bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrasound pulse-echo measurements in a large-volume press at the High-Pressure Collaborative Access Team (HPCAT)
Authors: Hrubiak Rostislav , Sturtevant Blake T. , Kenney-Benson Curtis , Bommannavar Arun , Rod Eric , Somayazulu Maddury , Velisavljevic Nenad
Published: November 2023

The large-volume press at beamline 16-BM-B, at the High-Pressure Collaborative Access Team (HPCAT) facility at the Advanced Photon Source (APS), Argonne National Laboratory, offers a comprehensive platform for in-situ characterization of materials' atomic structure and bulk properties under high pressure and/or high-temperature (HP-T) conditions. The beamline is equipped with a Paris-Edinburgh type press with in-situ X-ray, electrical, optical, and ultrasound probes. The ultrasound pulse-echo technique, in conjunction with other techniques, such as energy-dispersive X-ray diffraction, X-ray radiography, and thermal/electric measurements, provides relevant data on material properties, including elastic constants, equation of state, and phase transitions, at HP-T conditions. The beamline is currently undergoing a major redesign to coincide with the APS upgrade. Among other developments, the ultrasound measurements at the upgraded beamline will be optimized with the addition of rotational X-ray tomography, as well as new capabilities for online data analysis. These advancements, together with the improved beamline optics, will improve accuracy and significantly reduce the time needed for data collection, allowing for faster experiments and higher throughput. The presentation will provide an overview of beamline 16-BM-B with a specific focus on acoustic measurements using the ultrasound pulse-echo technique and relevant applications. The beamline's expanded capabilities and scientific examples will be presented.
Spatio-temporal measurement of density distribution in oscillatory boundary layer using phase-shifting interferometer
Authors: Shoji Eita , Maddi Anis , Biwa Tetsushi
Published: November 2023

The objective of this study is to directly measure the acoustic density fluctuations of a gas confined between two parallel plates. For this purpose, we originally developed a phase-shifting interferometer, where a polarizing Mach–Zehnder interferometer was incorporated with a polarization camera. This enabled us to achieve a time resolution of 70 FPS in addition to the high-resolution measurement by the phase-shifting technique. The test beam passes through the two parallel plates of width 10 mm, where an acoustic field is generated using a loudspeaker that produces high acoustic pressures (up to 3000 Pa) at frequencies ranging from 0.5 to 5 Hz. In this work, we successfully measure the density fluctuations, which are otherwise difficult to obtain using conventional optical interferometers. Additionally, the experimental results are compared to the visco-thermal acoustic theory, where a good agreement was reached, affirming the effectiveness of this phase-shifting interferometer. Furthermore, using the proposed setup, we are able to measure and deduce the spatiotemporal variations of the pressure, density, and temperature without interfering with the acoustic field, which distinguishes it from measurement probes like thermocouples. This interferometer can be used to study more complex phenomena such as edge effects in thermoacoustic engines.
Acoustic attenuation coefficient measurement in extreme environments: Experimental characterization of uncertainty in multiple-reflection method
Authors: Liang Suzi , E. Treeby Bradley , Martin Eleanor
Published: November 2023

Measuring acoustic properties in extreme environments, involving hazardous chemical samples or temperature above 50ºC or below 0ºC, is challenging yet crucial for understanding waveform interactions with materials, with applications in fields like non-destructive testing (NDT) and medical applications. Multiple-reflection methods (MRM), using a buffer-rod between transducer and sample, offer a solution. Yet, the impact of variables like contact force, buffer-rod size, and surface roughness on the accuracy and precision of MRM measurements remains unvalidated. To address this, we introduce a system and experiments to quantify the accuracy of measurements of acoustic attenuation coefficient. Results demonstrate the substantial impact of contact force on system accuracy and precision, reflected by a decrease in the measured attenuation coefficient at 0.5 MHz from 3.8 to 1.5dB/cm with increasing contact force. Effects of buffer-rod width were less pronounced and supported the theory that a cylindrical buffer-rod with twice the radius of the transducer is sufficient. Interestingly, surface roughness, despite being over 150 times smaller than the wavelength of the acoustic signal, influences measurement accuracy. This study illuminates the crucial role of system factors on measurement accuracy and uncertainty, which will aid optimization of measurements for diverse practical applications.
Engineering Helmholtz resonators for directional low-frequency sound attenuation
Authors: Domingo-Roca Roger , Feeney Andrew , Windmill James , Jackson Joseph
Published: November 2023

Controlling the absorption and diffusion of sound in the audible range constitutes an exciting field of research. Acoustic absorbers and diffusers perform extraordinarily well at high frequencies with sizes comparable to the wavelength of the working frequency. On the other hand, efficient low-frequency attenuators demand large volumes leading to unpractical sizes and high manufacturing costs. However, can the size of the resonator be reduced while also decreasing the working frequency? The answer is, counterintuitively, yes. This work investigates this phenomenon by studying a series of 3-D-printed monoatomic metamaterials based on membrane-coupled Helmholtz resonators. The results reveal that these systems, apart from significantly decreasing the bandgap frequency by around 36%, produce a cardioid directional response that contrasts with the omnidirectional response from traditional Helmholtz resonators. The obtained results suggest that by following this approach, low-frequency attenuation can be achieved via miniaturised devices while additionally providing them with a sense of directionality. This combination of features makes these sensors the perfect candidates for the next generation of acoustic hearing devices and acoustic attenuators, since the freedom that 3-D-printing provides allows for fine control of wave manipulation.
Probing the phonological-coding deficit in dyslexia with vowel length perception
Authors: Morris David J. , Juul Holger
Published: November 2023

There is an established linkage between dyslexia and anomalous processing of speech sounds. We probed this in a Danish language context with vowel length tasks based on “kugle” ball /ku:lə/ and sequential deletions of the vowel portion to yield “kulde” coldness /kulə/. Vowel length continua are methodologically advantageous as they do not involve the perception of a sudden phonetic change that may instead tap other auditory processing abilities. Identification and discrimination tasks were administered to tertiary (n = 28), reading impaired (n = 26), and lower secondary students (n = 20), and the latter were approximately aged matched to the reading-impaired group. Identification functions derived from regression modelling of the responses showed that the dyslexics had significantly flatter curves than the other groups. Moreover, the secondary and dyslexic groups differed at the long vowel extremity of the continuum. Discrimination results showed that mean peak sensitivity of the tertiary students was higher than that of the secondary and dyslexic students. These results indicate that the phonological-coding deficit observed in dyslexics may be indexed by vowel length identification. Furthermore, identification results suggest that the nature of the phonological-coding deficit concomitant with dyslexia may stem from a lack of precision in processing the minimally modified longer vowel stimuli.
Correlates of word likeness in the perception of pseudowords
Authors: Tucker Benjamin V. , Kelley Matthew C.
Published: November 2023

New words are often introduced into languages from borrowings or neologisms. Pseudowords (possible words of a language that have not yet been assigned meaning) are used in many experiments to test aspects of speech perception. However, what we know about the perception of pseudowords is relatively limited. In this study, we investigate word likeness ratings of pseudowords on a 1–7 scale. A total of 659 listeners responded to sets of 200 pseudowords from an item list of 9599 English-sounding pseudowords varying in number of syllables and morphological complexity. We analyze the listeners' responses with the following predictors: phonotactic predictability, duration, phonological neighborhood density, phonological uniqueness point, pseudo morphological complexity, and acoustic distinctiveness. We analyze the ordinal data to identify how these predictors influence listeners’ ratings. We also take average word likeness ratings of the pseudowords and use them to predict a different set of listeners’ reaction times in a lexical decision task. In this presentation, we discuss what properties of the pseudowords influence what makes them seem more word-like or not and how word-likeness affects auditory word recognition.
The effect of perceived human-likeness on voice-user interface–directed speech
Authors: Maitinsky Marcell , Walter Maddy , Cardoso Amanda , Islam Md Jahurul , Gick Bryan
Published: November 2023

Many interact daily with voice–user interfaces (VUIs), but acoustic research on VUI-directed speech (VDS) is relatively new. Prior work indicates intensity and F0 correlate with VDS [Cohn et al., 2022, JPhon 90]. Multiple acoustic variables of VDS were analyzed to explore if VDS is a register distinct from human-directed speech (HDS) and whether perceived human-likeness of VUI voices affects VDS characteristics. 27 participants’ Zoom recordings of 13 pre-scripted prompts and pre-recorded responses from two Amazon AWS-Polly-generated VUI voices (rated for human-likeness independently and by participants) were acoustically analyzed for word-initial voiceless plosives voice onset time (VOT), pitch variation, and vowel quality and quantity. Results of linear mixed-effects models indicate evidence of VDS-specific acoustic characteristics, some of which are affected by participants’ perceived human-likeness of the voices. Differences in pre-exposure and VUI interactions occur for /p/ VOT in consonant clusters, vowel duration (except /ɪ/), and /ɑ/ F2. Statistical differences are found for /p/ VOT in consonant clusters and vowel quality (e.g., /ɑ/ F1 and F2, and /ɪ/ F2) based on perceived human-likeness by participants. This study contributes to the growing VDS work examining how humans speak with devices and what affects VDS, which may influence considerations of VUI voice development.
Children's listening effort for L2-accented speech
Authors: Altmiller Ruth , Van Engen Kristin J.
Published: November 2023

Speech perception is a complex task that can become challenging in certain conditions, such as listening to speech in unfamiliar accents. Using task-evoked pupillary response (TEPR) and dual-task procedures, prior research has shown that adults recruit additional cognitive resources when processing fully intelligible L2-accented speech compared to speech in their own L1 accent (McLaughlin and Van Engen, 2020; Brown et al., 2020). In the current study, we used pupillometry to investigate this effect in children (n = 35, ages 5;0 – 8;11) and ask whether prosodic variation can explain any differences in listening effort. Using Growth Curve Analysis, we found that unlike adults, children do not appear to recruit extra cognitive resources to process intelligible L2-accented speech. Like adults, however, pupillary response declined more rapidly for L2-accented speech across the experiment than for L1-accented speech, indicating either rapid adaptation or fatigue. Additionally, we identified three prosodic measures (relative word duration, pitch stability, and pitch range) that were related to speech adaptation/fatigue for both accent conditions, but in opposite directions. Although children do not appear to upregulate listening effort for L2-accented speech like adults, they appear to use prosodic cues differently for L1- versus L2- accented speech as they adapt to speech.
Spatial sampling versus acquisition time of room impulse responses for low-frequency sound zones
Authors: Cadavid José , Møller Martin B. , Bech Søren , van Waterschoot Toon , Østergaard Jan
Published: November 2023

Sound zone methods aim to create multiple listening areas within a room, allowing independent playback of different audio content. Achieving this requires a loudspeaker array, multiple microphones per sound zone, and a set of control filters, which design involves the room impulse responses (RIRs) between loudspeakers and microphones. Under certain acoustic conditions, acquiring these RIRs is possible using very short acquisition times. At lower frequencies, longer wavelengths enable spatial sampling of the sound zones with fewer points, reducing the number of microphone positions required and amount of data to process. This study exploits this characteristic to render and evaluate low-frequency sound zones in two real rooms, with few spatial sampling points. We assess the performance by objectively evaluating multiple spatial sampling configurations and RIR acquisition times. Furthermore, we evaluate the system's ability to control sound beyond the sampled regions by assessing the sound field over wider areas. For sound zones roughly the size of a human head, satisfactory performance is achieved in low reverberation conditions with at least two microphones per ear, even for RIR acquisition times as short as 150 μs. Conversely, the performance degradation in highly reflective environments cannot be compensated using additional microphones nor longer acquisition times.
Features and limitations of the Weston α parameter as a descriptor of seafloor bottom loss
Authors: Jones Adrian D.
Published: November 2023

It is straightforward to prove that, for very small seafloor grazing angles, the Weston α parameter [Weston, J. Sound Vib. 18, 271–287, 1971] provides a reasonable estimate of the slope of bottom loss in dB versus grazing angle. However, for some circumstances, the descriptions of bottom loss versus grazing angle based on the Weston α parameter are valid over a considerable span of grazing angles and to large loss values. By studying the seafloor reflection in terms of impedance, and as linked to the geoacoustic parameters, greater knowledge of the features and limitations of the Weston α parameter as a descriptor of seafloor bottom loss has been obtained. This paper covers the theory, applicable to a variety of seafloor types, each of a uniform half-space. Seafloors considered include those with either fast or slow compressional speed. For fast seafloors, shear speed is considered as one of less than, near to, or greater than the water sound speed. The effects of each of compressional and shear absorption in the seafloor are considered. Numerous sample plots of bottom loss versus grazing angle are used to demonstrate the accuracy of the analysis.
Model updating of flowering snapdragon (Antirrhinum litigiosum) biomechanical responses to vibro-acoustic stimuli
Authors: Nerse Can , Mohapatra Abhishek R. , Oberst Sebastian , Navarro-Payá David , Etxeberria Jone , Matus José T. , Bianco Lorenzo , Tucci Maria R. , Cumino Elena , Casacci Luca P. , Barbero Francesca
Published: November 2023

The combined variation in gene expression and environmental conditions during flower development can result in phenotypic differences in shape, size, and material composition. Biomechanical responses in flower organs due to external stimuli can be mechanically measured at various levels. Here, we investigate snapdragon (Antirrhinum litigiosum) response to vibro-acoustic stimuli by an interdisciplinary model updating framework. In a climate-controlled setup, sweep signals and artificial signals representative of plant pollinator species were given as excitation input through a loudspeaker to a set of plants; vibrations of the flower organs were measured by laser Doppler vibrometry. Geometric features of the plants were identified using LiDAR combined with photogrammetry, while the density distribution in the flower organs and internal dimensions were estimated using micro-computed tomography scans. A computer model using finite element method was used to identify material properties of the flower organs by combining time domain measurements and dimensional classification. Results demonstrate density and stiffness gradient in the corolla contributing to a modal activity that is adaptive to local conditions and pollinators, but resilient against external noise. The framework outlined herein may give clues to which pollinators induce early-plant responses. [The authors acknowledge the support of the Human Frontier Science Program (HFSP) grant RGP0003/2022.]
On the potential of using Distributed Acoustic Sensing (DAS) to build teleseism based ocean-tomography network
Authors: Dall'Osto David R.
Published: November 2023

The sound from marine teleseisms rank among some of the loudest in Earth’s Oceans, typically radiated into the ocean near the epicenter and propagating across the entire ocean basin. Acoustic sensing on ocean observatories provide a critical path to better understand origins of these low-frequency sound waves known as T-phases, and structure of the ocean over the megameter propagation through the ocean. Of the emerging technologies implemented on these observatories, distributed acoustic sensing (DAS) has the potential to revolutionize marine seismoacoustics. DAS can be implemented on unused oceanic fibers on the continental slopes surrounding an ocean basin could readily enable a teleseism based ocean-tomography network with surprisingly little new infrastructure. In November 2021, a DAS system installed on two runs of fiber optic cable that connect to an ocean observatory measuring offshore volcanic activity, detected a few examples of teleseismic T-phases. Combined with other hydroacoustic ocean observatories in the Pacific Ocean, the T-phase origins are localized to bathymetric features over 100 km from the epicenter, an important consideration when utilizing these T-phases as sources of opportunity to study the ocean.
Performance of distributed acoustic sensing relative to co-located hydrophone measurements
Authors: Douglass Alexander S. , Abadi Shima
Published: November 2023

Distributed acoustic sensing (DAS) is a technology that transforms telecommunication fiber optic cables into dense sensor arrays by continuously transmitting pulses of light down the cable and measuring backscattering from natural inhomogeneities within the fiber cable. The technology can densely sample the acoustic field over long ranges (up to 100 km), providing a means for large scale passive acoustic monitoring. The DAS Calibration Experiment 2022 (DASCAL22) provides 9 days of co-located hydrophone and DAS data in Puget Sound, WA. The DAS data were recorded with a 2kHz sampling rate over ∼3.5 km of cable in a channel reaching close to 100 m depth and with DAS channels spaced 6.38 m. A combination of an active source broadcast from 1, 5, and 10 m depths, and passive signals (primarily boat noise) are used to investigate the capabilities of DAS to sense a range of frequencies and the impacts of the environment on those capabilities.
Attenuation study with hemoglobin microbubbles for acoustic blood oxygen level dependent imaging
Authors: Akter Nasrin , Chaudhary Sugandha , Sirsi Shashank
Published: November 2023

A new microbubble-based biosensor for BOLD imaging applications was developed and acoustically characterized using ultrasound. The biosensor design was based on the use of hemoglobin protein as a shell component of microbubbles, which undergoes changes in structure upon oxygen binding, leading to changes in the mechanical properties of the shells. The acoustic characterization was performed using an ultrasound acoustic transducer with a center frequency of 1 MHz, which was used both as a source and a receiver. The transducer transmitted 5 us pulses at a PRF of 10 Hz at peak-negative pressures ranging from 0 to 0.1 MPa. The microbubbles were then excited, and their signals were measured and transformed to frequency domain using Fast-Fourier transform, from which attenuation was computed. The oxygen-saturated hemoglobin microbubbles were added to either oxy or deoxy PBS at a concentration of 4.5 × 6 mB/ml to collect the microbubble signal. The results showed that the biosensor has potential for use in BOLD imaging applications. The results showed that hemoglobin microbubbles were displaying distinct attenuation properties between oxy and deoxy conditions, thereby showing response to different levels of oxygen.
Identification of the parametric array loudspeaker system using differential Volterra filter
Authors: Ma Yunyao , Yang Jun , Zhu Yunxi , Kuang Zheng
Published: November 2023

The self-demodulation property of a parametric array loudspeaker (PAL) system can peel off audible sound modulated on ultrasonic wave and deliver it with high directivity, but also introduces nonlinear distortion. The PAL system can be modeled by the Volterra series expansion in any acoustic field region. However, measurements of Volterra kernel using simple frequency sweep excitation signals may not provide adequate information about the nonlinear system, and the use of wideband signals such as speech signals makes convergence difficult. Based on the Westervelt model, we propose a PAL system identification method utilizing the differential Volterra kernel. The results demonstrate superior fitting performance for real swept frequency output data and speech signal output data compared to the existing one-dimensional Volterra filter (ODVF). Additionally, the proposed method exhibits fewer parameters and faster convergence speed than the traditional volterra kernel.
A study on improving the sound radiation capability of stepped-plate parametric array loudspeakers
Authors: Oh Beomseok , Kim Chayeong , Lee Dongwoo , Rho Junsuk , Moon Wonkyu
Published: November 2023

It is well known that Parametric Array Loudspeakers (PALs) produce highly directional audible sounds. However, their widespread adoption is hindered by their high cost, which is primarily attributable to the use of an array of ultrasonic radiator units. To address this issue, our research group introduced stepped-plate parametric array loudspeakers (SPPALs) in 2018. SPPALs utilize a single-structure directional ultrasonic radiator, featuring steps of half-wavelength thickness on the radiating plate. This design mitigates the problem of poor directivity, especially at high frequencies, caused by destructive interference resulting from the plate's flexural mode. Moreover, SPPALs can offer cost advantages compared to commercial PALs due to their single structure. However, understanding the vibration characteristics of SPPALs in relation to sound radiation performance is quite challenging due to their various design parameters. In this study, we present an analytical approach that offers a quantitative method for enhanced sound radiation capability. We present a simplified vibration model (SVM), which enables an efficient design process based on a comprehensive analysis of vibration characteristics. By minimizing reliance on finite element method (FEM) simulations, our method expedites the design of various directional speaker systems.
Subjective speech enhancement performance of a hearable with transparency and spatial frequency-weighted dereverberation
Authors: Ghanavi Reza , Jin Craig
Published: November 2023

Preserving natural binaural cues combined with directionality and robust dereverberation is crucial for successful sound enhancement via hearables. In this study, we subjectively evaluate the performance of a real-time hearable prototype that aims to enhance frontal speech and spatial cues in complex environments using a new dereverberation algorithm and acoustic transparency. Our real-time algorithm exploits the spatial frequency-weighted coherence-to-diffuse ratio estimated between the conchal microphones and produces directional binaural gains using a Wiener filter for sound enhancement. The new hearable system can be customized or adapted to a given environment for optimum performance in different frequency bands and preserves natural binaural cues for all individuals by symmetrical spatial filtering. We use the real-time prototype to evaluate the perceived speech intelligibility in noise by a Matrix framework for normal-hearing subjects in a reverberant classroom. We also use a multi-stimulus with hidden reference and anchor-like framework to evaluate the perceived speech quality and listening comfort of several stimuli simulated for HATS in the same environment. Results show that speech intelligibility and listening comfort in noise can be significantly improved for the real-time hearable using the new algorithm with optimized parameters compared with several state-of-the-art coherence-based algorithms implemented in a similar device.
Why bundengan musicians always drench their instruments prior to playing
Authors: Parikesit Gea O. , Kusumaningtyas Indraswari
Published: November 2023

Bundengan is an indigenous musical instrument from Indonesia. It evolved from a bamboo-woven dome originally used by duck herders as a portable shelter during rain and sun. By embedding strings and bars into the dome, the herders turned this shelter into a unique instrument, under which they sit and play music. Bundengan musicians have learned from experience that the instrument sounds better when played under the rain. Nowadays, they use various ways to drench their instruments prior to playing, such as soaking it in fish ponds or putting it under the shower. We explore the physics of why wetter bundengan sounds better. First, we analyze the construction steps of the bamboo dome: the weaving of the bamboo splits, the bending of the woven splits, the layering of bamboo culm sheaths on the woven splits, and the deformation of the sheaths during wetting. Second, we analyze the coupling between the mechanical vibrations in the dome and the acoustical waves from the instrument. Certain conditions of the coupling may lead to an evanescent acoustical field dominating over the radiating acoustical field, which may explain why the best bundengan sound is confined only to under the dome, where the musicians sit.
Sound absorption characteristics of a compact meta-structure under grazing flow
Authors: Li Ying , Choy Yatsze
Published: November 2023

This study proposes a compact meta-structure for broadband and low-frequency sound absorption under grazing flow. It comprises a microperforated panel (MPP) and resonators with embedded tunable orifices and C-shaped cavities. The sound absorption characteristics of the proposed absorber are investigated via theoretical model (acoustic impedance circuit) and numerical model (finite element method). Consistent predicted results from both models manifest that the proposed meta-structure possesses good absorption capacity under a deep-subwavelength scale, compared to the conventional MPP absorber. To simultaneously achieve better low-frequency and broadband noise damping, a parallel configuration of the meta-structure and an MPP absorber is studied numerically and experimentally. Besides, notable variation on the acoustic performance of the proposed absorber is observed in case of grazing flow, which leads to the decline of the absorption peak and makes the peak wider than that without flow. The practical significance of this study is that it proposes a promising meta-structure for wide frequency sound attenuation applications; furthermore, it elucidates the flow effects on the acoustic performance of the meta-structure, providing a route to reduce flow-related noise in a broad frequency range.
The relevance of bubble dynamics in ultrasonic/sonochemical processes
Authors: Ashokkumar Muthupandian
Published: November 2023

Acoustic cavitation bubble dynamics has been extensively studied by physicists and mathematicians. Process intensification is primarily studied by chemical engineers. Chemists tend to focus on bubble dynamics in a multibubble field to optimize the physical and chemical forces generated during acoustic cavitation with an intention to maximise/intensify chemical processes. To achieve process intensification successfully a multidisciplinary approach is required. Our early work on multibubble cavitation unveiled various factors that contribute to process optimization. For example, while single bubble dynamics can estimate the maximum bubble temperatures, they may not be relevant to achieving higher chemical yield, which in turn depends on varus other factors such as average bubble temperatures, number of active cavitation bubbles, etc. Other factors critical for process intensification include the generation of a homogeneous cavitation field, control over mass transfer effects caused by bubble oscillations, reactor design, etc. The presentation will provide an overview on the relevance of single and multibubble bubble dynamics in ultrasonic/sonochemical processes.
Higher-order statistical moments of predicted sonic boom waveforms through turbulence
Authors: Lonzaga Joel B.
Published: November 2023

Sonic booms generated by supersonic aircraft are affected by turbulence in the atmospheric boundary layer through which they propagate. Turbulence effects lead to random variability of the sonic boom waveforms measured on the ground, complicating the prediction of such waveforms. As an initial effort to predict the waveform variability, the solution of the coherent or mean sonic boom waveform has previously been formulated by the author. The current paper extends the formulation to derive an expression of the second-order statistical moment necessary to calculate the variance of the spectral amplitudes. Since the derivation uses a full wave equation, results using the derived expression will be compared with those obtained using a parabolic approximation. In order to fully quantify the uncertainty of our predictions, the higher order statistical moments are also formulated and are shown to be approximately zero. Consequently, the probability density function (pdf) of the spectral amplitudes is predicted to be Gaussian. The formulation is further extended to determine the pdf of the loudness of sonic booms and quantify the uncertainties associated with the loudness prediction. Results from the formulation are compared with available flight test data.
Acoustically-mediated orientation and navigation in rooms
Authors: Steffens Henning , Ewert Stephan D.
Published: November 2023

While the visual system provides the dominating sensory input in sighted humans for awareness, orientation, and navigation, in low-light conditions, smoke, or in visually-impaired and blind individuals, auditory perception becomes important. Acoustic information about the environment includes sounds radiated from sources, as well as reflections and reverberation in enclosed spaces in response to either external sound sources or self-produced sounds (e.g., mouth clicks), referred to as echolocation. Here, we investigated orientation and navigation in typical corridors based on acoustic cues only, using sighted humans without training and real-time virtual acoustics. Virtual sound sources and echo-location with predefined sounds as well as own vocalizations were used with the goal to identify suitable techniques for an acoustically augmented reality (AAR) based mobility aid. A hand-held acoustic pointer, rendering virtual sound sources at the closest wall in the pointing direction was best suited for orientation and navigation. For identification of the room shape, a performance similar to that obtained with a reference (visual) laser pointer could be achieved with the acoustic pointer in specific conditions. In addition to the above acoustic pointer, an AAR-based echolocation pointer with highly directed sound radiation, as achievable in the ultrasonic range, was additionally suggested.
Elastic metamaterials with gradings and their structural applications
Authors: Colombi Andrea
Published: November 2023

Graded designs allowing a progressive wave manipulation have been a cornerstone for the design of functional structures. Either based on local resonance, Bragg scattering or a mix of both, the performance of graded meta go much beyond the so-called bandgap, the original hallmark of elastic metamaterials. I will present different applications where elastic metamaterials featuring graded design have been studied and exploited for different purposes and scales. After introducing early proposals with EM and acoustic waves, applications on graded resonant metasurfaces will be showcased. These include both fundamental laboratory scale experiments but also civil and mechanical engineering-oriented applications for vibration energy harvesting and vibration suppression. I will then show the latest experimental efforts in modeling, optimising and 3D printing lightweight frame-based panels for structural engineering applications. These frames combine lightweight, bioinspired shapes with graded resonant elements and represent a promising design model for reimaging the design of structural members such as trusses, beams and shells integrating vibration control and application in structural engineering and architecture.
Asymmetric elastic wave scattering in elastic plates
Authors: Parker Samuel D. , Roettgen Daniel R. , Haberman Michael
Published: November 2023

Reciprocity is a fundamental principle that can be used to understand a wide range of wave phenomena. In reciprocal systems, the exchange of source and receiver between two points yields the same displacement at the receiver if the applied force at the source is the same for both configurations. The reciprocity principle enforces restrictions on the scattering matrix in an acoustic or elastic system, but these relationships are not obvious when multiple modes are present, particularly when modes are coupled due to the presence of asymmetric scatterers. In this talk, we apply the reciprocity principle in a simplified two-dimensional waveguide case to prove symmetry of the scattering matrix in passive systems with and without loss and establish requirements for asymmetric scattering. The requirements enforced by reciprocity and energy conservation are then generalized to Lamb modes of arbitrary order. Applications to acoustic and elastic metamaterial design and ultrasonic nondestructive evaluation are discussed. [Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA-0003525.]
Damping vibration of platform structure using modified acoustic black holes
Authors: Son Taehwan , Park Seongmin , Jeon Wonju
Published: November 2023

We propose waveguide absorbers (WGAs) to dampen structural vibrations of platforms supporting vibrating systems. The waveguide absorber is designed by modifing a spiral acoustic black hole (ABH) to improve its damping performance while saving installation space and weight. The proposed WGA absorbs the flexural wave propagating in a platform to its end, resulting in vibration damping in the platform. To maximize the damping capability of WGA, we analyze the structural intensity field of the platform and attach the WGA based on the intensity field. Numerical and experimental results show that large reductions of peaks in mobility are achieved using the WGAs, showing the possibility to utilize the WGA in practice.
Compositionality in intonation: Evidence from Greek
Authors: Arvaniti Amalia , Gryllia Stella
Published: November 2023

The autosegmental-metrical (AM) theory of intonational phonology posits that tunes are composed of independent elements, pitch accents and edge tones. However, configurational approaches remain popular, while AM relies on but cannot prove compositionality. We addressed this issue with a corpus of Greek wh-questions (N = 2135), elicited from 18 speakers using a discourse completion task that involved communicative situations resulting in rise-fall-rises or rise-falls. The rise-fall-rises are autosegmentally represented as a L* + H pitch accent on the utterance-initial wh-word, followed by a L- phrase accent and a H% boundary tone; the rise-falls are represented as L + H* L − L%. We applied functional principal component analysis (FPCA), a data-driven method that breaks down curves into components that capture independent modes of curve variation, and followed FPCA with LMEMs on the principal component coefficients. The pitch movement associated with each of the posited tonal elements was captured by a different PC: PC2 captured differences in the extent of the rise and the peak alignment of the pitch accent, PC1 differences in fall steepness, and PC4 the difference between a final rise and low, flat pitch. These results provide prima facie evidence for tune compositionality, since the differences are driven by the analysis not human annotation.
Development of a web application for recording and evaluating intonation in emotionally charged speech and singing
Authors: Kostek Bozena
Published: November 2023

The goal of the work is to develop a web application dedicated to evaluating intonation in emotionally charged speech and singing, recorded according to a given scenario. The starting point is a systematic literature review concerning existing corpora of emotionally charged speech and singing and their accessibility. Then, based on the review performed, assumptions of the web-based application are shown, along with the choice of emotions expressed and the words/texts to be recorded. The realized corpus is characterized by its multimodality. Four modalities are used in recordings, i.e., audio, video, Facial Motion Capture (FMC) system sensors, and a high-speed camera. There are versions of recordings in the form of the audio signal and video signal, respectively: 25 fps (Canon), 120 fps (Vicon), and 200 fps (GoPro), audio and video signals combined, and recordings from the FMC sensor system (C3D files). Important is the fact that the corpus contains recordings by professional and amateur actors who expressed neutral emotion, joy, sadness, and anger. The recorded speech and singing signals are uploaded to a server and then prepared for the intonation analysis employing artificial neural networks with a deep architecture.
Gestural timing in naïve listener imitation of Cantonese vowels
Authors: Havenhill Jonathan , Liu Ming
Published: November 2023

Studies of nonnative vowel production have analyzed sounds predominantly in terms of acoustics, while the underlying articulatory gestures, as well as their timing, remain understudied. This study examines nonnative production of backness and rounding contrasts in the Cantonese vowel sets /i y u/ and /ɛ œ ɔ/. 15 native Cantonese speakers and 15 native English speakers participated. Native English speakers read a list of English words containing the vowels [i u ɪ ʊ e o ɛ ɔ], and then imitated Cantonese words containing [i y u ɪ ʊ ɛœ ɵ ɔ], presented auditorily. L1 Cantonese speakers produced the same set of Cantonese words, presented orthographically. Dynamic acoustic, ultrasound, and lip video data were collected and analyzed using GAMMs. In L1 Cantonese, target tongue and lip positions are achieved at vowel onset and maintained throughout the vowel duration, yielding acoustically monophthongal vowels. In contrast, L1 English [u, o] exhibit peak rounding during the vowel offglide, while magnitude of tongue and F2 displacement vary according to consonantal context. Lip gestures show similar late timing in non-native imitations of Cantonese [y, u], yielding English-like F2 trajectories, although the two vowels differed in tongue position. These results suggest that acoustically non-native-like vowel productions may result in part from transfer of L1 gestural timing. [Work supported by Hong Kong RGC, No. 27614421.]
Inner speech processes for overt language production—Comparison of native English speakers and different proficiency learners of English
Authors: Asano Keiko
Published: November 2023

Inner speech refers to an internal process as a tool for internalized thinking besides actual overt speech. It plays an important role in analyzing and planning tasks occurring outside the world. Asano (2015) found that second language learners of English used different inner speech depending on their proficiency level. The roles of inner speech by native speakers and language learners also differ (Fernyhough et al., 2004). In addition, all people do not commonly use representations in the internal process. The dominance, such as speech language, written language, and visual imagery (Nakayama et al., 2021), to prepare for overt activities depends on the person. This research aims to determine what kind of inner speech or other processes will be prepared for the overt language activities between native speakers and second-language learners of English. The subjects for both groups answered which dominant is used as the inner preparation processes for overt language production by answering the survey questionnaires. Knowing the native speakers' inner speech process before the overt production activities will help the second language learners' overt language activities and suggest ideas for their language proficiency improvement.
Second formant transitions for acoustic analysis to differentiate among dementia types
Authors: Morris Richard J. , Oh Chorong , Franklin Parker
Published: November 2023

Recent evidence indicates that acoustic features associated with emotional prosody in speech may be an inexpensive, non-invasive method for differentiating among dementia types. In particular, frequency measures in the speech of people with dementia have been associated with listeners’ perception of emotional prosody. The purpose of this study was to determine if second formant (F2) transition information would enhance these differentiations. Prerecorded speech samples of Cookie Theft picture descriptions from 10 individuals with dementia of the Alzheimer’s type (DAT), 5 with vascular dementia (VaD), 9 with MCI, and 10 neurologically healthy controls (NHC) were obtained from the DementiaBank. Nine words that had initial obstruent consonants that occurred at least two times in each of the participant groups were selected for measurement. The F2 durations, extents, and slope were measured and analyzed. Across group comparisons revealed no pattern for F2 durations or extents. The fricatives had longer F2 durations than the plosives. Across word comparisons revealed significant differences across the consonant vowel combinations for all three measures. A group by word interaction occurred for the F2 slope with the VaD group exhibiting larger slopes than the other two groups.
Can a neurotypical actor align their speech acoustically to autistic speech patterns for roles in the media?
Authors: Todd Haley A.
Published: November 2023

Canonically autistic characters are represented in television, but these roles have often been filled by neurotypical actors. One criterion of autism diagnoses includes differences in speech, often described as “monotonic” or “robotic.” This study comparatively analyzed the speech of a neurotypical actor in an autistic role with that of autistic actors within neutral and emotional conditions. Acoustic measures included fundamental frequency (F0), duration, and intensity. Speech samples (n = 87) were collected from the television show Atypical and acoustically analyzed using PRAAT. Results showed that the F0 range, syllable duration range, and intensity range for the neurotypical actor in the autistic role was significantly more similar to neurotypical actors than autistic actors, though the change in syllable duration between conditions was significantly more similar to autistic actors. Additionally, a survey was developed in which participants listened to audio clips of the speech samples rating them on a Likert scale of “typical” to “atypical.” Results showed that the neurotypical actor in the autistic role was rated as atypical. Overall, it was concluded that neurotypical actors may not acoustically align with autistic actors, but they are successful in the perceived effect of atypicality based on the perception of their speech patterns by an audience.
Advancing hearing research with the NAL ecologically momentary assessment platform for real-world insights
Authors: Chong-White Nicky , Tagudin Joseph , Mejia Jorge
Published: November 2023

Ecological Momentary Assessment (EMA) is an invaluable tool for assessing people's behaviours and experiences in their natural surroundings. We have developed a smartphone-based EMA tool, called NEMA, that has contributed to over 10 research studies by providing meaningful real-world insights into how individuals with hearing loss interact with various hearing device technologies. By providing real-world perspectives that complement traditional lab-based tests, NEMA offers a more comprehensive understanding of everyday hearing and communication challenges. Its advanced features include cloud-connectivity, customisable surveys, cross-device acoustic feature measurements from the environment, and a back-end platform enabling real-time data monitoring and visualization. To derive vital insights from this rich data stream, advanced analytical methodologies are applied. However, there exist limitations with smartphone-based EMAs that can influence their overall effectiveness. We identify these constraints and discuss strategies to alleviate participant burden and increase task relevance. These initiatives aim to enhance compliance and diversify data collected. Current work involves integrating smartwatches and additional sensor technology into our next generation NEMA platform. This progression aims to facilitate a more comprehensive capture of diverse data sets, ultimately leading to a deeper understanding of individual auditory experiences.
Consonant and vowel rounding: Same acoustics, different visuals
Authors: Du Baichen , Pfiffner Alexandra , Johnson Keith
Published: November 2023

The phonological feature [±round] is normally associated with vowels, but this feature is also relevant for some consonant contrasts, such as the retroflex/non-retroflex sibilant contrast in Mandarin. One might assume that contrastive lip rounding would be the same gesture for consonants and vowels within language. However, because similar acoustic results can be achieved through different articulations, we hypothesize that the exact parameters of rounding might be variable for different segment types. An audiovisual production experiment was conducted with 30 Mandarin native speakers. Subjects produced 35 words with sibilants onsets (retroflexes /ʂ, ʈʂ, ʈʰ/, alveolars /s, ts, tsʰ/, palatoalveolars /ɕ, tɕ, tɕʰ/), and 40 words with high-front rounded/unrounded nuclei (/i/ and /y/). We found robust individual variation and that consonants and vowels were characterized with different visual properties: /y/ had small aperture in both vertical and horizontal directions and therefore smaller lip opening area than in /i/, while retroflexes had smaller horizontal but larger vertical apertures than alveolars or palatals. Acoustical consequences of rounding were similar: both spectral Center of Gravity and F1–F4 were lowered compared to unrounded counterparts, indicating that the same phonological feature may have multiple visual/articulatory correlates.