bluuebunny/crossref_metadata_2025 huggingface dataset:
Semantic context influences early speech perception: Evidence from electrophysiology
Authors: Getz Laura , Toscano Joseph C.
Published: April 2019

An unresolved issue in speech perception concerns whether top-down lexical information influences early perceptual representations. This was addressed using the event-related potential (ERP) technique to measure semantic priming effects on the auditory N1, an index of initial acoustic cue encoding. Participants saw visual primes that formed a clear association with the target (Association: “MARCHING band”), led to no specific association (Neutral: “BUTTER bomb”), or consisted of a non-word Mask. Auditory targets were stop consonants varying in voice onset time (VOT) between voiced (/b,d,g/) and voiceless (/p,t,k/) pairs. Participants were faster to identify the initial sound of the target in the Association condition than the Neutral and Mask conditions, and ERP responses showed the expected bottom-up effect of stimulus VOT (larger N1s for shorter VOTs). In Experiment 1, Association primes produced smaller N1s when targets were perfectly predictive, suggesting a top-down attentional effect. In Experiment 2, ambiguous and unexpected VOTs were added, and the results demonstrated that ambiguous VOTs in the Association condition were encoded similarly to the voicing endpoint that matched the semantic context (i.e., larger N1s for voiced expectations). These results provide the first ERP evidence that top-down lexical information directly influences early perceptual responses.
Visual primes, speech intelligibility, and South Asian speech stereotypes
Authors: Vasandani Veera S. , Babel Molly E. , Munson Benjamin
Published: April 2019

Visual primes that suggest social attributes about a talker can affect listeners' speech perception. Recent work by Babel and Russell [J. Acoust. Soc. Am. 137 (2015)] showed that speech intelligibility can decrease when listeners are shown a picture of the speaker when the talker is ethnically Chinese than when the talker is not. They reason that listeners associate Chinese faces with nonnative English accents, which hinders intelligibility. This finding has important implications for our understanding of real-world speech intelligibility when talkers' and listeners' race or ethnicity differ and when these are associated with different language backgrounds. Due to ongoing demographic shifts in the US and Canada, interactions between older and younger adults are often between people with different racial, ethnic, and linguistic backgrounds. This project is a part of a larger research collaboration aimed at understanding the extent and nature of effects of race and ethnicity on speech intelligibility across the lifespan and across levels of hearing acuity. In this talk, we will discuss the results of the first of these experiments, in which we examine speech intelligibility in noise using a large set of talkers whose voices are paired with faces of individuals who are White or South Asian.
Backwards and indirect context effects in accommodating gender differences in speech
Authors: Winn Matthew , Moore Ashley
Published: April 2019

Listeners accommodate large amount of acoustic variability across talkers and phonetic contexts when categorizing speech sounds. This study examines accommodation of gender-related talker differences, which can occur in reverse (in sound sequence AB, sound B affects perception of sound A), suggesting more complicated mechanisms than peripheral auditory contrast enhancement alone. A continuum of fricatives “sh” and “s” was preappended to vowels whose acoustic parameters were manipulated by various properties ranging from typically feminine to masculine and vice versa. Other conditions provided matching or mis-matching visual cues. We examined the weighting of cues to talker gender, the duration of exposure to sound needed to obtain the full context effect, and the influence of hearing status, using listeners with cochlear implants (CIs). CI listeners used different cues to show a comparable gender context effect and also appear to use proxy cues for acoustic properties perceived more clearly by people with normal hearing (NH). All listeners showed implicit knowledge of how acoustic patterns are selectively reverse-compatible with different articulation sequences. NH listeners needed only 30 ms for full adjustment, while CI listeners’ data were much more variable. Collectively, these results show a complex process of auditory, visual and gesture-aware adjustment to a talker’s voice.
Extreme value statistics in flow-induced vibration over long time intervals
Authors: McCluskey Connor , Conlon Stephen , Guers Manton
Published: April 2019

Cyclical loading on structures can lead to fatigue damage, and damage accumulation can be worsened from peak loading. In order to predict these peaks, extreme value statistics can be applied to limited vibration data. Tests must be conducted for long enough durations so that a representative population can be obtained. In extreme value statistics, the Generalized Extreme Value (GEV) distribution’s parameters are also dependent on measuring a representative sample. As it is often uneconomical to test for long periods of time, the proposed experiment aims to look at the behavior of extreme value statistics over long time records to determine if a “minimum requirement” is possible. A cantilever hydrofoil is vibrated under three flow conditions at two angles of attack. Extreme value statistics are applied to compare parameters and distributions for different record length increments. Statistics of each increment are used to generate return plots for the prediction of repeated tests. Errors are quantified to determine the accuracy of the different record lengths. The results will indicate how testing length influences GEV parameters and prediction in vibration, giving insight into duration requirements for future fatigue tests.
An ultrasound study of American English laterals produced by first graders
Authors: Charles Sherman D. , Lulich Steven M.
Published: April 2019

Longitudinal studies of child speech production development have traditionally relied on perceptual evaluation and acoustics to track acquisition norms and phonological patterns. The present study administers novel techniques in speech imaging to investigate the articulation and acoustics of speech sounds in developing children, focusing on the lateral sound /l/ as produced by first graders. Real-time three-dimensional ultrasound images with synchronous audio and video recordings were collected from L1 English speaking children. The stimuli were sourced from the GFTA-3—a clinical picture-naming instrument—which was administered by a speech-language pathology student-clinician. Three-dimensional tongue surface reconstructions and the accompanying audio signals were then compared across tokens and across speakers to find common and divergent patterns for lateral sounds. The results show highly variable articulatory strategies that nevertheless can be categorized into three groups. The wide articulatory variety is not obviously tied to acoustic variability, which is relatively small; formant positions are relatively consistent across tokens and across subjects, with few outliers. From the acoustics alone, these children consistently produce what is traditionally described as the dark /l/, but articulation suggests greater variety.
Interactions among perceived breathiness, roughness, and overall severity of dysphonia
Authors: Eddins David A. , Anand Supraja , Shrivastav Rahul
Published: April 2019

Dysphonic voices typically co-vary across multiple quality dimensions. This study investigates the interaction between breathiness and roughness and their combined contributions to judgments of overall dysphonia severity. Four dysphonic talkers were replicated using a Klatt synthesizer with the Liljencrants-Fant (LF) model as the glottal excitation source. Two vowel continua were created for each speaker by systematically varying aspiration noise (AH) and open quotient (OQ) [to vary the magnitude of breathiness] and the waveform amplitude modulation depth [to alter the magnitude of roughness]. The stimulus matrix for each talker comprises 49 stimuli (7 breathy levels X7 rough levels) resulting in a total of 196 stimuli (4 talkers X49 stimuli).Ten naïve listeners provided judgments of breathiness, roughness, and overall dysphonia severity using a magnitude estimation task. Analyses determined the interaction between talker and listener judgments of breathiness, roughness, and overall severity. A set of iso-severity curves from the ME task were derived and illustrated the combination of breathiness and roughness magnitude to dysphonia severity. These data will be useful in establishing the validity of clinical scales for voice quality perception. [Work supported by NIH DC009029.]
Variations of F2 range measures in mild dysarthria and healthy talkers
Authors: McLaughlin Michaela , Feenaughty Lynda
Published: April 2019

Diminished vocalic segments indexed by the extent, duration, and rate of change in the second formant (F2) are common in dysarthria and are known to reduce intelligibility in adults with multiple sclerosis (MS; Hartelius et al., 2010). When F2 range was measured over select sentences from a reading passage, results indicated that the F2 range may not be sensitive to mild dysarthria in MS (Rosen et al., 2008). However, measures of the F2 range should be further explored for sentences imposing greater speech-motor and cognitive-linguistic demands. As such, phonetic contexts requiring even small vocal tract movement may contribute to intelligibility for speakers with mild dysarthria in MS. Thus, this study will investigate the impact of sentence length and complexity on within-speaker variations of F2 movement and group differences for 12 adults with mild dysarthria in MS and 12 healthy talkers. Various F2 range measures shown to be sensitive to speech motor capabilities will be obtained from 11 audio-recorded sentences varying in length and complexity. The results of this study will provide a better understanding of the speech motor control capabilities of speakers with mild dysarthria with relatively preserved intelligibility in MS. [Work supported by ASH Foundation and the University at Buffalo MDRF.]
Analysis of tongue trajectory variation for /r/ in older children and adults
Authors: Dugan Sarah , Annand Colin , Li Sarah R. , Woeste Hannah M. , Masterson Jack A. , Riley Michael A. , Mast T. Douglas , Boyce Suzanne
Published: April 2019

Kinematic studies of tongue articulator movement have found that older children and adolescents have smaller articulator displacements and greater movement variability compared to adults. However, many of these kinematic studies have used simple, early-developing phonemes as stimuli for comparison across talker groups. The American English rhotic /r/ is the latest to be acquired in children, possibly due to the complexity of the pharyngeal and oral constriction pattern required to produce the sound. In this study, we use automated processing of midsagittal ultrasound images to track trajectories of tongue blade, dorsum, and root during /r/ production in older children and adults. Our preliminary results suggest that the trajectories of tongue parts are different for adults and children, with children producing tongue part movements with greater relative amplitude and variability. We explore the possible developmental reasons for this outcome through the lens of dynamic principles of stability and change.
Secondary acoustic cues in adult perception of young children’s stop productions
Authors: Hitchcock Elaine R. , Koenig Laura L.
Published: April 2019

The perception of plosive voicing distinctions is attributed primarily to voice onset time (VOT). However, perceptual judgments of naturally produced stop tokens may be influenced by secondary cues, such as fundamental frequency (f0) and burst amplitude. The present study assessed the role of secondary cues in adult labeling judgments of bilabial and alveolar CV words produced by 2–3-year-old English-speaking children. Child productions were divided into three groups across the VOT continuum. Four exemplars per phoneme category (/p, b, t, d/) in each range (short, ambiguous, and long) were chosen from 6 children. Two stimulus sets were created. One set included pre-voiced tokens for /b d/ and exaggerated long lag tokens (100+ ms) for /p t/; the other set removed these extreme tokens. Listening data were obtained from adults per set. Listeners were highly accurate (>90%) at labeling the production as intended by the child when the production matched the VOT category expected for the target word. When VOT was ambiguous, judgments for voiced targets ranged from 75% to 92% and voiceless targets ranged from 54% to 62% accuracy. Measures of f0 and burst amplitude suggest that secondary cues in the speech signal contributed to adults’ perception of children's stops.
Physics-based distributions for randomly scattered signals and their Bayesian conjugate priors
Authors: Wilson D. K. , Pettit Chris L. , Ostashev Vladimir E. , Breton Daniel J. , Hart Carl R.
Published: April 2019

Sound waves propagating through the atmosphere and ocean are randomly scattered by turbulence, internal waves, surface roughness, and other processes. In some limiting cases, probability density functions (pdfs) for the scattered signal variations can be derived, e.g., the log-normal pdf for weak scattering (in the Rytov approximation) and the exponential pdf for strong scattering. A variety of more general, usually empirically based, distributions are available which reduce to these limiting cases, such as the Rice, gamma, and generalized gamma. For situations involving multiple receivers, multivariate log-normal, Wishart, and matrix gamma pdfs may be employed. Parametric uncertainties and spatial/temporal variability in the scattering process can be addressed with a compound pdf formulation, which involves an additional distribution for the uncertain or variable parameters. From a Bayesian perspective, the scattering pdf corresponds to the likelihood function, the pdf for the uncertain parameters to the prior/posterior, and the compound pdf to the marginal likelihood. Many common scattering pdfs possess Bayesian conjugate priors, which lend themselves to simple updating equations and analytical solutions for the posteriors and marginal likelihoods. This presentation summarizes important pdfs for randomly scattered signals and their conjugate priors when available.
Bayesian framework for direction of arrival analysis using spherical harmonics
Authors: Weikel Stephen , Landschoot Christopher , Xiang Ning
Published: April 2019

A common task in acoustical applications is the determination of directions of arrival (DoAs) of sound at a receiver. This work aims to address this problem in situations involving potentially multiple simultaneous sound sources by means of a two-level framework of Bayesian inference. This process involves first estimating the number of sound sources present, followed by estimating their directional information, based on sound data collected with a spherical microphone array. Analytical models are formulated using spherical harmonic beamforming techniques, which are incorporated into the Bayesian analysis as part of the prior information. The experimental data are also incorporated to update the information available prior to analysis. All necessary prior information is assigned based on the principle of maximum entropy. Through this technique, the number of sources is first estimated, and then, the DoA information of those sources is extracted from the most concise model that adequately fits the experimental data. This paper presents the Bayesian formulation and analysis results to demonstrate the potential usefulness of model-based Bayesian inference for determining DoAs in complex noise environments with potentially multiple concurrent sources.
Modeling mid-frequency reverberation in the Arctic Ocean
Authors: Tang Dajun
Published: April 2019

With renewed interest in the Arctic in response to its changing environment, various acoustic field measurements are underway or being planned. Anticipating the utility of reverberation as a tool to probe the environment, as well as to detect targets, here a time-domain reverberation model suitable for the frequency band of 0.5—5 kHz is introduced. This model assumes that the sea ice as the scattering mechanism and sea ice scattering parameters are taken from a set of laboratory measurements. It is found that the double-duct sound speed profile in the Arctic enables sound to propagate to long distances, and the main loss mechanism is scattering by sea ice, including ice keels. Reverberation measured at different azimuths is hypothesized as an effective method to estimate angular-dependent keel density and varying sound channels. [Work supported by ONR Ocean Acoustics.]
Characterization of sound channel axis and depth in the global ocean
Authors: Acharya Mukunda , Zhang Likun
Published: April 2019

Sound speed in the ocean has a minimum at a certain depth that acts as the axis of sound channels for underwater sound propagation. In this work, we characterize the three dimensional features of the axial sound speed and depth in the global ocean. The characterization follows from calculation of more than 16 000 sound speed profiles by using the conductivity, temperature, and pressure data in the World Ocean Circulation Experiment. The axial speed and depth as a function of latitude are determined for the Atlantic, Pacific, and Indian oceans, and a polynomial fitting for the dependence is provided. The variability of axial sound channel and depth between different oceans and latitude is identified and related to the feature of the thermoclines of each ocean. The characterization and formulation provide knowledge of the sound channel in the global ocean that could be particularly useful for modeling long-range and three-dimensional underwater sound propagation for applications in underwater acoustic tomography and monitoring seismic activities.
Propagation loss of spawning calls produced by spotted seatrout Cynoscion nebulosus and the effective detection area of passive acoustic sampling
Authors: Biggs Christopher , Wilson Preston S. , Erisman Brad
Published: April 2019

Acoustic signaling in fish has been observed in conjunction with various behaviors but most commonly is associated with spawning. Sound production has been used to identify spawning sites for multiple species, but sound propagation characteristics are often not accounted for, severely limiting the spatial resolution at which spawning sites can be identified. We examined the propagation loss of seatrout calls in the very shallow environment of an estuary using recorded calls and an array of stationary hydrophones. We estimated the minimum expected source level of a seatrout call from the maximum recorded sound pressure level (SPL) of individual fish calls made in situ at spawning sites. Based on preliminary data from 86 samples, the minimum expected source level of an individual call is 142.1 ± 0.9 (CI95) dBrms re: 1 µPa at 1m. Measurements of propagation loss were fitted with a logarithmic model, and preliminary results showed that seatrout calls were detectable above background noise levels between 64 m and 512 m from the source. These results can be used to relate sound levels to the abundance of fish present at a spawning aggregation and enhance the precision of locating spawning sites using passive acoustics.
Multiple f0 pitch estimation for musical applications using dynamic Bayesian networks and learned priors
Authors: Dahlbom David A. , Braasch Jonas
Published: April 2019

The identification of multiple simultaneous pitches is a challenging signal processing task and cannot at present be performed as well as trained human subjects. Moreover, it appears that successful human performance depends on skill acquisition and knowledge of musical conventions. Even human capabilities are likely fairly poor in the absence of training and musical context. We present a framework, using Dynamic Bayesian Networks, that permits the principled incorporation of models of music theory, musical instruments, and human pitch perception. A particular advantage of this approach is the ability to develop each of these models independently, relying either on expert knowledge or machine learning as necessary. Models of appropriate complexity can then be selected for a specific application. In the present work, we focus on the use of learned models of musical context, specifically Deep Markov Models, and use these to improve inferences about simultaneous pitches. The main drawback of this framework is the intractability of the inference computations and the computational expense of approximation methods. We explore particle filtering as an approach to addressing these problems with the ultimate aim of making a system useable in a musical performance system. [Work supported by NSF BCS-1539276 and IBM AIRC grant.]
Impulsive exposures from ceremonial and signal cannons
Authors: Flamme Gregory , Murphy William J. , Kardous Chucri A. , Byrne David C.
Published: April 2019

Cannons, small firearms, and starter pistols are sometimes used with blank charges during sporting events, ceremonies, and historical re-enactments. The sound levels produced by such devices are not widely known, and it is possible that the personnel discharging them could underestimate the potential risk to hearing. Depending upon the proximity to participants and spectators, the sound levels produced by such devices can be potentially hazardous. The exposures have not been widely examined because they fall outside of regulations and standards that cover typical occupational or military exposures. This presentation describes the acoustic characteristics and exposure limits for two large-caliber ceremonial cannons and a signal cannon. The cannons produced impulses between 150 and 174 dB peak sound pressure level (SPL) and 8-h equivalent A-weighted levels ranging between 60 and 108 dBA, respectively. In addition, measurements from small firearms and starter pistols are presented, which produced sound levels between 145 and 165 dB SPL. Such sound levels exceed the various occupational recommended and permissible exposure limits. This paper provides recommendations for noise and administrative controls for all personnel within 15 m of the ceremonial cannons and 10 m of the signal cannon. Double hearing protection should be required during all activities.
Improved automated classification of basketball crowd noise
Authors: Cook Mylan R. , Butler Brooks A. , Pedersen Katrina , Wadsworth Spencer , Todd Eric , Gee Kent L. , Transtrum Mark K. , Warnick Sean
Published: April 2019

This paper describes using both supervised and unsupervised machine learning (ML) methods to improve automatic classification of crowd responses to events at collegiate basketball games. This work builds on recent investigations by the research team where the two ML approaches were treated separately. In one case, crowd response events (cheers, applause, etc.) were manually labeled, and then, a subset of the labeled events were used as a training set for supervised-ML event classification. In the other, (unsupervised) k-means clustering was used to divide a game’s one-twelfth octave spectrogram into six distinct clusters. A comparison of the two approaches shows that the manually labeled crowd responses are grouped into only one or two of the six unsupervised clusters. This paper describes how the supervised ML labels guide improvements to the k-means clustering analysis, such as determining which additional audio features are required as inputs and how both approaches can be used in tandem to improve automated classification of crowd noise at basketball games.
Numerical modeling of submicron particle acoustic concentration in gaseous flow
Authors: Liu Jizhou , Li Xiaodong , Hu Fang Q.
Published: April 2019

The acoustic concentration of submicron particles in a micro-channel is investigated numerically via a gas-particle multiphase coupling scheme. For modeling the gas flow under transverse standing wave, 2 dimensional linearized Euler equations with the parabolic mean flow are employed with the high order finite difference method. Through the analogous behavior of rarefied gas and air-suspended particles, a modified Unified Gas-Kinetic Scheme (UGKS) is adopted to estimate the particle dynamics. In detail, Stokes' drag force and acoustic radiation force applied on particles are accounted for by introducing a velocity-dependent kinetic acceleration term in the UGKS. To validate this modeling, numerical simulations are tested with varying standing wave amplitudes. The effects of acoustic radiation force to drag force ratio and mean flow velocity are also analyzed. The computed concentration patterns and efficiencies are compared with experimental results from the literature. The agreement shows that the adopted Euler-UGKS coupling scheme could be an effective tool for micro-sized particle acoustic concentration applications.
Development of heavy metal ions detector driven by surface acoustic waves
Authors: Liu Yue , Wang Chaohui , Zheng TengFei
Published: April 2019

Environmental pollution caused by heavy metals is a global problem. Most of the metal ions lead to serious health concerns by producing free radicals. Therefore, rapid and accurate detection of metal ions has become an urgent problem. We develop a highly sensitive detector to detect heavy metal ions driven by surface acoustic waves (SAWs). The detector consists of a micro-reaction cell, a three-electrode system for electrochemical measurements, and two focused interdigital transducers (FIDTs) that produce SAWs. The SAWs promote liquid mixing effectively by sufficiently stirring the aqueous solution; therefore, the oxidation current in electrochemical reactions is enhanced. Furthermore, the center angles of the FIDT and the distance between two FIDTs turn out to be critical parameters in reaction efficiencies. These two factors can affect the SAW radiation areas which can influence the reaction efficiencies. This study realizes rapidly and accurately detecting heavy metal ions and provide a basis for designing SAWs-based detector for different chemical reactions.
Standing surface acoustic waves controlling crystal shapes: The case of urea
Authors: Zheng TengFei , Liu Yue , Wang Chaohui
Published: April 2019

It is important to control crystal shapes, for this is particularly significant in nano-technology and in medicine. In this paper, we use standing surface acoustic waves (SSAWs) based technique to control the urea crystal shapes in a microdroplet. The surface acoustic waves are excited by a sinusoidal electric potential applied to inter-digital transducers on the surface of a X-propagating lithium niobate (LN) single-crystal piezoelectric substrate. A microdroplet is placed on the waves propagation path. SSAWs radiate into the droplet and influence the crystallization process when the droplet evaporates. First, we investigated the effect of acoustic intensity. Second, we controlled the shape of the crystal by changing the wave frequency. Finally, we controlled the shape of the crystal by changing the LN surface properties. Moreover, the streaming induced by SSAWs was observed by particle image velocimetry. Moreover, it is easier to control the wave frequency, acoustic intensity, and the surface properties than to control acoustic cavitation. This research will promote the application of SSAWs in controlling crystal forms.
Sentence perception in noise by hearing-aid users: Relations with syllable-constituent perception and the use of context
Authors: Miller James D. , Watson Charles S. , Leek Marjorie R. , Wark David J. , Souza Pamela , Gordon-Salant Sandra , Ahlstrom Jayne B. , Dubno Judy R.
Published: April 2019

Masked sentence perception by hearing-aid users is strongly correlated with three variables: (1) the ability to hear phonetic details as estimated by the identification of syllable constituents in quiet or in noise; (2) the ability to use situational context that is extrinsic to the speech signal; and (3) the ability to use inherent context provided by the speech signal itself. These conclusions are supported by the performance of 57 hearing-aid users in the identification of 109 syllable constituents presented in a background of 12-talker babble and the identification of words in naturally spoken sentences presented in the same babble. A mathematical model is offered that allows calculation of an individual listener's sentence scores from estimates of context utilization and the ability to identify syllable constituents. When the identification accuracy of syllable constituents is greater than about 55%, individual differences in context utilization play a minor role in determining the sentence scores. As syllable constituent scores fall below 55%, individual differences in context utilization play an increasingly greater role in determining sentence scores. When a listener's syllable constituent score is above about 71% in quiet, the listeners score in quiet will above about 55% in noise. [Watson and Miller are shareholders in Communication Disorders Technology, Inc., and may profit from sales of the software used in this study.]
Earlier music biases subsequent musical instrument categorization
Authors: Lanning Joshua M. , Stilp Christian
Published: April 2019

Perception of sounds occurs in the context of surrounding sounds. When spectral properties differ between earlier (context) and later (target) sounds, categorization of later sounds becomes biased through spectral contrast effects (SCEs). Past research has shown SCEs to bias categorization of speech and music alike. Additionally, the magnitudes of SCEs are not all-or-none but vary continuously in both speech and music categorization. Recently, the natural spectral composition of (unfiltered) sentences biased speech categorization via SCEs (Stilp and Assgari, under review). Here, we tested whether natural (unfiltered) music would similarly bias categorization of French horn and tenor saxophone targets. Preceding contexts were either solo performances of the French horn or tenor saxophone (unfiltered) or a string quintet processed to emphasize frequencies in the horn or saxophone (filtered). Categorization was influenced by SCEs in both unfiltered and filtered conditions, with more “saxophone” responses following horn / horn-like contexts and vice versa. Since unfiltered music produced SCEs in musical instrument categorization, this extends their influence to everyday listening conditions.
Design optimization of three styles of acoustic black hole vibration absorbers
Authors: McCormick Cameron A. , Shepherd Micah R.
Published: April 2019

Structures whose thickness is tapered according to a power law exhibit the acoustic black hole (ABH) effect and can provide effective vibration absorption with a net reduction in mass. However, it remains unclear what constitutes the best design of ABH vibration absorbers, including how the power-law taper is implemented in practice. This talk will present a formal optimization study of three styles of one-dimensional ABH vibration absorbers. Each ABH is embedded in a simply supported beam, which is excited by a harmonic force at one end. A multi-objective approach is used to identify the set of ABH designs that optimally minimize the structure’s vibration response and its overall mass. Results show that each style has a similar tradeoff between the two objectives but that the choice of how the power-law taper is implemented can be significant. Finally, the optimal designs will be evaluated on other criteria that may be of importance in the practical implementation of such ABH vibration absorbers, including buckling load and sound radiation.
Pitch range, intensity, and vocal fry in non-native and native English focus intonation
Authors: Hong-lun Yeung Alex , Baek Hyunah , Takahashi Chikako , Duncan Joseph , Benedett Sharon , Hwang Jiwon , Broselow Ellen
Published: April 2019

23 native English speakers (ES) and 25 native Mandarin speakers (MS) participated in a study of the production of contrastive focus prosody in English. The participants completed an interactive game in which they directed experimenters to decorate objects, producing sentences containing contrasting noun phrases in which either the adjective or noun was contrasted (e.g., Andy wants an orange diamond on his towel and a NAVY diamond/orange OVAL on Mindy’s towel). Time-normalized average pitch and intensity contours extracted from a subset of the speakers suggest that while both groups distinguish adjective from noun focus, the MSs show a wider pitch range but smaller intensity drop than the ESs, consistent with a previously reported study of contrastive focus production (Takahashi et al., 2017). A surprising pattern in the data was that the MSs actually showed a stronger use of pitch cues on the focused noun than the ESs, which may have reflected the fact that many of the ESs exhibited creakiness toward the end of the sentence, restricting their use of pitch to mark focus on nouns. We argue that these divergent patterns reflect a combination of Mandarin L1 influence and innovative vocal fry prosody in native English speakers.
Non-native perception and first language experience: The case of English final stop perception by Saudi Arabic listeners
Authors: Alamri Sarah
Published: April 2019

This study investigated how listeners' native language [Saudi Arabic (SA)] could affect the perception of non-native (English) sound patterns. SA stopsare generally released, while English stops show free variation: released or unreleased. In a phoneme detection task, SA listeners were asked to detect English stops in coda position, and their accuracy and reaction time (RT) were measured. The influence of three factors of the final coda (i.e., release, voicing, and place of articulation) on the accuracy and RT was statistically analyzed using mixed effect models. The results indicated a significant interaction among the three factors on the listeners' accuracy but not on the RT. The results revealed that listeners relied mostly on release bursts as a phonetic cue to accurately detect the target phoneme. The significant interaction between release and voicing suggested that the unreleased voiced stops were easier to detect than the voiceless counterparts. Despite the difference in the accuracy, the listeners' RT was not significantly influenced by release, voicing, or place of articulation. The results suggested that L1 experience effects non-native perception if the target phoneme does not have enough acoustic information. Listeners can accurately detect unfamiliar sound patterns when the signal is acoustically rich.
Acoustic analysis of nasal and lateral consonants: The merger in Eastern Min
Authors: Cheng Ruoqian , Jongman Allard
Published: April 2019

The contrast between word-initial [n] and [l] is disappearing in many Chinese languages, including Eastern Min. Before investigating the status of the merger, we need to identify the acoustic cues that distinguish [n] from [l]. In English and Mandarin, languages with the [n] and [l] contrast, we examined: (1) Duration: consonant duration and consonant-vowel transition duration; (2) Formant frequencies: F1, F2 and F3 at the midpoint of the consonant; (3) Formant intensities: I1, I2, and I3 at the midpoint of the consonant; and (4) Relative amplitude (the amplitude difference between the consonant and the following vowel). Preliminary results show that [n] is significantly longer than [l] in Mandarin and English but not in Eastern Min. F2 of [n] is higher than F2 of [l] in English and Mandarin, whereas the direction is reversed in Eastern Min. Finally, the difference in relative amplitude between [n] and [l] is greater in English and Mandarin than in Eastern Min. Together, these results suggest a merger in progress in Eastern Min . Moreover, older Eastern Min speakers showed the merger to a greater degree than younger speakers, presumably because the older speakers use Mandarin less frequently.
Distinguished Service Citation 2019: David Feit
Authors: Feit David
Published: April 2019

The Distinguished Service Citation is awarded to a present or former member of the Society in recognition of outstanding service to the Society.
Use and misuse of auralization
Authors: Ahnert Wolfgang
Published: April 2019

Auralization was developed as a tool in the 30s. The historic overview over this development starts by using scale models as a design tool which is used until now. Here, the needed components are explained, and the pros and cons will be discussed. With the use of computer simulation in the end of the 60s, the presentation of auralized files started around 1990 first considered as a toy. Today the use of auralization is widespread. This paper describes the development of the technical tools to present auralized signals available for binaural reproduction without and with head tracker and by using loudspeaker reproduction without and with crosstalk cancelation. Nowadays, Acoustic labs with Ambisonics reproduction or similar technologies are used. In this presentation, the advantages of auralization are named including all positive properties to demonstrate the achieved simulation results to different client groups. But also, the misuse of auralization is shown in detail by using found examples.
An analysis of ceiling geometry within active learning classrooms
Authors: Skorski Edwin S.
Published: April 2019

The architectural designs and furnishing of active learning classroom spaces are playing an increasingly important role in the facilitation of modern educational methods. Traditional static classroom spaces effectively support a lecture style of teaching where student participation is passive. Due to their rigid space plan, they are poor at encouraging interaction among students and teachers. Conversely, active learning spaces promote innovative teaching methods where quick room re-configuration allows for discussion groups of various sizes, the simultaneous use of a variety of teaching methods, and provides greater opportunity for the incorporation of technology into the classroom. From a room acoustic perspective, the increase in room arrangement flexibility leads to a complex acoustic environment where the spatial relationship between the source and the receiver is highly variable. This study uses digital modeling and computer simulation to analyze the effects of the ceiling geometry as it relates to the active learning classroom acoustic environment. Specifically, the study focuses on changes in speech intelligibility and reverberation time as the overhead plane is manipulated.
Design of a multiple-slope sound energy decay system with string and block coupling methods
Authors: Du Xuhao , Pan Jie , Guzzomi Andrew
Published: April 2019

Driven by the need of both speech intelligibility and music perception, multiple-slope sound decay in a room has been studied for decades. To step further, two different room coupling methods are proposed for achieving decay with quadruple, quintuple, or higher slope numbers. Starting from a triple-slope sound decay system, the understanding of energy flow in such a system is developed as well as the relationship between the decay turning points and the aperture size. Each decay slope represents the acoustic characteristic of the corresponding dominating room, and the dominating durations are determined by the couple condition. Based on the understanding of its energy flow, two different coupling methods, the string coupling and block coupling, are developed for achieving specific non-exponential sound decay with the specific number of slopes, slope values, and times of turning point. These are controlled by parameters including the room quantity, the reverberation of each room, and the coupling aperture sizes. Based on the above coupling methods, a few examples are simulated with the diffusion equation for verifying the energy flux and achieving a specific multiple-slope sound energy decay pattern inside the room.
Full wave 3D inverse scattering: 21st century technology for whole body imaging
Authors: Wiskin James , Malik Bilal , Natesan Rajni , Pirshafiey Nasser , Lenox Mark , Klock John
Published: April 2019

Quantitative high resolution (QHR) images of speed of sound and attenuation in human breast have been made using full wave inverse scattering in three-dimension (FWIS3D), where only soft tissue is present. The FWIS3D technology and method are reviewed. Recent QHR images in the presence of bone and gas have been obtained with FWIS3D and are shown. Transmission mode quantitative and refraction corrected reflection images of small piglet abdomen, thorax, and head are shown. QHR images of the human knee using the same technology are shown. Human Knee is difficult due to the predominant presence of bone. With low frequency FWIS3D, the meniscus, structure within the Femur-Tibia (F-T) space, ligaments, and the infrapatellar fat pad can be seen. The intra-condyle space in the Femur is visible. It was earlier established that 3D modelling was necessary for breast. It is shown to be even more important for F-T space and whole body imaging. Quantitative estimates of high speed early development bone are made, and imaging through neo-natal skull is performed. Clear correspondence with known structures even in the presence of gas is displayed. This reveals FWIS3D ultrasound tomography as a 21st century whole body imaging modality.
Iterative image reconstruction algorithm for transcranial photoacoustic tomography applications
Authors: Poudel Joemini , Wang Lihong , Anastasio Mark
Published: April 2019

Photoacoustic computed tomography (PACT) is an emerging computed imaging modality that exploits optical contrast and ultrasonic detection principles to form images of the absorbed optical energy density. The PACT reconstruction problem corresponds to recovering the total absorbed optical density within a tissue sample, from the acoustic waves recorded on a measurement aperture located outside the support of the tissue sample. A major challenge in transcranial PACT brain imaging is to compensate for aberrations in the measured photoacoustic data due to their propagation through the skull. To properly account for these effects, a wave equation-based iterative reconstruction algorithm that can model the heterogeneous elastic properties of the medium is employed. To accurately recover the absorbed optical energy density, complete knowledge of the spatial distribution of the elastic parameters of the medium is required. However, estimating the elastic properties of the medium prior to the experiment is practically infeasible. To circumvent this, we propose to jointly reconstruct the absorbed optical energy density and the spatial distribution of the elastic parameters of the medium from PACT data alone. Reconstructed images from both numerical phantoms and experimental data are employed to demonstrate the feasibility and effectiveness of the approach.
Comparison of elastic modulus inverse estimation and the pulse wave velocity estimation for monitoring abdominal aortic aneurysms
Authors: Mix Doran , Cybulski Luke , Stoner Michael , Richards Michael S.
Published: April 2019

The necessity of surgical intervention of abdominal aorta aneurysms is based on a risk-reduction paradigm primarily relying on trans-abdominal ultrasound (US) measurements of the maximum diameter of an AAA. However, the AAA diameter is only a rough estimate of rupture potential, and elastographic estimates of material property changes within aortic tissue may be a better predictor. This work compares an elastic imaging technique measuring aortic tissue stiffness in cross-section to a pulse wave velocity (PWV) estimate obtained from longitudinal images of the same geometry using a two-dimensional clinical US machine. The elastic imaging technique uses a linear elastic finite-element model to solve the elastic inverse problem and estimates the shear modulus. This technique uses a non-invasive pressure cuff to estimate the pressure in the aorta and normalizes the modulus values. The PWV technique uses geometric measurements and simplifies assumptions to create a direct relation between the wave speed and the modulus. Results of validation studies using aortic mimicking phantoms comparing modulus obtained from each of the techniques are presented. Initial clinical results will be also be presented.
Inferring elastic moduli of drops in acoustic fields
Authors: Batson Jesse , Davis Rebekah , Holt R. Glynn
Published: April 2019

Acoustically levitated drops serve as non-contact mini-laboratories from which one can infer material properties from the response of the drop to the acoustic radiation force. Oddly enough, the oscillatory problem is more well-developed than the static problem. Analysis of the static acoustic deformation of Newtonian liquid drops is well established, yielding the inference of the surface tension. But the static deformation of an elastic drop is less well studied. The present work aims to enable the inference of elastic moduli from static deformations of acoustically levitated drops. The drop will be modeled as an incompressible, linear elastic solid undergoing small axisymmetric deformations. The axisymmetric interior stress and displacement fields will be found using Love's strain potential. The traction boundary condition can be calculated using linear acoustic theory . The measured static deformation of experimentally levitated drops with known material properties (polymer and protein gels) will be compared to the predictions of the theory. Time permitting, a finite element computational model will also be employed for comparison.
Approximate analytical time-domain Green’s functions for space-fractional wave equations
Authors: McGough Robert , Kelly James F. , Carriere Madison
Published: April 2019

Approximate and exact time-domain Green’s functions are available for time-fractional wave equations that describe power law attenuation in soft tissue, where each expression contains a stable probability distribution function. Previous work has also demonstrated that the exact time-domain Green’s functions for time-fractional and space-fractional wave equations that describe power law attenuation are similar. Approximate analytical time-domain Green’s functions have recently been derived for the Chen-Holm and Treeby-Cox space-fractional wave equations, where the approximate time-domain Green’s function for the Chen-Holm wave equation contains a symmetric stable probability distribution function and the approximate time-domain Green’s function for the Treeby-Cox wave equation contains a maximally skewed stable probability distribution function. Comparisons between the exact numerical and approximate analytical expressions for these time-domain Green’s functions are evaluated for published values of the power law exponent and attenuation constant for breast and for liver. The results for both breast and liver converge very close to the source, and similar performance is observed in time-domain Green’s functions computed for linear with frequency attenuation. Despite minor differences in the arguments, the approximate analytical time-domain Green’s functions derived for dispersive time-fractional and space-fractional wave equations are also quite similar. [Work supported in part by NIH Grants EB023051 and EB012079.]