bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of sleep on learning morphophonological alternations
Authors: Drake Shiloh , Preligera Isabel , Baese-Berk Melissa M.
Published: April 2023

In this experiment, we examine the contribution of sleep-based memory consolidation to the learning of morphophonological alternations in an artificial grammar. Periods of sleep after training seem to help participants to retain word formation patterns that they have previously learned, and also generalize learned word formation patterns to novel stimuli (Bryant et al., 2020; Dumay & Gaskell, 2007, 2012; Gomez, 2017; Gómez & Edgin, 2015; Sandoval et al., 2017; Simon et al., 2017). As our previous work has shown, Arabiclike morphology is particularly difficult for English-speaking participants to learn and retain, despite L1 transfer (Drake, under review), varying the type of instructions provided (Drake et al., 2022a), and multi-talker training (Drake et al., 2022b). In this ongoing work, we, therefore, compare participants’ accuracy rates after three periods of delay (no delay, delay without sleep, delay with sleep) to find out whether sleep aids in learning, generalizing, and retaining abstract morphological structure, and whether accuracy differs for the Englishlike or Arabiclike morphophonological alternations learned.
Predictive mechanisms in adaptive chunking during rapid extraction of meaning from spoken signals
Authors: Pittman-Polletta Benjamin , Dilley Laura
Published: April 2023

Speech understanding requires rapid of categorizations of auditory inputs. Neuronal rhythms play key roles in these computations; however, the principles by which timing, acoustics, and context are combined on-line to accomplish speech perception remain murky. Here, we outline a model of how temporal constraints sculpt meaning-making in speech processing according to an adaptively quasi-rhythmic process driven by fluctuations in certainty and predictability of timing and content. We propose that predictive mechanisms are leveraged to reduce possible identities of inputs based on prior inputs in which the smallest chunks of input can be rapidly compressed, recoded, and passed to higher representational linguistic levels. Evidence accumulation at each level of representation is used to assess likelihoods of candidate interpretations and their reliabilities at different timescales in a manner pegged to speech rate and situation-specific speed-accuracy tradeoffs. This synthesis illuminates mechanisms of human speech processing while making predictions for neuronal implementations and behavioral psychophysics.
Direct acoustic velocity vector measurements for evaluation of multichannel sound reproduction systems with signals of varied partial coherence
Authors: Driscoll Erin , Bocko Mark , Smith Sarah R.
Published: April 2023

In multichannel sound reproduction systems, the perceived virtual auditory scene is strongly influenced by inter-channel phase-shifts and the degree of mutual coherence among channel signals. Such degrees of freedom may be employed to effect an expanded virtual sound stage or a sense of spaciousness, but they also may lead to unwanted spectral coloration, diffuse or ambiguous virtual source locations, or startling and disorienting spatial image perceptions often described as “phaseyness.” Such effects may be described and understood in terms of the acoustic velocity in the vicinity of the listener. In this work we present theoretical predictions of the acoustic velocity vector for a stereo reproduction system with channel signals of varying phase and levels of mutual coherence, and we report direct measurements of the acoustic velocity vector employing a 3D sound intensity probe for several specific cases. Acoustic velocity vector predictions and measurements also are correlated with listener perceptions. The presented measurements are also compared to subjective localization of sound sources. The direct measurement of the acoustic velocity vector in spatial sound reproduction systems is a useful tool to quantitatively evaluate the performance of multi-channel spatial audio reproduction systems, to predict listener perceptions of the acoustic field reproduced by such systems, and to investigate the impact of early reflections in a room on localization.
Experimental demonstration of magnitude-only bearing estimation
Authors: Gravelle Christopher , Buck John R.
Published: April 2023

Traditional bearing estimation systems exploit relative time delays across an array of sensors to localize a target. While highly effective, such systems are costly and cumbersome. Yovel et al. (Science, 2010) found that bats steer their echolocation beams off axis to maximize the Fisher information, implying that spectral magnitude cues improve target localization. This presentation shares experiments demonstrating a man-made system estimating a target's bearing from echo spectrum magnitude-information using a single directional sensor with frequency dependence over the bandwidth of the signal. The output of a 31-element microphone array steered to broadside serves as the frequency dependent directional sensor. Moving a source transmitting a linear FM chirp across a range of angles estimates the beampattern of the receiver. Maximum likelihood estimation using these recorded replicas gives the mean-squared error (MSE) as a function of angle. The MSE is compared with the Cramer-Rao lower bound. Moving away from broadside reduces the received SNR, but paradoxically the MSE exhibits local minima. These MSE local minima are consistent with the optimal angles observed in previous research simulating the impact of magnitude cues (Kloepper et al., JASA-EL, 2018; Tidwell et al., IEEE SSPD, 2019). [Work supported by ONR MURI Program.]
Methods for high-performance jet aircraft noise source imaging and sound field reconstruction
Authors: Mathews Logan T. , Olaveson Tyce , Johnson Jon P. , Gee Kent L.
Published: April 2023

Source characterization and sound field reconstruction are vital to understanding noise radiation from turbulent, heated, supersonic jets produced by high-performance engines. This paper describes the application of two acoustic imaging methods to full-scale tactical aircraft noise analyses: statistically optimized near-field acoustical holography and hybrid beamforming. These methods constitute equivalent wave and equivalent source models, respectively. A review of these methods is given and their respective features are discussed.
Tracking array deformations using segmented least squares
Authors: Sarkar Kanad , Choi Jae Won , Mittal Manan , Corey Ryan M. , Singer Andrew C.
Published: April 2023

Recording on moving devices leads to constant deformations in microphone array structure, which interferes with spatial audio processing. Previously, we have established that there is a locally linear mapping between the manifolds of relative transfer functions (RTF) and array geometries. This mapping also applies to trajectories of array deformations and their corresponding RTFs. We run segmented least squares (SLS) on the RTF trajectories to discern potential states of motion in an unsupervised manner. We then examine an implementation of SLS for adaptive beamforming in a deformable setting.
Uncertainty quantification of deep learning based direction-of-arrival estimation with conformal prediction
Authors: Khurjekar Ishan D. , Gerstoft Peter
Published: April 2023

Direction-of-arrival (DOA) estimation is an important task in array signal processing with applications in underwater acoustics, biomedicine, geophysics, and robotics. The signals recorded on a spatially distributed array along with an analytical model of wave propagation, are used to estimate the unknown DOA. Recently, end-to-end deep learning-based methods have been proposed for improving DOA estimation performance. Yet, real-time DOA estimation has a number of challenges such as sensor noise, reverberant surroundings, uncertainty in sensor locations and environment. In this work, we propose to use conformal prediction for uncertainty quantification in DOA estimation. Conformal prediction is a statistically rigorous method to provide confidence intervals for an estimated quantity without making distributional assumptions. With conformal prediction, confidence intervals are computed via quantiles of user-defined score values. This easy-to-use method can be applied to any trained classification/regression model as long as an appropriate score function is chosen. The proposed approach shows potential to enhance the real-time applicability of deep learning methods for DOA estimation. We illustrate the advantages of conformal prediction for different deep-learning methods for DOA estimation. To the best of our knowledge, this is the first analysis of using conformal prediction for uncertainty quantification of deep learning methods for acoustic estimation.
Physics-based acoustic inversion of sound velocity and attenuation in low-velocity marine sediments
Authors: Zhou Ji-Xun , Li Zhenglin , zhang xuezhen , Qin Jixing
Published: April 2023

Using data from the Yellow Sea, arrival times of the direct wave and surface/bottom reflections from explosive sources to a vertical hydrophone array are used to precisely determine each explosive source’s location, the source energy spectral density (SESD), and the water depth. Long-range propagation waveforms reveal modal dispersion: the ground wave, water wave, Airy phase, etc. There are two high-frequency (HF) groups of water waves. One propagates with the sound speed in the water below the thermocline, the other with a speed close to the sound speed in the water above the thermocline. The HF group arrival times offer a time reference for dispersion analyses, including the ground wave speed at the cutoff frequency and the group velocity at Airy frequency. Associated with a top layer oflow-velocity sediments (LVS), seafloor reflections have two pulses: one from the water-sediment interface, one from the sediment-basement interface; Long-range transmission loss (TL) exhibits abnormal peaks at selected frequencies. Above-mentioned physics characteristics and the SESD-normalized TL(r) and TL(f) in 50–5000 Hz range up to 27.6 km are used for observationally driven inferences of seafloor geo-acoustic parameters, such as the sound velocity and attenuation in the LVS layer, its thickness, the sound velocity in the basement, etc.
A granular physics-based model for sediment dispersion
Authors: Clark Abe , Olson Derek , Swartz Andrew , Phua Sobing
Published: April 2023

Current models of dispersion in marine sediments include losses due to fluid viscosity and shearing at grain-grain contacts. An additional loss mechanism, which is well established in granular physics but is not included in existing models, is the inelasticity of normal compression at grain-grain contacts. Additionally, force-bearing contact networks, often called “force chains,” involve primarily normal compressive forces. These “force chains” are known to play a dominant role in force transmission in granular materials, including wave propagation. Using theoretical analysis of a 1D model “force chain” as well as DEM simulations in higher spatial dimension, we show that this granular mechanics perspective, where forces are transmitted along lossy force chains, may be able to explain salient features of the acoustic properties of marine sediments. In particular, the low and high-frequency behavior of the attenuation coefficient match a large collection of experimental data. [This was supported by the Office of Naval Research.]
Clinical research in acoustics: Reflections on a journey from bench to bedside and back again
Authors: Gallun Frederick J.
Published: April 2023

Thirty years ago, the author entered the field of acoustical research, curious as to how the human mind processes music. That search quickly led to the field of psychoacoustics and explorations of how basic sound elements are processed, which was presented at an ASA meeting in 1996. In 1999, the author had a benign tumor removed from his auditory nerve, leaving him deaf in his right ear. Over the next few years this led to his increasing interest in how people with altered hearing process sound. This presentation will describe the journey into clinical research that resulted, the amazing collaborative community that exists in hearing research, both on the clinical and basic sides, and how important it is to form connections among researchers and clinicians in order to fully explore the questions of how humans understand sound.
Classroom acoustics: Bridging the gap between standards and application
Authors: van Reenen Coralie , Manley David
Published: April 2023

Many countries have developed standards to regulate the acoustic conditions in classrooms. Most standards agree that the ideal ambient noise level should be between 30 and 40 dB, a reverberation time of 0.4 to 0.7 s, depending on the age and specific needs of the students and the type of activities taking place. Some standards include noise transmission levels to reduce unwanted noise transfer between adjacent spaces. Despite these standards, studies continue to show that many classrooms do not have acoustic qualities that are conducive to good learning outcomes. In most counties, the acoustic standards are not compulsory standards and good classroom acoustics is treated as a “nice to have” rather than as a key to good learning outcomes. This paper provides an overview of the classroom acoustics standards in several countries across the globe, considering how widely the standards are applied and identifying key concerns or gaps in implementation. The objective is to seek examples of successful implementation of standards, whether compulsory or voluntary, and to recommend mechanisms or interventions that could support the uptake and mainstreaming of good acoustic design for classrooms.
Classroom design, the architect, and teachers perspectives
Authors: Schutte Vanessa , Denison Dr. Marilyn
Published: April 2023

How do we design classrooms? The use and needs of modern learning environments have changed dramatically compared to the classrooms of 40 years ago. The fundamental reconsideration of the classroom environment is a direct result of teachers, school administrators, and architects coming to the realization that we all learn differently. The modern classroom is not just about four walls, it is about bringing diverse groups together. The ability to adapt to a variety of activities that support diverse learning styles is critical to today’s learning environments. Research proves that the design of a learning environment can have a negative or a positive impact on a student’s learning progress. We must understand how to design not only a simple classroom, but a suite of spaces that serve all student needs throughout the day. This presentations reviews the modern process and approach to classroom design from a broad-use perspective.
Classroom mock-up meeting Standard S12.60
Authors: Lind Stephen J.
Published: April 2023

The Acoustical Society of America (ASA) developed a standard entitled Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools (ASA/ANSI S12.60-2010) that provides a minimum set of requirements to help school planners and designers “provide good acoustical characteristics for classrooms and other learning spaces in which speech communication is an important part of the learning process.” In this revision, several details were revised for incorporation into building codes. Despite the obvious benefits of quieter classrooms, incorporating the standard into building codes met with resistance. A common perception was that in order to meet the standard’s requirements, specialized HVAC equipment and installation methods would be necessary, resulting in an installed cost beyond what most schools could afford. Acoustical prediction tools indicated that the requirements could be met using standard HVAC equipment and installation methods. To verify the predictions, a simulated classroom was built and several common types of equipment including a single-zone air handling unit, a high-efficiency water-source heat pump, and a packaged rooftop unit were tested. The selected products were standard catalog offerings, without any special attenuation features, that were operated at typical airflow and static pressures. This paper describes those tests, the conclusion, and the resulting recommendations.
Sound Transmission Guidelines in Mass Timber Schools; Meeting ASA/ANSI S12.60-2010
Authors: Callaghan Aedan
Published: April 2023

In recent years, the education sector has begun to turn to mass timber for new construction and expansions of schools. There are several reasons that make mass timber well suited for the education sector with seismic resistance and faster construction timelines being two major drivers. ANSI/ ASA S12.6 Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools is often used as the standard for school design and adequately addressing sound transmission between learning spaces. This analysis looks at mass timber assemblies that meet the ANSI/ ASA S12.60 guidelines. ASTM E336 and ASTM E1007 testing post construction was completed to evaluate in situ performance for comparison to the design guidelines.
The Italian standard on classroom acoustics UNI 11532-2:2020 explained through case studies
Authors: D'Orazio Dario
Published: April 2023

The UNI 11532-2:2020 is the Italian standard for acoustic environments in schools, comprised of classrooms and ancillary locals like libraries, gyms and canteens. Two years after its release, this talk is aimed to present some early results based on case studies, both on design simulations and in situ measurements. Indeed, on the one hand, the UNI 11532-2:2020 takes care of active classrooms asking consultants to consider the acoustic absorption of occupancy to reach the target range of reverberation time in a wide frequency range. It was shown how mixing material typologies becomes crucial to reach these targets. On the other hand, adequate intelligibility is needed in unoccupied conditions too. It showed how the requirements could be reached in small and large environments. A selection of case studies—a primary classroom, a library, and a university lecture hall—aims to show some design solutions to solve issues needed by the UNI 11532-2:2020.
The benefits and challenges of the collaborative for high performing schools acoustical performance requirements in Colorado K–12 schools
Authors: Whitney Matthew , Hanna Kristin
Published: April 2023

The Collaborative for High Performing Schools (CHPS) is a national organization that provides technical resources for school design, construction, operations, and maintenance standards. It also provides a verification program, which includes an acoustical performance prerequisite and enhanced acoustical performance credits. This presentation will explore the benefits and challenges of the various acoustical prerequisite and credit requirements, including reverberation time (RT) targets, background noise criteria, and interior and exterior sound isolation, through the design and construction of several projects in Colorado. By comparing the theoretical benefits to the practical applications of these requirements, improvements to constructibility are proposed. Additionally, the financial impact of pursuing a CHPS certification is examined, especially for school districts with limited financial resources.
Listening in complex acoustic scenarios: Ongoing advances on methodologies and approaches in relation to classrooms
Authors: Puglisi Giuseppina E. , Astolfi Arianna , Warzybok Anna
Published: April 2023

The acoustic quality of the built environment where we spend our days strongly affects our social life and indirectly our health. Particularly, people with a hearing impairment (usually related to ageing), children with or without learning disorders and non-native speakers, require better room acoustics to enhance speech communication and be included in the challenging multicultural processes. In the specific framework of children in their everyday learning environments, i.e., in classrooms, enhanced speech intelligibility (SI) is necessary. Noise and reverberation in classrooms degrade SI, but the combined effect of reverberation, informational noise and position of target, listener and noise source on SI still needs insights. This work provides an overview on the recent research carried out in the field of SI under complex acoustic scenarios. Results from in-field measurements as well as from advanced predictive models will be presented and discussed. Particularly, measurements were integrated with listening tests based on the Matrix material, since it has been optimized for the Italian language and for many other foreign languages. Concerning the predictions’ results, the Binaural Speech Intelligibility Model (BSIM) implemented at the University of Oldenburg was used to validate an accurate method to predict the listeners’ ability at the classroom’s design stage.
Sound propagation and strength in small classrooms
Authors: Astolfi Arianna , Puglisi Giuseppina E. , Minelli Greta
Published: April 2023

The study involved 29 occupied primary-school classrooms in Italy where speech level (LS) and Sound Strength total (Gtot), early (G50) and late (Glate), have been acquired at 1 m from the source and in other three positions along the main axis of the room. The background noise level during the measurements was less than 56 dB(A) and the reverberation time (RT) was between 0.5 s and 1.4 s. A cut-off value of RT was assumed equal to 0.8 s for subdividing the classrooms in two groups of similar size, with lower or equal and higher RT values, respectively. The slopes per double distance of the speech level along the axis, mLS, is −2 dB/dd for both the groups. The same slope per double distance is obtained for G50 of −2.7 dB/dd, while Glate shows a slope of −0.6 dB/dd and −0.9 dB/dd for the two groups, respectively. The slope per double distance of Gtot is −2.0 dB/dd as in the case of the speech level, mLs, as expected. Optimal reverberation time range, between 0.6 s and 0.9 s, in occupied conditions, has been obtained from the difference Glate-G50 at the rear positions between 6 and 3 dB, respectively.
Age effect on students’ intelligibility listening to a teacher with a dysphonic voice
Authors: Bottalico Pasquale , Murgia Silvia , Flaherty Mary M.
Published: April 2023

The purpose of this project is to assess the acoustical conditions in which optimal intelligibility and low listening effort can be achieved in real classrooms for elementary students, taking into consideration the effects of dysphonic voice and typical classroom noise. Speech intelligibility tests were performed in classrooms with 80 normal-hearing students (7–11 years old). The speech material was produced by a female actor using a normal voice quality and simulating a dysphonic voice. The stimuli were played by a Head and Torso Simulator. Child babble noise and classrooms with different reverberation times were used to obtain a Speech Transmission Index range from 0.2 to 0.7. The results showed a significant decrease in intelligibility when the speaker was dysphonic, in STI higher than 0.33. The rating of listening difficulty showed a significantly greater effort in perceiving the dysphonic voice. Younger children showed poorer performance and greater listening difficulty compared to older children when listening to the normal voice quality. Both groups were equally impacted when the voice was dysphonic. The results suggested that better acoustic conditions are needed for children to reach a good level of intelligibility and to reduce listening effort if the teacher is suffering from voice problems.
Cognitive perception of biosonar echo delay, phase, and spectrum
Authors: Simmons James A. , Simmons Andrea M.
Published: April 2023

FM echolocating big brown bats combine the acoustic delay, phase, and spectrum of echoes into a unitary cognitive attribute of perceived delay. In this talk, we will present psychophysical, neurophysiological, and modeling data showing how this might be accomplished. Delay accuracy measured psychophysically approximates coherent matched-filter accuracy. Psychophysical curves of echo-delay resemble pulse-echo crosscorrelation functions, with phase manifested directly within 20 μs. Computational modeling shows that low-pass time-frequency bandpass filtering at 10 kHz enables the contribution from phase. Neural responses from the auditory midbrain are phase-sensitive for tone-burst offsets up to15 kHz. Echo spectrum (spectral nulls and ripples) is transformed into psychophysical percepts of delay. The external-ear spectral null creates an elevation-dependent peak at about 35 μs for vertical target tracking. Off-axis clutter masking is suppressed by a Gestalt-like normalization process that operates within delay percepts. The organization of perceived delay and the appearance of phase shifts is facilitated by delay processing that begins at the low-frequency tail end of FM sweeps and the linking of 1st and 2nd harmonic frequencies. Surprisingly, this result requires the entire echo to be received before any delay is determined. The implications of this result will be discussed. [Work supported by ONR.]
“Let's see what happens!”—His words were and still are guiding me
Authors: Hiryu Shizuko
Published: April 2023

The first paper I read when I started studying bats as a student was Jim's paper. At the time, I never dreamed that a few years later we would be able to conduct bat experiments together in Japan and the United States. Although it was my first and last study abroad experience, and it was only for a month, the experience of working with Jim every day guided my confidence and career path as a researcher. I will never forget the excitement when we conducted a flight experiment using a telemetry microphone together and found that the big brown bats were fluctuating the pulse frequency up and down in a cluttered environment. This experience sparked my interest in the jamming avoidance behavior of bats, which has become a very important research topic for me. I have been very fortunate to have had the opportunity to see up close the ideas that come from his vast experience and knowledge and to witness the respectful attitude he has toward bats and nature as a pure researcher. Jim is a great researcher whom I genuinely admire and who taught me to enjoy bats, nature, and research indeed.
Specializations of bat auditory cortex for processing echoes arriving at different delays
Authors: Smotherman Michael , Macias Silvio
Published: April 2023

The bat auditory system follows the standard mammalian plan, but many specializations have been uncovered that appear uniquely tailored to support echolocation. However, it still remains uncertain which, if any, neurophysiological specializations are truly unique to echolocation. The question is important because it defines the extent to which bats may serve as general models of auditory processing, and it points towards which elements are critical for biosonar processing. One of their most unique neurophysiological features is the presence of neurons sensitive to the time delay between the outgoing pulse and returning echo. These delay-tuned neurons are found in the auditory cortex of all bats, but their neuroanatomical distribution is distinctly different in FM-type bats compared to CF-type and neotropical fruit bats. In FM bats, delay-tuned neurons are sprinkled throughout primary auditory cortex rather than comprising their own auditory subfield, suggesting they might do more than just target ranging. We hypothesized that delay-tuned neurons might dynamically modulate the neural substrate to match changing pulse acoustics for targets at different distances. Results supported the hypothesis by showing that activation of delay-tuned neurons was directly correlated with concomitant changes in the frequency tuning properties of nearby neighboring neurons.
Bats to belugas: Functional anatomy of air versus water biosonar
Authors: Ketten Darlene R. , Simmons Andrea M. , Simmons James A.
Published: April 2023

Acoustic task similarities of odontocetes (toothed whales) and microchiropterans (insectivorous bats) suggest they have common biosonar mechanisms. However, media differences; e.g., sound speeds in air versus water, may have driven variations in auditory system adaptations. We examined the peripheral auditory system of an FM bat (big brown bat Eptesicus fuscus) and two toothed whale species (harbor porpoise Phocoena phocoena; bottlenose dolphin Tursiops truncatu) using ultra high resolution (11 μm) isotropic voxel microCT. Significant differences were found among species for oval window location, cochlear length, basilar membrane gradients, cochlear spiral morphometry, cochlear curvature, and basilar membrane stiffness. High and low frequency hearing range cut-offs correlate with basilar membrane thickness/width ratios and cochlear radii of curvature. These features predict species specific high and low frequency hearing limits. Harbor porpoises, the highest frequency echolocator in the study, have large basal basilar membrane ratios and a “foveal” region with a constant membrane ratio similar to those reported for some bat species, consistent with a “stretched” frequency region. Furthermore, both the bats and harbor porpoises examined displayed unusual stapedial input locations and tightly coiled cochleae, specializations that may enhance ultrasonic frequency signal resolution and diminish low frequency cochlear propagation.
Midbrain inactivation produces sonar navigation deficits in the echolocating bat, Eptesicus fuscus
Authors: Diebold Clarice A. , Allen Kathryne , Lawlor Jennifer , Moss Cynthia F.
Published: April 2023

The contribution of different brain structures to auditory-guided behaviors in echolocating bats is not fully understood. Historically, area-specific inactivation studies have provided insights into the function of brain regions; however, lesioning is permanent and can cause incidental damage to non-target areas, which can compromise the interpretation of behavioral effects. We have established the use of Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) to reversibly inactivate excitatory neurons in the midbrain of the insectivorous bat, Eptesicus fuscus. We targeted the inferior and superior colliculi, two structures implicated in processing returning echoes and coordinating motor responses, including the production of sonar vocalizations. After bilateral infusions in either the IC or SC, bats were trained to fly down a corridor and navigate through an opening in a partition to receive a food reward. Midbrain inactivation dramatically altered performance in the behavioral task. Bats with IC inactivation showed reduced precision in steering through the partition opening, as well as changes in echolocation calls. SC inactivation produced a profound deterioration of the bat's behavior, with the bat unable to fly down the corridor. Our preliminary results open the door to many potential applications of DREADDs to uncover the neural mechanisms supporting navigation through echolocation.
Echolocating bats dynamically regulate hearing sensitivity: Behavioral and physiological evidence
Authors: Ye Huan , Luo Jinhong
Published: April 2023

James Simmons's previous study on automatic gain control in the big brown bat has suggested the contractions of middle-ear muscle and forward masking impairing hearing sensitivity during vocalization. The influence of vocal production can be extremely severe for bat species that produce constant-frequency (CF) sonar signals. However, perceptual hearing sensitivity and the underlying mechanisms in CF bats remain virtually unexplored. In this work, combing a 2-AFC psychophysical setup and an electrophysiological setup, we measured the hearing sensitivity of a CF bat, Hipposideros pratti, either in a passive listening (PL) task to detect pure tones, an active listening (AL) task to detect pure tones triggered by its vocalization, or a phantom Echo task. Behavioral data show that H. pratti had the best hearing sensitivity of approximately 0 dB SPL in the PL task, but nearly 40 dB worse in the Echo task. In the AL task, all bats gradually increased call frequency by 0.8 to 1.1 kHz to overcome self-generated auditory masking. Preliminary neurophysiological data indicate that the neural responses in the midbrain inferior colliculus can be highly plastic. Together, our data suggest that echolocating bats dynamically control the hearing sensitivity during vocalization in a complex manner.
Listening to the raindrops from underwater for weather and climate
Authors: Ma Barry B.
Published: April 2023

Jeffrey A. Nystuen is a pioneer in using the passive acoustic method to measure oceanic rainfall. Under Nystuen’s efforts, a self-contained passive acoustic recording device called the acoustic rain gauges were deployed all over the world, from a brackish pond in Florida, Carr inlet in Puget Sound, Crater Lake in Oregon, BioSphere II in Arizona, then to the South China Sea, the Pacific Ocean, the Taiwan strait, the Ionian Sea in Greece, the Aleutian Islands and ocean station Papa. This simple device records long-term spectra of sound pressure levels with minimum data screening, could detect the presence of oceanic rainfall, and provide estimates of rain rate and surface wind speed. Nystuen’s inspirational works over the past three decades set an example and path for future scientists and engineers to foster curiosity, pursue exploration and make discoveries.
Early ocean ambient sound monitoring, precursor to soundscapes today, influenced by J. Nystuen
Authors: Howe Bruce M. , Andrew Rex
Published: April 2023

In the early 1990s, as the Acoustic Thermometry of Ocean Climate (ATOC) program was starting, simple statistics of ocean ambient sound were unknown. For instance, what fraction of time does the sound level at some frequency exceed a certain value? When the Cold War ended, US Navy SOSUS arrays became available for “dual use” science. At the Applied Physics Laboratory, University of Washington, we began to collect ambient sound data in 1994 from Navy arrays in the Pacific. Initial data spanning 2 years were presented by Curtis et al. [JASA (1999)]. Data and corresponding analyses were separated according to process, i.e., shipping, marine mammals, and wind, as well as for the total. This monitoring effort continued for nearly two decades as reported by Andrew et al. [JASA (2011)], with other collaborators involved (Metzger and Mercer). Throughout, J. Nystuen was always providing guidance and advice in the data analysis and interpretation of the ambient sound data, in fact influencing the first author as graduate students together. We review these early results and connect them to present day understanding and data collection efforts that reflect the status of Ocean Sound as an Essential Ocean Variable of the Global Ocean Observing System.
Sperm whale acoustic ecology investigations using Jeffrey Nystuen‘s Passive Aquatic Listeners
Authors: Diogou Nikoletta , Palacios Daniel , Katsanevakis Stylianos , Klinck Holger
Published: April 2023

When Jeffrey Nystuen invented the Passive Aquatic Listener (PAL) for quantifying rainfall and wind speed using underwater sound spectra, he considered all biological sounds in the recordings as noise. Using this noise data, I built a doctoral thesis, comprised of three published papers. None of this would have happened without Jeff’s continuous encouragement and support. Here, we present results from analyzing (1) five years (2007–2012) of PAL recordings from Ocean Station PAPA (OSP) in the offshore Gulf of Alaska; and (2) 19 months of PAL data from two sites, Pylos and Athos Stations (in the Hellenic Trench and North Aegean Trough respectively), in the Greek Seas, investigating the acoustic ecology of sperm whales (Physeter macrocephalus). Results of the bioacoustic analysis revealed the year-round presence of sperm whales at OSP and the Ionian Sea, with higher detections during the warm seasons. The sperm whale time series from OSP was correlated with in situ and remotely-sensed oceanographic variables to improve our understanding of global-warming-driven changes in the pelagic ecosystem of the NE Subarctic Pacific. Results from the Hellenic Trench emphasize the risk from increased shipping noise and contribute to the conservation efforts for the small, endangered sperm whale population in an understudied region.
Gene and drug delivery using ultrasound-targeted microbubble cavitation
Authors: Villanueva Flordeliza S.
Published: April 2023

Therapeutic delivery of oligonucleotides, such as RNAs, has the potential to treat heretofore “undruggable” targets in diseases such as cancer. However, systemic intravascular delivery of RNAs to tumor tissue is limited by the vascular endothelium, which provides a barrier to transendothelial passage of large, charged molecules. To address RNA delivery challenges, we and others have developed an approach employing ultrasound targeted microbubble cavitation (UTMC), which utilizes 2–4 μm diameter gas-filled microbubbles that carry RNA on the shell and also serve as an ultrasound imaging agent. As intravenously injected microbubbles travel through the microcirculation, localized ultrasound induces microbubble cavitation, causing localized payload release from the microbubble. In addition to delivering the RNA payload, UTMC increases endothelial permeability, thus increasing local extravasation of the payload, while sparing non-insonified tissue (reduced off-target effects). Microbubbles are non-immunogenic and protect loaded RNA against nuclease digestion. Because UTMC concentrates the RNA at the tumor site, lower systemic RNA doses can be used, resulting in fewer off-target effects. A unique feature is that the microbubble that carries and releases the RNA also permits simultaneous US imaging of microbubble location. This lecture will review these unique features of UTMC for drug delivery and current work in this area.
Combining stimuli-responsive colloids and focused ultrasound for drug delivery
Authors: Porter Tyrone M.
Published: April 2023

Over the years my research group has engineered colloids that respond to changes in pressure or temperature locally induced by focused ultrasound. We designed thermosensitive liposomes that released small or large molecular cargo rapidly when heated above normal body temperature by only a few degrees. Potentially, these liposomes can be combined with MR-guided focused ultrasound for noninvasive and image-guided triggered drug delivery. Separately, we developed liquid perfluorocarbon nanoemulsions that can be vaporized with high amplitude acoustic pulses. The resultant bubbles can then be used to facilitate cavitation-mediated permeation of biological interfaces, including cell membranes and the blood-brain barrier. This presentation will review some of our key observations and will discuss the potential for translating these technologies.
Modeling coupled oscillators: Applications for musical sequencing and synthesis
Authors: Sibley-Schwartz Jazer G.
Published: April 2023

There are many naturally occurring systems of coupled oscillators, e.g., the synchronization of firefly flashes, frog calls, and electrical impulses in the brain. The behavior of a large system of coupled oscillators can be approximated using the Kuramoto-Daido model. The model shows that phase calculations for each oscillator can be simplified by comparing each oscillator’s phase to the average phase of the collection, eliminating the need to sum over the whole group. In this session, we will explore this algorithm in Max/MSP. We will look at simple systems with a small number of low frequency oscillators, both free-running and rhythmically quantized/Euclidean, as a means of generating rhythmic patterns and sequences. Then we will look at larger collections of oscillators within the audible frequency range and explore how the algorithm can be used to modulate audio signals for timbral effects. This example will delve into how the coupling algorithm affects oscillators that have frequency relationships drawing from the overtone series. We will also see how delaying the averaged signal simulates a proximity effect that more closely resembles the localized synchronization that occurs in natural systems.
Observation of torsion on bowed strings
Authors: Mores Robert
Published: April 2023

Research on bowed string motion focuses on transverse waves and not so much on torsional waves. These are believed to play only a minor role for stabilizing vibrations and no role for perception. Here, torsion is measured on both sides of the bow contact point for a variety of bridge-bow distances on a cello string. Electromagnetical and optical measurements correspond. Every periodic string release is preceded by a reverse torsional motion independent from bowing position or dynamics. Transverse and torsional motions are coupled and there are cases of stabilization, but also cases of perturbation or surrender. Structural and timing analyses of torsional waves suggest that the earlier concepts of differential slipping can be essentially confirmed. Other concepts cannot be confirmed, such as the Schelleng ripples, or are under question, such as the concept of subharmonics.
Urban soundscape studies via soundwalks in Nashville
Authors: Woolworth David S. , Brooks Bennett M.
Published: April 2023

Soundscape studies were conducted in Nashville, Tennessee in conjunction with the Acoustical Society fall meeting in 2022. Nashville is a growing city known for its musical entertainment district (Broadway), which post-pandemic attracts numerous tourists year round. It also has other nearby surrounding areas which support many businesses and residences. Both the entertainment district and its surrounding areas were the focus of this study. Three pre-soundwalk acoustical tests were conducted during site surveys to determine the soundwalk path and data collection locations. In December 2022, a soundwalk was conducted to collect participant perception data in accordance with ISO 12913 methods. The results of the physical sound measurements and the soundwalk perception data will be discussed. The effect of transient events on the sound environment are evaluated. In addition, potential interventions to improve existing conditions are proposed
Road traffic noise informational masking with water sound sequences: From laboratory simulation to field study
Authors: Li Jian , Maffei Luigi , Pascale Aniello , Masullo Massimiliano , Lin Minqi , Chau Chi-Kwan
Published: April 2023

Road traffic noise control in urban green space is a big concern for urban designers and public managers. The introduction of water sounds into noisy environment has been proven effective based on the soundscape approach. To extend more effective and applicable strategies for water sound informational masking, the exploration of the spatial settings of virtual water sound playbacks in urban parks were conducted both in the laboratory and field settings. Three different spatial water-sound sequences were added into the virtual noisy environment through an immersive spatial audio system and the real urban green park through the digital audio programming of bluetooth loudspeakers. The mental activities and subjective feelings of two group subjects were evaluated by a portable electroencephalogram (EEG) measurement with a post-doc questionnaire. The better masking effects introduced by the spatial settings of water sounds had been confirmed from the results of more positive emotional feedbacks and more relaxed mental state revealed by the spectral power of alpha band across two experimental conditions. Especially, the two-position switching water sounds brought more attentional network activations. Moreover, more sensory accumulation effects reflected by the mental network activations were observed from the brain activities in the in situ measurement compared to laboratory-setting.
The effect of stress and saturation on low-frequency nonlinear elasticity in geological materials
Authors: Lisabeth Harrison
Published: April 2023

Wave propagation in rocks is typically treated in seismology as a purely linear elastic phenomenon; however, evidence for nonlinear elastic behavior in geomaterials has existed for years. The degree of nonlinearity in fractured material is much greater than that in intact material, resulting in signals that are highly sensitive to the state of the fracture (stress, chemistry, fluids). Elastic nonlinearity can cause a propagating wave to distort, resulting in generation of harmonics and multiplication of waves of different frequencies. One way to exploit these behaviors is to propagate waves of differing frequencies through a material and observe nonlinear wave mixing phenomena, a technique referred to in the literature as nonlinear wave modulation spectroscopy (NWMS). I will discuss the use of NWMS for the study of geologic materials at a range of conditions to highlight the frequency, stress, and fluid dependence of nonlinear parameters in rocks. Analysis of various dependencies can provide insight into the mechanisms of nonlinearity and has the potential to provide methods of monitoring the dynamic state of the subsurface.
Prediction of acoustical behavior of granular material stacks as measured in a standing wave tube by using a Biot theory-based model
Authors: Mo Zhuang , Song Guochenhao , Shi Tongyang , Bolton J. S.
Published: April 2023

The acoustical behavior of granular materials, such as activated carbon and silica gel, has drawn attention in recent studies, due to their favorable properties such as good low frequency sound absorption. Like other more traditional porous materials, granular materials can also be tested in a standing wave tube for a convenient assessment of their acoustical properties. However, the behavior of granular materials stacked in a standing tube is more complex than that of traditional materials. For example, the response of lightweight glass bubbles reveals a clear dependence on the sound pressure level of the input signal. Also, when tested in standing wave tubes of different diameters, the same type of granular materials displays differences in their behavior. The apparent stiffness of granule pack is also related to the depth of the stack. In the present work, a model based on Biot theory is proposed, together with a consideration of the effect of the change of boundary conditions and the granule stack stiffness in different test configurations. The model is realized by using a finite difference method, and the simulation results are compared with measurements of different types of granular materials.
Investigation of ultrasound propagation through dense glass bead packings immersed in water
Authors: Le Ber Arthur , Lépicier Damien , Aubry Alexandre , Tourin Arnaud , Jia Xiaoping
Published: April 2023

Conventional ultrasound imaging generally relies on a single scattering assumption and a constant sound hypothesis. However, in dense granular sediments where the glass beads diameter is comparable to the wavelength (typically 500 μm), both hypothesizes are no longer valid, resulting in a loss of resolution and contrast, up to the situation where a target to image could totally vanish in the fog. To better characterize this strongly scattering medium, we have conducted several ultrasonic experiments in reflection and in transmission, either on the diffused wave or on the coherent one. Both the transport and scattering mean free paths are estimated in the imaging bandwidth (1–5 MHz), alongside with the phase velocity and extinction length of the coherent wave. These results are compared with an analytical model, i.e. Generalized Coherent Potential Approximation*, which considers a coated sphere buried in an effective medium. Finally, we show a dispersive beamformer which takes into account the measured phase and group velocity. This allows us to obtain a more resolved and contrasted image in such a scattering medium. * Jing X, Sheng P, Zhou M. Phys Rev Lett. 1991