bluuebunny/crossref_metadata_2025 huggingface dataset:
The Impact of Time on Predicate Forms in the Manual Modality: Signers, Homesigners, and Silent Gesturers
Authors: Goldin‐Meadow Susan
Published: October 2014

It is difficult to create spoken forms that can be understood on the spot. But the manual modality, in large part because of its iconic potential, allows us to construct forms that are immediately understood, thus requiring essentially no time to develop. This paper contrasts manual forms for actions produced over three time spans—by silent gesturers who are asked to invent gestures on the spot; by homesigners who have created gesture systems over their life spans; and by signers who have learned a conventional sign language from other signers—and finds that properties of the predicate differ across these time spans. Silent gesturers use location to establish co‐reference in the way established sign languages do, but they show little evidence of the segmentation sign languages display in motion forms for manner and path, and little evidence of the finger complexity sign languages display in handshapes in predicates representing events. Homesigners, in contrast, not only use location to establish co‐reference but also display segmentation in their motion forms for manner and path and finger complexity in their object handshapes, although they have not yet decreased finger complexity to the levels found in sign languages in their handling handshapes. The manual modality thus allows us to watch language as it grows, offering insight into factors that may have shaped and may continue to shape human language.
α‐Synuclein forms non‐selective cation channels and stimulates ATP‐sensitive potassium channels in hippocampal neurons
Authors: Mironov Sergej L.
Published: October 2014

Key points

In Parkinson's disease, the protein α‐synuclein (αS) is produced within neurons and also appears in the extracellular fluid.

In this study in hippocampal neurons, αS formed non‐selective cation channels with multiple levels of conductance and rectification depending on their insertion site.

αS channels induced local spontaneous increases in intracellular Na+ and Ca2+, depolarized neurons, augmented bursting activity and stimulated the opening of ATP‐sensitive K+ channels.

Non‐selective channels were also observed in neurons transfected with either wild‐type or mutant A53T αS, and after extracellular application of these proteins.

The properties of αS channels in neuronal membranes suggest that extracellular αS is more toxic than αS produced within neurons.

In Parkinson's disease and several other neurodegenerative diseases, the protein α‐synuclein (αS) is produced within neurons and accumulates in the extracellular fluid. Several mechanisms of αS action are proposed, one of which is the formation of cation‐permeable pores that may mediate toxicity. αS induces non‐selective cation channels in lipid bilayers, but whether this occurs in living neurons and which properties the channels possess have not yet been examined. In this study the properties of αS channels in dissociated hippocampal neurons are documented. In cell‐attached recordings the incorporation of αS into membranes was driven by applied negative potentials. These channels exhibited multiple levels of conductance (30, 70 and 120 pS at −100 mV) and inward rectification. The persistent activity of αS channels induced local changes in intracellular Na+ and Ca2+, depolarized neurons and augmented bursting activity. αS channels formed by adding αS to the intracellular membrane in inside‐out patches exhibited outward rectification. αS channels were equally permeable to Na+, K+ and Ca2+. These channels were also observed in neurons transfected with wild‐type or mutant A53T αS, and after extracellular application of wild‐type or mutant A53T αS proteins. Opening of αS channels stimulated opening of ATP‐sensitive K+ (KATP ) channels and did not interfere with the activity of delayed rectifier K+ channels. The properties of αS channels in neuronal membranes suggest stronger toxicity of extracellularly applied αS than intracellular αS. Enhancement of neuronal excitability and distortions in ion homeostasis may underlie the toxic effects of αS that can be dampened by KATP channels.
Recent results on sonic crystals for sound guiding and acoustic absorption
Authors: Sanchez-Dehesa Jose , García-Chocano Victor M. , Guild Matthew D.
Published: October 2014

We report on different aspects of the behavior of sonic crystals with finite size. First, at wavelengths on the order of the lattice period we have observed the excitation of deaf modes, i.e., modes with symmetry orthogonal to that of the exciting beam. Numerical simulations and experiments performed with samples made of three rows of cylindrical scatterers demonstrate the excitation of sound waves guided along a direction perpendicular to the incident beam. Moreover, the wave propagation inside the sonic crystal is strongly dependent on the porosity of the building units. This finding can be used to enhance the absorbing properties of the crystal. Also, we will discuss the properties of finite sonic crystals at low frequencies, where we have observed small period oscillations superimposed on the well-known Fabry-Perot resonances appearing in the reflectance and transmittance spectra. It will be shown that the additional oscillations are due to diffraction in combination with the excitation of the transverse modes associated with the finite size of the samples. [Work supported by ONR.]
The influence of thermal and viscous effects on the effective properties of an array of slits
Authors: Smith John D. , Sambles Roy , Ward Gareth P. , Murray Alastair R.
Published: October 2014

A system consisting of an array of thin plates separated by air gaps is examined using the method of asymptotic homogenization. The effective properties are compared with a finite element model and experimental results for the resonant transmission of both a single slit and an array of slits. These results show a dramatic reduction in the frequency of resonant transmission when the slit is narrowed to below around one percent of the wavelength due to viscous and thermal effects reducing the effective sound velocity through the slits. These effects are still significant for slit widths substantially greater than the thickness of the boundary layer.
Tunable resonator arrays—Transmission, near-field interactions, and effective property extraction
Authors: Smirnov Dmitry , Umnova Olga
Published: October 2014

Periodic arrays of slotted cylinders have been studied with a focus on analytical and semi-analytical techniques, observing near-field interactions and their influence on reflection and transmission of acoustic waves by the array. Relative orientation of the cylinders within a unit cell has been shown to strongly affect the array behavior, facilitating tunable transmission gaps. An improved homogenization method is proposed and used to determine effective properties of the array, allowing accurate and computationally efficient prediction of reflection and transmission characteristics of any number of rows at arbitrary incidence.
F-35A and F-35B aircraft ground run-up acoustic emissions
Authors: James Michael M. , Downing Micah , Salton Alexandria R. , Gee Kent L. , Neilsen Tracianne B. , McKinley Richard L. , Wall Alan T. , Gallagher Hilary L.
Published: October 2014

A multi-organizational effort led by the Air Force Research Laboratory conducted acoustic emissions measurements on the F-35A and F 35B aircraft at Edwards Air Force Base, California, in September 2013. These measurements followed American National Standards Institute/Acoustical Society of America S12.75-2012 to collect noise data for community noise models and noise exposures to aircraft personnel. In total, over 200 unique locations were measured with over 300 high fidelity microphones. Multiple microphone arrays were deployed in three orientations: circular arcs, linear offsets from the jet-axis centerline, and linear offsets from the jet shear layer. The microphone arrays ranged from distances 10 ft outside the shear layer to 4000 ft from the aircraft with angular positions ranging from 0° (aircraft nose) to 160° (edge of the exhaust flow field). A description of the ground run-up acoustic measurements, data processing, and the resultant data set is provided.
Efficient jet noise models using the one-way Euler equations
Authors: Towne Aaron , Colonius Tim
Published: October 2014

Experimental and numerical investigations have correlated large-scale coherent structures in turbulent jets with acoustic radiation to downstream angles, where sound is most intense. These structures can be modeled as linear instability modes of the turbulent mean flow. The parabolized stability equations have been successfully used to estimate the near-field evolution of these modes, but are unable to properly capture the acoustic field. We have recently developed an efficient method for calculating these linear modes that properly captures the acoustic field. The linearized Euler equations are modified such that all upstream propagating acoustic modes are removed from the operator. The resulting equations, called one-way Euler equations, can be stably and efficiently solved in the frequency domain as a spatial initial value problem in which initial perturbations are specified at the flow inlet and propagated downstream by integrating the equations. We demonstrate the accuracy and efficiency of the method by using it to model sound generation and propagation in jets. The results are compared to accurate large-eddy-simulation data for both subsonic and supersonic jets.
Testing AutoTrace: A machine-learning approach to automated tongue contour data extraction
Authors: Hahn-Powell Gustave V. , Archangeli Diana
Published: October 2014

While ultrasound provides a remarkable tool for tracking the tongue's movements during speech, it has yet to emerge as the powerful research tool it could be. A major roadblock is that the means of appropriately labeling images is a laborious, time-intensive undertaking. In earlier work, Fasel and Berry (2010) introduced a "translational" deep belief network (tDBN) approach to automated labeling of ultrasound images of the tongue, and tested it against a single-speaker set of 3209 images. This study tests the same methodology against a much larger data set (about 40,000 images), using data collected for different studies with multiple speakers and multiple languages. Retraining a “generic” network with a small set of the most erroneously labeled images from language-specific development sets resulted in an almost three-fold increase in precision in the three test cases examined.
The fluid–structure interaction technique specialized to axially symmetric targets
Authors: Abawi Ahmad T. , Krysl Petr
Published: October 2014

The fluid–structure interaction technique provides a paradigm for solving scattering from elastic targets embedded in a fluid by a combination of finite and boundary element methods. In this technique, the finite element method is used to compute the target’s impedance matrix and the Helmholtz–Kirchhoff integral with the appropriate Green’s function is used to represent the field in the exterior medium. The two equations are coupled at the surface of the target by imposing the continuity of pressure and normal displacement. This results in a Helmholtz–Kirchhoff boundary element equation that can be used to compute the scattered field anywhere in the surrounding environment. This method reduces a finite element problem to a boundary element one with drastic reduction in the number of unknowns, which translates to a significant reduction in numerical cost. This method was developed and tested for general 3D targets. In this paper, the method is specialized to axially symmetric targets, which provides further reduction in numerical cost, and validated using benchmark solutions.
Bridging the gap between eyes and ears with auralization
Authors: Glosemeyer Petrone Robin S. , Pfeiffer Scott D. , Mayell Marcus
Published: October 2014

Ray trace animation, level plots, and impulse responses, while all useful tools in providing a visual representation of sound, do not always bridge the gap between the eye and ear. Threshold utilized auralization to inform decisions for an upcoming theater renovation with the goal of improving the room’s acoustic support of orchestral performance. To achieve the desired acoustic response, the renovation will require major modifications to the shaping of a hall with a very distinctive architectural vernacular; a distinctive vernacular that will need to be preserved in some form to maintain the facility’s identity. Along with other modeling tools, auralization provided useful support, reassuring both the client and the design team of the validity of the concepts.
Extended tools for simulated impulse responses
Authors: Ahnert Wolfgang , Feistel Stefan
Published: October 2014

To calculate impulse responses is already done since more than 25 years. The routines did allow simple calculations without and now always with scattered sound components. Today, sophistic routines calculate frequency-dependent full impulse responses comparable with measured ones. Parallel to this development, auralization routines have been developed first for monaural and binaural reproduction and nowadays ambisonic signals are created in B-Format of first and second order. These signals make audible during the reproduction in an ambisonic playback configuration the distribution of wall and ceiling reflections in computer models in EASE. Beside the acoustic detection of desired or unwanted reflections, which always is asking for the correct reproduction of the ambisonic signals the visualization of the reflection distribution is desired. In EASE, a new tool has been implemented to correlate the reflections in an impulse response with their position in a 3D presentation. This new hedgehog presentation of full impulse responses correlates angle-dependent with the view position of the model. So, any wanted or unwanted reflections may be identified quickly. A comparison with ambisonic signals via auralization is possible.
Using auralization to evaluate the decay characteristics that impact intelligibility in a school auditorium
Authors: Olson Bruce C. , Olson Bruce C.
Published: October 2014

Auralization was used to evaluate the effectiveness of the loudspeaker design in a high school auditorium to provide good speech intelligibility when used for lectures. The goals of this project where to offer an aural impression that enhances the visual printouts of the simulation results from the 3D model of the space in EASE using the Analysis Utility for Room Acoustics. The process used will be described and some of the results will be presented.
Vibrolization: Simulating whole-body structural vibration for clients and colleagues with the Motion Platform
Authors: Abercrombie Clemeth , Wilcock Tom , Morgan Andrew
Published: October 2014

Arup has recently introduced an experiential design tool for demonstrating whole-body vibration. The Motion Platform, a bespoke simulator, moves vertically and can reproduce structural vibration in buildings, transport, and any other situations that involve shaking. Beyond humans, the platform can also shake objects—opening the door for developing new vibration criteria for devices such as video cameras and projectors. We will share our experience in developing the platform and how it has helped us communicate design ideas to clients and design team members.
Exploiting the sound-speed minimum to extend tracking ranges of vertical arrays in deep water environments
Authors: Thode Aaron , Mathias Delphine , Straley Janice , Andrews Russel D. , Lunsford Chris , Moran John , Sarkar Jit , Verlinden Chris , Hodgkiss William , Kuperman William
Published: October 2014

Underwater acoustic vertical arrays can localize sounds by measuring the vertical elevation angles of various multipath arrivals generated by reflections from the ocean surface and bottom. This information, along with measurements of the relative arrival times of the multipath, can be sufficient for obtaining the range and depth of an acoustic source. At ranges beyond a few kilometers ray refraction effects add additional multipath possibilities; in particular, the existence of a sound-speed minimum in deeper waters permits purely refracted ray arrivals to be detected and distinguished on an array, greatly extending the tracking range for short-aperture systems. Here, two experimental vertical array deployments are presented. The first is a simple two-element system, deployed using longline fishing gear off Sitka, AK. By tracking a tagged sperm whale, this system demonstrated an ability to localize this species out to 35 km range, and provide estimates of the detection range of these animals as a function of sea state. The second deployment—a field trial of an 128-element, mid-frequency vertical array system off Southern California—illustrates how multi-element array gain can further extend the detection and tracking ranges of sperm and humpback whales in deep-water environments. [Work supported by NPRB, NOAA, and ONR.]
Baleen whale localization using hydrophone streamers during seismic reflection surveys
Authors: Abadi Shima H. , Tolstoy Maya , Wilcock William S. D. , Crone Timothy J. , Carbotte Suzanne M.
Published: October 2014

Seismic reflection surveys use acoustic energy to image the structure beneath the seafloor, but concern has been raised about their potential impact on marine animals. Most of the energy from seismic surveys is low frequency, so the concern about their impact is focused on Baleen whales that communicate in the same frequency range. To better mitigate against this impact, safety radii are established based on the criteria defined by the National Marine Fisheries Service. Marine mammal observers use visual and acoustic techniques to monitor safety radii during each experiment. However, additional acoustic monitoring, in particular, locating marine mammals, could demonstrate the effectiveness of the observations, and help us understand animal responses to seismic experiments. A novel sound source localization technique using a seismic streamer has been developed. Data from seismic reflection surveys conducted with the R/V Langseth are being analyzed with this method to locate baleen whales and verify the accuracy of visual detections during experiments. The streamer is 8 km long with 636 hydrophones sampled at 500 Hz. The work focuses on time intervals when only a mitigation gun is firing because of marine mammal sightings. [Sponsored by NSF.]
Using a coherent hydrophone array for observing sperm whale range, classification, and shallow-water dive profiles
Authors: Tran Duong D. , Huang Wei , Bohn Alexander C. , Wang Delin , Gong Zheng , Makris Nicholas C. , Ratilal Purnima
Published: October 2014

Sperm whales in the New England continental shelf and slope were passively localized, in both range and bearing, and classified using a single low-frequency (<2500 Hz), densely sampled, towed horizontal coherent hydrophone array system. Whale bearings were estimated using time-domain beamforming that provided high coherent array gain in sperm whale click signal-to-noise ratio. Whale ranges from the receiver array center were estimated using the moving array triangulation technique from a sequence of whale bearing measurements. Multiple concurrently vocalizing sperm whales, in the far-field of the horizontal receiver array, were distinguished and classified based on their horizontal spatial locations and the inter-pulse intervals of their vocalized click signals. The dive profile was estimated for a sperm whale in the shallow waters of the Gulf of Maine with 160 m water-column depth located close to the array's near-field where depth estimation was feasible by employing time difference of arrival of the direct and multiply reflected click signals received on the horizontal array. By accounting for transmission loss modeled using an ocean waveguide-acoustic propagation model, the sperm whale detection range was found to exceed 60 km in low to moderate sea state conditions after coherent array processing.
Long duration ultrasound facilitates delivery of a therapeutic agent
Authors: Stratton Kelly , Taggart Rebecca , Lewis George K.
Published: October 2014

The ability for ultrasound to enhance drug delivery through the skin has been established in an animal model. This research tested the delivery of a therapeutic agent into human skin using sustained ultrasonic application over multiple hours. An IRB-approved pilot study was conducted using hyalaronan, a polymer found in the skin and associated with hydration. To assess the effectiveness of the delivery, a standard protocol was applied to measure moisture of the volar forearm with a corneometer. Fifteen subjects applied the hyalaronan to their forearms daily. One location was then treated with a multi-hour ultrasonic treatment, and the other was not. Baseline skin hydration measurements were taken for one week, followed by daily treatments with moisturizer and corneometer measurements twice per week for three weeks. Subjects experienced double the increase in sustained moisture when ultrasound was used in conjunction with a moisturizer when compared to moisturizer alone (p<0.001) over the four weeks. This study successfully demonstrated ultrasound treatment enhanced delivery of a therapeutic agent into the skin.
An improved time-base transformation scheme for computing waveform deformation during nonlinear propagation of ultrasound
Authors: de Graaff Boris , Raghunathan Shreyas B. , Verweij Martin D.
Published: October 2014

Nonlinear propagation plays an important role in various applications of medical ultrasound, like higher harmonic imaging and high intensity focused ultrasound (HIFU) treatment. Simulation of nonlinear ultrasound fields can greatly assist in explaining experimental observations and in predicting the performance of novel procedures and devices. Many numerical simulations are based on the generic split-step approach, which takes the ultrasound field at the transducer plane and propagates this forward over successive parallel planes. Usually, the spatial steps between the planes are small and the diffraction, attenuation, and nonlinear deformation may be treated as separate substeps. For the majority of methods, e.g., for all KZK-type methods, the nonlinear substep relies on the implicit solution of the one-dimensional Burgers equation, which is implemented using a time-base transformation. This generally works fine, but when the shock wave regime is approached, reduced spatial steps are required to avoid time points to "cross over," and the method can become notoriously slow. This paper analyses the fundamental difficulty with the common time base transformation, and provides an alternative that does not suffer from the mentioned slowdown. Numerical results will be shown to demonstrate that this alternative will allow much larger spatial steps without compromising the numerical accuracy.
Nonlinear behavior of a coupled multiscale material containing snapping acoustic metamaterial inclusions
Authors: Konarski Stephanie G. , Haberman Michael R. , Hamilton Mark F.
Published: October 2014

Snapping acoustic metamaterial (SAMM) inclusions are engineered sub-wavelength structures that exhibit regimes of both positive and negative stiffness. Snapping is defined as large, rapid deformations resulting from the application of an infinitesimal change in externally applied pressure. This snapping leads to a large hysteretic response at the inclusion scale and is thus of interest for enhancing absorption of energy in acoustic waves. The research presented here models the forced dynamics of a multiscale material consisting of SAMM inclusions embedded in a nearly incompressible viscoelastic matrix material to explore the influence of small-scale snapping on enhanced macroscopic absorption. The microscale is characterized by a single SAMM inclusion, while the macroscale is sufficiently large to encompass a low volume fraction of non-interacting SAMM inclusions within the nearly incompressible matrix. A model of the forced dynamical response of this heterogeneous material is achieved by coupling the two scales in time and space using a generalized Rayleigh-Plesset analysis, which has been adapted from the field of bubble dynamics. A loss factor for the heterogeneous medium is examined to characterize energy dissipation due to the forced behavior of these metamaterial inclusions. [Work supported by the ARL:UT McKinney Fellowship in Acoustics and Office of Naval Research.]
Correlation lengths in deconvolved cross-beamforming measurements of military jet noise
Authors: Harker Blaine M. , Gee Kent L. , Neilsen Tracianne B. , Wall Alan T. , James Michael M.
Published: October 2014

Beamforming algorithms have been applied in multiple contexts in aeroacoustic applications, but difficulty arises when applying these to the partially correlated and distributed sources found in jet noise. To measure and more accurately distinguish correlated sources, cross-beamforming methods are employed to incorporate correlation information. Deconvolution methods such as DAMAS-C, an extension of the deconvolution approach for the mapping of acoustic sources (DAMAS), remove array effects from cross-beamforming applications and further resolve beamforming results. While DAMAS-C results provide insight to correlation between sources, the extent to which these results relate to source correlation remains to be analyzed. Numerical simulations of sources with varying degrees of correlation are provided to benchmark the DAMAS-C results. Finally, correlation lengths are established for DAMAS-C results from measurements for full-scale military jet noise sources. [Work supported by ONR.]
Cross-language identification of non-native lexical tone
Authors: Alexander Jennifer , Wang Yue
Published: October 2014

We extend to lexical-tone systems a model of second-language perception, the Perceptual Assimilation Model (PAM) (Best & Tyler, 2007), to examine whether native-language lexical-tone experience influences identification of novel tone. Native listeners of Cantonese, Thai, Mandarin, and Yoruba hear six CV syllables, each produced with the three phonemic Yoruba tones (High-level/H, Mid-level/M, Low-level/L), presented randomly three times. In a 3-AFC task, participants indicate a syllable’s tone by selecting from a set of arrows the one that illustrates its pitch trajectory. Accuracy scores (proportion correct) were submitted to a two-way rANOVA with L1-Group (x4) as the between-subjects factor and Tone (x3) as the within-subjects factor. There was no main effect of Tone or Group. The Tone-by-Group interaction was significant (p = 0.031) but driven by one group: Thai listeners identified H and M more accurately than L (both p < 0.05), though L accuracy was above chance (59%; chance = 33.33%). Tone-error patterns indicate that Thai listeners primarily confused L with M (two-way L1-Group x Response-pattern rANOVA p < 0.05). Overall, despite their different tonal-L1 backgrounds, listeners performed comparably. As predicted by the PAM, listeners attended to gradient phonetic detail and acoustic cues relevant to L1 phoneme distinctions (F0 height/direction) in order to classify non-native contrasts. [NSF grant #0965227.]
The perception of English coda obstruents by Mandarin and Korean second language learners
Authors: Hao Yen-Chen , de Jong Kenneth
Published: October 2014

This study investigates the perception of English obstruents by learners whose native language is either Mandarin, which does not permit coda obstruents, or Korean, which neutralizes laryngeal and manner contrasts into voiceless stop codas. The stimuli are native productions of eight English obstruents /p b t d f v θ ð/ combined with the vowel /ɑ/ in different prosodic contexts. Forty-one Mandarin and 40 Korean speakers identified the consonant from the auditorily presented stimuli. The results show that the two groups do not differ in their accuracy in the onset position, indicating that they are comparable in their proficiency. However, the Mandarin speakers are more accurate in the coda position than the Koreans. When the fricatives and stops are analyzed separately, it shows that the two groups do not differ with fricatives, yet the Mandarin speakers are more accurate than the Koreans with stops. These findings suggest that having stop codas in their L1 does not necessarily facilitate Koreans’ acquisition of the L2 sounds. Despite their L1 differences, the two groups display very similar perceptual biases in their error patterns. However, not all of them can be explained by L1 transfer or universal markedness, suggesting other language-independent factors in L2 perception.
Amount of exposure and its effect on perception of second language front vowels in English
Authors: Jeske Andrew
Published: October 2014

Experience with a second language (L2) has been shown to positively affect learners’ perception of L2 sounds. However, few studies have focused on how the amount of L2 exposure in foreign language classrooms impacts perception of L2 sounds during the incipient stages of language learning in school-age children. To determine what effect, if any, the amount of L2 exposure has on perception, 64 students from a Spanish-English bilingual elementary school and 60 students from two non-bilingual elementary schools participated in an AX Categorical Discrimination task, which contained tokens of five English front vowels: /i ɪ e ɛ æ/. Results show that students from the bilingual school earned perception scores significantly higher than those earned by the students from the non-bilingual school (p = 0.002). However, an ANOVA found there to be no significant simple main effect for grade or significant correlation between grade level and school type. The bilingual school students perceived all within-category word pairings (e.g., bat-bat) significantly more accurately than the non-bilingual school students suggesting that increased, early exposure to an L2 may heighten one’s ability to disregard irrelevant, interpersonal phonetic differences and lead to a within-category perceptual advantage over those with less L2 exposure early on.
Effects of beliefs about first language orthography on second language vowel perception
Authors: Haslam Mara
Published: October 2014

Recent research has identified that L1 orthography can affect perception of vowels in a second language (e.g., Escudero and Wanrooij, 2010). The present study investigates the effect that participants' beliefs about orthography have on their ability to perceive vowels in a second language. English- and Polish-speaking learners of Swedish have to encounter some new vowel sounds and also the characters that are used to represent them, e.g., å, ä, and ö. New survey data of native speakers of English, Polish, and Swedish confirm that L1 English speakers see these characters like these as familiar letters with diacritics, while L1 Swedish and L1 Polish speakers tend to see these types of characters as different characters of the alphabet. These differing beliefs about orthography may cause English speakers to confuse the vowels represented in Swedish by the characters å, ä and ö with vowels represented by the characters a, a, and o, respectively, while Polish speakers would not be similarly affected. Results of a Swedish vowel perception study conducted with native speakers of English and Polish after exposure to Swedish words containing these characters will be presented. These results contribute to increasing knowledge about the relationship between L1 orthography and L2 phonology.
Generational difference in the perception of high-toned [il] in Seoul Korean
Authors: Cho Sunghye
Published: October 2014

A word-initial [il] is most frequently H-toned in Seoul Korean (SK) when it means one, out of three homophones, one, day, and work (Jun & Cha, 2011). However, Cho (2014) finds that 25% of teenagers always produce [il] with a H tone, regardless of its meaning. This paper examines how young SK speakers perceive the phenomenon. Thirty-seven SK speakers (aged 14–29) participated in two identification tasks, hearing only [il] in the first task and four [il]-initial minimal pairs in the second task. All target words were manipulated into five pitch levels with 30 Hz intervals. In the first task, the 20s group identified [il] as one 70% of the time at higher pitch levels, while the teenagers identified [il] as one about 50% of the time at all pitch levels. In the second task, the 20s group showed a categorical perception, identifying [il]-initial words as one only at higher pitch levels, while the teenagers did not. The results suggest that the teenagers are aware that some peers always produce [il] with a H tone. It explains that the 20s group could identify the meanings of [il] depending on the pitch, while the teenagers could not.
Language proficiency, context influence foreign-accent adaptation
Authors: Blanco Cynthia P. , Yi Hoyoung , Ferracane Elisa , Smiljanic Rajka
Published: October 2014

Listeners adapt quickly to changes in accent (Bradlow & Bent, 2003; Clarke & Garrett, 2004; inter alia). The cause of this brief delay may be due to the cost of processing accented speech, or may reflect a surprise effect associated with task expectations (Floccia et al., 2009). The present study examines a link between accent familiarity and processing delays with listeners who have varying degrees of familiarity with target languages: monolingual Texans with little or no formal exposure to Spanish, early Spanish-English bilinguals, and Korean learners of English. Participants heard four blocks of English sentences—Blocks 1 and 4 were produced by two native speakers of American English, and Blocks 2 and 3 were produced by native speakers of Spanish or Korean- and responded to written probe words. All listener groups responded more slowly after an accent change; however, the degree of delay varied with language proficiency. L1 Korean listeners were less delayed by Korean-accented speech than the other listeners, while changes to Spanish-accented speech were processed most slowly by Spanish-English bilinguals. The results suggest that adaptation to foreign-accented speech depends on language familiarity and task expectations. The processing delays are analyzed in light of intelligibility and accentedness measures.
Boundary enhanced coupling processes for rotated horizontal solid aluminum cylinders: Helical rays, synthetic aperture sonar images, and coupling conditions
Authors: La Follett Jon R. , Marston Philip L.
Published: October 2014

Experiments with solid aluminum cylinders placed near a flat free surface provide insight into scattering processes relevant to other flat reflecting boundaries [J. R. La Follett, K. L. Williams, and P. L. Marston, J. Acoust. Soc. Am. 130, 669–672 (2011); J. R. La Follett, Ph.D. thesis, WSU (2010)]. This presentation concerns the coupling to surface guided leaky Rayleigh waves that have been shown to contribute significantly to backscattering by solid metallic cylinders [K. Gipson and P. L. Marston, J. Acoust. Soc. Am. 106, 1673–1689 (1999)]. The emphasis here is on horizontal cylinders rotated about a vertical axis away from broadside viewed at grazing incidence. The range of rotation angles for which helical rays can contribute is limited in the free field by the cylinder’s length [F. J. Blonigen and P. L. Marston, J. Acoust. Soc. Am. 112, 528–536 (2002)]. Some examples of surface enhanced backscattering may be summarized as follows. In agreement with geometrical considerations, the angular range for coupling to helical rays may be significantly extended when a short cylinder is adjacent to a flat surface. In addition, the presence of a flat surface splits synthetic aperture sonar (SAS) image features from various guided wave mechanisms on rotated cylinders. [Work supported by ONR.]
TREX13 target experiments and case study: Comparison of aluminum cylinder data to combined finite element/physical acoustics modeling
Authors: Williams Kevin , Kargl Steven G. , Espana Aubrey L.
Published: October 2014

The apparatus and experimental procedure used during the target portion of TREX13 are described. A primary goal of the TREX13 target experiments was to test the high speed modeling methods developed and previously tested as part of efforts in more controlled environments where the sediment/water interface was flat. At issue is to what extent the simplified physics used in our models can predict the changes seen in acoustic templates (target strength versus angle and frequency) as a function of grazing angle, i.e., the Target-In-the-Environment-Response (TIER), for a target proud on an unprepared “natural” sand sediment interface. Data/model comparisons for a 3 ft. long, 1 ft. diameter cylinder are used as a case study. These comparisons indicate that much of the general TIER dependence is indeed captured and allows one to understand/predict geometries where the broadest band of TIER information can be obtained. This case study indicates the predictive utility of dissecting the target physics at the expense of making the model results “inexact” from a purely finite element, constitutive equation standpoint. [Work supported by ONR and SERDP.]
The physics of musical instruments with performance illustrations and a concert
Authors: Hansen Uwe J. , Kitterman Susan
Published: October 2014

Musical Instruments generally rely on the following elements for tone production: a power supply, an oscillator, a resonator, an amplifier, and a pitch control mechanism. The physical basis of these elements will be discussed for each instrument family with performance illustrations by the orchestra. Wave shapes and spectra will be shown for representative instruments. A pamphlet illustrating important elements for each instrument group will be distributed to the audience. The Science presentation with orchestral performance illustrations will be followed by a concert of the New World Youth Symphony Orchestra. This orchestra is one of three performing groups of the New World Youth Orchestras, an organization founded by Susan Kitterman in 1982. Members of the Symphony are chosen from the greater Indianapolis and Central Indiana area by audition.
Room acoustics analysis, recordings of real and simulated performances, and integration of an acoustic shell mock up with performers for evaluation of a choir shell design
Authors: Woolworth David S.
Published: October 2014

The current renovation of the 1883 Galloway Memorial Methodist Church required the repair and replacement of a number of room finishes, as well as resolution of acoustic problems related to their choir loft. This paper will present the various approaches used to determine the best course of action using primarily an in-situ analysis that includes construction mockups, simulated sources, and critical listening.
Real-time passive acoustic monitoring of baleen whales from autonomous platforms
Authors: Baumgartner Mark F.
Published: October 2014

An automated low-frequency detection and classification system (LFDCS) was developed for use with the digital acoustic monitoring (DMON) instrument to detect, classify, and report in near real time the calls of several baleen whale species, including fin, humpback, sei, bowhead, and North Atlantic right whales. The DMON/LFDCS has been integrated into the Slocum glider and APEX profiling float, and integration projects are currently underway for the Liquid Robotics wave glider and a moored buoy. In a recent evaluation study, two gliders reported over 25,000 acoustic detections attributed to fin, humpback, sei, and North Atlantic right whales over a 3-week period during late fall in the Gulf of Maine. The overall false detection rate for individual calls was 14%, and for right, humpback, and fin whales, false predictions of occurrence during 15-minute reporting periods were 5% or less. Agreement between acoustic detections and visual sightings from concurrent aerial and shipboard surveys was excellent (9 of 10 visual detections were accompanied by real-time acoustic detections of the same species by a nearby glider). We envision that this autonomous acoustic monitoring system will be a useful tool for both marine mammal research and mitigation applications.
High-frequency observations from mobile autonomous platforms
Authors: Klinck Holger , Matsumoto Haru , Fregosi Selene , Mellinger David K.
Published: October 2014

With increased human use of US coastal waters—including use by renewable energy activities such as the deployment and operation of wind, wave, and tidal energy converters—the issue of potential negative impacts on coastal ecosystems arises. Monitoring these areas efficiently for marine mammals is challenging. Recreational and commercial activities (e.g., fishing) can hinder long-term operation of fixed moored instruments. Additionally these shallow waters are often utilized by high-frequency cetaceans (e.g., harbor porpoises) which can only be acoustically detected over short distances of a few hundred meters. Mobile acoustic platforms are a useful tool to survey these areas of concern with increased temporal and spatial resolution compared to fixed systems and towed arrays. A commercially available acoustic recorder (type Song Meter SM2 + , Wildlife Acoustics, Inc.) featuring sampling rates up to 384 kHz was modified and implemented on an autonomous underwater vehicle (AUV) as well as an unmanned surface vehicle (USV) and tested in the field. Preliminary results indicate that these systems are effective at detecting the presence of high-frequency cetaceans such as harbor porpoises. Potential applications, limitations, and future directions of this technology will be discussed. [Project partly supported by ONR and NOAA.]
Slope inversion in a single-receiver context for three-dimensional wedge-like environments
Authors: Sturm Frédéric , Bonnel Julien
Published: October 2014

In a single-receiver context, time-frequency (TF) analysis can be used to analyze modal dispersion of low-frequency broadband sound pulses in shallow-water oceanic environments. In a previous work, TF analysis was used to study the propagation of low-frequency broadband pulses in three-dimensional (3-D) shallow-water wedge waveguides. Of particular interest is that TF analysis turns out to be a suitable tool to better understand, illustrate and visualize 3-D propagation effects for such wedge-like environments. In the present work, it is shown that TF analysis can also be used at the core of an inversion scheme to estimate the slope of the seabed in a same single hydrophone receiving configuration and for similar 3-D wedge-shaped waveguides. The inversion algorithm proposed, based on a masking process, focuses on specific parts of the TF domain where modal energy is concentrated. The criterion used to quantify the match between the received signal and the replicas by a fully 3-D parabolic equation code, is defined as the amount of measured time-frequency energy integrated inside the masks. Its maximization is obtained using an exhaustive search. The method is first benchmarked on numerical simulations and then successfully applied on experimental small-scale data.
Three-dimensional acoustics in basin scale propagation
Authors: Heaney Kevin D. , Campbell Richard L.
Published: October 2014

Long-range, basin-scale acoustic propagation has long been considered deep water and well represented by the two-dimensional numerical solution (range/depth) of wave equation. Ocean acoustic tomography has even recently been demonstrated to be insensitive to the three-dimensional affects of refraction and diffraction (Dushaw, JASA 2014). For frequencies below 50 Hz, where volume attenuation is negligible, the approximation that all propagation of significance is in the plane begins to break down. When examining very long-range propagation in situations where the source/receiver are not specifically selected for open water paths, 3D effects can dominate. Seamounts and bathymetry rises cause both refraction away from the shallowing seafloor and diffraction behind sharp edges. In this paper a set of recent observations, many from the International Monitoring System (IMS) of the United Nations Comprehensive Test Ban Treaty Organization (CTBTO) will be presented, demonstrating observations that are not well explained by Nx2D acoustic propagation. The Peregrine PE model, a recent recoding of RAM in C, has been extended to include 3D split-step Pade propagation and will be used to demonstrate how 3D acoustic propagation affects help explains some of the observations.
Acoustics research of propulsion systems
Authors: Gao Ximing , Houston Janice
Published: October 2014

The liftoff phase induces high acoustic loading over a broad frequency range for a launch vehicle. These external acoustic environments are used in the prediction of the internal vibration responses of the vehicle and components. Present liftoff vehicle acoustic environment prediction methods utilize stationary data from previously conducted hold-down tests to generate 1/3 octave band Sound Pressure Level (SPL) spectra. In an effort to update the accuracy and quality of liftoff acoustic loading predictions, non-stationary flight data from the Ares I-X were processed in PC-Signal in two flight phases: simulated hold-down and liftoff. In conjunction, the Prediction of Acoustic Vehicle Environments (PAVE) program was developed in MATLAB to allow for efficient predictions of sound pressure levels (SPLs) as a function of station number along the vehicle using semi-empirical methods. This consisted of generating the Dimensionless Spectrum Function (DSF) and Dimensionless Source Location (DSL) curves from the Ares I-X flight data. These are then used in the MATLAB program to generate the 1/3 octave band SPL spectra. Concluding results show major differences in SPLs between the hold-down test data and the processed Ares I-X flight data making the Ares I-X flight data more practical for future vehicle acoustic environment predictions.
Robust focusing in time-reversal mirror with a virtual source array
Authors: Byun Gi Hoon , Kim Jea Soo
Published: October 2014

The effectiveness of Time-Reversal (TR) focusing has been demonstrated in various fields of ocean acoustics. In TR focusing, a probe source is required for a coherent acoustic focus at the original probe source location. Recently, the need of a probe source has been partially relaxed by introduction of the concept of a Virtual Source Array (VSA) [S. C. Walker, Philippe Roux, and W. A. Kuperman, J. Acoust. Soc. Am. 125(6), 3828–3834 (2009)]. In this study, Adaptive Time-Reversal Mirror (ATRM) based on multiple constraint method [J. S. Kim, H. C. Song, and W. A. Kuperman, J. Acoust. Soc. Am. 109(5), 1817–1825 (2001)] and Singular Value Decomposition (SVD) method are applied to a VSA for robust focusing. The numerical simulation results are presented and discussed.
Ambient noise in the Arctic Ocean measured with a drifting vertical line array
Authors: Worcester Peter F. , Dzieciuch Matthew A. , Colosi John A. , Kemp John N.
Published: October 2014

In mid-April 2013, a Distributed Vertical Line Array (DVLA) with 22 hydrophone modules over a 600-m aperture immediately below the subsurface float was moored near the North Pole. The top ten hydrophones were spaced 14.5 m apart. The distances between the remaining hydrophones increased geometrically with depth. Temperature and salinity were measured by thermistors in the hydrophone modules and ten Sea-Bird MicroCATs. The mooring parted just above the anchor shortly after deployment and subsequently drifted slowly south toward Fram Strait until it was recovered in mid-September 2013. The DVLA recorded low-frequency ambient noise (1953.125 samples per second) for 108 minutes six days per week. Previously reported noise levels in the Arctic are highly variable, with periods of low noise when the wind is low and the ice is stable and periods of high noise associated with pressure ridging. The Arctic is currently undergoing dramatic changes, including reductions in the extent and thickness of the ice cover, the amount of multiyear ice, and the size of the ice keels. The ambient noise data collected as the DVLA drifted will test the hypothesis that these changes result in longer and more frequent periods of low noise conditions than experienced in the past.