bluuebunny/crossref_metadata_2025 huggingface dataset:
Acoustofluidic manipulation of biological bodies: Generation, visualization, and stimulation of cellular constructs
Authors: Carugo Dario , Hammarström Bjorn , Jonnalagadda Umesh , Lei Junjun , Plazonic Filip , Messaoudi Walid , Shaglwf Zaid Ibrahim , Glynne-Jones Peter , Hill Martyn
Published: June 2017

Ultrasound-based external manipulation of biological bodies in microfluidics has emerged as a contactless way of manipulating cells and particles for a range of applications, including sample enrichment, filtration, and sorting. Furthermore, it has been recently utilized to drive cells to form multi-cellular architectures, including clusters and planar sheets, by appropriately designing the resonant ultrasound field within the acoustofluidic device. In this presentation, we demonstrate the development of ultrasonic bioreactors for generating 3D, scaffold-free tissue constructs. We apply this technology to the generation of neocartilage grafts and examine their potential for repair chondral defects, and to the generation of co-culture models of the mucosal airway. Furthermore, we illustrate how the ultrasonic standing wave field can be designed to generate and modulate different stress regimes on suspended cells, for activating mechanotransductive pathways or for enhancing intracellular delivery of bioactive compounds. Integration of acoustofluidic systems with advanced microscopy techniques for quantifying biophysical effects of ultrasound on single cells or cellular constructs is also discussed.
How within-category gradience in lexical tones influences native Chinese listeners and second-language Chinese learners recognize words: An eye-tracking study
Authors: Qin Zhen , Zhang Jie , Tremblay Annie
Published: June 2017

This study investigates whether within-category gradience in lexical tones influences native and non-native Chinese listeners’ word recognition. Previous offline research found that Chinese listeners have a more categorical perception of lexical tones, and thus show less sensitivity to within-category variability in tones, than non-native listeners. However, it is unclear whether native and non-native listeners have sensitivity to within-category gradience during online word recognition. Native Chinese listeners and proficient adult English-speaking Chinese learners were tested in a visual-world eye-tracking experiment. The target was a level tone and the competitor was a high-rising tone, or vice versa. The auditory stimuli were manipulated such that the target tone was either canonical in the standard condition, phonetically more distant from the competitor in the distant condition, or phonetically closer to the competitor in the close condition. Growth curve analysis on fixations suggested that native listeners showed a gradient pattern of lexical competition, with less competition in the distant condition and more competition in the close condition than in the standard condition; learners, on the other hand, showed increased competition in both the distant and close conditions than in the standard condition. The native and non-native listeners’ difference suggested the influence of their language backgrounds.
Ambient noise correlations on a mobile, deformable array
Authors: Naughton Perry , Roux Philippe , Yeakle Riley , Schurgers Curt , Kastner Ryan , Jaffe Jules , Roberts Paul
Published: June 2017

This presentation describes a demonstration of ambient acoustic noise processing on a set of free floating oceanic receivers whose relative positions vary with time. We show that we are able to retrieve information that is relevant to the travel time between the receivers. With thousands of short time cross-correlations of varying distance, we show that on average, the decrease in amplitude of the noise correlation function with increased separation follows a power law. This suggests that there may be amplitude information that is embedded in the noise correlation function. We develop an incoherent beamformer, which shows that it is possible to determine a source direction using an array with moving elements and large element separation. We show how the noise correlation function varies in the presence of a boat with a known GPS trajectory, and how this information can be used recover the relative geometry of the deformable array. This work indicates that the relative geometry of an array can be estimated using only passive signals and the automatic identification system already present in many coastal communities.
Accommodation for assemblies in widespread use: The STC 50-ish wall
Authors: Markham Benjamin
Published: June 2017

The classroom acoustics standard ANSI/ASA S12.60 makes a compelling accommodation: a 20 cm (8 in.) concrete masonry unit wall, properly detailed, “…is an acceptable alternate assembly that conforms to the intent of [the requirements].” The relevant requirement is for a Sound Transmission Class (STC) of 50. This wall type is in widespread and generally successful use in U.S. school buildings with concrete construction. An analogous wall in widespread use in steel buildings is a single row of 92 mm (3-5/8 in.) metal studs with two layers of 16 mm (5/8 in.) gypsum board on each side and insulation in the stud cavity. Under certain stud configurations, this wall exceeds STC 50; in the most common stud configurations, however, it falls short. ANSI/ASA S12.60 makes no accommodation for this wall. With requirements for STC 50 walls in FGI guidelines for healthcare, the ANSI/ASA standard for schools, code requirements for multifamily buildings, and in other standards and design guidelines, there is an increasing need to reconcile compliance requirements with constructions commonplace in the United States. This presentation will examine first the acoustical data and then the design implications—both benefits and pitfalls—of accommodations in American standards and design guidelines such as the one made in ANSI/ASA S12.60.
David Wessel—A scholar and a performer
Authors: Morrison Andrew C.
Published: June 2017

In addition to his scholarly work in many fields related to the fields of music psychology and computer music, David Wessel was a gifted composer and a talented percussionist. In this presentation, I will mention my brief interactions with David as we looked at the acoustics of a unique musical instrument: the hand-played hang. The hang is an instrument inspired by the Caribbean steelpan which was popular for a time with many percussionists. After a few comments, we will remember David's musical legacy with some videos of his performances.
Quantifying connectivity to auditory cortex: Implications for crossmodal plasticity and hearing restoration
Authors: Butler Blake E. , Lomber Stephen G.
Published: June 2017

When one sensory modality is lost, compensatory advantages are observed in the remaining senses. There is evidence to suggest these advantages reflect recruitment of cortical areas that normally process sound. In the cat, crossmodal reorganization of auditory cortex appears to be field specific. While little or no activity is evoked in primary cortical regions by visual and somatosensory stimulation, higher-level fields confer increased peripheral acuity and improved visual motion detection. In order to better understand the changes in neural connections that underscore these functional adaptations, we have undertaken a series of detailed anatomical studies aimed at quantifying and comparing the patterns of connectivity in hearing and deaf animals. A retrograde neuronal tracer was deposited into auditory cortical areas, coronal sections were taken, and neurons showing positive retrograde labeling were counted and assigned to cortical and thalamic areas. Projections within and between sensory modalities were quantified; while some small-scale differences emerge, patterns of connectivity are overwhelmingly preserved across experimental groups within each cortical field examined. This structural preservation has implications for our understanding of the mechanisms that underlie crossmodal reorganization; moreover, it suggests that the connectivity necessary for resumption of auditory function may withstand even lengthy periods of deprivation.
Acoustic metasurfaces with rapid change profiles
Authors: Shi Chengzhi , Dubois Marc , Wang Yuan , Zhang Xiang
Published: June 2017

Acoustic metasurfaces with subwavelength unit cells modulating the phase of sound wave were developed to realize beam forming, steering, focusing, and recently carpet cloaking. However, these metasurfaces were used for small phase gradient applications and the ability to cloak or mimic reflection surfaces with rapid change profiles remained unexplored. Here, we analytically and experimentally investigate the effect of rapid change in-plane phase gradient on the design of acoustic metasurfaces for carpet cloaking and diffusing applications. Helmholtz resonators with different neck radii are used to form the ultrathin metasurface in our study. The variation of neck radius of the Helmholtz resonator results in different reflection phase of acoustic wave. In both analytical and experimental results, the large in-plane phase gradient does not affect the carpet cloak design, which is solely depending on the phase correction of the local profile height. On the contrary, the impedance mismatch resulted from the rapid change profile yields additional scattering to the reflection from such rapid change profiles. The recreation of the reflection pattern of rapid change profiles from a flat surface using metasurface needs to consider this multiple scattering, which requires additional amplitude modulation from the metasurface.
Model-based image reconstruction for medical ultrasound
Authors: Kruizinga Pieter , van der Meulen Pim , Mastik Frits , de Jong Nico , Bosch Johannes G. , Leus Geert
Published: June 2017

Most techniques that are used to reconstruct images from raw ultrasound signals are based on pre-defined geometrical processing. This type of image reconstruction typically has a low computational complexity and allows for real-time visualization. Since these techniques do not account for situation-specific parameters such as transducer characteristics and medium in-homogeneities, they cannot make proper use of the information that is contained in the raw ultrasound signals. In this paper, we explore the possibility of reconstructing images that best explain the measured ultrasound signals given the full ultrasound propagation model including all parameters. We build this model by measuring the spatiotemporal impulse response of the imaging transducer and, using the angular spectrum approach, estimate the ultrasound signal as it would originate from each individual image pixel position. An iterative search for the pixel combination that best explains the recorded signals provides the final image. We discuss the details of this model, provide experimental proof that this reconstruction allows for improved image quality, and extend our ideas to other imaging schemes such as compressive imaging.
Numerical simulation of transcranial ultrasound imaging using a two-dimensional phased array
Authors: Yuldashev Petr V. , Tsysar Sergey , Khokhlova Vera , Svet Victor D. , Sapozhnikov Oleg
Published: June 2017

Trans-skull ultrasound imaging of brain structures is a challenging problem because of strong attenuation of the skull and reflections from its boundaries. In addition, because the speed of sound in skull is much higher than in soft tissues, nonuniform thickness and heterogeneous bone structures cause strong refraction and aberration effects. In this work, transcranial ultrasound imaging of a 3D volume was simulated numerically. A linear wave equation in an inhomogeneous medium was modeled using the k-space method. A phased array comprising 10000 identically shaped square elements distributed over 70 x 70 mm2 area was used to generate a quasi-plane 2-cycle pulsed wave at 1 MHz. A spherical 3-mm diameter scatterer was placed 30 mm behind a cranial bone phantom with mass density 1900 kg/m3, sound speed 2500 m/s, and an irregular thickness varying from 5 to 8 mm. First, two reflections from the face and back sides of the phantom were used to determine its thickness. Then, a delay and sum algorithm was applied to the received echo signals to compensate for aberrations. It was shown that the scatterer was only visible when aberration compensation was applied. [Work supported by RSF-14-15-00665.]
In vivo measurements of muscle elasticity applying shear waves excited with focused ultrasound
Authors: Krit Timofey , Andreev Valeriy , Demin Igor , Rykhtik Pavel , Ryabova Elena
Published: June 2017

The common algorithm of shear waves excitation for diagnostical ultrasonic devices was modified for measurements in muscles. We measured the speed of shear waves, excited by a focused ultrasound at a frequency of 5 MHz in the muscles of the volunteers. Siemens Acuson S2000 was used for in vivo measurements. The suggested algorithm was tested on the muscle mimicking phantoms. The values of shear wave velocities in the same areas of studied phantoms at the same angles measured with Siemens Acuson S2000 system corresponded to the values obtained by Verasonics, where the region of shear wave excitation had a form of “blade” of thickness less than 0.5 mm, length and width of 1.5-2 mm. Due to this form of the region, the excited shear wave has propagated codirectional with the long side of the ultrasonic medical probe. Thus, the direction of propagation of the shear wave with respect to the phantom fibers, became dependent on the position of the probe. [The reported study was funded by RFBR and Moscow city Government according to the research project № 15-32-70016 «mol_а_mos», by RFBR according to the research project № 16-02-00719 а, and by Program for Sponsorship of Leading Scientific Schools (Grant NSh-7062.2016.2).]
Measuring sounds with a grid method with examining public spaces
Authors: Yildirim Yalcin
Published: June 2017

This study provides an outlook of the association between sound and public space by performing sound level meter in Dallas Fort-Worth metropolitan area. The main research question of the study is that whether the characteristics (program elements, position of public spaces and roads, and public space usage in different time intervals) of the public open spaces have relationship with sound levels. In order to demonstrate it, the applied sound level meter instruments for sound environment in public open spaces by using grid method. This study recommends that time intervals have effects on sound and practice should concentrate for this essential element. At this point, sound is forgotten component and it is not paid attention by urban planners, architects, landscape architects, civil engineering and many other disciplines. Presently, there are a few studies that are related to sound relationships in the United States. Hence, this research illustrates a point of view of a sound research for rapid growing urban areas.
Investigating processing delay in interaural time difference discrimination by normal-hearing children
Authors: Peng Z. Ellen , Fields Taylor , Litovsky Ruth
Published: June 2017

Recent work suggests that interaural time difference (ITD) thresholds are adult-like by 8-10 years of age in children with normal hearing (NH). If processing time is considered, however, we hypothesize that the ability to successfully extract ITDs is not fully mature in children. A novel paradigm was designed to simultaneously measure eye gaze with an eye tracker during an ITD discrimination task with mouse-click. Stimuli were 4 kHz transposed tones modulated at 128 Hz, tested with a 3-interval, 2-alternative forced choice task (left- or right-leading ITDs) with feedback. During each trial, gaze position on the computer screen was simultaneously recorded from stimulus onset to the time when a mouse click indicated either a left or right response. Processing times were extracted from the eye gaze data and compared with those from young NH adults. This presentation will focus on the developmental differences observed when threshold estimation is used versus when processing time is assessed via eye gaze measures. Results from this study will provide a better understanding of the developmental trajectory of binaural hearing abilities in NH children. [Work supported by NIDCD (R01DC003083 and R01DC008365 to Ruth Litovsky).]
The MITRE undersea sounding experiment 2016
Authors: Rotker Nicholas A. , Blair Ballard J. , Marcoux Caitlyn N. , Tooke Alexander J. , Udovydchenkov Ilya A. , Chandna Bindu , Meyer Melissa G. , Vincent Harold T.
Published: June 2017

This talk describes the MITRE Undersea sounding experiment (MUSE16) conducted in Narragansett Bay from September 12-23, 2016, where acoustic communication, localization waveforms, and signal processing techniques were explored. This experiment utilized newly developed acoustic buoys which were designed and built by the University of Rhode Island (URI) Ocean Engineering Dept. in collaboration with the MITRE Corporation. The buoys use Global Positioning Satellites (GPS) for localization and time synchronization and are capable of both transmitting and receiving acoustic data in the range of 8-18 kHz. The buoys were designed to further research in the areas of acoustic communications, channel modeling, and continuous active sonar (CAS). For the communication and channel modeling experimentation, modulated M-sequences of various sequence length were transmitted to explore channel characterization and communication enhancements. For the CAS experimentation, Linear Frequency Modulated (LFM) chirps of various bandwidths and center frequencies were explored as well as utilization of several underwater targets. A description of the prototype buoys including hardware, software, experimental setup, types of data collected, as well as some initial results will be discussed.
Generating the spatial forms of auditoriums based on distributed sentience
Authors: Mahalingam Ganapathy
Published: June 2017

The generation of the spatial form of an auditorium based on acoustical parameters related to Reverberance, Loudness, Clarity, Lateral Energy, and Balance was defined in the early 90s using a concept called “acoustic sculpting.” The central engine in the generation of the spatial form of the auditorium was the locus of the direct and reflected paths of sound from a source to a receiver. This defined an elliptical volume with two focii (source and receiver). In the initial implementation of “acoustic sculpting” in design systems for auditoria, this elliptical locus was used to generate the spatial form of the auditorium with just one source-receiver pair. In this paper, the initial concept of “acoustical sculpting” is extended, with loci generated by multiple source-receiver pairs. The elliptical locus is shown to address the key acoustical parameters. The generation of the spatial form of an auditorium from multiple elliptical loci, which define the distributed sentience of the audience, is proposed using Boolean operations. The generation of the spatial form of the auditorium proceeds from multiple desires for performance parameters at specific spatial locations, and is a desire-driven design. This will enable design solutions such as preferred seating and a tunable auditorium.
Sonic booms in atmospheric turbulence ground measurements in a hot desert climate
Authors: Haering Edward A.
Published: June 2017

The Sonic Booms in Atmospheric Turbulence (SonicBAT) Project flew a series of 20 F-18 flights with 69 supersonic passes at Edwards Air Force Base in July 2016 to quantify the effect of atmospheric turbulence on sonic booms. Most of the passes were at a pressure altitude of 32,000 feet and a Mach number of 1.4, yielding a nominal sonic boom overpressure of 1.6 pounds per square foot. Atmospheric sensors such as GPSsonde balloons, Sonic Detection and Ranging (SODAR) acoustic sounders, and ultrasonic anemometers were used to characterize the turbulence state of the atmosphere for each flight. Spiked signatures in excess of 7 pounds per square foot were measured at some locations, as well as rounded sonic-boom signature with levels much lower than nominal. This presentation will quantify the range of overpressures and Perceived Level of the sonic boom as a function of turbulence parameters, and also present the spatial variation of these quantities over the array. Comparisons with historical data will also be shown. The NASA Armstrong Research Center’s team is made up of KBR Wyle, Gulfstream, Boeing, Pennsylvania State University, Lockheed Martin, Eagle Aeronautics, and Laboratoire de Mécanique des Fluides et d’Acoustique (LMFA in France).
Exploring phononic crystal tunability using dielectric elastomers
Authors: Jandron Michael A. , Henann David
Published: June 2017

Tunable phononic crystals give rise to interesting opportunities such as variable-frequency vibration filters. By using soft dielectric elastomers, which undergo large deformations when acted upon by an external electric field, the frequency ranges of these band gaps may be adjusted, or new band gaps may be created through electrical stimuli. In this talk, we will discuss our finite-element-based numerical simulation capability for designing electrically-tunable, soft phononic crystals. The key ingredients of our finite-element tools are (i) the incorporation of electro-mechanical coupling, (ii) large-deformation capability, and (iii) an accounting for inertial effects. We present a demonstration of our simulation capability to the design of phononic crystals consisting of both square and hexagonal arrays of circular-cross-section threads embedded in a dielectric elastomeric matrix. Finally, we will consider electro-mechanical instabilities as alternative route for enhanced tunability. [This work was currently funded through the Naval Undersea Warfare Center Research program.]
An example of the restoration of a Monastic Churches with acoustic pots: L’Abbaye des Anges of l’Aber-Wrach (Britany)
Authors: Valiere Jean-Christophe , Bertholon-Palazzo Benedicte , Barone Nadia
Published: June 2017

“L’Abbaye des Anges” is a Franciscans Convent founded in 1507 in far-western France, close to Brest. The small church of this convent (2320 m3) contains in its liturgical choir’s walls about 110 acoustic pots, which is about 21 pots per cubic meter, by far the largest such installation in France. The archeological study shows that the pots have been inserted during the construction. It has also been proved by x-ray analysis that the pots were probably produced by potters close to l’Aber-Wrach, in Lannilis, where pottery tradition is attested from antiquity to the 20th century. The pots were obviously designed for exclusive acoustic use, as shown by their lack of glaze and their rounded shape which cannot be put properly on a table. Seven kinds of pots have been found with frequencies uniformly distributed between 150 and 300 Hz, unlike to what can be usually observed elsewhere in France. This frequency range corresponds to male singing voices (Baritone-Tenor). This suggests a rational choice as well concerning the musical point of view but also concerning acoustics. The owner would like to restore the church including all the acoustic pots.
Carstensen’s contributions to shear stress in strain and tissues
Authors: Parker Kevin J.
Published: June 2017

Some of Edwin Carstensen's final papers considered elastographic shear waves, which had opened up a new set of questions regarding stress and strain in tissues. Carstensen, from his commanding perspective overlooking nearly 70 years of fields and waves in tissues, could uniquely make the following statement: “At present, no consensus group has undertaken a systematic evaluation of the biological effects of low-frequency strains…Thanks to developments in the field of elastography over the last two decades, we now have the tools needed to measure low-frequency strains in tissues directly…Despite the fundamental importance of strain in bioeffects, no bioeffects investigators to our knowledge have taken advantage of these techniques. In fact, strain is rarely mentioned in the bioeffects literature” (Carstensen et al., “Biological effects of low-frequency shear strain: physical descriptors,” Ultrasound Med Biol 42(1)1-15, 2016). Indeed, with this topic, his “voyage of exploration and illumination” had truly come full circle, returning to some earlier questions but under new circumstances. We explore the deep issues Carstensen uncovered, including special forms of shear waves, the implications of Ostreicher's work, tissue viscoelastic response to shear stresses, and the inherent puzzles of linear hysteresis models.
Improving perforated plate modeling with porous media theory
Authors: Jaouen Luc , Chevillotte Fabien , Bécot François-Xavier
Published: June 2017

Acoustical facings (including micro perforated panels—MPP—woven and non-woven textiles, screens..) which can be used in association with porous materials, have been widely studied. A large number of models are described in the literature. This work presents a comparison of these models discussing particularly the expression of the corrections related to the pressure transition from the air inside the perforations to the outer media (air or porous materials) formulated in their resistive and reactive parts. Based on this analysis, it will be shown how to improve D. Y. Maa's model using the pioneer works by V. A. Fok, V. S. Nesterov or U. Ingard. Finally, the modeling of acoustical facings using classical porous models will be discussed. It will be shown how these porous models can be used to account for vibrations of the facings' skeletons or flow through the perforations in a non-linear regime.
Making the DYNAMAP project a reality in the suburban area of Rome
Authors: Bellucci Patrizia , Peruzzi Laura , Cruciani Francesca R. , Ferrari Cristina
Published: June 2017

The DYNAMAP project is a LIFE project aiming at developing a dynamic noise mapping system able to detect and represent in real time the acoustic impact due to road infrastructures (dynamic noise maps). Dynamic noise maps are achieved by updating pre-calculated basic noise maps as a function of sound pressure levels and weather conditions, provided by an automatic monitoring system, made of customized low-cost sensors and of a software tool implemented in a general purpose GIS platform. The feasibility of this approach will be validated by installing the system in two pilot areas with different territorial and environmental characteristics: an agglomeration and a major road. The first pilot area is located in Milan, in a significant portion of the town, while the second one is situated along the motorway A90 encircling the city of Rome. In this paper the main issues related to the preparation of the basic noise maps and the implementation of the Dynamap system in the suburban area of Rome are described. An overview of the test sites and of the system configuration is also provided.
Extended source models for long range wind turbine noise propagation
Authors: Cotte Benjamin
Published: June 2017

Wind turbine noise can be perceived at distances greater than one kilometer and is characterized by amplitude modulations at the receiver. In order to predict this noise, it is necessary to model the dominant aeroacoustic noise sources as well as the main outdoor propagation effects. In most studies from the literature, the wind turbines are modeled as point sources to simplify the coupling between source and propagation models, but this assumption is not always justified. In this study, two original methods are proposed to couple an aeroacoustic source model based on Amiet’s theory and a Split-Step Padé parabolic equation code for acoustic propagation in an inhomogeneous atmosphere. In the first method, an initial starter is obtained for each segment of the blade using the backpropagation approach. This method enables us to accurately model the directivity of the noise sources but is very computationally intensive. In the second method, the blade segments are viewed as moving monopole sources, and only a limited number of parabolic equation simulations are needed which strongly reduces the computation time. These two methods are validated using an analytical reference solution in a homogeneous medium and compared in various inhomogeneous atmospheres.
Predicting the pass-by signature of vehicle flow sound sources including the influence of nearby built environment
Authors: Pignier Nicolas. , O'Reilly Ciarán J. , Boij Susann
Published: June 2017

A numerical framework is presented aimed at evaluating the pass-by sound of vehicle sources in a simplified urban environment. By including the influence of the nearby built environment in the propagation approach, this method goes beyond the scope of the standard pass-by test performed on an ideal track in a free-field. This work allows for a complete modeling of the problem from sound generation to sound propagation in three steps. First, computation of the flow around the geometry of interest; second, extraction of the sound sources generated by the flow using direct numerical beamforming, and third, propagation of the moving sound sources to observers including reflections and scattering by nearby surfaces. The identification of the sound sources in the second step is performed using linear programming beamforming based on pressure data extracted from the flow simulations, resulting in a model of monopole sources. Step three uses a propagation method based on a point-to-point moving source Green’s function, ray-tracing techniques, and a modified Kirchhoff integral under the Kirchhoff approximation to compute first- and second-order reflections on built surfaces. The method is demonstrated on the example of the sound generated by an air inlet.
Pitch discrimination for multiple simultaneous complexes: Effects of harmonic resolvability
Authors: Graves Jackson , Oxenham Andrew J.
Published: June 2017

In natural listening contexts, especially in music, it is common to hear three or more simultaneous pitches, each defined by a harmonic complex tone. In order to extract the pitches of these tones using the rate-place code, peripherally resolved components are required, but the peripheral resolvability of a complex tone is reduced when multiple pitches are presented. In this experiment, we investigated the effect of resolvability on pitch discrimination in the context of multiple pitches. Listeners were asked to discriminate the direction of a 0.5-semitone pitch change at the end of a four-tone sequence, where the last tone in the sequence was embedded in a mixture of two other simultaneous tones. Tones were either pure tones, or complex tones filtered into one of two bandpass regions, in order to manipulate the extent to which harmonics were resolved both before and after mixing. Discrimination performance was significantly above chance, even in the high-frequency region where the combination of harmonic components should have been unresolved after mixing, suggesting that resolved harmonics may not be necessary to extract the pitch from multiple complex tones. Predictions from spectral and temporal models of pitch were compared with the results. [Work supported by NIH grant R01DC005216.]
Psychoacoustics in Germany in the period 1900 to 1950
Authors: Kohlrausch Armin
Published: June 2017

Psychoacoustic research in Germany in this period was performed in the context of various academic disciplines (experimal psychology, musicology, physics, communication engineering) and a range of institutions, covering both industrial laboratories (AES, Siemens & Halske), (technical) universities (Berlin, Breslau, Dresden) and (semi) governmental institutions like the Heinrich-Hertz Institut für Schwingungsforschung (Oscillation Research) and imperial mail research institutions. Prominent researchers were Heinrich Barkhausen (appointed as professor at the TU Dresden in 1911 for the field communications engineering); Erwin Waetzman (since 1912 professor at the University Breslau); Ferdinand Trendelenburg (since 1922 with Siemans & Halske, Berlin, in addition since 1935 adjunct professor at the University Berlin); Erwin Meyer, since 1928 at the Heinrich-Herz Institute in Berlin. The research questions were often derived from technical needs of the upcoming communication and radio industry, or addressed consequences of innovations like the car. Barkhausen introduced in 1926 a loudness meter (by comparison with a standardized reference), which was taken into production by Siemens a year later. Waetzmann’s habilitation thesis (1907, published as book in 1912) extended Helmholtz’ studies on the damping characteristics of “ear resonators.” Erwin Meyer started with binaural research in 1924 because he recognized its relevance for stereophonic sound reproduction.
Measurement of texture in polycrystalline materials using ultrasonic wave speeds
Authors: Lan Bo , Lowe Michael J. , Dunne Fionn P.
Published: June 2017

Manufacturing of metal components often results in significant texture, that is to say preferred orientations of their polycrystals. Since each crystal can be strongly anisotropic, this can give the component orientation-dependent material properties, affecting stiffness, thermal expansion, ultimate strength, and fatigue and creep resistance. So it is important to be able to measure texture, especially for high-value safety-critical components. Typically, the Orientation Distribution Function (ODF) of the crystals can be measured on exposed surfaces using EBSD, or in thin samples using neutron diffraction. But both are expensive, while there is currently no means to measure ODFs internally in real components. The authors have developed a method to determine internal texture from measurements of wave speeds at selected angles through the material. This is based on a convolution of wave speeds in a single crystal with the ODF, giving the resultant polycrystal wave speed angular function. Thus knowledge of the single crystal properties, together with wave speed measurements in the polycrystal, enables the ODF to be extracted. The method has been validated experimentally on flat samples of hexagonal and cubic materials, using ultrasound measurements in a water bath, and comparing the findings with neutron diffraction measurements, showing excellent agreement.
Coherent matched-filter reflection loss from a moving rough surface as a function of pulse duration and ensonified area
Authors: Abraham Douglas
Published: June 2017

The loss incurred when matched filtering a sonar pulse after reflection from a rough surface depends on the ensonified area on the surface and the motion of the surface throughout the pulse. Simple solutions exist for the loss in the coherently reflected component when the ensonified area is either very large or very small. The large ensonified area (LEA) result is generally accurate for narrowband pulses while a small ensonified area (SEA) requires broadband waveforms. By assuming the reflection comprises a finite number of statistically independent surface heights and that the surface is Gaussian distributed with a narrowband spectrum, the loss can be determined as a function of both the pulse duration relative to the wave period and effective ensonified area (which depends on pulse bandwidth) using the spatial correlation function of the surface. The result is shown to be a convex combination of the LEA and SEA results. A one-dimensional example illustrates how surface reflection loss increases with pulse duration but saturates when the duration exceeds the wave period. The loss is also shown to decrease as pulse bandwidth increases because of the reduction in the effective ensonified area. [This research was sponsored by the Office of Naval Research.]
Auditory bubbles: An application of relative weights to explore perceptual and neural representations of continuous speech
Authors: Venezia Jonathan
Published: June 2017

Several labs have recently developed relative weights procedures for estimating crucial time-frequency regions of the speech spectrogram. Due to the large degree of acoustic variability in natural speech, these spectrogram-based methods work best with rather limited sets of brief (e.g., syllable-length) utterances. We have developed a procedure that measures relative weights on the modulation power spectrum (MPS), which is obtained from the 2D Fourier transform of the speech spectrogram. Modulation patterns are relatively stable across utterances, which allows measurement of relative weights in the MPS domain using more ecologically-valid sets of continuous utterances (e.g., sentences). Our procedure works by applying randomly-shaped filters to the MPS over many trials and relating the filter patterns to an outcome measure using reverse correlation. Here, we estimate relative weights in the MPS domain for two outcome measures: keyword recognition/intelligibility (perceptual weights) and physiological activity measured with blood-oxygen-level-dependent fMRI (neural weights). Perceptual weights indicate that a circumscribed region of the MPS supports intelligible speech perception. Patterns of neural weights differ across regions of the auditory cortex—namely, primary auditory areas encode a broad range of the MPS while downstream regions converge toward a circumscribed representation that strongly resembles the pattern observed in perceptual weights.
Psychometric amplitude-modulation detection thresholds in chinchillas before and after moderate noise exposure
Authors: Maulden Amanda C. , Walls Michael K. , Heinz Michael G.
Published: June 2017

Recent findings from animal studies suggest that moderate-level acoustic overexposure can produce permanent cochlear synaptopathy while not significantly affecting hearing thresholds in quiet. It has been hypothesized that this hidden hearing loss may underlie difficulties some listeners have in noisy situations even with normal audiograms. However, this hypothesis has not been tested directly due to difficulties measuring behavior in animal models for which cochlear synaptopathy has been demonstrated, and the inability to measure cochlear synaptopathy directly in humans. We recently established a mammalian model (chinchilla) that has corresponding neural and behavioral amplitude-modulation (AM) detection thresholds in line with human behavioral thresholds, and which shows cochlear synaptopathy following moderate noise exposure. Here, behavioral AM-detection thresholds were measured in six chinchillas, before and after noise exposure, using the method of constant stimuli. Animals were trained to discriminate a sinusoidal AM (SAM) tone (4-kHz carrier) from a pure tone, in the presence of a notched-noise masker. Behavioral thresholds before noise exposure were consistent across individual animals and were in the range from -25 to -15 dB. Preliminary data collected following noise exposure do not show a substantial effect on AM-detection thresholds in this simple task. [Work supported by NIH grant R01-DC009838.]
Bearing of unmanned aerial vehicles by a volumetric microphone array
Authors: Haege Miriam , Oispuu Marc
Published: June 2017

The technical abilities of Unmanned Aerial Vehicles (UAV, here also denoted as drones) are steadily increasing. UAVs are often equipped with state-of-the-art technology which enables illegal surveillance and mapping of terrains and buildings as well as smuggling or even terrorism. For this reason, sensor systems are required which detect the intrusion of incoming drones in safety-relevant areas at an early stage. Beside other means, acoustical sensors can be used to detect approaching drones. In this paper we will present a volumetric array consisiting of 12 microphones, which enables to monitor the upper half sphere above the array. Efficient bearing algorithms like coherent or incoherent beamforming are employed to determine the direction of arrival (azimuth and elevation) of UAVs. These algorithms have also been tested within the framework of practical experiments. For this purpose, different types of UAVs flying on various courses around the microphone array were used. The performance of the applied algorithms as well as the microphone array could be successfully confirmed.
Underwater pipeline leakage detection via multibeam sonar imagery
Authors: Zhang Wanyuan , Zhou Tian , Peng Dongdong , Shen Jiajun
Published: June 2017

New developments in multibeam technology now permit MBES to collect and record acoustic data not only from the strongest return (normally the seabed), but also echo returns from the complete travel paths of the acoustic pulse through the water column. This now allows they are established as standard tools for the remote detection of targets in the water column, such as gas bubbles leaking from pipeline. In this study, a multibeam sonar operating at 300kHz is used to detect the gas leakage of pipeline based on acoustic backscatter imagery. Some behavioural traits of the leakage gas bubbles have been discussed, such as shape, distribution pattern and contour centroid characteristics. Firstly, an adaptive beamforming algorithm is applied to sonar imaging for suppressing background noise and side lobe interference. And then these features are extracted by mathematic morphological processing of image sequences. Finally, a tank test with different leakage scales caused by leakage pressures, amounts and sizes has verified the validity and stability of the characteristics of gas bubbles. The proposed method is feasible to make a qualitative assessment for AUV pipeline detection surveys.
Some practical issues affecting repeatability and reproducibility in laboratory transmission loss tests
Authors: Hoeller Christoph , Mahn Jeffrey
Published: June 2017

The ASTM standard E90 defines the measurement of transmission loss, equivalent to the sound reduction index defined in ISO 10140. ASTM E90 and ISO 10140 specify requirements for the laboratory, the test procedure and conditions, and for preparation and mounting of the specimen under test. Despite the strict requirements in ISO 10140 and the somewhat less strict requirements in ASTM E90, transmission loss results for nominally identical specimens often vary if measured in different laboratories, and sometimes even if measured again in the same laboratory. In practice, there are many factors that affect the repeatability or reproducibility of a transmission loss test for a given specimen. This presentation will not attempt to systematically cover all different sources of uncertainty, but instead will highlight some practical issues commonly encountered in laboratory transmission loss tests. Examples will be presented for a number of issues, including the effect of leakage through the specimen under test, the effect of varying temperature and humidity in the test chambers, and the effect of re-using gypsum board.
Impact of sound insulation quality in dwellings on its financial value
Authors: Vargova Andrea , Muellner Herbert , Exel Rudolf , Rychtarikova Monika
Published: June 2017

A lot of research has been already done on the assessment and improvement of sound insulation quality of partitioning elements in dwellings. Fewer studies have addressed the impact of acoustic improvements on those elements. Very little information is available on the impact of sound insulation properties on the global real estate value of dwellings as a hole. This contribution reports on the analysis of questionnaires and interviews concerning the overall satisfaction of dwellers about the acoustic comfort at their homes. The importance that people living in apartment flats in Slovakia give to their acoustic comfort at home is addressed, with the part of their budget that they would potentially consider to spend for improving it used as a measure.
Exploring novel beautiful, durable, hard, smooth, acoustically absorbent materials
Authors: Rehfuss Randall J. , Ermann Michael , Sullivan Martha , Hulva Andrew , Kern Alexander M.
Published: June 2017

Acoustically absorbent materials are generally “fuzzy.” This texture converts sound energy into heat through friction, thereby reducing the amount of sound that reflects back into the room.[1] In contrast, this research explores smooth surface alternatives to speech-frequency sound absorption by retracing the efforts of Wallace C. Sabine and his partner, architect and thin-structural-tile builder Raphael Guastavino. The two, each a luminary in his respective field at the time, teamed up in the early 1900s to manufacture sound absorbent ceramic tiles. After attempting to recreate and test the Sabine-Guastavino tiles, we sought to improve upon the concept of a porous, fire-proof, and acoustically absorbent tile to include a smooth surface that is easily sanitized to be used in facilities like child care centers, schools, and hospitals. While there are materials on the market that provide a smooth surface of micro-pores that open to a “fuzzy” material behind the surface, this novel material would be a continuous unit that would enhance the aesthetics of a space. To achieve this, we used an impedance tube to test the absorption of contemporary materials ranging from uncooked ramen noodles to cementitious composites, while simultaneously applying innovative methods and technology into the firing of clay bodies to achieve the desired surface smoothness and acoustic absorption in the vocal frequency domain.
Automated classification of Pacific white-sided dolphin (Lagenorhynchus obliquidens) pulsed calls for diel pattern assessment
Authors: Kanes Kristen , Dosso Stan E. , Lado Tania I. , Mouy Xavier
Published: June 2017

Diel patterns in marine mammal activity can be difficult to assess visually due to the cost of ship time and limitations of daylight and weather during expeditions that can bias analysis based on sightings. Acoustic data can be a cost-effective approach to evaluate activity patterns in marine mammals. However, manual analysis of acoustic data is time consuming, and impractical for large data sets. This study seeks to evaluate diel patterns in Pacific white-sided dolphin communication through automated analysis of one year of continuous acoustic data collected from the Barkley Canyon node of Ocean Networks Canada’s NEPTUNE observatory, offshore of Vancouver Island, British Columbia, Canada. In this study, marine mammal acoustic signals are manually annotated in a sub-set of the data, and used to train a random forest classifier targeting Pacific white-sided dolphin pulsed calls. Binary and multiclass classifiers are compared, and the effects of different data-balancing methods are evaluated. The results from automated classification of the full data set are used to determine whether a diel pattern in Pacific white-sided dolphin communication exists in this region.
The effect of respiratory gas composition on kidney stone detection with the color Doppler ultrasound twinkling artifact
Authors: Simon Julianna C. , Wang Yak-Nam , Thiel Jeffrey , Starr Frank , Bailey Michael R.
Published: June 2017

The color Doppler ultrasound twinkling artifact, which is thought to arise from microbubbles on and within the stone, has the potential to improve kidney stone detection in space; however, bubbles are known to be sensitive to the elevated levels of carbon dioxide (CO2) found on space vehicles. Here, we investigate the effect of respiratory gas composition on twinkling in swine implanted with kidney stones. Thirteen swine were initially exposed to either 100% oxygen (O2) or room air and then to air with elevated CO2 at 0.8%, 0.54%, or 0.27%. Stones were imaged with a Verasonics ultrasound system and ATL P4-2 transducer. The 9 swine initially breathing 100% O2 showed a significant reduction in twinkling when exposed to air with elevated CO2, with the degree of decrease in twinkling occurring in the order: 0.8%>0.54%>0.27% CO2. An additional 4 swine were oscillated between air with 0.04% CO2 (normal air) and 0.5% CO2. A reduction in twinkling was observed over the course of the experiment. The effect of respiratory gas composition should be further investigated before using twinkling to diagnose a kidney stone in space. [Work supported by NSBRI through NASA NCC 9-58 and NIH DK043881.]