bluuebunny/crossref_metadata_2025 huggingface dataset:
Prosodic characteristics of speech directed to adults and to infants with and without hearing impairment
Authors: Dilley Laura , Wieland Elizabeth , Burnham Evamarie , Wang Yuanyuan , Houston Derek , Kondaurova Maria V. , Bergeson Tonya
Published: June 2017

Infant-direct (ID) and adult-directed (AD) speech are distinguished via multiple acoustic-prosodic characteristics, but it is unclear how these differences map onto linguistic constructs, including pitch accents, prominences, and phrasal boundaries, or how a child’s hearing impairment affects caregiver prosody. In two studies, trained analysts coded prosody in corpora of mothers reading to their children (ID condition) or another adult (AD condition). In Study 1, 48 mothers read a storybook to their infants aged 3, 9, 13, or 20 months or an experimenter. In Study 2, 11 mothers read a storybook to their child with a cochlear implant at 3 months post-implantation or to an experimenter; each hearing-impaired child was paired two normal-hearing dyads based on the hearing-impaired child’s chronological age and amount of hearing experience. ID speech contained a greater density of pitch accents and prominences than AD speech. There was no difference in distributions of phrase boundaries across speech styles, and hearing status did not mediate effects of speech style on prosody. Results suggest that acoustic differences distinguishing ID and AD speech map onto combined phonological structural and gradient paralinguistic characteristics and contribute to understanding effects of child hearing loss on caregiver input. [Work supported by NIH Grant 5R01DC008581-07.]
The perception of speech rate in non-manipulated, reversed and spectrally rotated speech reveals a subordinate role of amplitude envelope information
Authors: Dellwo Volker , Schwab Sandra
Published: June 2017

Previous research suggests that the broad-band amplitude envelope (ENV) of speech is crucial for the perception of speech rate and timing. The present experiment tested this claim using non-manipulated and spectrally rotated speech (rotated around 2.5 kHz) with a bandwidth of 5 kHz which both contain identical ENV and reversed speech in which the temporal organisation of ENV is distorted. 44 listeners of Swiss German rated perceived speech tempo on a continuous scale reaching from “rather slow” to “rather fast” in 48 stimuli (4 sentences × 4 speakers × 3 signal conditions). Results revealed a significant effect of signal condition. Both reversed and spectrally rotated speech were perceived as significantly faster than clear speech but there was no difference between spectrally rotated and reversed speech. Results were consistent for all sentences and speakers. Results suggest that the intelligibility of the signal plays a higher role in the perception of speech rate than the presence of the ENV.
Influence of beat phenomenon on direction of arrival estimation based on a single vector hydrophone
Authors: Liu Hongning , Zheng Yi , Mao Yufeng , Yu Yanting , Gong Xiaodong
Published: June 2017

The vector hydrophone can measure sound pressure and orthogonal components of particle velocity co-locately in space and simultaneously in time. DOA (direction of arrival) estimation based on a single vector hydrophone has attracted extensive attention. Beat phenomenon can cause confusion in the DOA estimation results. In this paper, the impact mechanism of beat phenomenon to DOA estimation by cross spectrum method and average acoustic intensity method is explored through theoretical study and simulation. The result shows that beat phenomenon causes the change of sound pressure and vibration velocity amplitude with time and leads to DOA estimation results of these two methods are instability eventually. First, DOA is estimated by the average sound intensity method, if the temporal resolution is smaller than the minimum envelope period, the DOA estimation will change over time; Second, DOA is estimated by the cross spectral method, if the FFT frequency resolution is greater than frequency difference, it is unable to distinguish the frequency of these two signals. Subsequent operations will also be confused by two signal energy, causing error estimates. In the end, the solutions and application examples are proposed. The conclusion could be applied to improve the DOA estimation performance of a single vector hydrophone.
Design of a microphone array for near-field conferencing applications
Authors: Thomas Pieter , Verburgh Reinout , Catrysse Michael , Botteldooren Dick
Published: June 2017

Microphone arrays are becoming increasingly popular for conferencing applications and near-field speech recording. In this work, a 16-element cylindrical microphone array is designed for beamforming toward a nearby speaker, while reducing the influence of competing talkers. A two-stage approach is used to obtain the desired array directivity pattern, optimizing both microphone locations and filter weights. The positions of the microphones are optimized by using a hybrid optimization technique, taking into account the influence of the nearby acoustic environment (array shape and conferencing desk). FIR filter coefficients for each microphone are derived from a regularized least-squares (LSQR) solution, combined with null-steering. An implementation of the array is made with digital MEMS microphones and the performance of the design is evaluated experimentally and compared with a classically used goose-neck microphone.
Sonar technology and underwater warfare from World War I to the launch of USS Nautilus in 1954, the first nuclear submarine
Authors: Hackmann Willem D.
Published: June 2017

Sonar research began in the First World War to curb the U-boat menace. Radical methods had to be devised both organizationally and technically to combat this new form of warfare. Civilian scientists were drafted into naval research. A new field of science was created: underwater acoustics for passive listening, and ultrasonic echo-ranging for active detection of submarines. If the war had lasted only a few more months, prototype Asidic equipment (the Royal Navy’s name for sonar) would have gone operational. During the interwar years the American and Royal Navies developed their sonar “searchlight” systems, while before 1935 the German Navy concentrated on sophisticated passive listening arrays (incorporating American WWI research) to protect their capital ships from enemy submarines. Searchlight sonar technology evolved sharply in WWII. The nuclear submarine in 1954 required a complete rethink of the sonar scanning techniques developed over the previous 40 years. This lecture is based on full access to naval documents and interviews with scientists involved in this work in Britain and the USA for my book Seek and Strike (HMSO, 1984).
Three-dimensional acoustic scattering in highly geometrically constrained environments
Authors: Lucifredi Irena , Nagem Raymond J.
Published: June 2017

For active sonar systems, transmission Loss (TL) and reverberation level (RL) are key parameters derived from the acoustic fields predicted by models and used to assess sonar performance. The existing propagation and scattering models may be appropriate for applications in the deep ocean or open littorals, but sonar operators are increasingly being asked to perform tasks including navigation or detection in significantly more confined waterways such as rivers or ports. Physics-based models are generally not available for predicting the acoustic field in such highly geometrically constrained and dynamic 3D environments often characterized by highly variable azimuthal boundaries such as irregularly shaped port geometries, piers, and breakwaters that may also have high large tidally driven depth variations over short time periods. They also may be populated with large scattering objects such as deep draft vessels and mooring dolphins. A virtual source research model capable of predicting the three-dimensional field, including propagation, scattering, and reverberation in such complex underwater environments is presented here. A complex, variable geometry, harbor scenario containing a large scattering object such as a vessel hull has been modeled in order represent the resultant acoustic field and to investigate scattering mechanisms present. [Work supported by ONR.]
Scattering from objects buried in sandy sediments using a fully scattered field finite element approach
Authors: Bonomo Anthony L. , Isakson Marcia J.
Published: June 2017

The finite element method is utilized to study the scattering response from objects buried in a homogeneous sand half-space. An approach is adopted where the total field is separated into contributions due to the incident, reflected, transmitted fields in the absence of the buried object and the scattered field due to the presence of the buried object. Since the incident, reflected, and transmitted fields can be determined analytically for the case of a flat water-sediment interface, only the scattered field needs to be solved for numerically. This approach results in much faster run times while reducing spurious reflections from the boundaries of the computational domain. The buried object and the sediment half-space can be treated as fluid, viscoelastic, or poroelastic. [Work supported by ONR, Ocean Acoustics.]
Kirchhoff approximation for scattering from solid spheres at flat interfaces: Improved description at large grazing angles
Authors: Gunderson Aaron M. , Marston Philip L.
Published: June 2017

The Kirchhoff approximation has previously been used to model scattering from partially exposed elastic spheres breaking through a flat interface, with variable exposure level, grazing angle, and frequency [J. Acoust. Soc. Am. 136, 2087 (2014)]. The limits of the Kirchhoff integral are determined by the boundaries of illumination on the sphere for each scattering path. Recent adaptations to the methods of boundary determination within the Kirchhoff approximation have yielded faster numerical integration algorithms and higher similarity of results when compared to experimental scattering data and the exact solution at half exposure [J. Acoust. Soc. Am. 140, 3582-3592 (2016)]. Additional steps have been taken to account for the partial blocking of the interface by the partially exposed sphere, through inclusion of a new correction term. This correction is largest at high grazing angles, low frequencies, and low target exposures, and drastically improves the Kirchhoff approximation within these limits. [Work supported by ONR.]
Bistatic scattering from underwater elastic spheres and cylinders: Interference and resonance phenomena
Authors: Gunderson Aaron M. , Espana Aubrey L. , Marston Philip L.
Published: June 2017

Scattering by underwater elastic spheres and cylinders is considered over a full range of scattering angles. Three models are presented in the frequency domain: an exact solution for scattering from an elastic sphere, a finite cylinder approximate solution, and a finite element simulation for the finite cylinder. Close agreement between the two cylinder models speaks to the strength of the finite cylinder approximate solution. Within each model, the dependence of the scattering on frequency and angle is discussed. Resonance structure is highlighted, and families of ridges and valleys in the data can be described by interference models between near-side and far-side Rayleigh paths and the specular reflection. A thorough understanding of bistatic scattering from elastic targets is helpful for data acquisition from moving sources (such as an AUV) or acoustic arrays, as well as studying monostatic scattering from targets at an interface, where the interface may direct bistatic paths to the receiver. [Work supported by ONR.]
Effect of nonlinear internal wave on monostatic reverberation in the shallow water region with underwater sound channel
Authors: Park Jungyong , Choo Youngmin , Seong Woojae , An Sangkyum
Published: June 2017

The effect of nonlinear internal wave on reverberation is investigated for the shallow water region having an underwater sound channel, which was observed during SAVEX15 experiment. When source is located near the channel axis, the reverberation from rough bottom is insignificant because of trapped modes not interacting with the bottom. However, when a nonlinear internal wave is present, the reverberation level increases since trapped modes transfer to bottom interacting modes due to sound fluctuation by the nonlinear internal wave. This trend can be explained by the coupled mode equation [(2014). J. Acoust. Soc. Am. 135, 610-625]. To theoretically describe the increase of bottom reverberation, we simplify the situation where two modes are present; one is a trapped mode and the other is bottom interacting mode. In the situation, the trapped mode transfers to the bottom interacting mode after its encounter with the nonlinear internal wave. The bottom reverberation has different patterns and levels before and after the internal wave, and thus, it highly depends on the distance between source/receiver and internal wave.
Benefiting from Bertram Kinzey's legacy
Authors: Madaras Gary
Published: June 2017

In 1991, when I rolled into Gainesville, FL, to begin doctoral studies at the University of Florida's Department of Architecture, I did not know who Bertram Kinzey was. I did not realize that he was actually the reason that I, and a first wave of doctoral students, could study architectural acoustics in the United States. I entered an academic environment that had a solid and broad foundation in architectural acoustics ~ scale models, instrumentation, custom acquisition software, room acoustic measurement and subjective survey databases and faculty relationships throughout the university. This platform was part of Bertram Kinzey's legacy. I will review how I, and many others, benefited from it during our studies at the University of Florida and since then in our careers.
Unusual architectural spaces and the challenges they present to musicians and performance artists
Authors: Plsek Thomas J. , Rice Joanne G.
Published: June 2017

For almost 15 years, trombonist Tom Plsek and performance artist Joanne Rice have been exploring the notion of sound and visual performance in spaces not conducive to any normal practices. This presentation will focus on the acoustics of two very different spaces, the abandoned quarries in Quincy, Massachusetts, and the 808 Gallery at Boston University, a 16,000 square foot rectangular space with tall ceilings, and how practices were developed to create performances under what most would consider very challenging environments.
The room they want to hear: Subjective preference of reverberation in vocal recordings
Authors: Lysoivanov Yuri
Published: June 2017

Audio professionals in the digital era have hundreds of reverberation options at their disposal, from the uber-realistic to the dynamic and creative. Often the choice of reverb is made with a set of heuristics—based on the engineer’s experience and opinion for what achieves the best musical and dramatic effect. In this presentation, we turn to the listener and explore their preferences of reverberation on vocal performances. Through a series of experiments, we evaluate the aesthetic preferences of the casual music consumer and compare them to those of the experienced audio engineer. In addition, we examine factors that may predispose listeners to prefer certain reverberation characteristics over others.
Sound reinforcement for a divisible auditorium
Authors: Britton Deb , Hodsgon Kevin , Foster Gain
Published: June 2017

As part of an audiovisual renovation to a conference center, one particular space, an auditorium that can be divided into four separate spaces, posed a particular sound reinforcement challenge. This paper describes the architecture of the space, its various uses, and presents our approach to providing flexible, yet high-quality sound reinforcement.
Comparison of sound isolation performance of floor/ceiling assemblies across structural systems
Authors: Markham Benjamin
Published: June 2017

The recent building boom in greater Boston has given rise to multifamily buildings utilizing a wide range of structural systems, including cast-in-place concrete, pre-cast concrete, steel, heavy timber, and various wood frame structural systems. Both laboratory and field measurements indicate that typical floor/ceiling assemblies utilized with each structural system have certain characteristic acoustical attributes. Although these assemblies perform differently, virtually all of these structural systems have been utilized in buildings advertising “luxury” residential living. This presentation compares recently obtained sound isolation data among the various structural types. Specific acoustical design challenges and constraints (such as budget, available floor-to-floor height, and others) are identified, and guidelines for achieving sound isolation commensurate with a “luxury” standard are outlined for each of the structural systems examined.
Environmental vocalization adaptation: Animals compensating for restricted visibility and mobility
Authors: Browning David , Herstein Peter
Published: June 2017

To survive, animals must always be aware of their surroundings and they adopt different communication strategies to adapt to changing environmental conditions. This paper describes some vocalization adaptations. Horses in open pasture usually communicate visually but when placed in separate barn stalls, with restricted visibility and mobility, must rely more on their vocalizations, referred to as barntalk. In addition they rapidly learn to recognize sounds from unseen objects of interest such as a feed cart or their owner. In some cases animals utilize a new vocalization, Asiatic wild dogs (Dholes) have developed a short whistle to keep contact among their hunting pack when visibility is reduced by underbrush, while not interfering significantly with listening for their prey. Nowhere is there more vocalization adaptation than in a jungle, with limited visibility, difficult mobility, and the added complication of many other competing sounds. As a result Sumartran rhinos have developed a far more complex vocalization than their African relatives on the open plains. An interesting variety of jungle vocalization strategies have developed, from the Tapirs sweeping whistles to the toned howls of New Guinea singing dogs.
Sound speed and attenuation in water-saturated granular materials at MHz frequencies
Authors: Hare Jenna , Hay Alex E.
Published: June 2017

Sound speed and attenuation measurements are reported for water-saturated granular materials (natural sand and glass beads) at frequencies of 1.0 to 1.8 MHz. Median grain diameters were 0.219 to 0.497 mm, corresponding to kd>1, i.e., the scattering regime. The measurements were made for different thicknesses of sediment resting on a reflective surface using a monostatic geometry. The attenuation estimates compare well with previously reported experimental results and to the predictions of multiple scattering theory. The sound speed estimates exhibit the negative dispersion predicted by theory, but compared to previous measurements are biased low by 100 m/s to 200 m/s. It is argued that this bias is due to microbubbles in concentrations of O(10) ppm by volume.
Transient reflection from mud during molecular diffusion of salt
Authors: Venegas Gabriel R. , Wilson Preston S.
Published: June 2017

Harbor basins and estuarine environments experience drastic salinity fluctuations in the water near the water-sediment interface, which can significantly affect how sound interacts with a low-velocity mud bottom. This presents challenges in applications including mine detection, port protection and shallow water sonar. In a previous investigation of this system, a mud sample that was saturated with fresh water was instantaneously exposed to salt water. Laboratory measurements of plane wave reflection from the water-mud interface were obtained using a time-gated broadband impulse as time evolved. Results suggested molecular diffusion of salt into the sample had altered the reflected pulse’s amplitude and caused a depth-dependent impedance profile in the mud. The sediment was discretized into layers much thinner than a wavelength and a multi-layer steady-state model was used to predict the reflection from the diffusing mud. As the effective diffusion length reached a critical value, predictions of the steady-state model began to deviate from the measurements, indicating that a transient solution was required. A model of the transient reflection of a finite-length pulse from a half space with an arbitrary impedance will be presented and model results compared with laboratory measurements. [Work supported by ONR.]
Influence of sand/silt particle size distributions on compressional wave attenuation in marine mud sediments
Authors: Brown Elisabeth M. , Pierce Allan D. , Siegmann William L.
Published: June 2017

High porosity marine mud from different sites typically contains different amounts of clay, sand, and silt particles, along with other material. A recent talk [Pierce et al., ASA Honolulu, 5aAO1 (2016)] explored a mechanism for why sand and silt particles in suspension can provide the dominant contributions to the frequency dependence of compressional wave attenuation. The card-house structure of the clay is critical in supporting the particles and keeping them separated. Example calculations for spherical particles of the same size showed physically reasonable attenuation behavior at low and high frequencies. This presentation considers extensions of the approach, particularly accounting for distributions of particle sizes, and emphasizes comparisons of attenuation predictions with available field data. Using reasonable assumptions about the clay volume and the sand and silt distributions, it is possible to estimate the numbers of sand and silt particles, and consequently the attenuation, from the sediment porosity. Such results can be compared with measurements of attenuation frequency dependence for measured porosities, in order to validate or refine the model for the mechanism. Of specific interest is determination of the frequency bands over which the attenuation increases nearly linearly with frequency, as is often estimated or assumed. [Work supported by ONR.]
Role of clay particle electrostatics and the dielectric permittivity of suspended silt particles in sound attenuation in mud
Authors: Pierce Allan D. , Siegmann William L. , Brown Elisabeth M.
Published: June 2017

Sound attenuation in marine mud sediments is partly caused by viscous dissipation of acoustically induced flow past suspended silt particles. Clay particles in the surrounding lattice carry electrostatic charges, causing high porosity, so one asks why silt particles do not settle because of gravity to the bottom of the mud layer. Explanation of the suspension and the associated attenuation of sound proceeds from consideration of a quartz sphere immersed in mud. The somewhat-random electric field created by the clay particles causes an electric dipole moment to arise in the sphere because of its dielectric permittivity. This is proportional to the electric field and varies with position, and the result is an electrostatic force on the sphere, the force being proportional to the gradient of the electric field. In equilibrium, this force is balanced by a gravity force. There is a natural spring constant associated with deviations from equilibrium, and the resulting dynamical model is a fixed-mass sphere subjected to a spring force, the force of gravity, and the viscosity-associated force caused by the motion of the surrounding fluid and the no-slip condition at the sphere’s surface. Paper quantitatively discusses the model’s implications on the suspension theory of sound attenuation. Results suggest approximate validity for representative acoustic frequencies of model where sphere has same density as water. [Work supported by ONR.]
Assessing the effect of lithotripter focal width on the fracture potential of stones in shockwave lithotripsy
Authors: Cao Shunxiang , Zhang Ying , Liao Defei , Zhong Pei , Wang Kevin G.
Published: June 2017

This talk presents a combination of computational and experimental study on the effect of lithotripter focal width on the fracture potential of stones treated at various distances from the lithotripter focus. Two representative lithotripter fields are considered: (1) the original Siemens Modularis with a focal width of 7.4 mm and (2) a modified version with a larger focal width of 11.0 mm with comparable acoustic pulse energy of 40 mJ. The interaction of these two lithotripter fields with spherical and cylindrical model stones located at 0 to 12 mm from the shock wave axis is investigated. Specifically, a three-dimensional CFD (Computational Fluid Dynamics)—CSD (Computational Solid Dynamics) coupled computational framework is used to simulate the propagation of stress waves, as well as the initiation and propagation of fractures. The two-scale Tuler-Butcher fracture criterion will be employed: it will be calibrated experimentally, then applied to assessing stress-induced stone damage. An element deletion method will be applied to simulate fracture. Characteristic changes in wave focusing and interference in relation to the buildup of the maximum tensile stress inside the stone will be presented. The physical mechanism(s) responsible for the different fracture patterns observed at different off-axis distances will be discussed.
A multi-element HIFU array system: Characterization and testing for manipulation of kidney stones
Authors: Ghanem Mohamed A. , Bailey Michael , Maxwell Adam D. , Cunitz Bryan , Kreider Wayne , Hunter Christopher , Khokhlova Vera , Sapozhnikov Oleg A.
Published: June 2017

Most progress in acoustic trapping and levitation has been achieved with the use of multiple sound sources, standing waves, and low density or very small objects. Repositioning kidney stones in the human body is an important clinical application where acoustic levitation could be employed; however, it requires manipulation of larger and heavier objects. The goal of this work was to calibrate the acoustic output of a 1.5-MHz, 256-element array designed in our laboratory for HIFU research, which is also capable of generating vortex beams to manipulate mm-sized objects in water and to move them in any direction without moving the source. Electrical circuits were developed for matching each element of the array to an output channel of a Verasonics ultrasound engine to allow for efficient power transfer to the transducer. Acoustic holography was used to calibrate and equalize outputs across all channels. Manipulation of artificial kidney stone targets made of plastic, glass, or cement (2—8 mm) and comparable in size to or larger than the wavelength in water by electronic steering of the vortex beam lateral to the acoustic axis was demonstrated. [Work supported by NIH P01 DK043881, K01 DK104854, R01 EB007643, and NSBRI through NASA NCC 9-58.]
The acoustic field of a spherical self-focusing Eisenmenger electromagnetic shockwave source (EMSE)
Authors: Jamshidi Rad Abtin , Ueberle Friedrich
Published: June 2017

Shockwave sources are used in extracorporeal lithotripsy, pain therapy and a wide range of other medical applications. Typical lithotripter source pulses mostly achieve positive pressure amplitudes of ca. 35 to 100 MPa and tensile pressures amplitudes up to -20 MPa. Already 1962, Eisenmenger designed a plane electromagnetic source, which was further developed into a spherically shaped, self-focusing electromagnetic source (ca. 1991). We have one of his prototype sources (Membrane diameter 120 mm, focal distance 200 mm), which was measured according to the standard IEC61846. Focus and field measurements were done using a single-spot fiberoptic hydrophone and compared to a multi-spot optical hydrophone. Very low variations of the acoustic output were found (for the peak positive pressure and for the energy). Notably, in contrast to many other shockwave sources, the spherical EMSE provides steep shockwaves (10...20 ns risetime) in the focus at comparably low pressures (33...36 MPa), even at lower energy settings. Peak negative pressures were in the range of < -10 MPa. Focus and field measurements show the interesting properties of the spherical self-focusing EMSE, also in comparison to stronger focusing setups.
Nonlinear elasticity imaging with dual frequency ultrasound
Authors: Kvam Johannes , Solberg Stian , Brende Ole Martin , Myhre Ola Finneng , Rodriguez-Molares Alfonso , Kongsro Jørgen , A.J. Angelsen Bjørn
Published: June 2017

Elasticity imaging has shown to enhance diagnostic capabilities of disease as tissue elasticity is often associated with pathological condition. Methods such as Acoustic Radiation Force Impulse imaging and Supersonic Shear Wave imaging have shown good results at shallow depths. Second-order ultrasound field (SURF) imaging is a dual band imaging technique that utilizes a low frequency (LF) pulse to manipulate the nonlinear elasticity of the medium observed by a co-propagating high frequency pulse (HF). The manipulation of the material parameters causes the HF to experience a change in propagation velocity which depends on the manipulation pressure and nonlinear elasticity of the medium. The change in propagation velocity causes an accumulative delay or advancement compared to a single HF pulse, called the nonlinear propagation delay (NPD). By transmitting multiple pulse complexes with different LF polarities the technique has proven capabilities for suppression of multiple scattering noise. By observing local variations in the development of NPD, it is possible to estimate the nonlinear elasticity variation of the medium. Simulations with k-Wave toolbox have shown the methods feasibility, also at greater depths. In-vitro and in-vivo experiments have also yielded promising results.
An ultrasound surface wave elastography technique for noninvasive measurement of surface lung tissue
Authors: Zhang Xiaoming , Osborn Thomas , Zhou Boran , Bartholmai Brian , Greenleaf James F. , Kalra Sanjay
Published: June 2017

Ultrasonography is not widely used in clinic for lung assessment because ultrasound cannot image deep lung tissue. In this abstract, we present a novel technique, lung ultrasound surface wave elastography (LUSWE), for measuring the elastic properties of superficial lung tissue. In LUSWE, a small, local, and 0.1 second harmonic vibration is generated on the chest of a subject. The speed of surface wave on the lung is measured by using an ultrasound probe. We are evaluating LUSWE for assessing patients with interstitial lung disease (ILD). LUSWE may be useful for assessing ILD because most ILD patients have typical fibrotic scars in the peripheral and subpleural regions of the lung. In a large clinical study of ILD patients, we measure both lungs through six intercostal spaces for patients and controls. The surface wave speed is measured at 100 Hz, 150 Hz, and 200 Hz. In an example, the surface wave speed is 1.88 ± 0.11 m/s and 3.3 ± 0.37 m/s, respectively, for a healthy subject and an ILD patient at 100 Hz and in the same intercostal space. LUSWE may compliment the clinical standard high-resolution computed tomography for assessing ILD. LUSWE may be useful for assessing other lung disorders.
MEMS-Based acoustic sensors for fluid mechanics and aeroacoustics
Authors: Sheplak Mark
Published: June 2017

This talk presents the development of several microelectromechanical systems (MEMS)-based acoustic transducer technologies for fluid mechanics and aeroacoustics applications. Specifically, this presentation will focus on several aluminum nitride piezoelectric MEMS dynamic pressure sensors and microphones. These devices offer the promise of reducing cost, improving performance, and increasing mounting flexibility over existing conventional microphone technologies. Specifically, a transducer with no external power requirement has a key advantage for a large-channel count, widespread deployment. The modeling and design aspects of these devices are reviewed. First, the electroacoustic transduction is predicted via piezoelectric composite plate theory. Lumped element models are then synthesized to describe the dynamic characteristics of the transducer diaphragm and the cavity/vent structure. Constrained nonlinear design optimization using a sequential quadratic programming scheme is then performed to determine the design parameters. Representative results for several applications will then be presented. Finally, unresolved technical issues are summarized for future sensor development.
MEMS resonant acoustic wake-up sensor
Authors: Bernstein Jonathan , Bancu Mirela , Reilly Daniel , Weinberg Marc , Gauthier Doug , Elliot Richard
Published: June 2017

Draper has built zero-power MEMS wake-up sensors for DARPA’s N-ZERO Program. This program aims to enable unattended sensor arrays that last for years, limited only by battery discharge rates. For some targets, characteristic frequency signatures allow detection using narrow band passive acoustic resonators. The MEMS sensors use ambient acoustic inputs to actuate a wake-up electrical relay. Resonant sensors from 30 Hz to 180 Hz have been fabricated. The device rotates in response to an acoustic input, thereby avoiding large displacements due to gravity which would occur with a linear actuator. An adjustable acoustic cavity designed as part of the package is used to tune the resonant frequency to match a particular target. FEA Modeling was performed to achieve desired spring constants and resonant frequency. A rotary-acoustic lumped element equivalent circuit model was used to analyze the effect of the cavity and leakage resistances on the device performance. We will show finished MEMS devices and acoustic test data. [This research was developed with funding from the Defense Advanced Research Projects Agency (DARPA).]
Sensing sound with a nanoscale fiber
Authors: Miles Ronald , Zhou Jian
Published: June 2017

A feasibility study is presented of the use of a thin fiber to detect sound. The fiber is assumed to be supported on each end, with a deflection in response to a sound wave that propagates in the direction perpendicular to its long axis. The driving force on the fiber is the result of viscous forces in the oscillating air, which are well-known to be very important in determining the flow-induced motion of small structures. A simplified analytical model of the fiber's response is presented where it is argued that for fibers that are sufficiently thin, elastic and inertial effects become strongly dominated by viscous forces in the fluid. As a result, the fiber's motion becomes a very close approximation of that of the acoustic flow in its vicinity. Electrodynamic transduction of the fiber's motion provides a means of sensing sound with remarkable accuracy if the fiber diameter is taken to be measurably below one micron.
A perceptually orientated approach for automatic classification of timbre content of orchestral excerpts
Authors: Antoine Aurelien , Miranda Eduardo
Published: June 2017

In this paper, we report on the development of a perceptually orientated and automatic classification system of timbre content within orchestral audio samples. Here, we have decided to investigate polyphonic timbre, a phenomenon emerging from the mixture of instruments playing simultaneously. Moreover, we are focusing on the perception of the entire orchestral sound, and not individual instrumental sound. For accessibility to non-Acoustics experts, we chose to use verbal descriptors of timbre quality, such as brightness and roughness, to represent the timbral content of the samples. We based our acoustic analysis on the existing research into the perception and description of timbre. However, with a lack of agreed metrics, we had to establish a comparative scale for each timbre attribute implemented in our system, which is based on an analysis of audio recordings, in order to identify the dominant timbral attribute. To improve the classification accuracy, the system continually calibrates this scale as new audio files are analyzed. Preliminary analysis of our results shows a correlation between the system’s classification and human perception, which is promising for further developments, such as standardizing metrics for perceived responses of timbral attributes or implementing systems for music production tasks.
Numerical study of nonlinear distortion of resonant states in acoustic tubes
Authors: Velasco-Segura Roberto , Rendon Pablo L.
Published: June 2017

A numerical study of nonlinear acoustic propagation inside tubes is presented. Thermoviscous attenuation is included, giving rise to wall losses associated with the boundary layer. The full-wave simulation is performed in the time domain, over a 2D spatial domain assuming axial symmetry, and it is based on a previously validated open source code, using Finite Volume Method implemented in GPU (FiVoNAGI) [Velasco & Rendón, A finite volume approach for the simulation of nonlinear dissipative acoustic wave propagation, 2015]. One intended application is the identification of resonance frequency shifts in the nonlinear regime in brass musical instruments as a function of bore profile and amplitude of the driving stimulus. To gain insight on the nonlinear processes taking place inside the tube, visualizations are presented, differentiating spectral components and traveling waves in both directions.
On a sound analysis of Korean Trot singer Nam in-su’s voice
Authors: Kim Bong Young , Ann Ik-Soo , Bae Myungjin
Published: June 2017

The word “‘trot” means “walk quickly” and the fox-trot, which refers to the performance rhythm of social dance and it is now being used as a word relating to musical genre and performance. The late singer Nam In-su was Korean who performed in the early stage of Korean trots, and he had sung about 1,000 songs for about 20 years since his debut in 1938. His representative songs are “Sorrowful Serenade” (1938), “Vanish Away, the 38th Parallel (the Cease-fire Line of the Korean War)” (1949) and “Parting at Busan Station” (1953). His songs consoled Korean people against the sorrow of a lost and colonized home country and healed the pain generated from the division between South and North Korea and the loss due to the Korean war. This paper analyzes the acoustic components of his vocal voice that induce the softness and liveliness. His voice crosses over three octaves, and even when he sings quickly, his high-pitched sound spreads wide. The sound connection between measures is natural and smooth. In addition, deep vibrations appear at all frequency bandwidths, and pronunciations of lyrics are accurate, so his voice sounds very lively. This study will be helpful in understanding the value of popular singers’ vocal voice supported with acoustic analysis.
Comparison of classification of musical genre obtained by subjective tests and decision algorithms
Authors: Dorochowicz Aleksandra , Majdańczuk Agata , Hoffmann Piotr , Kostek Bozena
Published: June 2017

The aim of the study is to conduct subjective tests on audio excerpt assignment to music genre and to carry out automatic classification of musical genres with the use of decision algorithms. First, the musicology background of classifying music into styles and genres is discussed. Then, an online survey is created to perform subjective tests with a group of listeners, whose task is assigning audio samples to selected music genres. Next, a set of music descriptors is proposed and all music excerpts are parametrized. For checking parameter redundancy the Principal Component Analysis (PCA) is performed. The created database containing feature vectors is then utilized for automatic music genre classification. Two classifiers, namely: Belief Networks and SMO (Sequential Minimal Optimization Algorithm) are employed for the purpose of music genre classification. The last step of this study is to compare the efficiency of the listeners classification with the automatic music genre classification system designed by the authors. Conducted tests show to what extent listeners’ assignment and the automatic classification results agree. It is also observed that very known performers are often rated without problems. Contrarily, songs of less known artists are more difficult to assign to the given genre.
Estimating community tolerance for wind turbine noise annoyance
Authors: Keith Stephen , Michaud David
Published: June 2017

A-weighted WTN contributed less than 10% to the strength of the multiple regression model developed for wind turbine noise (WTN) annoyance in Health Canada’s Community Noise and Health Study (CNHS). Improvements required consideration of non-LAeq variables unknown or even inapplicable beyond the CNHS. To facilitate cross-study comparisons, an analysis of WTN annoyance was conducted based on the community tolerance level (CTL) model. The rate of increase in WTN annoyance was effectively estimated using a loudness function, as shown in Eq. (1). %HA = 100 exp (-(1/[10((DNL-CTL + 5.306)/10)]0.3)). (1) By convention, CTL is the DNL from Eq. (1) where 50% of the community would be highly annoyed. The CTL for WTN annoyance from field studies published to date ranges from 57.1 to 64.6 DNL (mean = 62, σ = 3). CTL values developed by others for transportation noise sources suggest that, on average, communities are between 11 dB and 26 dB less tolerant of WTN than of other sources, depending on the source. Confidence in these results should increase as future studies in this area produce additional estimates for the relationship between WTN level and the prevalence of high annoyance. The CTL analytical methods, assumptions, strengths, and limitations are presented.
CTL—A useful tool for inter-survey comparisons
Authors: Gjestland Truls , Gelderblom Femke B.
Published: June 2017

The concept of Community Tolerance Level was presented in 2011 and in subsequent analyses the CTL has proven to be a useful tool for comparing results from different surveys on noise annoyance. The CTL provides a robust single-number description of the prevalence of annoyance in a community noise survey. It has been shown that accurate predictions of the prevalence of highly annoyed residents can be achieved by relatively few survey interviews as the selection of respondents does not have to cover the whole range of exposure. A re-analysis of existing studies on aircraft noise annoyance has shown that there has been virtually no change in people's response to this type of noise over the past 50 years, but there is a distinct difference in the response depending on the rate of which the noise situation has been changing. A similar analysis of results on road traffic noise from surveys conducted over a period of more than 50 years, will be presented.
Evaluation of a calculation method of noise exposure from communication headsets
Authors: Dajani Hilmi R. , Nassrallah Flora G. , Chabot Caroline , Ellaham Nicolas N. , Giguère Christian
Published: June 2017

Specialized standardized methods for the measurement of noise exposure from communication headsets or sound sources close to the ear include the Microphone in Real Ear and manikin techniques, as specified in ISO 11904-1/2. The 2013 version of Canadian standard Z107.56 introduced a simpler calculation method to increase accessibility to communication headset exposure assessments for the widest range of stakeholders in hearing loss prevention. The calculation method only requires general and widely accessible sound measurement equipment and basic computational steps that account for the main determinants of exposure such as the background noise around the user, the sound attenuation of the communication headset, and the expected communication duration and effective listening signal-to-noise ratio. This paper reviews recent research on the effects of the spectral and temporal characteristics of the background noise and the headset configuration on the speech listening level. Results indicate that the listening level is largely insensitive to spectral and temporal variations in the background noise and that A-weighted noise level is a good predictor of listening level once headset attenuation is taken into account. It is also found that one-sided headsets increase exposure by 6-7 dB compared to two-sided headsets due to binaural summation.
Real-time estimation of the passive attenuation for otoacoustic emission measurement probes
Authors: Nadon Vincent , Voix Jeremie
Published: June 2017

Despite hearing loss prevention programs in place at work, noise-induced hearing loss (NIHL) remains the first reported occupational disease. To improve the detection of over-exposure to noise, an initial proof-of-concept for field monitoring of inner-ear health using otoacoustic emissions (OAE) was developed and successfully validated in laboratory conditions. However, in real-life situations, the unsupervised placement of the OAE probes remains a challenge: proper fit of the probe in the ear canal is required to ensure adequate hearing protection of the wearer, to improve the signal-to-noise ratio of OAE measurements and to maintain the proper calibration of stimuli signals in the case of the Distortion Product OAE (DPOAE) approach used. Algorithms were recently developed to quantify, in real-time, from the OAE probe microphones and receivers signals, the passive attenuation of the OAE probes. The validation of this approach was conducted, in laboratory conditions, on five human subjects exposed to industrial and pink noise recordings at realistic levels.
Quiet rim driven ventilation fan design
Authors: Hurtado Mark P. , Wu Daniel , Burdisso Ricardo
Published: June 2017

Auxiliary ventilation fans are commonly used as a form of temperature and humidity control of working environments. However, they often generate high noise levels that cause permanent hearing impairment from prolonged exposure. Dominant noise sources from ventilation fans such as noise due to the aerodynamic interaction of the fan with the struts to support the hub motor and the blade-duct tip gap can be eliminated using a rim driven fan. However, tones from blade steady loading and thickness and the broadband airfoil self-noise of the fan are not eliminated. This noise is proportional to the 4-6th power of the tip speed. Hence, the approach here is to design a ring driven ventilation fan that reduces the fan tip speed while optimizing the blade profile to retain aerodynamic performance. The fan design has been 3D printed and implemented using a motor mounting system to validate the predicted performance. The motor mounting system integrates the fan design, a bell mouth shaped duct and a brushless DC motor. The experiments show good agreement with the predicted mechanical power, axial flow, and radiated noise over a range of speeds. Results suggest that a ring driven fan reduces noise while maintaining aerodynamic performance.
Social benefit analysis of reduced noise from electrical city buses in Gothenburg
Authors: Larsson Krister , Holmes Maria
Published: June 2017

The city of Gothenburg is the second largest city in Sweden and has an ambitious traffic strategy to increase the share of public transport substantially until 2035. At the same time the city is growing due to urbanization and the densification of the city leads to an anticipated growth in city bus traffic. However, noise from buses might lead to negative consequences for the citizens and electrical buses could be a way to reduce noise and emissions from the public transport system. In this study a comparison of noise levels and social costs of bus types with different powertrains are presented. Initially, noise emissions from three bus types were measured on a test track. The propulsion noise was extracted and coefficients for the Nord2000 Road prediction model were adapted. The Nord2000 model was used to calculate façade noise levels in the city center, as well as in a smaller focus area. The predicted noise levels were used to calculate health effects according to DALYs, as well as social costs according to ASEK. In addition, indoor maximum noise levels were calculated for typical façade cases based on the measurements. The results show that the largest benefits from electrical buses are obtained during acceleration, for example, at bus stops, and for maximum levels indoors. However, these situations are not taken appropriately into account in current social cost models.