bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling and numerical simulation of the bubble cloud dynamics in an ultrasound field for burst wave lithotripsy
Authors: Maeda Kazuki , Colonius Tim , Maxwell Adam D. , Kreider Wayne , Bailey Michael R.
Published: October 2018

Modeling and numerical simulation of bubble clouds induced by intense ultrasound waves are conducted to quantify the effect of cloud cavitation on burst wave lithotripsy, a proposed non-invasive alternative to shock wave lithotripsy that uses pulses of ultrasound with an amplitude of O(1) MPa and a frequency of O(100) kHz. A unidirectional acoustic source model and an Eulerian-Lagrangian method are developed for simulation of ultrasound generation from a multi-element array transducer and cavitation bubbles, respectively. Parametric simulations of the spherical bubble cloud dynamics reveal a new scaling parameter that dictates both the structure of the bubble cloud and the amplitude of the far-field, bubble-scattered acoustics. The simulation further shows that a thin layer of bubble clouds nucleated near a kidney stone model can shield up to 90% of the incoming wave energy, indicating a potential loss of efficacy during the treatment due to cavitation. Strong correlations are identified between the far-field, bubble-scattered acoustics and the magnitude of the shielding, which could be used for ultrasound monitoring of cavitation during treatments. The simulations are validated by companion experiments in vitro. [The work was supported by NIH P01-DK043881 and K01-DK104854.]
Design of a transducer for fragmenting large kidney stones using burst wave lithotripsy
Authors: Randad Akshay P. , Ghanem Mohamed A. , Bailey Michael R. , Maxwell Adam D.
Published: October 2018

Burst wave lithotripsy (BWL) is a potential noninvasive treatment for breaking kidney stones. BWL requirements of high-pressure output, limited aperture for acoustic window, and specific focal length and frequency constrain the focal beam width. However, BWL is most effective only on stones smaller than the beam width. We tested a porous piezoelectric material (PZ36) to increase the output power and designed acoustic lenses that broaden the beam. A weighted iterative angular spectrum approach was used to calculate the source phase distribution needed to generate desired cross sectional focal beam profiles each of 12 mm width. The phase calculations were then 3D printed as holographic lenses placed over a circular aperture of 80-mm diameter, 350 kHz PZ36 to produce the desired beam at 85 mm depth. The difference in simulated beam width and that measured by hydrophone was <1 mm, and the structural-similarity index value was greater than 0.65. The differences in structures were due not to shape and size of the 6-dB contours but to amplitude distribution within the contour. In conclusion, this design approach combined with 3D printing provide a way to tailor focal beam profiles for lithotripsy transducers. [The work was supported by NIDDK P01-DK043881 and K01-DK104854.]
Acoustic bubble coalescence and dispersion for enhanced shockwave lithotripsy
Authors: Alavi Tamaddoni Hedieh , Hall Timothy L.
Published: October 2018

The goal of this study is to develop methods to improve shockwave lithotripsy (SWL). Although cavitation on the surface of a stone may aid fragmentation, cavitation away from the stone may block subsequent shockwaves or cause tissue damage. In previous work, we have shown low amplitude acoustic bursts immediately after each shockwave can force cavitation bubbles to coalesce enhancing SWL efficacy. In this study we examined the feasibility of acoustically dispersing bubbles away from the propagation path immediately before the arrival of the next shockwave. A clinical Dornier lithotripter was used with an in-house made transducer to generate Acoustic Bubble Coalescence and Dispersion (ABCD) pulses fired at different timing with respect to each shockwave. Model stones were treated with 2500 shockwaves at 30 shocks/min or 120 shocks/min and four different ABCD pulse sequences in-vitro. Results showed fragments larger than 2 mm were significantly reduced for all four ABCD sequences cases at 120 shocks/min. The remnant mass of fragments larger than 2 mm was 0.16% at low rate of 30 shocks/min, and 15.81% at 120 shocks/min without ABCD, and 0.19% at 120 shocks/min with ABCD. These results suggest that dispersing residual bubbles can aid in fragmentation efficiency allowing faster SWL treatments.
Confocal lens focused piezoelectric lithotripter
Authors: Thomas Gilles , Chapelon Jean-Yves , Birer Alain , Lafon Cyril
Published: October 2018

Usually, piezoelectric lithotripters consist of a high quantity of small flat piezoelectric discs tied to a spherical structure, where the focus is the geometric center of the sphere. The small diameter of the ceramics compared to the distance to the focus of the lithotripter means that only a fraction of the surface pressure will arrive to the focus, and also results in a very small focal diameter. This work focus on the evaluation of a new type of piezoelectric lithotripter with similar dimensions of a commercial lithotripter and composed of either 3 or 4 large lens focused piezoelectric transducers with focal pressure up to 25 MPa each, set either in a confocal C-shape or confocal ring-shape. Each transducer is made with a 92 mm diameter flat piezoelectric ceramic disc of 220, 300, or 400 kHz thickness frequency and the acoustic lens shape was calculated using finite element optimization in order to maximize its focusing capability. Comparison of artificial stone comminution efficiency depending on the frequency, pressure, and the setup of the piezoelectric transducers were made and compared to commercially available lithotripters. [Work supported by an industrial grant from EDAP-TMS.]
Experimental assessment of guided waves far-field scattering around damage in metallic and composite structures
Authors: Masson Patrice , Quaegebeur Nicolas , Sherafat Mohammad H. , Lessard Larry , Hubert Pascal
Published: October 2018

Experimental damage simulation is useful for designing ultrasonic guided-wave based systems for non-destructive evaluation (NDE) and structural health monitoring (SHM). However, simulating the scattering of guided waves with geometrical (rivets, thickness changes, stiffeners, and extrusions) or damage features (fatigue cracks, fillet cracks, delaminations, and disbonds) remains a challenge. The objective of this work is to assess to which extent the interaction of ultrasonic guided waves with typical damage can be captured with an experimental model for a metallic structure and a composite structure. For the metallic structure, real fatigue cracks around a rivet hole are simulated by machined notches, while, for the composite structure, the impact damage is simulated by a single artificial delamination introduced into the laminate using two circular Teflon tapes during manufacturing. This paper implements an experimental methodology for estimating the far-field scattering for both simulated and real damage. Two co-localized rectangular piezoceramics are used to generate the guided waves and non-contact measurement is performed using a three-dimensional laser Doppler vibrometer (3D-LDV) to extract the required information for evaluation of the reflection, transmission, as well as the scattering behavior of the waves. The corresponding coefficients as a function of frequency, incident angle, and type of damage are extracted.
In vitro and in vivo comparison between methods based on quantitative ultrasound and on resonance frequency analysis to assess dental implant stability
Authors: Vayron Romain , Nguyen Vu-Hieu , Haiat Guillaume
Published: October 2018

Resonance frequency analyses (RFA) and quantitative ultrasound (QUS) methods have been suggested to dental assess implant stability. The aim of this study was to compare the results obtained using these two techniques in vitro and in vivo. Implants were inserted in bone phantoms with different values of density and cortical thickness to assess the effect of bone quality on the ultrasonic indicator (UI) and on the ISQ values. 81 identical implants were inserted in the iliac crests of 11 sheep. The QUS and RFA measurements were realized after different healing times. ISQ values increase and UI values decrease when i) the bone density and ii) cortical thickness increase. The error realized on the estimation of the trabecular density (respectively cortical thickness) with the QUS device is around 4 (respectively, 8) times lower compared to that made with the RFA technique. The error made on the estimation of the healing time using the QUS technique was 10 times lower than using the RFA technique. The results show that ultrasound technique provides a better estimation of different parameters related to the implant stability compared to the RFA technique, paving the way towards the development of a decision support system to dental surgeons.
Phase velocity dispersion estimation of viscoelastic materials by two-point wavelet-based method
Authors: Kijanka Piotr , Ambrozinski Lukasz , Urban Matthew W.
Published: October 2018

Ultrasound shear wave elastography (SWE) is a promising imaging modality used for noninvasive, quantitative evaluation of tissue mechanical properties. This method uses an acoustic radiation force to produce laterally propagating shear waves that can be tracked to obtain the wave velocity. One of the ways to explore the viscoelasticity is through examining the shear wave velocity dispersion curves. In this paper, we present an alternative method to the classical two-dimensional Fourier transform (2D-FT), a two-point wavelet transformation method. We use the Morlet wavelet function as the mother wavelet to filter two shear waves at different locations. We examined how starting distance from the push and distance between the two locations affected the shear wave velocity dispersion. We tested this method on digital phantom data created using local interaction simulation approach (LISA) in viscoelastic media and on data acquired from phantom experiments. We compared results from the two-point method with the 2D-FT technique. The two-point method provided dispersion curves estimation with lower errors over a wider frequency band. Tests conducted showed that the two-point technique gives results with better accuracy in simulation results and can be used to measure phase velocity of viscoelastic materials.
A new pre/post test to assess student mastery of introductory level acoustics and wave mechanics
Authors: Piacsek Andrew A.
Published: October 2018

The Force Concept Inventory is a widely used multiple-choice test that enables physics educators to assess the ability of students to apply basic concepts associated with Newton’s laws and to identify specific misconceptions held by students. When administered at the beginning of a course in introductory physics, as well as at the end, the FCI provides a reliable measure of the gain in student understanding. The usefulness of the FCI, and its ease of use, has spurred the development of similar “inventories” and “baseline tests” for other subjects in the physical sciences, such as the Fluid Mechanics Concept Inventory, the Conceptual Survey in Electricity and Magnetism, and the Thermodynamics Concept Inventory. This presentation will describe a new concept inventory test designed to assess students’ conceptual understanding of the behavior of oscillators and mechanical waves, their understanding of the measurement and perception of sound, and their ability to interpret graphical representations of sound. Following the FCI model, this new Sound and Vibration Concept Inventory forces students to compare correct answers to those based on common misconceptions. Preliminary efforts to assess the reliability of this test will be described.
Using and assessing mechanical wave tutorials in introductory physics
Authors: Dostal Jack
Published: October 2018

The Tutorials in Introductory Physics curriculum produced by the University of Washington Physics Education Group includes tutorials on mechanical waves. The tutorials are written in the style of a Socratic dialogue on topics like superposition, reflection, and transmission of waves. These tutorials have a physics education research basis, leading the student to address common difficulties and misconceptions that have been broadly demonstrated by other students. The tutorials also come with homework assessments and pretest/posttest questions. I will describe my use of these and other tutorials in my own classes, both in standard calculus-based introductory physics courses, as well as in a non-major physics of music class.
Measuring educational outcomes for ABET accreditation of the undergraduate acoustical engineering programs at the University of Hartford
Authors: King Eoin A. , Celmer Robert
Published: October 2018

Located in West Hartford, CT, USA, the University of Hartford has two ABET-accredited acoustical engineering programs: the Bachelor of Science in Mechanical Engineering (BSME) with Acoustics Concentration and a unique interdisciplinary Bachelor of Science in Engineering with a major in Acoustical Engineering & Music. The national Accreditation Board for Engineering & Technology accreditation process requires that an institution identify and provide evidence of Program Educational Objectives, Student Outcomes, Required Curricular Components, Relevant Facilities, Faculty Expertise, and Methods of Continuous Improvement. The differences and key points of these criteria will be discussed, along the manner by which each are measured. The results of a recent ABET accreditation visit will be described.
Imperatives of acoustics and musical instrument acoustics education to the Nigerian educational system in tertiary institutions
Authors: Onwubiko Stephen G. , .Adeogun Adebowale O. , Nnabuchi Joy O. , Kemewerigha Tobi E. , Onwubiko Ikechukwu E.
Published: October 2018

This paper discusses about the imperatives of acoustics and musical instrument acoustics education to the Nigerian educational system. It identifies the prospects, the long term educational effects, problems and proffered possible solutions to them. In achieving its objectives the study uses ethnographic and qualitative methods with simple percentages for eliciting and collation of data. The paper suggests that the Acoustics societies work with our curriculum planners, and the government to implant acoustics and its education to tertiary institution in Nigeria. The research questions raised guided the study. It proposes as part of its recommendations that other acoustical bodies provide necessary facilities and personnel for acoustics and its education to thrive as a core subject or vocational subject; and that the larger society must become educated on the usefulness of acoustics as a career subject worth pursuing by scholars.
Fitness centers in mixed-use development: Examples from practice
Authors: Markham Benjamin , Brush Ethan , Connick Robert
Published: October 2018

Spin classes utilize sound systems that generate levels in excess of 115 dBA, with subwoofers to match. Gyms located in office buildings feature Olympics style weight lifting technique that involves dropping 200 lb (or more) barbells from shoulder or overhead positions. Medicine balls get thrown at walls and floors. More “typical” sources of airborne and structureborne noise—treadmills, aerobics classes, weight machines, and the like—contribute to the din. The authors will present experiences and lessons learned from actual field experience with fitness centers located in commercial, residential, and mixed-use developments. Data will be presented on the effectiveness of mitigation methods installed in real buildings to attenuate airborne and structureborne noise. The session will include a discussion of the various types of fitness franchises and associated acoustic concerns, illustrated by case study examples from the authors’ acoustical consulting experience.
Assessment and remediation of treadmill generated vibration increased due to a building modification
Authors: Phillips James E.
Published: October 2018

Structural modifications to an existing multi-story building installed to increase the load bearing capacity of a floor resulted in a noticeable increase in floor vibration from treadmills used in a fitness room on the floor above. Results from vibration measurements were combined with a finite element analysis (FEA) model of the building dynamics to determine the dynamic force generated by the treadmills in use. The FEA model and the calculated dynamic force were used to evaluate the effectiveness of options for vibration isolating the treadmills to reduce vibration to acceptable levels in the occupied office below.
Effects of noise exposure on hearing health evaluated through short interval otoacoustic emission monitoring: Preliminary results with low and moderate noise exposure groups
Authors: Nadon Vincent , Voix Jeremie
Published: October 2018

Industrial workers are often exposed on a daily basis to noise doses that put them at risk of Noise-Induced Hearing Loss (NIHL), which remains the largest cause of indemnity in North America industries. To improve occupational hearing loss prevention programs, a method to continuously measure hearing fatigue using otoacoustic emissions (OAE) has already been proposed by the authors using a portable and robust OAE system designed for noisy industrial use. The effectiveness in the field of the aforementioned method is examined by comparing a control group of unexposed subjects in laboratory and noise exposed subjects in the field. All participants are equipped with an hearing protection earpiece which includes the usual OAE measurement components as well as a microphone mounted on the outer faceplate of the earpiece. At regular intervals over the course of the day, the growth function of distortion product OAEs is measured for both groups while simultaneously measuring noise levels inside and outside the ear. Medial olivocochlear reflexes are also measured pre and post exposure to monitor other potential effects on hearing. Preliminary results of this study are presented and analyzed in the broader context of the dose-response relationship that could indicate individuals’ risk to develop NIHL.
Improving the speed of acoustic propagation modeling, for sonar training applications, with a 3D Gaussian ray bundling model
Authors: Reilly Sean M. , Potty Gopu R.
Published: October 2018

This research improves the calculation speed of acoustic propagation modeling, for sonar training applications in littoral environments, by implementing a 3D Gaussian ray bundling model in the geodetic coordinates of the environmental databases. Tactical decision aids currently transform the three-dimensional environment into two dimensional radials, then compute acoustic propagation as a function of range and depth. This allows them to analyze millions of range, depth, and bearings for potential targets locations in a few minutes. But, it assumes that the cost of transformation is small compared to the speed benefit of computing propagation in Cartesian coordinates. This assumption is violated in applications where the geometry of the sensors and targets is rapidly evolving, results are strongly dependent on location, and answers must be produced faster than real time. Instead of relying on advancements in computer hardware, this research focuses on the development of a new algorithm to compute bistatic, broadband, transmission loss, and reverberation for 100 active sonar acoustic contacts on commodity laptop hardware, at rates ten times faster than the speed of sound, with no measurable impact on accuracy. [Work supported by the High Fidelity Active Sonar Training (HiFAST) Project at the U.S. Office of Naval Research.]
Vowel confusion patterns in children and adults with cochlear implants
Authors: Jahn Kelly N. , DiNino Mishaela , Winn Matthew , Hulswit Jacob , Arenberg Julie G.
Published: October 2018

Suboptimal interfaces between cochlear implant (CI) electrodes and their target neurons may distort the spectral information that is important for vowel identification. The goal of this investigation was to relate vowel confusion patterns of CI users to their site-specific (i.e., frequency-specific) variation in electrode-neuron interface across the electrode array. The electrode-neuron interface is estimated using single-channel detection thresholds with a spatially focused electrode configuration; elevated thresholds indicate channels with relatively poorer frequency transmission. We hypothesized that higher focused thresholds on channels transmitting low frequency (<983 Hz) information would be associated with errors in vowel height, whereas higher thresholds on channels transmitting mid- and high-frequency (>984 Hz) information would be related to vowel advancement errors. Vowel recognition was assessed with a closed set of medial vowels in 4-talker babble noise. Focused thresholds were measured on electrodes 2–15. Vowel confusions were examined according to the direction of errors in 2-dimensional physical articulatory and acoustic F1-F2 space. Results showed that higher average focused thresholds on the 3 most basal electrodes tested (2327–4630 Hz) were associated with perception of front vowels as more back. These findings suggest that suboptimal electrode-neuron interfaces could systematically affect CI listeners’ perception of vowel characteristics.
Remote microphone system use in the homes of children with hearing loss
Authors: Benitez-Barrera Carlos R. , Angley Gina , Tharpe Anne Marie
Published: October 2018

Remote microphone systems (RMS) are known to improve speech recognition skills of children with hearing loss in settings where noise and distance are present (e.g., the classroom, the home; Bertachini, 2016). However, although RMSs are widely recommended in the classroom setting, very few and inconclusive studies have examined the possible language benefits related to the use of RMS use in the home environment. In this presentation, we will discuss a series of projects in which we investigated the effects of home-use of an RMS on the communication of 10 families with young children with hearing loss. Language Environmental Analysis (LENA™) recorders were used during two consecutive weekends (one weekend with the remote microphone and one without). Caregiver talk, child-directed speech, and other caregiver communication strategies were compared across both weekends. Caregiver perceptions related to RMS use will also be discussed.
Perception of Mandarin Chinese vowels in young hearing-impaired and normal-hearing children
Authors: Zhang Changxin , Liu Chang
Published: October 2018

The study investigated the perception of Mandarin Chinese vowels of 45 congenital hearing-impaired and 45 normal-hearing children aged 4 to 6. There were 30 children at each age group, half of which were hearing-impaired children. All of the hearing-impaired children received hearing aids or cochlear implants before the age of 5. In a picture identification task, listeners identified the target consonant-vowel word among 2–4 contrastive words. The target words and the other contrastive words differed only in consonants. Each target word represented a concrete object and was spoken by a young female native-Chinese talker. Sixteen of the target words ended with monophthong, twenty-two with diphthong and nine with triphthong. Age showed a significant effect on vowel perception for both groups. Normal-hearing children showed significantly better identification of all three types of vowels than hearing-impaired children at the age of 6, whereas the two groups had comparable performance at age of 4 and 5. For hearing-impaired children, a rapid development of diphthong perception occurred between 4 and 5 years old, while a rapid development of monophthong perception between 5 and 6. The effect of hearing loss severity and the use of hearing aids or cochlear implants will be discussed.
Dynamic response sensitivity and variability of a buckling-restrained braced frame under earthquake ground motion
Authors: Magalhaes Max D. , Yang Tony
Published: October 2018

The main goal of this paper is to examine the variability of deformation, stress and energy absorption of a BRBF (Buckling-Restrained Brace Frame) to some dynamic parameters via a parametric study. This study is aimed at providing not only a better understanding of the vibration transmission mechanism in itself but also to produce a useful set of data which for instance can be used by earthquake engineers as input data for a hybrid analysis. This data might be useful for optimizing vibration insulation in buildings at low frequencies, where the modal behaviour of buildings strongly influences the transmission. The results that are discussed in this paper were obtained via simulations using a modal model. The analysis is based on considering the influence of some variations in the "input" parameters, which are required in the pre-processing stage of a numerical experiment, and on the subsequent vibration transmission mechanisms of typical building configurations.
Effects of receptive language ability on the neural representation of phonetic category structure
Authors: Drouin Julia R. , Theodore Rachel M.
Published: October 2018

Speech sound categories have a graded internal structure that reflects typicality of the speech input. Neuroimaging findings reveal dissociable regions for resolving category membership and processing phonetic category structure; frontal regions show increased activation for ambiguous compared to unambiguous exemplars, and temporoparietal regions show increased activation for poor compared to prototypical exemplars, even when category membership is unambiguous. Individuals with developmental language disorder (DLD) show behavioral deficits in some categorization tasks, which may reflect difficulty in organizing auditory information into structured categories. An fMRI paradigm is used to examine whether the neural representation of phonetic category structure reflects receptive language ability. Participants were assigned to either the DLD or control group based on performance for standardized assessments of receptive and expressive language. To assess neural representation of phonetic category structure, participants completed a phonetic categorization task for tokens of bowl and pole using an event-related, sparse-sampling design; voice-onset-times (VOTs) of the pole tokens were manipulated to have values representing an ambiguous exemplar, a prototypical exemplar, and an extreme (i.e., long VOT) exemplar. The analyses will examine whether individuals with DLD show attenuated neural representation of phonetic category structure, and, if so, whether attenuation reflects individual differences in receptive language ability.
Structured phonetic variation facilitates talker identification
Authors: Ganugapati Divya , Theodore Rachel M.
Published: October 2018

Individual talkers systematically differ in their phonetic implementation of speech sounds, and listeners use this structure to facilitate language comprehension. Here we test the hypothesis that listeners’ sensitivity to talker-specific phonetic variation also facilitates voice processing. Listeners completed training and test phases. During training, listeners learned to associate talkers’ voices with cartoon avatars (with feedback). Training stimuli consisted of single-word utterances from two minimal pairs (gain, cane, goal, and coal). In one condition, voice-onset-times (VOTs) of the voiceless-initial words were structured such that each talker had a characteristic VOT. In the other condition, listeners heard the same VOTs, but no talker-specific phonetic structure was present. At test, listeners heard all VOT variants for trained and novel words, and they performed the same voice-avatar identification task (without feedback). The results showed that given limited exposure (one training block), learning of the talkers’ voices was equivalent between the two conditions. However, given extended exposure (three training blocks), talker identification was improved with respect to both accuracy and processing time for listeners who received structured phonetic variation compared to those who did not. These findings suggest that given sufficient time to learn talkers’ idiolects, listeners use structured phonetic variation to facilitate voice processing.
He said, she said: Talker-specific influences on memory for spoken language
Authors: O'Brien Elizabeth , Theodore Rachel M.
Published: October 2018

Memory for spoken language is not a veridical representation of experience. Instead, memory reflects integration across our interlocutors’ messages, resulting in robust memory for meaning with relatively poor memory for specific form. Here we test the hypothesis that talker identity influences how spoken language is integrated in memory. Listeners completed encoding and recognition phases. During encoding, listeners heard sentences that contained constituents of four-part semantic units (i.e., “idea sets”). During recognition, listeners heard novel sentences that contained constituents of each idea set in addition to full idea sets and four-part sentences formed by combining constituents across idea sets (i.e., “noncases”). Across experiments, talker was manipulated in terms of (1) the match between encoding and recognition and (2) the number of talkers during encoding. The results to date replicate evidence of integration during encoding; when talker is held constant, listeners show more false memories at recognition for idea sets compared to constituents, and no false memories for noncases. However, false memories decrease when the talker differs between encoding and recognition, and when listeners hear multiple talkers compared to a single talker during encoding. These findings suggest that talker identity provides a critical structure for the integration of spoken language in memory.
Perceiving audiovisual speech articulation in virtual reality
Authors: Keough Megan , Taylor Ryan C. , Prica Dimitri , Wong Esther Y. , Gick Bryan
Published: October 2018

Listeners incorporate visual speech information produced by computer-simulated faces when the articulations are precise and pre-programmed [e.g., Cohen, & Massaro 1990, Behav. Res. Meth. Instr. Comp. 22(2), 260–263]. Advances in virtual reality (VR) and avatar technologies have created new platforms for face-to-face communication in which visual speech information is presented through avatars. The avatars’ articulatory movements may be generated in real time based on an algorithmic response to acoustic parameters. While the communicative experience in VR has become increasingly realistic, the visual speech articulations remain intentionally imperfect and focused on synchrony to avoid uncanny valley effects [https://developers.facebook.com/videos/f8-2017/the-making-of-facebook-spaces/]. Depending on the VR platform, vowel rounding may be represented reasonably faithfully while mouth opening size may convey gross variation in amplitude. It is unknown whether and how perceivers make use of such underspecified and at times misleading visual cues to speech. The current study investigates whether reliable segmental information can be extracted from visual speech algorithmically generated through a popular VR platform. We report on an experiment using a speech in noise task with audiovisual stimuli in two conditions (with articulatory movement and without) to see whether the visual information improves or degrades identification.
The role of speaker identification in auditory and visual speech recognition: Evidence from twin speech
Authors: Petrich Madeline , Petrich Macie , Lee Chao-Yang , Wiener Seth , Harrison Margaret , Greenlee Sarah
Published: October 2018

Understanding the content of speech does not require identifying speaker voices. Similarly, identifying speaker voices does not require understanding the content of speech. However, ample evidence has shown that speaker voices affect auditory word recognition. Familiarity with speaker voices also affects audiovisual speech recognition. This study examines whether familiarity with twin speakers, who have highly similar voices, affects the magnitude of form priming and that of the McGurk effect. In Experiment 1, participants who were familiar or unfamiliar with the twin speakers performed lexical decision and voice discrimination on pairs of auditory words that were repeated or unrelated. In Experiment 2, the same participants were asked to identify syllables in which auditory and visual information was congruent or incongruent (e.g., auditory /ba/ with visual /ga/). The auditory and visual information was also mixed between the speakers. Experiment 1 showed that familiarity resulted in reduced priming in voice discrimination but not lexical decision. Experiment 2 showed that familiarity did not result in reduced McGurk effect. It appears that the benefit of familiarity in processing auditory and visual speech is compromised when processing highly similar voices. [Work supported by Ohio University PURF and CHSP Student Research Grant.]
Auditory lexical decision in the wild
Authors: Tucker Benjamin V. , Nenadic Filip , Kelley Matthew C.
Published: October 2018

The present report describes a version of the MALD (Massive Auditory Lexical Decision) database which investigates listener performance in the often crowded TELUS World of Science—Edmonton (TWOSE) on tablets with headphones, with most participants experiencing varying levels of uncontrolled distraction. A total of 533 listeners participated in the experiment (ages 4–86; 51% female; 81.8% native English). Stimuli were a randomly selected subset of 2000 words and 2000 pseudowords extracted from the MALD project (Tucker et al., 2018), recorded by a single speaker. The stimuli were further randomly divided into 20 lists, each containing 100 words and 100 pseudowords, with no practice stimuli. Each participant was presented with a single list, with the entire experimental session usually lasting between five and ten minutes. TWOSE-MALD participants, unsurprisingly, perform worse than listeners in a laboratory setting in terms of both accuracy and response latencies. The relationship between the standard predictors and response latency remains the same. We also find age related effects indicating that accuracy increases rapidly (from ages 4 to 14) and slowly plateaus, while response latencies rapidly decrease until participants reach their early twenties, after which a steady increase is noted as participants’ age increases.
Phonetic recalibration of visual and auditory speech by visual sentences
Authors: Dorsi Josh , Rosenblum Lawrence , Chee Sharon
Published: October 2018

Phonetic recalibration is a form of perceptual learning in which experience with an ambiguous speech segment accompanied by disambiguating context biases subsequent perception of that segment. For example, presenting an auditory "f" final word (i.e., “Witlof”; Dutch for “Chicory”) with the final fricative replaced with a sound between /s/ and /f/ results in participants subsequently categorizing more items from a /f/-/s/ continuum as /f/ (Norris, McQueen, Cutler 2003). A similar effect is found for ambiguous visual speech that is accompanied by clear auditory speech (Baart & Vroomen 2010), and for ambiguous auditory speech that is accompanied by clear visual speech (e.g., Vroomen & Baart, 2009). It is unknown whether visual speech alone can recalibrate visual speech segments or whether recalibration in one modality can be transferred to another modality (but see, Dias & Rosenblum 2016). In Experiment 1 of this study we found that sentence context disambiguated a silent visual ambiguous /s/f/ fricative and resulted in visual recalibration. Experiment 2 used these same silent sentences but measured recalibration on an auditory continuum. Preliminary results suggest that recalibration effects can be transferred across modalities in this way. These experiments have implications for theories of amodal perceptual learning.
Lexical access in the face of degraded speech: The effects of cognitive adaptation
Authors: Smith Francis , McMurray Bob
Published: October 2018

Hearing impaired listeners use cognitive adaptations to cope with degraded input. Here, we ask if they adapt processes that normal hearing listeners use to cope with the fact that speech unfolds over time, creating brief periods of ambiguity. Normal listeners cope with this ambiguity by activating multiple lexical candidates which compete for recognition (McClelland & Elman, 1986). These competition dynamics change when processing degraded input (Brouwer & Bradlow, 2016; McMurray, Farris-Trimble, & Rigler, 2017; McQueen & Huettig, 2012), but it is unclear whether this reflects the degraded input itself or cognitive adaptation. In two visual world paradigm experiments, listeners heard different levels of degraded (noise-vocoded) speech. Experiment 1 manipulated the level of degradation either in blocks or randomly interleaved across trials. Interleaving led to processing delays beyond that of the level of degradation: we found switch-costs when degradation levels differed between trials. This suggests differences in lexical dynamics are not solely due to degradation in the input. In Experiment 2, a visual cue indicated the level of degradation before each trial. This reduced the processing delays and switch costs, suggesting participants adapted before the auditory input. These experiments support a role for central processing in dealing with degraded speech input.
Integration of speech information (or not) across electric and acoustic modes in hearing impaired listeners
Authors: Seedorff Michael , McMurray Bob
Published: October 2018

Many people with hearing loss use two cochlear implants (bilateral CIs), or combine a CI and hearing aid (bimodal). While the addition of a second CI or acoustic input improves speech perception (particularly in noise), it is not well understood how listeners fuse these disparate inputs. We addressed this with a duplex perception experiment. Listeners heard the four cardinal vowels from six talkers. In the duplex condition, the first formant was presented to the CI, and the second to the other CI or hearing aid (and vice versa). In normal listeners (N = 14), accuracy under duplex presentation (across ears; M= 0.80) did not differ from combined presentation (both formants, both ears, M = 0.76, p = 0.14), but performance dropped to near chance with isolated formants (M = 0.40, p<0.001). CI users (Bilateral: N = 7; bimodal: N = 11; single-side-of-deafness [SSD]: N = 7) performed well in combined presentation (Bilateral: M = 0.72, Bimodal: M = 0.70, SSD: M = 0.83), and poorly for isolated formants (Bilateral: M = 0.42, Bimodal: M = 0.39, SSD: M = 0.41). Duplex presentation was significantly poorer than combined (Bilateral: M = 0.54, p = 0.0078; Bimodal: M = 0.55, p<0.001; SSD: Duplex: 0.48, p<0.001), though better than isolated formants (p<0.05). Thus, CI users may not fuse inputs well at an auditory level, and the benefits of acoustic + electric hearing may derive from central integration.
Effects of delay time and intensity difference on recognition of overlapped speech sound
Authors: Amano Shigeaki , Yamakawa Kimiko , Maki Katuhiro
Published: October 2018

Speech sound transmitted from an outdoor loudspeaker is sometimes difficult to recognize because it is overlapped by a time-delayed speech sound from other loudspeakers. This difficulty is assumed to depend on a delay time and an intensity difference between the original and overlapping time-delayed sounds. To clarify the effects of a delay time and an intensity difference on speech recognition, a listening experiment was conducted with 21 Japanese adults using 105 Japanese spoken words in a carrier sentence, with delay times and intensity differences ranging between 0–250 ms and 0–9 dB, respectively. The experiment revealed that recognition ratios are significantly lower for delay times of 100–250 ms than for 0 ms. Similarly, the ratios are significantly lower for intensity differences of 0–6 dB than for 9 dB. These results suggest that speech sound from an outdoor loudspeaker is difficult to recognize in a large area where the difference of distances from two loudspeakers ranges between 34 and 85 m and the intensity difference between the original and overlapping time-delayed sound is less than 6 dB. [This study was supported by JSPS KAKENHI Grant Numbers JP15K12494, JP15H03207, JP17K02705, and by Aichi-Shukutoku University Cooperative Research Grant 2017-2018.]
Different musical experiences differentially modulate the auditory-motor processing of feedback errors during vocal production
Authors: Wang Wenda , Liu Hanjun
Published: October 2018

The present study investigated the effects of musical experiences on auditory-motor control of pitch feedback errors during vocal production. Thirty-four female musicians who were assigned to a group of professional signers (n = 17) and a group of instrument players (n = 17) and seventeen female non-musicians aged 18–29 years participated in the present study. All participants vocalized a vowel sound /u/ for about 5-6 seconds while hearing their vocal pitch unexpectedly shifted -50 or -200 cents, and their vocal compensations for pitch perturbations were measured and compared. The results showed significantly larger compensatory vocal responses produced by non-musicians when compared to professional singers (p<0.001) and instrument players (p<0.008). Moreover, instrument players produced significantly larger vocal compensations than professional singers (p = 0.026). The observed effects of musical experiences were independent of the size of pitch perturbation. These findings provide the first behavioral evidence for the differential modulation of vocal compensations for pitch perturbations by different musical experiences, which may be related to the difference between singers and players in extensive vocal training.
Speech intelligibility testing of general service respirators
Authors: Hoeller Christoph , Müller-Trapet Markus , Bradley John S.
Published: October 2018

The communication performance of three general service respirators was evaluated. The evaluation procedure followed a NIOSH standard test procedure which is based on a modified rhyme test (MRT), wherein human participants are placed in a controlled acoustic environment and are asked to read out lists of test words. The number of words correctly identified by a listener panel when the talker is wearing the respirator is compared to the number of words correctly identified without the respirator, giving an overall performance rating. During the implementation of the experimental procedure, it was noted that the NIOSH test procedure is ambiguous on a number of potentially significant acoustical issues, e.g., the reverberation time of the test environment, the background noise spectrum at the listener position, and the talker voice level. This talk will present details of the study and discuss the relevant issues related to speech intelligibility testing of respirators that were evaluated as part of this project.
Measuring the effect of speaker ethnicity on online perception: Evidence from a response time study
Authors: de Weers Noortje
Published: October 2018

The effect of speaker ethnicity on speech perception remains unclear. Proponents of the bias hypothesis maintain that presenting an Asian or Mexican face to American participants triggers a certain kind of bias that could result in worse comprehension and even hearing a non-existent ‘foreign accent.’ Exemplar-based studies, on the other hand, have proposed that these findings merely reflect a mismatch between listeners’ expectations and the actual speech signal. While previous studies all used post-perceptual, offline tasks to examine the effect of speaker ethnicity on speech perception, this study made use of an online task instead. Thirty-two native English participants completed a speeded audio-visual sentence verification task, for which they had to classify statements as true or false. The utterances were paired with a photograph of an Asian face, a White face, or a fixation cross, and were presented in a mixed design. Both correctness scores and response times for all the different face-voice pairings were recorded. Results suggest that online processing was not affected by speaker ethnicity, as response times did not differ as a function of the various face-voice pairings. Additional findings showed that the foreign-accented voices took significantly longer to process than the native voices, and that false statements took longer to answer than true statements.
Acoustic emotion recognition using spectral and temporal features
Authors: Udhan Tejal , Bernadin Shonda
Published: October 2018

In this paper, utility of different low- level, spectral and temporal features is evaluated for the task of emotion recognition. The aim of an ideal speech emotion recognition system is to extract features that are representative of the emotional state of speaker. Pitch, intensity, frequency formants, jitter, and zero crossing rate are five features proposed for characterizing four different emotions, anger, happy, sadness, and neutral. Low- level spectral and temporal features have ease of calculation and limit the complexity of emotion recognition systems since they are commonly single dimensional features. A decision-tree based algorithm is designed for characterizing emotions using these acoustic features. It has been proven that various aspects of a speaker’s physical and emotional state can be identified by speech alone. However, the accuracy of such analyses has not been optimized due to acoustic variabilities such as length and complexity of human speech utterance, gender, speaking styles, and speech rate. Since speech emotion recognition is a developing and challenging field, most powerful features for emotion recognition are not yet defined; hence, investigating the utility of selected features for emotion recognition is an important task.
Proposals of noise-robust spoken words for a broadcast via outdoor loudspeakers
Authors: Yamakawa Kimiko , Amano Shigeaki
Published: October 2018

Spoken words used in a broadcast via outdoor loudspeakers were analyzed in terms of word frequency, word familiarity, and phoneme composition to clarify their characteristics. Based on the analysis, we identified 13 original words that are frequently used but probably difficult to listen to and proposed alternative words having higher word familiarity and a lesser number of noise-intolerant phonemes. To verify the proposal, a listening experiment was conducted. Thirteen each of the original and proposed words were presented with and without pink noise (SNR = 0 dB) to 21 participants with normal hearing ability. Error ratios of word identification were obtained from participants’ responses. In a with-noise condition, the error ratio of the proposed words (7.1%) was significantly lower than that of the original words (18.3%), but no difference in error ratio was observed between the original and proposed words in a without-noise condition. These results indicate that the proposed words have higher noise robustness and less listening difficulty than the original words, and that they are useful for transmitting accurate information in a loudspeaker broadcast.
Optimal use of the visual analog scale: Observations from ratings of emotional speech
Authors: Morgan Shae D.
Published: October 2018

Researchers use many tools to measure participant performance during experiments. The visual analog scale has been used in many areas of research as a valid way to measure listener perception of various aspects of a signal. Ratings using the visual analog scale are commonly averaged over a number of trials to estimate listeners’ perception. This presentation delves into issues which may be encountered when using a visual analog scale for measuring perception of voice (in this case, vocal emotion). An experiment was performed which gathered ratings of emotional activation and pleasantness for many stimuli of four emotion categories (angry, sad, happy, and calm) from 10 listeners. These data will be examined for patterns of variance in a time-course analysis to identify listener certainty or biases created when using the visual analog scale during a long experimental task. Implications of bias and the impact on research results will be discussed along with additional and alternative measurement options for researchers to consider.