bluuebunny/crossref_metadata_2025 huggingface dataset:
Sonobactericide: An ultrasound-mediated adjunct treatment for bacterial infective endocarditis—In vitro proof-of-principle
Authors: Lattwein Kirby R. , Shekhar Himanshu , van Wamel Willem J. , Herr Andrew B. , Holland Christy K. , Kooiman Klazina
Published: June 2017

Infective endocarditis (IE) is a bacterial infection of the surfaces within the heart, associated with high morbidity and mortality rates. The predominant bacteria causing IE are Staphylococci, which can bind to existing thrombi on heart valves and generate vegetations (biofilms). In this in vitro study, we test a novel strategy called sonobactericide to treat IE using ultrasound and ultrasound contrast agents, in combination with an antibiotic and a thrombolytic. We simulated IE vegetations using human whole-blood clots infected with Staphylococcus aureus. Histology and live-cell imaging revealed a biofilm layer of fibrin-embedded living Staphylococci. Infected clots were treated under flow for 30 min and degradation was assessed by time-lapse microscopy imaging. Clots were exposed to human plasma flow either alone or with different combinations of therapeutics: oxacillin (172 μg/mL), recombinant tissue plasminogen activator (rt-PA; 3.15 μg/mL), intermittent (50 s on, 30 s off) continuous-wave ultrasound (120 kHz, 0.44 MPa peak-to-peak pressure), and Definity (2 μl/ml). Infected clots exposed to the combination of oxacillin, rt-PA, ultrasound, and Definity achieved 99.3 ± 1.7% clot width loss, which was greater than the other treatment arms. These results demonstrate that sonobactericide may have potential as an adjunct therapy for IE.
The use of a novel microfluidics system for in vitro ultrasound-mediated drug delivery
Authors: Beekers Ines , van Rooij Tom , Verweij Martin D. , Versluis Michel , de Jong Nico , Trietsch Sebastiaan J. , Kooiman Klazina
Published: June 2017

Ultrasound insonification of gas filled microbubbles can be used to locally enhance vascular drug delivery [1]. Understanding of the underlying mechanisms requires an in vitro endothelial cell model that includes 3D cell culture and flow. We propose to use the elaborate microchannel system in the OrganoPlate™ [2]. Since it has never been used with ultrasound before, we assessed the feasibility of acoustic transmission. The oscillation of microbubbles in the OrganoPlate™ was recorded during ultrasound insonification (50 kPa, 1-4 MHz, 8 cycles) using the Brandaris 128 ultra-high-speed camera at 17 Mfps. We compared these oscillations to measurements performed in an acoustically transparent OptiCell [3]. From 1 to 1.6 MHz, larger oscillation amplitudes were observed in the OrganoPlate™, resulting from pressure amplification in the microchannels. Finite element modeling of wave propagation using PZFlex supported our findings. Successful sonoporation of 3D cultured endothelial cells was achieved in preliminary experiments using CD31 targeted microbubbles. The obtained microbubble oscillations and successful sonoporation demonstrate the potential of the OrganoPlate™ for an ideal in vitro model to investigate ultrasound-mediated drug delivery. [1] Kooiman, et al., Adv. Drug Deliv. Rev., 2014. [2] Trietsch, et al., Lab Chip, 2013. [3] van Rooij, et al., Ultrasound Med. Biol., 2015.
Acoustic microbubble trapping for enhanced targeted drug delivery
Authors: Nie Luzhen , Harput Sevan , McLaughlan James R. , Cowell David , Carpenter Thomas , Freear Steven
Published: June 2017

Systemic drug administration can result in low-efficiency therapeutic delivery (less than 1% to solid tumors) and potential side-effects by subjecting all tissues to toxic agents. Recently, targeted drug delivery and localized payload release has been a key goal of biomedical research. By combining ultrasound contrast agents (UCAs) with a therapeutic payload, promises potential for an enhanced therapeutic outcome. We have proposed a ultrasonic trap technique that is able to accumulate large populations of UCAs for enhanced localized release of a therapeutic agent. Sequences for UCA manipulation, fast imaging, and UCA fragmentation are interleaved with a same linear array medical ultrasound transducer. Once UCA clusters are halted in the trap within flow channels through custom-designed beam profiles, destruction pulses are transmitted to deliver therapeutic payload and simultaneous fast imaging depicts the flow dynamics. Verification of the simultaneous operation of trapping, destruction and imaging sequences is performed with a tissue-mimicking flow phantom and microscopy, respectively. Optical imaging clarifies UCAs can still be retained within the low pressure trap during the fast switch between different excitation schemes.
A universal data quality assessment method for human brain magnetic resonance elastography using an elastic spherical phantom
Authors: Brinker Spencer , McDannold Nathan , Mukundan Srinivasan
Published: June 2017

Human brain Magnetic Resonance Elastography (MRE) is on the verge of being utilized as a clinical diagnostic tool. Several methods are being investigated at multiple clinical facilities; however each have different ways of introducing vibrations into the brain and processing image data. These differences result in dissimilar complex shear modulus values, which make it difficult to reproduce and report brain tissue mechanical properties across the research community and in longitudinal clinical studies. Human brain MRE Data Quality Assessment (DQA) reporting methods are needed. This study investigates a universal method to regulate the precision and accuracy of MRE independent of the vibration system and post processing technique. A thin-walled 15.2 cm diameter acrylic sphere was filled with silicone gel. The phantom is designed to mimic human head, neck, and torso mechanics during human brain MRE scanning and is compatible with most brain vibration methods. MRE-derived storage shear modulus yields approximately 1.5 kPa (60 Hz vibration) using a custom air pillow system (Resoundant, Inc.). The material will be cross validated with rheometry for further validation. This study provides insight on design characteristics for a standard DQA phantom for regulating the quality of human brain MRE for research reporting and in the clinic.
Transoesophageal HIFU for cardiac ablation: In-vivo experiments in non-human primates
Authors: Greillier Paul , Ankou Bénédicte , Bessière Francis , Zorgani ali , Kwiecinski Wojciech , Magat Julie , Melot-Dusseau Sandrine , Lacoste Romain , Quesson Bruno , Pernot Mathieu , Catheline Stefan , Chevalier Philippe , Lafon Cyril
Published: June 2017

Transesophageal HIFU was proposed as an alternative to the current atrial fibrillation treatments. The present work described a feasibility study of transesophageal thermal ablation in the heart of non-human primates. An endoscope integrating a 5MHz 64-element commercial transesophageal echocardiography probe and a 8-element HIFU transducer was built. The transducer was cooled at 5°C and ultrasonic beam could be steered over a 15 to 55 mm range. The probe was tested in-vivo on three 30kg-baboons. Left atrium and ventricles were exposed to repeated continuous sonications (4-15 times during 16s) at a focal intensity of 3000 W/cm². B-mode, shear-wave and passive elastographies were performed before and after treatments in an attempt to monitor thermal lesions. T1 mapping and contrast MR imaging were realized the day after treatment. Clinical states of the subjects during and after the treatment were positive. One lesion in the left ventricle could be evidenced by elastography and confirmed by MRI. Experiments demonstrated the feasibility of a transoesophageal HIFU procedure to produce thermal lesions in beating hearts. Further developments will aim at improving the robustness of the technique. Work supported by the FUS Foundation. [Probe designed in collaboration with Vermon SA (Tours, France).]
Fluorescence activated cell sorting via focused traveling surface acoustic waves (FTSAWs)
Authors: Ma Zhichao , Collins David J. , Ai Ye
Published: June 2017

Fluorescence Activated Cell Sorting (FACS) is an essential technique widely used in biomedical analyses. Microfluidics, benefiting at its low power and sample consumption, has enabled miniaturization of the existing bulk FACS equipment into cost-effective and portable devices. However, these devices still have limited efficiency and biocompatibility whose actuation is based on dielectrophoresis, optical tweezers, and gas valve. Acoustophoresis, the migration of particles in acoustic field, has recently emerged as a promising method to manipulate suspended particles in microscale, thanks to the rapid response and good biocompatibility. However, limited by the wide aperture of the acoustic field, cell encapsulation in ~100s μm of droplets is one of the necessary procedures in the demonstrated acoustophoresis based FACS system to ensure sort single cell at each actuation, increasing the complexity of the system. In present work, a FACS system actuated by focused traveling surface acoustic waves has been developed. Since the aperture of acoustic field is reduced to the same order of cells by exploiting the focused acoustic waves, the cell can be sorted one at a time without encapsulation. Separation of circulating tumor cells (CTCs) from white blood cells (WBCs) was demonstrated to show good performance of the system.
Creating complex, controllable environments for scaffold-free tissue engineering using acoustic levitation
Authors: Anderson Brady J. , Sullivan Natalie , Sanjinez Dolly A. , Hamner Samantha , Doyle Timothy E.
Published: June 2017

Tissue engineering has been limited by the complex structure of biological tissue. Methods have therefore been devised using scaffolds made from synthetic materials (polymers) or natural materials (extracellular matrix from cadavers or animal tissues). These scaffolds are artificially introduced materials with potentially adverse side effects. This project’s objective was to determine the parameters necessary to create an environment to employ a scaffold-free method for building tissue. This method uses ultrasonic standing waves in fluid to generate complex patterns acting as a template to organize suspended cells into tissue structures. Parameters investigated included ultrasonic waveform shape, frequency, and intensity; water density and temperature; tissue cell size; transducer properties; and container configuration for standing-waves. Computer models were used to evaluate various container designs. Ultrasonic transducers from 0.20 to 1.0 MHz were coupled to containers and driven using an arbitrary waveform generator and RF amplifier. Polyethylene microspheres of 10-50 micrometer diameter were used to simulate biological cells. Experiments with cylindrical containers demonstrated that microspheres can be levitated in water to form layers, and revealed that the use of a square-wave modulated waveform generated more distinct layers. Experiments were also conducted with square containers using two transducers. These experiments produced a lattice-type structure of microspheres.
Acoustical bioengineering of cortex-like constructs by levitational assembly of primate neural stem cells
Authors: Padilla Frederic , Miskic Terezija , Bouyer Charlene , Wianny Florence , Dehay Colette
Published: June 2017

We combined bulk acoustic levitation with layer-by layer assembly to bioengineer cortex-like multilayered single constructs containing heterogeneous layers of cells, with micrometer-scale control over biological and structural features. The constructs were obtained by acoustically levitating, in a mix of fibrinogen and thrombin, primate Neural Stem Cells (NSCs) derived from monkey embryonic stem cells that stably express a tau-GFP fusion protein, enabling detailed visualization of living cell morphology, including dendrites and axons. The levitation process was repeated several times to superpose, in a single final construct with an interlayer distance of 180μm, the NSCs at three stages of differentiation, corresponding to brain progenitor cells and immature cerebral cortex neurons. The constructs were then cultured in neuronal differentiating medium, fixed and immunostained for confocal microscopy analyses. Immunostaining analyses revealed cells exhibiting neuronal and glial phenotypes. Complex intercellular connections formed by neurons and glial cells, and extending processes and inter- and intra-layers connections between layers of differentiated NSCs were monitored. The proposed acoustical method is potentially useful to create informative in vitro models of the developing primate brain, such as the multi-layered cerebral cortex, as it allows the assembly of heterogeneous cell populations, and supports proliferation and differentiation in 3D.
Simulation of phased array ultrasound propagation for fluid flow regulation in enhancement of bone adaptation
Authors: Saikia Eashan , Hassan Chaudhry R. , Qin Yi-Xian
Published: June 2017

Osteoporosis and induced risk of fracture have impact on aging population and our society. It has been shown that low-intensity mechanical intervention can promote local tissue formation using non-invasive ultrasound. The goal of this work was to evaluate dynamic acoustic radiation force (ARF) induced bone fluid flow (BFF) at the site of interests using nonlinear finite element analysis. ARF simulation was first generated by a 1x5 linear array transducer and then extended to a 5x5 array submerged under degassed water used for regulating fluid pressure gradient and flow. Both acoustic and porous media constitutive models were used to generate dynamic ARF wave propagation in the tissue. Simulations were modeled on a cortical bone specimen with a signal frequency of 1MHz for a series of Duty Cycle(%) and Pulse Repetition Frequency(PRF). The results showed that the displacement values obtained against a varying PRF follows the experimental trends of (Dayton et al., 1997) and displacement increases significantly for a Duty Cycle increase from 12% to 15%. Induced displacements plotted against time agrees with the experimental trends (Fan et al., 2013). The dynamic ARF created a pressure gradient of 0.6MPa/cm resulting in a relative displacement of 8μm between two points separated by 1mm.
End driven bender transducer
Authors: Butler Alexander L. , Butler John , Curtis Victoria
Published: June 2017

Piezoelectric bender transducers provide a low frequency resonance response from a simple compact structure. They often take the form of bilaminar or trilaminar piezoelectric ceramic discs or beams. The bending occurs in the piezoelectric ceramic discs or beams mounted on a simple support with the piezoelectric ceramic layers operating in phase oppositions creating the bending. The low tensile strength of the ceramic under hydrostatic pressure can be an issue with this type of transducer. We present here an alternative means for bender transduction in which the bending beam is a higher strength material, such as a metal, and the piezoelectric active section is now the end support, replacing the simple support of the legacy benders. The end supporting piezoelectric material is driven with the inner section operating out of phase with the outer section causing the bender beam to rotate on this piezoelectric simple support. In this design the major bending occurs in a higher tensile strength material capable of operating under high hydrostatic pressures. We present low frequency designs optimized for operation when end-driven by various piezoelectric materials. Typical transducer parameters and metrics are presented along with the transmitting response.
Modeling of 1D acoustic device composed of a planar beam and a fluid gap with discontinuity in thickness
Authors: Honzík Petr , Novák Antonín , Durand Stephane , Joly Nicolas , Bruneau Michel
Published: June 2017

Precise modeling of 1D acoustic devices (passive or active, miniaturized or not) containing a planar beam loaded by a fluid gap and cavities is of interest in a variety of applications (transducers, acoustic filters, metamaterials, etc.). An analytical approach presented herein enables to describe the vibration of the planar elastically supported rigid beam of rectangular cross-section surrounded by very thin slits and loaded by the fluid gap, which is divided in three parts of different thicknesses (the central part being the thinner one), the thermoviscous losses originating in the fluid being taken into account. Comparing to the case of the fluid gap of uniform thickness, such a geometry provides more parameters which can be adjusted in order to achieve the required behavior (resonant or damped, etc.). The analytically calculated beam displacement is presented and compared to the numerical solution provided by finite element method (a reference against which the analytical results are tested).
Contactless angular position control of objects using acoustic vortex beams in air
Authors: Muelas H. Ruben D. , Pazos-Ospina Jhon F. , Ealo Joao L.
Published: June 2017

Acoustic vortices (AV) are progressive and special fields exhibiting a helical wavefront. One of their most important features is the ability to transfer angular momentum to matter. Using AV, emerging technologies are aiming to non-contact manipulation, micro assembly and induced rotation of objects, among other applications. By controlling the amount of energy emitted, the topological charge and the size of the AV is possible to control/adjust the angular position of objects without touching them, as long as they can stably rotate. In this work, we show experimental results on the control of the angular position of disk-like samples (diameters between 5 cm and 10 cm) by means of an AV generated using a phase array system along with a 30-element multitransducer operating at 40 kHz in air. The samples were located 10 cm far from the AV generator. In particular, we analyze the effects on the dynamics of the controlled samples due to changes in the topological charge, the amount of energy radiated and the delay law used to generate the AV. Special attention is paid to the relative size of the AV with respect to the sample. Position errors lower than 1 degree are possible for the regulation problem.
On timbre in urban soundscapes: The role of fountains
Authors: Velardi Laura , Hermand Jean-Pierre , D'Autilia Roberto
Published: June 2017

According to European Environmental Noise Directive (2002/49/EC, 25 June 2002), acoustical issues in urban planning are mostly treated in term of loudness. However, timbre of urban sound sources, including their spectral features but not only, can affect our daily life due to auditory preferences. Social studies identify the sound of water as one of the most enjoyable sounds by humans and laboratory experiments demonstrate that testers prefer soft types of water sounds, with low frequency contents and low flow rates, such as natural stream and fountain. Recent surveys acknowledge fountains as acoustical urban elements, focusing on sound pressure level and spectrum analysis. In this paper, we will discuss observations made in Rome (e.g., Capitoline Hill) in 2015 and recently in Brussels, that suggest that fountain sounds may change habits and paths of passers-by. We will then present first findings from statistical analysis of the audio samples collected in situ, in an attempt to identify attributes of timbre that are responsible for shifted habits.
Application of the algorithm for time of arrival estimation of the shock waves produced by projectiles of different calibers
Authors: Vračar Miodrag S.
Published: June 2017

The topic of this paper is review of application of the algorithm for time of arrival estimation of shock waves produced by projectiles of different calibers. Time of arrival estimation of the shock waves is based on algorithm, which consists of wavelet decomposition, identification of the narrow data segment, which holds shock wave by wavelet coefficients and estimation the time of arrival of the shock wave by conventional statistical methods. Sources of the shock waves were projectiles which caliber varied from characteristic rifles, 7.62 mm, through large gun’s calibers up to 120 mm. Quality of the time of arrival estimate is verified on significant number of experiments. Estimated time of arrival is used in solving of the position of weapon when fire off happened. Localization of the shock wave sources was done by networked and in space distributed acoustic sensors. Discrete probability method, based on time differences of the time of arrivals obtained from multiple synchronized acoustic sensors, was used for localization of the weapon and these results are compared with their locations obtained by DGPS method.
Generalized finite difference time domain simulation on acoustical moving boundary problems
Authors: Wang Song , Hou Qingzhi
Published: June 2017

Mesh-free methods have the potential to solve acoustic problems with moving boundary, complex geometries and in flowing fluids. In this paper, generalized finite difference time domain (GFDTD), a time-domain representation of the generalized finite different method (GFDM), is extended to solve acoustic wave problems with moving boundary. To explore the numerical performance of GFDTD, its stability and phase velocity for wave propagations are firstly analyzed by von Neumann method. Compared with the other two widely used mesh-free methods, smoothed particle hydrodynamics (SPH) and modified smoothed particle hydrodynamics (MSPH), theoretical analysis shows that GFDTD has less dispersion, which is also well verified by 1D numerical tests. The GFDTD method is then applied to simulate wave propagation inside a 2D cylinder and the results are compared with those obtained by traditional finite difference time domain (FDTD) method. Finally, a moving boundary condition is introduced into the problem domain and the corresponding input impedance is analyzed.
Diving into the deep end: Transition from student to professor
Authors: Coyle Whitney L.
Published: June 2017

They kept saying don't worry—one cannot be taught how to teach. It takes experience, successes and failures, good and bad advice, and most of all, time. For a Ph.D. student this is terribly frustrating to hear. After 24 years of school, your job will now consist of a skill that cannot be mastered by studying. This aspect of a career in academia is one most are not prepared to face. Many are not willing to take that dive into the deep end and figure out how to make that transition successfully from student to professor due to an apparent lack of preparation—due to not being taught how to teach. It is not easy, but after two years in the game, I know it is worth it. This talk will focus on my experience throughout my recent start as a physics professor at a small liberal arts college. I will share some of the situations I felt prepared for (few) and those I was not (most). I will discuss my experience beginning research with undergraduate students, building a lab, writing lecture notes, and finding my voice as a new professor in the department and school.
Design of homework problems in physical acoustics
Authors: Blackstock David T. , Hamilton Mark F.
Published: June 2017

A variety of methods exist to help students master material in their acoustics courses. The method chosen depends a great deal on the course. In the graduate acoustics courses at UT Austin the methods include system identification and design projects in the course on acoustical transducers, measurements, and data analysis in the courses on architectural acoustics and ultrasonics, development of computer codes based on the sonar equation in the course on underwater acoustics, and a project usually requiring literature review in the course on nonlinear acoustics. Homework problems is the method of choice for the two-semester basic course on physical acoustics, because mastery of the fundamental principles of acoustics requires students to immerse themselves in the details specific to each particular topic. Learning basic acoustics is a lot like learning calculus: one learns by doing. This presentation discusses the philosophy behind creation of the homework problems that appear in the textbook Fundamentals of Physical Acoustics by Blackstock [Wiley 2000]. The problems do not require use of a computer. They do require judgment over plugging and chugging. The student must decide what section of a chapter applies to the problem assigned and also what approximations are permissible to simplify the work.
How understanding concerns of female students helps all students
Authors: Neilsen Tracianne B.
Published: June 2017

Studies on the high attrition rate of female students in STEM fields have identified general concerns that can cause women to leave. These include lack of prior experiences with engineering and computing, fears of failing, not fitting in, or being negatively impacted by stereotypes, a desire to contribute to society, and worries about future work-life balance. While women may be more affected by these concerns, male students can experience them as well. Thus, attempts to address these concerns benefit all students. The most straightforward ways to tackle these concerns are the same as the primary recommendations found in the physics education research literature for increasing student self-efficacy and constitute principles of good mentoring [Gee et al., Proc. Mtgs. Acoust. 23 025001 (2015)]. Foster a cooperative, inclusive, encouraging environment. Talk openly about concerns and mistakes to help students exchange the fear of failure for a drive to succeed. Provide ways for students to gain experience that is lacking. Emphasize applications to social and environmental issues to increase motivation. Be aware of subtle biases and discredit stereotypes. Acknowledge struggles of the work-life balancing act and promote family-friendly policies. Combined these actions build a supportive learning environment for all students.
Preparing students for undergraduate research experiences in acoustics
Authors: Piacsek Andrew A. , Gee Kent L.
Published: June 2017

At many primarily undergraduate institutions, and some PhD-granting universities, science and engineering faculty are expected to provide research experiences for undergraduates. One of the biggest challenges for faculty who supervise undergraduate research is preparing students to work productively with some degree of independence. In addition to having familiarity with relevant physical concepts and measurement methods, students must know how to use lab equipment safely, responsibly, and effectively. While required lab courses in typical physics and engineering departments expose students to general laboratory skills and measurement techniques, they do not typically include specialized equipment and methods used in acoustics research. This presentation will describe how an upper-division undergraduate course in acoustics can be designed to prepare students for a productive independent research experience in this field. Examples will be drawn from courses offered at Central Washington University and Brigham Young University.
Noise related calls to police departments in the United States
Authors: Blomberg Leslie D.
Published: June 2017

Noise is responsible for a significant number of calls to police departments. This paper seeks to quantify the scale and scope of the community noise complaints in police work. Fifty police departments were contacted to determine what percentage of “call for service” (the technical term for calls to police departments) were noise related. In addition, online data published by 150 cities were also included in the study. Noise complaints generally are responsible for one to five percent of calls to police departments.
Following up the European Directive on Noise
Authors: Schulte-Fortkamp Brigitte
Published: June 2017

Since 2002 the EU Directive on Noise (END) is available for the European member states followed by a number of activities to guarantee the protection against noise. So-called noise maps and action plans have been developed with regard to the different noise sources but also depending from the structure of the areas involved. This paper will describe the development in different member states, but namely in Germany to inform about the frame of duties and use of the guideline. It will also discuss how far the involvement of people concerned is part of the development. Furthermore, the recent review of the END will be presented.
Enforcement of local community noise ordinances in the United States
Authors: Blomberg Leslie D.
Published: June 2017

This paper is a follow-up of The Analysis of 500 Noise Ordinances, presented at the 171 Meeting of the Acoustical Society of America. In the first paper, the noise ordinances from the 500 largest communities in the United States were analyzed with respect to the regulatory tools, metrics and criteria communities use to regulate noise. The prevalence of various techniques employed in noise regulations were presented and discussed. The regulatory tools and techniques analyzed included pressure level limits, as well as nuisance, disturbing the peace, plainly audible, minimum distance, and time of day based regulations. In this paper, a random sample of the 500 noise ordinances were chosen, and the police departments in those cities were contacted, to determine how the ordinances were enforced, what regulatory tools were relied upon in enforcement, and why those tools and not others in the noise ordinance were used. Particular attention is given the role of decibel based regulatory tools including A-weighted, C-weighted, and octave band metrics in police enforcement of noise ordinances.
Online commentary on noise concerns, policy, and enforcement among readers in four countries
Authors: Botta Jeanine , Raab Karl H.
Published: June 2017

Decades’ worth of research findings tell us that most who are affected by noise exposure do not complain about it, and that noise complaints are not an accurate means of measuring community response. Much attention has been given to understanding the motivations of serial complainers, with less given to non-complainers. Are non-complainers unaware of noise policy, or how to submit a noise complaint? Research indicates that this is the case, and also suggests that some people think complaining would be a waste of time, that some are inhibited by social factors, and that some give up when previous efforts to address noise do not succeed. While noise complaints do not accurately measure community response, some policy and enforcement decisions are influenced by noise complaint data. Are there other potential means of capturing a measure of community response? This paper examines an unexplored resource for noise-related data online, where posts cover a broad range of experiences and opinions. Collecting reader comments in response to online news stories and blog posts, the paper uses content analysis to identify common themes, finding similar and disparate social expectations about noise policy and enforcement among readers from Canada, the United States, the United Kingdom, and Germany.
Community perception of noise impacts—A comprehensive review of background sound data for setting appropriate design goals for source sound (continuous, impulsive, tonal)
Authors: Farbo Aaron M.
Published: June 2017

Community perception of noise impact is most often influenced by the amount by which a new source of sound exceeds the existing ambient sound level. Various descriptors are used to define existing ambient sound levels. For example, the Massachusetts DEP Noise Policy uses the 90th percentile sound level (LA90), while the New York State DEC Noise Policy uses the equivalent sound level (LAeq). When new transient sounds are introduced into an environment the LA90 or LAeq may not be the best, or only, metrics for defining a design goal or noise ordinance limit. In addition to the lowest existing ambient sound levels, reviewing the first percentile (LA01) sound levels may be a more appropriate way to determine community perception of new transient sounds. Sound surveys from across the country were analyzed to determine maximum-recommended community sound levels (design goals). These design goals are based on marginal increases to the ambient sound level and comparison to existing maximum sound levels (LA01); the specific margin depends on the characteristics of sound experienced at the receptor.
Evaluating near-end listening enhancement in noise for normal-hearing and hearing-impaired listeners
Authors: Rennies Jan , Schepker Henning , Huelsmeier David , Drefs Jakob H. , Doclo Simon
Published: June 2017

Speech announcements in public spaces are often impaired by environmental noise, e.g., in train stations. In such conditions it is usually not possible to reduce the noise at the listener’s location, but the target speech can be pre-processed to enhance speech intelligibility (near-end listening enhancement, NELE). This contribution presents a series of listening tests to evaluate a NELE algorithm with normal-hearing and hearing-impaired listeners. The algorithm consists of several processing stages including dynamic range compression and frequency shaping. The algorithm either works under an equal-rms-power constraint (same rms level of processed and unprocessed speech) or additionally includes an adaptively controlled increase in rms level at constant peak level. Speech intelligibility was measured using the Oldenburg sentence test with unprocessed and processed stimuli in different types of background noise and SNRs. The results indicate that large benefits can be obtained even for constant speech level, but this benefit strongly depends on background noise type and SNR. The benefit is generally smaller for hearing-impaired than for normal-hearing listeners, but interindividual differences are quite large. All subjects benefit from the adaptive rms level increase, indicating that NELE algorithms with equal-rms-power constraints may not be sufficient for hearing-impaired listeners.
Influence of multiple moving noise distractors on spatial release from masking
Authors: Viveros Rhoddy , Peng Z. Ellen , Fels Janina
Published: June 2017

Previous studies on speech in noise are often limited to studying stationary sound sources in the virtual acoustic scene. Moving toward a more realistic acoustic environment, this study aims at expanding the knowledge of spatial release from masking (SRM) involving moving noises. Current mathematical models describe contributions of distractor asymmetry (on the same or different sides) and angular separation with the target in predicting SRM (e.g., Bronkhorst, 2000). In a previous study, we quantified SRM from single distractor traveling on a 90° trajectory. In this study, we add a second distractor to investigate how speech understanding is affected by distractors in movement in various trajectory angles, where only binaural cues are available. A speech-in-noise test with normal-hearing adults is performed using virtual binaural reproduction. Listeners are asked to identify spoken words by target in front (0° azimuth) under the presence of babble-noise distractors. Speech reception thresholds at 50% intelligibility are measured in 14 test conditions from 2 distractor spatial configurations (symmetrical vs. asymmetrical) X 7 trajectories (stationary at 0° and 90° and moving 15°, 30°, 45°, 60°, and 90°). Results will be presented to understand the role of binaural cues in speech understanding under the presence of moving noises.
How to reduce energy production plant noise annoyance using a sound design approach
Authors: Brocolini Laurent , Lavandier Catherine , Schmich-Yamane Isabelle , Alayrac Marion
Published: June 2017

Industrial plant noise is the result of a combination of many various sound sources. The spectral composition of these sound sources varies depending of the equipments: wide-band noises mainly related to cooling towers, tonal noises such as transformers and some other noises with spectral components in middle frequencies. The aim of this paper is to investigate the pleasantness/unpleasantness of industrial noise with a “sound design” approach. Sixteen different industrial stimuli were created combining cooling tower noise, transformer noise and another industrial source noise, mixed with two kind of background noise (“traffic road” and “nature”). With a computer tool, twenty-two people were able to change the composition of the industrial sound (without changing the overall SPL of 40 dB(A)) and design a better sound target by improving sound quality. The first result of this study is that the average optimized stimulus is composed with more of cooling tower noise and less transformer noise. This average stimulus is “a little more pleasant” than the original sound (on a continuous scale from “much more unpleasant” to “much more pleasant”). This increase in pleasantness (with constant overall level) has been translated into an equivalent reduction of about 2.5 dB(A) of the original sound.
Time-domain characterization of the nonlinear viscoelastic memory of rocks with ultrasound waves
Authors: Szabo Thomas L. , Feng Xuan , Liua Cai , Brown Stephen , Burms Daniel , Fehler Michael
Published: June 2017

The nonlinear elastic response of rocks is known to be caused by internal microstructure, particularly cracks and fluids. In order to quantify this nonlinearity, we describe a new sensitive acoustic method to measure nonlinear viscoelastic properties of rocks directly in the time domain. Our method utilizes co-propagating longitudinal acoustic waves to perturb rocks with dynamically applied strain. Data indicates that rocks have a short period nonlinear viscoelastic memory that is a function of the time history of the loaded strain. We developed a phenomenological model with second and third order nonlinear elastic constants and a memory strength parameter to describe the short period nonlinear viscoelastic memory and the nonlinear elastic behavior of rock. Results of experiments on Crab Orchard sandstone and Lucite samples are presented. We have found both Lucite and Crab Orchard sandstone to be viscoelastic but the sandstone is much more nonlinear. These new observations and methods have significance for quantifying changes in microstructure and pore fluids in rocks and other materials.
Comparison between the Gol’dberg number and the Morfey-Howell Q/S for finite-amplitude plane waves
Authors: Ohm Won-Suk , Gee Kent L. , Reichman Brent O.
Published: June 2017

In this paper we compare the two most popular indicators of nonlinearity, namely, the Gol’dberg number [Sov. Phys. Acoust. 2, 346-350 (1956)] and the Morfey-Howell Q/S [AIAA J. 19, 986-992 (1981)] for the case of an initially-sinusoidal, finite-amplitude plane wave in a thermoviscous medium. The Gol’dberg number Γ, defined as the ratio of the absorption length at the fundamental frequency to the shock formation distance, is a parameter that single-handedly dictates the entire history of the wave [for example, weak (Γ < 1) and strong (Γ >> 1) waves]. However, it fails to quantify the strength of nonlinearity that each individual harmonic “sees” at any given point. In other words, not every harmonic sees the apparent strength of nonlinearity according to Γ. The Q/S, on the other hand, is defined for each harmonic as a function of propagation distance, and hence keeps track of the ever-changing strength of nonlinearity during the course of propagation. One interesting ramification of this is that using Q/S it is possible to pinpoint the distance at which the value of nonlinearity relative to absorption actually becomes Γ for the fundamental component.
Application of Wald sequential test in staircase up-down adaptive procedures
Authors: Zera Jan
Published: June 2017

An advantage of adaptive, staircase, up-down procedures in sensory threshold measurements is that such procedures are based on simple rules for signal level setting and are relatively robust to fluctuations of the subject’s attention during the measurement. A disadvantage of those procedures is that they allow to estimate the threshold level only for a few points on the psychometric function. In this study an adaptive, up-down staircase procedure is proposed which uses a decision rule based on the Wald sequential statistical test, similar to that applied in the PEST adaptive method. The Wald test allows to determine the signal threshold level for any point on the psychometric function and is simple to implement. Numerical simulations and results of an experiment performed on real subjects have shown that the staircase procedure combined with a Wald test for signal level setting reproduces the tracks of standard up-down procedures and may estimate the sensory threshold with similar accuracy. The modified procedure is thus plausible for various kind of threshold measurements in psychoacoustic studies.
Reverberation limits the release from informational masking obtained by differences in fundamental frequency and in spatial location
Authors: Deroche Mickael L. , Culling John F. , Lavandier Mathieu , Gracco Vincent
Published: June 2017

Differences in fundamental frequency (ΔF0s) and differences in spatial location (ΔSLs) between competing talkers can substantially enhance intelligibility of a target voice in a typical cocktail-party situation. Reverberation is generally detrimental to the use of these two cues, but it is possible to create laboratory conditions where reverberation should not disrupt the release from energetic masking produced by ΔF0s and ΔSLs. Two masker types were used: a 2-voice speech masker and a non-linguistic masker (primarily energetic) matched in long-term excitation pattern and broadband temporal envelope to speech maskers. Speech reception thresholds were measured either in an adaptive procedure with unpredictable sentences or with the coordinate response measure at fixed target-to-masker ratios, in conditions with or without ΔF0s, and with or without ΔSLs, against the two masker types in anechoic and reverberant conditions. Both methods provided a similar pattern of results. In the presence of non-linguistic maskers, ΔF0s and ΔSLs provided masking releases which, as intended, were robust to reverberation. Larger masking releases were obtained for speech maskers, presumably due to the additional informational component, but critically, they were reduced by reverberation. Several interpretations will be discussed at the meeting.
Talker variability in real-life speech recognition by cochlear implant users
Authors: Tamati Terrin N. , Janse Esther , Pisoni David B. , Baskent Deniz
Published: June 2017

For adult cochlear implant (CI) users, understanding speech in the real world, outside the clinic, can be challenging. A fundamental attribute of real-life speech is the immense amount of talker variability, present from multiple talkers with diverse linguistic and developmental histories. Talker variability, beyond background noise or competing talkers, contributes greatly to real-life, adverse listening conditions. Normal-hearing listeners are able to quickly and efficiently adapt to and learn talker differences to facilitate speech recognition in these conditions. However, talker variability may be particularly detrimental to CI users, since they must rely on signals that are inherently degraded, missing spectro-temporal details. In three experiments, we examined the impact of different sources of talker variability (talkers, accents, speaking styles) on CI speech recognition. The results showed that CI users have difficulty recognizing speech with vast talker variability, and discriminating talkers’ voices and accents, with a great amount of individual differences in performance. These findings suggest that the well-controlled, low-variability conditions in the lab or clinic may not reflect actual CI users’ performance in daily life. [Funding: VIDI Grant (No. 016.093.397) from the Netherlands Organization for Scientific Research (NWO), the Netherlands Organization for Health Research and Development (ZonMw).]
Absence of ear advantage for segmental and tonal perception in noise
Authors: Gu Feng , Kwong Themis , Wong Lena
Published: June 2017

When different speech sounds are presented to the left and right ear simultaneously, right-handed listeners usually score higher for identifying stimuli presented to the right ear, reflecting the left hemisphere dominance for speech perception. Recently, the right hemisphere was proposed to contribute more than the left hemisphere for speech perception in an acoustically noisy environment. For testing this hypothesis, 40 right handed native Cantonese speakers were recruited for dichotic listening tests. Paired syllables were presented to participants in quiet and in noise (signal to noise ratio were set to 0 dB and -10 dB in two separate conditions). The two syllables in each pair differed from each other in consonant, vowels, or tones. Participants were asked to verbally repeat the syllable they thought was clearer. Accuracy rate was calculated for each ear. For the quiet condition, the mean accuracy rate was significantly higher for syllables presented to the right ear than those presented to the left ear for consonants, vowels, and tones. Whereas for both noise conditions, no significant ear advantage was found. The absence of ear advantage in noise suggested that the right hemisphere contributes more in a noisy environment than in quiet for both segmental and tonal perception.
Dynamic control over the allocation of listening effort in speech perception
Authors: Winn Matthew
Published: June 2017

Unlike typical laboratory and clinical testing situations, everyday speech communication involves hearing multiple consecutive utterances. Previous work has shown that effort allocated to perceiving degraded speech remains elevated until well after sentence offset, presumably to allow cognitive restoration of words that were missed, via contextual cues. This restorative process potentially conflicts with the perception of subsequent sentences. In this study we introduce various follow-up signals after a target sentence with the intent of interacting with the restorative processes used to recover intelligibility in difficult listening conditions. Pupillometry was used to gauge listening effort for a sentence followed by a critical 2-second window filled by silence, noise, or a random sequence of three digits; sentences were always repeated, and digits were repeated or ignored, in blocked sessions. Speech followed by noise elicited a pattern of effort that paused until the noise was over, and then resumed. Digits elicited a modest elevation in effort when they were ignored, but a considerable elevation when repeated along with the sentence. Notably, effort allocated to the sentence appears to be suppressed when the listener plans to attend to upcoming signals. Results suggest that responses to single utterances might not reflect dynamic cognitive demands in communication.
The effect of F0 contours on the intelligibility of speech against interfering sounds for Mandarin Chinese
Authors: Chen Jing , Yang Hongying , Wu Xihong
Published: June 2017

To study the role of F0 contour on speech intelligibility for Mandarin Chinese, speech reception thresholds (SRTs) of mono-tone speech and multi-tone speech were measured both in steady speech-spectrum noise (SSN) and in two-talkers’ speech (TTS). The effect of informational masking (IM) in TTS masking was also examined. The mono-tone speech was produced by mono-tone sentences, which only consisted of syllables with tone 1 or tone 0. All sentences used in this study were grammatically correct but semantically anomalous to avoid the effect of sentence context. The type of TTS maskers was also manipulated as mono-tone or multi-tone. The results revealed: 1) For SSN masking, there was no significant difference between the mono-tone speech and the multi-tone speech (-7.8 dB vs. -7.3 dB on SRTs), indicating a weak effect of altering F0 contour at the sentence level. 2) However, for TTS masking, the intelligibility of multi-tone speech in multi-tone masking was significantly difficult (2 dB increase for SRT) than other conditions, indicating an important role of F0 contour in IM. These results were different from the corresponding reports for English speech, and the characteristics of F0 contour and language were analyzed and discussed. [supported by a NSFC grant 61473008.]