bluuebunny/crossref_metadata_2025 huggingface dataset:
Applications of telematic mixing consoles in networked audio for musical performance, spatial audio research, and sound installations
Authors: Samson David J. , Braasch Jonas
Published: October 2014

In today’s technologically driven world, the ability to connect across great distance via Internet Protocol is more important than ever. As the technology evolves, so does the art and science that relies upon it for collaboration and growth. Developing the state of the art system for flexible and efficient routing of networked audio provides a platform for experimental musicians, researchers, and artists to create freely without the restrictions imposed by traditional telepresence. Building on previous development and testing of a telematic mixing console while addressing critical issues with the current platform and current practice, the console allows for the integration of high-quality networked audio into computer assisted virtual environments (CAVE systems), sound and art installations, and other audio driven research projects. Through user study, beta testing, and integration into virtual audio environments, the console has evolved to meet the demand for power and flexibility critical to multi-site collaboration with high-quality networked audio. Areas of concern addressed in development are computational efficiency, system latency, routing architecture, and results of continued user study.
Comparing the acoustical nature of a compressed earth block residence to a traditional wood-framed residence
Authors: Butko Daniel
Published: October 2014

Various lost, misunderstood, or abandoned materials and methods throughout history can serve as viable options in today’s impasse of nature and mankind. Similar to the 19th century resurgence of concrete, there is a developing interest in earth as an architectural material capable of dealing with unexpected fluctuations and rising climate changes. Studying the acoustical nature of earthen construction can also serve as a method of application beyond aesthetics and thermal comfort. Innovations using Compressed Earth Block (CEB) have been developed and researched over the past few decades and recently the collaborative focus for a collaborative team of faculty and students at a NAAB accredited College of Architecture, an ABET accredited College of Engineering, and a local chapter of Habitat for Humanity. The multidisciplinary research project resulted in the design and simultaneous construction of both a CEB residence and a conventionally wood-framed version of equal layout, area, volume, apertures, and roof structure on adjacent sites to prove the structural, thermal, economical, and acoustical value of CEB as a viable residential building material. This paper defines acoustical measurements of both residences such as STC, OITC, TL, NC, FFT, frequency responses, and background noise levels prior to occupancy.
A case study of a high end residential condominium building acoustical design and field performance testing
Authors: Ryerson Erik J. , Rafferty Tom
Published: October 2014

A high end multi-owner condominium building complex consists of 314 units configured in a central tower with a 39-story central core, as well as 21 and 30 story side towers. A series of project specific acoustical design considerations related to condominium unit horizontal and vertical acoustical separation as well as background noise control for building HVAC systems were developed for the project construction documents and later field tested to confirm conformance with the acoustical design criteria. This paper presents the results of these building wide field tests as well as a discussion of pitfalls encountered during design, construction, and post-construction.
Innovative ways to make cross laminated timber panels sound-absorptive
Authors: Logawa Banda , Hodgson Murray
Published: October 2014

Cross Laminated Timber (CLT) panels typically consist of several glued layers of wooden boards with orthogonally alternating directions. This cross-laminating process allows CLT panels to be used as load-bearing plate elements similar to concrete slabs. However, they are very sound-reflective, which can lead to concerns about acoustics. Growing interest in applications of CLT panels as building materials in North America has initiated much current research on their acoustical properties. This project is aimed at investigating ways to improve the sound-absorption characteristics of the panels by integrating arrays of Helmholtz-resonator (HR) absorbers into the panels and establishing design guidelines for CLT-HR absorber panels for various room-acoustical applications. To design the new prototype panels, several efforts have been made to measure and analyze the sound-absorption characteristics of the exposed CLT surfaces in multiple buildings in British Columbia, investigate suitable methods and locations to measure both normal and random incidence sound absorption characteristics, study the current manufacturing method of CLT panels, create acoustic models of CLT-HR absorber panels with various shapes and dimensions, and evaluate the sound absorption performance of prototype panels. This paper will report progress on this work.
Changes in note order stereotypy during learning in two species of songbird, measured with automatic note classification
Authors: Taft Benjamin N.
Published: October 2014

In addition to mastering the task of performing the individual notes of a song, many songbirds must also learn to produce each note in a stereotyped order. As a bird practices its new song, it may perform thousands of bouts, providing a rich source of information about how note phonology and note type order change during learning. A combination of acoustic landmark descriptions, neural network and hierarchical clustering classifiers, and Markov models of note order made it possible to measure note order stereotypy in two species of songbird. Captive swamp sparrows (Melospiza melodia, 11 birds, 92063 notes/bird), and wild tree swallows (Tachycineta bicolor, 18 birds, 448 syllables/bird) were recorded song development. The predictability of swamp sparrow note order showed significant increase during the month-long recording period (F1,162 = 9977, p < 0.001). Note order stereotypy in tree swallows also increased by a significant amount over a month-long field season (Mann-Whitney V = 12, p-value < 0.001). Understanding changes in song stereotypy can improve our knowledge of vocal learning, performance, and cultural transmission.
Importing acoustic metadata into the Tethys scientific workbench/database
Authors: Herbert Sean T. , Roch Marie A.
Published: October 2014

Tethys is a temporal-spatial scientific workbench/database created to enable the aggregation and analysis of acoustic metadata from recordings such as animal detections and localizations. Tethys stores data in a specific format and structure, but researchers produce and store data in various formats. Examples of storage formats include spreadsheets, relational databases, or comma-separated value (CSV) text files. Thus, one aspect of the Tethys project has been to focus on providing options to allow data import regardless of the format in which it is stored. Data import can be accomplished in one of two ways. The first is translation, which transforms source data from other formats into the format Tethys uses. Translation does not require any programming, but rather the specification of an import map which associates the researcher’s data with Tethys fields. The second method is a framework called Nilus that enables detection and localization algorithms to create Tethys formatted documents directly. Programs can either be designed around Nilus, or be modified to make use of it, which does require some programming. These two methods have been used to successfully import over 4.5 million records into Tethys. [Work funded by NOPP/ONR/BOEM.]
First measurements of humpback whale song received sound levels recorded from a tagged calf
Authors: Chen Jessica , Au Whitlow W. L. , Pack Adam A.
Published: October 2014

There is increasing concern over the potential ecological effects from high levels of oceanographic anthropogenic noise on marine mammals. Current US NOAA regulations on received noise levels as well as the Draft Guidance for Assessing the Effect of Anthropogenic Sound on Marine Mammals are based on limited studies conducted on few species. For the regulations to be effective, it is important to first understand what whales hear and their received levels of natural sounds. This novel study presents the measurement of sound pressure levels of humpback whale song received at a humpback whale calf in the wintering area of Maui, Hawaii. This individual was tagged with an Acousonde acoustic and data recording tag and captured vocalizations from a singing male escort associated with the calf and its mother. Although differences in behavioral reaction to anthropogenic versus natural sounds have yet to be quantified, this represents the first known measurement of sound levels that a calf may be exposed to naturally from conspecifics. These levels can also be compared to calculated humpback song source levels. Despite its recovering population, the humpback whale is an endangered species and understanding their acoustic environment is important for continued regulation and protection.
Investigating whistle characteristics of three overlapping populations of false killer whales (Pseudorca crassidens) in the Hawaiian Islands
Authors: Barkley Yvonne M. , Oleson Erin , Oswald Julie N.
Published: October 2014

Three genetically distinct populations of false killer whales Pseudorca crassidens) reside in the Hawaiian Archipelago: two insular populations (one within the main Hawaiian Islands [MHI] and the other within the Northwestern Hawaiian Islands [NWHI]), and a wide-ranging pelagic population with a distribution overlapping the two insular populations. The mechanisms that created and maintain the separation among these populations are unknown. To investigate the distinctiveness of whistles produced by each population, we adapted the Real-time Odontocete Call Classification Algorithm (ROCCA) whistle classifier to classify false killer whale whistles to population based on 54 whistle measurements. 911 total whistles from the three populations were included in the analysis. Results show that the MHI population is vocally distinct, with up to 80% of individual whistles correctly classified. The NWHI and pelagic populations achieved between 48 and 52% correct classification for individual whistles. We evaluated the sensitivity of the classifier to the input whistle measurements to determine which variables are driving the classification results. Understanding how these three populations differ acoustically may improve the efficacy of the classifier and create new acoustic monitoring approaches for a difficult-to-study species.
Sound intensity fluctuations due to mode coupling in the presence of nonlinear internal waves in shallow water
Authors: Katsnelson Boris , Grogirev Valery , Lynch James
Published: October 2014

Intensity fluctuations of the low frequency LFM signals (band 270–330 Hz) were observed in Shallow Water 2006 experiment in the presence of moving train consisting of about seven separate nonlinear internal waves crossing acoustic track at some angle (~ 80º). It is shown that spectrum of the sound intensity fluctuations calculated for time period of radiation (about 7.5 minutes) contains a few peaks, corresponding to predominating frequency ~6.5 cph (and its harmonics) and small peak, corresponding to comparatively high frequency, about 30 cph, which is interpreted by authors as manifestation of horizontal refraction. Values of mentioned frequencies are in accordance with theory of mode coupling and horizontal refraction on moving nonlinear internal waves, developed earlier by authors. [Work was supported by BSF.]
A computerized tomography system for transcranial ultrasound imaging
Authors: Tang Sai Chun , Clement Gregory T.
Published: October 2014

Hardware for tomographic imaging presents both challenge and opportunity for simplification when compared with traditional pulse-echo imaging systems. Specifically, point diffraction tomography does not require simultaneous powering of elements, in theory allowing just a single transmit channel and a single receive channel to be coupled with a switching or multiplexing network. In our ongoing work on transcranial imaging, we have developed a 512-channel system designed to transmit and/or receive a high voltage signal from/to arbitrary elements of an imaging array. The overall design follows a hierarchy of modules including a software interface, microcontroller, pulse generator, pulse amplifier, high-voltage power converter, switching mother board, switching daughter board, receiver amplifier, analog-to-digital converter, peak detector, memory, and USB communication. Two pulse amplifiers are included, each capable producing up to 400 Vpp via power MOSFETS. Switching is based around mechanical relays that allow passage of 200 V, while still achieving switching times of under 2 ms, with an operating frequency ranging from below 100 kHz to 10 MHz. The system is demonstrated through ex vivo human skulls using 1 MHz transducers. The overall system design is applicable to planned human studies in transcranial image acquisition, and may have additional tomographic applications for other materials necessitating a high signal output. [Work was supported by NIH R01 EB014296.]
Neuronal synchronization of musical large-scale form
Authors: Hartmann Lenz
Published: October 2014

Musical form in this study is taken as structural aspects of music ranging over several bars as a combination of all elements that constitutes a piece of music, like pitch, rhythm or timbre. In an EEG-study 25 participants listen to the first about four minutes of a piece of electronic dance music for three times each and ERP grand-averages were calculated. Correlations of a one second time windows between the ERPs of all electrodes and therefore of different brain regions is used as a measure of synchronization between these areas. Local maxima corresponding to strong synchronization show up at expectancy points of boundaries in the present musical form. A modified FFT analysis of the ERPs of the mean of all trials and all channels that just take the ten highest peaks in consideration show strongest brain activity at frequencies in the gamma-band (about 40–60 Hz) and in the beta-band (about 20–30 Hz).
Comparison of impulse peak insertion loss measured with gunshot and shock tube noise sources
Authors: Murphy William J. , Berger Elliott H. , Ahroon William A.
Published: October 2014

The National Institute for Occupational Safety and Health in cooperation with scientists from 3M and the U.S. Army Aeromedical Research Laboratory conducted a series of Impulse peak insertion loss (IPIL) tests of the acoustic test fixtures from the Institute de Saint Louis (ISL) with a 0.223 caliber rifle and two different acoustic shock tubes. The Etymotic Research ETYPlugs™ earplug, 3M™ TacticalPro™ communication headset and the dual protector combination were tested with all three impulse noise sources. The spectra, IPIL, and the reduction of different damage risk criteria will be presented. The spectra from the noise sources vary considerably with the rifle having peak energy at about 1000 Hz. The shock tubes had peak levels around 125 and 250 Hz. The IPIL values for the rifle were greater than those measured with the two shock tubes. The shock tubes had comparable IPIL results except at 150 dB for the dual protector condition. The treatment of the double protection condition is complicated because the earmuff reduces the shock wave and reduces the effective level experienced by the earplug. For the double protection conditions, bone conduction presents a potential limiting factor for the effective attenuation that can be achieved by hearing protection.
Large-eddy simulations of impinging over-expanded supersonic jet noise for launcher applications
Authors: Troyes Julien , Vuillot François , Lambaré Hadrien
Published: October 2014

During the lift-off phase of a space launcher, powerful rocket motors generate harsh acoustic environment on the launch pad. Following the blast waves created at ignition, jet noise is a major contributor to the acoustic loads received by the launcher and its payload. Recent simulations performed at ONERA to compute the noise emitted by solid rocket motors at lift-off conditions are described. Far-field noise prediction is achieved by associating a LES solution of the jet flow with an acoustics surface integral method. The computations are carried out with in-house codes CEDRE for the LES solution and KIM for Ffowcs Williams & Hawkings porous surface integration method. The test case is that of a gas generator, fired vertically onto a 45 degrees inclined flat plate which impingement point is located 10 diameters from nozzle exit. Computations are run for varied numerical conditions, such as turbulence modeling along the plate and different porous surfaces location and type. Results are discussed and compared with experimental acoustic measurements obtained by CNES at MARTEL facility.
Influence of the workmanship on the airborne sound insulation properties of light weight building plasterboard steel frame wall systems
Authors: Muellner Herbert , Jakits Thomas
Published: October 2014

Building elements which are built according to the light weight mode of construction, e.g. plasterboard steel frame wall systems show a large variation of air borne sound insulation properties although the elements appear as identical. According to several studies conducted in the recent years, certain aspects of workmanship have significant influence on the air borne sound insulation characteristics of light weight building elements. The method to fasten the planking (e.g., gypsum boards, gypsum fiber boards) as well as the number and position of the screws can lead to considerable variations regarding the sound insulation properties. Above 200 Hz, the sound reduction index R can differ more than 10 dB by the variation of the position of the screws. Applying prefabricated composite panels of adhesive connected plasterboards not only considerably reduces the depth of the dip of the critical frequency caused by the higher damping due to the interlayer but it can also significantly decrease the negative influence of the workmanship on the air borne sound insulation properties of these kinds of light weight walls in comparison to the standard planking of double layer plasterboard systems. The influence of secondary construction details and workmanship will be discussed in the paper.
Contribution of floor treatment characteristics to background noise levels in health care facilities, Part 1
Authors: Paul Adam L. , Arena David A. , King Eoin A. , Celmer Robert , LoVerde John J.
Published: October 2014

Acoustical tests were conducted on five types of commercial-grade flooring to assess their potential contribution to noise generated within health care facilities outside of patient rooms. The floor types include sheet vinyl (with and without a 5 mm rubber backing), virgin rubber (with and without a 5 mm rubber backing), and a rubber-backed commercial grade carpet for comparison. The types of acoustical tests conducted were ISO-3741 compliant sound power level testing (using two source types: a tapping machine to simulate footfalls and a rolling hospital cart), and sound absorption testing as per ASTM-C423. Among the non-carpet samples, the material type that produced the least sound power was determined to be the rubber-backed sheet vinyl. While both 5 mm-backed samples showed a significant difference compared to their un-backed counterparts with both source types, the rubber-backed sheet vinyl performed slightly better than the rubber-backed virgin rubber in the higher frequency bands in both tests. The performance and suitability of these flooring materials in a health care facility compared to commercial carpeting will be discussed. [Work supported by Paul S. Veneklasen Research Foundation.]
LabTau's experience in therapeutic ultrasound : From lithotripsy to high intensity focused ultrasound
Authors: Chapelon Jean-Yves , Canney Michael , Melodelima David , Lafon Cyril
Published: October 2014

Research on therapeutic ultrasound at LabTau (INSERM Lyon, France) began in the early 1980s with work on shock waves that lead to the development of the first ultrasound-guided lithotripter. In 1989, this research shifted towards new developments in the field of HIFU with applications in urology and oncology. The most significant developments have been obtained in urology with the Ablatherm™ project, a transrectal HIFU device for the thermal ablation of the prostate. This technology has since become an effective therapeutic alternative for patients with localized prostate cancer. Since 2000, three generations of the Ablatherm™ have been CE marked and commercialized by EDAP-TMS. The latest version, the FocalOne™, allows for the focal treatment of prostate cancer and combines dynamic focusing and fusion of MR images to ultrasound images acquired in real time by the imaging probe integrated in the HIFU transducer. Using toroidal ultrasound transducers, a HIFU device was also recently validated clinically for the treatment of liver metastases. Another novel application that has reached the clinic is for the treatment of glaucoma using a miniature, disposable HIFU device. Today, new approaches are also being investigated for treating cerebral and cardiac diseases.
Artificial viscosity in smoothed particle hydrodynamics simulation of sound interference
Authors: Li Xu , Zhang Tao , Zhang YongOu , Ouyang Huajiang , Liu GuoQing
Published: October 2014

The artificial viscosity has been widely used in reducing unphysical oscillations in the Smoothed Particle Hydrodynamics (SPH) simulations. However, the effects of artificial viscosity on the SPH simulation of sound interference have not been discussed in existing literatures. This paper analyzes the effects and gives some suggestions on the choice of computational parameters of the artificial viscosity in the sound interference simulation. First, a standard SPH code for simulating sound interference in the time domain is built by solving the linearized acoustic wave equations. Second, the Monaghan type artificial viscosity is used to optimize the SPH simulation. Then the SPH codes with and without the artificial viscosity are both used to simulate the sound interference and the numerical solutions are compared with the theoretical results. Finally, different values of computational parameters of the artificial viscosity are used in the simulation in order to determine the appropriate values. It turns out that the numerical solutions of SPH simulation of sound interference agree well with the theoretical results. The artificial viscosity can improve the accuracy of the sound interference simulation. The appropriate values of computational parameters of the artificial viscosity are recommended in this paper.
A high-order Cartesian-grid finite-volume method for aeroacoustics simulations
Authors: H. Farahani Mehrdad , Mousel John , Vigmostad Sarah
Published: October 2014

A moving-least-square based finite-volume method is developed to simulate acoustic wave propagation and scattering from complicated solid geometries. This hybrid method solves the linearized perturbed compressible equations as the governing equations of the acoustic field. The solid boundaries are embedded in a uniform Cartesian grid and represented using level set fields. Thus, the current approach avoids unstructured grid generation for the irregular geometries. The desired boundary conditions are imposed sharply on the immersed boundaries using a ghost fluid method. The scope of the implementation of the moving moving-least-square approach in the current solver is threefold: reconstruction of the field variables on cell faces for high-order flux construction, population of the ghost cells based on the desired boundary condition, and filtering the high wave number modes near the immersed boundaries. The computational stencils away from the boundaries are identical; hence, only one moving-least-square shape-function is computed and stored with its underlying grid pattern for all the interior cells. This feature significantly reduces the memory requirement of the acoustic solver compared to similar finite-volume method on irregular unstructured mesh. The acoustic solver is validated against several benchmark problems.
Transmission loss and reverberation variability during TREX13
Authors: Pecknold Sean , McCammon Diana , Tang Dajun
Published: October 2014

The ONR-funded Target and Reverberation Experiment 2013 (TREX13) took place in the Northeastern Gulf of Mexico near Panama City, Florida, during April and May of 2013. During this trial, which took place in a shallow water (20 m deep) environment, several sets of one-way and two-way acoustic transmission loss and reverberation data were acquired. Closed form expressions are derived to trace the uncertainty in the inputs to a Gaussian beam propagation model through the model to obtain an estimate of the uncertainty in the output, both for transmission loss and for reverberation. The measured variability of the TREX environment is used to compute an estimate of the expected transmission loss and reverberation variability. These estimates are then compared to the measured acoustic data from the trial.
Effect of a roughened sea surface on shallow water propagation with emphasis on reactive intensity obtained with a vector sensor
Authors: Dall'Osto David R. , Dahl Peter H.
Published: October 2014

In this study, sea-surface conditions during the Targets and Reverberation Experiment (TREX) are analyzed. The sea-surface directional spectrum was experimentally measured up to 0.6 Hz with two wave buoys separated by 5 km. The analysis presented here focuses on propagation relating to three canonical sea-surfaces observed during the experiment: calm conditions, and rough conditions with waves either perpendicular or parallel to the primary propagation direction. Acoustic data collected during calm and rough conditions show a significant difference in the amount of out-of-plane scattering. Interference due to this out-of-plane scattering is observed in the component of reactive intensity perpendicular to the propagation direction. These observations are compared with those generated using a model of the sea-surface scattering based on a combination of buoy-measured and modeled directional spectrum. Simulated sea-surfaces are also constructed for this numerical study. A model for wind waves is used to obtain surface wavenumbers greater than those measured by the wave buoys (~1.5 rad/m). Importantly, the spectral peak and it direction are well measured by the buoys and no assumptions on fetch are required, resulting in a more realistic wave spectrum and description of sea-surface conditions for acoustic modeling.
Reducing cognitive demands on listeners by speaking clearly in noisy places
Authors: Van Engen Kristin
Published: October 2014

Listeners have more difficulty identifying spoken words in noisy environments when those words have many phonological neighbors (i.e., similar-sounding words in the lexicon) than when they have few phonological neighbors. This difficulty appears to be exacerbated in old age, where reductions in inhibitory control presumably make it more difficult to cope with competition from similar-sounding words. Fortunately, word recognition in noise can generally be improved for a wide range of listeners (e.g., younger and older adults, individuals with and without hearing impairment) when speakers adopt a clear speaking style. This study investigated whether clear speech, in addition to generally increasing speech intelligibility, also reduces the inhibitory demands associated with identifying lexically difficult words in noise for younger and older adults. The results show that, indeed, the difference between rates of identification for words with many versus few neighbors was eliminated when those words were produced in clear speech. Data on the roles of individual differences (e.g., hearing, working memory, and inhibitory control) that may contribute to word identification in noise will also be presented.
Use of passive acoustics for estimation of cetacean population density: Realizing the potential
Authors: Barlow Jay , Rankin Shannon
Published: October 2014

The potential of passive acoustic methods to estimate cetacean population density has seldom been realized. It has been most successfully applied to species that consistently use echo-location during foraging, have very distinctive echo-location signals and forage a large fraction of the time, notably sperm whale, porpoise, and beaked whales. Research is needed to eliminate some of the impediments to applying acoustics to estimate the density of other species. For baleen whales, one of the greatest uncertainties is the lack of information on call rates. For delphinids, the greatest uncertainties are in estimating group size and in species recognition. For all species, there is a need to develop inexpensive recorders that can be distributed in large number at random locations in a study area. For towed hydrophone surveys, there is a need to better localize species in their 3-D environment and to instantaneously localize animals from a single signal received on multiple hydrophones. While improvements can be made, we may need to recognize that some of impediments cannot be overcome with any reasonable research budget. In these cases, efforts should be concentrated in improving acoustic methods to aid visual-based transect methods.
Towing the line: Line-transect based density estimation of whales using towed hydrophone arrays
Authors: Norris Thomas F. , Yack Tina M.
Published: October 2014

Towed hydrophone arrays have been used to monitor marine mammals from research vessels since the 1980s. Although towed hydrophone arrays have now become a standard part of line-transect surveys of cetaceans, density estimation exclusively using passive acoustic has only been attempted for a few species. We use examples from four acoustic line-transect surveys that we conducted in the North Pacific Ocean to illustrate the steps involved, and issues inherent, in using data from towed hydrophone arrays to estimate densities of cetaceans. We will focus on two species of cetaceans, sperm whales and minke whales, with examples of beaked whales and other species as needed. Issues related to survey design, data-collection, and data analysis and interpretation will be discussed using examples from these studies. We provide recommendations to improve the survey design, data-collection methods, and analyses. We also suggest areas where additional research and methodological development are required in order to produce robust density estimates from acoustic based data.
Studying the biosonar activities of deep diving odontocetes in Hawaii and other western Pacific locations
Authors: Au Whitlow W. , Giorli Giacomo
Published: October 2014

Ecological acoustic recorders (EARs) have been deployed at several locations in Hawaii and in other western Pacific locations to study the foraging behavior of deep-diving odontocetes. EARs have been deployed at depths greater than 400 m at five locations around the island of Kauai, one at Ni’ihau, two around the island of Okinawa, and four in the Marianas (two close to island of Guam, one close to the island of Saipan and another close to the island of Tinian). The four groups of deep-diving odontocetes were blackfish (mainly pilot whales and false killer whales), sperm whales, beaked whales (Cuvier and Bainsville beaked whales) and Risso’s dolphin. In all locations, the biosonar signals of blackfish were detected the most followed by either by sperm and beaked whales depending on specific locations with Risso’s dolphin being detected the least. There was a strong tendency for these animals to forage at night in all locations. The detection rate indicate much lower populations of these four groups of odontocetes around Okinawa and in the Marianas then off Kauai in the main Hawaiian island chain by a factor of about 4–5.
Instantaneous acoustical response of marine mammals to abrupt changes in ambient noise
Authors: Joseph John E. , Margolina Tetyana , Huang Ming-Jer
Published: October 2014

Four months of passive acoustic data recorded at Thirtymile Bank in offshore southern California have been analyzed to describe instantaneous vocal response of marine mammals to abrupt changes in ambient noise. Main contributors to the distinctive regional soundscape are heavy commercial shipping, military activities in the naval training range, diverse marine life and natural sources including wind and tectonic activity. Many of these sources produce intense, irregular and short-term events shaped by local oceanographic conditions, bathymetry and bottom structure (Thirtymile Bank blind thrust). We seek to attribute detected changes in cetacean vocal behavior (loudness, calling rate, and pattern) to these events and differentiate the reaction by noise source, its intensity, frequency and/or duration. Main target species are blue and fin whales. Initial hypotheses formulated after data scanning are tested statistically (2D histograms and PCA). To quantify the vocal behavior variations, an innovative detection approach based on pattern recognition is applied, which allows for extraction of individual calls with low false alarm and high detection success comparable to those of a human analyst. Obtained results relate cetacean acoustic behavior to ambient noise variability and thus help refine existing cue-based formulae for estimation of whale population density from PAM data.
Measuring whale and dolphin call rates as a function of behavioral, social, and environmental context
Authors: DeRuiter Stacy L. , Harris Catriona M. , Quick Nicola J. , Sadykova Dina , Scott-Hayward Lindesay A. , Stimpert Alison K. , Southall Brandon L. , Thomas Len , Visser Fleur
Published: October 2014

Cetacean sound-production rates are highly variable and patchy in time, depending upon individual behavior, social context, and environmental context. Better quantification of the drivers of this variability should allow more realistic estimates of expected call rates, improving our ability to convert between call counts and animal density, and also facilitating detection of sound-production changes due to acoustic disturbance. Here, we analyze digital acoustic tag (DTAG) records and visual observations collected during behavioral response studies (BRSs), which aim to assess normal cetacean behavior and measure changes in response to acoustic disturbance; data sources include SOCAL BRS, the 3S project, and Bahamas BRS, with statistical contributions from the MOCHA project (http://www.creem.st-and.ac.uk/mocha/links). We illustrate use of generalized linear models (and their extensions) as a flexible framework for sound-production-rate analysis. In the context of acoustic disturbance, we also detail use of two-dimensional spatially adaptive surfaces to jointly model effects of sound-source proximity and sound intensity. Specifically, we quantify variability in pilot whale group sound production rates in relation to behavior and environment, and individual fin whale call rates in relation to social and environmental context and dive behavior; with and without acoustic disturbance.
The role of tissue mechanical properties in histotripsy tissue fractionation
Authors: Vlaisavljevich Eli , Cain Charles , Xu Zhen
Published: October 2014

Histotripsy is a therapeutic ultrasound technique that controls cavitation to fractionate tissue using short, high-pressure ultrasound pulses. Histotripsy has been demonstrated to successfully fractionate many different tissues, though stiffer tissues such as cartilage or tendon (Young’s moduli >1 MPa) are more resistant to histotripsy-induced damage than softer tissues such as liver (Young’s moduli ~9 kPa). In this work, we investigate the effects of tissue mechanical properties on various aspects of the histotripsy process including the pressure threshold required to generate a cavitation cloud, the bubble dynamics, and the stress–strain applied to tissue structures. Ultrasound pulses of 1–2 acoustic cycles at varying frequencies (345 kHz, 500 kHz, 1.5 MHz, and 3 MHz) were applied to agarose tissue phantoms and ex vivo bovine tissues with varying mechanical properties. Results demonstrate that the intrinsic threshold to initiate a cavitation cloud is independent of tissue stiffness and frequency. The bubble expansion is suppressed in stiffer tissues, leading to a decrease in strain to surrounding tissue and an increase in damage resistance. Finally, we investigate strategies to optimize histotripsy therapy for the treatment of tissues with specific mechanical properties. Overall, this work improves our understanding of how tissue properties affect histotripsy and will guide parameter optimization for histotripsy tissue fractionation.
Histotripsy: Urologic applications and translational progress
Authors: Roberts William W. , Cain Charles A. , Fowlkes J. B. , Xu Zhen , Hall Timothy L.
Published: October 2014

Histotripsy is an extracorporeal ablative technology based on initiation and control of acoustic cavitation within a target volume. This mechanical form of tissue homogenization differs from the ablative processes employed by conventional thermoablative modalities and exhibits a number of unique features (non-thermal, high precision, real-time monitoring/feedback, and tissue liquefaction), which are potentially advantageous characteristics for ablative applications in a variety of organs and disease processes. Histotripsy has been applied to the prostate in canine models for tissue debulking as a therapy for benign prostatic hyperplasia and for ablation of ACE-1 tumors, a canine prostate cancer model. Homogenization of normal renal tissue as well as implanted VX-2 renal tumors has been demonstrated with histotripsy. Initial studies assessing tumor metastases in this model did not reveal metastatic potentiation following mechanical homogenization by histotripsy. Enhanced understanding of cavitation and methods for acoustic control of the target volume are being refined in tank studies for treatment of urinary calculi. Development of novel acoustic pulsing strategies, refinement of technology, and enhanced understanding of cavitational bioeffects are driving pre-clinical translation of histotripsy for a number of applications. A human pilot trial is underway to assess the safety of histotripsy as a treatment for benign prostatic hyperplasia.
Boiling histotripsy of the kidney: Preliminary studies and predictors of treatment effectiveness
Authors: Schade George R. , Maxwell Adam D. , Khokhlova Tatiana , Wang Yak-Nam , Sapoznikov Oleg , Bailey Michael R. , Khokhlova Vera
Published: October 2014

Boiling histotripsy (BH), an ultrasound technique to mechanically homogenize tissue, has been described in ex vivo liver and myocardium. As a noninvasive, non-thermal based approach, BH may have advantages over clinically available thermal ablative technologies for renal masses. We aimed to characterize BH exposures in human and porcine ex vivo kidneys using a 7-element 1 MHz transducer (duty factor 1–3%, 5–10 ms pulses, 98 MPa in situ shock amplitude, 17 MPa peak negative). Lesions were successfully created in both species, demonstrating focally homogenized tissue above treatment thresholds (pulse number) with stark transition between treated and untreated cells on histologic assessment. Human tissue generally required more pulses to produce similar effect compared to porcine. Similarly, kidneys displayed tissue specific resistance to BH with increasing resistance from cortex to medulla to the collecting system. Tissue properties that predict resistance to renal BH were evaluated demonstrating correlation between tissue collagen content and tissue resistance. Subsequently, the impact of intervening abdominal wall and ribs on lesion generation ex vivo was evaluated. “Transabdominal” and “transcostal” treatment required approximately 5- and 20-fold greater acoustic power, respectively, to elicit boiling vs. no intervening tissue. [Work supported by NIH T32DK007779, R01EB007643, K01EB015745 and NSBRI through NASA NCC 9-58.]
Historic transducers: Balanced armature receiver (BAR)
Authors: Allen Jont B. , Kim Noori
Published: October 2014

The oldest telephone receiver is the Balanced Armature Receiver (BAR) type, and it is still in use. The original technology goes back to the invention of telephone receiver by A. G. Bell in 1876. Attraction and release of the armature are controlled by the current from the coils, which generates electromagnetic fields [Hunt (1954) Chapter 7, and Beranek and Mellow (2014)]. As the electrical current goes into the electric terminal of the receiver, it generates an AC magnetic field which direction is perpendicular to the current. Due to the polarity between the permanent (DC) magnet field and the generated AC magnetic field, an armature (which sits within the core of the coil and the magnet) feels a force. The very basic principles for explaining this movement in a gyrator, a fifth circuit element introduced by Tellegen in 1948, along with an inductor, a capacitor, a resistor, and a transformer. This component represents the anti-reciprocal characteristic of the system. This study is starting from comparing the BAR type receiver to the moving-coil loud speaker. We believe that this work will provide a fundamental and clear insight into this type of BAR system.
Radiation from wedges of a power law profile
Authors: Remillieux Marcel C. , Anderson Brian E. , Ulrich Timothy J. , Le Bas Pierre-Yves
Published: October 2014

The large impedance contrast between bulk piezoelectric disks and air does not allow for efficient coupling of sound radiation from the piezoelectric into air. Here, we present the idea of using wedges of power law profiles to more efficiently radiate sound into air. Wedges of power law profiles have been used to provide absorption of vibrational energy in plates, but their efficient radiation of sound into air has not been demonstrated. We present numerical modeling and experimental results to demonstrate the concept. The wedge shape provides a gradual impedance contrast as the wave travels down the tapering of the wedge, while the wave speed also continually slows down. For an ideal wedge that tapers down to zero thickness, the waves become trapped at the tip and the vibrational energy can only radiate into the surrounding air. [This work was supported by institutional support [Laboratory Directed Research and Development (LDRD)] at Los Alamos National Laboratory.]
Acoustical transduction in two-dimensional piezoelectric array
Authors: Nusierat Ola , Cremaldi Lucien , Ostrovskii Igor
Published: October 2014

The acoustical transduction in an array of ferroelectric domains with alternating piezoelectric coefficients is characterized by multi-frequency resonances, which occur at the boundary of the acoustic Brillouin zone (ABZ). The resonances correspond to two successive domain excitations in the first and second ABZ correspondingly, where the speed of ultrasound is somewhat different. An important parameter for acoustical transduction is the electric impedance Z. The results of the theoretical and experimental investigations of Z in a periodically poled LiNbO3 are presented. The magnitude and phase of Z depend on the array parameters including domain resonance frequency and domain number; Z of arrays consisting of up to 88 0.45-mm-long domains in the zx-cut crystal are investigated. The strong changes in Z-magnitude and phase are observed in the range of 3–4 MHz. The two resonance zones are within 3.33 ± 0.05 MHz and 3.67± 0.05 MHz. The change in domain number influences Z and its phase. By varying the number of inversely poled domains and resonance frequencies, one can significantly control/change the electrical impedance of the multidomain array. The findings may be used for developing new acoustic sensors and transducers.
Investigation of piezoelectric bimorph bender transducers to generate and receive shear waves
Authors: McNeese Andrew R. , Lee Kevin M. , Ballard Megan S. , Muir Thomas G. , Costley R. Daniel
Published: October 2014

This paper further demonstrates the ability of piezoceramic bimorph bender elements to preferentially generate and receive near-surface shear waves for in situ sediment characterization measurements, in terrestrial as well as marine clay soils. The bimorph elements are housed in probe transducers that can manually be inserted into the sediment and are based on the work of Shirley [J. Acoust. Soc. Am. 63(5), 1643–1645 (1978)] and of Richardson et al. [Geo.—Marine Letts. 196–203 (1997)]. The transducers can discretely generate and receive horizontally polarized shear waves, within their bimorph directivity patterns. The use of multiple probes allows one to measure the shear wave velocity and attenuation parameters in the sediment of interest. Measured shear wave data on a hard clay terrestrial soil, as well as on soft marine sediments, are presented. These parameters along with density and compressional wave velocity define the elastic moduli (Poisson’s ratio, shear modulus, and bulk modulus) of the sediment, which are of interest in various areas of geophysics, underwater acoustics, and geotechnical engineering. Discussion will focus on use of the probes in both terrestrial and marine sediment environments. [Work supported by ARL:UT Austin.]
Multi-mode seismic source for underground application
Authors: ounadjela abderrhamane , Valero Henri Pierre , Auchere Jean christophe , Moyal Olivier
Published: October 2014

A new multi-mode downhole acoustic source has been designed to fulfill requirements of oil business. Three acoustic modes of radiation, i.e., monopole, dipole, and quadruple modes, respectively, are considered to assess the properties of the oil reservoir. Because of the geometry of the well it is challenging to design an efficient and effective powerful device. This new source uses an apparatus to convert the axial motion of the four motors distributed on the azimuth into a radial one. In order to make this conversion effective, the axial motion transformation into a radial one is performed thanks to a rod rolling on a cone; this conversion minimizes the loss by friction and is very effective. The conversion apparatus is also exploited to match the acoustic impedance of the surrounding medium. This new design is described in this paper as well as intensive modeling which allowed optimizing this multi-mode source device. Experimental data is in a good agreement with numerical modeling.
Sound characteristics of the caxirola when used by different uninstructed users
Authors: Pozzer Talita , Paul Stephan
Published: October 2014

While originally developed to be the official musical instrument of the 2014 Soccer World Cup the caxirola was banned form the stadiums as could be thrown into the field by angry spectators. Nevertheless, outside the stadiums the caxirola was still used, thus an already started investigation into the acoustics of the caxirola was concluded. At a previous ASA meeting we presented the sound power level (SWL) of the caxirola only for the two most typical ways of use. Now we present data on the sound pressure level close to the user’s ears (SPLcue) and the SWL, both measured in a reverberation room, from 30 subjects that used the caxirola according their understanding. It was found that the total SPLcue vary from 78 dB(A) up to 95 dB(A) and the global SWL of the caxirola varies from 72 dB until 84 dB. The distribution is not normal, them the SWL has 79 dB(A) as median, that is very similar of the result obtained at the previous study. The SPLcue and the SPL measured for calculating the SWL are differents. This probably due to the distance variation between the source and the ear of user causing a near field some times.