field of recreational mathematics, we propose the idea of magic structures—a new class of structures with invariant global mass and stiffness properties, but varying dynamical response. A magic square is a special array of numbers where all individual rows, columns, and diagonals sum up to the same constant value, called the magic number. Here, working within the context of phononic structures, we treat the total mass of the structure as its magic property. We study the dispersion behavior of an infinite, periodic spring-mass system with a 3 × 3 square unit cell with the magic mass property. While maintaining the magic mass, we study the effect of various mass distributions on the dispersion bands and phononic bandgaps. Our analysis shows that the frequency and width of the phononic bandgaps occurring in such structures can be altered while maintaining the total mass of the structure at a constant magic value. Finally, we present a practical application by altering the density distribution of a 2D plate to create low-frequency bandgaps without altering its global mass.
On the acoustical performance of plenum window installed with rigid circular cylinders at low frequency
Authors: LAM Wai Kit , Tang Shiu Keung , Krynkin Anton , Dell Alexander
Published: November 2021

The low-frequency acoustical performance of plenum window with an array of rigid circular cylinders installed is analysed with the Finite Element Method (FEM) in the current study. This study includes the effect of vibrational glass boundaries, cavity resonance, the opening width of the window, and the arrangement of cylinders, on the sound transmission loss (TL) of the plenum window. The relationship between the above factors with TL is also investigated statistically and simple optimization of the geometry has been done based on the results. Results have shown that including the mechanical vibration of glass does not result in a significant difference with previous results, but an average decrease of 1 dB in TL is observed near the eigenfrequencies of the glass boundary. The effect of opening width on TL is not trivial but frequency-dependent due to the cavity resonance formed between the overlapping regions. Lastly, the introduction of rigid cylinders causes a shift of significant TL to lower frequency regardless of the opening width. The installation of them also seems to have destroyed the formation of cavity resonance, which results in much smaller TL.
Distributional properties of voice onset time in child speech and adult listener judgments
Authors: Hitchcock Elaine R. , Koenig Laura
Published: November 2021

Voice onset time (VOT) is well-recognized as the primary cue for perception of plosive voicing distinctions although perceptual judgments can also be affected by secondary cues, such as fundamental frequency (f0) and burst amplitude. Further, perceptual judgments may be influenced by distributional properties of the dataset, i.e., how VOT values are distributed along the continuum, and how many productions fall into each category in a listening test. This study assessed the impact of distributional characteristics of naturally produced child speech stimuli to determine their influence on listeners’ labeling behavior. The dataset comprised bilabial and alveolar CV words produced by 2–3-year-old English-speaking children. Six exemplars were chosen from six children for four groups: short-lag /b d/ and /p t/, long-lag /b d/ and /p t/. Within-category VOT distributions per POA were bimodal, separated by a 5 ms gap. Listening data were obtained from 20 adults. Preliminary data are consistent with our past experiments: Listeners were highly accurate (i > 90%) at labeling the production as intended by the child when the production matched the VOT category expected for the target word. Measures of f0 and burst amplitude suggest that secondary cues in the speech signal contributed to adults’ perception of children's stops.