bluuebunny/crossref_metadata_2025 huggingface dataset:
Low frequency propagation experiments in Currituck Sound
Authors: Costley Richard D. , Hathaway Kent K. , McNeese Andrew , Muir Thomas G. , Smith Eric , De Jesus Diaz Luis
Published: October 2014

In water depths on the order of a wavelength, sound propagates with considerable involvement of the bottom, whose velocities and attenuation vary with depth into the sediment. In order to study propagation in these types of environments, experiments were conducted in Currituck Sound on the Outer Banks of North Carolina using a Combustive Sound Source (CSS) and bottom mounted hydrophones and geophones as receivers. The CSS was deployed at a depth of approximately 1 meter and generated transient signals, several wavelengths long, at frequencies around 300 Hz. The results are used to determine transmission loss in water depths of approximately 3 meters, as well as to examine the generation and propagation of Sholte type interface waves. The measurements are compared to numerical models generated with a two-dimensional finite-element code. [Work supported by the U.S. Army Engineer Research and Development Center. Permission to publish was granted by Director, Geotechnical & Structures Laboratory.]
Results from a scale model acoustic propagation experiment over a translationally invariant wedge
Authors: Sagers Jason D.
Published: October 2014

A 1:7500 scale underwater acoustic propagation experiment was conducted in a laboratory tank to investigate three-dimensional (3D) propagation effects, with the objective of providing benchmark quality data for comparison with numerical models. A computer controlled positioning system accurately moves the receiving hydrophone in 3D space while a stationary source hydrophone emits band-limited pulse waveforms between 200 kHz and 1 MHz. The received time series can be post-processed to estimate travel time, transmission loss, and vertical and horizontal arrival angle. Experimental results are shown for a 1.22 × 2.13 m bathymetric part possessing both a flat bottom bathymetry and a translationally invariant wedge with a 10° slope. Comparisons between the experimental data and numerical models are also shown. [Work supported by ONR.]
Numerical modeling of measurements from an underwater scale-model tank experiment
Authors: Ballard Megan S. , Sagers Jason D.
Published: October 2014

Scale-model tank experiments are beneficial because they offer a controlled environment in which to make underwater acoustic propagation measurements, which is helpful when comparing measured data to calculations from numerical propagation models. However, to produce agreement with the measured data, experimental details must be carefully included in the model. For example, the frequency-dependent transmitting and receiving sensitivity and vertical directionality of both hydrophones must be included. In addition, although it is possible to measure the geometry of the tank experiment, including water depth and source and receiver positions, positional uncertainty exists due to the finite resolution of the measurements. The propagated waveforms from the experiment can be used to resolve these parameters using inversion techniques. In this talk, model-data comparisons of measurements made in a 1:7500 scale experiment are presented. The steps taken to produce agreement between the measured and modeled data are discussed in detail for both range-independent and range-dependent configurations.
Role of binding energy (edge-to-face contact of mineral platelets) in the acoustical properties of oceanic mud sediments
Authors: Pierce Allan D. , Siegmann William L.
Published: October 2014

A theory for mud sediments presumes a card-house model, where the platelets arrange themselves in a highly porous configuration; electrostatic forces prevent face-to-face contacts. The primary type of contact is where the edge of one platelet touches a face of another. Why such is not also prevented by electrostatic forces is because of van der Waals (vdW) forces between the molecular structures within the two platelets. A quantitative assessment is given of such forces, taking into account the atomic composition and crystalline structure of the platelets, proceeding from the London theory of interaction between non-polar molecules. Double-integration over both platelets leads to a quantitative and simple prediction for the potential energy of vdW interaction as a function of the separation distance, edge-from-face. At moderate nanoscale distances, the resulting force is attractive and is much larger than the electrostatic repulsion force. But, at very close (touching) distances, the intermolecular force becomes also repulsive, so that there is a minimum potential energy, which is identified as the binding energy. This finite binding energy, given a finite environmental temperature, leads to some statistical mechanical theoretical implications. Among the acoustical implications is a relaxation mechanism for the attenuation of acoustic waves propagating through mud.
Near bottom self-calibrated measurement of normal reflection coefficients by an integrated deep-towed camera/acoustical system
Authors: Chiu Linus , Wang Chau-Chang , Chen Hsin-Hung , Chang Andrea Y. , Chu Chung-Ray
Published: October 2014

Normal incidence echo data (bottom reflection) can provide acoustic reflectivity estimates used to predict sediment properties with using seabed sediment models. Accuracy of normal reflection coefficient measurement thus become very significant to the bottom inversion result. A deep-towed camera platform with acoustical recording system, developed by the Institution of Undersea Technology, National Sun Yat-sen University, Taiwan, is capable of photographically surveying the seafloor in near scope and acquiring sound data. The real time data transference, including photography (optics) and reflection measurement (acoustics) can be implemented in the same site simultaneously. The deep-towed camera near the bottom was used in several experiments in the southwestern sea off Taiwan in 2014 to acquire acoustic LFM signal sent by surface shipboard source as incident signal as well as the seafloor reflections at frequency bands within 4–6 kHz. The error produced by compensating the roll-off of altitude of vehicle (propagation loss) can be eliminated, which is considered as near bottom self-calibrated measurement for normal reflection coefficient. The collected reflection coefficients were used to inverting the sediment properties with using the Effective Density Fluid model (EDFM), manifested by the coring and camera images. [This work is sponsored by the Ministry of Science and Technology of Taiwan.]
Backscattering from an obstacle immersed in an oceanic waveguide covered with ice
Authors: Grigorieva Natalie S. , Mikhaylova Daria A. , Ostrovskiy Dmitriy B.
Published: October 2014

The presentation describes the theory and implementation issues of modeling of the backscattering from an obstacle immersed in a homogeneous, range-independent waveguide covered with ice. An obstacle is assumed to be spherical, rigid or fluid body. A bottom of the waveguide and an ice cover are fluid, attenuating half-space. The properties of an ice cover and a scatterer may coincide. To calculate the scattering coefficients of a sphere [R. M. Hackman et al., J. Acoust. Soc. Am. 84, 1813–1825 (1988)], the normal mode evaluation is applied. A number of normal modes forming the backscattering field is determined by a given directivity of the source. The obtained analytical expression for the backscattered field is applied to evaluate its dependence on source frequency, depth of a water layer, bottom and ice properties, and distance between the source and obstacle. Two cases are analyzed and compared: when the upper boundary of a waveguide is sound-soft and when a water layer is covered with ice. Computational results are obtained in a wide frequency range 8–12 kHz for conditions of a shallow water testing area. [Work supported by Russian Ministry of Educ. and Sci., Grant 02.G25.31.0058.]
Emergence of striation patterns in acoustic signals reflected from dynamic surface waves
Authors: Choo Youngmin , Seong Woojae , Song Heechun
Published: October 2014

A striation pattern can emerge in high-frequency acoustic signals interacting with dynamic surface waves. The striation pattern is analyzed using a ray tracing algorithm for both a sinusoidal and a rough surface. With a source or receiver close to the surface, it is found that part of the surface on either side of the specular reflection point can be illuminated by rays, resulting in time-varying later arrivals in channel impulse response that form the striation pattern. In contrast to wave focusing associated with surface wave crests, the striation occurs due to reflection off convex sections around troughs. Simulations with a sinusoidal surface show both an upward (advancing) and downward (retreating) striation patterns that depend on the surface-wave traveling direction and the location of the illuminated area. In addition, the striation length is determined mainly by the depth of the source or receiver, whichever is closer in range to the illuminated region. Even with a rough surface, the striation emerges in both directions. However, broadband (7–13 kHz) simulations in shallow water indicate that the longer striation in one direction is likely pronounced against a quiet noise background, as observed from at-sea experimental data. The simulation is extended for various surface wave spectra and it shows consistent patterns.
Acoustics in collaborative open office environments
Authors: LoVerde John J. , Rawlings Samantha , Dong David W.
Published: October 2014

Historically, acoustical design for open office environments focuses on creating workspaces that maximize speech privacy and minimize aural distractions. Hallmark elements of the traditional open office environment include barriers, sound-absorptive surfaces, and consideration of workspace orientation, size, and background sound level. In recent years, development of “collaborative” office environments has been desired, which creates an open work setting, allowing immediate visual and aural communication between team members. This results in reducing the size of workstations, lowering barriers, and reducing distance between occupants. Additionally, group meeting areas have also become more open, with the popularization of “huddle zones” where small groups hold meetings in an open space adjacent to workstations rather than within enclosed conference rooms. Historically, this type of office environment would have poor acoustical function, with limited speech privacy between workstations and minimal attenuation of distracting noises, leading to occupant complaints. However, these collaborative open office environments function satisfactorily and seem to be preferred by occupants and employers alike. This paper investigates the physical acoustical parameters of collaborative open office spaces.
Lessons learned in reconciling high performance building design with acoustical comfort
Authors: Smith Valerie , Salter Ethan
Published: October 2014

In today's diverse workplace, “the one size fits all” approach to office design is becoming less prevalent. The indoor environmental quality of the workplace is important to owners and occupants. Architects are developing innovative ways to encourage interaction and collaboration while also increasing productivity. Many of these ideas are at odds with the traditional acoustical approaches used for office buildings. Employees are asking for, and designers are incorporating, amenities such as kitchens, game rooms, and collaboration spaces into offices. Architects and end users are becoming increasingly aware of acoustics in their environment. The U.S. General Services Administration (GSA) research documents, as well as those from other sources, discusses the importance of acoustics in the workplace. Private companies are also creating acoustical standards documents for use in design of new facilities. As more buildings strive to achieve sustainable benchmarks (whether corporate, common green building rating systems such as LEED, or code-required) the understanding of the need for acoustical items (such as sound isolation, speech privacy, and background noise) also become critical. The challenge is how to reconcile sustainable goals with acoustical features. This presentation discusses several of the approaches that our firm has recently used in today’s modern office environment.
Acoustics in an office building
Authors: Beristain Sergio
Published: October 2014

New building techniques tend to make better use of materials, temperature, and energy, besides costs. A building company had to plan the adaptation of a very old building with the purpose to install private offices of different sizes in each floor, in order to take advantage of a large solid construction, reducing building time, total weight, etc., while at the same time fulfilling new requirements related with comfort, general quality, functionality, and economy. Among several other topics, sound and vibrations had to be considered during the process, including noise control and speech privacy, because a combination of private rooms and open plan offices were needed, as well as limiting environmental vibrations. Aspects such as the use of light weight materials and the installation of many climate conditioning systems were needed, which were dealt along the project in the search for a long lasting and low maintenance costs construction.
A case history in architectural acoustics: Security, acoustics, the protection of personally identifiable information (PII), and accessibility for the disabled
Authors: Ellis Donna A.
Published: October 2014

This paper discusses the re-design of a field office to enhance the protection of Personally Identifiable Information (PII), physical security, and accessibility for the disabled at the Social Security Administration (SSA) field office in Roxbury, MA. The study, and its results can be used at federal, civil, and private facilities where transaction window type public interviews occur. To protect the public and its staff, the SSA has mandated heightened security requirements in all field offices. The increased security measures include: Installation of barrier walls to provide separation between the public and private zones; maximized lines of sight, and increased speech privacy for the protection of PII. This paper discusses the use of the Speech Transmission Index (STI) measurement method used to determine the post construction intelligibility of speech through the transaction window, the acoustical design of the windows and their surrounding area, how appropriate acoustic design helps safeguard personal and sensitive information so that it may be securely communicated verbally, as well as improved access for the disabled community, especially the hearing impaired.
Exploring the impacts of consistency in sound masking
Authors: Moeller Niklas , Doedens Ric
Published: October 2014

Electronic sound masking systems control the noise side of the signal-to-noise ratio in interior environments. Their effectiveness relates directly to how consistently the specified masking curve is achieved. Current system specifications generally allow a relatively wide range in performance, in large part reflecting expectations set by legacy technologies. This session presents a case study of sound masking measurements and speech intelligibility calculations conducted in office spaces. These are used as a foundation to discuss the impacts of local inconsistencies in the masking sound and to begin a discussion of appropriate performance requirements for masking systems.
Evaluating the effect of prominent tones in noise on human task performance
Authors: Lee Joonhee , Wang Lily M.
Published: October 2014

Current noise guidelines for the acoustic design of offices generally specify limits on loudness and sometimes spectral shape, but do not typically address the presence of tones in noise as may be generated by building services equipment. Numerous previous studies indicate that the presence of prominent tones is a significant source of deteriorating indoor environmental quality. Results on how prominent tones in background noise affect human task performance, though, are less conclusive. This paper presents results from recent studies at Nebraska on how tones in noise may influence task performance in a controlled office-like environment. Participants were asked to complete digit span tasks as a measure of working memory capacity, while exposed to assorted noise signals with tones at varying frequencies and tonality levels. Data on the percent correct and reaction time in which participants responded to the task are analyzed statistically. The results can provide guidance for setting limits on the tonality levels in offices and other spaces in which building users must be task-productive.
Optimal design of multi-layer microperforated sound absorbers
Authors: Kim Nicholas , Xue Yutong , Bolton J. S.
Published: October 2014

Microperforated polymer films can offer and effective solution when it is desired to design fiber-free sound absorption systems. The acoustic performance of the film is determined by hole size and shape, by the surface porosity, by the mass per unit area of the film, and by the depth of the backing air layer. Single sheets can provide good absorption over a one of two octave range, but if absorption over a broader range is desired, it is necessary to use multilayer treatments. Here the design of a multilayer sound absorption system is described, where the film is considered to have a finite mass per unit area and also to have conical perforations. It will be shown that it is possible to design compact absorbers that yield good performance over the whole speech interference range. In the course of the optimization it has been found that there is a tradeoff between cone angle and surface porosity. The design of lightweight, multilayer functional absorbers will also be described, and it will be shown, for example, that it is possible to design systems that simultaneously possess good sound absorption and barrier characteristics.
Foraging among acoustic clutter and competition: Vocal behavior of paired big brown bats
Authors: Warnecke Michaela , Chiu Chen , Xian Wei , Cechetto Clement , Moss Cynthia F.
Published: October 2014

In their natural environment, big brown bats forage for small insects in open spaces, as well as in the presence of acoustic clutter. While searching and hunting for prey, these bats experience sonar interference not only from densely cluttered environments, but also through calls from other conspecifics foraging close-by. Previous work has shown that when two bats fly in a relatively open environment, one of them may go silent for extended periods of time (Chiu et al. 2008), which may serve to minimize such sonar interference between conspecifics. Additionally, big brown bats have been shown to adjust frequency characteristics of their vocalizations to avoid acoustic interference from conspecifics (Chiu et al., 2009). It remains an open question, however, in what way environmental clutter and the presence of conspecifics influence the bat’s call behavior. By recording multichannel audio and video data of bats engaged in insect capture in an open and a cluttered space, we quantified the bats’ vocal behavior. Bats were flown individually and in pairs in an open and cluttered room, and the results of this study shed light on the strategies animals employ to negotiate a complex and dynamic environment.
Sensory escape from a predator–prey arms race: Low amplitude biosonar beats moth hearing
Authors: Goerlitz Holger R. , ter Hofstede Hannah M. , Zeale Matt , Jones Gareth , Holderied Marc W.
Published: October 2014

Ultrasound-sensitive ears evolved in many nocturnal insects, including some moths, to detect bat echolocation calls and evade capture. Although there is evidence that some bats emit echolocation calls that are inconspicuous to eared moths, it is difficult to determine whether this was an adaptation to moth hearing or originally evolved for a different purpose. Here we present the first example of an echolocation counterstrategy to overcome prey hearing at the cost of reduced detection distance, providing an example of a predator outcompeting its prey despite the life-dinner-principle. Aerial-hawking bats generally emit high-amplitude echolocation calls to maximize detection range. Using comparative acoustic flight-path tracking of free-flying bats, we show that the barbastelle, Barbastella barbastellus, emits calls that are 10 to 100 times lower in amplitude than those of other aerial hawking bats. Model calculations demonstrate that only bats emitting such low-amplitude calls hear moth echoes before their calls are conspicuous to moths. We confirm that the barbastelle remains undetected by moths until close and preys mainly on eared moths, using moth neurophysiology in the field and fecal DNA analysis. This adaptive stealth echolocation allows the barbastelle to access food resources that are difficult to catch for high-intensity bats.
Cues, creaks, and decoys: Using underwater acoustics to study sperm whale interactions with the Alaskan black cod longline fishery
Authors: Thode Aaron , Straley Janice , Wild Lauren , Sarkar Jit , O'Connell Victoria , Falvey Dan
Published: October 2014

For decades off SE Alaska, sperm whales have located longlining fishing vessels and removed, or “depredated,” black cod from the hauls. In 2004, the Southeast Alaska Sperm Whale Avoidance Project (SEASWAP) began deploying passive acoustic recorders on longline fishing gear in order to identify acoustic cues that may alert whales to fishing activity. It was found that when hauling, longlining vessels generate distinctive cavitation sounds, which served to attract whales to the haul site. The combined use of underwater recorders and video cameras also confirmed that sperm whales generated “creak/buzz” sounds while depredating, even under good visual conditions. By deploying recorders with federal sablefish surveys over two years, a high correlation was found between sperm whale creak rate detections and visual evidence for depredation. Thus passive acoustics is now being used as a low-cost, remote sensing method to quantify depredation activity in the presence and absence of various deterrents. Two recent developments will be discussed in detail: the development and field testing of acoustic “decoys” as a potential means of attracting animals away from locations of actual fishing activity, and the use of “TadPro” cameras to provide combined visual and acoustic observations of longline deployments. [Work supported by NPRB, NOAA, and BBC.]
Follow the food: Effects of fish and zooplankton on the behavioral ecology of baleen whales
Authors: Warren Joseph , Parks Susan E. , Pearson Heidi , Owen Kylie
Published: October 2014

Active acoustics were used to collect information on the type, distribution, and abundance of baleen whale prey species such as zooplankton and fish at fine spatial (sub-meter) and temporal (sub-minute) scales. Unlike other prey measurement methods, scientific echosounder surveys provide prey data at a resolution similar to what a predator would detect in order to efficiently forage. Data from several studies around the world shows that differences in prey type or distribution result in distinctly different baleen whale foraging behaviors. Humpback whales in coastal waters of Australia altered their foraging pattern depending on the presence and abundance of baitfish or krill. In Southeast Alaska, humpback whales foraged cooperatively or independently depending on prey type and abundance. Humpback whales in the Northwest Atlantic with multiple prey species available foraged on an energetically costly (and presumably rewarding) species. The vertical and horizontal movements of North Atlantic right whales in Cape Cod Bay were strongly correlated with very dense aggregations of copepods. In all of these cases, active acoustics were used to estimate numerical densities of the prey, which provides quantitative information about the energy resource available to foraging animals.
Understanding the relationship between ice, primary producers, and consumers in the Bering Sea
Authors: Miksis-Olds Jennifer L. , Stauffer Stauffer A.
Published: October 2014

Technology has progressed to the level of allowing for investigations of trophic level interactions over time scales of months to years which were previously intractable. A combination of active and passive acoustic technology has been integrated into sub-surface moorings on the Eastern Bering Sea shelf, and seasonal transition measurements were examined to better understand how interannual variability of hydrographic conditions, phytoplankton biomass, and acoustically derived consumer abundance and community structure are related. Ocean conditions were significantly different in 2012 compared to relatively similar conditions in 2009, 2010, and 2011. Differences were largely associated with variations in sea ice extent, thickness, retreat timing, and water column stratification. There was a high degree of variability in the relationships between different classes of consumers and hydrographic condition, and evidence for intra-consumer interactions and trade-offs between different size classes was apparent. Phytoplankton blooms in each year stimulated different components of the consumer population. Acoustic technology now provides the opportunity to explore the ecosystem dynamics in a remote, ice-covered region that was previously limited to ship-board measurements during ice-free periods. The new knowledge we are gaining from remote, long-term observations is resulting in a re-examination of previously proposed ecosystem theories related to the Bering Sea.
Temporal and spatial patterns of marine soundscape in a coastal shallow water environment
Authors: Guan Shane , Lin Tzu-Hao , Vignola Joseph F. , Chou LIen-Siang , Judge John A.
Published: October 2014

Underwater acoustic recordings were made at two coastal shallow water locations, Yunlin (YL) and Waishanding (WS), off Taiwan between June and December 2012. The purpose of the study was to establish soundscape baselines and characterize the acoustic habitat of the critically endangered Eastern Taiwan Strait Chinese white dolphin by investigating: (1) major contributing sources that dominant the soundscape, (2) temporal, spatial, and spectral patterns of the soundscape, and (3) correlations of known sources and their potential effects on dolphins. Results show that choruses from croaker fish (family Sciaenidae) were dominant sound sources in the 1.2–2.4 kHz frequency band for both locations at night, and noises from container ships in the 150–300 Hz frequency band define the relative higher broadband sound levels at YL. In addition, extreme temporal variation in the 150–300 Hz frequency band were observed at WS, which was shows to be linked to the tidal cycle and current velocity. Furthermore, croaker choruses are found to be most intense around the time of high tide at night, but not so around the time of low tide. These results illustrate interrelationships among different biotic, abiotic, and anthropogenic environmental elements that shape the unique fine-scale soundscape in a coastal environment.
Ocean acoustics education—A perspective from 1970 to the present
Authors: Baggeroer Arthur B.
Published: October 2014

A very senior ocean acoustician is attributed with the quote to the effect “one does not start in ocean acoustics, but rather ends up in it.” This may well summarize the issues confronting education in ocean acoustics. Acoustics were part of the curriculum in physics departments, whereas now it is spread across many departments. Acoustics and perhaps ocean acoustics are most often found in mechanical or ocean engineering departments, but seldom in physics. Almost all our pioneers from the WWII era were educated in physics and some more recently in engineering departments. Yet, only a few places maintained in depth curricula in ocean acoustics. Most education was done by one on one mentoring. Now the number of students is diminishing, whether because of perception of employment opportunities or the number of available assistantships is uncertain. ONR is the major driver in ocean acoustics for supporting graduate students. The concern about this is hardly new. Twenty plus years ago this was codified as part of the so called “Lackie Report” establishing ocean acoustics as “Navy unique” giving it a priority as a “Navy National Need” (NNR). With fewer students enrolled in ocean acoustics administrators at universities are really balking at sponsoring faculty slots, so there are very significant issues arising for an education in ocean acoustics. Perhaps, reverting to the original model of fundamental training in a related discipline followed by on the job training may be the only option for the future.
Graduate studies in underwater acoustics at the University of Washington
Authors: Dahl Peter H. , Odom Robert I. , Simmen Jeffrey A.
Published: October 2014

The University of Washington through its Departments of Mechanical and Electrical Engineering (College of Engineering), Department of Earth and Space Sciences, and School of Oceanography (College of the Environment), and by way of its Applied Physics Laboratory, which links all four of these academic units, offers a diverse graduate education experience in underwater acoustics. A summary is provided of the research infrastructure, primarily made available through Applied Physics Laboratory, which allows for ocean going and arctic field opportunities, and course options offered through the four units that provide the multi-disciplinary background essential for graduate training in the field of underwater acoustics. Students in underwater acoustics can also mingle in or extend their interests into medical acoustics research. Degrees granted include both the M.S and Ph.D.
Acoustical Oceanography and Underwater Acoustics; their role in the Pennsylvania State University Graduate Program in Acoustics
Authors: Bradley David , Sparrow Victor
Published: October 2014

The Pennsylvania State University Graduate Program in Acoustics has a long and successful history in Acoustics Education. A brief history together with the current status of the program will be discussed. An important aspect of the program has been the strong role of the Applied Research Laboratory, both in support of the program as well as for the graduate students enrolled. Presentation includes details of course content, variability to fit student career goals and program structure, including resident and distance education opportunities. The future of the program at Penn State will also be addressed.
Ocean acoustics at the University of Victoria
Authors: Chapman Ross
Published: October 2014

This paper describes the academic program in Ocean Acoustics and Acoustical Oceanography at the University of Victoria in Canada. The program was established when a Research Chair in Ocean Acoustics consisting of two faculty members was funded in 1995 by the Canadian Natural Sciences and Engineering Research Council (NSERC). The Research Chair graduate program offered two courses in Ocean Acoustics, and courses in Time Series Analysis and Inverse Methods. Funding for students was obtained entirely through partnership research programs with Canadian marine industry, the Department of National Defence in Canada and the Office of Naval Research. The program was successful in graduating around 30 M.Sc. and Ph.D. students to date, about half of whom were Canadians. Notably, all the students obtained positions in marine industry, government, or academia after their degrees. The undergraduate program consisted of one course in Acoustical Oceanography at the senior level (3rd year) that was designed to appeal to students in physics, biology, and geology. The course attracted about 30 students each time, primarily from biology. The paper concludes with perspectives on difficulties in operating an academic program with a low critical mass of faculty and in isolation from colleagues in the research field.
Ocean acoustics away from the ocean
Authors: Dowling David R.
Published: October 2014

Acoustics represents a small portion of the overall educational effort in engineering and science, and ocean acoustics is one of many topic areas in the overall realm of acoustics. Thus, maintaining teaching and research efforts involving ocean acoustics is challenging but not impossible, even at a university that is more than 500 miles from the ocean. This presentation describes the author's two decades of experience in ocean acoustics education and research. Success is possible by first attracting students to acoustics, and then helping them wade into a research topic in ocean acoustics that overlaps with their curiosity, ambition, or both. The first step occurs almost naturally since college students' experience with their ears and voice provides intuition and motivation that allows them to readily grasp acoustic concepts and to persevere through mathematical courses. The second step is typically no more challenging since ocean acoustics is a leading and fascinating research area that provides stable careers. Plus, there are even some advantages to studying ocean acoustics away from the ocean. For example, matched-field processing, a common ocean acoustic remote sensing technique, appears almost magical to manufacturing or automotive engineers when applied to assembly line and safety problems involving airborne sound.
Office of Naval Research special research awards in ocean acoustics
Authors: Headrick Robert H.
Published: October 2014

The Ocean Acoustics Team of the Office of Naval Research manages the Special Research Awards that support graduate traineeship, postdoctoral fellowship, and entry-level faculty awards in ocean acoustics. The graduate traineeship awards provide for study and research leading to a doctoral degree and are given to individuals who have demonstrated a special aptitude and desire for advanced training in ocean acoustics or the related disciplines of undersea signal processing, marine structural acoustics and transducer materials science. The postdoctoral fellowship and entry-level faculty awards are similarly targeted. These programs were started as a component of the National Naval Responsibility in Ocean Acoustics to help ensure a stable pipeline of talented individuals would be available to support the needs of the Navy in the future. They represent only a fraction of the students, postdocs, and early faculty researchers that are actively involved the basic research supported by the Ocean Acoustics Program. A better understanding of the true size of the pipeline and the capacity of the broader acoustics related Research and Development community to absorb the output is needed to maintain a balance in priorities for the overall Ocean Acoustics Program.
Underwater acoustics education at the University of Texas at Austin
Authors: Isakson Marcia J. , Hamilton Mark F. , Penrod Clark S. , Pestorius Frederick M. , Wilson Preston S.
Published: October 2014

The University of Texas at Austin has supported education and research in acoustics since the 1930s. The Cockrell School of Engineering currently offers a wide range of graduate courses and two undergraduate courses in acoustics, not counting the many courses in hearing, speech, seismology, and other areas of acoustics at the university. An important adjunct to the academic program in acoustics has been the Applied Research Laboratories (ARL). Spun off in 1945 from the WW II Harvard Underwater Sound Laboratory (1941–1949) and founded as the Defense Research Laboratory, ARL is one of five University Affiliated Research Centers formally recognized by the US Navy for their prominence in underwater acoustics research and development. ARL is an integral part of UT Austin, and this symbiotic combination of graduate and undergraduate courses, and laboratory and field work, provides one of the leading underwater acoustics education programs in the nation. In this talk, the underwater acoustics education program will be described with special emphasis on the underwater acoustics course and its place in the larger acoustics program. Statistics on education, funding, and placement of graduate students in the program will also be presented.
Acoustical Oceanography and Underwater Acoustics Graduate Programs at the Scripps Institution of Oceanography of the University of California, San Diego
Authors: Kuperman William A.
Published: October 2014

The Scripps Institution of Oceanography (SIO) of the University of California, San Diego (UCSD), has graduate programs in all areas of acoustics that intersect oceanography. These programs are associated mostly with internal SIO divisions that include the Marine Physical Laboratory, Physical Oceanography, Geophysics, and Biological Oceanography as well as SIO opportunities for other UCSD graduate students in the science and engineering departments. Course work includes basic wave physics, graduate mathematics, acoustics and signal processing, oceanography and biology, digital signal processing, and geophysics/seismology. Much of the emphasis at SIO includes at-sea experience. Recent examples of thesis research has been in marine mammal acoustics, ocean tomography and seismic/acoustic inversion methodology, acoustical signal processing, ocean ambient noise inversion, ocean/acoustic exploration, and acoustic sensing of the air-sea interaction. An overview of the SIO/UCSD graduate program is presented.
Underwater acoustics education at Portland State University
Authors: Siderius Martin , Zurk Lisa M.
Published: October 2014

The Northwest Electromagnetics and Acoustics Research Laboratory (NEAR-Lab) is in the Electrical and Computer Engineering Department at Portland State University (PSU) in Portland, Oregon. The NEAR-Lab was founded in 2005 and is co-directed by Lisa M. Zurk and Martin Siderius. A primary interest is underwater acoustics, and students at undergraduate and graduate levels (occasionally also high school students) regularly participate in research. This is synergistic with underwater acoustics education at PSU, which includes a course curriculum that provides opportunities for theoretical and experimental research and multiple course offerings at both the undergraduate and graduate level. The research generally involves modeling and analysis of acoustic propagation and scattering, acoustic signal processing, algorithm development, environmental acoustics, and bioacoustics. The lab maintains a suite of equipment for experimentation including hydrophone arrays, sound projectors, a Webb Slocum glider, an electronics lab, and an acoustic tank. Large-scale experiments that include student participation have been routinely conducted by successful collaborations such as with the APL-University of Washington, NATO Centre for Maritime Research and Experimentation, and the University of Hawaii. In this talk, the state of the PSU underwater acoustics program will be described along with the courses offered, research activities, experimental program, collaborations, and student success.
Ocean acoustics at the University of Rhode Island
Authors: Potty Gopu R. , Miller James H.
Published: October 2014

The undergraduate and graduate program in Ocean Engineering at the University of Rhode Island is one of the oldest such programs in the United States. This program offers Bachelors, Masters (thesis and non-thesis options), and Ph.D. degrees. At the undergraduate level, students are exposed to ocean acoustics through a number of required and elective courses, laboratory and field work, and capstone projects. Examples of student projects will be presented. At the graduate level, students can specialize in several areas including geoacoustic inversion, propagation modeling, marine mammal acoustics, ocean acoustic instrumentation, transducers, etc. A historical review of the evolution of ocean acoustics education in the department will be presented. This will include examples of some of the research carried out by different faculty and students over the years, enrollment trends, collaborations, external funding, etc. Many graduates from the program hold faculty positions at a number of universities in the US and abroad. In addition, graduates from the ocean acoustics program at URI are key staff at many companies and organizations. A number of companies have spun off the program in the areas of forward-looking sonar, sub-bottom profiling, and other applications. The opportunities and challenges facing the program will be summarized.
An underwater acoustics program far from the ocean: The Georgia Tech case
Authors: Sabra Karim G.
Published: October 2014

The underwater acoustics education program at the Georgia Institute of Technology (Georgia Tech) is run by members of the Acoustics and Dynamics research area group from the School of Mechanical Engineering. We will briefly review the scope of this program in terms of education and research activities as well as discuss current challenges related to the future of underwater acoustics education.
Graduate education in ocean acoustics at Rensselaer Polytechnic Institute
Authors: Siegmann William L.
Published: October 2014

Doctoral and master’s students in Rensselaer’s Department of Mathematical Sciences have had opportunities for research in Ocean Acoustics since 1957. Since then only one or two faculty members at any time were directly involved with OA education. Consequently, collaboration with colleagues at other centers of OA research has been essential. The history will be briefly reviewed, focusing on the education of a small group of OA doctoral students in an environment with relatively limited institutional resources. Graduate education in OA at RPI has persisted because of sustained support by the Office of Naval Research.
Summary of panel discussion on education in Acoustical Oceanography and Underwater Acoustics
Authors: Lavery Andone C.
Published: October 2014

Following the presentations by the speakers in session, a panel discussion will offer the platform for those in the audience, particularly those from Institutions and Universities that did not formally participate in the session but have active education programs in Acoustical Oceanography and/or Underwater Acoustics, to ask relevant questions and contribute to the assessment of the national health of education in the fields of Acoustical Oceanography and Underwater Acoustics. A summary of the key points presented in the special sessions and panel discussion is provided.
Comparable clinical outcomes with two lithotripters having substantially different acoustic characteristics
Authors: Lingeman James E. , Bhojani Naeem , Williams James C. , Evan Andrew P. , McAteer James A.
Published: October 2014

A consecutive case study was conducted to assess the clinical performance of the Lithogold, an electrohydraulic lithotripter having a relatively low P + and broad focal width (FW) (~20 MPa, ~20 mm), and the electromagnetic Storz-SLX having higher P + and narrower FW (~50 MPa, 3–4 mm). Treatment was at 60 SW/min with follow-up at ~2 weeks. Stone free rate (SFR) was defined as no residual fragments remaining after single session SWL. SFR was similar for the two lithotripters (Lithogold 29/76 = 38.2%; SLX 69/142 = 48.6% p = 0.15), with no difference in outcome for renal stones (Lithogold 20/45 = 44.4%; SLX 33/66 = 50%, p = 0.70) or stones in the ureter (Lithogold 9/31 = 29%; SLX 36/76 = 47.4%, p = 0.08). Stone size did not differ between the two lithotripters for patients who were not stone free (9.1±3.7 mm for Lithogold vs. 8.5±3.5 mm for SLX, P = 0.42), but the stone-free patients in the Lithogold group had larger stones on average than the stone-free patients treated with the SLX (7.6±2.5 mm vs. 6.2±3.2 mm, P = 0.005). The percentage of stones that did not break was similar (Lithogold 10/76 = 13.2%; SLX 23/142 = 16.2%). These data present a realistic picture of clinical outcomes using modern lithotripters, and although the acoustic characteristics of the Lithogold and SLX differ considerably, outcomes were similar. [NIH-DK43881.]
Multiscale model of comminution in shock wave lithotripsy
Authors: Mitran Sorin M. , Sankin Georgy , Zhang Ying , Zhong Pei
Published: October 2014

A previously introduced model for stone comminution in shock wave lithotripsy is extended to include damage produced by cavitation. At the macroscopic, continuum level a 3D elasticity model with time-varying material constants capturing localized damage provides the overall stress field within kidney stone simulants. Regions of high stress are identified and a mesoscopic crack propagation is used to dynamically update localized damage. The crack propagation model in turn is linked with a microscopic grain dynamics model. Continuum stresses and surface pitting is provided by a multiscale cavitation model (see related talk). The overall procedure is capable of tracking stone fragments and surface cavitation of the fragments through several levels of breakdown. Computed stone fragment distributions are compared to experimental results. [Work supported by NIH through 5R37DK052985-18.]
Exploring the limits of treatment used to invoke protection from extracorporeal shock wave lithotripsy induced injury
Authors: Connors Bret A. , Evan Andrew P. , Handa Rajash K. , Blomgren Philip M. , Johnson Cynthia D. , McAteer James A. , Lingeman James E.
Published: October 2014

Previous studies with our juvenile pig model have shown that a clinical dose of 2000 shock waves (SWs) (Dornier HM-3, 24 kV, 120 SWs/min) produces a lesion ~3–5% of the functional renal volume (FRV) of the SW-treated kidney. This injury was significantly reduced (to ~0.4% FRV) when a priming dose of 500 low-energy SWs immediately preceded this clinical dose, but not when using a priming dose of 100 SWs [BJU Int. 110, E1041 (2012)]. The present study examined whether using only 300 priming dose SWs would initiate protection against injury. METHODS: Juvenile pigs were treated with 300 SW’s (12 kV) delivered to a lower pole calyx using a HM-3 lithotripter. After a pause of 10 s, 2000 SWs (24 kV) were delivered to that same kidney. The kidneys were then perfusion-fixed and processed to quantitate the size of the parenchymal lesion. RESULTS: Pigs (n = 9) treated using a protocol with 300 low-energy priming dose SWs had a lesion measuring 0.84±0.43% FRV (mean ± SE). This lesion was smaller than that seen with a clinical dose of 2000 SWs at 24 kV. CONCLUSIONS: A treatment protocol including 300 low-energy priming dose SWs can provide protection from injury during shock wave lithotripsy. [Research supported by NIH grant P01 DK43881.]
Shockwave lithotripsy with renoprotective pause is associated with vasoconstriction in humans
Authors: Lee Franklin , Hsi Ryan , Harper Jonathan D. , Dunmire Barbrina , Bailey Michael , Liu Ziyue , Sorensen Mathew D.
Published: October 2014

A pause early in shock wave lithotripsy (SWL) increased vasoconstriction as measured by resistive index (RI) during treatment and mitigated renal injury in an animal model. The purpose of our study was to investigate whether RI rose during SWL in humans. Prospectively recruited patients underwent SWL of renal stones with a Dornier Compact S lithotripter. The renal protective protocol consisted of treatment at 1 Hz and slow power ramping for the initial 250 shocks followed by a 2 min pause. RI was measured using ultrasound prior to treatment, after 250 shocks, after 750 shocks, after 1500 shocks, and after SWL. A linear mixed-effects model was used to compare RI at the different time points and to account for additional covariates in fifteen patients. RI was significantly higher than baseline for all time points 250 shocks and after. Age, gender, body mass index, and treatment side were not significantly associated with RI. Monitoring for a rise in RI during SWL is possible and may provide real-time feedback as to when the kidney is protected. [Work supported by NIH DK043881, NSBRI through NASA NCC 9-58, and resources from the VA Puget Sound Health Care System.]