bluuebunny/crossref_metadata_2025 huggingface dataset:
Measurements of classroom acoustic conditions in which young neurodiverse persons learn in São Paulo and Nebraska
Authors: Caldas Fernanda , Teodoro De Cillo Fernando , Underwood Samuel H. , Kumar Sanjay , Valler Celeri Eloisa , Masiero Bruno , Wang Lily M.
Published: April 2023

Autism is a set of complex neurobehavioral conditions that involve, among other characteristics, hypo/hypersensitive responses to any sensory input, usually referred to as sensory processing disorder. The most common sensory difference associated with autistic individuals is an over or under response to visuals, touch, smells, tastes, balance, and sounds when compared to neurotypical individuals. Among these, auditory sensitivity has a significant influence. Research studies to date have revealed that autistic individuals are highly susceptible to surrounding sounds, and show that certain noises, such as loud sounds, classroom bells, sirens, the radio or the TV, and traffic noise, may induce uncomfortable and distracting behavior. In this study, we investigated the acoustic environment of classrooms/facilities designed for a more inclusive education. A number of room acoustic descriptors, such as reverberation time (RT), speech clarity (C50), speech transmission index (STI), sound levels, and auditory strength (S/N ratio) were measured in this regard. The experimental measurements were performed in several rooms and facilities focusing on autistic individuals in Campinas, São Paulo, in Brazil and in Omaha, Nebraska, in the United States.
The quest for the biosonar image of the world
Authors: Müller Rolf
Published: April 2023

The large differences in the wavelength of visible light and the ultrasonic pulses of bat biosonar raise the question whether the sensory world of bats is the same as that of humans and other visual animals, completely different, or something in-between. Pioneering research on this question has focused on the range dimension of biosonar perception exploiting the straightforward relationship between echo delay and target range. Furthermore, since bat ears are typically no more than a single order of magnitude longer than the respective ultrasonic wavelengths, the beam patterns of the animals are fairly wide, which can be expected to result in a much better resolution for range than along the cross-range dimension. Bats that use their biosonar to navigate in densely vegetated environments receive echoes containing contributions from many unresolved scatterers, i.e., “clutter echoes.” Extracting useful information from clutter has been studied using real-world data collected with biomimetic sonar systems and analyzed with deep-learning methods. The results demonstrate that useful information can be extracted from clutter echoes without the formation of an image, i.e., without a systematic spatial representation of resolved objects. Hence, many interesting aspects of how bats experience their sensory worlds may still be left to be discovered.
Neural responses of the auditory midbrain to naturalistic echolocation sequences in Hipposideros armiger
Authors: Cui Zhongdan , Luo Jinhong
Published: April 2023

The functional properties of the auditory midbrain, inferior colliculus (IC), plays a critical role in James Simmons’s SCAT model of target ranging by echolocation. This SCAT model is based solely on the big brown bat producing frequency-modulated (FM) sonar calls. By contrast, there has been very limited knowledge on how the auditory midbrain may encode target ranging information in bats that produce constant-frequency (CF) sonar calls. Here, we conducted single-unit recordings from the auditory midbrain of passively listening Hipposideros armiger using naturalistic echolocation sequences. We created echolocation sequences from recordings taken from individual bats swung on a moving pendulum that evokes Doppler shift compensation (DSC) of their sonar vocalizations. Our preliminary data revealed a population of IC neurons selectively responded to DSC information in the sequences. To our surprise, we did not find neurons that encode echo delays. Considering published data on FM bats, these results suggest that the functional role of auditory midbrain for echolocation may be distinct between FM bats and CF-FM bats.
Photoacoustic imaging for assessment of abnormal placental function during pregnancy
Authors: Bayer Carolyn
Published: April 2023

Insufficient placental function is a comorbidity of many pregnancy pathologies, including preeclampsia, and may be a driver of epigenetic changes affecting the future health of mother and child. Existing ultrasound imaging modalities assess placental anatomy, but provide insufficient information about function, limiting clinical care. Our research develops photoacoustic imaging of placental function to characterize progression and treatment of placental-related diseases. In photoacoustic imaging, short laser pulses generate acoustic signals from light-absorbing chromophores within the tissue. Since the optical absorption of many tissue chromophores is wavelength dependent, by varying the wavelength of the laser, estimates of the tissue composition can be obtained through analytical fitting of the acquired photoacoustic signal to the known optical absorption of the tissue chromophores, termed spectral photoacoustic imaging (sPA). sPA imaging was applied to demonstrate that ischemia of the placenta is a defining condition of preeclampsia in a preclinical animal model of the disease, and that therapeutics demonstrate a mechanism-specific reduction in the extent of ischemia in the preeclamptic placenta. Currently, tissue optical attenuation limits the imaging depth of photoacoustic imaging, but strategies are being developed to improve imaging depth and potentially enable clinical translation.
Binary acoustic metasurfaces for transcranial focused ultrasound
Authors: Hu Zhongtao , Yang Yaoheng , Xu Lu , Hao Yao , Chen Hong
Published: April 2023

Transcranial focused ultrasound is a promising technique for noninvasive and spatially targeted diagnosis and treatment of brain diseases. Acoustic lenses were designed to correct the skull-induced beam aberration, but these designs could only generate static focused ultrasound beams inside the brain. Here, we designed and 3D printed binary acoustic metasurfaces (BAMs) for skull aberration correction and dynamic ultrasound beam focusing. BAMs were designed by binarizing the phase distribution at the surface of the metasurfaces. The phase distribution was calculated based on time reversal to correct the skull-induced phase aberration. The binarization enabled the ultrasound beam to be dynamically steered along wave propagation direction by adjusting the operation frequency of the incident ultrasound wave. The designed BAMs were manufactured by 3D printing with two coding bits, a polylactic acid unit for bit “1” and a water unit for bit “0.” BAMs for single- and multi-point focusing through the human skull were designed, 3D printed, and validated numerically and experimentally. In summary, the proposed BAMs with subwavelength scale in thickness are simple to design, easy to fabric, and capable of correcting skull aberration and achieving dynamic beam steering.
Airy beam-enabled binary acoustic metasurfaces (AB-BAM)
Authors: Hu Zhongtao , Yang Yaoheng , Xu Lu , Jing Yun , Chen Hong
Published: April 2023

Airy beams have offered great opportunities for ultrasound beam manipulation. However, one critical barrier that limits the broad applications of Airy beams in ultrasound is the lack of simply built device to generate Airy beams in water. This work presents a family of Airy beam-enabled binary acoustic metasurfaces (AB-BAMs) for underwater ultrasound beam manipulation. AB-BAMs are designed and fabricated by 3D printing with two coding bits: a polylactic acid unit acting as a bit “1” and a water unit acting as a bit “0.” The distribution of the binary units is determined by the pattern of Airy beam. We demonstrate the capability of AB-BAMs in flexibly tuning the focal region size and beam focusing in 3D space. The focal depth of AB-BAMs can be continuous and electronical tuned by adjusting the operating frequency of the planar transducer without replacing the AB-BAMs. The superimposing method is leveraged to enable the generation of complex acoustic fields. Furthermore, the proposed 3D-printed AB-BAMs are simple to design, easy to fabricate, and low-cost to produce with the capabilities to achieve tunable focal size, flexible 3D beam focusing, arbitrary multipoint focusing, and continuous steerability, which creates unprecedented potential for ultrasound beam manipulation.
Shaveless focused-ultrasound-induced blood-brain barrier opening in mice
Authors: Xu Lu , Gong Yan , Chien Chih-Yen , Chen Hong
Published: April 2023

To demonstrate that focused ultrasound-induced blood-brain barrier opening (FUS-BBBO) in mice can be achieved without shaving hairs. We performed FUS-BBBO in mice by using oil as the coupling medium without shaving hairs. The hydrophobic nature of oil leads to a higher affinity to hair than water-based ultrasound gel. FUS-BBBO outcome was compared under three conditions: “oil + hairs,” “gel + hairs,” and “gel + no hairs.” T2-weighted, T1-weighted MRI, and fluorescence imaging of the ex vivo brain slices were performed to measure the quality of coupling and outcome of FUS-BBBO. Results showed that “oil + hairs” consistently achieved high-quality acoustic coupling without trapping air bubbles (Figures A & B). FUS-BBBO outcome was not significantly different between the “oil + hairs” group and the “gel + no hairs” group based on T1-weighted MRI (Figures C & D) and ex vivo fluorescence imaging (Figure E). The FUS-BBBO efficiencies for both the “oil + hairs” and “gel + no hairs” groups were significantly higher than the “gel + hairs” group. This study demonstrated that FUS-BBBO in mice could be achieved without shaving hairs. Oil provides a simple solution for achieving effective acoustic coupling for transcranial FUS procedures.
Tornado infrasound: Observations and potential mechanisms
Authors: Elbing Brian R. , Wilson Trevor C. , Petrin Chris , KC Real J. , Swaim Taylor , Lindsey Bryce B.
Published: April 2023

Tornado warnings have not improved over the past 20 years, which is especially true in hilly terrain where radar cannot see near the ground due to the curvature of the earth. While Tornado Alley is best known for tornadoes, most tornado related deaths occur in the southeastern US where hilly terrain is more prevalent. Tornadoes emit sounds at frequencies below what humans can hear (infrasound), and there is strong evidence that these sounds carry information about the forming of the tornado as well as its size. In addition, these very low frequencies can travel well beyond the line-of-sight. Currently, this information is not used to guide warnings because we do not understand what makes it. Our team has been working on identifying the fluid mechanism for the past few years and there are four commonly proposed mechanisms that are consistent with observations; radial oscillation, latent heat effect, pressure relaxation, and shear instability. In this presentation each mechanism will be discussed relative to available observations. In addition, an overview of current field and laboratory testing motivated by the success and limitations of each proposed mechanism will be discussed.
Parylene as an electret for condenser microphones
Authors: Grigg Benjamin J.
Published: April 2023

Electrets in condenser microphones are typically made from varieties of Teflon. This work evaluates different formulations and thicknesses of vapor deposited Parylene electrets as potential alternatives to Teflon. Parylene-coated condenser backplates used in this study were obtained from two different suppliers, as a third variable in addition to formulation and thickness. Long-term charge stability of the electrets was tested with a thermally stimulated discharge (TSD) method. Charge stability was also evaluated by building the charged backplates into condenser microphones and running them through environmental accelerated-life testing. Standard PTFE and FEP Teflon backplates were used as controls in these tests. The experiments showed clear differences in the long-term charge stability of the Parylene electrets due to thickness, formulation, and supplier. Several combinations of thickness, formulation, and supplier were found to perform comparably to traditional Teflon electrets and appear suitable for use in high-end condenser microphones.
Speakers—As a sensor and actuator for ear condition monitoring
Authors: Kim Noori , Alexander Joshua M.
Published: April 2023

Acoustic devices such as microphones and speakers are critical tools in modern hearing care research. When utilizing acoustic data for such devices, most approaches drive sound signals from speakers and obtain corresponding electrical signals from microphones. However, significant opportunities and valuable information are missed if researchers conclude that a speaker is just a sounding device. It should be noted that traditional acoustic pressure measurement with microphones requires complex signal processing, such as noise filtering, to overcome crosstalk and noises from various sources. This approach engineers a speaker as an actuator and a sensor simultaneously. Electrical input impedance from an earphone’s speaker will be monitored and measured to detect acoustic load statuses such as ear conditions such as blocked or opened. Speakers are two-port electroacoustic transducers, based on our previous work, and they can be used as more powerful tools to provide important physiological information related to hearing sensitivities and acoustic load changes. The electrical input impedance data contain static information of acoustic loads. It is feasible that this additional information captured from the speaker may supplement the acoustic pressure measurement to enhance the microphone’s data when an acoustic probe is used for clinical use.
Thermoacoustic signals generated from pulsed microwave ablation in liver tissue
Authors: Evans Audrey L. , Hagness Susan C. , Ma Chu
Published: April 2023

Microwave-induced thermoacoustic signals are generated when pulsed microwave energy is absorbed by tissue. Thermoacoustic signals contain information about the electromagnetic, thermal, and acoustic material properties of the tissue. Thus, we propose using microwave-induced thermoacoustic signals to monitor microwave ablation, a thermal therapy used to heat and kill malignant tissue, in real-time. Conventional microwave-induced thermoacoustic signals are excited using an external waveguide. Our approach excites thermoacoustic signals via pulsed microwave energy delivered by the already present interstitial microwave ablation antenna. In this talk, we will present the experimental investigation of the evolution of microwave-induced thermoacoustic signals generated during microwave ablation in bovine liver tissue. Pulsed microwave energy was delivered via a narrow-diameter coaxial ablation antenna to simultaneously ablate tissue and excite thermoacoustic signals. Trials were conducted in room-temperature fresh liver tissue as well as room-temperature boiled liver tissue to investigate the influence of ablative temperature rise and tissue coagulation on thermoacoustic signals. Our experimental results show thermoacoustic signal characteristics change throughout the course of microwave ablation that could potentially be used for monitoring the microwave ablation process.
Strongly focused nonlinear surface acoustic wave beams in isotropic solids
Authors: McCollom Brittany A. , Cormack John M. , Baldini Edoardo , Hamilton Mark F.
Published: April 2023

A promising direction in the tailored control of quantum materials is the modification of their structure-function relationship via engineered laser-driven shock waves. In order to inform how the laser excitation should be tailored to optimize the effect of the shock waves, a model is desired for strongly focused nonlinear surface waves in crystals. A model was developed previously in the paraxial approximation for weakly diffracting nonlinear surface wave beams in isotropic solids [Shull et al., JASA 97, 2126 (1995)]. Harmonic generation and shock formation were investigated numerically in that work for sources with uniform amplitude distributions, with analytical solutions for the fundamental and second harmonic obtained for weakly focused Gaussian beams. Here, numerical results are reported for shock formation in focused nonlinear surface waves obtained using a model unrestricted by the paraxial approximation in order to accommodate strong focusing in isotropic solids. Removal of the restriction to isotropic solids is work in progress based on representation of the wave field in terms of its angular spectrum and a model for planar nonlinear surface waves in crystals [Hamilton et al., JASA 105, 639 (1999)]. [Work supported by the IR&D Program at Applied Research Laboratories.]
A phonetic contrast function to improve sound processing in hearing aids
Authors: Kamath Prasad Madhava , Sokolova Alice , Hunt Martin , Rao Bhaskar D. , Garudadri Harinath
Published: April 2023

An objective of a hearing aid (HA) is to improve speech communication for the hearing-impaired listeners. The current best practices for dispensing HAs involve pure tone audiometry (PTA), a functional test that characterizes ability to detect pure tones, but not perception of complex time-frequency patterns in natural speech. We present a phonetic-contrast function (PCF) that takes a test-reference pair from the Minimal Contrast Set (MCS) and generates a time-frequency-energy matrix of contrast regions. The test word is first time-aligned to the reference word using modified dynamic time warping. The frequency axis is composed of 11 bands defined by an audiometric filterbank presented in a companion work. The energy is in a pseudo dB scale in the ±120 dBSPL range. We will demonstrate the operation of PCF for English MCS spoken by a male and a female speaker. In a companion work, we developed a functional test for listening competence based on MCS that include substitutions, deletions, and insertions of acoustic-phonetic features in the stimuli, as in [lock, log, locks]. Future work includes PCF-based investigations with hearing impaired listeners to improve intelligibility of fricatives, stops, etc. by refining the HA parameters in the 11 audiometric frequencies used in sound processing.
Effect of cone angles on the acoustical properties of spinodoid structures
Authors: Wojciechowski Brittany , Sharma Bhisham
Published: April 2023

Our recent investigations [1] show that the sound absorption behavior of spinodoid structures is highly dependent on their underlying spinodal-like cellular architecture. This architecture is controlled using a parameterized Gaussian random function, wherein a non-uniform orientation distribution function restricts the sampled wave vectors to lie within user-defined cone angles. While our previous work was restricted to the four different spinodoid topologies proposed by Kumar et al. [2], in this work, we investigate the feasibility of altering the cone angle limits with the goal of generating topologies that can provide increased acoustical benefits. We systematically alter the cone angles with respect to the conventional orthogonal Cartesian basis and investigate their effect on the resultant cellular topologies. A select set of spinodoid structures are then 3D printed and tested using a normal incidence impedance tube. Our results show that spinodoid structures provide a rich design space for the development of porous noise reduction materials that can be tuned to achieve application-specific acoustical performance. [1] B. Wojciechowski and B. Sharma, “Acoustical properties of spinodoid porous structures,” J. Acoust. Soc. Am. 150(4), A148 (2021). [2] S. Kumar, S. Tan, L. Zheng, and D. M. Kochmann, “Inverse-designed spinodoid metamaterials,” npj Comput. Mater. 6(1), 1 (2020).
Acoustic prominence of verbal instructions in Parkinson's disease
Authors: Knowles Thea , Clayards Meghan , Cline Nathan
Published: April 2023

Talkers signal important information to listeners in part by manipulating prosodic prominence. In English, this is typically achieved by producing more prominent words with greater durations, intensity, f0, and hyperarticulation, though this tendency may be reduced in talkers with motor speech disorders. In the present study, older adults with and without Parkinson’s disease (PD) and dysarthria engaged in a simple instructional game activity in which they directed a research confederate to move around pictures on a board. Utterances were designed to manipulate prominence on stop-initial monosyllabic target words that differed in onset voicing and following vowel quality. Non-prominent words were repeated in the spoken instructions (“Move the pot above the chair, now move the [pot] above the box”), while prominent words contrasted with a minimal pair differing in onset voicing (“Move the pot above the chair, now move the [bot] above the chair”). Eleven people with PD and 11 age- and gender-matched controls participated. Overall, prominent words were longer, louder, and higher pitched, though control speakers modulated f0 to a greater extent than talkers with PD. Both groups modulated the amount of voicing during closure but not VOT as a means of increasing stop voicing contrasts in prominent words.
Crosslinguistic influence in bilingual production of clear speech
Authors: Jung Ye-Jee , Dmitrieva Olga
Published: April 2023

Clear speech, a listener-oriented speaking style adopted to mitigate communicative barriers, is often characterized by language-specific acoustic enhancement of phonological contrasts (Smiljanic and Bradlow, 2008; Cho et al., 2011). Previous work (e.g., Smiljanic and Bradlow, 2009) suggested a possibility that bilingual speakers’ L1 and L2 clear speech strategies could affect each other. The current study examined English and Korean clear speech produced by late Korean-English bilinguals (n = 30) living in the United States. Their clear speech produced in each of the two languages was compared with clear speech produced by either English (n = 20) or Korean (n = 20) monolinguals. Of specific interest was how English and Korean stop contrasts were realized and enhanced in clear speech with respect to the use of VOT and onset F0. The bilinguals enhanced the English voicing contrast in the same manner as English monolinguals, via asymmetrical lengthening of voiceless stops’ VOT. In Korean clear speech, bilinguals also lengthened VOT of the aspirated and lenis (long-lag) stops, whereas Korean monolinguals did not exhibit the same pattern. These findings suggest that Korean clear speech strategies produced by the bilinguals could be affected by their L2, due to their extensive exposure to the language.
Clear speech improves word segmentation in quiet and in noise: Evidence from visual-world eye-tracking
Authors: Guo Zhe-chen , Smiljanic Rajka
Published: April 2023

Listener-oriented hyperarticulated clear speech facilitates linguistic processing and cognitive functioning associated with speech perception under various listening conditions. Using the visual-world eye-tracking paradigm, we investigated whether clear speech also aids speech segmentation, or the discovery of word boundaries, and examined the dynamic time course of its effect. Native American English speakers (N = 77) heard sentences in which the target word (e.g., ham) was temporarily ambiguous with a longer unintended competitor (e.g., hamster) across a word boundary (e.g., She saw the ham starting…) while viewing images depicting the target, competitor, and unrelated distractors. Clear and conversational sentences were presented in quiet or in speech-shaped noise at +3 dB signal-to-noise ratio. Analysis of eye fixations to the images over time revealed that compared with conversational speech, clear speech facilitated the disambiguation of the target from the competitor even before the disambiguation point was reached. The facilitation was found in both listening conditions but was relatively delayed in noise. These findings suggest that speaking clearly improves word segmentation and reduces lexical competition especially in optimal listening conditions. The speech segmentation facilitation may partly underlie the clear speech benefits observed for other signal-dependent and relatively signal-independent linguistic and cognitive processes.
Perceptual effects of formant enhancement with the factors of phonetic type, listening conditions, and language experience of listeners
Authors: Li Mingshuang , Liu Chang
Published: April 2023

The second formant (F2) enhancement is a technique that aims to improve speech perception in adverse noise by amplifying the F2 of speech signals. The current study was to investigate whether F2 enhancement would improve speech identification with the factors of phonetic type (e.g., vowel and consonant), listening conditions (e.g., speech and nonspeech noise at moderately and challenging SNRs), and language experience of listeners (e.g., native and nonnative listeners), and whether the amount of perceptual benefit was dependent on these factors. Two groups of participants, English native and nonnative listeners, were recruited in this study. Identification of English vowels and consonants with and without F2 enhancement were measured in quiet, long-term speech shaped noise (LTSSN) and six-talker babble (6-TB) at the signal-to-noise ratios (SNRs) of −10 dB and −15 dB. Overall, significant improvements from F2 enhancement were found in both vowel and consonant identification for both native and nonnative listeners in various listening conditions. Furthermore, greater improvement was found at the SNR of -15 dB than at the SNR of −10 dB, as well as for nonnative listeners than native listeners in vowel identification. Meanwhile, the amount of benefit was generally comparable speech and nonspeech noise. These results indicate that F2 enhancement could improve phonetic identification in noise for native and nonnative listeners, showing a potential as a speech enhancement algorithm in challenging noise.
Speech-in-speech perception: The role of F0, rate, and rhythm
Authors: Fishero Sheyenne , Jongman Allard , Sereno Joan
Published: April 2023

Speech perception typically takes place against a background of other speech or noise. The present study aims to investigate the effectiveness of segregating speech streams within a competing speech signal, examining whether cues such as pitch that typically denote a difference in talker behave in the same way as cues such as speaking rate that typically do not denote the presence of a new talker. Native English speakers listened to English target speech within English two-talker babble of a similar or different pitch and/or a similar or different speaking rate to identify whether mismatched properties between target speech and masker babble improve speech segregation. Additionally, Dutch and French masker babble was tested to identify whether an unknown language masker improves speech segregation capacity and whether the rhythm patterns of the unknown language modulate the improvement. Individual differences in selective attention were also measured to determine whether they can predict speech segregation ability. This study aims to increase the understanding of speech perception in a more ecologically valid context and to identify whether there is a link between a cue’s potential to denote a new speaker and its ability to aid in speech segregation during competing speech perception.
Japanese pitch-accent identification accuracy by children with autism spectrum disorder
Authors: Shinohara Yasuaki , Uchida Mariko , Matsui Tomoko
Published: April 2023

A previous study demonstrated when Japanese speakers hear sine-wave speech carrying no fundamental frequency information, they rely on the first formant frequency for their pitch-accent perception, resulting in poor identification accuracy. However, when sine-wave speech is noise-vocoded, each formant becomes less audible, and Japanese speakers use other acoustic cues (e.g., duration and intensity), leading to better identification [Y. Shinohara, “Japanese pitch-accent perception of noise-vocoded sine-wave speech,” The 183rd Meeting of ASA, Nashville, TN (2022)]. The present study examined pitch-accent perception by children with autism spectrum disorder (ASD) for the same three stimulus types: natural recordings, sine-wave speech, and noise-vocoded sine-wave speech. Children with ASD often have enhanced auditory pitch perception for non-speech stimuli. However, since the present study used a pitch-accent word identification task, it was hypothesized that Japanese-speaking children with ASD would show less identification accuracy for all three stimulus types compared to age-matched typically developing children. Our preliminary results showed a significant difference in identification accuracy between the two groups. A detailed analysis of the results and the acoustic features of each stimulus type will be discussed.
Listener bias and intelligibility of unfamiliar varieties of a language
Authors: Kimura Kenzo S. , Levi Susannah V.
Published: April 2023

Speech intelligibility depends on a combination of the speech itself and of the listener. In terms of speech, unfamiliar varieties (such as foreign-accented speech or speech produced in an unfamiliar dialect) are generally less intelligible than speech produced in a variety that matches that of the listener. In terms of the listener, studies have found that listener experience affects intelligibility of unfamiliar varieties of a language. The current study explores the extent to which a listener’s biases toward globalization and immigration predict speech intelligibility. High and low predictability sentences from three men (US English, Scottish English, Mandarin-accented English) were mixed with background noise. Fifty L1 US English listeners first typed the final word of each sentence and were then asked to answer questions related to their views on globalism and nationalism. As expected, listeners were more accurate in the high compared to low predictability sentences. Surprisingly, the Mandarin-accented speaker was the most intelligible. A follow-up study with duration-normalized samples found the same result. Contrary to expectations, listener responses to the globalist-nationalist survey had no impact on intelligibility. This may suggest that difficulty understanding unfamiliar varieties of a language is not related to listener attitudes.
Bayesian detection and tracking of odontocetes in 3D from their echolocation clicks
Authors: Jang Junsu , Meyer Florian , Snyder Eric , Wiggins Sean , Baumann-Pickering Simone , Hildebrand John
Published: April 2023

To study behaviors of marine mammals in a nonintrusive manner, their bio-acoustical signals can be recorded by volumetric hydrophone arrays that provide time difference of arrival (TDOA) measurements for localization and tracking. Multi-target tracking (MTT) in 3-D using TDOA measurements from multiple sensors, however, must cope with non-linear measurement models and high-dimensional states. False alarms, missed detections and unknown data associations impose further challenges, often requiring human operators to annotate the data manually. We propose a data processing chain that automatically detects and tracks odontocetes from their echolocation clicks. The echolocation clicks are detected with a generalized cross-correlation that whitens the instrument noise. Two stages of tracking are performed using a tracking framework based on factor graphs and the sum-product algorithm (SPA). The odontocetes are first tracked in the TDOA domain to remove false alarms and then in the 3-D domain, fusing the tracked TDOAs across all sensors. To efficiently handle the considered non-linear and high-dimensional MTT scenario, particle flow is embedded in the SPA. According to simulation results, the proposed tracking method outperforms the existing approach using manual data annotation. Tracking of Cuvier’s beaked whales (Ziphius cavirostris), whose echolocation clicks are recorded by two volumetric hydrophone arrays, is demonstrated.
Comparison of manifold representations of sonar data
Authors: Kubicek Bernice , Sen Gupta Ananya , Kirsteins Ivars
Published: April 2023

There are many challenges in active sonar target recognition due to the dynamic nature of the environment, unknown target geometries, and various clutter present within the ocean. These factors combine and entangle the target features within the received response. This research assumes the informative and discriminatory acoustic target features lie on a low dimensional manifold and can be extracted using statistical and machine learning techniques. Linear techniques, such as principal component analysis and linear discriminant analysis, are useful for dimension reduction but will typically not accurately capture the underlying non-linearity within a dataset. Non-linear manifold learning techniques, such as T-distributed stochastic neighbor embedding and uniform manifold approximation and projection, are relatively recent techniques that create low-dimensional embeddings in an unsupervised fashion and can capture the non-linearity. Previously, persistent braid features have been reported in real sonar data1. Our objective here is to do comparison between these different manifold representations for both simulated data with a known ground truth and experimental active sonar data. [1] A. Sen Gupta, B. Kubicek, A. Christensen, and I. Kirsteins, “Geometric feature representation in active sonar signal processing,” OCEANS 2022—Chennai, 2022, pp. 1–5. [Work supported by NDSEG 2021 and ONR Grant No. N00014-21-1-2420].
Analysis of braid manifolds using uniform manifold approximation and projection
Authors: Christensen Andrew J. , Sen Gupta Ananya , Kirsteins Ivars
Published: April 2023

Autonomous sonar target recognition has been an ongoing challenge in the underwater signal processing community for many decades. Aspect-dependent target scattering and waveguide propagation causes target features to overlap, which increases the difficulty of constructing feature dictionaries. Current machine learning algorithms can suffer from an inability to track morphing target-specific features. Other ”black-box” machine learning algorithms produce results that are not explainable. We seek to extend previous work on creating feature representations using braid manifolds. Specifically, we use Uniform Manifold Approximation and Projection (UMAP) as a dimensionality reduction technique to search for underlying features that lay on a manifold. UMAP is an unsupervised learning algorithm that is built upon Riemannian geometry and fuzzy simplicial sets. The low dimensional representation embedding that UMAP produces is computed using both stochastic approximate nearest neighbor search and stochastic gradient descent with negative sampling. The performance of UMAP embeddings will be compared against other common dimension reduction algorithms and evaluated using various classifiers. [The authors would like to thank the Office of Naval Research for funding under Grant No. N00014-21-1-2420 and the University of Iowa.]
E90 round-robin—Status and path forward
Authors: Way Evelyn , Raley Michael
Published: April 2023

A good understanding of the uncertainty of a test method is necessary to interpret the results of said test. The ASTM E90 test has many potential sources of variation that can lead to significant uncertainty in the test results, but this uncertainty is not well documented in the precision and bias statement within ASTM E90. The current precision and bias statement provides some limited repeatability data for a wood joist floor and a concrete slab and only provides reproducibility data for the ASTM E1289 reference specimen. The E1289 reference specimens are simple steel plates in single and double-layer configurations that yield STC ratings far below those of the wall and floor/ceiling assemblies that are commonly tested. The authors are in charge of a new round-robin that aims to provide more detailed repeatability and reproducibility data using common wall designs with STC ratings in the range more commonly seen in building code requirements and design guidelines. In this presentation, the authors will cover their proposed plan for the round-robin and will give an update on its status.
International green construction code (IgCC)/ASHRAE 189.1: History and use of acoustical control section
Authors: Miller-Klein Erik , Koukounian Viken
Published: April 2023

This seminar will provide historical context on the current Acoustical Control section 801.3.3 in the International Code Council's International Green Construction Code (IgCC) is based on the ASHRAE Standard 189.1 Standard for the Design of High-Performance Green Buildings. This includes a detailed review of the current language and application, and guidance on the best way to design and commission to this standard.
Estimating populations of dense animals using acoustics
Authors: Eddington Valerie M. , White Easton , Kloepper Laura
Published: April 2023

Acoustic censusing methods offer an efficient and noninvasive method to monitor populations of dense aggregations of animals on a large scale. Large, dense colonies of bats are difficult to census, and current monitoring methods are often invasive and time consuming. Using acoustic recordings collected during emergence, we developed a linear regression model that uses multiple measures of acoustic energy to estimate the number of bats per second. The model was trained using data from audio recordings collected at seven cave locations and two species of bats, Brazilian free-tailed bats (Tadarida brasiliensis) and gray bats (Myotis grisenscens). Visual counts from synchronized thermal videos were used to ground truth the model. Environmental factors, such as distance from microphone to emergence, were integrated to create flexible model that is widely applicable across species and habitats. This method can be extended to other species that vocalize in large aggregations, such as sea birds and frogs. Ultimately, this model can be integrated into autonomous monitoring stations to monitor species in real time. It is imperative that efficient and noninvasive methods for monitoring bat populations are developed to increase population data available for informing crucial management decisions.
Ultrasound multifrequency strategy applied to the estimation of lung surface roughness
Authors: Mento Federico , Perini Matteo , Malacarne Ciro , Demi Libertario
Published: April 2023

There exist lung pathologies (e.g., COPD) characterized by an enlargement of air-spaces. Since air-spaces of different sizes can generate different levels of roughness along the lung surface, estimating the roughness may provide an indirect characterization of the lung state. This study, thus, analyzes the possibility to develop a multi-frequency quantitative approach forthe estimation of lung surface roughness. Specifically, the presented technique focuses on the analysis of ultrasound image intensity variation along the lung surface as a function of frequency. In silico and in vitro results will be presented. First, k-wave was used to study the effect of different levels of lung surface roughness on numerically generated ultrasound images. Data were simulated with center frequencies from 1 to 10 MHz (bandwidth = 0.5 MHz). The same acquisition strategy was then used to acquire data from 3D printed steel models, made to mimic an acoustic interface with high reflection coefficient (similar to air-tissue interfaces) and realized with different levels of roughness. As expected, due to diffuse scattering, the increase of the “air-spaces” diameter is linked to a decrease of the frequency at which a significant drop of intensity was observed. This ultimately provides a way to indirectly estimate lung source roughness.
Quantitative lung ultrasound spectroscopy, an in vivo clinical study conducted over 101 patients
Authors: Mento Federico , Perpenti Mattia , Barcellona Giuliana , Torri Elena , Perrone Tiziano , Demi Libertario
Published: April 2023

Lung ultrasound (LUS) is widely adopted to assess the state of the lung surface. However, as standard ultrasound imaging assumptions are unmet in the lung due to the presence of air, essentially this organ cannot be anatomically investigated. Indeed, LUS is mainly based on the analysis of imaging artifacts (horizontal and vertical). Of particular interest is the analysis of vertical artifacts, as they correlate with several pathologies. More specifically, their dependence on frequency was demonstrated to carry important diagnostic information capable to improve LUS specificity. In this study, a new dataset was generated acquiring raw radiofrequency (RF) data from 101 patients (affected by different pathologies, e.g., COVID-19 pneumonia and cardiogenic edema). The ULA-OP research platform was used to collect the data, and a multifrequency approach implemented on both linear and convex probes was adopted. Ultrasound data were thus acquired utilizing orthogonal sub-bands with a 1-MHz bandwidth and with different center frequencies (2–6 MHz). About 12 000 and 3600 multifrequency frames were acquired with convex and linear probes, respectively. Clinical parameters (e.g., FIO2 and LDH) were also stored for all patients. During this meeting, the dataset will be presented together with preliminary results, and its potential applications discussed.
Effectiveness of transferring ultrasound deep learning models from adults to pediatrics for frame based pneumonia classification
Authors: Thompson Russell , Khan Umair , Li Jason , Etter Lauren , Camelo Ingrid , Pieciak Rachel , Castro-Aragon Ilse , Setty Bindu , Gill Christopher , Demi Libertario , Betke Margrit
Published: April 2023

Hand-held ultrasound devices are emerging as a promising intervention to aid in diagnosing deadly early childhood pneumonia in the developing world. Lung ultrasound (LUS) data, however, can be difficult to read and interpret accurately, and thus require trained professionals. A variety of deep learning (DL) models have been developed to aid professionals in this task, but the difficulty curating quality training datasets limits the generalization capabilities of these models. To combat this data scarcity, we utilized a variety of DL models trained on LUS data collected from adult COVID-19 patients in Italy and were able to apply transfer learning to increase pneumonia related imaging pattern classification in LUS data from children and infants in rural Zambia. In this regard, we found that transfer learning significantly increased frame classification F1 performance as compared to training models from scratch. These findings indicate the promising potential for developing generalizable AI for LUS classification in diverse contexts given limited data. This analysis demonstrates that DL models effectively transfer their capabilities when fine tuned on a new population demographics, allowing the possibility to clinically deploy these models without the need to acquire large amounts of new data.
Value of multidisciplinary peer mentoring
Authors: Haworth Kevin J. , Fichtenbaum Carl J. , Smith Eric P. , Zimmerman Nives , Powers-Fletcher Margaret V.
Published: April 2023

Biomedical acoustics is a multidisciplinary field. As such, both the scientific field and its members have the potential to benefit from the interactions and cross-fertilization of different subfields. Peer mentoring groups (PMGs) can promote multidisciplinary interaction. A PMG involves the intentional, structured, and consistent interaction of individuals at similar career stages. The horizontal organization of a PMG can promote a safe and supportive environment, enabling greater knowledge sharing. PMG knowledge sharing is bidirectional, providing benefits to all participants and an opportunity to leverage diversity, which yields outcomes. In one example from our institution, a research-active group of junior faculty from different academic divisions within a department of internal medicine met biweekly to review, on a rotating basis, active grant applications, critiques of rejected proposals, and career development challenges. Another example was an interdepartmental graduate program where doctoral students studying a range of fields (e.g., infectious diseases, cancer, metabolism, and cardiovascular disease) engaged in a journal club and a seminar series. In both settings, participants had the opportunity to benefit from the recognition of thematic and methodological overlap in their otherwise disparate studies, which promoted best practices in research. In summary, PMGs provide value to both participants and the field.
Direct ink writing of textured piezoelectric ceramics
Authors: Fellabaum Chloe , Eadie Christopher , Fanton Mark
Published: April 2023

Textured ceramics are often formed via tape casting in order to align platelet particles in the preferred direction, allowing the ceramic to have properties approaching those of single crystals without the complexities of growing such a crystal. However, tape casting produces significant waste material, as flat plates are machined to produce the desired geometries, e.g., rings. Additive manufacturing reduces these issues by allowing the complex geometries to be formed in the green state, thus reducing waste and improving design freedom. This presentation will discuss progress to-date on direct ink writing (DIW) of textured PMN-PZT. The focus will be on the methodology used to develop a suitable paste for printing. Development of a stable, shear thinning paste with a quick recovery time is critical. Zeta potential and rheological data were collected as a function of pH and other relevant slurry parameters such as percent solids loading and binder content. Sintered filaments and bulk parts were characterized to evaluate the efficacy of template alignment in the process as a function of slurry rheology, nozzle geometry, and print parameters.
Template alignment optimization in additively manufactured piezoelectric ceramics
Authors: Cowen Benjamin , Eadie Christopher , Lindau Jules , Mauro John
Published: April 2023

Sonar transducer performance is greatly impacted by the microstructural alignment of the ceramics from which they are fabricated. Textured ceramics are a desirable material source for these parts because their deliberately aligned microstructures allow for tailored anisotropic properties that rival those of single crystal ceramics, but they also maintain the mechanical robustness and bulk manufacturability of polycrystalline ceramics. Current methods for manufacturing textured ceramics, e.g., tape casting, severely limit design freedom and require excess material waste, and so the advantage of texturing has not been fully realized. This study is focused on the enhancement of direct ink writing of textured ceramics. Direct ink writing is an additive manufacturing (AM) technique that enhances design freedom on a macro and micro scale and reduces waste by producing near-net shape textured ceramics. However, shear stresses during the AM process affect the microstructural alignment of the ceramic in an extremely complex manner that is difficult to control directly. This study first validates a novel alignment metric, derived from a computational fluid dynamics model that simulates the printing process, against real-world data. Then, an optimization algorithm is used to maximize alignment with respect to the nozzle geometry.