bluuebunny/crossref_metadata_2025 huggingface dataset:
Volume velocity field and acoustics measurements in a canine larynx model
Authors: Farbos de Luzan Charles P. , Oren Liran , Khosla Sid M. , Maddox Alexandra , Gutmark Ephraim
Published: November 2017

In the classic source-filter theory, sound is produced at the glottis by a process known as flow modulation; in this case, “flow” specifically refers to the flow rate (Q) produced at the glottal exit during the phonation cycle. Flow modulation refers to the fact that Q is changing as the glottis opens and closes dQ/dt. Although dQ/dt is constantly changing from glottal opening and closing, the greatest rate of change happens during the latter part of closing, when Q rapidly decreases. This rapid deceleration is quantified by the maximum flow declination rate (MFDR). MFDR has been shown to highly correlate with acoustic intensity (loudness). The aim of this study is to measure changes in Q and the acoustic energy in a vibrating canine larynx model as a function of subglottal pressure and vocal tract constriction. Volume flow measurements are taken using time-resolved tomographic-PIV. Q at the glottal exit is extracted from PIV measurements and MFDR is computed from the waveform. Acoustic measurements (SPL) are taken simultaneously. Testing is done with and without vocal tract, which is place above the larynx. The constriction in the vocal tract is varied by changing the distance between the 2 false vocal folds (FVF). Each case above is tested at low and high subglottal pressures. Measurements show that the glottal exit flow is complex. The waveform of Q is skewed towards closing phase, even without a vocal tract. The skewing is affected further by the vocal tract constriction. Both MFDR and SPL increase with subglottal pressure.
Direction finding and inverse imaging with microphone arrays in a forest
Authors: White Michael J. , Swearingen Michelle E. , Guertin Patrick J.
Published: November 2017

Beneath the tree canopy, wind and temperature gradients are reduced, and so are wind noise and atmospheric fluctuations that cause acoustic scintillation. However, the large number of discrete scatting objects complicates the received signal in a repeatable manner. We placed three small arrays in a forest and operated a propane cannon in the area nearby to investigate the spatial and angular dependence of the received field and its correlations. As expected, scattering from trunks impairs the ability to find the source using the conventional beamformer. Several direction finding techniques were employed to evaluate the signal direction in this complex environment. Methods are compared against both measured data and a numerical scattering model for the same location.
Finite impulse response of an ocean acoustic waveguide by compressed sensing
Authors: Keiffer Richard S.
Published: November 2017

The usual approach to calculating the time domain acoustic response of an ocean waveguide is to Fourier synthesize it from a regularly sampled collection of frequency domain solutions. Depending on the details of the waveguide and the excitation signal, the resulting time series may be very sparse with significant time intervals of relative quiet between energetic multipath arrivals. This observed sparsity in the time domain suggests a computational advantage to synthesizing the time series by solving a convex optimization problem involving a much smaller set of solutions computed at random frequencies. The efficiency of the compressed sensing approach will depend on the sparsity of the time domain solution; the greater the sparsity in the time domain signal the greater the expected advantage of the compressed sensing approach. In this talk we examine the compressed sensing method of time series synthesis for a sequence of waveguides that range from extremely simple and ideal waveguides where the sparsity is expected to be great to the more realistic and complicated where the sparsity is expected to be reduced. [This work was supported by the U.S. Office of Naval Research.]
Exploration of acoustic spiral waves in an underwater environment
Authors: Eastland Grant
Published: November 2017

The work to be presented is regarding a research project to investigate the viability and possible application of spiral or helical acoustic waves for use in underwater environments. The investigation encompasses studies into the properties and generation of spiral or helical acoustic waves. Spiral waves can be generated by precisely controlling the phase of the wave, which could have different physical properties due to what is known as “topological charge.” This topological charge could be adjusted in some advantageous way, depending upon the desired application. In addition, reception of spiral or helical waves was investigated. The goal of the research is a proof of concept and presentation of the results of generation and reception of spiral acoustic waves. Spiral waves have been investigated for acoustic navigation and may lend itself well for use in other applications.
Using the argument of the Airy function as an analysis tool in ocean acoustics and oceanography
Authors: Chin-Bing Stanley A. , Fabre Josie P.
Published: November 2017

By assuming the index of refraction is linear between layers, it is possible to convert the depth dependent acoustic Helmholtz equation into an Airy equation. Decades ago this allowed the ocean acoustic pressure to be quickly calculated using tables of precalculated Airy functions with interpolation. High speed computers and the accurate parabolic equation model have rendered the Airy equation approach as a curiosity of history. However, the method can still be useful as an assessment tool. This has been demonstrated by using it to select similar ocean environmental parameters that have the same acoustic propagation characteristics. In this presentation, we apply the Airy equation method to evaluate the buoyancy frequency of similar ocean environments that support internal waves. A connection is made between the ocean acoustic propagation and the oceanography of the similar regions.
Historical evolution of sound diffusion in spaces for modern music
Authors: D'Antonio Peter , Madison Jeffrey , Cox Trevor J.
Published: November 2017

This presentation will review the historical evolution of the use of sound diffusors, from their initial use in recording control rooms to include almost all spaces for the performance, recording, and audition of music. Shortly after the invention of the reflection phase grating diffusor by Manfred Schroeder in 1973, the quadratic residue diffusor was installed in Michael Fowler Hall, New Zealand, Underground Sound recording studios in Largo, MD, and in the Oak Ridge Boy’s Acorn Studio in Henderson, TN. The initial acceptance of these new surfaces led to installation in hundreds of recording control rooms and live rooms, home theaters, stages, auditoria, and worship spaces. The design of sound diffusors was expanded to use optimization algorithms created by Cox and D’Antonio to include decorative shapes to complement the original phase grating surfaces, thus opening their use in all architectural acoustic spaces. Following a brief review of the design theory options, many applications over three decades, in a wide range of venues will be presented. A speculation on what the future holds, based on evolving diffusive designs and advanced manufacturing methods, will also be presented.
A 240-Seat Recital Space for Amplified Performance
Authors: Doria Damian , Kotch Dave
Published: November 2017

A new 240-seat recital space completed in 2017 for a Canadian University with a Bachelor of Music program teaching jazz, rock, pop, metal, blues, soul, county, electronica, and hip hop. The architectural design brief required a room that could accommodate the diverse programming of student recitals and other music sessions in a modern an aesthetically satisfying interior design. The concept for the room was quickly adopted by the Owner and Design Team, but included several room acoustics challenges. This paper will discuss the acoustical accommodation of activities in the recital space, along with integration of the house sound system, and a chronicle of the design, value-engineering, construction, and final commissioning process.
Worship space acoustics and architecture for contemporary services with modern music
Authors: Coffeen Robert C.
Published: November 2017

In relatively recent time, some religious worship facilities are presenting a contemporary worship service with music that can be considered modern and different from the more traditional music produced by an organ, piano, groups that employ instruments as used by a symphony orchestra, and by a choir. Modern music for a contemporary service is typically produced by a band using electric keyboards, electric and acoustic guitars, drums, and singing by a solo vocalist or by singing groups with all of the music electro-acoustically amplified. Thus, halls, auditoriums, and sanctuaries for contemporary worship services must generally be less reverberant than a facility for traditional music, and the sound reinforcement system must properly handle relatively high level music and vocals. It also seems that architecture for worship facilities where contemporary services will be held has changed from more traditional architecture to more informal designs with exposed ceiling structure, movable chairs, etc. This also seems to produce HVAC systems with higher noise due to exposed supply air ducts, short return air paths, and roof-top air handlers. Examples of and acoustical data for worship spaces with contemporary services will be presented.
A comparison of automated and manual techniques for acoustically identifying individual sperm whales with changing aspect
Authors: Tiemann Christopher
Published: November 2017

As shown by his extensive history of research in the Gulf of Mexico, Dr. George Ioup had a fascination with the marine mammals that lived there. In particular, he questioned whether individual whales of a given species could identify each other acoustically, and by extension, whether humans could do the same. George was an early proponent in the community of advancing automated methods for discriminating individual odontocetes by analyzing the clicks they make, a problem that grows considerably more difficult when multiple animals are clicking simultaneously. I had the good fortune of being able to explore this subject with George in an independent research project that may not have been widely reported but was important and enjoyable for us nonetheless. George realized quickly that conventional methods for automated grouping of clicks from the same click train were failing because there was no guarantee of click structure consistency as an animal changed aspect relative to a receiver. An automated method for grouping sperm whale clicks based on a cross correlation method originally applied to dolphin clicks provided the needed flexibility to follow an evolving click shape as shown by the close match between George’s automated results and my manually generated groupings.
Platinum films to carbon nano structures: The history of the thermophone transducer
Authors: Barnard Andrew R. , Asgarisabet Mahsa
Published: November 2017

The thermophone is a device which creates sound using rapid heat oscillations on its surface. This results in a thin and lightweight loudspeaker with no moving parts. Braun was the first to address this phenomenon in the late 1800s. Arnold and Crandall developed the first theory and correlated experimental results in 1917. Unfortunately, the materials necessary to make an efficient thermophone did not exist in their time. In 2008, Xiao rediscovered the thermophone effect using carbon nanotube thin films, a material much better suited to efficient thermophones. Since then many researchers have been working on developing thermophone technology using carbon nanostructures including nanotubes, nanofibers, and graphene. This talk will cover the history of the thermophone from its early days through today and give a broad overview of the application areas for this technology, which span from underwater transducers to consumer electronics and automotive applications.
Thermal and vibration induced rotor blade deicing using carbon nanotube thermophones
Authors: Senczyszyn Steven , Barnard Andrew R.
Published: November 2017

The accumulation of ice on helicopter blades imposes limitations on the design and operation of rotorcrafts due to the large power requirement of thermal heating mats. Carbon nanotube (CNT) loudspeakers present a lightweight and efficient solution to this issue, utilizing both thermal and vibratory methods to remove ice and prevent it from forming. To evaluate the deicing capabilities of CNT, an enclosure was created to encapsulate the loudspeaker between two thin layers of aluminum to simulate the rotor blade surface. The speaker was then operated at a range of amplitudes and frequencies in simulated cold weather conditions. Preliminary tests show promising results, with surface temperatures exceeding 120°C in under four minutes when operated in a −20°C environment and surface excitation resultant from the ultrasonic vibration. Although further testing is needed, CNT loudspeakers show great promise in becoming a lightweight and efficient solution to the issue of ice accumulation on the surface of rotor blades.
Student experiment for measure of target strength
Authors: Cao Zhengliang , Tong Jianfeng , Shen Wei
Published: November 2017

The target strength is a measurement of the reflection coefficient of a sonar target. Its value and feature is very important to detection and identification in active sonar, especially for fish by fishery acoustic students. A steel cylindrical shell is used as the target, whose outer diameter 194 mm, inner diameter 184 mm, length 500 mm, and both end closed covers with thickness 4 mm. A broadband transducer is selected to directionally project sound wave and a hydrophone receives the reflection wave from the target. The transducer and receiver are located at 5 m and 4 m from the target with the same depth 5 m in the water. When single frequency pulses are transmitted with signal interval frequency 50 Hz, the target strength is calculated by amplitude ratio of target echo and incidence wave at different frequencies. The result is compared with theoretical value for an infinite elastic cylindrical shell and finite length elastic cylindrical shell. This experiment will give a strategic guidance to understand what target strength is, how to understand it, and why we need it. [Work supported by National Natural Science Foundation of China (Grant No. 41374147).]
Full-spectrum comparison of denoising algorithms for real-time magnetic resonance imaging acoustics
Authors: Klock William , Barlaz Marissa
Published: November 2017

Using real-time MRI acoustic data, we employ two methods of signal denoising (DLWP and CS-SNG) to conduct a preliminary comparison between noisy, denoised, and noiseless data. The acoustic data collected in the MRI serve as the noisy, “baseline” group. Data collected from the same speakers in a sound-attenuated environment served as the noiseless, “ground truth.” We calculate acoustic power across the frequency spectrum in 32, 64, 128, and 256 bin experiments and perform k-means clustering on the first three principal components to compare the output of the denoising algorithms to the ground-truth and noisy data. Results show a quantitative difference between the denoising methods, through their different affinities for clusters associated with reference group labels. The groupings indicate that the CS-SNG data are better suited for establishing a map between the visual data from the MRI and the acoustic output because of its association with the noiseless data and its distinction from the noisy group. Since both denoising algorithms form independent clusters, there are potential differentiating features that could drive future improvement of these methods.
Localizing crow vocalizations in social aggregations
Authors: Flett Derek , Guy Virdie , Abadi Shima , Wacker Douglas
Published: November 2017

The North Creek Wetlands Restoration on the University of Washington Bothell campus is home to a large nocturnal American crow (Corvus brachyrhynchos) roost. Each day from Autumn to Spring, crows form pre- and post-roost aggregations, which consist of tens to hundreds of crows. Crows on these aggregations are often highly vocal, but the functions of their vocalizations are not well understood. Identifying any context-dependent patterns in these vocalizations is critical to fully understand communication in this highly social and intelligent species. Previous studies have shown the presence of human observers near large groups of crows may disrupt natural vocal and non-vocal behavior. In this study, the potential confound of these observer effects are eliminated by recording crow vocalizations using a remotely activated, time-synched microphone array. Simulations are undertaken to study the performance of the Time Difference of Arrival (TDOA) method to localize individual callers. A parametric study is used to analyze the effects of number of receivers, signal frequency and duration, and crow location on the performance of TDOA. In addition to the simulation, different types of recorded crow vocalizations are used to design robust playback experiments to fine-tune our localization technique for use in actual crow aggregations in future.
Computer simulation of synthetic aperture sonar or radar for classroom demonstration: Part II
Authors: Kirkwood Kathryn P. , Korman Murray S.
Published: November 2017

In our presentation, a Mathematica® simulation of Synthetic Aperture Acoustic Radar will demonstrate how point-like targets placed on a smooth surface can be imaged from a collection of acoustic echoes. The transmitter and receiver are collocated and modeled as a single element that stops along a linear track at collection points and hops to the next location (stop and hop approximation). The transmitter on the hypothetical apparatus will transmit a linear frequency modulated LFM chirp pulse that reflect off the targets and are recorded as echoes by the receiver at discrete locations along the track. A matched filter correlation process will perform a pulse compression of the LFM chirp. A series of still frames from the animated simulation will be displayed. These frames show the echoes arriving at different times from the targets in conjunction with a receiver wave recorder screen. The time correlation backprojection algorithm is motivated when pulse compressed arrivals are displayed (at various track locations) including the echo arrival of a hypothetical point target adjusted in the x,y plane on or near one of the actual point targets. [See Yegulap, “Fast backprojection algorithm for SAR,“ in Proc. 1999 IEEE Radar Conf., Waltham, MA, April 20–22, 1999, 60–65].
Investigation of sound level variations in occupied K-12 classrooms
Authors: Paine Jared , Wang Lily M.
Published: November 2017

Sound level data have been logged in 220 K-12 classrooms, as part of an investigation underway at the University of Nebraska—Lincoln on environmental conditions inside occupied classrooms. In each classroom, equivalent sound levels were logged every 10 s with an integration time of 10 s, during 36 hour periods that spanned two occupied school days, at three different times throughout an academic year. Previous presentations on this dataset have focused on average occupied and unoccupied sound levels for each classroom; this poster investigates the variation of the sound levels in the classrooms throughout the occupied days and how those differ across the grade levels measured (specifically, 3rd, 5th, 8th, and 11th grades). Among the quantifiers analyzed to understand sound level variation are standard deviation, L10-L90, and occurrence rates. [Work supported by the United States Environmental Protection Agency Grant Number R835633.]
Ultrasonic characterization of the complex Young's modulus of polymers produced with micro-stereolithography
Authors: Morris Clinton B. , Cormack John M. , Haberman Michael R. , Hamilton Mark F. , Seepersad Carolyn C.
Published: November 2017

Micro-stereolithography is capable of producing polymer parts on the scale of millimeters that contain micron-scale features. Accurate prediction of the dynamic performance of components produced using micro-sterolithography requires knowledge of the as-fabricated material properties, but very little published material property data exist for these materials. This is complicated by the fact that the properties vary as a function of build parameters (i.e., laser exposure time). Designers therefore have limited useful material property information for part design. Frequency-dependent material parameters are often determined by measuring the wave speed and attenuation of an ultrasonic pulse as it propagates through the material. This work employs laser Doppler vibrometry to detect extensional waves in a solid polymer rod of circular cross-section that is excited by a longitudinal ultrasonic contact transducer. Transverse motion associated with extensional waves propagating along the rod axis is measured at multiple surface points. The time series gathered from all locations are used to produce a frequency-wavenumber spectrum. These data, coupled with a forward model that accounts for both viscoelastic and geometric waveguide effects, are then used to invert for the lossy material properties from 0.4 to 1.2 MHz.
Asymmetric transmission via lossy gradient-index metasurfaces: Role of diffraction
Authors: Shen Chen , Li Yong , Xie Yangbo , Li Junfei , Jing Yun , Cummer Steven
Published: November 2017

The development of acoustic metasurfaces has enabled numerous wave control abilities. The effect of losses in acoustic metasurfaces for sound transmission manipulation, however, is largely unexplored. Here, we show that robust asymmetric transmission can be achieved by harnessing judiciously tailored losses. Theoretical investigations show that the asymmetric behavior stems from loss-induced suppression of high order diffractions. Multiple reflections occur inside the individual slits for the negative incident direction, which lead to different orders of diffraction and asymmetric responses for opposite directions. Numerical simulations based on effective medium are performed and are in good agreement with theoretical analysis. Real structures based on unit cells with designed internal viscous loss are fabricated and measured in a 2D waveguide. The peak energy contrast is about 10 times in a certain range of incident angles and frequencies. This study may open up new possibilities in lossy acoustic metamaterials and metasurfaces. The theory can also be readily extended to electromagnetic waves.
Closed-cell hyperelastic elements with mechanical instabilities and structural negative stiffness
Authors: Konarski Stephanie G. , Haberman Michael R.
Published: November 2017

Metamaterials are subwavelength structures that generate enhanced or exotic properties that are unattainable with conventional materials. One such class of metamaterials utilizes inclusions with mechanical instabilities to generate a non-monotonic pressure versus strain response and thus regions of structural negative stiffness. By embedding these sub-wavelength structures in a lossy matrix material, it is possible to tune and enhance material properties of the mixture such as acoustic and elastic nonlinearity and energy dissipation. Previous theoretical work on this topic by the authors has focused on a dilute concentration of these types of hyperelastic inclusions within a fluid or nearly incompressible elastic matrix material to determine the overall response via both quasi-static and dynamic nonlinear homogenization methods. The present work focuses on numerical analysis using the finite element method for closed-cell elements that display non-monotonic pressure-strain behavior. The objective is to design sub-wavelength, hyperelastic inclusions that are easy to embed in a fluid or polymeric background material in an effort to generate elevated parameters of nonlinearity or increased capacity to dissipate vibro-acoustic energy. Emphasis is placed on structures that can be fabricated using additive manufacturing techniques. [This work was supported by the Office of Naval Research.]
The hybrid Cramer-Rao bound of direction finding by a uniform circular array of isotropic sensors that suffer stochastic dislocations
Authors: Morris Zakayo N. , Wong Kainam Thomas , Kitavi Dominic M. , Lin Tsair-Chuan
Published: November 2017

Consider azimuth-elevation direction finding by a uniform circular array of isotropic sensors. In the real world, the sensors may dislocate from their nominal positions. These dislocations could be modeled as random variables having an a priori known distribution. This paper investigates how the dislocations would affect azimuth-elevation direction finding by deriving the corresponding hybrid Cramer-Rao bounds. Maximum a posteriori estimators are derived and Monte Carlo simulations are conducted to validate the derived hybrid Cramer-Rao bounds.
Incorporating image sources in the time-domain beamforming model for the localization of sound sources in reverberant rooms
Authors: Lam Alice V. , Hodgson Murray , Valeau Vincent
Published: November 2017

In this study, we use a small hemispherical microphone array to locate impulsive or stationary sound sources in reverberant rooms. A modified version of the conventional time-domain beamforming model was used, which incorporates physical information from the early specular reflections of the sound source, as well as the geometric and absorption characteristics of the room. In other words, the propagation model takes into account the potential image sources up to a given image order. We show that the technique can be seen as a time-reversal process, the measured pressure field being simultaneously re-emitted from both the actual array position and its virtual image positions. We then present results applying this modified model to simulated data (generated using an image-source propagation model), as well as measurements in real rooms, using both impulsive and continuous broad-band noise. In all cases, the modified model shows an improvement in localization over conventional beamforming. The issue of appropriately adjusting the image order and mixing time when performing the processing for optimal results is also addressed.
Path losses in sandy sediments with upward refracting sound speed profiles
Authors: Soloway Alexander G. , Dahl Peter H.
Published: November 2017

In this work, receiver-to-receiver path losses calculated from measurements of underwater explosions in shallow water (water depth ∼15 m) off the coast of Virginia Beach, VA will be presented. Within the approximate frequency range of 40 to 70 Hz, these data have path losses that suggest energy increasing with range by up to 10 dB. Above this frequency range, these data show energy decreasing with range as expected. An analytical model [Frisk, George V., “Determination of sediment sound speed profiles using caustic range information,“ Bottom-Interacting Ocean Acoustics. Springer, US, 1980, 153–157] and numerical propagation models will be used to show that these path losses can be attributed to an upward refracting sound speed gradient in the sediment. This upward refraction of sound waves propagating in the seabed results in the formation of caustics that define shadow zone boundaries. Below the cutoff frequency of the waveguide, receivers in the shadow zone will exhibit lower sound levels than receivers positioned farther from the source and outside of the shadow zone. While frequencies above cutoff will also undergo refraction in the seabed, the observability of this effect will be masked by trapped modes propagating in the water.
Azimuthal dependence of sound propagation due to seabed variability in shallow water
Authors: Badiey Mohsen , Wan Lin , Eickmeier Justin , Knobles David P. , Wilson Preston S.
Published: November 2017

In shallow water regions, the environment has complicated temporal and spatial variability including changes of bathymetry, sediment layer structure, bottom property, and physical oceanographic spatial and temporal changes due to processes like internal waves. All these effects can influence sound propagation in the waveguide. The azimuth angle dependence of sound propagation has been studied using the broadband acoustic signals measured at the Atlantic Generation Station site on the New Jersey continental Shelf, where two distinctive geologic/geoacoustic regions exist [J. Acoust. Soc. Am. 96(6), 1994]. The current paper revisits this idea by analyzing the modal dispersion of broadband acoustic signals deployed along circular tracks at the site of the Seabed Characterization Experiment 2017, where the seabed shows strong azimuthal dependent sub-mud layer ridges overlaid by a relatively uniform mud layer with variable thickness along different directions. The results of this paper can be utilized to assess the azimuthal dependence of the sound propagation in the mud patch region. [Work supported by ONR Ocean Acoustics.]
Development of highly diffuse surfaces from architectural concept to listening experience
Authors: Miller Gregory A. , Giegold Carl , Strong John T. , Brill Laura
Published: November 2017

Many different surface shapes can scatter sound effectively, but not every surface can scatter sound beautifully. When employed over large areas within performance spaces, reflections off sound diffusive surfaces must maintain much of the timbre of the original signal in order to preserve a sound quality pleasing to both performers and audience members. At the same time, these surfaces must be developed in ways that express the architect’s visual aesthetic of the room. This paper present means of evaluating and optimizing the sound diffusive capabilities of surfaces within performance spaces, from architectural concept through iterative computer modeling processes and ultimately to physical mockups that can be evaluated both objectively and subjectively.
Diffusion: When phase and energy can become more important than directivity to the perception of “space“
Authors: Sauro Ronald
Published: November 2017

This paper will present the newest research on the properties of diffusion that are becoming more important than just directivity to the perception of “space.“ This includes phase response and energy levels remaining after the act of diffusion.
Factors differentiating the 22.2- and 2-channel reproduced sound fields through an acoustic modeling of three listening rooms
Authors: Ashok Madhu , Kim Sungyoung
Published: November 2017

We have simulated two loudspeaker configurations (22.2- and 2-channel reproduction) using the CATT-Acoustic software and analyzed the influence of room acoustics on the perception of multichannel-reproduced music. With the rapid growth of virtual reality (VR) and mixed reality (AR), there is a need for an immersive acoustic system that can maintain compatibility of auditory impressions in various acoustic conditions. The research question of the authors’ project is whether an increased number of reproduction channels would reduce the room-induced perceptual difference. To answer this question, we have analyzed physical characteristics from calculated impulse responses (IRs) of three distinct room models (varying dimensions and reflecting surfaces). Among many characteristics, the early decay time (EDT) and clarity (C80) values covary with the loudspeaker configurations. The IRs calculated from a 22.2-channel reproduction system had different EDT and C80 values for all three rooms. The change was more evident in a reverberant room (a normal listening room) than a relatively dry room (such as studio control room), possibly due to boosts of the ratio of direct sound to late reflections. No salient factor associated with room differences was observed. The subsequent subjective evaluations, performed by eleven listeners, support that they weighted the perceptual difference associated with the reproduction format more over all other perceptual dimensions.
Influences of spatial variability in pelagic scattering layers on sperm whales behavior
Authors: Copeland Adrienne M. , Irvine Ladd , Mate Bruce , Au Whitlow
Published: November 2017

The central slope of the Gulf of Mexico (GOM) is home to over 20 species of marine mammals. Prior to the Deep Horizon Oil Spill in 2010, sperm whales were the predominately sighted large whale in the area. This study investigated the distribution and utilization of the north-central GOM by sperm whales two years after the spill by comparing sperm whale presence to micronekton distribution. Micronekton, organisms 2–20 cm, might be a key component in understanding sperm whale behavior as they are potentially an essential link in the food web between primary producers and higher trophic levels, including cephalopods—primary prey items of sperm whales. A Simrad EK60 echosounder operating at 38 kHz recorded the backscatter of micronekton throughout the northern GOM. The spatial distribution of micronekton backscatter was highly variable and may be driven by proximity to the Mississippi Delta. Sperm whales were sighted by trained visual observers and foraging was detected using a towed hydrophone array. The sperm whales were sighted most often in shallow slope waters less than 900 meters in areas with higher micronekton backscatter, suggesting that the waters above sloping bottoms with dense patches of mesopelagic micronekton support the prey of sperm whales.
Bottom characterization in the northern Gulf of Mexico using chirp sonar and ship noise data
Authors: Turgut Altan , Wood Warren , Soukup Raymond J.
Published: November 2017

As a part of Prof. George Ioup’s multi-institutional research initiative, chirp sonar bottom surveys were conducted near the Mississippi Canyon in the northern Gulf of Mexico during the Littoral Acoustic Demonstration Center (LADC) 2001 experiment. Bottom geoacoustic properties were estimated using a shallow-towed 2–12 kHz chirp sonar that provided sub-meter resolution and 60 m penetration. The inversion results showed that the experimental site is mainly covered with clayey sediment. In 2010, a second bottom characterization experiment was conducted at ∼25 miles NE of the LADC 2001 experiment site using a deep-towed chirp sonar. Deep-towed chirp sonar provided geoacoustic property estimations as well as low-grazing-angle bottom-loss measurements. As a source of opportunity, own-ship noise data were also used for geoacoustic parameter estimation and bottom-loss measurements. Geoacoustic parameter estimations and bottom loss measurements from the chirp-sonar and ship-noise data provided similar results that were also in agreement with those from the LADC 2001 experiment. [Work supported by ONR.]
Population densities of dolphins in the Northern Gulf of Mexico
Authors: Leftwich Kendal , Labien Jack G. , Austin SydiCharise , Wellmeyer Evan , Ioup Juliette W.
Published: November 2017

The Littoral Acoustic Demonstration Center–Gulf Ecological Monitoring and Modeling (LADC-GEMM) consortium collected underwater acoustic data in the northern Gulf of Mexico during the summer of 2015, returning to sites previously surveyed by LADC (2007, 2009, and 2010). Results presented here are produced using data recorded by the LADC-GEMM Environmental Acoustic Recording Systems (EARS) at the site closest to the BP oil spill, specifically for Rizzo, bottlenose, Clymene, and Pantropical-Spotted dolphins. Clustering and trained classifier techniques were used to isolate dolphin species. A population model developed by LADC-GEMM based on acoustic data collected from the EARS buoys is used to estimate the strength of delphinid recovery in the northern Gulf of Mexico after the BP oil spill. [This research was made possible by a grant from The Gulf of Mexico Research Initiative. Data are publicly available through the Gulf of Mexico Research Initiative Information & Data Cooperative (GRIIDC) at https://data.gulfresearchinitiative.org.]
Ultrasound molecular imaging of the secreted tumor marker Netrin-1 in multiple breast cancer models
Authors: Wischhusen Jennifer , Delcros Jean-Guy , Wilson Katheryne E. , Gibert Benjamin , Molina Rodolfo , Mehlen Patrick , Willmann Juergen K. , PADILLA Frederic
Published: November 2017

With regard to biomarker expression, tumors are heterogeneous media displaying intra- and interpatient variability. Ultrasound molecular imaging (USMI) is a newly developed tool that can characterize heterogeneous tumors. Here, we focus on Netrin-1-overexpressing breast cancer. A newly developed targeted therapy interfering with Netrin-1 requires patient stratification. We developed Netrin-1-targeted microbubbles (MBs) and assessed USMI for identification of Netrin-1-positive breast cancer. In vitro flow chamber assays showed specific binding of anti-Netrin-1-MBs to human and murine breast cancer cell lines overexpressing Netrin-1. In vivo, in Netrin-1-positive transgenic or implanted mouse breast cancer models, USMI showed significantly increased signals with Netrin-1-targeted MBs, compared with isotype control MBs and targeted MBs after blocking of Netrin-1:—44.8%, 32.0%, 33.7% intensity for MBsNetrin-1, MBsIsotype, or after blocking, resp., in MMTV tumors;—28.2%, 13.7%, 13.4%, resp., in SKBR7 tumors;—60.9%, 47.8%, 47.9%, resp., in 4T1 tumors. In Netrin-1-negative tumors and in normal glands, targeted and control MBs showed no significant differences. Immunohistochemistry confirmed the expression of Netrin-1 in endothelial cells. In conclusion, USMI allowed the characterization of tumor heterogeneity and the differentiation between Netrin-1-positive and -negative tumors, and has the potential to become a companion diagnostic for breast cancer patient stratification.
Development of tissue-mimicking phantom of the brain for ultrasonic studies
Authors: Taghizadeh Somayeh , Labuda Cecille , Mobley Joel
Published: November 2017

Constructing tissue-mimicking phantoms of the brain for ultrasonic studies is complicated by the low backscatter coefficient of brain tissue, causing difficulties in simultaneously matching the backscatter and attenuation properties. In this work, we report on the development of a polyvinyl alcohol (PVA) based tissue-mimicking phantom with properties approaching those of white matter tissue. PVA was selected as the base material for the phantom as its properties can be varied by temperature cycling, variations in concentration and the addition of scattering inclusions, allowing some independent control of backscatter and attenuation. The ultrasonic properties (including speed of sound, attenuation, and backscatter) were optimized using these three methods with talcum powder as a scatterer. It was determined that the ultrasonic properties of the phantom produced in this study are best matched to brain tissue in the frequency range 1.0–2.5 MHz, indicating its utility for benchtop ultrasonic studies in this frequency range.
In vivo radius bone evaluation in their teens by two longitudinal wave propagation
Authors: Matsukawa Mami , Mano Isao , Yoneda Yutaro , Horii Kaoru , Umemura Shiori , Ozaki Etsuko
Published: November 2017

An ultrasonic bone measurement system, LD-100 (OYO electric),1 has been developed for the evaluation of the distal 5.5% site of the radius of the non-dominant hand. The system measures two longitudinal waves (fast and slow waves) which propagate in the inside cancellous bone and echo waves reflected from the interface between the cortical and cancellous bones. The properties of these waves can give us the information of cancellous bones. We can also estimate the cortical thickness from the echo waves. For the small radius of teenagers, we have improved the system using an annular type transducer to avoid the effects of guided waves in the cortical bone. The radius bones of 654 teenagers were measured. The cortical thicknesses of female students in their late teens were around 95 % of the young adult mean (YAM), where those of male students showed variation from 90 to 100%. The cancellous bone densities in their late teens were 82–94% (female) and 66–85% (male). The growth of cancellous bone was late, which was clearer in men. In addition, the total bone growth of men seemed slower than that of women. 1H. Sai, et al., Osteoporos Int. (2010) 21:1781.
Assessment of granular distortion in digital sound recorders by statistical analyses of recorded sound and analytically distinguishing quality of 24-bit and 16-bit analog to digital converters
Authors: Biswas Amitava
Published: November 2017

Modern sound recording systems are mostly digital type, using at least one or several analog to digital converters that commonly provide 24-bit or 16-bit resolution and accordingly limits the recording quality. The use of such digitizers inherently add some granulation distortion. A 16 bit digitizer is theoretically limited to granulation step size of 1/65,536. Whereas a 24 bit digitizer is theoretically limited to granulation step size of 1/16,777,216. Smaller granulation step size provides better fidelity of the recording. This study explored the operational resolution of a few of such digital recorders by statistical analysis of samples of recorded sound tracks. The histogram of the digital samples of the sound recordings showed that a digitizer may not always be digitizing to the finest precision.
Writing an acoustics textbook under the ASA Press/Springer contract
Authors: Garrett Steven L.
Published: November 2017

The Acoustical Society’s Books + Committee decided to add first editions to their “classic reprints.” After a search process, the ASA decided that it was in the best interests of that project to team with Springer. A contract between ASA and Springer was signed in May 2013 creating a mechanism by which ASA members could propose and write new books. Members, student members, or registered meeting attendees could purchase paperback versions of those books produced under that contract for $24.99. Having just published my acoustics textbook [Understanding Acoustics; ISBN 978-3-319-49976-5], I will report on my experiences during the entire process, which begins with a book proposal. If the Committee believes that the proposed book would serve the interests of the membership, an individual contract is signed. Springer provides a “template” in MSWordâ or LaTEX format. I used the Word version that operated like any *.docx. Once the manuscript was complete, two ASA members were assigned as content editors for the technical review. Upon their approval, the layout, some redrawing of artwork, and a “grammar and spelling” review were done very quickly by Springer’s affiliate in India. I corrected my “author proofs” at a Springer web site that was amazingly user friendly.
Development of a simple replica of the middle ear pathology for demonstration of tympanometric measurements
Authors: Biswas Amitava
Published: November 2017

This study evaluates a simple replica of the middle ear pathology for demonstration of tympanometric measurements. Common tympanometers often use small passive cavities for calibration of basic measurements such as equivalent ear canal volume. But the real ear normally presents an inverted V shaped tympanogram. The pathologic ears present various characteristic shapes of tympanograms such as unusually high or low peaks. In some patients the tympanometric peak may be shifted away from the zero differential pressure point. Often such patients may not be readily available during a classroom demonstration of the procedures. Utility of this study to replicate such pathologic conditions with a simple model will be discussed.
Educational practice of linear array techniques at the Acoustics department of the Escuela Superior de Ingeniería Mecánica y Eléctrica campus Zacatenco, Instituto Politécnico Nacional, Mexico
Authors: Vivas Eduardo , Bustamante Omar A. , Beristain Sergio
Published: November 2017

Sound Source Location is a topic that has been studied over the past decades for a wide range of applications whether in air or underwater, resulting in the development of different sophisticated methods and systems. Nevertheless, this topic in not usually included in the curricula of acoustic courses for the requirement of expensive and specialized instrumentation. The purpose of this research is to develop a practical approach looking to involve the students by using common hardware for which they are already familiar with: hardware from the videogames industry. In the Acoustics department of the Escuela Superior de Ingeniería Mecánica y Eléctrica (ESIME Zacatenco), IPN Mexico, a low-cost Sound Source Location system has been implemented for this purpose. The system is built around a PS3 Eye digital camera that includes a linear array of four microphones, and Raspberry Pi microcomputer. The Beamforming algorithms are programmed in Python to provide flexibility and ease of experimentation. It was originally designed for research applications, and now it is a prototype for laboratory practice. The system provides the undergraduate students with the basics of linear arrays and associated processing techniques engaging the students by using familiar hardware from the games industry and real life applications.
Early history of the accordion family: Where did all the accordions come from?
Authors: Cottingham James P.
Published: November 2017

Two hundred years ago, there were no accordions. Free reed instruments were known in Asia for thousands of years, but the free reed instruments of European origin such as the accordion, harmonica, and reed organ were only invented and developed during the last two centuries. In 1780, Kratzenstein published a paper in St. Petersburg describing a speaking machine that produced vowel sounds using free reeds with resonators of various shapes. This event marks a convenient, if arbitrary, starting point for the history of the free reed musical instruments of European origin. These instruments developed rapidly, and by 1850, the accordion, concertina, harmonica, reed organ, and harmonium all had been invented and developed into more or less final form. This paper presents some episodes in the development of these instruments, in particular the accordion-concertina family, along with discussion of their acoustical design characteristics. Also addressed is the question of the influence of the Asian free reed mouth organs on the origin of the Western free reeds.
The craft of building Cajun accordions
Authors: Miller Larry G.
Published: November 2017

Craftsmen have been building single-row diatonic button accordions in South Louisiana since the mid-twentieth century. A brief history of this phenomenon will be given, followed by an explanation of how these accordions are constructed, from the perspective of someone who has made these instruments for decades, trained other makers, and served as the parts supplier for several shops. Topics covered will include the types of wood used, other parts and materials, design choices that affect sound quality versus visual appeal, special challenges in assembly, and tunings.
Cajun and Zydeco accordion playing styles
Authors: Huval Chad
Published: November 2017

The 10-button single-row diatonic accordion is a mainstay in the music of Louisiana's Creoles of Color and Cajuns. From the single-row diatonic accordion's appearance in the earliest recordings of Louisiana music to now, a unique syncopated playing style has developed, leading to today’s zydeco and Cajun styles. This talk will focus on how the 10-button single-row diatonic accordion is played, with demonstrations of the nuances that make it Cajun, or make it zydeco.
An overview of the key misperceptions that are preventing any significant improvements when addressing operational noise in acute care hospitals
Authors: Madaras Gary
Published: November 2017

The Making Hospitals Quiet program has been working with healthcare providers inside their existing and noisy acute care hospitals since 2011. An overview will be given on why misperceptions by healthcare professionals and acousticians have resulted in little improvement in the collective patient perception of quietness while admitted in these facilities. Tactics for overcoming these misperceptions will be discussed.