bluuebunny/crossref_metadata_2025 huggingface dataset:
Insights into airplane overflight effects on bioacoustic activity levels from long-term acoustic monitoring
Authors: Parks Susan , Denes Samuel L. , Matthews Leanna P. , Varshney Pramod K. , Fristrup Kurt M.
Published: May 2016

The National Ecological Observatory Network (NEON) has established a framework through which a variety of environmental metrics will be continuously monitored measured for multiple decades at stations located across the United States. We describe a multiyear project that demonstrates the benefits of continuous acoustic monitoring at NEON sites. By utilizing long-term recordings, a wealth of data relating to species presence, animal behavior, and anthropogenic disturbance can be collected without the presence of human researchers. These recordings allow the measurement of contributions of anthropogenic activity to the cumulative sound energy at these locations and the response of all acoustically active species in the environment to individual events. Data from the NEON site at Harvard Forest, MA, were analyzed to assess the number of aircraft overflights detected at the location over the course of one year. The bioacoustic activity levels before, during and after were quantified for a subset of these events. Adding acoustics to the measurements already collected under NEON protocol can provide high-resolution information on the acoustic impact of human activities at these locations and allow for long-term monitoring with ground truth assessment of acoustic biodiversity. [Project supported by NSF award #1340669.]
Construction noise impact on wild birds
Authors: Bottalico Pasquale
Published: May 2016

Almost all bird species use acoustic signals to communicate between conspecifics or recognize biological signals, to mate, to detect the sounds of predators and/or prey, to perform mate selection, to defend their territory, and to perform social activities. Noise generated from human activities (in particular by infrastructure and construction sites) has a strong impact on the physiology and behavior of birds. In this work, a quantitative method for evaluating the impact of noise on wild birds is proposed. The method combines the results of previous studies that considered the effect of noise on birds and involved noise mapping evaluations. A forecast noise simulation was used to generate maps of (1) masking-annoyance areas and (2) potential density variation. The results permit a localization of the areas with greater impacts on birds. The mitigation interventions should be focused on these areas in order to balance bird habitat conservation and human use of land. The forecast results should be interpreted by ornithologists and merged with information collected during the monitoring of the areas and with the habitat suitability maps.
Ultrasound- and microbubble-enhanced chemotherapy for treating pancreatic cancer: A phase I clinical trial
Authors: Kotopoulis Spiros , Dimcevski Georg , Mc Cormack Emmet , Postema Michiel , Gjertsen Bjorn Tore , Gilja Odd Helge
Published: May 2016

Experimental research of ultrasound to induce or improve delivery has snowballed in the past decade. In our work, we investigate the use of low-intensity ultrasound in combination with clinically approved microbubbles to enhance the therapeutic efficacy of chemotherapy. Ten voluntary patients with locally advanced or metastatic pancreatic adenocarcinoma were consecutively recruited. Following standard chemotherapy protocol (intravenous infusion of gemcitabine over 30 min), a clinical ultrasound scanner was targeted at the largest slice of the tumour using modified non-linear contrast imaging settings (1.9 MHz center frequency, 0.27 MPa peak-negative pressure), and SonoVue® was injected intravenously. Ultrasound and microbubble treatment duration was 31.5 min. The combined therapy did not induce any additional toxicity or increase side effect frequency when compared to chemotherapy alone. Combination treated patients were able to tolerate an increased amount treatment cycles when compare historical controls (n = 63); average of 8.3±6.0 cycles, versus 13.8±5.6 cycles. The median survival also increased from 7.0 months to 17.6 months (p = 0.0044). In addition, five patients showed a primary tumor diameter decrease. Combined treatment of ultrasound, microbubbles, and gemcitabine does not increase side effects and may have the potential to increase the therapeutic efficacy of chemotherapy in patients with pancreatic adenocarcinoma.
Ultrasound-mediated delivery of gadolinium and fluorescent-labeled liposomes through the blood-brain barrier
Authors: Aryal Muna , Papademetriou Jason , Zhang Yong-Zhi , Power Chanikarn , McDannold Nathan , Porter Tyrone
Published: May 2016

The main objective of this study was to examine liposome extravasation across the BBB as a function of size after disruption via ultrasound and microbubbles. The liposomes were labeled with gadolinium (Gd) and fluorophore, thus enabling detection of extravasated liposomes via MRI in vivo and fluorescence methods in tissue, respectively. Liposomes labeled with gadolinium and fluorophore were prepared using lipid film hydration and extrusion to two different sizes (~80 nm and ~140 nm). Animals were divided into two groups based on the use of particle sizes. FUS–BBB disruption was produced in one hemisphere in 10 mice. Particles were injected before sonication. Sonications (0.69 MHz at 0.68 MPa) were performed in two locations combine with Definity (10 μl/kg). Acoustic emissions were recorded during FUS. T1 & T2*-weighted MRI were used to confirm Gd leakage and damage detection respectively. Mice were euthanized 5–24 h after FUS and post-process for fluorescence measurement. In sonicated area, Gd-leakage was detected in both groups at 5–24 after FUS but not on non-sonicated area. Fluorescence measurements from brain tissue homogenates suggest enhanced accumulation of liposomes in FUS versus non-FUS brain regions. These findings reveal that liposomes were able to extravasate via FUS-BBB disruption.
Thrombolytic efficacy of echogenic liposomes that co-encapsulate rt-PA and octafluoropropane gas
Authors: Shekhar Himanshu , Huang Shenwen , Peng Tao , Klegerman Melvin E. , Huang Shao- L. , McPherson David D. , Holland Christy K.
Published: May 2016

Echogenic liposomes loaded with recombinant tissue-type plasminogen activator, rt-PA (tELIP), are under development for treatment of thrombo-occlusive disease. However, tELIP filled with air nucleate low stable cavitation activity when exposed to 120-kHz ultrasound, which limits the thrombolytic efficacy. We hypothesize that encapsulating octafluoropropane (OFP) gas in ELIP (OFP-tELIP) will enhance ultrasound-mediated stable cavitation activity and thrombolytic efficacy. A spectrophotometric method was used to assess the enzymatic activity of the rt-PA associated with OFP-tELIP. An in vitro flow model equipped with a time-lapse microscopy system was employed to observe human whole blood clots exposed to fresh-frozen plasma, rt-PA (0, 0.32, 1.58, and 3.15 μg/mL), and OFP-tELIP with and without ultrasound (120 kHz, 0.44 MPa peak-to-peak pressure). Ultraharmonic emissions indicating stable cavitation were measured using a passive cavitation detector. Sustained ultraharmonic activity was nucleated from OFP-tELIP when exposed to ultrasound, resulting in enhanced thrombolytic efficacy at an rt-PA concentration of 1.58 μg/mL. The results of this study demonstrate the advantages of encapsulating OFP within tELIP for use as a sonothrombolysis agent.
Shape mode stability of lipid-coated ultrasound contrast agent microbubbles
Authors: Brlansky John T. , Calvisi Michael L.
Published: May 2016

Ultrasound contrast agents (UCAs) are shell encapsulated microbubbles developed originally for ultrasound imaging enhancement. More recently, UCAs are being exploited for therapeutic applications such as drug and gene delivery. Ultrasound transducer pulses can induce spherical (radial) UCA oscillations, translation, and nonspherical shape oscillations, the latter of which can lead to breakup. Breakup can facilitate drug or gene delivery, but should be minimized for imaging purposes to increase residence time and maximize diagnostic effect. Therefore, an understanding of the interplay between the acoustic driving and shape mode stability of UCAs is important for both diagnostic and therapeutic applications. The present work couples a radial model of a lipid-coated microbubble with a model for bubble translation and nonspherical shape oscillation to predict shape mode stability for ultrasound driving frequencies and pressure amplitudes of clinical interest. In addition, calculations of the stability of individual shape modes, residence time, maximum radius, and translation are provided with respect to acoustic driving parameters and compared to an unshelled bubble. The effects of shell elasticity, shell viscosity, and initial radius on stability are investigated. The results show greater stability at higher values of shell elasticity and viscosity and at smaller radius, and provide guidance for optimizing shell design and ultrasound driving parameters with respect to shape stability.
A case study approach involving string harmonics to reinforce concepts of standing waves, superposition, and musical intervals... as well as the scientific process
Authors: Piacsek Andrew A.
Published: May 2016

A combined classroom/lab activity is described that employs a modified Interrupted Case Study approach to reinforce concepts of standing waves, superposition, and musical intervals. Students work cooperatively, with guidance from the instructor, to investigate the behavior of a plucked string. The activity is structured as a sequence of tasks that encapsulate the scientific process, requiring the application of critical thinking skills and knowledge from earlier classes. Students working in small groups propose a hypothesis about the behavior of a string that is plucked, drawing upon previous studies of superposition and standing wave behavior in a driven string. After a class discussion, one hypothesis is chosen as the basis for further inquiry. Each group then formulates specific testable predictions, with the constraint that only a mounted string (sonometer), finger, and ears be used in any experiment. After discussion, the class chooses a subset of these predictions to test. Groups formulate a detailed procedure (generally involving creating harmonics on the string), carry out the experiment, and interpret their results. Conclusions are shared among the class.
Acoustic travel-time tomography of the atmospheric surface layer at the Boulder Atmospheric Observatory
Authors: Ostashev Vladimir E. , Vecherin Sergey N. , Wilson D. K. , Bedard Alfred J.
Published: May 2016

Acoustic tomography of the atmospheric surface layer (ASL) is based on travel-time measurements between speakers and microphones in a spatial array, which are arranged so as to create propagation paths through the region to be sampled. Then, the temperature and wind velocity fields inside the tomographic region are reconstructed by inverting the travel times. Tomography has certain advantages over conventional point measurements, such as spatial averaging and a quadratic growth of the observations relative to the number of sensors. An array built at the Boulder Atmospheric Observatory (BAO) enables horizontal-slice tomography of the ASL at a height of 8 m above the ground, in an 80 m x 80 m region. The instrumentation and principle of operation of the BAO tomography array are explained. Inverse algorithms for reconstruction of the temperature and wind velocity fields from the travel times are reviewed. Results in numerical simulations of the BAO tomography array and reconstruction of turbulence fields in tomography experiments are presented. Acoustic tomography of the atmosphere can also be performed at other spatial scales, ranging from a size of an ultrasonic anemometer/thermometer to the height of the atmospheric boundary layer and even in the stratosphere and thermosphere.
Unified analysis of accuracy and reaction times via models of decision making
Authors: Mathias Samuel R.
Published: May 2016

“Sequential-sampling” models aim to characterize decision making during forced-choice experiments. These models decompose the decision process into its constituent elements, and can explain not only the probabilities with which subjects make each possible response, but the full distributions of reaction times associated with each of the response alternatives. Thus, such models provide a powerful framework for the analysis of behavioral data. However, despite being extremely popular in the cognitive sciences, they are almost never used in psychoacoustics. By way of example experiments, I will discuss how to fit these kinds of models to psychoacoustical data, using traditional maximum likelihood and hierarchical Bayesian inference, and how to interpret their results in terms of the underlying decision processes.
Advances in quantifying listening effort: Growth curve analyses of pupillometry data
Authors: Kuchinsky Stefanie E. , Dubno Judy R. , Eckert Mark A.
Published: May 2016

Understanding speech in background noise often requires substantial mental effort, especially in adverse signal-to-noise ratios (SNRs) and for older adults with hearing loss. Pupillometry has been used to index listening-related effort, because pupil dilation is an autonomic response that is modulated by changes in cognitive demands, such as when recognizing speech in decreasing SNRs. This presentation will focus on our approach to quantifying the pupil response through growth curve analysis (GCA), a multilevel modeling technique in which orthogonalized polynomials are fit to time series data to capture its shape. We will provide an overview of our pupillometry research that employed GCA to characterize (1) changes in the pupil response across varying listening conditions and (2) individual differences in the pupil response among older adults with hearing loss. Discussion will include statistical advantages of this approach compared to commonly used peak-picking analyses, implementation of GCA in R, and the theoretical interpretation of model results. We will conclude by demonstrating that GCA results can be linked to functional neuroimaging data in order to further our understanding of the neural mechanisms that underlie listening effort. [Work supported, in part, by NIH/NIDCD and a Hearing Health Foundation Centurion Clinical Research Award.]
Individual differences in hearing-impaired data: Stats, troubles, and approaches
Authors: Verhulst Sarah
Published: May 2016

Individual differences in hearing ability might be dominated by subcomponents of hearing loss, e.g., cochlear gain loss, cochlear neuropathy, temporal coding deficits in low/high frequency regions, or combinations of these components. Unfortunately, we can only rely on indirect and hypothesis-driven objective (e.g., OAE/ABR/EFR) and psychoacoustic threshold metrics that aim to quantify these subcomponents of hearing loss, complicating a straightforward explanation of study results. Because correlations statistics often rely on small listener groups in which each data point could have resulted from different SNRs, metric-specific variability, it is not always clear which correlations are significant and meaningful. Additionally, multiple measures provide a multitude of correlations that should all support the common underlying hypothesis before conclusions can be drawn. In this tutorial, I provide some examples and approaches to more (and less) meaningful correlations based on recently collected objective and psychoacoustic measures in a group of normal and hearing-impaired listeners. Finally, I will introduce how computational model approaches might direct the interpretation of experimental results when several interacting sources of hearing impairment impact outcome measures unexpectedly.
Anticlastic bending of rectangular plates and inference of Poisson’s ratio
Authors: Shepherd Micah R. , Hambric Stephen A.
Published: May 2016

Elastic plates will exhibit anticlastic behavior due to the Poisson effect. This effect is often overlooked in the analysis of rectangular plates. However, the effect can be substantial for when the boundary conditions are free, causing nodal lines of certain mode shapes to be curved rather than straight. A rectangular plate finite element model comprised of quadratic solid elements was exercised to determine the dependency of the anticlastic bending on plate thickness, aspect ratio, and elastic modulus. A metric to quantify anticlastic behavior was then developed for both bending modes and axial modes. Finally, experimentally obtained mode shapes were used to infer the Poisson’s ratio of a rectangular section of hard foam using the derived dependencies.
Partial differential equation-constrained optimization framework for inverse design of acoustic damping layers
Authors: Sanders Clay , Aquino Wilkins , Walsh Timothy F.
Published: May 2016

We present a partial differential equation-constrained framework for the design of viscoelastic damping layer assemblies in one and two dimensions. Viscoelastic foams’ responses to loads not only provide stiffness and damping, but also vary with frequency. In a finite-element formulation, a viscoelastic solid’s structural stiffness is determined by its complex valued shear and bulk moduli. By optimally selecting the moduli values of a layered assembly, we demonstrate an effective design of graded foam that minimizes its acoustic scattering in a fluid waveguide. We define a cost functional based on the scattered field from the acoustic-structural interaction of the viscoelastic inclusion in a fluid medium. In the optimization calculations, the complex valued moduli were modified to minimize the objective functional representing the scattered field energy. Models used in numerical simulations featured circular inclusions with distinct concentric rings. This talk will focus on the convergence of optimal designs and effects of frequency and solver algorithms. Numerical results suggest the potential for optimally designed viscoelastic foams to minimize acoustic scattering. [Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL850000.]
Research on detection technology for aligned array acoustic sonde of acoustic logging tool
Authors: Liu Dong , Ju Xiaodong , Lu Junqiang , Men Baiyong , Yu Zhijun
Published: May 2016

While aligned array transmitting and receiving acoustic sonde helps in improving the acquisition accuracy and 3D resolution of signals, it also increases the difficulty of detecting and maintaining the sound sonde. A debugging framework based on embedded ARM7&uclinux platform is built; a functional board is designed to simulate the process of transmitting and receiving acoustic sonde, and an evaluation method on the validity and consistency of aligned array probes is proposed. In this design, ARM front terminal is interconnected with host computer through network, and test function board communicates with front terminal through an imitation PC104 bus. The test function board comprises a signal sampling and processing module and an analog signal transmitting module. When debugging the transmitting acoustic sonde, the sampling and processing module with built-in receiver simulates the receiving acoustic sonde, processes the signal by sampling, amplifying, filtering, and analog-digital converting, and then uploads to the host computer. When debugging the receiving acoustic sonde, the analog signal transmitting module, based on DDS technology, simulates periodical sound fields with power horn, which include imitation strata longitudinal wave, shear wave, and stoneley wave. The experiment shows that this design would reduce failure rate of acoustic sonde and improve work efficiency.
Method for effective implementation of an acoustic based Hostile Fire Detection System on moving vehicles
Authors: Prather Wayne E. , Frazier William G.
Published: May 2016

Due to background noise issues, effective implementation of an acoustic array as part of a Hostile Fire Detection System on moving vehicles has been a significant challenge to date. A new method utilizing both software and hardware design parameters has been developed and successfully demonstrated to be very effective at high speeds on various vehicles. This method has been shown to be effective against both flow based noise sources and acoustic wave based noise sources in low signal to noise ratio conditions. The technology will be discussed and results from measurements utilizing conformally mounted acoustic sensors on moving ground vehicles will be shown.
Deficits in the sensitivity to pitch sweeps by school-aged children wearing cochlear implants
Authors: Deroche Mickael L. , Kulkarni Aditya M. , Christensen Julie A. , Limb Charles J. , Chatterjee Monita
Published: May 2016

Sensitivity to static changes in pitch has been shown to be poorer in school-aged children wearing cochlear implants (CIs) than children with normal hearing (NH), but it is unclear whether this is also the case for dynamic changes. Yet, dynamically changing pitch has considerable ecological relevance in terms of natural speech, particularly aspects such as intonation, emotion, or lexical tone information. This study examined children and adults, with NH or wearing a CI using clinically assigned settings with envelope-based coding strategies. Percent correct was measured in one- or three-interval two-alternative forced choice tasks, for the direction or discrimination of harmonic complexes based on a linearly rising or falling fundamental frequency. Sweep rates were adjusted per subject, in a logarithmic scale, so as to cover the full extent of the psychometric function. Data for up- and down-sweeps were fitted separately, using a maximum-likelihood technique. Hits and false alarms were then converted into d’ and beta values, from which a threshold was extracted at a d’ of 0.77. Thresholds were very consistent between the two tasks and considerably higher (worse) for CI listeners than for their NH peers. Thresholds were also higher for children than adults. Factors such as age at implantation, age at profound hearing loss, and duration of CI experience did not play any major role in this sensitivity. Sweep direction thresholds held the most predictive power for performance in tasks related to speech prosody.
Effects of interleaved noise on speech recognition in children
Authors: Youngdahl Carla L. , Yoho Sarah E. , Holt Rachael F. , Apoux Frederic , Healy Eric w.
Published: May 2016

Normal-hearing adults can isolate frequency regions containing clean speech from surrounding regions containing noise. However, children have been shown to integrate information over a large number of auditory filters, and so they may not be able to isolate frequency regions as well. To assess children’s level of auditory filter independence, words were filtered into 30 contiguous 1-ERB-width bands. Speech was presented in every other band, for a total of 15 speech bands. Speech-shaped noise was then added to: all 30 contiguous bands, the 15 bands not containing speech (OFF), or the 15 bands containing speech (ON). Three age groups were tested: 10 adults, 9 older children (6–7 yr old), and 9 younger children (5 yr old). Consistent with previous findings involving consonant recognition, adults displayed large performance differences between off- and on-frequency noise (OFF vs. ON). The 6- to 7-yr-old group performed similarly to adults. In contrast, the 5-yr-old group displayed equivalent performance in the OFF and ON conditions. This indicates that, for these younger children, even noise that was mostly non-overlapping in frequency interfered with speech recognition as much as noise that was on frequency. [Work supported by NIH.]
Audiovisual integration in fricative production and perception by nonnative speakers
Authors: Harrison Margaret , Lee Chao-Yang , Wiener Seth
Published: May 2016

Lip rounding enhances the acoustic contrast between /s/ and /ʃ/ in English. For speakers of languages without this phonemic distinction, to what degree does lip rounding affect the production and perception of these fricatives? Is visual awareness of lip rounding associated with audiovisual integration commonly observed in the McGurk effect? How does this performance develop as a function of exposure to English? Fourteen learners of English participated in three tasks. First, participants read a list of /s/-/ʃ/ minimal pairs. The spectral center of gravity was measured to examine learners’ production of the contrast. Second, participants watched/listened to the same words produced by a native English speaker in four presentation formats: audio only, audiovisual-congruent, audiovisual-incongruent (e.g., an audio /s/ paired with a visual /ʃ/), and visual only. Finally, participants listened to four stop-vowel syllables paired with either congruent or incongruent videos. Two experimental sessions were conducted to examine the development of the performance. Preliminary results showed identification accuracy of /s/, compared to /ʃ/, was affected to a greater extent by presentation format. Response to /s/ was slower in the first session, but was comparable to /ʃ/ in the second session.
Visual and auditory native language interference in perceptual learning of non-native speech sounds
Authors: Fuhrmeister Pamela , Earle F. Sayako , Rueckl Jay , Myers Emily
Published: May 2016

Learning speech sounds in a second language is challenging for adults, especially when non-native phonemes are perceptually similar to those in the native language. Results from Earle and Myers (2015) suggest that auditory exposure to native language tokens that are perceptually similar to a learned non-native phonetic contrast attenuate sleep-mediated gains in perceptual learning. The present study seeks to determine whether activating abstract phonetic category representations through visual input will produce a similar interference effect on a learned non-native phonetic contrast. To test this, we trained participants to identify the Hindi dental and retroflex contrast and reassessed their performance following a period of sleep. Immediately after training, participants were exposed to interference tokens through a pseudohomophone judgment task, in which they were asked to decide if a string of letters spelled out a real word when read aloud (e.g., “drane” = drain). One group read words with /d/-initial tokens (perceptually similar to the learned contrast) and another read /b/-initial tokens (perceptually dissimilar). The effect of visual interference on perceptual performance differed from the effects observed with auditory interference. These results suggest that different modalities of language input differentially interfere with perceptual learning of non-native speech sounds.
The effect of visual information on non-native speakers' perception of Cantonese tones
Authors: Chen Yan
Published: May 2016

This study examines the effect of tone marks on the perception of 5 difficult Cantonese tone pairs that have high perceptual similarity: high-rising (25) versus mid-rising (23), mid-level (33) versus low-level (22/11), low-falling (21) versus low-rising (23), low-falling (21) versus low-level (22/11), and low-rising (23) versus low-level(22/11). Native speakers of American English and native speakers of Mandarin participated in a categorial AXB pre-test, a categorial AX training, and a categorial AXB post-test. Half of the subjects received iconic symbols (㐂 ⌉ for high-rising (25), ㌷ for mid-level (33), 㐂 for low-falling (21), 㐂 ㌷ for low-rising (23), and 㐂 for low-level (22/11)) as feedback in the training (Auditory-Visual training group) while the other half did not (Auditory). Preliminary results showed that both language groups improved their discrimination of all the tone pairs and that Mandarin speakers received higher percent response than English speakers in the post-test. AV subjects and A subjects, regardless of language groups, did not differ significantly in percent correct response in the post-test. Reaction time data suggested that AV subjects responded faster on the pair high-rising (25) versus mid-rising (23) than A subjects, regardless of language groups, and that Mandarin speakers responded faster than English speakers in the post-test.
Discriminability of non-native tonal contours in low-pass filtered speech
Authors: Morrill Tuuli , Gao Zhiyan
Published: May 2016

Native speakers of a language are able to easily detect non-native “accents”—usually a perceived accent is attributed to phonemic- and phonetic- level information. However, a growing body of work suggests that non-native speakers also exhibit differences from native speakers at the prosodic level. Differences are exhibited in the placement of lexical stress and phrasal accents, as well as the acoustic cues used in prominence production; prosodic differences in production appear to pattern in (native)-language-specific ways (Morrill, ICPhS Proceedings, 2015). In this experiment, we ask (1) whether differences in the realization of tonal contours are perceived by listeners, and (2) whether perceptual discriminability is patterning according to speakers’ native language. Participants listened to low-pass filtered phrases from the Stella passage recordings on the GMU Speech Accent Archive—produced by native speakers of English, Mandarin, Korean, Arabic, and Turkish—and judged whether speakers were saying the same thing. Results indicate that participants were less likely to rate two phrases as the same (even when they were) if they had been produced by speakers of different native languages. Patterns of discriminability across language pairings are attributed to differences in the number and timing of tonal events (e.g., pitch accents).
Adaptation to accent is proportionate to the prevalence of accented speech
Authors: Lehet Matt , Holt Lori L.
Published: May 2016

Listeners rapidly reweight the mapping of acoustic cues to speech categories in response to abrupt introductions of accented speech. For instance, when encountering an accent that reverses the typical correlation of acoustic cues to speech category membership, listeners rapidly down-weight reliance on secondary cues [Idemaru and Holt, 2011; 2014; Liu and Holt 2015]. Here, we examined the impact of experiencing mixtures of typical and accented speech in evoking cue down-weighting to test how much information the system requires to adapt. Listeners recognized words as beer versus pier across 41 blocks of 20 trials. In the first block, participants exclusively encountered tokens with the canonical English relationship between fundamental frequency (F0) and voice onset time (VOT); low F0 frequencies were associated with short VOT durations whereas high F0 frequencies were associated with long VOT durations. In subsequent blocks, the ratio of canonical to accented tokens (for which the F0/VOT correlation was reversed) was changed by 5% per block until participants experienced exclusively accented speech. Canonical tokens were then reintroduced incrementally, until participants exclusively heard canonical speech. Reliance on F0 for word recognition linearly decreased as the proportion of accented speech increased. Implications for models of the speech perception system are discussed.
Extrapolation of measured correlation replica fields in passive acoustic source localization
Authors: Verlinden Christopher M. , Sarkar J , Sabra K G. , Kuperman W A.
Published: May 2016

A method of localizing unknown acoustic sources using data derived replicas from ships of opportunity has been previously reported (Verlinden, 2015). The method is capable of localizing sources in positions where data derived replicas are available, such as locations previously transited by ships, tracked using the Automatic Identification System (AIS). Here, we present an extension of this localization method to regions where data derived replicas are not available by extrapolating the measured replicas onto a more extensive grid. This new augmentation provides the additional opportunity for continuous tracking.
Compressive acoustic sound speed profile estimation using wavelets
Authors: Bianco Michael J. , Niu Haiqiang , Gerstoft Peter
Published: May 2016

Estimation of ocean acoustic sound speed profiles (SSPs) requires inversion of acoustic data with limited observations. Inversion for true ocean SSP structure is a nonlinear, underdetermined problem that requires regularization to ensure physically realistic solutions. Traditional regularization, which minimizes the energy of best-fit solutions, requires undersampling of true SSPs or using few shape functions. This gives low resolution SSP estimates which can affect the accuracy of other parameters in geoacoustic inversion. Compressive sensing (CS) reliably estimates signal parameters for certain highly underdetermined linear problems provided the signal can be “compressed:” represented in a sparse domain where few non-zero coefficients (out of many) explain the observations. Here, it is shown that ocean SSPs can be compressed using dictionaries of wavelets, empirical orthogonal functions, and other shape functions given a priori environmental statistics. Shape dictionaries are sought which represent SSPs using the fewest coefficients. These optimal dictionaries are used with CS to estimate SSPs by inverting a linearized normal mode model. It is shown that range-independent ocean SSPs are estimated robustly and in high resolution using CS.
Design of Gran Teatro Nacional in Lima—A world class opera house in South America
Authors: Nepomuceno José A. , Gaspar Julio
Published: May 2016

The design of Gran Teatro Nacional in Lima, Peru, started in 2009 as very special task. Peru needed a venue with world-class standards to host local and international events of opera, concerts, and ballet. The theater has a built area of about 26 000 m2 with 1500 seats capacity. It has a fully equipped fly tower with motorized winches, an 11 m tall acoustical shell, 4 double deck stage lifts, 2 orchestra lifts, and a pit for 100 players. The equipment complies with the most restrictive European standards. The acoustics oriented the design, from room shaping to its volume, from materiality to seats selection. The acoustical consultants assumed modified horseshoe plan to improved intimacy and three tier levels. The hall has two reverberation chambers and several acoustical banners to provide variability in the acoustical response of the hall. Computer modeling and physical model supported the design. Since the Gala Opening in 2012 the theater has been getting remarkable reviews from conductors, international orchestras, and artists in general. The theater complied with the mission of bringing a world class performing art center to Peru. The paper provides the history of the project, architectural, and construction details and acoustical data.
Bowhead whale localization and environmental inversion using asynchronous hydrophones
Authors: Warner Graham A. , Dosso Stan E. , Hannay David E. , Dettmer Jan
Published: May 2016

This paper estimates bowhead whale locations and environmental properties using Bayesian inversion of the modal dispersion of whale calls recorded on asynchronous recorders in the shallow waters of the northeastern Chukchi Sea, Alaska. Bowhead calls were recorded on a Y-shaped cluster of seven autonomous ocean-bottom hydrophones, separated by up to 9.2 km. We use a warping time-frequency analysis to obtain frequency-dependent relative mode arrival times for nine frequency-modulated whale calls. Trans-dimensional inversion is applied to invert mode arrival times for the whale location, water sound-speed profile, subbottom layering and geoacoustic parameters, source instantaneous frequency (IF), relative recorder clock drifts, and residual error standard deviation, all with estimated uncertainties. Joint inversion of multiple calls is found to substantially reduce uncertainties on whale location, source IF, and clock drifts. Estimated whale location uncertainties are 30–160 m and clock drift uncertainties are 3–26 ms. The prior and posterior probability densities for environmental parameters are used to quantify transmission loss uncertainties corresponding to different levels of environmental knowledge, with applications to computing marine-mammal sound exposure levels.
Broadband active acoustics for synoptic studies of marine ecosystem
Authors: Lavery Andone C. , Stanton Timothy K.
Published: May 2016

Marine ecosystems host a wide variety of organisms spanning many trophic levels, ranging from the smallest planktonic organisms that comprise the base of the marine food web, to large apex predator fishes, marine mammals, such as whales, and sea birds. Active acoustical systems that span a wide range of frequencies are required to quantitatively characterize these organisms, their distribution and abundance. In this presentation, we discuss the development and use of broadband acoustic systems that are optimized for studies of fish and zooplankton through use of spectral classification methods. For swimbladder-bearing fish, a low-frequency (1–6 kHz) broadband system is described that classifies fish according to the resonance of its swimbladder. For zooplankton, a high frequency (25–600 kHz) broadband system is described that classifies zooplankton either according the resonance of their gas (gas-bearing zooplankton only) or according to the transition between the Rayleigh and geometric scattering region (non-gaseous zooplankton). Because of the resolving power of the broadband signals, the echoes also tend to be non-Rayleigh, which has additional classification information. Applications of the spectral and statistical broadband acoustics methods to ecosystem research are given. [Work supported by the Office of Naval Research and the Woods Hole Oceanographic Institution.]
Fully utilizing the acoustic record for biological monitoring and ecological applications
Authors: Horne John K. , Hytnen Ross , Maxwell Shari , Ham Kenneth , Maxwell Adam , Condiotty Jeff
Published: May 2016

Increasing demands to monitor marine ecosystems amplifies the need for efficient and effective characterization of organism abundances and distributions. Monitoring, processing, and archiving acoustic data may also be required in near-real-time when documenting environmental change or reporting impacts when meeting regulatory requirements. The Nekton Interactive Monitoring System (NIMS) is designed to address four challenges of ocean observation and monitoring: animal tracking, distribution characterization, regulatory thresholds, and data volume reduction. A Kalman filter is used to identify and link candidate targets into tracks. Backscatter measures are characterized using a suite of metrics (Sv, inertia, dispersion, Aggregation Index, evenness, % occupied) to quantify vertical distributions of pelagic organisms. If tracks cross pre-set exclusion ranges or regulatory thresholds of metrics are exceeded, then notifications are sent to trigger operational modification or mitigation. Kongsberg M3 sonar raw data acquisition rates of 11 Mb per second are reduced to 11 Mb per hour data storage, a 4 order of magnitude data savings. NIMS middleware can be deployed autonomously with instrument packages, remotely to telemeter data, network connected for real time monitoring, or used to process archived data. Example applications include ocean observatories and marine renewable energy environmental monitoring.
Bioacoustic absorption spectroscopy: An acoustical oceanography method for the study of marine ecosystems
Authors: Diachok Orest
Published: May 2016

Recent experiments have demonstrated the potential of the Bioacoustic Absorption Spectroscopy (BAS) method for measuring number densities vs. fish length and species when combined with concurrent trawling data, and studying vertical migrations and schooling behavior of fish at mesoscale dimensions.. Measurements of transmission loss between moving or stationary broadband source(s) and vertical array(s) of hydrophones separated by several (up to ~10) km permits inference of absorption coefficients versus frequency and depth, and association of absorption lines with the resonance frequencies of fish swim bladders. BAS is environmentally friendly, as it can be implemented with source levels < 170 dB, is sensitive to fish throughout the water column, including near boundaries, and is not affected by avoidance. The most significant results of BAS experiments will be reviewed, and possible approaches for use of the BAS method for routine scientific study and fisheries surveys of marine ecosystems will be considered.
Prediction of multivalued waveforms in media with power-law attenuation
Authors: Cormack John M. , Hamilton Mark F.
Published: May 2016

The lossless Burgers equation predicts a multivalued waveform beyond a certain propagation distance. Inclusion of thermoviscous attenuation, which increases as frequency squared, prevents the occurrence of multivalued waveforms. The same is true for any attenuation law that is proportional to frequency raised to an exponent greater than unity. For exponents less than unity the situation is less clear. For example, when attenuation is constant with frequency (exponent equal zero) there is a critical value of the attenuation coefficient below which a multivalued waveform is predicted and above which it is not. To investigate the prediction of multivalued waveforms for power-law attenuation with exponents between zero and unity, a Burgers equation with the loss term expressed as a fractional derivative is used [Prieur and Holm, J. Acoust. Soc. Am. 130, 1125 (2011)]. Transformation of the equation into intrinsic coordinates following Hammerton and Crighton [J. Fluid Mech. 252, 585 (1993)] permits numerical solutions to be obtained that are used to determine the parameter space in which initially sinusoidal plane waves are predicted to evolve into multivalued waveforms for power-law attenuation with exponents less than unity. [Work supported by the ARL:UT McKinney Fellowship in Acoustics.]
Detecting changes in the cytoskeletal structure of malignant pancreatic cells using high-frequency ultrasound
Authors: Carter Caitlin , Behan Ashley , Sanjinez Dolly A. , LaFond Amy A. , Doyle Timothy E.
Published: May 2016

Traditional classification of breast cancer subtype is determined based on protein expression and genetic profile. Determining the molecular subtype of breast cancer can make prognosis more accurate and help to personalize treatment. More aggressive subtypes of breast cancer, such as basal-like and Her2 + , have mutations that alter the protein regulation of the cell cytoskeleton. These cytoskeleton modulations can enable the cell to become more mobile and metastasize to other parts of the body. High-frequency ultrasound (10–100 MHz) has previously been studied for the real-time diagnosis of malignant tissue in breast conservation surgery. High-frequency ultrasound also has the potential of determining the molecular subtype of breast cancer. The objective of this work was to determine if chemically induced changes in the cytoskeleton of cancer cell lines are able to be detected using high-frequency ultrasound. Cell cultures of a human pancreatic carcinoma cell line (panc-1) were grown in monolayers and then treated with sphingosylphosphorylcholine (SPC), a bioactive lipid that rearranges the keratin components of the cytoskeleton. Pulse-echo measurements of the cultures were taken over a period of one hour. The results of this work demonstrate that high-frequency ultrasonic spectra are sensitive to the cytoskeleton changes induced by SPC.
The impact of William J. Strong on the acoustics program at Brigham Young University
Authors: Sommerfeldt Scott D.
Published: May 2016

The early years of acoustics at Brigham Young University (BYU) include names such as Eyring, Fletcher, and Knudsen. However, for nearly 35 years, Bill Strong was the face of acoustics at BYU. As a faculty member, he contributed significantly to the maintenance and strengthening of acoustics at BYU, influencing many lives along the way. One of those lives influenced was the author. Beyond his positive influence in shaping many lives, Bill also contributed significantly to acoustics research throughout his career. Much of his work centered on the acoustics of speech and music. His text, Music, Speech, Audio, has been used for decades to introduce many students to the field of acoustics and has been the text for a popular course on the subject at BYU. This presentation will overview some of Bill’s many contributions, both in acoustics and otherwise, with an emphasis on some of the work carried out by the author and Bill on the acoustics of the clarinet. That work includes a study of the interactions associated with the combined player-clarinet system, as well as an investigation of the directivity of the sound radiated from the clarinet.
From musical acoustics to noise control
Authors: Copley David C.
Published: May 2016

This presentation is a personal reflection of the influence Bill Strong had on the author’s career in noise control. From first encounters with the decibel to experimental and numerical research in trombone acoustics, from simple textbook quizzes to demanding 20-page single-problem essays, the author shows the influence Bill Strong had on his education in acoustics which became the bedrock for a career in machinery noise control. The presentation will cite specific example of concepts, analyses and techniques found in musical acoustics—first encountered by the author in his studies with Bill Strong—and similarities to industrial noise control situations. The examples will demonstrate how an education in musical acoustic translates to practical applications in noise control engineering.
Origin of negative density
Authors: Lee Sam Hyeon , Wright Oliver B.
Published: May 2016

We present a new physical interpretation for the effective densities. We introduce the idea of hidden force: the effective density is negative when the hidden force is larger than, and operates in antiphase to the applied force. We demonstrate this picture for some established acoustic metamaterials with elements based on membranes, springs, and masses. The hidden force for membrane-based acoustic metamaterials, for instance, is the force from the membrane tension. We also explain the analogous concepts for pure mass-and-spring systems, in which case, the hidden force can arise from masses and springs fixed inside other masses. This new picture provides a powerful tool for conceptual understanding and design of new acoustic metamaterials, and avoids common pitfalls involved in determining the effective parameters of such materials.
Evaluation of the resolution of a metamaterial acoustic leaky wave antenna
Authors: Rogers Jeffrey S. , Naify Christina J. , Guild Matthew , Rohde Charles A. , Orris Gregory J.
Published: May 2016

Acoustic antennas have long been utilized to directionally steer acoustic waves in both air and water. Typically these antennas are comprised of arrays of active acoustic elements which are electronically phased to steer the acoustic profile in the desired direction. A new technology, known as an acoustic leaky wave antenna, has recently been shown to achieve directional steering of acoustic waves using a single active transducer coupled to a transmission line passive aperture. The leaky wave antenna steers acoustic energy by preferential coupling to an input frequency and can be designed to steer from backfire to endfire, including broadside. This paper provides an analysis of resolution as a function of both input frequency and antenna length. Additionally, the resolution is compared to that achieved using an array of active acoustic elements. [This work was supported by ONR.]