bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on interactions between voicing production and perception using auditory feedback paradigm
Authors: Tamura Shunsuke , Mori Miduki , Ito Kazuhito , Hirose Nobuyuki , Mori Shuji
Published: November 2017

A previous study reported that perturbed auditory feedback affected voicing production [Mitsuya, MacDonald, and Munhall (2014). J. Acoust. Soc. Am., 135, 2986–2994]. In this study, we investigated whether perturbed auditory feedback would also affect voicing perception. Eighteen native Japanese speakers participated in the experiment. Half of the participants performed an auditory feedback task in which a syllable sound /da/ was presented simultaneously with the participant’s utterance of /ta/. The other participants did a passive listening task in which participants heard a syllable sound /da/ without the utterance. Before and after each task, participants performed a speech production task of /da/-/ta/ and a speech identification task of /da/-/ta/ continuum stimuli varying in voice-onset time (VOT). Results showed that perturbed auditory feedback lengthened the VOT of /ta/ production, whereas passive listening did not affect voicing production. Regarding voicing perception, passive listening shortened the VOT boundary of /da/-/ta/, which may be due to selective adaptation. On the other hand, perturbed auditory feedback did not vary the boundary. One interpretation of these results is that the effects of voicing production modulation on voicing perception can be cancelled out by selective adaptation, which may have occurred by listening to a syllable sound /da/ during auditory feedback task.
Effect of speaker’s age on perceivers’ ability to predict rounding from AV speech
Authors: Redford Melissa , Kallay Jeffrey
Published: November 2017

We have developed a noninvasive method that synthesizes the complex activity of speaking into a single measure to investigate the scope of anticipatory behavior as this relates to units of execution (Redford, Bogdanov, Vatikiotis-Bateson, 2016). The method leverages work in audio-visual speech perception to identify degree of anticipatory coarticulation at specific temporal locations, manipulated using a gating paradigm. The aim here was to test whether the method was robust to group differences in speakers’ age. Twenty-four college-aged adults judged the presence or absence of rounding in minimal pair sentences produced by 3 adults and 3 five-year-old children based on their AV-recorded speech, gated at different distances from the target rounded/unrounded vowel. Perceivers’ ability to correctly detect an upcoming rounded vowel varied as a function of the prevocalic consonant’s coarticulatory resistance and as a function of distance from target. There was no main effect of age group on perceivers’ accuracy. Age group did however interact with the other factors in that rounding was detected earlier in children’s speech compared to adults’ speech for one of three prevocalic consonants. The results confirm the promise of our method for studying developmental changes in linguistic chunks planned for execution. [Work supported by NICHD # R01HD087452.]
Do older and younger adult listeners show a “clear speech benefit” for speech produced by older adult talkers?
Authors: Hazan Valerie , Tuomainen Outi
Published: November 2017

This study investigates whether a “clear speech benefit” is obtained for speech produced by older (OA) talkers and younger adult (YA) controls in a clear speaking style when heard in babble noise. The speech materials were recorded while OA and YA talkers read BKB sentences to a YA partner who repeated the sentence while hearing normally (NORM) or with a simulated hearing loss (HLS). The HLS condition naturally induced clear speech adaptations. 128 BKB sentences from 4 YA and 4 OA talkers (NORM, HLS) matched on a range of metrics were used in an adaptive listening test tracking the signal-to-noise ratio corresponding to 67% intelligibility. Listeners were 71 native British English listeners: 24 YA (M = 25.2 yrs), 27 OA-NH with normal hearing (M= 71.8), 20 OA-HL with presbyacusis (M= 73.7). Speech perception in noise was hardest for OA listeners, especially from OA-HL. SNR thresholds were significantly lower for YA than for OA voices. The clear speech benefit for HLS speech was only significant for YA voices for all listener groups. In summary, OA talkers were less intelligible than YA talkers regardless of listener age; clear speech adaptations by OA talkers did not result in enhanced intelligibility for OA or YA listeners.
Inhibitory and lexical frequency effects in younger and older adults’ spoken word recognition
Authors: Colby Sarah , Poulton Victoria , Clayards Meghan
Published: November 2017

Older adults are known to have more difficulty recognizing words with dense phonological neighbourhoods (Sommers & Danielson, 1999), suggesting an increased role of inhibition in older adults’ spoken word recognition. Revill and Spieler (2012) found that older adults are particularly susceptible to frequency effects, and will look more to high frequency items compared to younger adults. We aim to replicate and extend the findings of Revill and Spieler (2012) by investigating the role of inhibition along with frequency for resolving lexical competition in both older and younger adults. Older (n = 16) and younger (n = 18) adults completed a visual word paradigm eyetracking task that used high and low frequency targets paired with competitors of opposing frequency, and a Simon task as a measure of inhibition. We find that older adults with poorer inhibition are more distracted by competitors than those with better inhibition and younger adults. This effect is larger for high frequency competitors compared to low. These results have implications for the changing role of inhibition in resolving lexical competition across the adult lifespan and support the idea that decreased inhibition in older adults contributes to increased lexical competition and stronger frequency effects in word recognition.
Does the developing lexicon constrain infants’ discrimination of English vowels?
Authors: Sundara Megha
Published: November 2017

Infants initially discriminate native and non-native contrasts. With perceptual reorganization within the first year of life, discrimination of non-native contrasts reduces while the discrimination of native contrasts improves. Several researchers have proposed distributional learning as a domain-general mechanism by which infants’ acquire phonetic categories (e.g., Saffran et al., 1999; Maye et al., 2002). Recent proposals, however, argue for an interactive mechanism where learning words concurrently, supplements distributional learning of phonetic categories (e.g., Swingley, 2009; Feldman et al., 2013). Not only is this interactive mechanism available during the first year of life, its computational implementations outperform ones based on distributional learning alone (Feldman et al., 2013a; Feldman et al., 2013b). We evaluated predictions of the interactive and distributional learning models against infant discrimination data. Data from 4-, and 8-month-olds, learning (a) only English (b) only Spanish or (c) Spanish and English, tested on English (i) /e- ɛ/ (previously published in Sundara & Scutellaro, 2011), (ii) /i- ɪ/ and (iii) /e- ɪ/, were compared. All stimuli were produced by multiple female talkers from the Hillenbrand corpus; infants were tested using a visual fixation procedure with a habituation criterion of 50%. Our results are consistent with infants using a distributional not interactive learning mechanism.
Representations of speech signals recorded through a dynamic periphery inspired by horseshoe bat biosonar
Authors: Hsu Alexander , Gupta Anupam Kumar , Müller Rolf , Cui Xiaodong , Audhkhasi Kartik , Han Jin-Ping
Published: November 2017

Horseshoe bats have to navigate through complex environments such as dense forests and structure-rich vegetation relying on input from their highly sophisticated biosonar systems. One of the key components of these bats' ability to obtain high-quality acoustic information is to alter the shape of their outer ears rapidly. In prior work, the authors have shown that by mimicking the horseshoe bat rapid ear movements, a bat-inspired robotic dynamic periphery for recording speech signals could enhance speech recognition for limited dataset and also provide estimates for the speaker's direction along with speech recognition. In our current study, we continued to investigate how speech datasets processed by the dynamic periphery may be enhanced compared to a reference by extracting acoustical features through Mel frequency cepstral coefficient (MFCC) transform, Lyon's cochlear bandpass filters, and a neural spike representation, respectively. This study aims to characterize the detailed acoustical differences and quantify the improved speaker intelligence with noise robustness through the dynamic periphery. The ultimate goal of this research is to identify a signal representation that is well suited to capitalize on the time-variant properties of the biomimetic recording periphery and make the dynamic information-bearing features accessible for the classification stages.
Discrete ratings and dimensional judgments of emotional speech: A preliminary look at gender differences
Authors: Morgan Shae D. , Labowe Rebecca
Published: November 2017

Two models of emotion identification and discrimination are not often compared and may show differing trends in how listeners rate emotional stimuli. The discrete or “basic” emotion model posits that emotions are categorical, and that listeners develop auditory prototypes of “basic” emotions (e.g., anger) based on their acoustic profile and past experiences. More complex emotions (e.g., frustration) fall under a “basic” category. The dimensional model examines emotions along continua of different emotional dimensions, such as activation/arousal and pleasantness/valence. The present study introduces the Morgan Emotional Speech Set and examines listener judgments of the stimuli in the corpus. The database consists of 2160 emotional speech sentences (90 sentences x 4 emotions x 6 talkers) produced by three male and three female actors for use in future studies. Each sentence was rated by 10 listeners (5 male, 5 female), who assigned an emotion category to each sentence and also rated each sentence by its activation (low to high) and pleasantness (very unpleasant to very pleasant). Discrete ratings will be compared with dimensional judgments made by listeners to examine intended and perceived emotional content in the database. A preliminary look at gender differences in the ratings and judgments will also be discussed, as male and female listeners may rate emotions differently for same- or different-sex talkers.
Active vs passive moving source tomography: Comparing results from the Santa Barbara Channel Experiment (SBCEx16) on sources of opportunity
Authors: Sarkar Jit , Cornuelle Bruce , Gemba Kay L. , Kuperman William A. , Hodgkiss William S. , Sabra Karim G. , Tippmann Jeffery D. , Verlinden Christopher M.
Published: November 2017

An experiment was performed in the Santa Barbara Channel (SBCEx16) using four vertical line arrays (VLAs) of hydrophones placed midway between the in- and out-going shipping lanes of a maritime highway. The goal of this experiment was to study whether these sources of opportunity can be used for passive tomographic purposes. In addition to the continuous passive observations, active acoustic source-tows were conducted. The environment was monitored continuously throughout the course of the experiment using thermistor strings, and ship tracks were obtained from the Automatic Identification System (AIS). The results from both types of tomography are presented and compared.
Blind deconvolution of sources of opportunity in ocean waveguides using bilinear channel models
Authors: Tian Ning , Romberg Justin , Sabra Karim G.
Published: November 2017

We develop a general algorithmic framework for acoustic imaging using sources of opportunity. While these sources (e.g., ships at known locations) emit high-energy signals, we do not in general have knowledge of the precise waveforms (signatures) of these signals. Consequently, both Channel Impulse Responses (CIRs) and unknown source signals need to be simultaneously estimated from only the recorded signals on a receiver array using blind deconvolution, which is generally an ill-posed problem without any a priori information or additional assumptions about the underlying structure of the CIRs. By exploiting the typical ray-like arrival-time structure of the CIRs between a surface source and the elements of a vertical line array (VLA) in ocean waveguides, we apply a principle component analysis technique to build a bilinear parametric model linking the amplitudes and arrival-times of the CIRs across all channels for a variety of admissible ocean environments. The bilinear channel representation further reduces the dimension of the channel parametric model compared to linear models. We then develop a truncated power interaction deconvolution algorithm by applying the bilinear channel model to the traditional subspace deconvolution method. Numerical and experimental results will demonstrate the robustness of this blind deconvolution methodology.
Experimental demonstration of passive acoustic tracking using a library of nearby sources of opportunity
Authors: Verlinden Christopher M. , Sarkar Jit , Sabra Karim G. , Hodgkiss William S. , Kuperman William A.
Published: November 2017

Acoustic sources can be tracked in the marine environment using a method that is similar to traditional matched field processing but differs in that it uses a library of data-derived replicas in place of modeled replicas. In order to account for differing source spectra between library and target vessels, cross-correlation functions are compared instead of comparing acoustic signals directly. Measured replicas are extrapolated to fully populate a search grid using waveguide invariant theory. The method has been demonstrated experimentally for localizing surface contacts in a shallow water (150 m) environment. Further, we present experimental validation of the method in deeper water and discuss the extension of the technique to sub-surface contacts
Localization of circularly towed sources using machine learning methods
Authors: Reeves Emma , Niu Haiqiang , Gerstoft Peter
Published: November 2017

Localization of a source towed in a circular geometry is accomplished using machine learning methods, wherein the relationship between received pressure and source range is learned directly from the acoustic data. Feed-forward neural networks (FNN), sup- port vector machines (SVM), and random forests (RF) have accurately estimated the range of a source towed in a linear geometry in shallow water (arXiv: 1701.08431v3). Here, we apply FNN, SVM, and RF to a circular source tow using data from the SCEx17 experiment to examine the effect of varying source-receiver geometries. The Sample Covariance Matrix (SCM) is constructed, vectorized and used as the machine learning input. For FNN and RF, these input vectors are combined to form a d x N matrix and an additional preprocessing step is applied to improve classification results. The input matrix is projected onto a d x k basis formed from the top k eigenvectors of its scatter matrix. This compact representation results in improved computation time and performance for FNN and RF compared with using the SCM inputs.
Underwater sound propagation variability over the Chukchi Sea continental slope
Authors: Lin Ying-Tsong , Zhang Weifeng G. , Duda Timothy F. , Ballard Megan S. , Sagers Jason D. , Badiey Mohsen , Worcester Peter F. , Pecknold Sean
Published: November 2017

In the Canada Basin and Chukchi Sea regions, a vertical sound duct can be formed between the Pacific Summer Water Layer on the top and the Atlantic Water Layer on the bottom, providing an acoustic pathway connecting the deep basin and the shallow shelf over the Chukchi Sea continental slope. Previous studies have shown that the shelfbreak circulation (specifically upwelling), the sub-mesoscale eddies spun off the shelfbreak jet, and the ice coverage are the three major causes of the temporal and spatial variability of the Pacific Summer Water Layer in the region. In this paper, numerical simulations utilizing the Parabolic-Equation (PE) method are conducted to investigate the sound propagation variability over the Chukchi Sea shelfbreak and slope, along with an idealized ocean circulation model providing the fundamental basis of water-column fluctuations. The sound pressure sensitivity kernel derived from the acoustic propagator in the PE method is also used to provide physical insights into the sound propagation variability. The acoustic data over the northern Chukchi Sea shelfbreak collected during the 2016 shallow water cruise of the Canada Basin Acoustic Propagation Experiment will be examined and compared with the numerical simulations. [Work supported by the Office of Naval Research.]
Oceanographic measurements on Chukchi shelf break during fall 2016
Authors: Badiey Mohsen , Muenchow Andreas , Eickmeier Justin , Wan Lin
Published: November 2017

During the Canada Basin Acoustic Propagation Experiment (CANAPE) in 2016, two extended shipboard oceanographic measurements were conducted simultaneously with the acoustic propagation from deep water to the Chukchi shelf-break region. These shipboard measurements were aimed at understanding the oceanographic variability including along the shelf eddy formation and upwelling around the shelf break region. We utilize the measured oceanographic data to construct the environmental input for acoustic models. While there was no ice formation or coverage during the observation period, the effects of upwelling and the eddy formation on acoustic propagation were present. This paper demonstrates the results measured in the experiment in the context of temporal and spatial variability of the water column in the Chukchi shelf region. [Work supported by ONR Ocean Acoustics].
Acoustic characterization of the new Arctic using mobile acoustic sources
Authors: Joseph John E. , Reeder D. Benjamin , Doyle Liam J.
Published: November 2017

The Naval Postgraduate School (NPS) participated in Ice Exercise 2016 (ICEX-16), a multi-national naval exercise conducted in the Beaufort Sea during March 2016. Operating at the remote Ice Camp SARGO, NPS deployed several conductivity, temperature and depth (CTD) sensors to capture oceanographic variability to 500 m depth while performing a series of propagation tests. Four mobile mid-frequency sources transmitted signals for approximately 10 hours each to a pair of vertical line array receivers positioned in the field to investigate depth, range, angular and specular characteristics of acoustic propagation and their correlation to variability in oceanographic structure and under-ice conditions. CTD data indicated significant variability in sound speed at 50 m depth where cold, fresh mixed-layer water interfaces with contrasting warm, saline Pacific Summer Water (PSW) that lays immediately below it. The data also show a persistent and stable subsurface sound channel existed as a result of the PSW with peak temperature at 80 m situated above colder Pacific Winter Water (PWW), resulting in a sound channel axis near 140 m depth. Both features have important implications on sonar performance in the Arctic. Modeled and measured transmission loss are compared to quantify the effects.
Limitations of a Gaussian Beam Model for low-frequency acoustic propagation under ice
Authors: Pecknold Sean , McCammon Diana F. , Ellis Dale D.
Published: November 2017

Ray-based propagation models are often used to simulate underwater acoustic communications signals. For longer-range low frequency acoustic communications, particularly under ice cover, it is necessary to determine if a ray-based model can give accurate results. An elastic ice reflection algorithm was added to the Bellhop Gaussian beam model, and the results for mid- and low-frequency propagation were compared to results obtained using a normal modes model adapted for an elastic ice reflection coefficient, and to the OASES wavenumber integration model. The effects of simplified boundary conditions, frequency, and ice thickness on amplitude and phase matching are examined.
Room impulse response synthesis with device diffraction via image source method and finite element analysis
Authors: Meacham Aidan , Unruh Andrew
Published: November 2017

A method to create an accurate reproduction of the soundfield on the surface of a device was developed through the combination of the image source method and anechoic finite element analysis simulations. Typically, the image source method is unable to model diffraction of sound pressure around a device, and it would be impractical to model the wave equation in an entire room with finite element analysis due to computational constraints. By combining the two techniques, however, individual impulse responses from a precomputed finite element dataset can be assembled like image sources to derive transfer functions from sources in space to receivers on the surface of a device. The finite element dataset is comprised of anechoic simulations of plane waves incident on the device, where the number and direction of plane waves are chosen to maximize angular resolution. The direction of arrival from a given image source is matched with a simulated plane wave, and the corresponding anechoic impulse response is delayed and attenuated according to the image source’s time of travel and reflection path. Each reflection is constructed in this manner, and all are summed to create a synthesized reverberant impulse response that accurately portrays diffraction around the device.
Assessment of a variable acoustic system proposal in a real case
Authors: Esmebasi Merve , Tanyer Ali Murat , Caliskan Mehmet
Published: November 2017

This paper is about testing a variable acoustic system proposal under development in a real case. The variable acoustic system is designed as alternating slot panels and prototyped via using Arduino and Processing. Digital interface to control the system is designed in Processing and via Arduino board digital commands are converted to physical movements. After the possibility of construction of variable perforated panel system is simply clarified, perforated panels of the system are produced via CNC routers. Panel positions are defined regarding perforation characteristics in terms of slot width and distances between slots. Changing these parameters is linked to perforation ratio of the system, while air gap and porous material behind are kept unchanged. Sound absorption capabilities of variable perforations are examined with Impedance tube measurements. Measurement results of variable slot panels, as a promising variable acoustic system, are transferred to ODEON room acoustics software, to assess the system in terms of room acoustics. The amphitheater at METU Faculty of Architecture Building, used for different functions from lectures to musical performances, is selected to demonstrate the capability of the proposed variable acoustics system to improve acoustical conditions in an amphitheater.
A concert hall database of US and European halls: Preliminary measurements and results
Authors: Neal Matthew T. , Vigeant Michelle C.
Published: November 2017

Subjective perception in the realm of concert hall acoustics, specifically overall impression, is a difficult problem to approach. Ideally, this type of work should be done using realistic concert hall auralizations, allowing direct comparison of a wide variety of rooms from around the world. Currently, measurements are being taken in concert halls across the United States and in Europe. Halls to be measured were selected from an online survey of researchers and consultants around the United States and Europe. Final selections were made to ensure that a wide variety of hall shapes, sizes, and reverberation times were included in the database, given the available travel resources. Measurements have been made using a 32-element spherical microphone array, a three-way omnidirectional sound source, and a directional sound source. The directional sound source is a 20-element compact array that can reconstruct the frequency-dependent radiation patterns of different orchestral instruments. An overview of the halls included in the database and measurement results will be presented to illustrate the variety within the database. As well, plans for upcoming subjective testing to piece-apart the perception of preference in concert hall acoustics, considering both the hall and individual taste, will be discussed. [Work supported by NSF Award 1302741.]
Overcoming field impact isolation performance failures due to faulty flooring installation practices
Authors: Hale Marlund E.
Published: November 2017

There is very strong demand by new owners of luxury condominiums for hard-surfaced flooring. In some cases, there is a medical need. In most cases, the reasons are personal preference. However, most high-end condominium homeowner associations (HOA) have enacted regulations requiring that upper level dwelling unit owners, making flooring upgrades from any existing flooring to hard-surfaced flooring, meet higher minimum field impact insulation class (FIIC) or impact sound rating (ISR) performance standards than is typically required by building codes. Failure to comply usually causes the HOA to require restoration to prior flooring conditions within a certain time period, with fines and potential litigation for restoration delays. This paper presents field performance test results for several renovated condominiums in different multi-family residential complexes that had successfully passed HOA impact performance tests by using customized sample underlayments and the owners’ desired hard-surfaced flooring, but failed to pass the HOA impact performance requirements after final installation due to faulty installation practices, in spite of explicit verbal and written installation instructions provided to the owners and their flooring contractors. Examples of methods verifying faulty installations are discussed and successful remedies are presented, along with respective passing test results.
VampireVerb: A surreal simulation of the acoustics of Dracula’s Castle
Authors: Chechile Alex , Basica Constantin , Canfield-Dafilou Elliot K. , Abel Jonathan S.
Published: November 2017

This work introduces VampireVerb, a parameterized modal reverberator created from acoustics measurements recorded at Bran Castle in Transylvania, Romania, popularly called “Dracula's Castle.” With limited evening access to the space, balloon pop sources were recorded using an A-format microphone and handheld recorder in several acoustically interesting rooms, including the armory. Spatial impulse responses were estimated from the balloon pop recordings, and a modal reverberator was designed to simulate the measured acoustics. In the main rooms, reverberation times T30 in the range [0.7 s, 1.2 s] were noted. A long, narrow stairwell and the torture chamber were acoustically dry, and did not produce the sound one would typically associate with Dracula's Castle. To bridge this gap between the actual and imagined acoustics, the mode frequencies and dampings were parametrized so as to interactively vary the size of the space and materials present, transforming the recorded rooms into large, stone spaces with the long reverberation times one would expect in Dracula's Castle. Finally, a nonlinear process was embedded in the reverberator architecture, producing a reverberant noise process modulated according to the evolving input signal spectral envelope, thus making VampireVerb both a traditional reverberator, and an instrument for compositional and performance applications.
Calculating a sensitivity kernel for the final cutoff of received energy in a broadband channel impulse response
Authors: Dzieciuch Matthew , Cornuelle Bruce
Published: November 2017

The final cutoff of a deep-water ocean acoustic tomography reception is often interpreted through a modal analysis. An alternative approach is presented here. First, a stable travel-time is generated by using an estimator-correlator to account for the statistical variability of the final low-angle arrival with the assumption of an appropriate coherent bandwidth and depth coherence. A time-series of these travel-times can then be tracked using the Viterbi algorithm. Then, the resolvable, trackable peaks are interpreted using the travel-time sensitivity kernel (TSK). The TSK has been previously used to account for the full-wave effects of ray-like arrivals. But the TSK machinery can be adapted to any processing strategy with the application of the chain-rule. The question of how to interpret an arrival produced by an Estimator-Correlator vs. an arrival produced by standard processing is examined. The feasibility of this approach is first analytically determined with the Pekeris waveguide and then an example from a recent ocean acoustics experiment is presented.
Cross frequency cross mode coherences using transport theory
Authors: P Sivaselvi , Chandrayadula Tarun K. , Colosi John A.
Published: November 2017

Internal waves induced acoustic scattering cause mode coupling. Previous studies on mode scattering effects used narrowband approaches to predict mode energies and time coherences. However, these single-frequency predictions do not explain statistics such as time-wander and multipath spread. In order to address this issue, this paper develops a broadband scattering model that uses the frequency coherences of the modes. For the frequency coherence predictions, this paper uses the physics based transport theory approach. The predictions are setup for an environment similar to the Philippine Sea deep water experiment, which used frequencies around 250 Hz, bandwidth of 100 Hz, and propagation ranges from ~150 km to ~450 km. The physics based predictions are compared with complementary coupled mode based Monte-Carlo simulations. The coherences are used to predict two types of statistics. The first models the time spread for each respective mode. The second uses the cross-frequency cross-mode coherences to predict the stability of the ray time-fronts. The model uses up to mode 75 to predict the multipath time spread in the finale region and a few preceding ray-like arrivals. For the finale region, this paper uses the first 20 modes and the preceding rays 75 modes.
Pulse inversion therapy for improved monitoring of blood-brain barrier opening
Authors: Pouliopoulos Antonios , Burgess Mark , Konofagou Elisa
Published: November 2017

Microbubble-based ultrasound therapy has enabled non-invasive and reversible opening of the blood-brain barrier (BBB). However, the skull limits our ability to monitor microbubble activity due to high attenuation and beam aberrations. In ultrasound imaging, pulse inversion is used to cancel echoes from linear scatterers by summing the signal obtained from consecutive positive (phase: 0o degrees) and negative (phase: 180o degrees) pulses, thus facilitating imaging of non-linear scatterers such as microbubbles. Here, we adapt the pulse inversion technique to improve monitoring of BBB opening, by transmitting consecutive therapeutic pulses of inverse polarity. Pulse inversion therapy (PIT) was achieved by synchronizing the emission of inverted short pulses (pulse length: 2–3 cycles, PRF: 2 kHz, and pressure: 400 kPa) through a focused 0.5 MHz therapeutic transducer driven by two function generators. A concentric P12-5 linear array was used to passively capture the microbubble emissions. Absolute time-of-flight information was introduced in the beamforming since emission and reception were synchronous. PIT suppressed the signals from linear scatterers within the focal region by up to 6 dB in a gelatine phantom containing microbubbles and in mice in vivo, compared to positive-only pulses. Ongoing in vivo work aims at correlating the BBB opening with the microbubble signal identified by PIT.
Investigation of molecular mechanisms induced by a combination of high-intensity focused ultrasound and chemical anti-cancer agents
Authors: Yu Heng , Murad Hakm Y. , Luo Daishen , Sholl Andrew , Khismatullin Damir
Published: November 2017

Tumor exposure to a combination of chemical treatment and physical forces causes chemical modifications and structural changes in cancer cells which inhibit their ability to survive and proliferate. High-Intensity focused ultrasound (HIFU), a unique non-invasive and non-ionizing physical force modality, has great potential as an adjuvant for chemical anti-cancer therapy. In vitro and in vivo studies conducted in our laboratory showed that HIFU synergistically enhanced tumor destruction by ethanol injection or chemotherapeutic drugs and reduce the potential for tumor metastasis. The objective of this study was to investigate the molecular mechanisms behind adjuvant anti-cancer effects of HIFU. To do this, we employed a combination of flow cytometry and western-blot analysis as well as in vitro and in vivo assays of tumor growth and cell adhesion. We showed HIFU drastically reduced the metastatic potential of chemically treated cancer cells via overproduction of heat-shock protein 70 (HSP70), death receptor Fas, its ligand FasL and TNF-α receptor. Although Hsp70 plays a key role in cancer initiation and progression, its overproduction induced by HIFU interferes with NF-κB signaling, thereby causing apoptosis and reduced expression of adhesion molecules required for metastasis. All these factors lead to phenotypic changes in surviving cancer cells that reduce their aggressiveness.
Development of a treatment simulation platform—Application to probe optimization and tissues characterization
Authors: Loyet Raphaël , Chatillon Sylvain , Chavrier Françoise , sifferlen loic , Bouakaz Ayache , Leberre Stéphane , Calmon Pierre
Published: November 2017

In order to ease the development and optimization of new transducers and therapeutic protocols, a unified tool to easily simulate 3D pressure fields created by HIFU in human tissues has been developed jointly by INSERM and CEA-LIST. This includes three propagation algorithms: 1/ a GPU implementation of Rayleigh integral for fast linear propagation in human soft tissues, 2/ a dynamic ray tracing algorithm for the simulation of propagation in heterogeneous or inhomogeneous media (i.e., bones, skull, heated tissues, etc.), 3/ a Westervelt solver for non-linear propagation. These algorithms have been validated and implemented in a unified graphical user interface and can be easily interchanged to compare the results or to target a specific research topic. A finite volume difference solver for Bio Heat Transfer Equation (BHTE) has also been implemented. It can be used with all the HIFU propagation algorithms. It is used to simulate thermal effects of HIFUs and thermal dose in tissues and phantoms. Parametric studies targeting probe optimization and better characterization of tissues will be presented. [Work supported by French Nation Research Agency (ANR SATURN -15-CE19-0016).]
Experimental measurements and bristle friction modeling of nonlinear hysteresis loops and harmonic generation in rock fractures
Authors: Saltiel Seth , Bonner Brian , Mittal Tushar , Delbridge Brent , Ajo-Franklin Jonathan
Published: November 2017

Frictional properties affect the propagation of high-amplitude seismic waves across rock fractures. Laboratory evidence suggests that these properties can be measured in active seismic surveys, potentially offering a route to characterizing friction in situ. We present experimental results from a subresonance torsional modulus and attenuation apparatus that utilizes micron-scale sinusoidal oscillations to probe the nonlinear stress-strain relation at a range of strain amplitudes and rates. Nonlinear effects are further quantified using harmonic distortion; however, time series data best illuminate underlying physical processes. The low-frequency stress-strain hysteretic loops show stiffening at the sinusoid’s static ends, but stiffening is reduced above a threshold frequency. This shape is determined by harmonic generation in the strain; the stress signal has no harmonics, confirming that the fractured sample is the source of the nonlinearity. These qualitative observations suggest the presence of rate-dependent friction and are consistent between fractures in three different rock types. We propose that static friction at the low strain rate part of the cycle, when given sufficient “healing” time at low oscillation frequencies, causes this stiffening cusp shape in the hysteresis loop. While rate-and-state friction is commonly used to represent dynamic friction, it cannot capture static friction or negative slip velocities. So, we implement a bristle friction model, which describes this process and produces similar results.
Flaw detection of wellbore systems by combining time reversal methods and nonlinear acoustic measurements
Authors: Donahue Carly M. , Le Bas Pierre-yves
Published: November 2017

A wellbore system consisting of a steel pipe cased in cement is susceptible to cracking and delamination. Such flaws greatly reduce the integrity of the wellbore and can lead to significant leakage. To resolve the location and extent of the defects, we have combined a unique time reversal method with nonlinear acoustic evaluation. The time reversal method generates a compact high-amplitude wave only in a localized area that can be used to probe the acoustic properties spot by spot of a three dimensional region. Additionally, the nonlinear acoustic signal an object exhibits is far more sensitive to damage and defects than conventional linear analysis. The nonlinear behavior can be locally determined by observing the changes in elastic properties as the amplitude of the time-reversed focus wave is increased. The experimental setup consist of an array of piezoelectric transducers for generating the focused energy and a laser vibrometer mounted on a scanning frame for focusing and measuring nonlinearity on the interior of the steel tubing.
The soil plate oscillator: Nonlinear mesoscopic elasticity of layers of glass beads in flexural vibration
Authors: Santos Emily V. , Korman Murray S.
Published: November 2017

The soil plate oscillator (SPO) apparatus consists of two circular flanges sandwiching and clamping a thin circular elastic plate. In this presentation, uniform spherical glass beads—representing a nonlinear mesoscopic elastic material—are supported at the bottom by the plate and stiff cylindrical sidewalls of the upper flange. A small magnetic disk centered and fastened below the plate is driven by an AC coil placed below the magnet. Nonlinear tuning curves of the magnet’s acceleration are measured by driving the coil with a swept sinusoidal signal applied to a constant current amplifier. Experiments are first performed to measure the peak resonant frequency vs. mass loading as glass beads are added to make a level column above the plate. Experiments are repeated using 1,2,3,…,10 mm diameter beads to demonstrate how the frequency first decreases and then eventually increases for each bead diameter. Next, ten (separate) tuning curve experiments are performed using a fixed column of 350 grams of beads for each diameter. The backbone curves (peak acceleration vs. corresponding resonant frequency) exhibit a linear region with comparable slopes. While the detailed curvature vs. bead diameter reveals more structure, a bilinear hysteresis model fits the results.
Context effects on accentedness ratings
Authors: Vaughn Charlotte , Baese-Berk Melissa M.
Published: November 2017

Intelligibility and accentedness are largely independent judgments (Derwing & Munro, 1995); a speaker rated as highly accented can be quite intelligible. The context of listeners’ exposure to accented speakers has been shown to affect adaptation to speakers in terms of intelligibility (e.g., Tzeng et al., 2016), suggesting that implicit comparison between examples facilitates learning of systematic properties of accented speech. However, it is unknown whether context affects accentedness ratings, which are often assumed to be stable properties of speakers. To better understand the susceptibility of accent ratings to context effects, the present study examines listeners’ accentedness judgments of native and non-native speech taken from the ALLSSTAR Corpus (Bradlow et al., 2010). A target set of the same accented speech samples was embedded in a variety of task contexts, varying whether the stimuli were randomized among speakers or blocked by speaker, or presented at the beginning or end of the experiment. Results will shed light on how stable accentedness judgments are, and begin to test the extent to which these judgments are tied to particular items, speakers, accents, or listeners. Determining whether accentedness ratings are affected by context is a step toward understanding what factors listeners use when making accentedness ratings.
Effect of frequency shifts on talker recognition in native and foreign-accented speech
Authors: Kapolowicz Michelle R. , Guest Daniel R. , Montazeri Vahid , Assmann Peter F.
Published: November 2017

The present study examined the effect of frequency shifts on perceived talker recognition in foreign-accented speech compared to native-accented speech. Sentences were processed using the STRAIGHT vocoder. The spectral envelope and the fundamental frequency were shifted up or down in seven steps (3 up, 3 down plus unshifted) using scale factors of 8% and 30%, respectively, at each step. Listeners heard pairs of sentences and were asked to judge whether the identity of the talker was the same or different. Frequency shifts had similar effects for native- and foreign-accent conditions, in that listeners perceived the shifted versions as different talkers when, in fact, the talkers were the same. However, listeners were more likely to judge native-accented sentence pairs as the same talker regardless of whether or not they were the same; foreign-accented sentence pairs were more likely to be heard as different talkers. Overall, these results indicate that patterns of frequency-shifted foreign-accented speech are similar to previously reported patterns for frequency-shifted native speech; however, the small differences in patterns between the accent conditions might be attributed to listeners being less familiar with non-native speech patterns.
Towards automated detection of similarities and differences in bilingual speakers
Authors: Speights Marisha , Silbert Noah H. , MacAuslan Joel , Blades Rachel , Maya Donaldson , Swanson Kara , Tuohy Sarah , Ungruhe JoHannah , Washington Karla
Published: November 2017

Bilingualism is increasingly the norm in the United States with at least 20% of Americans being bilingual. This change in linguistic demography has created a new challenge to accurately diagnose speech disorders among bilingual children. This study explores Acoustic Landmark Detection (ALD) system as an objective approach to characterizing similarities and differences in speech production in child speakers of Standard English and Jamaican Creole (JC). Eight JC-English bilingual children were recorded speaking eleven words three times in each language. Words were transcribed and entered into PROPH + to provide: (1) Phonological Mean Length of Utterance [pMLU], (2) phonotactic structure, and (3) Percent Consonants Correct (PCC). Landmarks were hand-marked to determine probable landmark sequences based on canonical word production. Canonical landmark sequences were aligned with detected landmark sequences in both languages using the Needleman-Wunsch global alignment algorithm. Analysis revealed that if PCC indicates JC and English words are different, the mismatch between landmark tends to be lower (higher production accuracy); if phonotactics indicate JC and English words are different, mismatch tends to be slightly higher (lower accuracy); and if pMLU indicates word differences, mismatch tends to be higher (lower accuracy). Our finding support traditional linguistic expectations regarding bilingual speakers’ similarities and differences.
Should coastal planners have concern over where land ice is melting?
Authors: Larour Eric , Ivins Erik R. , Adhikari Surendra
Published: November 2017

We show how coastal planners can use sea-level gradient fingerprints to inform mitigation efforts for their local port city.
Vasohibins/SVBP are tubulin carboxypeptidases (TCPs) that regulate neuron differentiation
Authors: Aillaud Chrystelle , Bosc Christophe , Peris Leticia , Bosson Anouk , Heemeryck Pierre , Van Dijk Juliette , Le Friec Julien , Boulan Benoit , Vossier Frédérique , Sanman Laura E. , Syed Salahuddin , Amara Neri , Couté Yohann , Lafanechère Laurence , Denarier Eric , Delphin Christian , Pelletier Laurent , Humbert Sandrine , Bogyo Matthew , Andrieux Annie , Rogowski Krzysztof , Moutin Marie-Jo
Published: November 2017

Tubulin carboxypeptidase identity revealed

Enzymes of the α-tubulin detyrosination/tyrosination cycle create landmarks on microtubules that are essential for their multiple cellular functions and are altered in disease. Tubulin carboxypeptidases (TCPs) responsible for detyrosination have remained elusive for 40 years (see the Perspective by Akhmanova and Maiato). Aillaud
et al.
identified vasohibins as enzymes that perform the TCP function and found that their small interacting partner SBVP was essential for their activity. Vasohibin/SVBP complexes were involved in neuron polarization and brain cortex development. The authors also developed an inhibitor targeting this family of enzymes. Using a completely different strategy, Nieuwenhuis
et al.
also showed that vasohibins can remove the C-terminal tyrosine of α-tubulin.

Science
, this issue p.
1448
, p.
1453
; see also p.
1381
Vasohibins encode tubulin detyrosinating activity
Authors: Nieuwenhuis Joppe , Adamopoulos Athanassios , Bleijerveld Onno B. , Mazouzi Abdelghani , Stickel Elmer , Celie Patrick , Altelaar Maarten , Knipscheer Puck , Perrakis Anastassis , Blomen Vincent A. , Brummelkamp Thijn R.
Published: November 2017

Tubulin carboxypeptidase identity revealed

Enzymes of the α-tubulin detyrosination/tyrosination cycle create landmarks on microtubules that are essential for their multiple cellular functions and are altered in disease. Tubulin carboxypeptidases (TCPs) responsible for detyrosination have remained elusive for 40 years (see the Perspective by Akhmanova and Maiato). Aillaud
et al.
identified vasohibins as enzymes that perform the TCP function and found that their small interacting partner SBVP was essential for their activity. Vasohibin/SVBP complexes were involved in neuron polarization and brain cortex development. The authors also developed an inhibitor targeting this family of enzymes. Using a completely different strategy, Nieuwenhuis
et al.
also showed that vasohibins can remove the C-terminal tyrosine of α-tubulin.

Science
, this issue p.
1448
, p.
1453
; see also p.
1381
Postcatalytic spliceosome structure reveals mechanism of 3′–splice site selection
Authors: Wilkinson Max E. , Fica Sebastian M. , Galej Wojciech P. , Norman Christine M. , Newman Andrew J. , Nagai Kiyoshi
Published: November 2017

Understanding splicing from the 3′ end

The spliceosome removes introns from eukaryotic mRNA precursors and yields mature transcripts by joining exons. Despite decades of functional studies and recent progress in understanding the spliceosome structure, the mechanism by which the 3′ splice site (SS) is recognized by the spliceosome has remained unclear. Liu
et al.
and Wilkinson
et al.
report the high-resolution cryo-electron microscopy structures of the yeast postcatalytic spliceosome. The structures reveal that the 3′SS is recognized through non-Watson-Crick base pairing with the 5′SS and the branch point, stabilized by the intron region and protein factors.

Science
, this issue p.
1278
, p.
1283