bluuebunny/crossref_metadata_2025 huggingface dataset:
Organ‐specific symptom patterns during oral food challenge in children with peanut and tree nut allergy
Authors: Dobbertin‐Welsch Josefine , Staudacher Olga , Yürek Songül , Trendelenburg Valérie , Tschirner Sebastian , Ziegert Mandy , Ahrens Frank , Millner‐Uhlemann Martina , Büsing Susanne , Striegel Anne , Ott Hagen , Arens Alisa , Gappa Monica , Lange Lars , Gernert Sunhild , Niggemann Bodo , Beyer Kirsten
Published: May 2022

Background

Peanut and tree nut allergies are common in childhood and often severe in nature. The clinical picture shows a wide variety of symptoms.

Objective

To analyze the distribution of clinical symptoms and severity during oral food challenges (OFC) in children.

Methods

Analysis of 1.013 prospectively recorded, positive OFCs with peanut (n = 607), hazelnut (n = 266), walnut (n = 97), and cashew (n = 43). Symptoms were categorized as immediate‐type skin, gastrointestinal, upper and lower respiratory, cardiovascular symptoms, and eczema exacerbation. Symptom severity and treatment were recorded.

Results

Skin symptoms presented in 78%, followed by gastrointestinal (47%), upper (42%), and lower respiratory symptoms (32%). Cardiovascular symptoms presented in 6%. In three‐quarter of the reactions, more than one organ was involved. Importantly, severe reactions occurred at every dose level. Peanut‐ and cashew‐allergic patients had a higher relative risk of gastrointestinal symptoms compared with hazelnut‐ and walnut‐allergic patients. Patients without vomiting had a 1.7 times higher risk developing immediate‐type skin and/or lower respiratory symptoms. Three‐quarter of the patients ever had eczema but worsening presented in only 10.5% of the OFCs. In patients with multiple food allergies, organs involved, eliciting dose and severity differed between allergens.

Conclusion

Although comparisons between allergen groups with different clinical history, severity, comorbidities and laboratory data are difficult and might contain bias, our data confirm the high allergenic potential of peanut and tree nuts. The rare occurrence of eczema worsening emphasizes that avoidance diets of peanuts and tree nuts to cure eczema seem to be unnecessary and may hamper tolerance maintenance.
3D Browsing of Wide‐Angle Fisheye Images Under View‐Dependent Perspective Correction
Authors: Huang Mingyi , Wu Jun , Peng Zhiyong , Zhao Xuemei , Xu Gang
Published: May 2022

This paper presents a novel technique for 3D browsing of wide‐angle fisheye images using view‐dependent perspective correction (VDPC). First, the fisheye imaging model with interior orientation parameters (IOPs) is established. Thereafter, a VDPC model for wide‐angle fisheye images is proposed that adaptively selects correction planes for different areas of the image format. Finally, the wide‐angle fisheye image is re‐projected to obtain the visual effect of browsing in hemispherical space, using the VDPC model and IOPs of the fisheye camera calibrated using the ideal projection ellipse constraint. The proposed technique is tested on several downloaded internet images with unknown IOPs. Results show that the proposed VDPC model achieves a more uniform perspective correction of fisheye images in different areas, and preserves the detailed information with greater flexibility compared with the traditional perspective projection conversion (PPC) technique. The proposed algorithm generates a corrected image of 512 × 512 pixels resolution at a speed of 58 fps when run on a pure central processing unit (CPU) processor. With an ordinary graphics processing unit (GPU) processor, a corrected image of 1024 × 1024 pixels resolution can be generated at 60 fps. Therefore, smooth 3D visualisation of a fisheye image can be realised on a computer using the proposed algorithm, which may benefit applications such as panorama surveillance, robot navigation, etc.
Cognitive, psychological and social factors associated with older adults' mobility: a scoping review of self‐report and performance‐based measures
Authors: Kalu Michael E. , Bello‐Haas Vanina Dal , Griffin Meridith , Boamah Sheila , Harris Jocelyn , Zaide Mashal , Rayner Daniel , Khattab Nura , Abrahim Salma , Richardson Tristan K. , Savatteri Nicholas , Wang Yimo , Tkachyk Christian
Published: May 2022

Although many factors have been associated with mobility among older adults, there is paucity of research that explores the complexity of factors that influence mobility. This review aims to synthesise the available evidence for factors comprising the cognitive, psychological, and social mobility determinants and their associations with mobility self‐reported and performance‐based outcomes in older adults (60 years). We followed Arksey and O′Malley's five stages of a scoping review and searched PubMed, EMBASE, PsychINFO, Web of Science, AgeLine, Allied and Complementary Medicine Database, Cumulative Index to Nursing and Allied Health Literature and Sociological Abstract databases. Reviewers in pairs independently conducted title, abstract, full‐text screening and data extraction. We reported associations by analyses rather than articles because articles reported multiple associations for factors and several mobility outcomes. Associations were categorised as significantly positive, negative, or not significant. We included 183 peer‐reviewed articles published in 27 countries, most of which were cross‐sectional studies and conducted among community‐dwelling older adults. The 183 articles reported 630 analyses, of which 381 (60.5%) were significantly associated with mobility outcomes in the expected direction. For example, older adults with higher cognitive functioning such as better executive functioning had better mobility outcomes (e.g., faster gait speed), and those with poor psychological outcomes, such as depressive symptoms, or social outcomes such as reduced social network, had poorer mobility outcomes (e.g., slower gait speed) compared to their counterparts. Studies exploring the association between cognitive factors, personality (a psychological factor) and self‐reported mobility outcomes (e.g., walking for transportation or driving), and social factors and performance‐based mobility outcomes in older adults are limited. Understanding the additive relationships between cognitive, psychological, and social factors highlights the complexity of older adults' mobility across different forms of mobility, including independence, use of assistive devices, transportation, and driving.
Expanding the social psychological study of educators through humanizing principles
Authors: Destin Mesmin , Silverman David M. , Rogers Leoandra Onnie
Published: May 2022

The social psychological study of education contains growing potential to contribute to the understanding of learning and the design of effective learning environments that support youth development. As research on educators in particular expands, there are key insights and perspectives from areas outside of psychology that can help to guide the direction of new studies and approaches. Humanizing frameworks are especially well suited to inform the social psychological study of educators, as they address the ways that institutions deny the humanity of people from groups that face economic and ethnic‐racial marginalization in the United States. By following principles of humanization to evaluate, deepen, and broaden social psychological approaches, future research becomes more likely to advance knowledge in ways that embrace the inherent value of students as whole people. Identity‐based motivation theory provides an example of a social psychological approach expanding to emphasize the role of educators with attention to principles of humanization.
Genomic insights into recent species divergence in Nicotiana benthamiana and natural variation in Rdr1 gene controlling viral susceptibility
Authors: Cauz‐Santos Luiz A. , Dodsworth Steven , Samuel Rosabelle , Christenhusz Maarten J. M. , Patel Denise , Shittu Taiwo , Jakob Aljaž , Paun Ovidiu , Chase Mark W.
Published: May 2022

One of the most commonly encountered and frequently cited laboratory organisms worldwide is classified taxonomically as Nicotiana benthamiana (Solanaceae), an accession of which, typically referred to as LAB, is renowned for its unique susceptibility to a wide range of plant viruses and hence capacity to be transformed using a variety of methods. This susceptibility is the result of an insertion and consequent loss of function in the RNA‐dependent RNA polymerase 1 (Rdr1) gene. However, the origin and age of LAB and the evolution of N. benthamiana across its wide distribution in Australia remain relatively underexplored. Here, we have used multispecies coalescent methods on genome‐wide single nucleotide polymorphisms (SNPs) to assess species limits, phylogenetic relationships and divergence times within N. benthamiana. Our results show that the previous taxonomic concept of this species in fact comprises five geographically, morphologically and genetically distinct species, one of which includes LAB. We provide clear evidence that LAB is closely related to accessions collected further north in the Northern Territory; this species split much earlier, c. 1.1 million years ago, from their common ancestor than the other four in this clade and is morphologically the most distinctive. We also found that the Rdr1 gene insertion is variable among accessions from the northern portions of the Northern Territory. Furthermore, this long‐isolated species typically grows in sheltered sites in subtropical/tropical monsoon areas of northern Australia, contradicting the previously advanced hypothesis that this species is an extremophile that has traded viral resistance for precocious development.
Analytic Velocity Obstacle for Efficient Collision Avoidance Computation and a Comparison Study With Sampling and Optimization-Based Approaches
Authors: Xi Zhimin , Torkamani Elnaz Asghari
Published: May 2022

Velocity obstacle (VO) is one of the popular reactive navigation algorithms for the path planning of autonomous agents. The collision-free property can be guaranteed if the agent is able to choose a velocity outside the VO region under the assumption that obstacles maintain a constant velocity within the control cycle time of the agent. To date, the selection of the optimal velocity relies on either sampling or optimization approaches. The sampling approach can maintain the same amount of computation cost but may miss feasible solutions under collision risks with an insufficient number of samples. The optimization approach such as the linear programming demands convexity of the constraints in the velocity space which may not be satisfied considering non-holonomic agents. In addition, the algorithm has varying computation demands depending on the navigation situation. This paper proposes an analytic approach for choosing a candidate velocity rather than relying on sampling or optimization approaches. The analytic approach can significantly reduce computation costs without sacrificing performance. Agents with both holonomic and non-holonomic constraints are considered to demonstrate the performance and efficiency of the proposed approach. Extensive comparison studies with static, non-reactive, and reactive moving obstacles demonstrate that the analytical VO is computationally much more efficient than the optimization-based approach and performs better than the sampling-based approach. Major video results of this paper can be accessed online.
Atmospheric pressure plasma functionalization of polystyrene
Authors: Polito Jordyn , Denning Mark , Stewart Richard , Frost David , Kushner Mark J.
Published: May 2022

Atmospheric pressure plasma jets (APPJs) are used to improve the adhesive and hydrophilic properties of commodity hydrocarbon polymers such as polypropylene, polyethylene, and polystyrene (PS). These improvements largely result from adding oxygen functional groups to the surface. PS functionalization is of interest to produce high value biocompatible well-plates and dishes, which require precise control over surface properties. In this paper, we discuss results from a computational investigation of APPJ functionalization of PS surfaces using He/O2/H2O gas mixtures. A newly developed surface reaction mechanism for functionalization of PS upon exposure to these plasmas is discussed. A global plasma model operated in plug-flow mode was used to predict plasma-produced species fluxes onto the PS surface. A surface site balance model was used to predict oxygen-functionalization of the PS following exposure to the plasma and ambient air. We found that O-occupancy on the surface strongly correlates with the O-atom flux to the PS, with alcohol groups and cross-linked products making the largest contributors to total oxygen fraction. Free radical sites, such as alkoxy and peroxy, are quickly consumed in the post-plasma exposure to air through passivation and cross-linking. O-atom fluences approaching 1017 cm−2 saturate the O-occupancy on the PS surface, creating functionality that is not particularly sensitive to moderate changes in operating conditions.
R. BRUCE LINDSAY AWARD 2022: Meaghan A. O'Reilly
Authors: O'Reilly Meaghan A.
Published: May 2022

The R. Bruce Lindsay Award (formerly the Biennial Award) is presented in the Spring to a member of the Society who is no more than 10 years post terminal degree on 1 July at the time of Award acceptance and who, during a period of two or more years immediately preceding the award, has been active in the affairs of the Society and has contributed substantially, through published papers, to the advancement of theoretical or applied acoustics, or both. The award was presented biennially until 1986. It is now an annual award.
Exploration of ultrasound-mediated microbubble-cell membrane interactions using novel protein-loaded microbubbles and their role in immunomodulation
Authors: Brans Veerle A. , Gray Michael , Sezgin Erdinc , Stride Eleanor P.
Published: May 2022

The immune response is governed by the dynamic spatiotemporal regulation of signalling proteins at the interface between immune cells and their targets. The broadened knowledge of immunology and antitumour immune responses has led to the development of a novel cancer therapy avenue: immunotherapy. Elucidating the underlying mechanisms of immunotherapy is, however, crucial as in some patients, and it is accompanied by a characteristic toxicity profile and severe side effects such as autoimmune endocrinopathies. This requires quantitative investigation of cell-cell interactions, including the cell membrane receptors and their molecular behaviour upon cellular contact. This work applies a novel strategy employing protein-loaded microbubbles and confocal fluorescence microscopy to investigate cavitation-induced microbubble-cell membrane interactions. To this end, microbubbles functionalised with a model protein were successfully produced and characterised using nickelated lipids and His-tagged proteins as an efficient tagging strategy. These microbubbles form a novel platform for studying the impact of changing ultrasound parameters on the non-invasive delivery of these proteins to target cells, by means of transfer and/or fusion. This knowledge will be applied to explore efficient targeting strategies for custom-made functionalised bubbles to increase their visibility to immune cells.
Timbral effects the Paulstretch audio time-stretching algorithm
Authors: Malloy Colin
Published: May 2022

The Paulstretch algorithm is a procedure for achieving aurally pleasing extreme time-stretches while avoiding the “phasiness” issues common to phase-vocoder-based implementations. The algorithm accomplishes this by randomizing the phase information where a typical phase-vocoder approach would perform phase-unwrapping or another method to preserve phase alignment. When performed without time-stretching, phase randomization is often referred to as whisperization. This allows for more extreme time-stretches than other approaches. Where most audio time-stretching is usually used for small adjustments, Paulstretch is regularly used to stretch audio by a factor of 5, 10, 20 or much more. This effect is popular for its aesthetic timbral effects and is regularly used in soundscapes, film/television scoring, and more. When time-stretching is performed at such extremes, however, it is unclear how randomizing the phase, different FFT window sizes, the stretch factor, and other variables combine to affect the reconstructed audio output. This study employs multiple audio analysis methods to examine the spectral, timbral, and perceptual effects of the Paulstretch algorithm.
Wind, sea swell, and excitation of atmospheric waveguides by underwater earthquakes
Authors: Godin Oleg A.
Published: May 2022

Powerful underwater sources, such as volcano eruptions and large explosions, can generate infrasonic waves, which remain detectable at distant receivers on shore. Evers et al. [Geophys. Res. Lett. 41, 1644–1650 (2014)] described observations of acoustic signals in air from the 2004 Macquarie Ridge submarine earthquake, by the infrasonic array IS05AU of the International Monitoring System. Infrasound propagated in the tropospheric and stratospheric waveguides and was received 1325 km from the epicenter. Specific physical mechanisms of the excitation of guided infrasonic waves by underwater sources are not fully understood. Here, we emphasize the potential role of local meteorological conditions. Scattering of ballistic waves from the earthquake epicenter by wind waves and sea swell on the ocean surface is a potent mechanism of excitation of normal modes in hydroacoustic waveguides (T-waves) [Godin, J. Acoust. Soc. Am. 150, 3999–4017 (2021)]. We investigate the hypothesis that the scattering of ballistic waves at the ocean surface also explains the earthquake excitation of acoustic normal modes in the tropospheric and stratospheric waveguides. Relative significance of the surface scattering and the previously proposed evanescent coupling mechanism is studied as a function of the wind speed, wave frequency, and the source depth.
Lighthill's theory applied to tornadoes as an infrasonic source
Authors: Liang Bin , Waxler Roger M. , Markowski Paul
Published: May 2022

It has been shown that tornadoes radiate infrasound, which can be detected at great distances. The physical mechanism underlying the radiation is not well understood. In this work, we use Lighthill's acoustic analogy to predict the pressure signals emitted from numerically simulated tornadoes. Several simulations will be considered including simulations produced using an LES model and provided by researchers from the Penn State Department of Meteorology and Atmospheric Science. The acoustical source produced from the LES tornado simulations shows interesting patterns in a narrow low-frequency band. By comparing different numerical models of tornadoes, we hope to determine what in a tornado is causing the infrasound radiation.
Vibroacoustic subtractive modelling: Principle of the reverse condensed transfer function approach and application to the prediction of the noise radiated by a partially coated cylindrical shell
Authors: Dumortier Florent , Maxit Laurent , Meyer Valentin
Published: May 2022

Substructuring methods are commonly used to solve vibroacoustic problems, as they allow studying complex systems by dividing them into smaller subsystems that can be studied separately. If they are generally used to couple subsystems, we are interested here in the decoupling procedure, consisting in subtracting a subsystem from a global system. Decoupling procedures can be used to perturbate an existing model in order to investigate the impact of a default on a given system, or to study problems with complex geometries, starting from a canonical system. In the framework of subtractive modelling, the reverse condensed transfer function (rCTF) method has been developed to decouple vibroacoustical subsystems that are initially coupled along lines or surfaces. The aim of this approach is to predict the response at any point of the final decoupled subsystem. The method will be presented on an academic test case consisting in the scattering problem of a plane wave by a rigid sphere immersed in an infinite water medium. Then, an example of industrial application will be proposed by studying the acoustic radiation of a partially coated cylindrical shell using the rCTF method.
Effects of F0 contour depth differences on school-age children’s speech recognition in a two-talker masker
Authors: Flaherty Mary M. , Libert Kelsey , Buss Emily
Published: May 2022

This study investigated the extent to which children (ages 5–17) can take advantage of differences in fundamental frequency (F0) contour between target and masker speech to improve speech-in-speech recognition. A number of studies show that differences in F0 and F0 contour between talkers support better speech-in-speech recognition for adults, suggesting it is an important cue for recognizing speech in multitalker environments. However, children’s use of F0 contour differences during speech-in-speech recognition is less well understood. In the present study, sentence recognition was measured adaptively in a two-talker speech masker. Target and masker sentences were recorded with either normal, flat, or exaggerated F0 contours. Results revealed that children’s sentence recognition was impacted by differences in F0 contour depth in both target and masker speech, but the pattern of results differed between children and adults in some conditions. For children, the consistent nature of the flat F0 contour often had a greater impact on speech recognition thresholds (SRTs) than target/masker differences in F0 contour depth. Observed age effects did not appear to be due to limitations in children’s ability to use F0 contour differences in general but are likely related to the perceptual salience of the target contour relative to the masker.
Classroom acoustics and the inclusion of hard of hearing children, helping the data be heard
Authors: Iglehart Frank , Johnson Cheryl DeConde , Wilson Stephen
Published: May 2022

Data on speech perception in children have led to acoustic accommodations in built schools for children with typical hearing but, despite compelling data, not for children who are hard of hearing. The ways to meet the acoustic needs of hard of hearing children are well researched and established in standards. After many years, however, the message is still not disseminating to architects, school districts, and building officials, and thus rarely makes its way into classroom construction. To help bring classroom accessibility to hard of hearing children, a team from the fields of acoustical engineering, architecture, and audiology is using speech perception data and computer simulations to promote inclusion in school design. This multi-year, multi-disciplinary effort began with earlier federal and foundation fundings for research on speech perception in hard of hearing children, which led to development of a new voluntary acoustic standard for schools by the American National Standards Institute. The goal of this work now is to get this standard into the hands of architects and school districts, and ultimately into building codes to have classroom acoustics designed for all students including those hard of hearing.
Use of static overpressure to assess the role of acoustic cavitation in ultrasound-mediated gene transfection
Authors: Ng Chun Kiat , Raymond Jason L. , Driscoll Claudia , Oldroyd Sophie , Huang Wei E. , Thompson Ian P. , Roy Ronald A.
Published: May 2022

Ultrasound-mediated DNA delivery (UDD) is a technique that utilizes ultrasound to aid the transfer of genetic materials into bacterial cells of interest (either in their planktonic or biofilm modes), resulting in new functionalities being displayed by the target microorganisms in-situ. The physical mechanism of UDD is poorly understood, which hampers its widespread adoption and scaling. To investigate the role of cavitation in UDD, we utilized a static pressure vessel designed to suppress cavitation while leaving other acoustic effects unaltered. Pseudomonas putida UWC1, a soil bacterium that is not naturally competent, was suspended in water and exposed to 40 kHz burst-mode ultrasound (400 cycle burst, 10 Hz repetition frequency, 60 s total) at an ambient pressure of either 1 bar or 9.5 bars. Noise diagnostics yielded inertial cavitation levels and transformed cells were quantified using a doubly selective reporter plasmid DNA. Samples exposed at 9.5 bars overpressure exhibited a drastic reduction in both cavitation activity and the number of transformed cells compared to those exposed at 1 bar. (Cell viability was not affected by pressure change.) The fact that transformation rates are reduced significantly when cavitation is suppressed suggests that acoustic cavitation is the major contributing factor in UDD.
Microbubble-endothelial cell interactions in 3D: Internalization of microbubbles and pore or tunnel formation for drug delivery
Authors: Beekers Ines , Langeveld Simone A. G. , Meijlink Bram , van der Steen Antonius F. , de Jong Nico , Verweij Martin D. , Kooiman Klazina
Published: May 2022

Ultrasound-activated microbubbles can locally enhance vascular drug delivery, but fully understanding the mechanism requires further investigation. The aims of this in vitro study were to (1) assess the initial single microbubble-endothelial cell (n = 301) 3D morphology, (2) determine whether the ligand type on the targeted microbubble affected this morphology, and (3) investigate the morphology’s influence on microbubble oscillation and drug delivery outcome, all using high-resolution 3D confocal microscopy in combination with ultra-high-speed imaging (∼17 Mfps). Non-targeted and IgG1-κ control microbubbles were not internalized by endothelial cells, while targeted microbubbles were internalized. The internalization depth was ligand-dependent, since microbubbles having αvβ3 as target were significantly more internalized than those with CD31. Although the internalized microbubbles (n = 246) had a damped oscillation upon ultrasound insonification (2 MHz, 200 kPa, 10 cycles), their ability to sonoporate cells (i.e., PI uptake) was increased. Upon sonoporation (n = 230), either pores or tunnels (i.e. transcellular perforation) were formed in the cell membrane for respectively intracellular or transcellular delivery. Fewer transcellular perforations and smaller pore areas were observed for internalized microbubbles. In conclusion, receptor-mediated microbubble internalization, its effect on microbubble oscillation, and resulting membrane perforation were revealed using a state-of-the-art imaging system, thereby providing novel insights.
Real-time acoustic modeling in the 2021 New England Shelf Break Acoustics experiment and beyond
Authors: DeCourcy Brendan J. , Lin Ying-Tsong , Zhang Weifeng G.
Published: May 2022

Real-time acoustic modeling in a shipboard context emphasizes the element of computation time in pursuit of in situ comparison between observed ocean data and model output. The importance of computation time highlights two competing factors in efforts to produce real-time acoustic predictions: the quantity of models to run and model accuracy. During the 2021 New England Shelf Break Acoustics (NESBA) experiment, a four-dimensional (4D) model of acoustic signals in the experiment network comprised of multiple stationary sound sources and receivers was produced using shipboard high-performance computing (HPC) resources. This effort involved hundreds of acoustic model runs across four separate source and receiver pairings and allowed for in-situ model adjustments, ultimately producing favorable comparisons between data and models in a matter of days. This presentation will examine the HPC approaches taken during the NESBA science cruise and address the planned improvements to the system for future scientific field experiments. [This work is supported by the Office of Naval Research.]
Efficient band-structure calculations of non-classically damped phononic materials by Bloch mode synthesis in state space
Authors: Aladwani Abdulaziz , Nouh Mostafa , Hussein Mahmoud I.
Published: May 2022

Bloch mode synthesis (BMS) techniques enable efficient band-structure calculations of periodic media by forming reduced-order models of the unit cell. Rooted in the framework of the Craig-Bampton component mode synthesis methodology, these techniques decompose the unit cell into interior and boundary degrees-of-freedom that are nominally described, respectively, by sets of normal modes and constraint modes. In this paper, we generalize the BMS approach by state-space transformation to extend its applicability to generally damped periodic materials that violate the Caughey-O’Kelly condition for classical damping. In non-classically damped periodic models, the fixed-interface eigenvalue problem may, in general, produce a mixture of underdamped and overdamped modes. We examine two mode-selection schemes for the reduced order model and demonstrate the underlying accuracy-efficiency trade-offs when qualitatively distinct mixtures of underdamped and overdamped modes are incorporated. The proposed approach provides a highly effective computational tool for analysis of large models of phononic crystals and acoustic/elastic metamaterials with complex damping properties. This investigation does not only extend the applicability of BMS techniques to the most generally damped models of periodic media, it also advances our understanding of the nature of damping modes and the non-trivial manner by which they contribute to the wave propagation properties.
New perspectives for active acoustic metamaterials
Authors: Popa Bogdan-Ioan
Published: May 2022

It is generally accepted that active acoustic metamaterials could, in principle, control impinging sound in ways not possible with passive media. One way to realize this potential is to employ structures composed of sensor-driver unit cells. In this approach, sensors are detecting the impinging wave and actuators are driven coherently with the sensed fields in order to generate almost arbitrary and programmable scattering profiles for the cells. This presentation will briefly review some of the rich and unusual dynamics of metamaterials based on these cells and, most importantly, will highlight the untapped potential of this architecture. In particular, the sensor-driver cells are not limited to generating a response in the same physical field as the excitation. Here, I will focus on metasurfaces that respond with light to acoustic waves. One possible application of these acousto-optical metamaterials will be discussed, namely, the realization of new acoustic imaging devices with potentially much larger resolutions than traditional imaging devices. [Work supported by the National Science Foundation under Grant No. CMMI-1942901.]
Drums speak too: An examination of modern percussion instruments in the jazz idiom
Authors: Scott E. K. Ellington
Published: May 2022

Jazz has been a leading force in the evolution of music in the United States. The complexity of rhythmic and harmonic languages has grown from the birth of jazz improvisation. Modern percussion instruments played a fundamental role in the development of rhythmic language. Improvised figures between the soloist and sectionals have cultivated a vocabulary still utilized by modern drummers and percussionists today. Moreover, evolving styles matured into a more sophisticated language, demanding a more refined instrument. This presentation explores the development of modern percussion instruments within jazz and improvised music, focusing on the historical and cultural aspects impacting the evolution of percussion instruments. Investigations of stylistic approaches and influences on musical styles will also be examined.
Numerical modeling and verification of room impulse response inference from the coherence properties of speech and music signals
Authors: Driscoll Erin , Bocko Mark , Smith Sarah R.
Published: May 2022

In previous work, we presented theory and motivating examples to demonstrate that the coherence properties of the harmonic partials of speech and music signals recorded in an acoustic space give information about the impulse response of the space. By analyzing auto- and cross-correlations between pairs of harmonics of the signal, we may “blindly” obtain the frequency-dependent reverberation time of the acoustic space. Assuming that the signal contains harmonically related partials with mutually correlated amplitude and phase modulations, a reasonable assumption for sources such as musical instruments or the human voice, this approach allows inference of information about the impulse response of an acoustic space. In this work, we verify this method for a variety of signals with different coherence times and amounts of pseudo-random amplitude and frequency modulations.
Sidelobe reduction using null subtraction imaging
Authors: Kou Zhengchang , Oelze Michael L.
Published: May 2022

In this work, we propose a novel anodization scheme where three different apodizations are introduced to create three separate images that are then combined nonlinearly to produce better image quality, i.e., null subtraction imaging (NSI). All apodizations were on receive only. The first apodization consisted of a zero mean weighting with the left half of aperture a weight of + 1 and the right half of aperture a weight of −1. The second apodization was a DC offset version of the first apodization and the third apodization was a flipped version of the second. Images were created by combining the envelope signals of three apodizations with different weights. The images were subtracted from one another resulting in a reduction in sidelobe levels, a narrowing of the main lobe and improvement in image quality. An L14-5 array transducer and a Verasonics system were used to capture the RF channel data using seven plane waves spanning angles between −12° and 12°. Both coherent compounding and filtered incoherent compounding were used as a tradeoff between lateral resolution and contrast to noise ratio (CNR). Images were constructed from wire targets, a tissue-mimicking phantom, and rat tumors in vivo. Image quality was assessed through the CNR and intensity of sidelobes visible in the images. Images created using NSI were compared to images created using Hanning apodization with delay and sum (DAS) and a generalized coherence factor (GCF) approach. Improvements in image quality were found when using NSI compared to the other methods.
Acoustic scattering by smooth and rough elastic cylinders insonified by directional sonars
Authors: Al Mursaline Miad , Stanton Timothy K. , Lavery Andone C.
Published: May 2022

Realistic sonars radiate spherically spreading waves and have directivity. Therefore, they insonify a target over a finite number of Fresnel zones and span a continuum of oblique incident angles, even when the center of the beam is at normal incidence. These effects strongly influence both the overall scattered pressure levels and resonances. For example, because of the spreading of the beam and associated oblique insonification within the beam, axially propagating guided waves are generated that would not have otherwise existed for an idealized incident plane wave. This investigation illustrates practical sonar properties and their effects on cylinder scattering both theoretically and experimentally. An approximate theoretical formulation for acoustic scattering by elastic cylinders is proposed in the form of a simple line integral accounting for these properties. Laboratory measurements are also presented to test the range of validity of the formulation for smooth cylinders under both monostatic and bistatic configurations. This study is further extended for the case of rough elastic cylinders.
Exploring conditions required for the subwavelength focusing of sound in the near field of an array of resonators using time reversal
Authors: Basham Andrew , Kingsley Adam D. , Anderson Brian E.
Published: May 2022

This presentation will discuss the time reversal focusing of audible sound over an array of Helmholtz resonators. The presence of the resonators modifies the phase speed of waves, thereby lowering the effective wavelength, in the near field of the focus. It is shown experimentally what conditions are necessary to obtain super resolution. Frequencies above the resonators’ resonance frequency do not result in super resolution. In order to achieve super resolution in the plane of the resonators, the focused waves must be confined to propagate only in the plane of the resonators. When waves converged in three dimensions, super-resolution was not observed but when a 2-D waveguide was used, and super-resolution was observed.
Effect of high-density additional rippled patterns on ripple density resolution thresholds
Authors: Tomozova Marina , Supin Alexander , Nechaev Dmitry I. , Milekhina Olga N.
Published: May 2022

This study aims to spot an effect of the density of an additional rippled signal on ripple density resolution thresholds when this density is greatly exceeding the density of the main signal. In such a case a spectrum is formed from two harmonic functions. Therefore, a phase-reversed spectral ripple resolution test was used in this research, which includes two experimental paradigms. In both 2 oct narrowband white noise passes through pre-made filters. A ripple density of the additional signal was varied from 10 to 50 ripples/oct. In a rippled test and reference stimuli the mean resolution was 9 ripples/oct. This fact supports the involvement of cochlear excitation patterns for the discrimination of such signals. In a test with the stimuli with an additional rippled signal and non-rippled reference signal the thresholds cannot be reduced to mean value. However, the ripple density resolution thresholds for 20, 30, and 50 ripple densities of additional signal gravitate towards the value of 11,25 ripples/oct. The ripple density resolution thresholds for 10 and 15 ripples/oct are higher than the other values what suggests a special combination of spectral and temporal mechanisms.
Talker adaptation or “talker” adaptation? Musical instrument variability impedes pitch perception
Authors: Shorey Anya E. , King Caleb J. , Theodore Rachel M. , Stilp Christian E.
Published: May 2022

When perceiving speech spoken by a single talker versus multiple talkers, listeners show perceptual benefits such as increased accuracy and/or decreased response time. There are several theoretical explanations for this talker adaptation phenomenon; one way to distinguish among these is to test whether adapting to stimulus structure is speech-specific or general to auditory perception. Music, like speech, is a sound class replete with acoustic variation. Here, participants completed a musical task that mirrored talker adaptation paradigms. On each trial, participants heard a tone and reported whether it was the lower (D4, 294 Hz) or higher pitched tone (F#4, 370 Hz). Tones were presented in a single- or mixed-instrument block. We predicted that perceptual benefits from structure in the acoustic signal are not specific to speech but are a general auditory response. Accordingly, we hypothesized participants would respond faster in the single-instrument block, consistent with speech studies that used a similar paradigm. Pitch judgments were faster (and more accurate) in the single instrument block, parallel to results from talker adaptation studies. In agreement with general theoretical approaches to auditory perception, perceptual benefits from signal structure are not limited to speech.
Non-coherent turbo coded frequency shift keying for reliable covert underwater acoustic communications
Authors: Jeong Hyun-Woo , Jung Ji-Won , Kim In-Soo
Published: May 2022

This paper presented efficient receiver structure of non-coherent turbo coded FSK signals for maintaining covertness and performance in underwater communication. In aspect to covertness, direct sequence spread spectrum method, which used to hide the transmitted signal by transmitting it at low power and, thus, making it difficult for an unintended listener to detect the signal in the presence of background noise. In aspect to performance improvement in the underwater acoustic environment with multipath and Doppler spreading, non-coherent FSK which is not required phase information, weighted multiband technology, and turbo equalization model with rate of 1/3 were suggested. In order to analyze the performance by applying four bands and spreading chips with 8 and 32, the experiment was conducted on a lake by moving in the range of 300m to 500m. Through the experimental results, we confirmed the performance was improved as increasing number of bands, turbo iterations, and spreading chips. Furthermore, weighted multiband technology which allocates lower weight to inferior bands based on preamble error rates were applied for some failed packets, all packets were decoded successfully. [This research was funded by Agency for Defense Development, South Korea, Grant No. UD200010DD.]
Technical and electroacoustic aspects of miniature omnidirectional sound sources used in acoustic scale modeling
Authors: Chojnacki Bartlomiej , Kamisinski Tadeusz
Published: May 2022

Acoustic similarity theory allows us to create scaled room acoustic models which are simple to construct but usually difficult to measure correctly. One of the most common problems is the sound source, which works in the wide frequency range (800–40000 Hz, 500–63000 Hz) and has an omnidirectional sound propagation pattern. The lecture will present the novel approach for miniature sound sources design and creation for the most common measurement functions—laboratory objects and materials measurements (absorption, diffusion) in the scaled reverberation chamber, sound insulation scale modeling, and the room acoustic measurements in reduced models. Each of those applications has special sound source requirements, which allow us to differentiate their construction type. The most important aspects of the designing process were investigated, such as the number of transducers used and their placement, types of speakers, enclosure shape, and dimensions. The lecture will expose the sound sources used in Technical Acoustic Laboratory in AGH, Cracow, for the given measurement functions. The design recommendations developed based on FEM modeling, and experimental testing will be discussed regarding the existing objects, allowing future users to recreate in similar shape or adjust to other, predefined scale modeling measurement functions.
Use of virtual reality in designing and developing soundscape for dementia care facilities
Authors: Talebzadeh Arezoo , De Vriendt Patricia , Devos Paul , Botteldooren Dick
Published: May 2022

Sound plays an essential role in making people conscious of space and time; however, once the cognitive ability declines, the same stimulus can become a source of anxiety and disturbance. People with dementia have difficulties identifying and interpreting their sensory stimuli; perception of space can become confusing and disturbing. They perceive and understand the sonic environment differently; the most obvious difference is the wrong meaning they may give to the sounds they notice due to changing mental association. A well-designed soundscape can help to reduce anxiety and distress and improve sleep and overall quality of life. In this research, a personalized soundscape was implemented in the dementia unit, adding recognizable sounds to the sonic environment to give people a feeling of safety, elevating their mood and activating them. Virtual Reality is a tool to present the result to stakeholders and further implement soundscape into designing care facilities. Soundscape is the sonic environment as perceived in context; VR helps define the context. Walking through the space while hearing the soundscape demonstrates how sound helps spatial orientation and understanding of time. We need to remember that people with dementia have a different mental model, and VR can help feature diverse mental models. The goal is to use Virtual Reality to enhance the soundscape experience during the design and development, especially for care facilities.
Optimization of loudspeaker positions for virtual auditory displays in a free-field environment
Authors: Wells Nathaniel , Sommerfeldt Scott D. , Blotter Jonathan D.
Published: May 2022

Virtual acoustic environments are created by mimicking the pressures of real acoustic sources at a listener’s ears. In this way, a listener can perceive virtual acoustic sources as coming from any desired direction. There are multiple methods to accomplish this using headphones or loudspeaker arrays, but not all are practical for everyday use. Some use cases limit the use of headphones or the number and position of loudspeakers, such as automobiles and home theater systems. These limitations also put bounds on the performance of each possible system, such as allowable head movement and the accuracy of localization. An exhaustive-search optimizer was used to find the performance of various sparse loudspeaker arrays, given a limited number of possible loudspeaker positions in a free-field environment for a single stationary listener. The optimizer sought to maximize allowable head rotation and translation and to minimize localization errors. Arrays consisting of two or four loudspeakers were considered using a spherical head model to find the necessary head-related transfer functions and cross-talk cancellation was used to create the virtual acoustic environment. From the results, pareto fronts were created that can be used to find the best loudspeaker array configuration for given design constraints.
Measuring ongoing delay with reverse noise
Authors: Joris Philip X.
Published: May 2022

Counts of spike coincidences provide a powerful means to compare responses to different stimuli or of different neurons, particularly regarding temporal factors. A drawback is that these methods do not provide an absolute measure of latency, i.e., the temporal interval between stimulus and response. It is desirable to obtain such a measurement within the same analysis framework of coincidence counting. Single neuron responses were obtained from several fiber tracts (nerve, trapezoid body, lateral lemniscus) in two species to a broadband noise and its polarity-inverted version. The spike trains in response to these stimuli are the “forward noise” responses. The same stimuli were also played time-reversed. The resulting spike trains are then again time-reversed: these are the “reverse noise” responses. The forward and reverse responses were then analyzed with the coincidence count methods we have introduced earlier. Latency measurements derived from correlograms between forward and reverse noise responses show maxima at twice the latency value measured with other methods, as expected. Correlograms were often asymmetric but, at low-characteristic frequencies, were well-predicted by crosscorrelation of the reverse-correlation function and its reverse. We conclude that reverse noise provides an easy and reliable means to estimate latency of auditory nerve and brainstem neurons.
The impact of prior topic awareness on listening effort during speech perception
Authors: Gianakas Steven P. , Winn Matthew B.
Published: May 2022

Most standard speech perception tests use unrelated sentences where the topic changes for each stimulus. This unrealistic paradigm is expedient but might overlook an important aspect of speech processing and effort, which is how listeners use expectations and topic awareness to enable easier repair of misperceived words. We hypothesize that the effort of mentally repairing misperceived words will be reduced when individuals have advance topic awareness of upcoming sentences. In this study, individuals with normal hearing and hearing loss heard sentences with a masked target word that required retroactive mental repair using later context. Sentences were either preceded by the presence or absence of a related priming word presented visually to simulate advance topic knowledge. Listening effort for these sentences was measured by changes in pupil size that were linked with the exact timing of the word being repaired. When the target word is masked in a sentence, pupil dilation increases immediately after the missing word, and that dilation is modulated by the helpfulness of the prime before the sentence.