bluuebunny/crossref_metadata_2025 huggingface dataset:
Spectral degradations in the TIMIT, QuickSIN, NU-6, and other popular bandlimited speech materials
Authors: Monson Brian B. , Buss Emily
Published: April 2023

Many popular speech corpora were recorded decades ago using transducers, recording techniques, or post-processing techniques that resulted in spectral degradations. The use of such materials very likely has consequences for measures of speech perception, but this is not often considered in studies that use these materials. We analyzed several of these popular corpora to ascertain spectral degradations that may be present. Spectral degradations we frequently observed included limited extended high-frequency (EHF) (>8 kHz) content, and, for a few corpora, substantial low-frequency roll-off <500 Hz. Two corpora analyzed here, the TIMIT/PRESTO and NU-6, exhibited both high- and low-frequency degradations. Such spectral degradations will likely have an effect on behavioral measures because they do not match the high-fidelity speech signals listeners encounter in their everyday lives. This should be considered when selecting stimuli for speech perception experiments. [Work supported by NIH Grant R01-DC019745]
Envelope-following responses to single and double amplitude modulation: No correlate of modulation masking
Authors: Wojtczak Magdalena , Goh PuiYii , Oxenham Andrew J.
Published: April 2023

Magneto- and electroencephalographic (M/EEG) measures of neural responses to speech and other natural sounds provide a noninvasive window into the neural tracking of temporal dynamics of natural sounds. However, the interpretation of these measures and their relation to perception remain unclear. In this study, amplitude modulation (AM) of a low-pass noise carrier (cutoff 4 kHz) was used to measure EEG envelope following responses (EFRs) for two AM rates presented simultaneously or in isolation. The spectral separations between the two AM rates were selected to produce varying degrees of perceptual modulation masking. The AM rates used spanned the range from 8 to 203 Hz, reflecting cortical and subcortical EFR generators. For double-rate AM, the EFRs had two distinct spectral peaks, corresponding to the component AM rates. In all conditions, the peak EFR amplitudes for two simultaneous AM rates did not differ significantly from those presented singly, even when the two rates produced significant perceptual masking. The results show that EEG measures of neural responses synchronized to temporal envelope fluctuations fail to reflect the important perceptual phenomenon of modulation masking. [Work supported by NIH R01 DC012262 (Oxenham) and R01 DC015987 (Wojtczak).]
Spatial attentional behavior analysis based on cognitive style during speech-in-noise task
Authors: Takeuchi Akira , Shim Hwan , Choi Inyong , Kim Sungyoung
Published: April 2023

We designed a spatial selective attention task to investigate a listener’s speech understanding ability in various masking noise conditions. The masking noise stream is music and non-intelligent speech combined sound which was played from the front-right and back directions. The target speech stream which has an auditory cue “Ready,” following color and number information, for example, ‘Ready Blue Five,’ was played from the front-left direction. A listener’s attentional ability was evaluated through the accuracy of the correct number and color selection in each condition of various SNRs and the spatial location of the masker. We formed two subject groups showing distinct cognitive styles, independent-analytic and interdependent-holistic, from a pre-experimental analysis. The analysis of variance (ANOVA) evinced a significant interaction between the group and SNR. Moreover, the independent-analytic group appeared to maintain their attention regardless of spatial location while another group scored poorly for the rear-positioned masker. Specifically, when the task got difficult with lower SNR conditions, this discrepancy between the two groups became significant. From these discussions, this study supports that individual differences associated with subconscious cognitive constructs influence speech-in-noise understanding ability.
Visual phonemic knowledge and audiovisual speech-in-noise perception in school-age children
Authors: Lalonde Kaylah , Dwyer Grace A.
Published: April 2023

Our mental representations of speech sounds include information about the visible articulatory gestures that accompany different speech sounds. We call this visual phonemic knowledge. This study examined development of school-age children’s visual phonemic knowledge and their ability to use visual phonemic knowledge to supplement audiovisual speech processing. Sixty-two children (5–16 years) and 18 adults (19–35 years) completed auditory-only, visual-only, and audiovisual tests of consonant-vowel syllable repetition. Auditory-only and audiovisual conditions were presented in steady-state, speech-spectrum noise at individually set SNRs. Consonant confusions were analyzed to define visemes (clusters of phonemes that are visually confusable with one another but visually distinct from other phonemes) evident in adults’ responses to visual-only consonants and to compute the proportion of errors in each participant and modality that were within adults' visemes. Children were less accurate than adults at visual-only consonant identification. However, children as young as 5 years of age demonstrated some visual phonemic knowledge. Comparison of error patterns across conditions indicated that children used visual phonemic knowledge during audiovisual speech-in-noise recognition. Details regarding the order of acquisition of viseme will be discussed.
A new psychophysical paradigm for measuring distortion products
Authors: Ahadian Babak , Berg Bruce
Published: April 2023

A unique contribution of this work is the demonstration that distortion product (i.e., Cubic difference tone (CDT)) effects can be systematically investigated with a discrimination task. Much of our knowledge about the perceptual effects of distortion products has been obtained with probe-tone, cancellation experiments, which are cumbersome and require highly trained, knowledgeable listeners. In this 2IFC discrimination study, the standard interval consists of two primaries, f1 and f2, having the same amplitude and phase. For the two experimental conditions, the signal interval consists of a change in the phase of f2 to either π/2 or π. A third tone, f3, was added to both intervals at the frequency of cubic distortion tone (CDT). The amplitude of f3 is titrated with an adaptive threshold procedure. In order to acquire data relevant to the interaction between f3 and the CDT, the phase of f3 was varied across conditions. As predicted, the phase difference of π between the two primaries lowered the threshold by as much as 10 dB compared to a phase difference of π/2. This gain in sensitivity improves the precision of the methodology in estimating the phase and the amplitude of CDT in psychophysical tasks.
Young Pashtun L1 speakers' laryngeal contrast and voicing variation in Korean word-initial stops production
Authors: Yeom Soowon
Published: April 2023

While age proved to have a critical influence on learning L2 phonology, the reason behind it is yet controversial. (brain maturation, LOR, quality l2 input, crib or sequential bilingualism, etc.) This paper examines 6 young people in the same household using Pashtun as their L1. As the elder children arrived in Korea at ages 10, 8, 6, and 3 respectively, the younger two were born in Korea now aged 10 and 8. All family members have equal LOR(10 years except for the youngest), equal L1, and equal L1 and L2 use extent in the home. Examining the differences between VOT and f0 production in these young people will clarify some of the explanations behind the age effects. Moreover, the data reveals the unique L1 transfer phenomena. While Pashtun is a true voicing language, Korean is an aspirating language where all 3- way contrast stops have positive VOT values. This can lead the young people to produce word-initial Korean stops in intersonorant positions with a marked voicing-ratio and to produce allophones that neither exists in their L1 nor in L2 such as voiced aspirated stop sounds ( bɦ, d̪ɦ, gɦ). This paper will also examine whether these young people’s VOT and f0 productions would align with the current tonogenesis like sound change in Korean. This paper used picture naming tasks with easy words instead of reading non-words to not test their grapheme-phoneme correspondences. Each person produces 9 phonemes of word-initial Korean stops (3-way laryngeal contrasts in 3 POA) both in the position in isolation and carrier sentence.
Prosodic variation in intelligible L2-accented speech: Using acoustic measures to predict listening effort
Authors: Altmiller Ruth , Van Engen Kristin J.
Published: April 2023

Despite the relative ease with which listeners understand spoken language in their daily lives, speech perception is a complex task that becomes challenging in certain conditions, such as listening to speech in an unfamiliar second language (L2) accent. In the current study, we use pupillometry data from McLaughlin and Van Engen (2020) to ask whether prosodic variation predicts listening effort for L2-accented speech. In that study, L1 speakers listened to L1- and L2-accented English sentences. The pupillary response was larger for the L2-accented speech, even though it was fully intelligible. We hypothesize that prosodic differences in L2- versus L1- accented speech may account for such differences in listening effort for fully intelligible speech. To test this, we apply four acoustic measures to each of the stimuli used in the experiment. The first two measures, wiggliness and spaciousness (Wehrle et al., 2018), quantify the number and degree of F0 contour changes across each trial. The remaining two measures are relative word duration (Baker et al., 2009) and vowel pitch (Li & Shuai, 2011). We will use these trial level measures as fixed effects in Growth Curve Models to test the extent to which prosodic deviation predicts pupillary responses.
The effects of social manipulation of talkers on heritage bilingual speech perception
Authors: Gavino Maria F. , Goldrick Matthew
Published: April 2023

The social information listeners are given about a talker affects their perception. For example, when speech is embedded in noise, L1 English listeners are more likely to accurately perceive a talker when they are told the talker is a native versus non-native speaker, even though it is the same acoustic signal across the two conditions. Among other factors, this effect has been attributed to listeners (inappropriately) relying on prior experiences rather than the acoustic information, and/or listeners devoting less attention to speech when listening to stigmatized accents. The current study examines whether this social information similarly impacts English-dominant Spanish heritage bilinguals’ perceptual processes. 112 Mexican-American Spanish heritage bilinguals transcribed speech in noise in English-only and Spanish-only blocks. In each block, there were two talkers of different genders associated with native or non-native social information. Results show that listeners perform significantly better in their dominant language, however, did not reliably perform better when told a talker was a native speaker of the language they were perceiving. This suggests heritage bilingual listeners adopt a different approach to heritage bilingual speakers, relying more on the acoustic signal and/or better attending to speech (reflecting a lack of stigmatization of L2 speech or talker-listener alignment).
Accent rating of noise- and tone-vocoded foreign-accented speech
Authors: Sidhu Jaskirat , Xu Li , Yang Jing
Published: April 2023

There are abundant acoustic-phonetic cues in speech signals for listeners to encode talker identity. However, speech signals in the real world are always less optimal due to various adverse listening sources. Vocoded speech is one type of simplified signal that has less spectral and/or temporal information in comparison to normal speech. The purpose of this study is to examine whether and how listeners’ judgment of talker accent is affected by noise and tone vocoding. Twelve Mandarin-accented English speakers with varying degree of accentedness and two native English speakers were recorded reading “The Rainbow Passage.” The recorded speech samples from each talker were segmented into small sections that were randomly selected for noise- or tone-excited vocoder processing into 1, 2, 4, 8, and 16 channels. The vocoded and unprocessed speech samples were randomly presented to a group of normal-hearing, monolingual English listeners for accent rating. The listeners judged the degree of talker accent on a 9-point Likert scale with “1” representing no accent and “9” representing extremely strong accent. The data are still in the process of being collected and analyzed. Results and implications of the present study will be discussed.
Age differentially impacts monolingual and bilingual listeners’ understanding of English speech in noise
Authors: Phillips Ian , Bieber Rebecca E. , Ellis Gregory M. , Brungart Douglas S.
Published: April 2023

Some bilinguals may perform worse understanding speech in noise (SIN) in their second language (L2) compared to monolinguals. Poorer performance has been found mostly for late bilinguals (L2 acquired after childhood) listening to sentences containing linguistic context, and less so for simultaneous/early bilinguals (L2 acquired during childhood) and when testing context-free stimuli. However, most studies tested younger participants–little is known about interactions with age. This study addresses this gap by measuring context-free SIN understanding via the Modified Rhyme Test in over 2,000 normal-hearing young and middle-aged bilingual and monolingual adults (ages 18–58; 23% bilinguals, all L2 English). Data collection is ongoing. Interim analyses reveal an interaction of age and group. Word recognition accuracy decreased as age increased for simultaneous and early bilinguals, but was stable for monolinguals and late bilinguals (though worse for bilinguals than monolinguals). Response time was faster for monolinguals but all groups slowed with increasing age at similar rates. These findings suggest an exaggerated age effect for bilingual SIN understanding across early and middle adulthood. [The views expressed in this abstract are those of the author(s) and do not necessarily reflect the official policy of the Department of Defense or the U.S. Government.]
The cognitive demands of adverse listening conditions for monolingual and bilingual listeners: A pupillometry study
Authors: Carraturo Sita , Chen Samantha , Van Engen Kristin J.
Published: April 2023

Bilinguals typically underperform relative to monolinguals in speech-perception-in-noise tasks. However, there is little data comparing bilinguals and monolinguals in other types of difficult listening conditions. Furthermore, such differences are typically investigated using off-line intelligibility accuracy scores, which do not necessarily reflect differences in on-line speech processing. In the current study, pupillometry was used during sentence recognition tasks to index cognitive processing load. Monolingual English listeners and English-dominant simultaneous bilingual listeners heard English sentences in four conditions: American-Accented in Quiet, Turkish-Accented in Quiet, American-Accented in Noise, and Face Mask-Attenuated American-Accented in Quiet. Differences in pupil dilation between groups are expected in the latter three conditions. Data collection is on-going, but preliminary results (N = 40) show bilinguals exert more cognitive effort than monolinguals across all conditions.
The visual analogue scaling (VAS) task as a pre-instructional assessment in tailoring the L2 phonetic training paradigm
Authors: Lee Jieun , Park Hanyong
Published: April 2023

Our previous research has shown that we can predict which learners will benefit more from phonetic training to learn non-native phonological contrasts using the Visual Analogue Scaling (VAS). In this study, we adopted the VAS as a pre-instructional assessment to identify less likely-to-be successful learners and provided a pre-training to see whether such preparations would benefit those learners. We targeted naive English learners of Korean learning the Korean lenis-aspirated stop contrast who had to learn to use f0 cues (secondary cue in English stop voicing contrast) as a primary cue for successful learning. Using the VAS task with English stimuli, we identified participants with low f0 sensitivity. We gave the cue-attention switching training (CAST) to enhance their f0 sensitivity before providing three phonetic training sessions for the target contrast. Results showed the positive effects of CAST. Participants with low f0 sensitivity demonstrated a similar level of achievement in learning as participants with high f0 sensitivity and showed more native-like f0 cue utilization in identifying the target contrast than low f0 sensitivity participants who received training without CAST. Our study highlights the importance of considering individual differences with appropriate assessments and tailoring the training paradigm accordingly to maximize possible learning outcomes.
L1 category precision hypothesis in L2 production: Korean learners’ English front vowels
Authors: Oh Sujin , Park Hanyong
Published: April 2023

It has been hypothesized that learners with more precisely defined categories in their native language (L1) are better at learning nonnative sounds in a second language (L2). Some perception studies have supported this hypothesis, but not many production studies have been conducted. Our study aims to fill this gap. Focusing on front vowels in F1/F2 acoustic space, we calculated compactness scores of L1 vowels and distances between learners’ and native speakers’ productions to operationalize category precision and L2 accuracy, respectively. Then, we examined whether learners with a lower compactness score would produce L2 vowels with a closer distance. The learners’ productions were taken from a corpus containing native Korean speakers’ reading and retelling of the North Wind and the Sun in Korean and English and comparable native English speakers’ productions from ALLSSTAR corpus. Results showed that learners with lower compactness scores produced more accurate English /i/ and /ɪ/, but not for /ɛ/ or /æ/, which partially supports the hypothesis's application to L2 production. We speculate that the merger between /e/ and /æ/ in Korean, the Northern Cities Vowel Shift in English, and/or perceptual mapping between native and L2 categories are responsible for the English non-high vowel results.
The neurophysiological responses of music processing in bilingual teenagers
Authors: Guo Sharry , Diaz Andreas , Shafer Valerie , Bidelman Gavin , Jackson Tyreek , Yu Yan H.
Published: April 2023

The association/dissociation between music and language processing has long been a matter of debate. Musicians and tonal language speakers are more sensitive to pitch differences than nonmusicians and nontonal language speakers. Bilingual experience modulates auditory processing of sounds, but it is unclear whether and how bilingual experience affects music processing. This study examines music processing in bilingual teenagers from Mandarin (a tonal language) households and those from non-tonal language households. The central question is whether bilingual experience enhances auditory processing similarly regardless of the specific language, or whether the influence of language on music processing is language specific. Event-related potential (ERP) responses were recorded from 65 scalp sites. An oddball paradigm with six types of music changes (intensity, pitch, rhythm, timbre, slide and location) was presented. Preliminary results did not support the general bilingual advantage theory, but did support the language-specific enhancement of auditory processing.
Thing or sing: Modeling the phonetic variation of the interdental fricative /θ/ in accented English
Authors: Wang Fenqi , Deng Delin , Wayland Ratree
Published: April 2023

Chinese learners of English tend to pronounce the English interdental fricative /θ/ as [s] because it is absent in Chinese (Rau et al., 2009). To investigate the phonetic variation of the interdental fricative /θ/, this study extracted the first four spectral moments of the target fricatives [θ] and [s] from fricative-initial words in an L2 English speech corpus, and then analyzed them using generalized additive mixed-effects models (GAMM) and random forest classification. The corpus we used contains 31.6 hours of recordings from 389 Chinese speakers from different regions in China (Chen et al., 2019). Classification accuracy rates suggest variation in the production of /θ/ among Chinese learners of English from different Chinese dialectal regions, and the computation of conditional feature importance sheds light on the relative impact of acoustic measurements in predicting the fricatives in accented English. The findings of this study can provide robust empirical evidence on the phonetic variation of the interdental fricative /θ/ in accented English by Chinese learners of English and shed light on a new way to probe into the phonetic variation in non-native speech.
Easy come, easy go: Examining the stability of lexically guided perceptual learning over time
Authors: Hodges Emma C. , Cummings Shawn N. , Theodore Rachel M.
Published: April 2023

Listeners can use lexical information to accommodate ambiguity in speech input. Some evidence suggest that lexically guided perceptual learning persists over time. However, other evidence suggests that lexically guided perceptual learning attenuates throughout the test session, consistent with distributional learning that occurs given exposure to the test stimuli. Here we test the hypothesis that lexically guided and distributional learning may operate over different time scales. During exposure, listeners heard spectral energy ambiguous between /ʃ/ and /s/ in a lexically-biasing context. At test, listeners categorized tokens from an ashi-asi continuum. Test duration was manipulated between subjects to be either brief or long. Approximately 24 hours later, both groups completed a second test phase. The results to date show (1) robust lexically guided perceptual learning at the first test, (2) attenuation of learning for the long duration compared to the short duration test group at the first test, and (3) no robust evidence of lexically guided perceptual learning for either group at the second test. If these results hold in the full sample to be tested, then they would suggest that lexically guided perceptual learning is best characterized as dynamic adaption to recent input that dissipates within a day.
Linking lexically guided perceptual learning to statistical patterns in speech input
Authors: Cummings Shawn N. , Choi Jeung-Yoon , Shattuck-Hufnagel Stefanie , Theodore Rachel M.
Published: April 2023

Listeners use lexical information to modify the mapping between speech acoustics and speech sound categories. Despite convention to consider lexically guided perceptual learning as a binary outcome, the magnitude of the learning effect varies in the extant literature. We hypothesize that graded learning outcomes can be linked, in part, to statistical characteristics of the to-be-learned input, consistent with the ideal adapter theory of speech adaptation. Following standard methods (i.e., waveform averaging to create ambiguous variants), a lexically guided perceptual learning stimulus set for the /ʃ/-/s/ contrast was created for each of 16 talkers, yielding variability in the statistical cues specifying this contrast across talkers. Experiment 1 will (a) measure lexically guided perceptual learning for each talker, (b) identify input characteristics that are associated with learning magnitude, and (c) examine whether a computational instantiation of the ideal adapter theory can model the input-learning link. Experiment 2 will provide a confirmatory test of the patterns observed in Experiment 1 by manipulating the to-be-learned input holding talker constant. The results will provide a critical test of the ideal adapter framework for speech adaptation, thus informing an understanding of the mechanisms that allow listeners to solve the lack of invariance problem for speech perception.
Interpretation of speech rhythm: Speech error, speech rhythm, and speech proficiency
Authors: Park Seongjin
Published: April 2023

It has been well-known that second language learners are affected by their first language when producing their L2. For speech rhythm, it has been suggested that L2 speakers are affected by L1 speech rhythm (e.g., Korean learners of English produce English without reducing the duration of unstressed vowels), and the effect is greater when speakers are beginner or intermediate-level language learners. This study, however, suggests that the direction of the effect is not always the same as researchers expected, and shows how easily speech rhythm is influenced by speech errors. The result of this study shows the relationship between the type of speech errors and speech rhythm metrics, and how that affects the perceptual proficiency of L2 speakers as well as L1 speakers. Future studies will be conducted to examine the way to infer the type of speech errors using speech rhythm metrics.
Accommodating accents: Linking rapid adaptation and continuous learning over a month
Authors: Xie Xin , Kurumada Chigusa
Published: April 2023

Perceptual difficulties associated with unfamiliar talkers or accents are known to dissipate—sometimes within minutes of exposure. Two major questions remain open: (a) How does adaptation commence within the initial moments of an encounter?; and (b) How does the adaptation continue via repeated exposure to the same talker/accent? The current study addressed these questions by assessing incremental changes of native English listeners’ recognition of L2-accented speech (Mandarin-accented English) over two timescales: within the first few minutes and over a month. Specifically, we tested how native listeners’ recognition of a word-final /d/, which is initially confusable with a /t/, may change over these two time scales. The target versus control groups both heard Mandarin-accented speech, but only the target group heard words containing the critical contrast. Using a new repeated exposure-test paradigm, trajectories of adaptation were assessed three times within an initial session (Exp.1) as well as over five sessions spanning a month (Exp.2). In addition to mixed-effect analysis on the effect of exposure at a group level (i.e., target versus control), computational simulations of distinct mechanisms (cue-based normalization, Bayesian belief updating, changes of decision-making criteria) will examine whether adaptation seen across the timescales can stem from the same mechanism.
Acoustic convergence of voicing when shadowing an unfamiliar language and a non-native accent
Authors: Hutchinson Amy , Zhou Alexis N. , Seo Yuhyeon , Dmitrieva Olga
Published: April 2023

Previous work has established that speakers are able adjust the acoustic properties of their speech in order to mimic their interlocuter or speech model with whom they share a native language (e.g., Pardo, 2013). However, it is less clear whether convergence to accented speech and/or unfamiliar languages is also a possibility. The goal of the present study is to investigate acoustic convergence between two groups of native English speakers (N = 15 in each group) and a speaker of Russian-accented English versus a speaker of Russian. The study consisted of four experimental phases: baseline, exposure, shadowing, and post-test. Participants in both groups shadowed acoustically identical material, although one group was informed that they were hearing Russian-accented English words (ACC-ENG condition), while the second group was told that they were shadowing Russian words (RUS condition). Initial analysis of the VOT durations of participants’ voiceless stops indicated that only participants in the RUS group converged towards the models’ shorter VOT during shadowing, although this convergence did not generalize to participants’ pronunciation of English words during the post-test. Additional data analysis is ongoing. This presentation will also discuss results with respect to their implications for theories of speech accommodation and non-native speech learning.
Exploring bilingual effects on iconic memory using 2D and 3D visuospatial recognition tasks
Authors: Chang Wu Cinty , Spinu Laura
Published: April 2023

Numerous studies indicate positive effects of bilingualism on cognition, mostly found in the domains such as attention, inhibitory control, auditory processing, and memory (Bialystok, 2018; Krizman et al., 2012; Spinu, 2022). While most studies focusing on memory have explored differences between monolinguals and bilinguals in working memory and, more recently, in auditory sensory memory, the question of whether bilingualism also affects iconic memory remains understudied. In this study, we explore whether bilingual experience results in enhanced iconic memory in the form of gestural, visuospatial recognition. We present bilingual and monolingual participants from NYC (n = 40) with thirty sets of foreign characters, one at a time, then ask them to recall which characters they have seen before from a list of characters that includes novel ones bearing high resemblance with previously shown characters. Second, we display to the same participants thirty sets of ASL signs (15 2D images and 15 3D short videos), with high resemblance as well, utilizing the same method to evaluate their gestural and visuospatial abilities in iconic memory. While the experiment is currently underway, the findings will shed more light on whether the benefits associated with additional language experience extend to non-linguistic domains, likely resulting from enhanced cognitive function mechanisms.
An experimental study of mobile underwater acoustic channels and their impacts on mobile acoustic communications
Authors: Liu Zhiqiang
Published: April 2023

Most underwater acoustic communication schemes have implicitly assumed limited platform mobility and their performance tends to suffer considerably when the platform is in high motion. To gain insight into the effects of high platform mobility, a sea-going experiment was recently conducted. In the experiment, two channels are set up. One is a stationary channel between a fixed source and a fixed receiver. The other is a highly mobile channel between a fixed receiver and a source towed in a circle at a speed of 6 knots. The two channels are directly compared in terms of four key channel parameters changes that matter most to the performance of acoustic communications, namely, channel coherence, path loss, Doppler scaling factor and carrier frequency offsets. A channel probing signal is judiciously designed to enable reliable estimation of those parameters at high resolution in time. This paper will provide the details of this sea experiment, including its design, setups and execution, and report interesting findings.
Exploring propagation delay and mobility in underwater acoustic networks
Authors: Wang Ruoyu , Zheng Yahong R.
Published: April 2023

This work investigates the impact of mobility on underwater acoustic communication networks where the propagation delay is comparable to or larger than the packet duration. A new simulator is proposed to implement the acoustic communication timing model when the nodes are mobile or static. Synchronous and asynchronous Medium Access Control (MAC) protocols are employed with ALOHA, TDMA (Time-Division Multiple Access), and Artificial Intelligent (AI) agent nodes. Extensive simulations are conducted to study the throughput of a MAC network where a large number of source nodes transmit to a single sink node. A network of 2–15 source nodes are assumed to be randomly located in a 1500 m cubic space and some of the nodes are moving in random directions at 2–4 m/s speed. The simulation results show that the asynchronous MAC protocols achieve much higher throughput than the synchronous protocols by allowing time slots to be much shorter than the maximum propagation delay among nodes and allowing asynchronous transmission time. High mobility of a few mobile nodes also favors asynchronous protocols and improves the network throughput in a manner similar to an AI agent.
Do we really need to do this?
Authors: Ehnert Jesse
Published: April 2023

In the acoustical consulting profession, our task is usually to provide recommendations based on our expertise and experience on projects involving existing problems or new facilities looking to avoid problems and achieve sonic success. This does not occur in a vacuum as practicalities and budget usually loom in the shadows (or out in the open). Inevitably, clients often question and sometimes even push back on our guidance. This presentation will discuss certain areas where these situations are prone to arise, with examples, and will endeavor to explore the nuances of the question: “do we really need to do this?”
Challenging rules of thumb to redefine flexibility
Authors: Kanter Shane J. , Giegold Carl P. , Dulworth Nicolaus T.
Published: April 2023

The recently completed Lindemann Performing Arts Center on the Brown University campus is an exploration in all things flexible. To satisfy the programmatic needs of Brown Arts Initiative, the primary user of this new building, who needed five rooms but only got one, the Main Hall redefined the concept of multiuse hall. All sixsurfaces that define the major acoustically supportive surfaces (ceiling elements, walls, and floors) move to manipulate the otherwise beautifully simple architectural concept into five room configurations—Orchestra, Recital, End Stage Theatre, Experimental Media, and large Flat Floor. A mix of manual and motorized curtains and banners adds still more flexibility. As the paint still dries on the building, this paper will investigate the acoustic challenges, happy accidents, and areas where we might have done with less (or more) in a building that is sometimes heavy handed and sometimes a light touch. The paper will cover topics such as glass as a major reflecting surface, wall buildups that break rules of thumb to produce warm acoustic responses, use of variable acoustic solutions, and ensemble to audience size ratios that challenge conventional wisdom.
Vibration isolation of newer equipment typologies
Authors: Bliefnick Jay , Harlan Mark , Davenny Ben
Published: April 2023

The vibration isolation of large mechanical/electrical/pluming equipment has become an industry standard to prevent unwanted vibrations from transmitting into building structures. ASHRAE, ISO, and other organizations have published recommended guidelines for vibration isolation based on the typical operation of this MEP equipment and “best practices” over the past several decades. However, recent advancements in mechanical equipment designs have resulted in situations where the traditional approach for vibration isolation is either not feasible or ineffective, such as air handling units with extremely well balanced fan arrays or low-speed cooling towers with variable-frequency drives. Changes in power distribution system designs have also resulted in a greater need for vibration isolation of electrical equipment, particularly utility transformers. This paper reviews these recent developments in MEP systems as well as the implications to vibration isolation for this equipment.
Auralization as a value management tool
Authors: Brophy Joshua , Rogers Kelsey , Zaman Khaleela
Published: April 2023

Acoustical consultants tend to rely on written reports, verbal explanations, and drawing markups to convey the scope and meaning of our recommendations. However, since hearing is an inherently perceptive phenomenon, these modes of communication are indirect: they require users and clients to imagine the implications of important design decisions rather than experience them directly. Auralizations can help us fill in those gaps by allowing users to “get a sense” of an acoustical environment before it is built, literally hear how design decisions influence the acoustical outcome, and feel more confident moving forward with the best approach for their project. Most often, these experiences convince decision-makers to devote more resources to the acoustic design than they may have done otherwise, occasionally even going above and beyond the “best practice” recommendation. However, sometimes the simulated outcome of the light touch approach is deemed acceptable to the client, and in these instances, the auralization enables them to avoid the expense of overdesigning. This presentation will explore the spectrum from “client invests more than we expected” to “client reduces costs based on auralization” with a number of case studies related to client decisions that follow the auralization experience.
Monitoring radiofrequency ablation in ex vivo human liver using 3D echo decorrelation imaging augmented by deep learning
Authors: Ghahramani Z. Elmira , Grimm Peter D. , Wang Jiang , Ahmad Syed A. , Shah Shimul A. , Quillin R. Cutler , Patel Sameer H. , Rao Marepalli B. , Mast T. Douglas
Published: April 2023

Monitoring of radiofrequency ablation (RFA) is desirable to improve safety and efficacy of liver tumor treatment. Three-dimensional ultrasound echo decorrelation imaging can successfully predict local ablation effects but has had limited success in mapping ablation zone margins and local tissue temperature. Here, a supervised deep learning approach is investigated to improve prediction of ablation zones and tissue temperature from 3D echo decorrelation images. RFA was performed on ex vivo human liver tissue, including normal, fibrotic, and cirrhotic liver (N > 30). During ablation, pairs of echo volumes were acquired with a 4.5 MHz transesophageal matrix array, 3D echo decorrelation images were computed for each volume pair, and temperatures measured by fourthermocouples integrated into the RFA probe were recorded. Tissue was then frozen, sectioned, scanned, and ablation zones were manually segmented. For prediction of ablation zones, B-mode and echo decorrelation images were input to a U-net convolutional neural network to segment ablation margins, with histology serving as ground truth for training and cross-validation. For prediction of temperature, echo decorrelation values at the thermocouple locations were used as input to train a dense network, minimizing mean-squared-error versus measured temperatures. The results indicate promise for improved mapping of tissue ablation and temperature.
Machine-to-machine transfer function: Transferring deep learning models between ultrasound machines
Authors: Soylu Ufuk , Oelze Michael L.
Published: April 2023

In our previous work, we proposed a calibration method for deep learning (DL) to mitigate the effects of acquisition-related data mismatches in the context of tissue characterization. We showed that the “setting” transfer function can transfer deep learning models between imaging settings. We now extend the calibration method to transfer deep learning models between ultrasound machines. This can lead to reduced cost of model development and also improved understanding of the issues related to the security of deep learning based algorithms in biomedical ultrasound imaging. We gathered four datasets from three different scanners: (i) a SonixOne Machine with an L9-4 transducer, (ii) a Verasonics Vantage 128 Ultrasound Machine with an L9-4 transducer using line by line acquisition, (iii) a Verasonics Vantage 128 Ultrasound Machine with an L9-4 transducer using plane wave compounding, and (iv) a Siemens Antares Ultrasound Machine with an VF10-5 transducer. We used the first dataset as training data and the other datasets as testing data. The DL algorithm learned how to classify two tissue mimicking phantoms. The classification accuracy jumped to 90% from 50% for the second dataset, 70% from 50% for the third dataset, and 61% from 56% for the fourth dataset after incorporating the calibration method. Therefore, the results confirm that a transfer function approach can be used to transfer learning models between scanners for the purpose of classifying materials based on ultrasonic backscatter.
Quantitative ultrasound for preterm birth risk prediction—Part 1: Statistical evaluation
Authors: Mohammadi Mehrdad , McFarlin Barbara L. , Villegas-Downs Michelle , Han Aiguo , Simpson Douglas G. , O'Brien William D.
Published: April 2023

Hypothesis: Predicting the spontaneous preterm birth (sPTB) risk level is enhanced when using both historical clinical (HC) data and quantitative ultrasound (QUS) data compared to using only HC data. HC data defined herein includebirth history prior to that of the current pregnancy as well as, from the current pregnancy, a clinical cervical length assessment, and physical examination data. Study population included 248 full-term births (FTBs) and 26 sPTBs. Advanced statistical analyses were performed for supervised classification containing 53 scaled candidate features (48 QUS, 5 HC) using nested fivefold cross-validation of L1-penalized linear logistic regression with 1000 repetitions to identify potential predictors. Statistical models for HC data alone and HC + QUS data were compared with likelihood-ratio test, cross-validated receiver operating characteristic (ROC) area under the curve (AUC), sensitivity, and specificity. To assess performance, the ROC-AUC was estimated with 10-fold cross-validation logistic regression and 1000 repetitions. Averaged ROC curves plus AUCs were computed using threshold averaging. AUC confidence intervals and test statistics to test the two ROC curves’ differences were constructed via DeLong method. Combined HC and QUS data identified women at sPTB risk with better AUC (0.68; 95% CI, 0.57–0.78) than those of HC data alone (0.53; 95% CI, 0.40–0.66). [Work supported by NIHR01HD089935.]
Quantitative ultrasound for preterm birth risk prediction—Part 2: Clinical consequences and impact
Authors: McFarlin Barbara L. , Mohammadi Mehrdad , Villegas-Downs Michelle , Han Aiguo , Simpson Douglas G. , O'Brien William D.
Published: April 2023

Globally, ∼15 million babies are born preterm every year. In the United States, the preterm birth rate remains stubbornly high (10–15%) and refractory to interventions. Consequences of preterm birth (PTB) account for the second leading cause of infant mortality, with 1 million deaths annually. While the costs of PTB to society are more than for any other disease, the impact on families is devastating. Preterm babies suffer both immediate and lifelong physiological, cognitive, and developmental health problems. It is estimated that with the proper tools and technology, we could reduce the preterm birth and survival rates. Due to lack of technology, clinicians have had few interventions that have been rigorously studied to prevent preterm birth. Ineffective interventions have historically been based on opinion and patient symptoms rather than tissue based reliable and repeatable scientific studies. Our group has rigorously studied quantitative ultrasound’s (QUS’s) role for assessing PTB risk in animals and humans. QUS provided added value to currently available health and traditional ultrasound risk assessment methods. Basing clinical decision-making on tissue microstructure has the potential to reduce the PTB rate and provides a scientific basis for developing and objectively evaluating present and new treatments to prevent PTB. [Work supported by NIHR01HD089935.]
Improved image uniformity using optimized diverging-wave acquisition sequence for high frame rate pulse-echo ultrasound
Authors: Dozier-Muhammad Kashta , Herickhoff Carl
Published: April 2023

Ultrafast pulse-echo ultrasound imaging uses unfocused plane-wave transmit (PWT) or diverging-wave transmit (DWT) wavefronts and coherent compounding for image reconstruction. PWT imaging is more commonly utilizedbut has a limited region of overlapping insonification. This work characterizes the tradeoffs between PWT and DWT, to determine an optimal DWT transmit scheme for given constraints on imaging field of view (depth and width), frame rate, and resolution uniformity. Using Field II, the transmit energy field of a 64-element, 2.75-MHz linear phased array (Verasonics P4-2v) was analyzed for PWT and various active apertures and relative virtual source locations for DWT. This was followed by a Field II calculation and analysis of point-spread functions (PSFs) at many locations in the field (to depth z = 35 mm and x = 20 mm laterally) for each PWT and DWT case, and several cases of PWT and DWT compounding. The amplitude and resolution of the PSF, and the uniformity (variance) of each of these metrics over the field of view, weremeasured in each case. Preliminary results suggest that a DWT scheme provides improved PSF amplitude uniformity over a broader field of view than PWT, with only a slight reduction in lateral resolution at greater depths.
Time evolution of ambient pressure sensitivity of microbubbles subharmonic response as a function of hydrostatic pressure and the filling gas
Authors: Hassanzadeh Azami Roozbeh , Sarkar Kausik
Published: April 2023

The ultrasound contrast microbubbles have shown a great ability to produce nonlinear oscillations in response to acoustic excitation which results in the generation of harmonics and subharmonics of the excitation. The subharmonic response of ½ order changes significantly with a change in hydrostatic pressure in the physiological range. This property is being investigated for subharmonic aided pressure estimation (SHAPE), a noninvasive alternative to current methods for vascular pressure measurement in critical organs. In this study, the ambient pressure sensitivity of the subharmonic response of microbubbles with different gas cores and shells was investigated over 25–700 kPa acoustic pressure and the hydrostatic pressure range of 0–25 kPa. The subharmonic showed different trends of increase and decrease with hydrostatic pressure. The sensitivity has shown gradual change over time which was observed to be related to the hydrostatic pressure magnitude and the gas core. These findings could help to calibrate the SHAPE.
Characterization of lipid shelled microbubbles designed for targeting post-operative nascent abdominal adhesions
Authors: Doheny Victoria V. , McCarthy Colleen M. , Chiu Joanna , Anderson Phillip , Buczek-Thomas Jo Ann , Wong Joyce , Holt R G.
Published: April 2023

Peritoneal adhesions are bands of fibrous tissue that can bind adjacent tissue or organs together and have a high probability of occurrence after a patient undergoes deep abdominal surgery. These adhesions can cause complications, such as chronic pain, intestinal obstruction or constriction, organ displacement, and even death, yet there exists no common diagnostic for these adhesions prior to symptomatic appearance. Furthermore, the gold standard treatment is ironically surgical removal. Nascent adhesions formed in the first 48 hafter surgery are primarily composed of fibrin. In this study, lipid shelled microbubbles have been designed as a potential theranostic agent to detect and treat adhesions using a fibrin targeting peptide called CREKA (Cys-Arg-Glu-Lys-Ala). Low amplitude through-transmission experiments were conducted to characterize the mechanical properties of the microbubble lipid shell, such as the shear modulus of elasticity and shear viscosity. Passive cavitation detection (PCD) experiments were conducted to determine the inertial cavitation threshold by which the microbubbles may break up fibrin under ultrasound exposure. [Work supported by NIH SBIR and BU Mechanical Engineering Department.]