bluuebunny/crossref_metadata_2025 huggingface dataset:
A review of the medical applications of shear wave elastography
Authors: Tanter Mickael , Pernot Mathieu , Gennisson Jean Luc , Fink Mathias
Published: November 2013

Supersonic shear wave elastography (SWE) is a quantitative stiffness imaging technique based on the combination of a radiation force induced in tissue by an ultrasonic beam and ultrafast ultrasound imaging sequence (up to more than 10,000 frames per second) catching in real time the propagation of the resulting shear waves. Local shear wave speed is estimated and enables the two dimensional mapping of shear elasticity. This imaging modality is implemented on conventional probes driven by dedicated ultrafast echographic devices and can be performed during a standard ultrasound exam. The clinical potential of SSI is today extensively investigated for many potential applications such as breast cancer diagnosis, liver fibrosis staging, cardiovascular applications, and ophthalmology. This invited lecture will present an overview of the current investigated applications of SSI and the new trends of shear wave elastography research topics.
Ultrasound-based shear wave evaluation in transverse isotropic tissue mimicking phantoms
Authors: Aristizabal Sara , Kinnick Randall R. , Amador Carolina , Nenadic Ivan Z. , Greenleaf James F. , Urban Matthew W.
Published: November 2013

Introduction: Ultrasound radiation force-based methods can quantitatively evaluate tissue viscoelastic material properties. A limitation of current methods includes neglecting the inherent anisotropy nature of tissue. To explore this phenomenon, we created a phantom incorporating fibrous material that has preferential orientations. Methods: Two phantoms were made in a cube-shaped mold using a fibrous material arranged in multiple layers and embedded in porcine gelatin using two different concentrations of the gelatin (8%, 14%). Shear wave measurements were made in the phantoms at different angles by rotating the phantom, where 0° and 180° were defined along the fibers, and 90° and 270° across the fibers. Measurements were performed using a Verasonics ultrasound system equipped with a linear array transducer. Results/Discussion: The mean shear wave speeds and mean standard deviations for 8% and 14% gelatin along the fibers (0°) were (3.60 ± 0.03 and 4.10 ± 0.11 m/s) and across the fibers (90°) were (3.18 ± 0.12 and 3.90 ± 0.02 m/s), respectively. Conclusion: The fibrous gelatin-based phantoms exhibited anisotropy that could be measured using quantitative shear waves speed measurements. Increasing the gelatin percentage increases the shear wave speed and anisotropic moduli. [This study was supported by NIH grant DK092255.]
Angle exchange symmetries for acoustic Bessel beam scattering and the radiation force on spheres
Authors: Marston Philip L.
Published: November 2013

Bessel beams are characterized by a cone angle β and as previously noted there is an exchange symmetry in the scattering involving the cone and the scattering angle θ [Marston, J. Acoust. Soc. Am. 121, 753–758 (2007)]. The sphere is taken to be on the beam’s axis. In the present study a broader class of exchange symmetries in the scattering pattern in the (θ, β) domain are noted for vortex as well as zero-order beams. Reflection exchange symmetries are present in the scattering pattern about the lines: θ = β and (180 °−θ) = β. The radiation force is known to be affected by the angular asymmetry of the scattering pattern as a function of scattering angle [Zhang and Marston, Phys. Rev. E 84, 035601 (2011)]. It follows from angle exchange that the radiation force is similarly related to cone-angle asymmetry of the scattering pattern for a fixed scattering angle. This applies to negative as well as positive forces and is easily illustrated. [Work supported by ONR.]
Model-free quantification of shear wave velocity and attenuation in tissues and its in vivo application
Authors: Nenadic Ivan , Urban Matthew W. , Qiang Bo , Chen Shigao , Greenleaf James
Published: November 2013

We validate a technique for model-free measurement of shear wave velocity and attenuation. A mechanical shaker was used to excite harmonic plane and cylindrical waves in phantoms and excised tissue. Radiation force was used to excite impulsive cylindrical waves. 2D FFT of the displacement yielded the k-space whose coordinates are frequency and the wave number. The shear wave velocity at each frequency was obtained by finding the maximum at the given frequency in k-space and dividing the frequency coordinate by the wave number coordinate. The attenuation (α) at a given frequency was calculated using α = FWHM × π/√3, where FWHM is the full width at half maximum of the k-space peak along the given frequency. This method was applied to measure shear wave velocity and attenuation of transplanted kidneys and livers, and in the thyroid tumor, and compare it to the healthy tissues. The velocities and attenuations at each frequency for various excitation methods agree within one standard deviation. The k-space estimates of velocity and attenuation agreed with those obtained using the phase gradient (velocity) and amplitude decay (attenuation). The transplanted organs and the thyroid tumor had higher velocity and lower attenuation than healthy tissues.
Correlation of ultrasound speckle pattern and arrival time errors in shear wave elastography
Authors: McAleavey Stephen A.
Published: November 2013

Speckle results from coherent illumination and phase-sensitive detection of echoes from many sub-resolvable scatterers. Speckle provides a texture that allows ultrasonic tracking of tissue motion, which in turn enables the many varieties of ultrasound elastography. A complication is that the presence of speckle can induce a shift in the apparent phase or arrival time of a propagating shear wave. The correlation between shear wave arrival time and the speckle pattern measured with a stationary transmit beam and swept receive beams is demonstrated. Simulated transient shear waves generated in response to acoustic radiation force are tracked with transmit f-numbers of 2 to 4 and receive f-numbers of 2 to 8. The shear wave arrival time error and the lateral first moment of the swept-receive speckle pattern scaled by the shear wave speed are shown to be strongly, though not perfectly, correlated (r ~0.6). These arrival time errors are comparatively insensitive to the amplitude (over a range of −20 to 20 μm) and direction of propagation of the shear wave; e.g., arrival times for −20 and + 20 μm shear waves differed by <10% of the total arrival time error. Approaches for the suppression of speckle noise in shear wave elastography are discussed.
Modifying the just in time teaching strategy for introductory acoustics
Authors: Morrison Andrew C.
Published: November 2013

Just-in-time-teaching (JiTT) is a teaching and learning strategy where a feedback loop is created between instructor and students in order to focus classroom activities toward concepts the class is having the most difficulty in understanding. The two parts of a JiTT strategy are short exercises done outside of class and the response to the exercises in class. In previous iterations of my introductory course on acoustics, students have been assigned readings to complete and questions to answer based on the assigned readings. Students are required to answer all questions online before the start of class. The instructor is responsible for reading student responses before the start of class and has the opportunity to adjust class activities to address concerns raised by students in their answers. This year, we are modifying the JiTT method to encourage student reflection on the activities completed in class and emphasize critical reading skills. The benefits and challenges of the JiTT method and present modifications are discussed.
Using acoustics to enhance physics education
Authors: Neilsen Tracianne B. , Gee Kent L.
Published: November 2013

The authors were recently invited to write a Resource Letter for the American Journal of Physics on the role of acoustics in enriching physics education. The Letter contains citations related to textbooks, physical and virtual acoustics demonstrations, software, and instances where acoustical examples can lead to a deeper understanding of, e.g., general wave phenomena. This talk provides a summary of the diverse nature of resources that exist as well as specific tools and examples.
Techniques used to promote active learning in an undergraduate architectural acoustics course
Authors: Vigeant Michelle C.
Published: November 2013

The five-year undergraduate architectural engineering (AE) program at Penn State requires all students to take an introductory course in architectural acoustics (AA) and for most students in the program, no further AA courses are required. As a result, it is very important to capture the students’ interest early on in the course and use strategies that will improve long-term retention of the material. A number of techniques were used to improve student engagement with the introductory AA course that had an enrollment of 94 students. The first homework assignment was to summarize a recent magazine article in any area of acoustics, which allowed the students to immediately see a real-world application of the subject. During lecture periods, students were encouraged to participate through the use of personal response devices, also known as “clickers.” Several different types of clicker questions were used, including review questions from the preceding lecture, questions to prompt participation during the presentation of example problems, and conceptual questions. The results from the multiple choice clicker questions are immediately displayed, which provides useful feedback to both the students and the instructor. Some hands-on activities during the practicum periods were also incorporated to reinforce the content from the lectures.
Experimental learning in acoustics: A project oriented graduate course on architectural acoustics
Authors: Haberman Michael R.
Published: November 2013

The idea of learning-by-doing, known in educational theory as experimental learning, has wide acceptance as an efficient and effective teaching method. The subject of architectural acoustics is particularly well suited for this type of instruction. This talk reports on the current graduate course on architectural acoustics in the graduate acoustics program at The University of Texas at Austin, which attempts to implement an experimental learning approach. The course focuses on in-class demonstrations, site visits, and an extended course project to supplement traditional lectures. The talk will demonstrate how this approach satisfies an experimental learning model which emphasizes a cyclic process of abstract conceptualization (lectures on acoustical theory), experimentation and experience (demonstrations, visits, and projects), and reflective observation (reporting and testing). Specific example course projects are provided that illustrate the breadth and depth of course projects resulting from this approach and perspectives are provided for avenues for improvement using this teaching method.
Development of educational stations for the Acoustical Society of America outreach activities
Authors: Vongsawad Cameron T. , Neilsen Tracianne B. , Gee Kent L.
Published: November 2013

One of ASA’s outreach activities is hands-on exploration workshops for local school groups and girl scouts troops held during our semiannual conferences. In general, outreach programs have three main purposes: (1) public service, (2) generate enthusiasm and interest, and (3) supplement learning. Despite the good work that has been done in the past, it is apparent that the goals of the current ASA outreach activities could be better achieved through increased efficiency. This project continues the development of the ASA outreach programs held in conjunction with our meetings to better meet the above goals. Specifically, we have developed a structure in which demonstrations are grouped into five-minute stations each pertaining to a different physical system. To increase the ease with which volunteers can assist with the stations, one-page summaries and reference posters outlining the basic principals of each station have been prepared. Volunteers are encouraged to be guided by the interests of the students in their interactive discussions. In addition, we have created a brief introductory presentation for the workshops to explain what can be done in the field of acoustics. These improvements not only provide opportunities to excite student interest but also increase the efficacy of the outreach efforts.
Using game-based learning with integrated computer simulation to teach core concepts in underwater acoustics
Authors: Summers Jason E.
Published: November 2013

Game-based learning promises enhanced student engagement coupled with effective pedagogy, which motivated development of WaveQuest, a computer game that employs simulation to assist secondary students in learning core concepts from underwater acoustics. Prior work in physics education found simulations can aid learning by providing environments for inquiry that, through constraints on action imposed by concrete connection to the real world, implicitly scaffold the learning process, yet also support clarifying representations of phenomena unavailable to observers in the real world. The interactive 3D narrative game developed in this work provides motivational context for computer simulations and clarifying representations, which enables and assists students in pursing inquiry-based exploration of the simulated physical environment. At the same time, the level progression and game play naturally scaffold an adaptive learning process. Beyond facilitating this inquiry-based learning process, the game mechanics have been designed to incentivize players toward internalizing the novel concepts and models that are presented, in order to facilitate more rapid acquisition of new cognitive schema. This presentation will describe and demonstrate key elements of the game, with particular attention given to illustrating their relation to this pedagogical strategy. [Work supported by ONR Code 321 US.]
A water-level controlled wind instrument developed by a team-based project for an undergraduate acoustic class
Authors: Kang Seung-Cheol , Paeng Dong-Guk
Published: November 2013

During an introductory undergraduate class of acoustics, a team-based project was given to design and implement their own musical instrument, after studying basic concepts of resonance, standing wave, and modes of string, pipe, bar, membrane, and plate. One of the teams designed and implemented “W.L.C WINDY (Water-Level Controlled Wind Instrument),” which the length of the pipe can be adjusted by water level inside the pipe. The lengths satisfies the modes of a stopped pipe (open-closed end) with end correction. There are several advantages of this instrument for education of acoustics; cheap, easy to make, and easy to understand the principles of modes. It costs less than one dollar (a transparency hose, a syringe, an O-ring) to make “W.L.C WINDY”. This is how to make the instrument; 1. Connect a transparent hose with a syringe without needle using an O-ring. 2. Fill the hose with colored water for easy visualization. 3. Press the thumb rest of the syringe to make various sounds by controlling the water level. Even though W.L.C WINDY is not optimized to play music, it may contribute to easy demonstration of the principles of the modes for education of acoustics. [Supporting program: NIPA-2013-H0401-13-1007.]
Bob Apfel: Acoustics at Yale University and beyond
Authors: Ketterling Jeffrey A. , Holland Christy K. , Roy Ronald A. , Everbach E. Carr
Published: November 2013

Bob Apfel passed away in 2002 after having taught at Yale University for over thirty years. During his tenure at Yale, Bob graduated 28 Ph.D. students, trained 12 post-doctoral students and influenced countless masters and undergraduate students. Bob devoted considerable time and effort to the Acoustical Society of America (his honors include the Gold Medal for Lifetime Achievement, Silver Medal in Physical Acoustics, and the Biennial Award) and his influence is still felt by the continued involvement of many of his students. Prior to his time at Yale University, Bob trained at Harvard University with Frederic V. Hunt and the chain of advisors can be loosely traced back, all at Harvard, to 1802. Although Bob’s direct impact on the field of acoustics was prematurely cut short in 2002, his legacy and influence are still growing through the contributions of his students, and the students of his students.
The acoustic genealogy of the Nebraska Acoustics Group at the University of Nebraska—Lincoln
Authors: Wang Lily M.
Published: November 2013

The Nebraska Acoustics Group at the University of Nebraska—Lincoln was founded in the year 2000 with the hiring of Dr. Lily Wang into the newly formed Architectural Engineering Program. This poster will review the acoustic genealogy extending to and from this acoustics group, connecting to a number of other acousticians at academic institutions including Princeton University, Georgia Institute of Technology, Pennsylvania State University, Technical University of Denmark, Vassar College, University of Hartford, and Colombia College in Chicago. Connections to architectural acoustic consulting firms will also be highlighted.
Katherine Safford Harris’ academic family tree
Authors: Bell-Berti Fredericka , Raphael Lawrence J. , Kewley-Port Diane
Published: November 2013

At Haskins Laboratories, Katherine Harris lead a research team of engineers, programmers, technicians, ENT physicians, and fellow scientists to study speech production. As the reputation of this innovative research program grew, students, post-doctoral fellows, and visiting scientists from many universities and international laboratories came to join Kathy in this effort. Her contributions to training doctoral students grew when she became a faculty member at the CUNY Graduate Center. She was a pioneer role model especially—but not exclusively—for women scientists. Her enthusiasm and dedication to science attracted a host of students and young scientists who have gone on to academic research careers in Speech Communication. Kathy nurtured her students, always ready to listen and encourage, guiding but never pushing them through their degrees, and always keeping sight of the person.
One view of the Rudnick-Putterman UCLA-Acoustics dynasties
Authors: Garrett Steven L.
Published: November 2013

During the second half of the 20th century, the research group headed by Isadore Rudnick, augmented, then extended to this day by Seth Putterman, brought the formalism and techniques of classical acoustics to problems in the quantum mechanics of condensed matter systems. In doing so, Izzy advised 32 Ph.D. students who graduated between 1951 and 1986, half of which went on to academic careers of their own (excluding two of his sons who are also academic scientists), making the UCLA-Acoustics “family tree” extraordinarily dense and complex. Although Putterman’s academic roots can be traced all the way back to Stefan, Boltzmann, Ehrenfest, and Uhlenbeck, it appears that Rudnick’s inspiration was divine in its origin. Traveling forward from my time as a Rudnick-Putterman graduate student in the mid-1970’s, several clusters of my “academic siblings” (fellow graduate students and post-docs) can be identified that exerted a strong influence on acoustics research and education at the Naval Postgraduate School and Penn State and were influenced by the Swift-Wheatley-Migliori (Thermoacoustics) Group at Los Alamos National Laboratory.
Genealogy of the National Center for Physical Acoustics
Authors: Gladden Josh R. , Sabatier James , Bass Henry E.
Published: November 2013

NCPA traces its roots to the Physical Acoustics Research Group which grew from the Department of Physics and Astronomy. The current Department of Physics and Astronomy acoustics effort was initiated with Prof. F. Douglas Shields who received his Ph.D. at Vanderbilt University under the direction of Prof. Robert Lageman. Professor Shields came to the University of Mississippi in 1959. He directed the dissertation of 10 Ph.D. students and seven Masters students. In 1964, Prof. Shields was joined in the department by Prof. Roy Arnold who studied the ultrasonic properties of solids. Professor Arnold directed the dissertation of two Ph.D. students and six Masters students. In 1970, Prof. Randall Peters and Prof. Henry Bass joined the faculty; Bass doing acoustics in gases with a Ph.D. from Oklahoma State under Tom Winter and Peters doing solid state acoustics. The following year, Ron Carter joined the group doing solid state acoustics. Before his passing in 2008, Professor Bass directed the dissertation of nineteen Ph.D. students and eight Masters students. Professor Larry Crum, a student of Prof. Stump at Ohio State, joined the faculty in 1978. In 1986, an act of Congress established the National Center for Physical Acoustics and over a period of two years, PARGUM was transferred to NCPA. Professor Ralph Goodman joined NCPA as Director in 1989. A listing of all additional faculty and scientists to join NCPA and the students directed by all will be updated to 2013 and presented.
Making music: A serious attempt at designing new instruments by undergraduate students
Authors: Moore Thomas R. , Almond Joshua , Crozier Daniel
Published: November 2013

We describe a course in musical acoustics that required undergraduate students to design and build unique musical instruments, compose music for ensembles of them, and then perform the compositions in a public concert. Unlike most courses in musical acoustics which require the students to build home-made instruments as a final project, the construction of the instrument and composing original music were the primary goals of the course. The instruments were required to be artistic, visually interesting and play a pitch collection from the Western scale. We will describe the challenges and successes, show examples of the instruments, and review the lessons learned.
An interactive audio synthesizer for investigating formants and timbre
Authors: Piacsek Andrew A.
Published: November 2013

Computer-based investigations of the nature of formants and their role in characterizing vowel sounds and the timbre of musical instruments will be described. One version of this activity requires students to obtain detailed spectra of different vowel sounds, measure relative amplitudes of harmonics in the recorded sounds, and perform additive synthesis using Mathematica to recreate the different vowels. Students can investigate the minimum number of harmonics and formants needed to distinguish vowels. A new version of this activity relies on a recently developed interactive audio synthesis program that reduces the emphasis on tedious measurements and the need to edit Mathematica notebooks, allowing students to devote intellectual effort on investigation. The new program and the associated lab activity will be tested on students during Fall quarter of 2013 as part of the “Physics of Musical Sound” course at Central Washington University.
A laboratory investigation of the effect of trumpet mouthpieces in an introductory musical acoustics course
Authors: Morrison Andrew C.
Published: November 2013

In our introductory musical acoustics course for non-science majors, a major goal of the course is to introduce students to the principles of scientific thinking and investigation. Many students have preconceived ideas or beliefs about factors influencing the sounds produced by musical instruments. It is the role of the instructor to help students frame their ideas into scientifically testable experiments, which can be conducted in the laboratory. In our course, we have designed a laboratory activity to challenge students to explore the role of the mouthpiece of brass musical instruments. A parametric model of a trumpet mouthpiece is customized by students in order to investigate the effects of changing mouthpiece geometry on the trumpet acoustics. The models are manufactured on a 3D printer and used in the laboratory to make input impedance measurements. Students compare their quantitative results to the qualitative conceptions they held before completing the laboratory investigation.
The urgent need for standardization of soundscape
Authors: Schulte-Fortkamp Brigitte , Genuit Klaus , Fiebig André
Published: November 2013

In recent years, the soundscape approach gains increasingly in importance. It has shown its potential dealing with environmental noise issues, which conventional noise control approaches frequently fail to cope with. The soundscape concept is applied to comprehend the way humans experience and understand their acoustic environments. It does not simply reduce noise to an averaged acoustic quantity evoking unpleasantness estimated by statistical probabilities, but it considers noise as a valuable resource, which can be purposefully utilized. The standardization of “soundscape” in ISO 12913 is currently in progress. The standard will include definitions, terms and a conceptual framework illustrating that soundscape goes beyond physics and psychoacoustics, since it reflects human perception including cognitive aspects, context and interaction. The paper describes the progress in standardizing soundscape and the implications of the standard with its potential relevance to noise policy. Moreover, it discusses how to meet the challenge to standardize and harmonize the soundscape approach without losing the openness and multidimensionality of the soundscape idea.
Evaluation of indoor and outdoor soundscapes—The benefit of combining soundwalks and laboratory tests
Authors: Voigt Kay S.
Published: November 2013

Experiences and expectations of listeners have a significant influence to ratings of soundscapes. Sounds do not only occur on a single level of perception to peoples' ears, they appear with a setting of information of the source(s) to the “listening background” of the individual at a certain location. Although these possible combinations seem to be infinite, common judgments are unfolded on appropriateness of sounds on places. For the evaluation of two public indoor and two public outdoor locations in the city of Berlin, the soundwalk has been used with students in a series of five consecutive years to investigate predominant aspects of rating soundscapes. This tool provides a substantial data acquisition of the environment with technical measurements and documentations as well as ratings and appraisals by the participants. The data-triangulation enables to detect contextual moderators of the participants' evaluation by adjusting situational focus and importance. In subsequent laboratory tests—with the recorded stimuli—this connotation of non-acoustical features is discovered, especially by their absence, also the underlying attitude towards sound sources is identified. Finally, a reflecting discourse with the attendees on their ratings shows the need of elucidation of the meaning of individual use of words and phrases.
Delivering noise information to communities in presentations and with asynchronous media
Authors: Dubbink David
Published: November 2013

Working with communities to resolve noise problems demands not just accurate data about noise impacts but also effective means of exchanging information. The Interactive Sound Information System (ISIS), developed by the author, represents one means of presenting noise impacts data. Central to the ISIS concept is the idea that actual noise examples, shaped to reflect local situations, are the very best way to increase community understanding of noise management issues. Such a strategy works well in a public hearing or community workshop setting. Presentations can be structured to address local concerns and recorded sounds can be accurately calibrated. However, alternate modes of communicating information have been developed that are asynchronous and individual. The question is how to adapt presentations to such delivery systems and retain the reproducibility and accuracy of written reports or professionally moderated presentations. The paper describes current mechanisms for transmitting noise management data and explores the issues involved in adapting delivery to hand-held devices or other modes of individual access.
Prediction of offshore impact pile driving noise using numerical and analytical approach
Authors: Kim Huikwan , Miller James H. , Potty Gopu R.
Published: November 2013

Noise generated by offshore impact pile driving can radiate into and propagate through the air, water, and sediment. Predicting noise levels around the support structures at sea is required to estimate the effects of the noise on marine life. We have been investigated acoustic impact using our previously verified coupled Finite Element (Commercial FE code Abaqus) and Monterey Miami Parabolic Equation (2D MMPE) models [J. Acoust. Soc. Am. 131(4), 3392 (2012) and J. Acoust. Soc. Am. 133, 3419 (2013)]. A simple analytical model for the impact pile driving noise is developed to reduce computation cost and modeling effort when compared to the numerical model. In the present study, we are developing a Matlab based analytical model to calculate the Receive Levels (RL) in water. This analytical model solves simplified Donnell’s equation, i.e., governing equation for the thin cylindrical shell using the modal superposition approach assuming azimuthal symmetry. It solves the Helmholtz or Kirchhoff integral equation to evaluate the acoustic pressure field. We will compare the results of the coupled FE-MMPE numerical model and the Matlab based analytical model and discuss their advantages and disadvantages. [Work sponsored by the Link Foundation Ocean Engineering and Instrumentation Ph.D. Fellowship program.]
Anomalous ultrasonic transport in phononic crystals with overlapping Bragg and hybridization gaps
Authors: Page John H. , Lee Eric JS , Croënne Charles
Published: November 2013

Many of the interesting properties of phononic crystals are due to the existence of band gaps, which may arise from a number of different mechanisms. These include Bragg scattering as well as hybridization effects, the latter occurring when there are strong scattering resonances that hybridize with a propagating mode of the embedding medium. In this talk, we investigate the interaction between Bragg and hybridization effects on the band gap properties of 2D phononic crystals consisting of nylon rods arranged in a triangular lattice and immersed in water. The lattice constant and rod diameter were chosen to ensure that both mechanisms occur in the same frequency range. The scattering resonances of the nylon rods can be tuned in frequency by varying the temperature, enabling fine control of the overlap between hybridization and Bragg effects. The dispersion relations and transmission coefficient were measured experimentally from the phase and amplitude of transmitted ultrasonic pulses and calculated theoretically by finite element simulations. Strikingly unusual dispersion effects are observed, revealing a novel way of tuning band gap properties. These remarkable characteristics are explained by the competition between two co-existing propagation modes, reflecting strong coupling between scattering resonances of the rods.
Sonic fatigue coherence models
Authors: Blevins Robert D.
Published: November 2013

Computational and experimental based models for coherence in acoustic and turbulent pressure fields are developed for application to sonic fatigue of large structures—structures with dimensions greater than a wavelength or of the turbulence length scale. Conservative analytical methods for sonic fatigue of structures exposed to coherent pressure fields are first developed. Then models are introduced to account for finite coherence of turbulent and non-coherent pressure fields that arise in turbojet engines. The computational results are compared with experimental data.
Perception of stressed vs unstressed vowels: Language-specific and general patterns
Authors: Shin Priscilla , Warner Natasha L. , Hoffmann Maureen , McQueen James , Cutler Anne
Published: November 2013

Unstressed vowels are somewhat centralized (even full vowels such as the second in “city, taco"), reducing their acoustic distinctiveness. The current work compares listeners' perception of stressed and unstressed vowels in English and Dutch. The data come from two large projects on native listeners' perception of all possible diphones (CV, VC, CC, and VV sequences, all vowels stressed and unstressed) in English and Dutch. These datasets provide information about listeners' uptake of perceptual cues over time that is comparable across the two languages. Both groups perceived unstressed vowels less accurately than stressed, but this effect was far larger for English. English listeners showed a very large stress effect for lax vowels and a moderate effect for other vowels, while the Dutch listeners showed effects that were small and largely restricted to /a/. Dutch listeners may be able to identify unstressed vowels better than English listeners because the stressed-unstressed distinction has more informational value in Dutch than in English. However, both languages showed a larger stress effect just before a following consonant. This suggests that consonantal coarticulation obscures the quality of unstressed vowels in both languages. Thus, perception of stressed vs unstressed vowels demonstrates both language specificity and cross-language commonality.
Simple auditory elements induce perception of a phonetic feature
Authors: Finley Gregory
Published: November 2013

In this presentation, I demonstrate that certain nonspeech sounds can have perceptual phonetic value. I focus on a single phonetic/articulatory feature, lip rounding, and its detection in simple auditory stimuli. Behavioral experiments show that a rounding percept is possible for two types of nonspeech. One stimulus type, which yields the more robust response, is a complex periodic source filtered by a single narrow band reminiscent of a speech formant. The resulting nonspeech varies in perceived roundedness depending on the filter’s frequency, corresponding roughly with F2. The other stimulus type is a pure tone modulated upward in frequency. Preliminary results suggest that rounding can indeed be perceived on these sounds, but only with specific modulation rates within a certain frequency range. These findings indicate that minimally simple auditory objects, including pure tones and filtered bands, can be sufficient to encode phonetic information. Additionally, these two types of cues diverge in their ability to trigger this percept: a filtered band works as a static spectral cue, whereas a pure tone requires spectrotemporal modulation. This observation is consistent with findings that there are auditory STRFs specifically sensitive to modulation and the theoretical perspective that auditory organization directly predicts the processing of speech.
The effect of speaking rate, vowel context, and speaker intelligibility on the perception of consonant vowel consonants in noise
Authors: Raju Anirudh , Alwan Abeer
Published: November 2013

In this paper, we perform pilot experiments to evaluate the feasibility of a model to predict human recognition of speech sounds in the presence of noise at different speaking rates. CVC stimuli comprising a phonetically balanced set of 13 consonants and 3 vowels (/i/, /a/, /u/) were recorded in a sound proof booth by two talkers at two different speaking rates (fast and slow). Noisy stimuli were generated by adding babble noise at different levels to the quiet recordings. These stimuli were used to conduct perceptual experiments in which listeners were asked to listen and repeat back the CVC phrases presented in babble noise under 3 SNR conditions and both speaking rates. The data were transcribed by two trained linguists. Consonant confusion matrices were generated from these data and were analyzed by noise level, speaker, center vowel, and speaking rate. With the exception of /CuC/ stimuli, speaking rate had the most pronounced effect on perception with slow speech being more intelligible than fast speech in noise. /CaC/ stimuli were, on average, more robust than other stimuli in all conditions and one talker was significantly more intelligible than the other. Adetailed analysis of the results will be presented. [Work supported in part by the NSF.]
Psychophysiological indices of effortful listening in younger and older adults
Authors: Francis Alexander L. , MacPherson Megan K. , Chandrasekaran Bharath , Alvar Ann M. , Llanos Fernando
Published: November 2013

Older adults often have difficulty understanding speech in background noise, and this difficulty may be associated with cognitive processing demand. According to the effortfulness hypothesis, even sub-clinical age-related changes in hearing may increase cognitive demand for speech understanding, making listening in noise more effortful for older adults even when recognition performance is comparable to that of younger listeners. Separating speech from background noise requires both segregating target from masking signals and selectively attending to the target while ignoring maskers. While both segregation and selection may demand cognitive resources, it is not known whether both mechanisms interact with age to the same degree. To address this question, younger and older adults listened to and repeated sentences presented in quiet and under conditions that put relatively more emphasis on segregation (energetic masking using speech-shaped broad-band noise) or selection (informational masking using two-talker babble) or are cognitively demanding without masking (synthetic speech). Masked stimuli were equally intelligible based on prior research, so differences in listening effort may be attributed to age and/or masker type. Listening effort was measured behaviorally via traditional rating scales (NASA TLX), and psychophysiologically in terms of autonomic nervous system responses (heart rate, pulse period, and amplitude, and skin conductance).
Advances in biomedical applications of time reversal acoustic focusing of ultrasound
Authors: Sutin Alexander , Sinelnikov Yegor , Sarvazyan Armen
Published: November 2013

Time reversal acoustics (TRA) is one of the most efficient methods of ultrasound focusing in heterogeneous composite biological media, especially inside reverberating cavities, such as the skull. In this talk, we will overview several recently developed therapeutic applications of TRA focusing of ultrasound including enhanced drug delivery to brain tumors, generation of focal regions of complex shape tailored to the geometry of the target lesion and TRA dynamic focusing, that allows to maintain the constant acoustic intensity in the focus regardless the variation of acoustical parameters of the media. We are currently developing several new medical applications of TRA, such as remote charging of batteries in internal implants and leadless energizing deep brain stimulators, which are based on the possibility to remotely generate an electrical signal in tissue using TRA principles. These applications employ a TRA focusing system with wireless electromagnetic feedback from the tiny implanted piezotransducer acting as a beacon. The acoustic energy is accurately focused at the piezotransducer generating required electrical signal while providing minimum exposure of surrounding tissues to ultrasound energy. Possibility of remote generation of electrical signals in tissue with amplitudes reaching tens of volts was demonstrated. [Work supported by NIH R21 CA164935-01.]
Imaging the orientation of stress corrosion cracking using the three component time reversed elastic nonlinearity diagnostic
Authors: Reichman Brent O. , Anderson Brian E. , Ulrich Timothy J. , Le Bas Pierre-Yves
Published: November 2013

Linear acoustic techniques often are not able to locate closed cracks as the acoustic waves pass right through them. Fortunately, nonlinear acoustic techniques may be used in conjunction with time reversal techniques to not only locate a closed crack but also to image it. This presentation will discuss how cracks may be imaged using the three component time reversed nonlinearity diagnostic (3D-TREND). Specifically, the orientation of individual cracks in a 304L stainless steel plate, which resulted from controlled stress corrosion cracking (SCC) experiments, will be presented along with other imaging information about the crack. 3D-TREND is used to create an individual time reversal focus of energy at each inspection point of interest. The use of different frequencies and different excitation signals has been used in an attempt to extract more information about the crack. [This work was supported by the U.S. Dept. of Energy, Fuel Cycle R&D, Used Fuel Disposition (Storage) Campaign].
Future shallow water low frequency (100–1000 Hz) acoustic signal propagation physics studies
Authors: Orr Marshall H.
Published: November 2013

The measurement and prediction of the phase and amplitude properties of acoustic signals (1 to 1000 Hz) propagating in the dynamic shallow water (30 to 500 m water depths) environment has been a focus of the underwater acoustic research community for nearly 20 years. The majority of the ocean studies have occurred during late spring to summertime oceanic conditions when the sound speed variability was influenced by nonlinear mode 1 internal wavefields. Sound speed variability during the summer-to-winter and winter-to-summer water column transition periods will cause variability in the phase coherent properties of acoustic signals. Few experimental studies explicitly focused on quantifying the variability of phase coherent properties of acoustic signals during these periods have been performed. Illustration of the types of fluid processes that will perturb the sound speed structure during the fall-to-winter transition periods will be presented. Included will be mode 1 and mode 2 internal wave perturbation of the sound speed field as well as the locations and spatial scales of sound speed variability caused by interleaving water masses of varying temperature and salinity (Spice). Fall-to-winter transition sound speed fields will be contrasted with summer time sound speed conditions. [Work supported by the Office of Naval Research.]
Measured three-dimensional effects of mode-1 and mode-2 nonlinear internal waves on broadband acoustic wave propagation in shallow water
Authors: Turgut Altan , Mignerey Peter C. , Orr Marshall H.
Published: November 2013

Horizontal shadowing effects and frequency shifts of acoustic intensity level curves were measured with a bottomed horizontal array in the East China Sea during the summer of 2008. Low-frequency acoustic pulses were transmitted by two fixed sources at 33 km (270–330 Hz LFM) and 20km (450–550 Hz LFM) range. Strong shadowing effects were observed when mode-1 nonlinear internal wave fronts were nearly parallel to the acoustic propagation path. Numerical studies indicated that shadowing effects are more complex for mode-2 nonlinear internal waves due to acoustic-mode dependent focusing and defocusing. These effects were further analyzed using 3-D PE simulations for more dynamic mode-2 nonlinear internal waves observed on the US New Jersey Shelf. The shadowing was less pronounced for internal waves with curved wave-fronts and small amplitudes. However, regular and irregular frequency shifts were still present. The experimental observations coupled with 3-D PE simulations suggest that nonlinear internal waves may be sensed and characterized via low-frequency acoustic signals. [Work supported by the Office of Naval Research.]
Research methods: Beta-testing Facilities Guideline Institute's acoustical criteria—A case study of continual improvement in healthcare facilities
Authors: Rockstroh Kurt
Published: November 2013

Continual improvement processes (CIP) present opportunities and challenges for researchers. In healthcare, FGI manages a four-year building-code-development cycle that is continually improved by research and sets standards that others follow (USGBC-LEED, ICC). Innovative, accelerated research methods are needed to continually improve healthcare environments during a period of rapid and profound change, so FGI’s CIP method seeks to synchronize the work of code writers and independent researchers. One useful research method is to subject draft requirements to “beta-testing.” FGI leaders (led by the presenter) did this to test new acoustical criteria on a 641,000 “hospital of the future” wing at Tufts University's Baystate Medical Center in Springfield MA (a major hospital and Level 1 trauma center). Planning began in 2006 (using draft #1 of the acoustical guidelines); occupancy began in late 2012 (after the guidelines’ publication, Jan 2010). But only now, after a full year of occupancy, can the full cost and benefit of the improvements be measured using Federal HCAHPS (a new procedure required by the Affordable Care Act that impacts hospital reimbursements). “Beta test” results were factored into the forthcoming FGI 2014 edition. The “beta test” is the subject of independent, funded research currently underway.
New healthcare acoustics subcommittee: Overview and call for participation
Authors: Madaras Gary
Published: November 2013

The Acoustical Society of America (ASA) Technical Committee on Architectural Acoustics (TCAA) formed a new Healthcare Acoustics subcommittee at the 165th meeting in Montreal. The 1st meeting of the Healthcare Acoustics subcommittee will be held at the 166th meeting in San Francisco. This presentation will provide an overview of the purpose of the subcommittee and introduce possible initiatives on which the subcommittee may want to initially focus. Examples: 1. Despite financial incentive to make their hospitals quieter, most healthcare providers cannot significantly increase their “quiet-at-night” (HCAHPS) scores in their older or newer inpatient facilities. The national “quiet-at-night” (HCAHPS) score remains the lowest of all patient experience quality indicators. Changing things may require a significant paradigm shift in the architectural and acoustical communities. 2. The Facility Guidelines Institute (FGI) has developed its new Guidelines for Design and Construction of Residential Health, Care, and Support Facilities to be published in early 2014. Those Guidelines for eldercare facilities will include terms and concepts such as “nature sounds,” “positive auditory distraction,” “auditory landmark,” “music,” “quiet rooms,” “quietly operating,” etc., that have yet be fully defined acoustically. Please attend and participate.
Acoustic quality of buildings: Contributions to the workers health of the health area
Authors: Macedo Marta R. , Almeida Marcia S. , Teixeira Liliane R. , Gama Ana Paula , Silva Stephanie Livia S. , Dick Olga , Costa Isabele C. , Torreao Denise , Jorge Paulo Roberto L. , Dias Paulo Marcelo S. , Valente Daniel , Valente Diane R.
Published: November 2013

This work presents a case study carried through in a research center, education, assistance, and technological development in the areas of the health of the woman, child, and adolescent, situated in Rio de Janeiro, where pathologies of average and high complexity are taken care of. It intended detect environmental problems that could affect the health of workers of the institution, in order to support the elaboration of the action plan to mitigate urgent questions and to develop an architectonical project for a new center. The environments and processes of work had been evaluated, through a participative approach, being visited all the sectors of the center, carried through interviews half-structuralized with workers of all the sectors and promoted debates that had pointed the noise as one of the main factors of bother and stress. The observation in loco and analyze of the project allowed to detect that the architectural design and the disrespect of basic acoustics recommendations had contributed for this picture. Measurements carried through in some pointed areas as uncomfortable indicated to have exposition to sound pressure level above 75 dB(A). However, the resolution of the many of identified acoustic problems will have to wait the construction of the new headquarters.