bluuebunny/crossref_metadata_2025 huggingface dataset:
The healthcare acoustics research team: Bridging the gap between architecture, engineering, and medicine
Authors: Ryherd Erica , Ackerman Jeremy , Zimring Craig , Persson Waye Kerstin
Published: November 2013

Healthy soundscapes are paramount to the missions of hospitals: patients need to sleep and heal without environmental stressors; staff, patients, and family need to communicate accurately but privately; staff need to be able to localize alarms and calls for help. This talk discusses recent findings from the Healthcare Acoustics Research Team (HART), an international, interdisciplinary collaboration of specialists in architecture, engineering, medicine, nursing, and psychology. Members of the HART network are actively engaged in research in the United States and Sweden, having worked in more than a dozen hospitals and a broad range of unit types including adult and neonatal intensive care, emergency, operating, outpatient, long-term care, mother-baby, and others. Highlights will include projects relating noise and room acoustic measures to staff and patient response in addition to studies evaluating impacts of acoustic retrofits. Results show that effective hospital soundscapes require a complex choreography of architectural layout, acoustic design, and administrative processes that is only beginning to be fully understood.
Acoustic comfort in healthcare facilities—What is it? and What does it mean to both patients and medical staff?
Authors: Roy Kenneth P.
Published: November 2013

Acoustic comfort is all about meeting the acoustic needs of the patient, family, professional staff in hospitals, clinics, pharmacies, etc. These needs include low distraction and annoyance for patients to fully enjoy a “healing environment”, high levels of speech intelligibility to support communications and to help reduce medical errors, and adequate speech privacy to meet HIPAA and other privacy needs. How to design for these, and how to verify performance—these are the key issue to be addressed. Architectural choices need to be made with a view for acoustic comfort in addition to all the other relevant design factors. Facility evaluations as part of the commissioning process need to include both objective and subjective surveys to push forward evidence based design approaches for others to take advantage of in future designs. All of these issues are part of the ongoing discussions and field studies that we have been having, and will continue to have.
Analysis of granular hospital sound level measurements
Authors: Davenny Benjamin , Betit Aaron , Yoder William
Published: November 2013

Remote sound monitoring systems were deployed in several locations in a hospital to measure sound levels due to building system and activity noise. In addition to 5 min interval data, granular sound levels were recorded several times per second to provide flexibility in data analysis. Analysis of this information will be presented.
Renovation of neonatal intensive care unit per the Facilities Guideline Institute's 2010 Acoustical Design Guidelines
Authors: Miller-Klein Erik
Published: November 2013

We did an evaluation of the acoustical conditions of the existing neonatal intensive care unit at the St. Joseph's Hospital in Tacoma, Washington, and issued detailed renovation recommendations that were integrated into the final design. At the conclusion of construction, our team was able to evaluate the improvements of the acoustical conditions per the 2010 FGI Guidelines and the original performance. These included noise impacts from door closures, curtains, alarms, and the conversations.
Conservation applications of baseline acoustic tag data from right whales
Authors: Parks Susan , Nowacek Douglas P. , Johnson Mark , Tyack Peter L.
Published: November 2013

Data collected from archival acoustic tags have dramatically improved our understanding of marine mammal subsurface behavior. Some of the earliest tag deployments were made on the endangered North Atlantic right whale (Eubalaena glacialis) to better understand their behavior and to contribute to their conservation. Over the past 15 years, the database of acoustic tag records collected from a diverse cross section of the population has served as a valuable resource for research. Acoustic tag data have provided critical behavioral information including details on individual calling behavior in designated critical habitat feeding grounds, behavioral responses to controlled exposures of acoustic signals including conspecific and man-made signals, acoustic responses to vessel noise, and ground truth data for passive acoustic monitoring efforts. Current studies continue to utilize tag data to shed light on the individual, seasonal, and regional variation in acoustic behavior of right whales, particularly focused on the shallow water coastal habitats of the calving grounds off of Florida and Georgia and in the migration corridor off the Eastern United States. These studies have contributed data that are crucial for targeted conservation efforts and highlight the value of long-term databases of tag data in baleen whale research.
Noise design tradeoffs for a general-purpose broadband acoustic recording tag
Authors: Burgess William C. , Blackwell Susanna B. , Dexter Patrick
Published: November 2013

To design instruments for general-purpose use invokes both blessings and curses; blessings because a flexible product may leverage its development effort across many different applications, but curses because it may not be perfect for any of them. Designing for noise performance of broadband acoustic recording tags epitomizes this tradeoff. Lower self noise typically requires more power and a larger transducer, and may come at the expense of clipping strong sounds, all of which impact tag applications. Higher self noise, however, reduces detection range under quiet conditions and diminishes utility for noise monitoring. The electronic design of the Acousonde™ acoustic/ultrasonic recording tag navigates this challenge using two acoustic channels with very different gains (29–49 versus 14–34 dB), noise (minimum 40 versus 70 dB re 1 μPa2/Hz at 1 kHz), and bandwidths (42 versus 9.3 kHz). Mechanically, design for hydrodynamics reduces turbulent flow noise especially once the tag aligns with flow direction due to self-orienting. As a result of these design elements, the Acousonde's noise performance is comparable to that of a much larger recording instrument while preserving capability as an animal tag. [Development supported by ONR.]
Use of an animal-borne active acoustic tag to conduct minimally-invasive behavioral response studies
Authors: Fregosi Selene , Klinck Holger , Horning Markus , Mellinger David K. , Costa Daniel P. , Mann David A. , Sexton Kenneth , Huckstadt Luis
Published: November 2013

A pilot study was conducted to evaluate the potential of animal-borne active and passive acoustic tags for conducting minimally-invasive behavioral response studies on pinnipeds. A prototype tag was developed and tested on juvenile northern elephant seals (Mirounga angustirostris) using translocation experiments at Año Nuevo State Park, CA, USA, in spring 2012. The principal scientific questions of this pilot study were (1) do low-intensity sounds emitted by an animal-borne tag elicit behavioral responses, and (2) are potential animal responses related to signal content (e.g., threatening vs non-threatening)? Preliminary results indicate that (1) low-intensity sounds emitted by animal-borne tags elicit distinct behavioral responses, (2) these responses appear related to signal content, and (3) the responses may differ based on depth, bathymetry, and location. The results of the study show the promise of this approach as a minimally invasive and cost-effective method to investigate animal responses to underwater sounds, as well as a method to develop mitigation strategies. We are currently in the process of improving the tag design for future field efforts with the goal to increase the sample size, range of acoustic stimuli, and age/sex classes of tagged seals. [Funding from NOAA/NMFS Ocean Acoustics Program.]
Putting tags in the researcher's toolkit: An examination of the strengths, limitations, and added-value from animal tagging
Authors: Gisiner Robert
Published: November 2013

The US Navy, through the Office of Naval Research and other offices, has focused on improving animal tags, reducing cost, and increasing availability. From data-rich packages like video and acoustic dataloggers to simple location-only tags, tags provide a variety of new data to studies of marine animals and their ecosystems. Tags realize their full potential when calibrated or validated against other existing alternative sensor systems like visual surveys, photo-identification, genetics, and acoustic monitoring. When tag cost, cost of delivery and recovery or monitoring are weighed against the data uniquely available from tags, an integrated data collection strategy involving animal tagging can be developed to generate the best data at the optimal total cost for a given research or resource management scenario.
Impact of underwater explosions on cetaceans
Authors: Baumann-Pickering Simone , Debich Amanda J. , Širović Ana , Carretta James V. , Trickey Jennifer S. , Gresalfi Rohen , Roch Marie A. , Wiggins Sean M. , Hildebrand John A.
Published: November 2013

Use of seal bombs to deter sea lions from being caught in nets and preying on catch is a common practice for a number of fisheries. Purse seine fisheries in Southern California target primarily squid, but also scombrids and baitfish such as sardine and anchovy, while set gillnet fisheries’ primary catch are halibut and white seabass. All of these fisheries use seal bombs as deterrents. Continuous passive acoustic recordings at several sites in the Southern California Bight collected since 2007 revealed an extensive use of smaller explosives, most likely seal bombs, during nighttime hours with a seasonal occurrence matching fishery activities. During several months of the year they were used all night, every night. The median occurrence of explosions when detected was 8 per hour; however, during periods of high fishing effort they reached up to 480 explosions per hour. From behavioral response and opportunistic studies we know that beaked whales as well as endangered blue whales react negatively to anthropogenic sound sources. We are testing the hypothesis that these underwater explosions have a suppressive effect on the acoustic behavior and therefore the communication and foraging of cetaceans, possibly leading to impacts on the individual fitness and overall population health.
Ultrasound-targeted delivery of systemically administered therapeutic nanoparticles
Authors: Timbie Kelsie , Burke Caitlin , Nance Elizabeth , Woodworth Graeme , Miller Grady W. , Hanes Justin , Price Richard J.
Published: November 2013

The ultrasound (US)-targeted delivery of systemically administered drug and gene-bearing nanoparticles has emerged to become a robust area of investigation with clear clinical potential. Such approaches typically entail the concurrent injection of contrast agent microbubbles (MBs) and nanoparticles, followed by the application of US to the region of interest. US-activated MBs disrupt the surrounding microvessel, permitting nanoparticle delivery with precise spatial localization. Our group has previously shown that US-targeted nanoparticle delivery can amplify collateral artery growth, that the binding of nanoparticles to MBs enhances nanoparticle delivery, that non-viral gene nanocarrier transfection is dependent on both MB diameter and US pressure, and that solid tumor growth can be controlled by the US-targeted delivery of 5 FU nanoparticles. More recent studies center on developing MRI-guided focused ultrasound (FUS) for nanoparticle delivery across the blood brain-barrier (BBB), which is the foremost impediment to drug treatment for most central nervous system diseases. Importantly, densely PEGylated nanoparticles that have been specifically designed to penetrate brain tissue (i.e., brain-penetrating nanoparticles, BPNs) are capable of crossing the BBB after it is opened with FUS and MBs, thereby supporting the use of gene- and drug-bearing BPNs in combination with MR-guided FUS in treating disorders and pathologies of the CNS.
Ultrasound-mediated delivery of bioactive nanobubbles to vascular tissue
Authors: Sutton Jonathan T. , Raymond Jason L. , Verleye Michael C. , Pyne-Geithman Gail J. , Rubinstein Jack , Holland Christy K.
Published: November 2013

Bubble liposomes (BLs) are under development for ultrasound-triggered release of a potent vasodilator within the vasculature. Nano-sized vesicles facilitate this process by enclosing bubbles to enhance ultrasound image contrast, and deliver therapeutic agents. Assessment of drug delivery in living tissue allows for mechanistic pathways to be revealed. In this study, we used a novel ex vivo model to assess the vascular effects of ultrasound-mediated delivery of a bioactive gas-nitric oxide (NO)-from nanobubble liposomes. Porcine carotid arteries were excised post-mortem and mounted in physiologic buffer. Vascular tone was assessed in real time by coupling the artery to an isometric force transducer. NO-loaded BLs were infused into the lumen of the artery, which was exposed to 1-MHz pulsed ultrasound, while acoustic cavitation emissions were monitored. Changes in vascular tone were concurrently measured and compared to control and sham NO exposures. Our results demonstrate that ultrasound-triggered NO release from BLs induces potent vasorelaxation within porcine carotid arteries. This approach is a valuable mechanistic tool to assess the bioeffects that NO elicits within the vasculature upon release from BLs exposed to 1-MHz ultrasound.
Acoustic droplet vaporization is initiated by superharmonic focusing
Authors: Shpak Oleksandr , Verweij Martin , Vos Rik , de Jong Nico , Lohse Detlef , Versluis Michel
Published: November 2013

Acoustically sensitive emulsion droplets composed of a liquid perfluorocarbon have the potential to be a highly efficient system for local drug delivery, embolotherapy or for tumor imaging. The physical mechanisms underlying the acoustic activation of these phase-change emulsions into a bubbly dispersion, termed acoustic droplet vaporization, have not been well understood. The droplets have a very high activation threshold, its frequency dependence does not comply with homogeneous nucleation theory and focusing spots have been observed. We showed that acoustic droplet vaporization is initiated by a combination of two phenomena: highly nonlinear distortion of the acoustic wave before it hits the droplet, and focusing of the distorted wave by the droplet itself. At high excitation pressures, nonlinear distortion causes significant superharmonics with wavelengths below the diameter of the droplet. Because these superharmonics strongly contribute to the focusing effect, the mechanism also explains pressure thresholding effects. In an accompanying paper, mathematical modeling aspects are presented. A proposed model is validated with experimental data captured with an ultra high-speed camera on the positions of the nucleation spots. Moreover, the presented mechanism explains the hitherto counterintuitive dependence of the nucleation threshold on the ultrasound frequency.
Ultrasonic propagation in suspensions of encapsulated compressible nanoparticles
Authors: Guédra Matthieu , Astafyeva Ksenia , Conoir Jean-Marc , Coulouvrat François , Taulier Nicolas , Thomas Jean-Louis , Urbach Wladimir , Valier-Brasier Tony
Published: November 2013

Dispersion and absorption are examined for dilute suspensions of encapsulated droplets of nanometric size, with typical radii around 100 nm. This new generation of contrast agents is designed for targeted delivery of drugs. Compared to standard contrast agents used for imaging, particles are of smaller size to pass the endothelial barrier, their shell made up of biocompatible material is stiffer to undergo a longer time life and they have a liquid (PFC) instead of a gaseous core. Ultrasound propagation of these suspensions is modeled by combining (i) a dilatational mode of oscillation assuming a compressible shell with a visco-elastic behavior of Kelvin-Voigt or Maxwell type (relaxation), (ii) a translational mode of oscillation induced by visco-inertial interaction with the ambient fluid, and (iii) polydispersion in terms of radius and shell thickness. Influence of the various effects will be examined. Experimental measurements of the dispersion and absorption properties of nanodroplets solutions over the 1–100 MHz frequency range are performed for various temperatures and concentrations. They allow to fit with good accuracy the model properties and estimate some unknown mechanical properties of the shell of the nanodroplets. [Work supported by programme Emergence-UPMC—project NACUNAT and by Inserm/Plan Cancer—project NABUCCO.]
Detection of unique acoustic signatures for phase-change contrast agents used in medical imaging and therapy
Authors: Sheeran Paul S. , Martin Karl H. , Hjelmquist Jordan N. , Matsunaga Terry O. , Dayton Paul A.
Published: November 2013

Phase-change contrast agents (PCCAs) provide a dynamic platform to approach problems in medical ultrasound (US). Upon US-mediated activation, the liquid core vaporizes and expands to produce a gas bubble ideal for US imaging and therapy. In this study, we demonstrate through underlying theory, high-speed microscopy, and US interrogation that PCCAs composed of highly volatile perfluorocarbons (PFCs) exhibit unique acoustic behavior that can be differentiated from tissue and standard microbubble contrast agents. Experimental results show that when activated with short pulses PCCAs will over-expand (6.3× to 7.7× the droplet diameter, PFC dependent) due to momentum of expansion, and undergo unforced, under-damped radial oscillation while settling to a final bubble diameter (5.1× to 5.5× the droplet diameter). Oscillation frequency is inversely related to droplet size—near 100 kHz for droplets ≥ 4 μm in diameter, and 2.5 MHz for droplets near 500 nm. Results from in vitro vessel phantoms using confocal piston transducers with an “activate high” (8 MHz, 2 cycles), “listen low” (1 MHz) scheme show that droplet-specific signals can be detected in both time and frequency domain, and that the magnitude of the acoustic “signature” increases with PFC volatility. These signatures may aid in development of droplet-specific detection techniques.
Bearing measurements using a compact wideband sensor by forming three dipoles
Authors: Brown David A.
Published: November 2013

This paper summaries the development of a compact sensor for determining the bearing angle of an incoming signal using trinary acoustic dipoles. The approach is a kin to the using orthogonal dipoles an omni-reference, which is common in DIFAR sonobuoy. Symmetrically processing three dipoles can offer advantages in sensitivity and extended bandwidth. Analytical and experimental results on the TRI-phase Bearing Estimator, or TRIBE, are presented.
Sound synthesis for a brain stethoscope
Authors: Chafe Chris , Caceres Juan-Pablo , Iorga Michael
Published: November 2013

Exploratory ascultation of brain signals has been prototyped in a project involving neurologists, real-time EEG and techniques for computer-based sound synthesis. In a manner similar to using a stethoscope, the listener can manipulate the location being listened to. Sounds which are heard are sonifications of electrode signals. We present a method for exploring sounds from arrays of sensors as sounds which are useful for distinguishing brain states. The approach maps brain wave signals to modulations characteristic of human voice. Computer-synthesized voices “sing” the dynamics of wakefulness, sleep, seizures, and other states. The goal of the project is to create a recognizable inventory of such vocal “performances” and allow the user to probe source locations in the sensor array in real time.
The Faust Synthesis Toolkit: A set of linear and nonlinear physical models for the Faust programming language
Authors: Michon Romain
Published: November 2013

The Faust Synthesis ToolKit is a set of virtual musical instruments written in the Faust programming language and based on waveguide algorithms and on modal synthesis. Most of them were inspired by instruments implemented in the Synthesis ToolKit (STK) and the program SynthBuilder. Our attention has partly been focused on the pedagogical aspect of the implemented objects. Indeed, we tried to make the Faust code of each object as optimized and as expressive as possible. Some of the instruments in the Faust-STK use nonlinear allpass filters to create interesting and new behaviors. Also, a few of them were modified in order to use gesture data to control the performance. A demonstration of this kind of use is done in the Pure Data program. Finally, the results of some performance tests of the generated C + + code are presented.
Acoustic measurements of the Epsilon rocket at liftoff
Authors: Ishii Tatsuya , Tsutsumi Seiji , Ui Kyoichi , Oinuma Hideshi , Ishii Yutaka , Wada Kei
Published: November 2013

Launch vehicles generate intense acoustic field caused by the enormous thrust power during liftoff, and this acoustic field leads to harmful payload vibration. Japan Aerospace Exploration Agency (JAXA) plans to launch a new solid propellant rocket, Epsilon, in 2013. This three-stage rocket utilizes a reliable first stage motor of the JAXA’s H-2 rocket, SRB-A. Since the SRB-A is expected to cause excessive acoustic load, a countermeasure was required to mitigate the acoustic feedback to the vehicle. Computational works proposed a launch pad structure to attenuate the Mach wave radiation from the plume, and the acoustic wave generated by the plume impinging to the flame deflector. In the previous ASA conference, the authors introduced scale model tests using 1:42 scale rocket motors and the launch pad models. The scale model tests clarified the acoustic benefit of the launch pad structure. The tested geometry of the launch pad structure was adopted to the full-scale structure. Acoustic measurements are planned in the first launch of the Epsilon rocket in order to evaluate the acoustic influence with this newly constructed launch pad structure. The measurement setup and a brief review of the measurements (if possible) are discussed.
Near-field/far-field study of the end-effects regime produced by large area ratio nozzles
Authors: Rojo Raymundo M. , Tinney Charles E. , Baars Woutijn J. , Ruf Joseph H.
Published: November 2013

Vibro-acoustic loads emanating from large area ratio rocket nozzles during start-up can be catastrophic to the launch system and payload. This study quantifies a particular feature referred to as the “end-effects regime”, which is considered the largest source of vibro-acoustic loading during start-up [Nave and Coffey, AIAA Paper 1973-1284]. In this experiment, data acquired during the start-up sequence of several full-scale rocket engines are compared to the laboratory-scale measurements of a thrust-optimized parabolic-contour nozzle conducted in a fully anechoic chamber. The laboratory studies encompass both static and dynamic wall pressures measured inside the nozzle, as well as far-field acoustic surveys. The event produced during the “end-effects regime” was successfully reproduced in the sub-scale model, and was characterized in terms of its mean, variance, and skewness, as well as the spectral properties of the signal obtained by way of time-frequency analyses. The intensity and characteristic frequency of the event of interest are discussed through a comparison of the nominal values for the full-scale and sub-scale system and whether they obey with standard scaling laws.
Effects of pile driving on fishes
Authors: Popper Arthur N. , Halvorsen Michelle B. , Carlson Thomas J. , Smith Michael E. , Casper Brandon M.
Published: November 2013

We examined the physiological effects of impact pile driving on fishes using a specially designed tube that allows replication of the far field acoustic conditions of impulsive stimuli. Studies show that the received signal levels needed to result in onset of effects is a combination of single strike sound exposure level (SELss) and cumulative sound exposure level (SELcum), although not in an equal energy relationship. In contrast to current interim regulations, which indicate that the onset of physiological effects occurs at 187 dB SELcum, our experimental results for six species of fishes showed that the onset of physiological effects, none of which produced mortality, was at about 207 dB SELcum. This onset SELcum had to be at least 7–10 dB higher to result in effects that could potentially be mortal. Additional studies showed that fishes can recover from the effects of pile driving and that a fish species without a swim bladder showed no effects, at least up to an SELcum of 216 dB. Investigations on the effects of pile driving on sensory hair cells of the inner ear, an analog for hearing loss, showed that damage only occurred at SELcum that are substantially higher than onset of other effects.
Evaluation of hydro sound and vibration measurements during the use of the Hydro-Sound-Damper (HSD) at the wind farm “London Array”
Authors: Bruns Benedikt
Published: November 2013

Since some years a noise prevention concept for the protection of marine animals exists in Germany. Based on that, the acoustic underwater noise from the pile driving at offshore wind farms is required to be less than 160 dB (SEL) at a distance of 750 m. This value, however, is often exceeded so that the use of a soundproofing system is necessary. The Hydro-Sound-Damper (HSD) is a new, versatile method to reduce the noise during offshore pile driving. To achieve this, elements of different sizes and materials are used, which are fixed to fishing nets. The principle of operation and the effectiveness of these HSD elements were investigated in the laboratory and in situ under offshore conditions at the world’s largest offshore wind farm “London Array.” During the offshore tests thorough measurements were performed which metered the propagation of the hydro sound and the vibrations of the sea floor at various distances and directions. The evaluation of these data led to very promising results concerning underwater noise reduction. This article describes the theory and implementation of the HSD at “London Array” and focuses on the interpretation of the data from the hydro sound and vibration measurements.
Radiated sound from a scale-model pile submerged in a two-layer medium
Authors: Lee Kevin M. , Hay Todd A. , Weaver Taylor W. , Wilson Preston S. , Hamilton Mark F.
Published: November 2013

Underwater noise due to both marine pile driving and offshore wind farm operation is not only radiated directly from the pile into the water, but also from the seabed surrounding the pile. While there is much interest in mitigating the noise from these activities, a better understanding of the source mechanisms and propagation is needed to determine optimal strategies for noise abatement. A recent analytical model of the acoustic field radiated by submerged piles includes radiation from the pile directly into the water and into a stratified viscoelastic sediment as well as propagation into a shallow water waveguide from both the direct and sediment radiation paths [Hay et al., Proceedings of Meetings on Acoustics 19, 070038 (2013)]. As a step towards validating this model, scale-model experiments were conducted in the high kilohertz frequency range with a model pile consisting of a mechanically excited metallic tube inserted into a laboratory tank filled with two stratified layers to simulate the water/sediment interface. Measurements of the acoustic field in the experiment are compared with the model predictions, and the relevance of these results to implementing noise abatement strategies will be discussed. [Work supported by ARL:UT IR&D.]
The effect of sediment stiffness on the piling pulse—Results from a wave-equation analysis model
Authors: Wood Michael A. , Humphrey Victor F.
Published: November 2013

The rapid expansion of wind farms in UK waters has led to increased concern of the anthropogenic noise emitted into the sea due to piling. The piling process generates high levels of noise capable of propagating over long distances in the water column; it is important that this noise can be predicted, and the likely environmental impact determined. The model presented in this work comprises a method known as Wave Equation Analysis of Piles. This technique models the stress-wave as it propagates along the pile using a finite-difference approach. Additionally, the plastic nature of the sediment is modeled at both the pile wall and pile toe. Previous work has shown that by considering the radial expansion of the pile, the results of this model may be coupled to an acoustic model. The effect of the sediment on the pile motion has previously received little attention. The results show that although the first downward-going pulse is independent of the sediment parameters, reflected pulses are affected. The calculations show that there exists an impedance condition based on the soil parameters: for low soil stiffnesses the pulse is inverted at the toe end, whereas for higher stiffnesses no inversion is seen.
Sound source localization from tactile aids for unilateral cochlear implant users
Authors: Zhong Xuan , Wang Shuai , Dorman Michael , Yost William
Published: November 2013

The present research asks whether two tactile aids with directional microphones, by providing additional inter-channel level information and etc., could help unilateral cochlear implant (CI) localize sound sources. For normal hearing subjects, sound source localization based on tactile vibration cues alone can be as accurate as auditory localization in the frontal horizontal plane (Gescheider, 1970). CI users may as well benefit from additional tactile aids just as normal hearing people do. The current study uses two bone-anchored hearing aids (BAHA) as sources of tactile vibration. The two BAHAs, bonded together by a special gadget to maintain a particular distance and angle, both have directional microphones, and are programed so that one point to the front-left side and the other to the front-right side. Unilateral CI users voluntarily participated in the experimental study. Wide band noise stimuli were presented at 65 dB SPL. The subjects hold one BAHA in each hand and do localization tasks with (1) CI only and (2) with CI and tactile sensation combined. Preliminary data shows CI users can get some benefit from the additional information provided by tactile aids in 360 degree localization (45 degree spacing) on the horizontal plane.
A novel bispectral approach to study cochlear non-linearities in transient evoked otoacoustic emissions
Authors: Tognola Gabriella , Paglialonga Alessia , Chiaramello Emma , Moriconi Stefano
Published: November 2013

A new approach, based on bispectral analysis, is proposed to study non-linearity in cochlear active mechanisms, as evaluated in transient evoked otoacoustic emissions (TEOAEs). Based on an ad hoc formulation of the bispectral analysis, specifically developed in this study to fit the particular features of TEOAEs, this innovative method detects non-linearity by extracting quadratic frequency couplings (QFCs) in TEOAE recordings. The method directly estimates non-linear TEOAE components, which may not be detected by conventional spectral analysis and can thus provide important information useful for better modeling cochlear active mechanisms and to detect sub clinical cochlear dysfunctions. The method was characterized with synthesized TEOAEs as a function of the main TEOAE parameters and then used to analyze TEOAEs recorded in normal hearing adults and full-term neonates to: (i) obtain normative data; (ii) to evaluate test retest repeatability of non-linear interaction mechanisms; and (iii) to investigate the influence of stimulus intensity on non-linear interaction mechanisms. Results revealed that most of the energy of non-linear components is located in the 1–4 kHz range and that the test retest repeatability of non-linear interaction mechanisms is high. The factor that most affects non-linearities is stimulus intensity.
Material identification in frequency-domain coupled acoustic-structure interaction using an error in constitutive equation functional
Authors: Aquino Wilkins , Warner James , Diaz Manuel
Published: November 2013

This work focuses on the inverse identification of linear elastic material parameters in the context of frequency-domain, coupled acoustic-structure interaction. The approach postulates the inverse problem as an optimization problem where the solution is obtained by minimizing a modified error in constitutive equation (MECE) functional. The MECE functional measures the discrepancy in the constitutive equations that connect kinematically admissible strains and dynamically admissible stresses while incorporating the measurement data as an additional quadratic penalty term. The method is formulated generally for the recovery of material properties in a coupled acoustic-structure system using solid displacement and/or fluid pressure measurement data. Numerical results demonstrate that the proposed methodology can identify the spatial distribution of elastic moduli from partial and noisy measurements taken in either the fluid or solid subdomains.
Minimization of the sound radiated by a curved underwater panel
Authors: Shepherd Micah R. , Hambric Stephen A.
Published: November 2013

The sound radiated by a curved underwater panel excited by a point drive is minimized using an evolutionary strategy. The panel thickness is varied in incremental strips along the length of the panel to obtain the optimal configuration. The panel weight and sound radiation are minimized simultaneously using a single weighted objective function. The weighting coefficient is then varied to obtain a Pareto front describing the competing nature of the two objectives. The optimal designs are compared for each weighting coefficient illustrating the tradeoff between minimizing weight and radiated sound power. Normal modes and radiation efficiency curved are also compared. When the optimizer favors minimizing weight, the element thickness is uniformly minimized. Conversely, when the optimizer favors minimizing sound power, the optimal design accepts energy less easily and becomes an inefficient radiator.
Vibroacoustic modeling of ventilation window system with internal partial partitions
Authors: Yu Xiang , Cheng Li
Published: November 2013

Domestic buildings exposed to traffic and environmental noise has always been a major concern. Among various noise control measures, ventilation windows offer appealing features by simultaneously allowing good sound attenuation and air ventilation. However, the modeling of such systems is challenging in that the simulation tools should cope with the complexity of the system; to reach reasonably high frequency range; and to offer the flexibility needed for system optimization. In the present study, the sound transmission through a double-glazed ventilation window is investigated using the patch transfer function method along with a handy treatment of the air aperture and micro-perforated elements. Numerical results show the sound insulation performance can be improved with internal partial partitions, which can be either solid or micro-perforated.
Tuned elastic shells with matched acoustic impedance and sound speed in water
Authors: Titovich Alexey , Amirkulova Feruza
Published: November 2013

Tuning of an elastic shell to match the acoustic properties of the surrounding fluid (water) is done with an internal mechanism consisting of a concentered central mass supported by an axisymmetric distribution of elastic stiffeners. The effective impedance and index are both matched at low frequencies (ka < 1) by adjusting the mass and stiffness of the internal oscillator for a given shell thickness. The subsonic flexural modes of the shell, which are excited by the point attachments of the stiffeners, are ultimately suppressed in the low frequency range with a sufficiently large number of stiffeners. As a result, the scattering cross-section of the tuned shell-stiffener-mass system is negligible compared to the empty shell at frequencies below the resonance of the internal oscillator. An optimal shell thickness exists which maximizes the frequency range of water-like behavior. Furthermore, tuning the effective properties of each such shell in an array is used to achieve acoustic transparency and lensing. Inclusion of damping decreases the magnitude of the internal oscillator resonance without significantly affecting the scattered field. Several planar simulations are presented demonstrating the applications.
Modal analysis of a vibrating string via electromagnetic field excitation
Authors: Filyayev Anton A.
Published: November 2013

An electromagnetic field (EM) generating device (“EBow”) was used to excite a fixed string held in tension between two boundaries on a custom-built apparatus in the style of a monochord. A high-speed camera was used to visualize and record the vibration of the string across the length of the string for every EBow position. The data sets were analyzed to create amplitude vs time graphs. Every excitation position was found to result into a different mode of vibration that emphasized fundamental, second, third, and fourth eigenmodes. Each mode resulted in a distinct displacement pattern, which was found to follow curve fits with R<+>2<+> values ranging from 0.94 to 0.99. The recorded amplitudes also agreed with expected nodal and anti-nodal positions for every observed mode signifying the data were robust. A discrete Fourier series expansion was performed on the polynomial fits and yielded simple second-order expressions (including a damping term) which are in agreement with the expected excitation models for a fixed string.
Glottal articulations in tense vs lax phonation contrasts
Authors: Kuang Jianjing , Keating Patricia
Published: November 2013

This study explores the glottal articulations of one type of phonation contrast—the tense vs lax phonation contrasts of three Yi (Loloish) languages—which is interesting because neither phonation type is very different from modal voice, and both are independent of the languages’ tonal contrasts. Electroglottographic (EGG) recordings were made in the field, and traditional EGG measures showed many small but significant differences between the phonations. Tense phonation involves more overall contact and briefer but slower changes in contact. Functional Data Analysis was then applied to entire EGG pulse shapes, and the resulting first principal component was found to be mostly strongly related to the phonation contrasts, and correlated with almost all the traditional EGG measures. Unlike the traditional measures, however, this component also captures differences in abruptness of contact. Furthermore, previously-collected perceptual responses from native speakers of one of the languages correlated better with this component than with any other EGG measure or any acoustic measure. The articulatory differences between these tense and lax phonations, involving glottal aperture and how glottal closure is made, are not extreme, but apparently they are consistent enough, and perceptually robust enough, to support this linguistic contrast. [Work supported by NSF.]
Language material for English audiovisual speech recognition system development
Authors: Czyzewski Andrzej , Ciszewski Tomasz , Majewicz Dorota , Kostek Bozena
Published: November 2013

The bi-modal speech recognition system requires a 2-sample language input for training and for testing algorithms which precisely depicts natural English speech. For the purposes of the audio-visual recordings, a training data base of 264 sentences (1730 words without repetitions; 5685 sounds) has been created. The language sample reflects vowel and consonant frequencies in natural speech. The recording material reflects both the lexical word frequencies and casual speech sound frequencies in the BNC corpus of approx. 100m words. The semantically and syntactically congruent sentences mirror the 100m-word corpus frequencies. The absolute deviation from source sound frequencies is.09% and individual vowel deviation is reduced to a level between 0.0006% (min.) and 0.009% (max.). The absolute consonant deviation is 0.006% and oscillates between 0.00002% (min.) and 0.012% (max.). Similar convergence is achieved in the language sample for testing algorithms (29 sentences; 599 sounds). The post-recording analysis involves the examination of particular articulatory settings which aid visual recognition as well as co-articulatory processes which may affect the acoustic characteristics of individual sounds. Results of bi-modal speech elements recognition employing the language material are included in the paper.
Characteristics of automatic and human speech recognition processes
Authors: VanDam Mark , Silbert Noah H.
Published: November 2013

In a previous report [VanDam and Silbert (2013) POMA 19, 060006], we investigated performance of a commercially available automatic speech recognition (ASR) system [LENA Research Foundation, Boulder, CO] on acoustic recordings from family speech in naturalistic environments. We found that the ASR more accurately labeled children over adults and fathers over mothers, and human judge labels included substantial individual variation. The present work extends previous work by investigating the possible sources for both machine- and human labeling decisions. Classification tree models were fit to several acoustic variables for machine- and human labels of CHILD, MOTHER, and FATHER. Results suggest that (a) fundamental frequency (f 0) and duration measures influenced label assignment for both machine and human classifications, (b) the error of the fitted models is lower for the machine labeling procedure than for human judges, (c) machine- and human decision processes use the acoustic criteria (i.e., f 0 and duration) differently, and (d) f 0 is more important than duration for all labelers. Results may have implications for improving implementation and interpretation of ASR techniques, especially as they are useful for understanding child language applications and very large, naturalistic datasets that demand unsupervised ASR techniques.
Perception of Scottish Gaelic alternating (leniting) consonants
Authors: Warner Natasha L. , Clayton Ian , Carnie Andrew , Fisher Muriel , Brenner Dan , Hammond Michael , Archangeli Diana , Ussishkin Adam
Published: November 2013

Scottish Gaelic, an endangered Celtic language, demonstrates alternations in word-initial consonants, as in “pòg” [phok] 'kisses' vs “phòg” [fok] 'kissed.' This process, called lenition, leads to apparent neutralizations of Gaelic segments, for example of the [f] of “ phòg” with [f] of “foghlam” [foɫəm] “education,” which is not caused by lenition. A perception experiment can show whether listeners hear any residual difference between lenited segments (e.g., [f]<-[ph]) and the phonetically similar segments ([f]<-[f]). This project used a gating study to investigate when in the word listeners determine which type of sound they are hearing. Preliminary results from 17 native Gaelic listeners indicate that listeners cannot distinguish lenited from phonetically matched consonants (e.g., the two types of [f]) from cues in the consonant itself, but can distinguish both from the unlenited phonologically matched consonants (e.g., [ph]) very accurately. Listeners become able to distinguish lenited from phonetically matched segments (the two types of [f]) during either the following vowel or the segment after that, depending on what coarticulatory cues with the latter parts of the word are available. Thus, listeners need enough acoustic information to provide lexical disambiguation in order to determine the morphological source of lenited sounds.
Discrimination between fricatives and affricates pronounced by Japanese native speakers at various speaking rates
Authors: Yamakawa Kimiko , Amano Shigeaki
Published: November 2013

Fricatives [s] and affricates [ts] uttered at a normal speaking rate are successfully discriminated with two variables: a rise part duration and a steady + decay part duration [Yamakawa et al., Acoust. Sci. Tech. 33(3), 154–159 (2012)]. This study examined whether [s] and [ts] uttered at various speaking rates are also well discriminated with these variables. Discriminant analyses with the two variables were performed on [s] and [ts] in word-initial position in a carrier sentence pronounced by eight native Japanese speakers at fast, normal, and slow speaking rates. Discriminant error rates were low for the fast (9.8%, n = 512), normal (5.7%, n = 512), and slow (13.1%, n =512) speaking rates. However, the error rate was high (22.0%, n = 1536) when the three speaking rates were analyzed together. It decreased to 15.7% when the two variables were normalized with an averaged mora duration of the carrier sentence. These results suggest that [s] and [ts] can be discriminated at various speaking rates with a normalized rise part duration and normalized steady + decay part duration. [This work was supported by JSPS KAKENHI Grant Numbers 22720173, 24652087, and 25284080, and by Aichi Shukutoku University Special Research Grant 2011-2012 and Corporate Research Grant 2013-2014.]
Relationship of training of pitch-pattern reconstruction ability to speech perception in normal-hearing young adults
Authors: Cortese Kristen M. , Sheft Stanley , Shafiro Valeriy , Stiles Derek J.
Published: November 2013

Previous research has indicated that processing of pitch changes is related to speech perception. Current work investigated the relationship of pitch-pattern training to speech perception in young normal-hearing adults. The training protocol was based on an interactive pattern-reconstruction task in which listeners assembled four or five tones (frequency: 400–1750 Hz, duration: 75–600 ms) to match a random target sequence. Control and experimental groups, of 13 subjects each, were tested. The study included a pretest, three training sessions (experimental group only), and a posttest. Training consisted of three 40-min sessions of interactive pitch-pattern reconstruction. In the pre- and posttest, listeners also reconstructed patterns of sinewave speech, and completed measures of speech perception which included sinewave speech and speech-in-noise tasks. Despite training with only tonal patterns, results showed significant improvement in the ability to reconstruct patterns for both tonal and sinewave-speech stimuli. Significant improvements were obtained for intelligibility of sinewave speech between pre- and posttest, which were greater for the experimental than control group. A greater relationship between results from the intelligibility and pattern-reconstruction conditions post training was also found. Overall, results suggest that the training protocol may benefit speech perception, especially in conditions of degraded speech. [Work supported by NIDCD.]