bluuebunny/crossref_metadata_2025 huggingface dataset:
Calculation of sound transmission parameters for wood-frame and mass timber assemblies
Authors: Smart Jason
Published: July 2024

While much of it is proprietary, a significant amount of the data from sound transmission tests performed on mass timber assemblies has been shared in the public domain. Previous efforts at using this data to develop empirical models for estimating single-number ratings of floor assemblies have been limited in scope and have not always yielded accurate results. In order to provide an additional means of demonstrating compliance with code requirements, the American Wood Council (AWC) has developed calculation-based analysis approaches for deriving STC and IIC ratings for assemblies constructed with wood-based framing and mass timber. As required by the International Building Code (IBC), these analysis procedures are based on comparisons of data from floor/ceiling assemblies having STC and IIC ratings as determined by the test procedures set forth in ASTM E90 and ASTM E492, respectively. The models presented in this report can be used to estimate STC and IIC ratings of: a.) light-frame floor/ceiling assemblies framed with either sawn lumber, wood I-joists, or wood trusses and b) mass timber floor/ceiling assemblies constructed with either cross-laminated timber (CLT), dowel-laminated timber (DLT), or veneer-based mass timber. Descriptions of the models are provided. Validation and application of the models are also discussed.
Quantifying northern bottlenose and sperm whale acoustic behavioural responses to anthropogenic noise in Baffin Bay, Canada
Authors: Franklin Kimberly , Halliday William D. , Barclay David R. , Fortune Sarah
Published: July 2024

Marine mammals rely on their auditory system for a myriad of life functions (e.g., navigating, foraging, socializing) and consequently, are vulnerable to loud human activities (e.g., vessel traffic, fishing, military activities). These activities can impede communication, cause behavioural disturbances, and can even cause injuries. As the Arctic warms and sea ice coverage decreases, more opportunities for human activities are arising. How noise impacts the acoustic behaviour of Arctic marine mammals is unclear. In October 2022 and 2023 controlled noise exposure experiments were conducted using military sonar (source level of 176.4 dB re 1 μPa) on northern bottlenose and sperm whales in Baffin Bay while they were foraging around vessels actively fishing. Hydrophone suction-cup biologgers (DTAGs; n = 5, ∼72 cumulative hours) were used to capture vessel and sonar noises, and whale vocalizations before, during, and after the noise exposure periods. Using a click detector, focal whale clicks were identified and quantitatively compared to received noise levels. This information will then be used to determine noise thresholds for acoustical behavioural responses. These results will support risk-mitigation strategies for the Department of National Defence Canada and Fisheries and Oceans Canada, as well as address Inuit concerns about the effects of military sonar on marine mammals.
A robotic platform for mimicking the flapping flight of bats
Authors: Kelley Logan , Park Jungsoo , Leonessa Alexander , Müller Rolf
Published: July 2024

To understand how bats control their wing movements based on biosonar inputs, it is important to identify the key kinematic synergies that need to be replicated on a robotic prototype so its wingbeat patterns and aerodynamic capabilities matches its biological counterpart. Attempting to replicate the approximately 20 degrees of freedom in each bat wing is challenging since more mechanical degrees of freedom increase mass and reduce reliability. Our proposed approach, is based on recordings of the kinematics of maneuvering bats that are obtained from high-speed camera data. The first two synergistic actions to implemented in the robot were wing flapping and folding that work together to increase net lift generation. During straight flight, these synergies follow a fixed synchronized pattern allowing a single-actuator robot model to mimic key bat flight characteristics. By recording the robot prototype's flight kinematics with the same high-speed camera setup, we can compare the flight kinematics of bats and flapping-flight robots inspired by them, quantifying differences in complexity and performance. The goal is a bioinspired robotic platform enabling detailed study of bat flight biomechanics and control strategies. This will provide new biological insights and advance flapping-flight robot development by determining kinematic complexity required for bat-like performance.
Non-equilibrium activation dynamics of superheated phase-change contrast agents
Authors: Ovenden Nicholas , Bau Luca , Stride Eleanor P.
Published: July 2024

Phase-change contrast agents, such as superheated perfluorocarbon droplets, potentially offer exciting new opportunities in diagnostic and therapeutic applications of ultrasound. An important advantage of droplets over, e.g., microbubble agents is that they can be “activated” (vaporised) by a reduction in ambient pressure, initiated by an externally applied ultrasound pulse. Controlling the timing and location of droplet activation, however, is vitally important to avoid safety concerns. Current theoretical models for droplet vaporisation assume that a critical stable bubble embryo forms that is in thermal and mechanical equilibrium. Model predictions are, however, inconsistent with some experimental observations. The aim of this study is to develop a non-equilibrium model for droplet activation wherein initial bubble growth rate and vapour pressure are dependent upon the bubble nucleus size. We demonstrate how incorporating nonequilibrium effects into theoretical models of droplet vaporisation dynamics enables better agreement of the droplet expansion with experimental data and thus provide greater insight into control of the activation process.
Peak positive pressure matters in acoustic droplet vaporization
Authors: Fiorini Samuele , Prasanna Anunay , Shakya Gazendra , Supponen Outi
Published: July 2024

We demonstrate the significance of the positive pressure component of an ultrasound wave in acoustic droplet vaporization. Theory and acoustic simulations reveal that the distorted compression part of the incoming wave, which includes a broad spectrum of frequencies above the fundamental, presents a pronounced shift in phase when focusing within the droplet and crossing the focal point. The extent of this so-called Gouy phase shift is sufficient to change the sign of the compression phase of the wave, actively creating a tension region in the droplet bulk in the same location where we experimentally observe vapor nucleation. A sign reversal of the rarefaction component of the ultrasound wave is, on the other hand, not expected. The extent of distortion of the incoming ultrasound wave can influence the occurrence of droplet vaporization, even at constant peak negative pressure, which may partially explain the broad range of vaporization threshold values reported in literature. The results suggest that vaporization can be achieved exploiting ultrasound waves with high peak positive pressures and reduced peak negative pressures.
Acousto-optic sensing: A scattering interpretation
Authors: Verburg Samuel A. , Fernandez-Grande Efren
Published: July 2024

Acousto-optic sensing consists in using (laser) light as the sensing element in order to measure, visualise and study acoustic phenomena in a remote, non-invasive manner. One of the most common sensing techniques involves measuring acoustically-induced phase shifts of an optical probing beam by means of interferometry. Arguably, the main fundamental limitation of such sensing technique is that it provides projections of the acoustic field, instead of acoustic quantities at specific locations. In this study we examine the theory of spontaneous light scattering in transparent media, and use this framework to formulate a general acousto-optic sensing problem. Preliminary results based on numerical simulations indicate that light scattering could be applied to the measurement of acoustic pressure fluctuations. Some of the main challenges associated with the principle—mainly related to the weaknesses of the acousto-optic effect in air and relatively low signal-to-noise ratio—as well as the main fundamental differences from conventional interferometry techniques are discussed in this study.
Voice perception as a bridge between psychoacoustics and speech intelligibility
Authors: Gaudrain Etienne
Published: July 2024

While clinical assessments of speech intelligibility focus on the reception of phonetic to lexical cues by a listener, in natural situations, speech also contains cues that inform the listener about the identity of the talker, or their emotional state. These indexical cues contribute to the access of phonetic information, either through talker normalisation, or by promoting the segregation of competing talkers. They can also directly affect the interpretation of the lexical content, e.g., through prosody. In other words, indexical cues play a crucial role in everyday communication. Yet, they are rarely considered in clinical evaluations of hearing impairment. Through various studies involving child and adult hearing aid and cochlear implant users, it appears that some voice cues are more affected by hearing loss than others, and this could have consequences on the development and remediation strategies. These studies also highlight the central role that voice perception study could play in connecting psychoacoustics to communication sciences. As voice literally carries the linguistic information in speech, it sits at the forefront of auditory processing. The mechanisms underpinning hearing loss thus tend to directly affect the neural representations of voice properties. As voice manipulation technologies are becoming more precise and more widely available, new opportunities arise to link peripheral auditory deficits to speech processing difficulties in populations with impaired hearing.
What do voices contribute to acoustic context effects in speech perception?
Authors: Stilp Christian E.
Published: July 2024

All perception takes place in context, and speech perception is no exception. Surrounding sounds form a context that guides speech perception. This is particularly true when earlier sounds inform the perception and/or recognition of later sounds. Several lines of research have advanced models where listeners use preceding context to account for characteristics of the talker’s voice, such as vocal tract properties, articulatory maneuvers, or the speaker’s identity. Conversely, research with nonspeech sounds and/or nonhuman animals has advanced alternative models where perception is responding more to signal acoustics than to vocal characteristics. In this talk, I will review recent evidence from our research on acoustic context effects and talker normalization when hearing speech and nonspeech (music) sounds. Parallel patterns of performance across speech and music domains are conducive to, but not definitive evidence of, acoustic context being utilized according to general signal acoustics, with speech- and voice-specific contributions coming later in the processing stream.
Speech comprehension in the context of speaker changes: The importance of voice-feature continuity at the cocktail party
Authors: Kreitewolf Jens
Published: July 2024

In this talk, I will show how different groups of listeners use voice acoustics to enhance speech comprehension under adverse listening conditions, specifically when the auditory scene comprises a multitude of sounds heard at once. These “cocktail-party”-like situations pose a difficult conceptual problem: To comprehend target speech, listeners need to attend to the target voice while at the same time ignoring other irrelevant sounds. The cocktail-party problem is made considerably easier when all target sounds are spoken by the same talker. Previous work suggests that such benefits from voice continuity can be—in large part—attributed to two prominent voice features: Glottal-pulse rate (GPR) and vocal-tract length (VTL). GPR determines the fundamental frequency of a speech sound and is perceived as vocal pitch; VTL determines the spectral envelope of a speech sound and is perceived as an aspect of vocal timbre. Apart from being important voice identity cues, GPR and VTL have been shown to play a crucial role in cocktail-party listening. Here, I will present data from a series of experiments highlighting the importance of voice-feature continuity for speech comprehension at the cocktail party.
Perception of dynamic pitch and prominence in speech
Authors: Jeon Hae-Sung
Published: July 2024

The perception of dynamic – constantly changing – pitch in speech has been extensively studied in psychoacoustics and linguistics. In psychoacoustic studies, listeners are usually presented with short stimuli such as vowels or syllables, and their ability to discriminate a pair of stimuli is assessed. On the other hand, linguistic studies concern intonation over an utterance. Intonation entails not only acoustic prominence realised by pitch, duration, and loudness, but also listeners’ knowledge about the relative prominence between syllables or between words in their language. This paper discusses a series of speech perception experiments using both psychoacoustic and linguistic tasks. Participants judged either relative pitch height or prominence between two pitch peaks or valleys in an utterance. Native English speakers in different age and dialectal groups were tested. The results showed that, first, listeners’ pitch height discrimination in the utterance context seems to be more accurate than previously reported. Second, there is a robust perceptual asymmetry between pitch peaks and valleys, the valleys posing significant challenges in perception. Third, listeners’ perception of pitch height and prominence is disassociated. The findings taken together suggest an intricate interaction between the physical properties of the stimuli and listeners’ top-down knowledge in the perception of speech intonation.
Influence of ultrasonic parameters on microstructural refinement and defect elimination in ultrasound-assisted laser-based metal additive manufacturing
Authors: Mutswatiwa Lovejoy , Todd Judith A. , Reutzel Edward , Kube Christopher M.
Published: July 2024

Acoustic cavitation, streaming, and energy absorption during solidification in ultrasound-assisted direct energy deposition additive manufacturing (DED-AM) have been reported to drive microstructural refinement, defect elimination, and mechanical property improvement. However, the influence of individual ultrasonic parameters such as frequency, amplitude, intensity, and sonication duration remains unknown. This is mainly because of challenges in real-time quantification of the influence of ultrasound on the rapid solidification and microstructural development processes encountered in ultrasound-assisted AM. High temperature and opaque molten metal confined within micro-length scale melt pools further challenge the characterization of ultrasound’s influence on microstructural development. Building upon our recent in situ observation of acoustic cavitation and streaming in sonicated laser-generated melt pools, this talk will highlight our efforts to correlate vibration frequency, amplitude, and intensity with grain size and texture of Al7075 alloy fabricated using ultrasound-assisted DED-AM. DED additively manufactured Al7075 is susceptible to solidification cracking. Therefore, this presentation will also showcase the influence of ultrasonic parameters on cracking suppression and defect elimination. In addition, the effect of sonication duration on microstructure will also be elaborated. Lastly, the presentation will showcase our future work toward upscaling ultrasound-assisted AM to large parts with complex geometries.
“He speaks great English—For a guy from Moscow”: Language ideologies in NHL media
Authors: Drake Shiloh , Baese-Berk Melissa
Published: July 2024

Ideologies about languages and countries are hard to shake, even in a multinational, multilingual setting like the National Hockey League (NHL) and the journalists who report on it. Despite its historical roots in Montréal and the dominance of Canadian and European players, the lingua franca of the NHL is English. In this work, we used qualitative analyses to examine players’, journalists’, and coaches’ attitudes toward languages other than English used on the ice. Across all groups, we found that Russian speakers were most likely to be assessed negatively, from being taciturn and unwilling to be interviewed (Frederickson, 2023) to being unlikely to speak good English (Keefe, 2023). Additionally, English-speaking players were more likely to associate positive sentiments with native North American English, Swedish, and Finnish speakers, but negative sentiments about Canadian French speakers and players from eastern European countries. Players and coaches also tended to be split on whether it was acceptable for other languages to be spoken in the locker room and on the ice. This work points to a fragmented in-group view of the acceptable language to use in professional hockey.
Measurements of mid-frequency acoustic signal variability in the Western Barents Sea
Authors: Turgut Altan , Schindall Jeffrey , Jarosz Ewa , Wijesekera Ewa
Published: July 2024

Two Vertical Line Arrays (VLAs) and one source moorings were deployed to study along- and cross-shelf acoustic propagation in the Western Barents Sea during October 12–19, 2022. An ITC 2010 source was used to transmit Linear Frequency-Modulated (LFM) acoustic signals covering a frequency band of 0.7–4.2 kHz. Several oceanographic moorings were also deployed to measure time series of ocean currents and sound-speed profiles. Analysis of the acoustic data showed strong effects of tidal currents and surface roughness on mid-frequency acoustic propagation. Along- and cross-shelf acoustic propagation data showed semidiurnal travel-time fluctuations due to tidal currents. In addition, a 15 dB increase in Transmission Loss was observed during the storm events due to rough surface scattering. Finally, an assessment of the Polar Front and its effects on acoustic propagation (both travel-time and amplitude) are studied. Several data and simulated examples are provided to demonstrate the 3D effects of a Polar front and nonlinear internal waves on mid-frequency acoustic propagation. [Work supported by the ONR.]
Toward smart acoustic spaces: embedded machine learning for sound event detection and classification in the built environment
Authors: DiPassio Tre , Heilemann Michael C. , Thompson Benjamin R. , Rutowski Jenna , Bocko Mark
Published: July 2024

Edge computing integrated into the built environment will enable the development of smart acoustic spaces in which the flexural vibrations of the walls and screens that define a space may be employed to generate and monitor sound and serve as unobtrusive and convenient audio interfaces. Integration of data processing and neural decision making on compact, low- power embedded hardware-software systems will make it possible to mediate real-time, personalized acoustic interactions of a user with their environment without the need to connect to the cloud, thus providing privacy and security. In this presentation we show how embedded machine learning (ML) models combined with vibroacoustic control and monitoring of elastic panels may be employed to perform various tasks such as speech recognition, sound source localization, or the detection of acoustic signatures of specific events such as a fall or other health emergencies. The selection of vibroacoustic features, the associated signal processing requirements, and the computational resources utilized by the ML models for various acoustic tasks will be discussed. We also highlight how the distributed modal response of extended flat panels can simplify the sensing and signal processing requirements in such systems.
The effect of decafluorobutane lipid nanoemulsion concentration on oxygen scavenging via acoustic droplet vaporization
Authors: Al Rifai Nour , Stone Kateryna , Kasiviswanathan Diviyashree , Haworth Kevin J.
Published: July 2024

Acoustic droplet vaporization (ADV) is the phase transition of liquid droplets into gas microbubbles via ultrasound. Oxygen diffuses from the surrounding fluid into the microbubbles. This study determined the efficiency of oxygen scavenging using a lipid decafluorobutane (DFB) nanoemulsion. DFB nanoemulsions were prepared using high-shear pressure homogenization. Nanoemulsion size distributions and concentrations were measured (n = 10) using a Beckman Coulter Multisizer 4. Oxygen scavenging in 95% oxygenated water was measured in a flow phantom prior to introducing DFB nanoemulsion at concentrations of 0.05 × 10−4, 0.25 × 10−4, 0.5 × 10−4, 2.5 × 10−4, and 5 × 10−4 mL/mL and with ADV nucleated by an EkoSonic catheter driven with 47 W electrical power. The DFB nanoemulsion had a modal diameter of 920 ± 60 nm, polydispersity index (PDI) of 0.11 ± 0.03, and concentration of 3.11 × 10–2 ± 0.01 × 10–2 mL/mL. No statistical significant differences was detected in droplet size distribution metrics for at least 5 h at room temperature and 23 days at 4C. The baseline oxygen partial pressure (pO2) of the water was 553 ± 8 mmHg for all experiments. Peri-ADV pO2 dropped to 505 ± 16, 398 ± 44, 348 ± 11, 231 ± 27, 241 ± 7 mmHg for increasing concentration. A significant difference in pO2 was seen between thelowest and highest concentration (p = 0.0097). The computed ADV transition efficiency was highest at 0.25 × 10−4 mL/mL.
Acoustic cluster therapy: An overview of research in cancer treatment
Authors: Bamber Jeffrey C. , Bush Nigel , Banerji Udai , Tunariu Nina , O'Leary Mark , Ragulan Chanthirika , Sontum Per , de Lange Davies Catharina , Mühlenpfordt Melina , Wennerberg Erik , Sadanandam Anguraj , Melcher Alan , Snapir Amir , Healey Andrew , Kvåle Svein
Published: July 2024

This presentation provides an overview of research on acoustic cluster therapy (ACT) in cancer treatment. ACT is a promising approach to enhancing the delivery of drugs to cancer cells that involves the use of intravenously injected clusters of microbubbles and microdroplets, which are activated by diagnostic ultrasound at the tumor site. Upon activation, the clusters expand to form bubbles of 20–40 μm diameter. When modulated by low-pressure (MI ∼ 0.2) low-frequency (∼500 kHz) ultrasound while they sit in the tumor capillaries, these bubbles generate biomechanical effects that improve drug extravasation and interstitial permeation. They dissolve after 5–10 min. The technique has been used to temporarily open the blood brain barrier, improve the effectiveness of various chemotherapeutics in a range of tumor models, and provide ACT-imaging biomarkers that predict therapeutic outcome. It has exhibited no adverse effects to-date in a phase I/II clinical trial and improved clinical response of colorectal cancer liver metastases to chemotherapy. Ongoing research is investigating the potential synergistic effects of ACT with immunotherapy.
Rayleigh-Lamb wave propagation in a prestressed transversely isotropic viscoelastic waveguide: Inverse modeling challenges
Authors: Vorobyeva Alexandra , Wang Qifeng , Klatt Dieter , Shull Kenneth , Perreault Eric J. , Royston Thomas
Published: July 2024

The functional role and structure of skeletal muscle results in anisotropy in both material properties and imposed stresses, as well as waveguide effects. Dynamic elastography reconstruction methods for estimating muscle tissue viscoelastic properties that are rooted in assumptions of isotropy and bulk wave motion may produce inaccurate estimates. The superposition of axially-aligned orthotropy (transverse isotropy) in material properties and axially-aligned prestress conditions due to passive stretch or muscle activation makes it difficult to independently discern how much of the apparent anisotropy is due to the muscle material or the imposed stress field. Furthermore, this stress field may result in large strain conditions that require use of higher order terms in the stress-strain relationship. The significance of this confounding condition and strategies for decoupling material and stress-based anisotropy are investigated with a series of numerical finite element and experimental elastography studies using scanning laser Doppler vibrometry and magnetic resonance elastography. Shear and Rayleigh-Lamb wave motion is studied in a polymeric muscle phantom that is in the shape of a rectangular rod and has either isotropic or transversely isotropic material properties under zero stress conditions. [Funding support: NIH AR071162]
Using music to motivate learning mathematics in acoustics courses
Authors: Ramsey Gordon P.
Published: July 2024

Mathematics often intimidates students, especially if they feel unprepared for the math level in the course. However, when they see how math and music are intimately related, their attitude often changes. Many fundamental aspects of music are described by math. These include note frequencies, chords and scales, consonance and dissonance, and instrument tuning. The reactions to music of consonance and dissonance are related to the relative ratios of the notes in a chord or note sequence in a piece. The connection between music and math forms the basis for designing instruments that play the music. Instruments must be designed to replicate the note frequencies, while their geometry allows them to be being playable by humans. Mathematics is at the heart of instrument design. I will suggest ways to present these concepts to students for their greater appreciation of how acoustics and math are related.
AI-based headphones for augmenting human hearing
Authors: Veluri Bandhav , Itani Malek , Chen Tuochao , Gollakota Shyamnath
Published: July 2024

Consider being able to listen to the birds chirping in a park without hearing the chatter from other hikers, or being able to block out traffic noise on a busy street while still being able to hear emergency sirens and car honks. We introduce semantic hearing, a novel capability for hearable devices that enables them to, in real-time, focus on, or ignore, specific sounds from real-world environments, while also preserving the spatial cues. Results show that our system can operate with 20 sound classes and that our transformer-based network has a runtime of 6.56 ms on a connected smartphone. In-the-wild evaluation with participants in previously unseen indoor and outdoor scenarios shows that our proof-of-concept system can extract the target sounds and generalize to preserve the spatial cues in its binaural output.
Buried object localization by spectral analysis of surface wave reflections
Authors: Baumann David , Hagelthorn Emily , Heiny Andrew , Hildebrand Robert , Kelly Morgan , Kucuk Haluk , Mangone Dustin , Nobani Omar , Zarepoor Masoud
Published: July 2024

A proposed method of buried object localization, based upon spectral analysis of surface wave reflections, is investigated numerically. This arises from a hypothesis to the effect that reflectivity would be maximized at some intermediate wavelength, shorter ones associated with disturbances too shallow to substantially excite the object as a secondary (reflecting) source, and longer ones with disturbances involving such volumes of earth in motion that the object become insignificant as a reflector. Discernment of that intermediate wavelength of maximum reflectivity might, thereby, provide an index of the object’s depth. Horizontal distance from echo return time, and azimuth from phase array techniques, could complete a localization methodology. Presented, accordingly, are 2D FEA simulations, in which narrow-banded surface wave trains are excited by a point source on the surface of an elastic medium, a void provided at some horizontal distance and depth, the strength of reflected surface motions thereafter examined in relation to frequency. These bear out the hypothesis, finding maximal reflectivity for a surface wavelength about two-thirds of the object depth. Proposed is that this could serve as the basis for a horizontal stand-off detection method, especially for applications like landmines, for which it may be undesirable to scan from above.
Performance on a spatially selective auditory attention listening task for sources in the horizontal or coronal planes
Authors: Otto Grace E. , Macpherson Ewan A.
Published: July 2024

Listeners can use spatially selective auditory attention (SSAA) to focus on one talker in a complex acoustic scene. SSAA has been primarily investigated with targets and distractors arrayed in the frontal horizontal plane. In this study we compared normally hearing human listeners' performance on static and dynamic SSAA tasks in a frontal target/distractor configuration to performance with sources arrayed in either the rear horizontal plane, the overhead coronal plane, or the “underhead” coronal plane, all of which provide similar binaural difference cues with which to differentiate target and distractor locations. To achieve the coronal plane configurations, the listener's head was tipped forward to align the normally vertical axis with the horizontal plane. In the SSAA task, listeners attempted to report a 4-digit sequence of spoken digits from the target location while ignoring two simultaneous equal-intensity sequences spoken by the same talker presented from flanking loudspeakers separated by ±22.5° from the target. Listeners either held their head still (static conditions) with the front (horizontal configurations) or top (coronal configurations) of the head oriented toward 0 azimuth, or were oscillated passively at ∼0.14 Hz with an amplitude of ±45 degrees about the vertical axis (dynamic conditions).
The contributions of acoustic and non-acoustic factors to spatial release from masking
Authors: Barkhouse Morgan , O'Neill Sadie , Patro Chhayakanta , Srinivasan Nirmal Kumar
Published: July 2024

The ability to identify speech at worse signal-to-noise ratios when the maskers are spatially separated compared to when they are colocated is called spatial release from masking (SRM) and is thought to be a combination of monaural and binaural advantages arising from spatially separating the target from the maskers. Also, a host of other cognitive skills including attention, working memory, and executive function that support listeners’ ability to segregate, track and attend to a “target” signal while tuning out other unwanted signals contributes to understanding speech better in complex environments. Previous research with young normal hearing listeners from our lab indicated that SRM was predicted by an individual’s ability to use binaural cues (ITD thresholds), switch attention between two streams of information (trail making test) and ability to suppress irrelevant information (flanker task). Here, we present data from older listeners with varying hearing abilities on acoustic (envITD sensitivity) and non-acoustic tasks measuring attention (auditory and visual single and dual task), processing (trail making task), executive control (flanker task) and speech in noise tests (spatial release from masking using coordinate Response Measure sentences). The relationship between these acoustic and non-acoustic factors to speech understanding in complex listening environments will be discussed.
Bidirectional C-to-V coarticulation across syllable and word boundaries
Authors: Li Scarlet Wan Yee , Ahn Suzy
Published: July 2024

Extensive work has explored the anticipatory or carryover coarticulatory effects of consonants on F2 of adjacent vowels using locus equation. However, studies examining bidirectional effects remain scarce. This study examines how voicing and place of articulation (PoA) of consonants affect bidirectional C-to-V coarticulation across syllable and word boundaries. Recordings of / C;1V;1.C;2V;2/, /C;1V;1#C;2V;2/ and /C;1V;1C;2#V;2t/ sequences from native speakers of Canadian English were analyzed. F0, F1, and F2 were measured at the onset and offset of the target vowels (/i ɑ/) to compare the coarticulatory effects caused by the adjacent consonants with different voicing and PoA (/p b t d g k/). Preliminary results (N = 6) indicate that coarticulatory effects vary based on voicing and PoA of consonants. Voiceless consonants exhibited a greater effect on f0 bidirectionally, but smaller effects on F1 and F2. Regarding PoA, only the effect of F2 in anticipatory contexts was dependent on different PoA. The findings also suggest that bidirectional coarticulatory effects are found across both syllable and word boundaries. Within and across these boundaries, larger anticipatory effects were found on f0, while the carryover effect on F1 was more robust. Concerning F2, differences between coarticulatory effects were only evident in voiceless and velar contexts.
Phonetics characteristics of seoul korean tense stops
Authors: Kwon Harim , Ahn Suzy
Published: July 2024

This study investigates Seoul Korean tense stops, asking whether underlying intervocalic tense stops in /at*a ap*a ak*a/ share phonetic characteristics with those derived from a sequence of two lax stops by applying the post-obstruent tensing rule /at.ta ap.pa ak.ka/ → [at*a ap*a ak*a]. To examine whether the tense stops show articulatory fortition compared to lax stops, and if so, whether the underlying and derived tense stops differ from each other, tongue configuration and closure duration of tense stops in [at*a ap*a ak*a] that are underlyingly either /at*a ap*a ak*a/ or /at.ta ap.pa ak.ka/ are compared with those of lax stops in [ata apa aka]. Ultrasound tongue imaging data from six native speakers of Seoul Korean reveal indistinguishable tongue configurations among underlying tense stops, tense stops derived from underlying lax sequences, and lax stops. Both derived and underlying tense stops have longer closure duration than lax stops, but the two surface tense stops did not significantly differ in their closure duration. Taking the articulatory and acoustic evidence together, underlying and derived tense stops in Seoul Korean are phonetically indistinguishable from each other although both have longer closure durations than singleton lax stops. The findings further suggest that Seoul Korean may not use tongue configuration as an articulatory strategy for fortition for either underlying or derived tense stops.
Regional differences in the production of tones in standard mandarin
Authors: Fei Sishi
Published: July 2024

This study investigates the intricate patterns of tonal variations in monosyllabic words across distinct regional accents of Standard Mandarin, with a focus on Shanghai, Guangzhou, and Beijing. Due to the differing tonal systems of the local Chinese dialects in the three cities, speakers from these areas may exhibit distinct patterns in their production of tones in Standard Mandarin, influenced by their native Chinese dialects. Therefore, to capture the nuances of tonal differences, the study extracts the time-normalized f0 values of four tones (i.e., level, rising, dipping, and falling tones) from monosyllabic words in a Mandarin Chinese speech corpus. The overall f0 contours of the four tones within and across the three regional accents are modeled using growth curve analysis. We expect to find that regional accents of Standard Mandarin exhibit significant tonal variations such that the tone shapes of speakers from Shanghai and Guangzhou may significantly deviate from those of Beijing speakers. Specifically, there are variations in contour shape and temporal dynamics, particularly in the quadratic term for dipping tones and the slopes of rising and falling tones. These findings can provide valuable insights into the intricate characteristics of regional tonal variations in Standard Mandarin.
The [s -- > ʃ] sound change in /str-/ contexts: how temporal changes in the acoustic spectrum affect fricative percept
Authors: Shadle Christine H. , Koenig Laura L. , Chen Wei-rong
Published: July 2024

Studies have documented a sound change in some English dialects whereby /s/ in the context /strV/ surfaces as [ʃtrV]. This can be interpreted as /s/ rounding for the rhotic being re-analyzed as [ʃ]. We recently measured F;M, the frequency of the main peak in mid-fricative spectra, in seven adults producing words with /s/ and /ʃ/ across phonetic contexts and compared the acoustics to perceptual rankings on an [ʃ] to [s] scale. One speaker exhibited a perceived sound change; two, partial sound changes. It was shown that F;M was correlated with the perceptual rankings for /strV/ words. However, in all speakers, lowered F;M for /s/ in labial contexts did not affect percepts. The time course of lip rounding and tongue-tip retraction in /strV/ could help differentiate coarticulation versus a phonemic change. Interestingly, however, X-Ray Microbeam data [Iskarous, K. et al. (2011) Articulatory-acoustic kinematics of /s/, J. Acoust. Soc. Am. 129, 944-954] showed that / s/ constriction location was constant over time except in /str-/ context. This study will assess the amount and timing of F;M lowering, its perceptual consequences and likely articulatory causes, to gain more insight into the [strV] -- > [ʃtrV] sound change.
Understanding model fidelity for training synthetic aperture sonar image classifiers
Authors: Blanford Thomas E. , Williams David , Park J. Daniel , Reinhardt Brian , Johnson Shawn , Brown Daniel C.
Published: July 2024

Convolutional neural networks (CNNs) are increasingly employed for classification tasks in automated target recognition (ATR) algorithms for synthetic aperture sonar (SAS) images. Training ATR algorithms, however, requires many unique observations of the targets of interest. Data available for training is often limited, and acquiring additional training data through experimentation is prohibitively expensive. Increasingly, training with simulated data is being considered as an alternative, but the fidelity required of the models that generate this data is not yet known. SAS imagery typically contains significant complexity from countless physical mechanisms. Simulating complex scenes requires multiple models to account for these different effects, but some effects may not require accurate modeling for the purposes of training an ATR algorithm. This presentation will describe a study to investigate the fidelity of models required so that simulated data may be used interchangeably with experimental data for training CNNs. Using in-air experimentation, a high-fidelity data set was developed with multiple degrees of complexity. A high-frequency sonar signal model was then used to generate complementary simulated data. This approach allows for specific physical features in the data to be individually isolated, enabling detailed exploration of the relationships between model fidelity and CNN architecture.
Temporal evolution of sound pulse in shallow water under conditions of horizontal refraction. Vertical modes and space-time horizontal rays
Authors: Katsnelson Boris , Kaplun Alexander
Published: July 2024

As is known, to describe horizontal refraction in a shallow water waveguide, the “vertical modes and horizontal rays” approach (Burridge & Weinberg, 1974) is used, within which the two-dimensional eikonal equation for the modal amplitude includes the refractive index determined by the eigenvalues depending on the horizontal coordinates (x,y) and frequency (f). In other words, we have an effective two-dimensional inhomogeneous dispersive medium, to describe the propagation of signals in which, the authors propose to use the so-called space-time rays (Rytov, 1940, Connor & Felsen, 1974, Hillion, 1993) applied for the horizontal plane (STHR). The set of STHRs in a given situation is constructed for each mode. Within the framework of this approach, it is possible to obtain the evolution of the pulses of each mode from the solution of the nonstationary eikonal equation in the horizontal plane or from the corresponding Hamilton-Jacobi equations, obtained using non-local integral wave equation. Examples of constructing STHR in some typical situations (in particular in a wedge) are considered, some specific effects during signal propagation are considered, in particular, the so-called the pulse front tilt, previously discovered in laser optics (Bor & Rasz, 1985). Work was supported by ISF, grant 946/20.
Using different methods to measure ultrasonic attenuation in cortical bone: A comparison
Authors: McCandless Brett A. , Raum Kay , Muller Marie
Published: July 2024

The assessment of bone mineral density (BMD) and bone microstructure is important in screening for various bone diseases. Dual x-ray absorptiometry is the most commonly used technique for evaluating BMD; however, alternatives are necessary due to the use of ionizing radiation and low resolution, the latter of which prevents obtaining information on bone microstructure. Quantitative ultrasound presents a potentially attractive alternative. The microstructure of porous media, such as cortical bone, influences the attenuation of ultrasound; as such, ultrasound attenuation can be used to obtain information about the microstructure of cortical bone. Different models and measurement methods may be used to estimate ultrasonic attenuation in a cortical bone. In this study, three different methods of measuring ultrasonic attenuation were used. Finite-difference time-domain simulations were conducted in maps mimicking cortical bone. Pore densities and pore size distributions in the bone matrix, as well as absorptive properties of the bone and porous matrices, were specified for all simulations. Attenuation was measured within the pulse bandwidth as a function of frequency using the independent scattering approximation (ISA), a cortical backscatter method (CortBS), and the reflections from the two surfaces of the cortical bone map. Excellent agreement was found between these three methods.
An MR-compatible fiber-optic probe for measuring focused ultrasound-induced temperature rises without viscous heating artifacts
Authors: Johnson Sara L. , Odeen Henrik , Payne Allison , Vine Harry
Published: July 2024

Focused ultrasound (FUS) beam interactions with thermocouples and fiber optic (FO) probes cause a “viscous heating artifact” (VHA), which prevent accurate temperature measurements during acoustic sonication. This work demonstrates a novel fiber-optic temperature probe which is insensitive to VHA, validated in an MR-guided FUS treatment setting. The FO probe (OSENSA Innovations; PRB-140, 0.14 mm diameter) was inserted with an 18G catheter into a tissue-mimicking gelatin phantom. The FO probe tip was located with high-resolution MR images (0.25 × 0.25 × 0.5 mm3) for targeting with FUS. Continuous-wave FUS sonications (50 W, 20 s) were delivered at a distance of ∼1.5 mm from the FO probe tip using a 256 phased-array transducer (Imasonic, France; 1 MHz, 2.1 × 2.3 × 9.8 FWHM spot size) and FUS-induced heating was measured with 3D MR temperature imaging (MRTI; 0.5 × 0.5 × 1 mm3 resolution, 3.9 s acquisition). The VHA effect was not observed in the PRB-140 FO probe measurement data. The FO probe heating and cooling curves closely matched those measured by MRTI, with a root mean-squared error (RMSE) of 0.61 °C. In contrast, the RMSE of VHA-sensitive FO probe was 6.00 °C for a similar acoustic power output. This ultrasound artifact-immune FO temperature probe is highly advantageous for MR temperature sequence development and precise temperature monitoring in FUS treatment applications.
Optimizing intracardiac flow assessment with high frequency ultrasound in a mouse model
Authors: Wahyulaksana Geraldi , Phoon Colin K. L. , Fishman Glenn I. , Ketterling Jeffrey A.
Published: July 2024

Cardiomyopathy, a disorder affecting the heart muscle, is associated with severe symptoms, such as heart failure, arrhythmia, or cardiac arrest. Echocardiography is the primary clinical tool for myocardial assessment, which provides diagnostic and prognostic insights. However, current clinical parameters, such as myocardial strain, often detect the condition only after symptoms become pronounced, showing the need for early-stage assessment. Based on preliminary studies, intracardiac flow patterns have the potential to detect abnormal myocardial changes earlier than the current clinical parameters. Mouse models are commonly imaged with ultrasound in the cardiovascular disease research but their use for flow pattern evaluation has been hindered by spatial and temporal resolution limitations. Here, we address this limitation by conducting data acquisition using a Verasonics scanner with a range of high-frequency probes (16 to 42 MHz), transmit cycles, and transmit angles. A singular value decomposition (SVD) filter and frequency de-aliasing were also investigated to optimize flow quantification. Our findings show that a higher transmission frequency, while providing superior spatial resolution, may not yield the best flow quantification due to increased Doppler aliasing. Furthermore, SVD filtering and Doppler de-aliasing should be used with caution because improper implementation can adversely impact the quantification results.
Towards real-time decompression sickness mitigation using wearable capacitive micromachined ultrasonic transducer arrays
Authors: Currens Joshua B. , Annayev Muhammetgeldi , Kemal Remzi Erkan , Eltz Katherine M. , Azarang Arian , Natoli Michael , Lance Rachel M. , Moon Richard E. , Dayton Paul A. , Yamaner Feysel Yalcin , Oralkan Omer , Papadopoulou Virginie
Published: July 2024

Decompression sickness (DCS) due to inert gas supersaturation remains one of the major risks for scuba divers and can occur despite adherence to prevention schedules for staged decompression. Post-dive echocardiography for venous gas emboli (VGE) detection has low sensitivity for DCS outcome and is unable to provide real-time physiological monitoring underwater. Alternatively, we present progress towards collecting ultrasound data while at pressure and an exploration into a quantitative assessment for decompression stress. Ultrasound data of an imaging phantom were collected in a hyperbaric chamber up to 9 ATA using a Verasonics V1 system and custom capacitive micromachined ultrasonic transducer (CMUT). The DC voltage requirement for CMUT operation decreased as ambient pressure increased. Separately, a mouse model was used to simulate an extreme pressure profile and echocardiograms were collected every 20 min over 2-h post-decompression. Towards enhancement of DCS assessment, a quantitative analysis of the murine echocardiograms was implemented. Preliminary results show an increase in signal intensity within the venous blood from pre- to post-dive, indicating potential gas presence despite VGE absence. Our findings demonstrate the ability to obtain ultrasound data at pressure and a potential continuous assessment method, which may provide a practical direction for real- time decompression stress quantification.