bluuebunny/crossref_metadata_2025 huggingface dataset:
Deep reinforcement learning-based framework for the design of broadband acoustic metamaterials
Authors: Shah Tristan A. , Amirkulova Feruza
Published: November 2022

This talk presents a general framework for discovering optimal designs of metamaterials with deep reinforcement learning (RL). In our previous research [1], we applied RL to acoustic cloak design and optimized the design parameters of a planar configuration of up to 12 cylindrical scatterers to minimize the scattering of an incident acoustic wave. The designs produced by RL algorithms are comparable and in some cases superior to those produced by fmincon solver. However, the challenge of finding an efficient approach for inverse design, is still in its emergent stage, requiring further modifications of these models and significant computational resources to increase the complexity of a design. This creates a significant challenge when attempting to enable model scaling since training times surge to unfeasible levels. We will discuss methods to counteract this challenge and present an RL-based framework for discovering optimal designs of meta-devices. We expanded our research [1] to large numbers of scatterers, and new designs with variable cylinder radii, position, and material. We noticed a dramatic improvement in the training times of RL agents due to the speed increase provided by the Julia programming language which accelerates episode runtimes 10-times compared to our previous models in python [1]. [1] T. Shah et al., “Reinforcement learning applied to metamaterial design,” J. Acoust. Soc. Am. 150(1), 321–338 (2021).
Meta-interface textures for increased frictional damping in elastic structures
Authors: Lawal Iyabo G. , Haberman Michael R.
Published: November 2022

The unique behavior of acoustic and elastic metamaterials results from engineered subwavelength material composition and geometry. Though there has been a profusion of metamaterial research over the last two decades, relatively little focus has been on the dissipation of vibro-acoustic energy. Most research on metamaterials for acoustic damping have focused on viscous or viscoelastic effects [1]. However, the design of interfaces within materials or at connecting surfaces between elastic structures to amplify micro-friction events due to the relative motion of contacting surfaces is of interest for the reduction of vibro-acoustic energy. Dissipation due to friction is best represented as a nonlinear constitutive response. Here, we report on the use of friction via meta-interface textures to create interfaces with elevated damping, leading to increased macroscopic dissipation. We employ the five-parameter Bouc-Wen model to describe the complex behavior at these interfaces and study the influence of subwavelength interface texture on the parameters of the friction model. This increased dissipation from this approach can be used to reduce structural vibrations and the transmission of acoustical energy in structural components. [1] C. L. Bacquet et al., “Metadamping: Dissipation emergence in elastic metamaterials.” Adv. App. Mech. 51, 115i–164, (2018).
Sonic black hole perforation study
Authors: Petrover Kayla
Published: November 2022

A powerful and under-explored method to target unwanted reflection and transmission of sound is the sonic black hole. It is the application of the acoustic black hole effect to acoustic waves. The interaction between the propagating acoustic wave and the power-law tapering geometry of the sonic black hole effectively reduces the wave speed, so that it never reaches the termination and, as a result, cannot be reflected or transmitted. One method to improve the overall attenuation created by the ideal phenomenon of the acoustic black hole effect is by adding perforations to the sonic black hole. This study explores the effect that varying the perforation size will have on the sonic black hole’s transmission loss and reflection coefficient across a frequency range of 0 to 5 kHz. Approved for Public Release Distribution Statement A.
Inverse design of direction independent metamaterials to control longitudinal and transverse waves
Authors: Ghodake Pravinkumar R.
Published: November 2022

Direction-independent elastic metamaterials that can control longitudinal and transverse elastic waves independently for nonlinear ultrasonic testing are designed using an inverse design approach by defining the time-dependent inverse problem. Forward finite element wave propagation models are solved inversely as multiple multi-objective design optimization problems using gradient-free algorithms. Suppressing the 2nd harmonics (2f) generated due to instrumentation during nonlinear ultrasonic testing is obtained by keeping the first objective as reducing only second harmonics without concentrating on the amplitude of the 1st harmonics, which is a necessary condition for ultrasonic testing, whereas almost all the inversely designed metamaterials take care of this condition due to intelligent selection of material combinations. The second objective is defined as reducing error due to the difference between a pulse with 1st (f) and 2nd (2f) harmonics and a delayed pulse with 1st harmonics (f), as well as maximizing the power of the output pulse by defining min-max multi-objective optimization problems.
A cross-linguistic study of audio-aerotactile perceptual integration using voicing continua
Authors: Saito Haruka , Ménard Lucie , Tiede Mark , Whalen D. H.
Published: November 2022

Previous studies on multimodal integration in speech perception have found that not only auditory and visual cues, but also tactical sensation—such as an air-puff on skin that simulates aspiration—can be integrated in the perception of speech sounds (Gick & Derrick, 2009). However, most previous investigations have been conducted with English listeners, and it remains uncertain whether such multisensory integration can be shaped by linguistic experience. The current study investigates audio-aerotactile integration in phoneme perception for three groups: English, French monolingual and English-French bilingual listeners. Six step VOT continua of labial (/ba/—/pa/) and alveolar (/da/—/ta/) stops constructed from both English and French endpoint models were presented to listeners who performed a forced-choice identification task. Air-puffs synchronized to syllable onset and applied to the hand at random increased the number of ‘voiceless’ responses for the /da/—/ta/ continuum by both English and French listeners, which suggests that audio-aerotactile integration can occur even though some of the listeners did not have aspiration/non-aspiration contrasts in their native language. Furthermore, bilingual speakers showed larger air-puff effects for English stimuli compared to English monolinguals, which suggests a complex relationship between linguistic experience and multisensory integration in perception.
Auditory free classification of gender diverse speakers
Authors: Merritt Brooke , Bent Tessa
Published: November 2022

A central issue in speech perception is how listeners resolve variability. Gender diversity presents an opportunity to examine how listeners learn and represent one dimension of sociophonetic variability arising from an evolving social category, speaker gender. To assess listeners’ perceptual organization of speaker gender, recordings were obtained from 30 cisgender (15 men, 15 women) and 30 transgender (1 agender, 15 non-binary, 7 transgender men, 7 transgender women) speakers. In an auditory free classification paradigm, listeners categorized speakers reading the same or unique sentences by perceived general similarity and gender identity. Multidimensional scaling revealed gradient organization of speaker gender with masculinity/femininity and gender prototypicality as the two most salient dimensions. Cluster analyses showed fewer perceptual speaker groups and attention to fewer indexical speech features when speakers produced unique sentences. Instructions to explicitly categorize speakers by perceived gender identity substantially simplified the hierarchical structure of speakers and shifted listeners’ attention towards masculinity/femininity over gender prototypicality. Results suggest that listeners engage in fine-grained, multivalent analysis of speaker gender that cannot be adequately captured by a “male” vs “female” dichotomy. Assumptions of a gender binary in speech communication research may require a critical re-examination to accommodate multidimensional and gradient representation of speaker gender.
Examining the effectiveness of multi-talker training on morphophonological learning
Authors: Drake Shiloh , Preligera Isabel , Baese-Berk Melissa M.
Published: November 2022

This study explores how auditory stimuli from multiple talkers affects learning of morphophonological alternations in an artificial grammar. Hearing words from multiple voices creates more robust lexical representations (e.g., Davis & Gerken, 2013, 2014; Rost & McMurray, 2009, 2010) and aids generalization to new grammatical structures (Gonzales et al., 2018) and accents (Baese-Berk et al., 2013; Bradlow & Bent, 2008). In ongoing work, participants hear either four different voices or four repetitions from the same voice when learning singular and plural forms in two artificial grammars. As found previously, we expect that hearing from multiple talkers will result in more accurate responses when participants are tested when compared to the participants who heard the same number of repetitions from the same voice. Furthermore, we expect a more pronounced difference in accuracy between the two talker conditions in the Arabic-like grammar than in the English-like grammar.
Perception of Bengali stops: The role of Markedness
Authors: Sarkar Sreeparna
Published: November 2022

Marked segments, by definition, bear additional properties with respect to unmarked ones, in principle requiring more articulatory effort. At the same time, however, these additional properties may make marked sounds more audible and identifiable. This study investigates how voicing and aspiration, as mark properties, affect the perception of Bengali stops, exhibiting the common Indo-Aryan four-way contrast: voiceless unaspirated, voiceless aspirated, voiced unaspirated, voiced aspirated. Specifically, I test whether the properties of voicing and aspiration result in improved perceptibility of stops separately and whether their combination shows an increased cumulative effect.50 native Bengali speakers each listened to 270 CV stimuli, the first syllable extracted from real 3-syllable words. The C was one of the four stop types; the V was /a/. The participants identified the syllable they heard by selecting one of six options (the four stops and two fillers) shown in Bengali script. The results reveal significantly higher perceptual accuracy in the stops marked by voicing vs. voiceless categories (83.78% vs 80.48%, respectively) and higher perceptual accuracy of aspirated versus unaspirated stops ( 84.04% vs 78.49%, respectively). The two “marks” combined in voiced aspirated stops do not increase accuracy more than each alone (83.89%) but overall differ most from plain unaspirated stops (75.8%).
The perception-production link in two types of cross-language mismatches
Authors: Mazet Corentin
Published: November 2022

Previous data on the perception-production link have allowed for a variety of analyses, from the traditional straight-forward correlation between the two competencies (Flege 1995) to more nuanced interpretations of the data (Shultz et al. 2012). Where the traditional approach suggests that better perception is linked to better production, recent work challenges this conclusion and reveals a complex relationship. Here, we compare native French speakers' perception and production of English diphthongs (/a⌢ʊ/, /e⌢ɪ/ and /a⌢ɪ/) and interdental fricatives (/θ/ and /ð/). These specific segments were chosen as they are absent from the French phonological system, they show identifiable realizations, and they behave differently from one another. The competence in perception and production of 21 native hexagonal French speakers were collected through a repetition task and an AXB matching task. Consistent with Flege (1995), we show that for any given segment, greater perception accuracy predicts greater production accuracy. However, at the speaker level, the relationship between the two competences is a complex one, as the link between perception and production is not apparent in our data. These results would confirm the traditional approach at the segment level, but individual variation might prevents us from seeing it at the speaker level.
Acoustic cues to the perception of Danish stød
Authors: Pena Jailyn M.
Published: November 2022

This study examines the effect of F0 and creak (raspiness) on Danish stød perception. Stød is typically characterized by high fundamental frequency (F0) at the beginning of the syllable and low F0, often with creaky phonation, at the end of the syllable (Fischer-Jørgensen, 1989). However, it is not clear how these acoustic cues, high F0 at rhyme onset, low F0 at rhyme offset, and creak, contribute to the percept of stød for listeners. A nonce word ABX task and a perceptual rhyming task were conducted. Results from the ABX task indicate that nonce words with high-mid or high-low F0 contours and added raspiness (Corretge, 2012) or a sustained high F0 with or without raspiness were more likely to be considered the “same” as naturally produced nonce words with stød. In the rhyming task, nonce words with high F0 and raspiness were significantly more likely to be considered as rhyming with a naturally produced real word with stød for all tonal contours tested. Overall, the results indicate that both high F0 onset{Citation} and creaky phonation contribute to the stød percept. Furthermore, both cues were almost always needed to increase stød responses in both tasks, suggesting little evidence of cue trading.
Extraction of indexical and linguistic information as a function of duration in the older population
Authors: Smith David R. , Guerrini Chiara
Published: November 2022

When someone speaks information is present in a number of forms. The most obvious information is what the person has said (linguistic message). However, indexical information relating to the physical characteristics of the speaker is also embedded in the speech sound wave and influence judgements about the speaker such as whether they are a man or woman. Previous research studied how vowel recognition and speaker-sex discrimination information accumulates as a function of speech duration in the normal-hearing young population [D. R. R. Smith, Acta Psychol. 148, 81–90 (2014)]. We extended this research by investigating the build-up of linguistic and indexical information in the older population (Mage 72-years). Psychometric functions were collected plotting percent correct speaker sex discrimination and vowel recognition, as a function of vowel duration (5–40 ms), for older listeners compared to younger listeners (Mage 22-years). Older listeners’ performance on both tasks was markedly impaired compared to younger listeners’ performance. It is argued that deficits in the accumulation of indexical information at short durations might partially underlie the problems the older population experience in understanding speech and following conversations, especially where who is speaking is constantly changing such as in a noisy restaurant where several people are conducting a conversation.
The effect of the number of items on the reliability of speech intelligibility results for WIPI test
Authors: Flaherty Mary M. , Nudelman Charlie , Bottalico Pasquale
Published: November 2022

The Word Intelligibility by Picture Identification (WIPI) test is a widely used test to assess speech recognition in the pediatric population. The test consists of four 25-item monosyllabic word lists that are within the vocabulary of preschool children. The child responds to each item by selecting one of six pictures on a page, one being the test item. The purpose of this study was to understand if the final score of a test can be obtained accurately with a fewer number of items in a word list. Ten monolingual children (8–12 yrs) with normal hearing were tested using a revised version of the WIPI (2nd ed.), presented in a soundbooth over headphones. Target words were presented in a classroom-noise masker at a fixed signal-to-noise ratio. The results suggest that a minimum of seven items is needed to obtain results that are not statistically different from the one complete test (25 items). This implies that the WIPI can be administered in a shorter time period, which could be particularly beneficial when testing multiple acoustic conditions on experimental tasks.
Perceived linguistic marginalization and speech intelligibility in a racially diverse cohort of talkers
Authors: Tripp Alayo , Munson Benjamin
Published: November 2022

Studies suggest that the listeners’ social categorizations of talkers may mediate how intelligible those talkers’ speech is perceived to be (Babel & Russel, 2015; McGowan, 2015; Kutlu et al., 2021; Kutlu et al., 2022; McLaughlin et al., 2022; Yi et al., 2013). One interpretation of these findings is that talkers’ attitudes toward different racialized groups affects intelligibility. Studies have used implicit association tests (Greenwald et al., 1998) to test this hypothesis. Some studies have found that negative implicit associations with specific groups (i.e., Asian Americans) predict intelligibility (Yi et al.) while others have found no association (McLaughlin et al.). In this presentation, we present a new tool to examine listeners’ attitudes toward different racialized groups. The Perceived Linguistic Marginalization Scale (PLMS, based on the Perceived Societal Marginalization Scale, Bulwerk et al., 2022) directly examines individuals’ beliefs about the significance of language variation in marking groups of people as marginalized. In this poster, we present the results of 242 participants’ performance on the PLMS. We examine whether performance on the PLMS predicts audio-only and audio-visual intelligibility of 28 racially diverse talkers in a speech intelligibility experiment. Data collection is complete and analysis is ongoing. [Funded by NIH grant R21 DC018070]
Artificial intelligence in music production: Controversy and opportunity
Authors: Reiss Josh
Published: November 2022

Could a robot replace the sound engineer? Recent years have seen the emergence of intelligent systems aimed at algorithmic approaches to autonomous mixing and mastering of audio content. This talk will give an overview of the field, explanations and demonstrations of the technology, and a discussion of the challenges and directions currently being explored. We further discuss the role of artificial intelligence in audio production, and what it means for sound engineering in future.
Concert hall reputations versus reality over time, for better or worse?
Authors: Conant David A.
Published: November 2022

The acoustical reputations of many concert halls provide a curious study of human nature as illuminating as their acoustical attributes. This paper reveals how the reputations of 7 prominent halls that opened between 1880 and 1973 have morphed and offers conjecture as to the reasons. Discussed briefly, are Troy Music Hall (1875), Carnegie Hall (1891), Boston Symphony Hall (1900), Philharmonic Hall (1962), and Phoenix Symphony Hall (1973) among others. Each has undergone renovations and met with varying public reaction.
The Myriad of metrics in medical ultrasound imaging; Which should we use?
Authors: Rindal Ole M.
Published: November 2022

Software beamforming allows flexible adaptive beamformers with great popularity and exponential growth in the number of papers published. Software beamforming can be a blessing to the image quality since access to raw channel data allows algorithms that better exploit the data. However, software beamforming can also be considered a curse, since the flexibility leads to non-linear algorithms that invalidate the conventional metrics used to evaluate the image quality. A review of the contrast metrics used in ultrasound imaging shows no consensus on the metrics used in the research literature. Multiple metrics exist and different types of data, in different scales, from different stages of the processing chain, are used as input to the metrics.We have demonstrated that many adaptive algorithms alter the dynamic range of the ultrasound images, effectively breaking the conventional metrics both for contrast and resolution. Therefore, we have introduced a new improved contrast metric, the generalized contrast-to-noise ratio (gCNR) immune to dynamic range alternations. The gCNR can be estimated on all kinds of images, regardless of compression, scale, or output units. A major drawback of the conventional contrast metrics, as well as the gCNR, is that they require localization of specific regions and targets in the image. Such objects can be difficult to identify in in-vivo images. We recently introduced Global Image Coherence (GIC), as an in-vivo image quality metric that does not require any identified regions.
A mathematical perspective of ultrasound image representations and image quality criteria
Authors: Hyun Dongwoon
Published: November 2022

What is an ultrasound “image”? Where an engineer or physicist may see a quantitative map of physical properties, a physician may see qualitative anatomical features and pathologies. In the past, each image type was evaluated appropriately within its respective context: quantitative image quality was measured with criteria like the contrast-to-noise ratio (CNR), and qualitative images underwent dynamic range transformations to optimize human perception of contrast. Recent non-linear beamforming methods have blurred this line: the produced images are transformed like qualitative images but evaluated with quantitative criteria like CNR. Here, we identify the mathematical flaws in reasoning and suggest rigorous alternatives.An image assigns values to spatial coordinates. Let X denote the set of all possible image values. The mathematical structure endowed on X determines the set of equivalence-preserving transformations. For instance, qualitative images treat X as a general topological space, where images are equivalent under homeomorphisms of X (dynamic range transformations). Quantitative images treat X as a metric space and have fewer equivalence-preserving transformations. These structures determine when criteria like contrast, CNR, generalized CNR, and spatial resolution can be used. To extrapolate these criteria to other contexts, one must use relevant structure-preserving isomorphisms (e.g., histogram matching to preserve information content).
A spatiotemporal coherence-based approach for optimizing transcranial ultrasound imaging sequences
Authors: Vienneau Emelina P. , Byram Brett
Published: November 2022

Functional ultrasound imaging (fUSI) is a promising new neuroimaging modality for preclinical and niche clinical applications, but translation to noninvasive use in adults remains unresolved due to skull-induced image degradation. Attenuation leads to low signal-to-noise ratio (SNR), whereas clutter leads to low signal-to-clutter ratio (SCR). Coded excitation or microbubbles could increase SNR, whereas adaptive beamforming, phase aberration correction, or harmonic imaging could increase SCR. However, it’s unknown how the relative importance of noise and clutter varies across demographics. To optimize a demographic-specific transcranial imaging sequence, a tool to measure SNR and SCR and assess the impact of sequence modifications is needed. We propose using a spatiotemporal coherence technique [DOI:10.1109/TUFFC.2022.3152717] to measure SNR and SCR with coded excitation [DOI:10.1109/IUS46767.2020.9251650] for different parameters like code length and voltage. We conducted a transcranial imaging study in five volunteers (median age 25, Caucasian, three males, two females) and used focused M-Mode data to measure SNR and SCR. With optimally chosen parameters, we improved SNR by 16.87 ± 2.18 dB and 13.18 ± 1.14 dB with 65 bit and 25 bit codes without introducing additional clutter (SCR gains were −0.29 ± 0.67 dB and 0.13 ± 0.84 dB with 65 and 25 bit codes). These improvements will enable clinical translation of transcranial fUSI.
High frequency stochastic acoustic wavefront propagation and joint ocean-acoustic inference: The GMM-DO wavefront
Authors: Bhabra Manmeet S. , Ali Wael H. , Lermusiaux Pierre F.
Published: November 2022

In marine applications, the value of accurate modeling and learning for stochastic acoustic propagation in uncertain ocean environments cannot be overstated. In this work, we derive stochastic theory and schemes for (i) modeling of high frequency acoustic propagation in uncertain ocean environments and (ii) joint Bayesian assimilation of ocean-acoustic measurements to infer fields, parameters, and uncertain model functions. We first obtain the Dynamically Orthogonal (DO) wavefront equations to solve for the stochastic extension of the Liouville Equation that governs the dynamics of acoustic wavefront in an augmented phase space. These DO wavefront equations provide the prior for the Gaussian Mixture Model—DO (GMM-DO) filter that completes joint physics-acoustics Bayesian inference using sparse observations. Specifically, given a set of receivers, the Eulerian nature of the DO wavefront equations allows for the efficient extraction of arrival time prior probability distributions. The GMM-DO Waverfront filter then combines these joint priors with arrival time measurements using Bayes rule, jointly inferring environmental properties (e.g., unknown source location and/or sound speed field), the acoustic wavefront distribution, and the arrival time distribution itself. We evaluate results using high-frequency applications, illustrating the estimation of mean fields and properties, but also of probability density distributions and model parameterizations.
DJ Prof: Reflections on teaching
Authors: Wage Kathleen E.
Published: November 2022

In a short-lived career as a cartoonist for Acoustics Today [Summer 2016], I sketched DJ Prof, an acoustics professor who mixes multiple modes of instruction to engage and excite students. DJ Prof illustrates the concept of active learning, which Freeman et al. called the “preferred empirically validated teaching practice” [PNAS, 2014]. Numerous studies show that active learning courses improve student learning, increase retention rates, and reduce performance gaps in STEM for economically disadvantaged students and females in male-dominated classes. This lecture reflects on my evolution as DJ Prof using examples from acoustic signal processing courses. I will provide a brief overview of the literature on active learning, share a few favorites from my pedagogical playlist, and highlight open questions for the acoustics education community. The session will include interactive exercises. Please bring an open mind, a sense of humor, and a willingness to meet the people sitting near you.
European policy for port noise control and mitigation
Authors: Schenone Corrado , Gaggero Tomaso , D'Alessandro Francesco , Baldinelli Giorgio , Schiavoni Samuele , Borelli Davide
Published: November 2022

Port noise affects the development of harbour cities on EU shores. Tourism, goods transportation and passenger traffic are increasingly limited by noise impact on port cities, which annoys residents and disturbs the sleep of the exposed population. Therefore, the EU has promoted coordinated actions and programmes aiming to control and reduce port noise in the Europena area. Port authorities, shipping companies, public orgnizations, shipyard owners, terminal operators, municipalities are developing an ambitious programme pursuing harbour noise control. Several projects have been funded to develop a recovery strategy and promote collaboration between port stake-holders. These projects cover different aspects of port noise in the framework of a coordinated policy over a specific area of the European shores. Each project addresses a specific goal, in accordance with an overall coordinated strategy: RUMBLE deals with large commercial ports, DECIBELwith small touristic harbours, LIST with noise from traf-fic generated by the ports, MONCUMEN with measurements and characterisation, REPORT with modelling and impact prediction, TRIPLO with reaction of the exposed population. The outcomes of these projects are expected to create a decisive turning point, both at territorial and technical level, with relevant benefits for the whole Europe.
Coherent infrasound generation using an air-propane burner
Authors: Smith Chad M. , Gabrielson Thomas B. , Merchant B. J.
Published: November 2022

An invaluable tool in characterization of any receiver, propagation path, or detection system, is a source with known and repeatable signal characteristics. This talk will discuss development and evaluation of a coherent (non-explosive, periodic, with controlled duration) infrasound source with frequency capabilities in the sub-hertz to several hertz band. Design of a practical sound source within this band is a difficult engineering challenge. The simple source equation, which will govern any portable human-fabricated infrasound source due to the long wavelengths, shows this fundamental difficulty. As frequency decreases volume displacement must increase by the squared inverse factor of frequency in order to maintain an equal pressure amplitude at equal range. For this reason, the authors investigate utilizing the high energy density available in gas combustion to periodically displace large volumes of air within the open atmosphere. Prototype testing has verified the capability of generating continuous signals at a fundamental frequency of 0.25–1.5 Hz in the farfield—or ranges from the source where pressure and particle velocity are roughly in-phase. Harmonics of this fundamental are also generated throughout the 0.25–4.0 Hz band with reasonable signal-to-noise ratio. Development of the infrasound source prototype as well as experimental testing and results will be discussed.
On the correlation between microbaroms and microseism, and what can we learn from it
Authors: Averbuch Gil , Assink Jelle D. , Arrowsmith Stephen
Published: November 2022

Wind-driven ocean swells act as the source for both atmospheric microbaroms and solid earth’s microseisms. Since they share the same source, microbaroms and microseisms’ power are expected to display similar characteristics in collocated seismo-acoustic stations. Any deviation from this hypothesis can provide information about the source mechanism, the state of the atmosphere, and the seismo-acoustic energy partitioning at the source region. In addition, prolonged observations may show evidence of climatic trends. This study presents a multi-year (∼20 years) comparison between microbaroms and microseisms’ power in collocated seismo-acoustic stations. Initial results show that sporadically, microbaroms and microseisms’ power can be in and out of phase up to 180 degrees. Moreover, stations’ spatial location seems to affect the observations and will be further investigated.
Impact of explosion-generated acoustic waves on atmospheric layers
Authors: Sabatini Roberto , Inchin Pavel A. , Pineyro Benedict , Snively Jonathan B.
Published: November 2022

Explosive events, such as artificial or accidental explosions, and volcanic eruptions, among others, generate low-frequency acoustic waves that propagate through and perturb atmospheric and ionospheric layers (e.g., the hydroxyl and oxygen airglow layers, the sodium layer, and the ionospheric D-region). The subsequent disturbances (i.e., airglow emission intensity, sodium or other minor species density, or electron density fluctuations) are potentially detectable by optical or radio remote sensing methods. Understanding and quantifying the impact of acoustic waves on atmospheric layers are, therefore, crucial steps for establishing detectability thresholds (e.g., relative to source scales and effective yields). In this work, we investigate the propagation of upwardly-traveling acoustic perturbations induced by 1t to-1 kt of TNT-equivalent ground explosions and their signatures on different atmospheric layers. Specifically, we estimate the amplitudes and periods of the induced fluctuations of hydroxyl, sodium, and electron densities at mesospheric through lower-thermospheric altitudes. This work investigates the potential of such layers to serve as sensors for characterizing lower-atmospheric explosive events and the complementarity of such indirect measurements with direct sensing, e.g., of pressure fluctuations in situ.
Numerical modeling of T-wave generation in a horizontally inhomogeneous ocean
Authors: Godin Oleg A. , Cristini Paul , Bottero Alexis , Monteiller Vadim
Published: November 2022

T-waves are generated by earthquakes and travel horizontally with the speed of sound. They are the most common earthquake sounds in the ocean and make strong contributions to the ambient sound field. However, the mechanisms of their generation remain poorly understood. Recent theoretical paper [O. A. Godin, J. Acoust. Soc. Am. 150, 3999–4017 (2021)] argues that scattering of ballistic waves from the earthquake focus by the ocean surface is a strong source of T-waves, which should be considered on par with previously identified generation mechanisms of wave diffraction on large bathymetric features and scattering by the rough seafloor. This paper compares the T-waves due to ocean surface roughness and a seamount in deep water. 3-D surface scattering and wave interaction with large-scale bathymetric features are modeled rigorously using time-domain spectral-element code SPECFEM3D, with the ocean surface being shaped by wind waves and sea swell and a large seamount located off the earthquake epicenter. These simulations are complemented by a normal-mode code to propagate the sound field from the generation region to long ranges. A mode projection technique is developed to efficiently couple SPECFEM3D to the normal mode code. The two mechanisms are found to generate T-waves of comparable amplitudes.
Infrasonic horn and ribbon microphone
Authors: Muir Thomas G. , Wilson Preston S.
Published: November 2022

Infrasound measurements normally utilize seismic sensors (geophones and accelerometers) with deployment on the ground surface, the seafloor, ice packs, etc. Here, the infrasound propagating in an overlying fluid medium such as air or water, interacts with the solid medium, thereby imparting its signature. These sensors primarily detect ground motion in terms of the particle velocity or acceleration (force) of the ground in contact with the sensor. Pressure microphone sensing of infrasound in the atmosphere has also been explored. We examine here the atmospheric sensing of infrasound, using the well-established technique of the ribbon microphone, which employs a thin metallic ribbon, suspended between two magnets to detect the particle velocity of the sound propagating in a fluid medium. Movement of the ribbon in the sound field generates a voltage according to Faraday’s Law. Although ribbon microphones are fixtures in audio band acoustics, their application to infrasound is not, and is explored here. Ribbon microphones made from suspension of conductive mylar tape between two neodymium magnets have been fabricated and tested in an infrasound band around a few Hertz. The results show a viable approach to vector sensing in this band. Work supported by ARL:UT Austin.
Estimating the contribution of central noise from composite performance across multiple tasks
Authors: Venezia Jonathan H. , Whittle Nicole , Leek Marjorie R. , Herrera Ortiz Christian
Published: November 2022

According to signal detection theory, the ability to detect a signal is limited only by internal noise, which comprises peripheral and central sources. Here, we develop a statistical approach to parse central from peripheral noise. Fifty-two Veterans (mean age = 47.8, range = 30–60) with normal or near-normal hearing performed AXB discrimination for several temporal processing tasks: gap duration discrimination, forward masking, frequency modulation detection, and interaural phase modulation detection. After training, a single adaptive run (40 reversals) was completed for each task. Subjects also completed speech-in-noise testing (“Theo-Victor-Michael") with four masker types (48 trials ea.): speech-shaped noise, speech-envelope modulated noise, one and two competing talkers. Composite speech performance was estimated using principal component analysis. Bayesian hierarchical regression was used to estimate two-parameter psychometric functions (threshold, slope) simultaneously for all temporal tasks and subjects. Crucially, fixed (group-level) thresholds were estimated per task but only a single random (subject-level) intercept was estimated (mean across-task deviation from the group thresholds). We assume central noise is the primary factor limiting across-task performance. The principal speech scores were entered as regressors on this “central threshold.” Indeed, central threshold was correlated with the principal speech scores, suggesting that central noise limits temporal processing and speech-in-noise.
Skin conductance during remote collaborative communication under noisy, reverberant and delayed communication transmission conditions
Authors: Rawool Vishakha
Published: November 2022

This study, which is part of a larger study, was designed to monitor skin conductance during remote collaborative communication. Ninety (45 men and 45 women) participants were divided into 30 teams with three members in each team. Each team built different LEGO models under three communication transmission delay conditions in the following order: No delay, 750 ms delay and 5000 ms delay. One individual served as the LEGO builder, who did not have the instruction manual. The remaining two team members provided instructions for building the models. Participants were in separate rooms and communicated via earphones. Background white noise (50 dB SPL) was introduced in the ear canals and reverberation was applied to the transmitted communication. Participants were fitted with Empatica E4 wristbands. The ANOVA revealed that the Sum of non-specific skin conductance response (NS-SCR) amplitude/minute was significantly reduced in the 5000 ms delay condition compared to the No delay and 750 ms delay conditions with a medium effect size. These results suggest that participants tend to adapt to the task yielding reduced stress in the last delay condition. Acknowledgement: Graduate students Sydney Osbarn and Melissa Reyes assisted in data collection. Sydney Osbarn also assisted in pre-processing the data.
Medial olivocochlear reflex strength in ears with low-to-moderate annual noise exposure
Authors: Lee Donguk , Goettl-Meyer Morgaine , Lewis James D.
Published: November 2022

Recent work suggests enhanced medial-olivocochlear reflex (MOCR) strength in noise exposed individuals. The current study aimed to replicate this finding using stricter signal-to-noise ratio (SNR) criteria in MOCR estimates and a larger subject population. Ninety-eight normal-hearing young adults participated. The MOCR test included measurement of click-evoked otoacoustic emissions (CEOAE) with and without contralateral noise. MOCR-induced magnitude and phase shifts were calculated. The MOCR test was performed twice to provide a within-session replication. Annual noise exposure history was estimated using the Noise Exposure Questionnaire. Annual noise exposure was not a statistically significant predictor of the MOCR-induced CEOAE magnitude shift. A statistically significant negative correlation was found between annual noise exposure and the MOCR-induced CEOAE phase shift. A significant negative correlation was also identified between annual noise exposure and CEOAE level. Results suggest diminished MOCR strength in noise-exposed individuals. This finding contrasts with recent work using similar methods. Compared to earlier work, the current study relied on higher OAE SNRs in MOCR estimates and sampled a larger population of subjects with broader noise exposure histories. The concurrent finding of reduced OAE levels in noise exposed individuals suggests acoustic trauma may be an underlying cause of reduced MOCR strength.
Evaluation omn three-forced choice audiometry for hearing threshold measurement
Authors: Ashilah Naomi , Syahadhatin Yuniar , Nadiroh Ainun , Purnami Nyilo , Arifianto Dhany
Published: November 2022

Common audiometry used in hospitals uses the 2AFC (Two Force Choice) method, which has a large and predictable bias. In this research, the three-force choice (3AFC) method is proposed for a smaller bias to measure hearing threshold. A hearing test was conducted on 50 participants. Three kinds of audiometric tests are used, including conventional, Pychoacoustic, and portable audiometry. A validation test was carried out by comparing the results of Pychoacoustic and portable audiometric tests using the 3AFC method with the golden standard (conventional audiometry). Pychoacoustic audiometry is unable to display the hearing threshold value in accordance with that shown by golden standard audiometry (conventional audiometry), where the mean value is 18.0–43.0, and standard deviation is 7–12 . However, the portable audiometry test is able to display a threshold value that is close to the golden standard audiometric results, with a mean value of 11—28, and standard deviation value of 3—6 . Based on the statistical calculation of the Wilcoxon test and Bonferroni's correction, it can be concluded that data collection using Pychoacoustic outdoors and Portable in the relevant room has performance that is parallel to the golden standard test (sig value >0.05).
Effects of prosodic structure on the temporal organization of speech and co-speech gestures
Authors: Lee Yoonjeong , Krivokapić Jelena , Purse Ruaridh
Published: November 2022

Although many studies have observed a close relationship between prosodic structure and co-speech gestures, little is understood about cross-modal gestural coordination. The present study examines the relationship between articulatory and co-speech gestures at prosodic boundaries and under prominence, focusing on non-referential manual and eyebrow beat gestures in Korean, a language in which co-speech gestures are virtually unexplored. This study hypothesizes that prosodic structure systematically governs the production of both speech and co-speech gestures and their temporal organization. Multimodal signals of a story reading were collected from eight speakers (5F, 3M). The lips, tongue, and eyebrows were point-tracked using EMA, and the vertical manual movements obtained from a video recording were auto-tracked using a geometrical centroid tracking method. Measurements taken included the duration of intervals from the timepoint of concurrent beat gesture onset and target to 1) consonant gesture onset and target, 2) vowel gesture onset and target, 3) pitch gesture (F0) onset and target, and 4) phrasal boundaries. Results reveal systematic inter-articulator coordination patterns, suggesting that beat gestures co-occurring with speech gestures are recruited to signal information grouping and highlighting. The findings are discussed with reference to the nature of prosodic representation and models of speech planning. [Work supported by NSF.]
Monitoring laryngeal and respiratory adjustments during voice production using a simulation-based voice production inversion neural network
Authors: Zhang Zhaoyan , Kegelmeyer John
Published: November 2022

Previously we reported a simulation-based neural network for estimating vocal fold properties and subglottal pressure from the produced voice. In this study, we evaluate the feasibility of using this neural network to monitor laryngeal and respiratory adjustments during speech production in individual speakers. Acoustic and aerodynamic data were collected in human subjects while producing utterances of five repetitions of the syllable /pa/ at different loudness levels. Voice features were then extracted and used as input to the neural network to estimate changes in vocal physiology and subglottal pressure. The results showed all subjects increased the subglottal pressure and vocal fold adduction when producing a louder voice, although the degrees of laryngeal and respiratory adjustments were speaker-specific. The neural network also estimated on average shorter and thinner vocal folds in female subjects than male subjects. These results demonstrate the potential of this neural network toward monitoring and identifying potentially unhealthy vocal behaviors.
Evaluating the impact of intermediate and deep sound speed uncertainty in the Irminger Sea on acoustic situational awareness
Authors: Bhatt EeShan , Weller Robert A. , Baggeroer Arthur B.
Published: November 2022

High-resolution observations from moorings and transect data can provide new insights into ocean structures, their variability, and the downstream effects on acoustic operations. Previously, we established a framework to maintain optimal communication and navigation for small-scale, under-ice operations that focused on spatio-temporal variability in the upper water column and around an autonomous underwater vehicle. However, mid- and deep-water sound speed fidelity are crucial for larger operations that exploit convergence zone ranging. The Irminger Sea is a useful case study for understanding how sound speed uncertainty, whether from partial data or models, obscures the informational content from acoustics. Generally, the density gradient dominates the sound speed at depth. In the Irminger Sea, hydrographic variability comes from the advection of different water masses through the region at all depths and also from water mass modification by local air-sea interaction. Instead of a uniform gradient as a result of hydrostatic loading, a shifted gradient in the mid-water column and a negative gradient near the bottom are often observed in mooring and transect data. This talk presents initial results for understanding the impacts of the environment through the lens of impact on acoustic propagation. [Work supported by the Office of Naval Research]
Joint ocean physics-acoustics inversion and mutual-information based experiment design in realistic ocean fields
Authors: Ali Wael H. , Mirabito Chris , Haley Patrick J. , Lermusiaux Pierre F.
Published: November 2022

Reliable acoustic exploration and navigation in the ocean requires precise knowledge of the environmental fields (e.g. ocean physics, bathymetry, seabed) and acoustic parameters (e.g. source location and frequencies). However, such knowledge is typically incomplete due to the sparse and heterogeneous observations, and to the complex high-dimensional multiscale dynamics. In this work, we use our stochastic Dynamically Orthogonal Parabolic Equation (DO-ParEq) framework to: (i) model the ocean environment uncertainties computed from a large realistic ocean ensemble forecast, and (ii) predict the resulting stochastic acoustic fields and their probability distributions. We then employ new nonlinear Bayesian learning algorithms that use Gaussian Mixture Models to assimilate ocean-acoustic measurements and jointly infer the unknown properties of the ocean environment, the bathymetry, the acoustic field and parameters, and even the model parameterizations themselves. We showcase the developed techniques in realistic data-assimilative sea experiments in the New York Bight Region and the Mediterranean Sea. Finally, we demonstrate the impact of selecting measurement locations using a mutual-information-based algorithm that maximizes the information content in the learned fields based on the measurement constraints.