bluuebunny/crossref_metadata_2025 huggingface dataset:
Broadband sound generation by flow through a dynamic physical model of the larynx
Authors: Zhang Zhaoyan , Mongeau Luc , Frankel Steven
Published: February 2014

The random component of sound generated by confined jet flows through rubber larynx models was measured for stationary and nonstationary orifice areas. Anechoically terminated rubber hoses upstream and downstream of the orifice minimized acoustic resonance, thereby isolating the source. Radiated sound pressures were recorded, together with static pressures, orifice area, and the mean flow rate. Empirical scaling laws for the radiated sound spectra of jets through stationary orifices of different shapes and areas were first obtained. The walls of the orifice plate were then mechanically driven at frequencies between 50–120 Hz. The periodic component of the radiated acoustic pressure was removed from the microphone signals using ensemble averaging procedures. Statistics of the broadband component of the sound signals were compared for the stationary cases and the nonstationary cases for the same orifice geometry using conditional sampling methods. Very good agreement between the probability density functions was obtained. The instantaneous spectrum of the turbulence-generated sound for nonstationary flows was also found to be comparable to the spectrum of corresponding stationary flows. This confirms the validity of the quasisteady assumption used in aerodynamic models of voice production.
Effect of focus and inter-accent-interval on lexical pitch accents in Japanese
Authors: Kiwako Ito
Published: February 2014

The effect of narrow focus and the size of inter-accent-interval (IAI) on the acoustic prominence of pitch accents in Japanese was investigated by measuring F0 maxima and variance. Subjects produced utterances containing two accented adjectives, with either 0, 1, or 2 syllables between the accents. Each sentence was produced with focus on the first, second, or none of the adjectives. The results show F0 maxima enhancement for the accented syllables under focus regardless of the word position, and attenuation in F0 movement peri-focally. Such effect resembles the pattern in Dutch [Rump and Collier, Language Speech 39, 1–17 (1996)] more than that in English [Eady and Cooper, J. Acoust. Soc. Am. 80, 402–415 (1986)]. The F0 variance during the first accent was significantly smaller in the presence of an accent clash, i.e., IAI=0. This pattern bears an interesting similarity to the stress-clash phenomenon [Cooper and Eady, J. Memory Language 25, 369–384 (1986)]. The focus effect was larger than the IAI effect, and they did not interact, i.e., the focus effect was not larger for further apart accents. This suggests that, in Japanese, the pragmatic function of pitch prevails over its lexical contrastive function.
Reducing expressive variation in speech with synchronous speech
Authors: Cummins Fred
Published: February 2014

Any two utterances of the same word (or other unit) will differ. The variation arises from the summation of both linguistic and nonlinguistic factors. A major problem in studying prosody has been deciding what are the linguistic, and what are the nonlinguistic factors which collectively influence a measured quantity such as duration or pitch excursion. A substantial reduction in variability can be obtained by having two or more speakers read a text in synchrony. This task demands that they eliminate most of the nonessential prosodic variability in their speech. Speakers have little difficulty with this task, and can produce highly synchronized speech with little effort and little or no previous practice. A parallel exists with musical performance: ensemble playing is much less variable than the performance of a soloist. Synchronous speech so obtained is potentially useful for distinguishing between linguistic and nonlinguistic sources of variability. It thus may be a useful tool for the experimental phonetician, where speech relatively untainted by individual expressiveness is required. It may also be of use for applications in which a minimization of expressive variation is required. Its suitability for collecting speech to use in a database for concatenative synthesis is currently being assessed.
Sequences from number theory for physics, signal processing, and art
Authors: Schroeder Manfred R.
Published: February 2014

This work will discuss numerical sequences of potential interest to physicists, engineers, and artists. Foremost among these are the maximum-length sequences, based on the prime number 2 and larger primes, which have found wide use in physics, including acoustics, and engineering: (1) the measurement of impulse responses in concert halls, radar echoes from planets (to check the general theory of relativity) and travel times in the deep-ocean sound channel (to monitor water temperature and global warming); (2) the spatial diffusion of sound waves, coherent (laser) light, and electromagnetic waves; (3) algebraic error-correcting codes (simplex and hamming codes); (4) minimizing peak factors for radar signals, synthetic speech, and computer music; and (5) the formation of x-ray images with 2-D masks (in x-ray astronomy). Other sequences to be described include quadratic-residue sequences for the construction of wideband diffusing reflection phase gratings in one and two dimensions; the MorseThue, Fibonacci, and rabbit sequences and their musical potential; and certain self-similar sequences from number theory that engender attractive visual patterns, rhythms, and melodies.
Phase reflection diffusers design using Huffman sequences
Authors: Angus James
Published: February 2014

Phase reflection diffusers based on integer sequences are, unfortunately, limited in their frequency response. The purpose of this paper is to present an alternative form of diffusion structure using noninteger sequence based phase reflection gratings. This paper will present a new method of generating such diffusers based on Huffman sequences. The theory, design, advantages, and limitations of these structures will be discussed and simulation results of their performance will be presented. In particular, their independence from the frequency response effects typical of integer based sequences. Methods of extending and improving their performance will also be suggested. Methods of construction will also be discussed. The paper will show that it is possible to develop diffusing structures which have a better frequency performance than conventional phase reflecting structures.
Exploiting number-theoretical properties of binary M sequences for acoustical measurements
Authors: Xiang Ning , Schroeder Manfred R.
Published: February 2014

Due to their excellent number-theoretical properties, binary maximum-length sequences (M sequences) have received wide acceptance in many scientific and engineering fields. Since the introduction of M-sequence measuring technology into acoustics community in 1979 [J. Acoust. Soc. Am. 66, 497–500 (1979)] by one of the authors (MRS), advanced measurement techniques have emerged in fields such as architectural acoustics, physical acoustics, ocean acoustics, and ultrasonics. As excitation, binary M sequences carry much more signal power within a single period than signals used in the pulse-echo method. Together with its inherent cross-correlation mechanism, this technique enables high noise immunity. A fast algorithm, called a fast M-sequence transform, can be applied for performing the cross correlation. A number of noteworthy properties of binary M sequences such as shift-and-add, Zech’s logarithm, decimation, reciprocity, permutation, auto and cross correlation will be described with the emphasis of their applications in various acoustical measurement.
Development of the MLS technique at IRC/NRC, Canada
Authors: Chu Wing T.
Published: February 2014

In the early days of digital electronics, MLS (maximum-length sequence) with a very long period has been used primarily as a substitution for the conventional white noise generators employing gas discharge tubes or temperature-limited diodes. Hence, it is also called pseudorandom sequence. But MLS is in fact periodic and deterministic. When exactly one period of data is used, no ensemble averaging is required. It seems that such an application has been overlooked in the field of architectural acoustics until Schroeder published his works in the late 1970s. This potentially very useful technique was immediately recognized at IRC/NRC and a program was set up to develop the technique with special emphasis on applications to the various architectural acoustics measurements. This talk will trace our development work and present results obtained from the various applications of the technique.
Time-varying broadband interference patterns in the acoustic field during a shallow water, fixed-fixed experiment
Authors: D’Spain Gerald L. , Berger Lewis P. , Smith Jerry A. , Terrill Eric J.
Published: February 2014

During a joint experiment between the Marine Physical Laboratory and the Applied Research Lab, Penn State University in Fall, 2000, continuous-broadband signals in the 100–400 Hz band were transmitted from a moored source to a large-aperture horizontal hydrophone array on the ocean bottom in 175-m water. Spectrograms over a 24-hour period were created from the data from several array elements. These long-duration spectrograms show sinuous interference patterns formed by the regions of modal constructive interference that can be easily traced throughout the entire 24-hour period. The time dependence of the amplitude and center frequency of these individual serpentine structures are correlated with variations in environmental conditions. In particular, their frequency-meandering nature is associated both with tidally driven changes in water depth and the watch circle of the moored source. Temporal oscillations in their amplitude occur with the same periods as those of internal waves. Abrupt jumps in their frequency content occur at the same time as rapid thickening of the upper mixed layer. A simple analytical model is used to predict many of these characteristics. [Work supported by ONR, Code 321US.]
Effects of bandwidth, center frequency, and prefiltering on passive ordinary and higher order correlation detection of broadband transients
Authors: Dean Marcella E. , Ioup George E. , Ioup Juliette W. , Pflug Lisa A.
Published: February 2014

Earlier work done by the authors for passive detection of broadband signals using various functional inputs has resulted in only incremental improvements over the ordinary correlation detection of received signals. Prefiltering of the signal before input to cross-correlation, bicorrelation, and tricorrelation detectors improves detection by as much as 12 dB at a probability of detection (Pd) of 0.5 and a fixed false alarm rate of 0.001. This research is a systematic investigation using various filter widths for broadband chirp transients with bandwidths of 50, 150, and 250 Hz and center frequencies of 130, 430, and 730 Hz. To investigate detector performance, Monte Carlo simulations and hypothesis testing are done to generate ROC curves of Pd vs SNR. Results show that center frequency does not change the optimal filter width; it is solely dependent on the signal width, with decreasing filter size for narrower signals. Finally, the best detection performance is achieved with the tricorrelation detector, for which optimal filter widths vary less with input signal width than those of the optimal filters for the cross-correlation detectors. The tricorrelation detectors are about 3 dB better than the cross-correlation for each input width and center frequency. [Research supported by ONR.]
Acoustic propagation through surface ship wakes
Authors: Culver R. Lee , Di Xiao , Rapids Brian , Lutz Steven , Bradley David
Published: February 2014

To predict acoustic propagation through a ship wake, an understanding is required of the physical properties (void fraction, spatial and temporal variation of the bubble structure, oceanic ambient dynamics, for example) of the wake, as well as an acoustic propagation model capable of handling the changes in these properties. The wakes of large surface ships contain high concentrations of air bubbles of various sizes and nonuniform distributions, which give the wake decidedly inhomogeneous acoustic properties. The extant literature contains little quantitative information. Limited material has been collected and combined with a notional hypothesis regarding the random structure to produce a physical model for some of the relevant physical properties. The model has been used as a basis for propagation calculations for this complex situation. Two methods have been employed for those calculations: range-dependent, Gaussian beam ray tracing and a 2-D parabolic equation technique, the latter having previously proven useful for turbulent atmospheric conditions. The acoustic model predictions provide a clear indication of the complexity of the problem and motivation for development of a 3-D propagation model. [Work supported by ONR Code 321 (ARL Project).]
Bispectra of internal waves in shallow seas
Authors: Wang Tao , Gao Tian-Fu , Ma Li
Published: February 2014

Densely sampled thermistor chain data have been obtained from several shallow-water acoustics experiments in the Yellow Sea, East China Sea and South China Sea. The data are analyzed to study bispectra of the internal waves observed in this paper. The magnitudes, real and imaginary parts of the bispectra are presented. It is found that strong quadratic interactions occur within the power spectral peak, and also between the peak and its first three harmonics. The real and imaginary parts of the bispectra represent the contributions to the vertical and horizontal asymmetry (skewness and asymmetry) of the internal wave elevations from each frequency pair, respectively. The nonzero asymmetry values indicate the sawtoothlike waveforms. Bispectral analysis is thus a useful means for investigating nonlinear properties of shallow-water internal waves. [Work supported by NSFC.]
Moments of internal gravity waves
Authors: Wang Tao , Gao Tian-Fu , Ma Li
Published: February 2014

Observations have revealed the widespread distribution of internal waves in deep oceans, shallow seas, lakes and reservoirs. Much theoretical, numerical, laboratory and field work has studied their generation and propagation, and in particular significant progress has been made in internal solitary wave research. However, statistical properties of internal waves, especially in shallow water, are still little understood. This paper is to investigate the second-, third- and fourth-order moments of internal waves. Results of internal waves in a strong seasonal thermocline of the Yellow Sea are presented and analyzed. It is found that the skewness coefficients are nonzero and the kurtosis coefficients are greater than 3, indicating skewed waveshapes and non-Gaussian distributions of the internal wave elevations. Statistics have been widely used to describe nonbreaking shoaling sea surface waves. It is suggested that the present study on internal gravity waves could be extended to construct nonlinear models for shallow-water internal waves. [Work supported by NSFC.]
On acoustic wave field response to internal waves in shallow water for variable source position
Authors: Mu Yongke , Badiey Mohsen , Ghias Reza , Lynch James
Published: February 2014

Acoustic variability is examined using a subset of the swarm\’95 experiment data in our earlier work [J. Acoust. Soc. Am. 108, 2577 (2000)]. Acoustic signals are highly modulated both temporally and spatially due to the presence of internal waves. In addition to energy fluctuations, a large level change in transmission loss was found in the airgun data due to source position changes. The mechanism that contributes to acoustic modulations is mainly due to acoustic mode coupling induced by internal wave propagation. The acoustic modes are decomposed from the data. Mode decorrelation time is examined for different propagation tracks. Fluctuations of the modal correlation indicate an acoustic recorrelation at a longer lag time, which also indicate acoustic intensity variations due to internal waves. Source location was found to be the major factor for high-energy level variations. It is found that the airgun is depth position sensitive. The acoustic intensity and frequency variations due to source position changes are investigated in detail. A depth insensitive source (linear frequency-modulated sweep) was used for comparisons in this study. In order to understand the physics of this problem, acoustic mode shape variations and mode arrival patterns are modeled numerically for a variety of ocean environment profiles.
Minimum samples sizes required to minimize variance and bias of geoacoustic estimates of seafloor properties
Authors: Ingram Ian , Thode Aaron M. , Makris Nicholas C.
Published: February 2014

Analytic expressions for the first order bias and second order covariance of a maximum-likelihood estimate (MLE) [Naftali and Makris, J. Acoust. Soc. Am. 107, 2859 (2000)] are used to rigorously determine the sample sizes necessary for a geoacoustic MLE to become unbiased and attain the CRLB. The analysis is applied to the specific case of a narrowband deterministic signal recorded on a vertical array. The biases and variances are computed for bottom sound speed, density, and attenuation in a Pekeris waveguide, for situations where the source location is either known, or must also be estimated from the acoustic data. The case of a two-layer bottom with a sound-speed gradient is also investigated. As the beamformed signal-to-noise ratio (SNR) descends below 0 dB, the bottom sound speed and density bias can exceed 100 m/s and 1 g/cc, repsectively, and at least 100 data samples are required to attain the CRLB. An optimum source range exists for minimizing bottom speed bias, and the bias sign is strongly dependent on source depth. These formulas can provide powerful tools for the design and interpretation of geoacoustic experiments.
Complete acoustic recording of water column scatters and sea bed characteristics
Authors: Knudsen Hans Petter , Webjrn Melle , Ole Arve Misund , Egil Ona , Dag Aksnes , Hans Petter Sejrup
Published: February 2014

A new vessel for marine science in Norway has been commissioned for delivery in 2003. The 78-m long, 16.5-m wide, 6000-kW powered vessel is designed for multifunctional operation. Facilities for sampling the physical and chemical characteristics of the water column, recording and sampling plankton and fish stocks, mapping the sea bottom topography, and marine geological and geophysical research constitute the scientific framework of the vessel. To eliminate fish avoidance, the vessel will be silent according to the recommendation given in ICES CRR 209, and at night the ship can be darkened. The acoustic instruments for plankton and fish recordings, sea bottom mapping and characterization are described.
Hot topics in noise
Authors: Brooks Bennett M.
Published: February 2014

In response to increasing worldwide public concern about noise, new methods and means for assessing and controlling noise have been developed. Outdoors, advancements have been made in understanding the role that soundscapes play in the quality of life in our communities, which range from urban to rural environments. Recent efforts have been devoted to quantifying and preserving the resource of natural quiet in US National Parks. The impact of theme parks and amphitheaters on their host communities is an active area of research. International development of environmental noise policy is producing significant action. Indoors, new investigations on room noise descriptors are advancing that area of noise practice. The development of standards for classroom acoustics, including practical limits on noise, has the potential to improve the educational experience for all children. Product design research for sound quality will reduce perceived noise levels, and also make the resulting sound more pleasant. Important recent findings on occupational noise effects include new criteria for noise exposure, and the real-world effectiveness of hearing protectors. For many people, acoustics is chiefly represented by noise. These advances in the practical application of acoustics promise to contribute to a more civilized and hospitable society.
An investigation of research trends in acoustics from 1970 to 1999
Authors: Pestorius Frederick M. , Viator John A.
Published: February 2014

Text data mining is a burgeoning field in which new information is extracted from existing text databases. Computational methods are used to compare relationships between database elements to yield new information about the existing data. Text data mining software was used to determine research trends in acoustics for the years 1970, 1980, 1990, and 1999. Trends were indicated by the number of published articles in the categories of acoustics using the Journal of the Acoustical Society of America (JASA) as the article source. Research was classified using a method based on the Physics and Astronomy Classification Scheme (
Analysis and resynthesis of the steady state portion of acoustic tones
Authors: Jurek Josef
Published: February 2014

Variations in amplitude and frequency over time that exist in tones produced by acoustic instruments are often difficult to capture when attempting to resynthesize such tones. In the present study, to derive a successful solution to this problem and to further our understanding of such spectral variations over time, the amplitude envelopes of each overtone during the steady state portion of six musical tones were modeled as a spectra and used for resynthesis. A number of techniques for minimizing analysis artifacts in creating these envelope spectra are explored and evaluated as well as some techniques for manipulation of these spectra before resynthesis.
The behavioral ecology of animal vocal communication: An information theoretic approach
Authors: McCowan Brenda , Doyle Laurance , Hanser Sean
Published: February 2014

Innovative approaches for analyzing animal vocal communication are needed to investigate the behavioral ecology underlying the composition and structure of animal vocal communication systems. This approach will require a quantitative comparative analysis of animal vocalizations from different populations and species. To date, few studies have quantitatively examined vocal and repertoire structure in relationship to social or ecological strategies in populations of mammalian species. This lack of information has hindered our understanding of the behavioral ecology and evolution of mammalian vocal communication. We will present and discuss quantitative comparative measures from information theory that provide important insights into the ecological and social processes that shape the structure and organization of vocal repertoires. Information theory provides a powerful and efficacious approach because it links the physical, biological, and social properties of the environment to the structure of communication systems on multiple analytical and conceptual levels. Using two phylogenetically unrelated species as examples (i.e., bottlenose dolphins, squirrel monkeys), we will consider each level of communication, from the acoustic structure within call types to the complexity of call sequences, for a comprehensive approach toward animal vocal communication and its relationship to human language systems. [Work supported by NIH, Marine World Foundation, and SETI Institute.]
Information entropy—interpretation and estimation
Authors: Suzuki Ryuji
Published: February 2014

Information theory originated in a series of papers by Shannon in 1948, where he sketched an important theoretical framework for characterizing information sources and communication channels. Subsequently, information theory has primarily studied theoretical problems based on known source and channel properties. Although Shannon’s theory was in spirit applicable to a wider class of problems, information theory has paid less attention to analysis problems, where an observed signal is accessible to the researcher but the underlying true mechanism is unknown, e.g., statistical estimation and hypothesis testing problems. This paper reviews the properties of information entropy and common techniques for estimating and interpreting it. The performance and pitfalls of common entropy estimators are illustrated with examples. Specifically, the naive technique of substituting relative frequencies or empirical distribution into the definition of entropy is shown to produce inaccurate estimates. An alternative technique for analyzing observed data, the sliding window match length estimator, is relatively simple to implement, can be intuitively understood, and is mathematically well supported.
A comparison of two information theory approaches to animal communication systems
Authors: Doyle Laurance R. , Jenkins Jon M. , Hanser Sean F. , McCowan Brenda
Published: February 2014

Information theory has been used to analyze and explore animal communication systems using two different approaches. The first approach—which is the original application outlined by Shannon and Weaver (1949)—considers the temporal distribution (i.e., probabilities of occurrence) of the components of a communication system to quantify the diversity and complexity of a system’s (repertoires) organization. This quantification of the communication complexity is based on the information content, not just at the repertoire level, but also at the sequential (i.e., Markovian) organizational levels of the signals constituting the communication system. The second approach, which has been much more widely applied, with mixed results over several decades, considers a communication system’s ability to essentially ‘‘encode’’ signaling between individuals in order to measure how much information has been ‘‘transmitted.’’ We will outline and contrast these two approaches, pointing out that until the communication complexity of the entire signaling system is quantified, there is little hope of correctly interpreting information exchange between individuals using that system of communication [C. Shannon and W. Weaver, The Mathematical Theory of Communication (University of Illinois Press, 1949)].
Assessment of ecosystem biodiversity by acoustic diversity indices
Authors: Gage Stuart H. , Napoletano Brian M. , Cooper Michael C.
Published: February 2014

Assessment of ecosystem biodiversity by measurement of acoustic diversity was explored [B. L. Krause, Explorers J., Winter, 156–160 (1993)]. Specific acoustic indices (e.g., based on frequency spectrum) were developed and correlated with standard diversity indices (e.g., standard species abundance indices). Necessary technological infrastructures and analytic processes to measure acoustic dynamics of ecological biodiversity were explored. An automated web-based infrastructure capable of capturing, processing, and relaying real-time field measurements from multiple ecosystems to desktop and home computers was developed, tested, and implemented. Key infrastructure components were remote field instrumentation, remote computer processing, wireless digital relay instrumentation, Internet server, and automation, relational database, and website software. A dynamic digital library of ecological acoustic samples, correlated ecosystem attributes, and acoustic analysis methodologies was established. Library resources, including digital sound files captured from ecosystems, were made available to researchers and the public over the Internet [N. Metzger and M. Blumenthal, Realizing Info. Future, NAP, 113–119 (1994)]. Indices of acoustic ecosystem diversity were refined through application on existing digital ecosystem sound recordings and digital sounds captured from multiple ecosystems. The performance of these indices was compared to standard biodiversity indices applied to the same ecosystems.
Thermal damage analyses of human skin cells by scanning acoustic and atomic force microscopies
Authors: Miyasaka Chiaki , Du Jikai , Tittmann Bernhard R.
Published: February 2014

The acoustic microscope (SAM) is a well-known tool for imaging biological cells with high resolution. Here images of living human skin cells (HaCat) in a culture liquid (dMEM+10% FCS) are presented. The cells were grown onto square glass plates (15.0 mm × 15.0 mm), which were mounted on the bottom of a plastic well, which in turn was placed on the temperature-controlled stage of our scanning acoustic microscope (Olympus UH-3). Images were obtained at a frequency of 600 MHz as the temperature was increased from 37.5°C to the threshhold temperature for cell death (atoptosis). The temperature was increased 1°C every 3 min. The acoustic beam from a high numerical-aperture (NA) lens was focused onto the cells by monitoring the absorption of the reflected waves. By using image processing (DSP), features could be identified, such as change in thickness, cell rounding, lateral shrinkage, and atoptosis. The shapes and dimensions were confirmed by Atomic Force Microscopy (AFM). The SAM and AFM are thus effective tools for characterization of living cells.
A framework for annotating animal bioacoustic data
Authors: Maeda Kazuaki , Bird Steven
Published: February 2014

Annotation graphs (AGs) provide an efficient and expressive data model for linguistic annotations of time–series data [Bird and Liberman, 2001]. The term annotation here refers to the association of structured symbolic information with an extent of signal data. This paper demonstrates that AGs also provide an excellent framework for annotating time–series animal bioacoustic data. The AG model has several desirable properties for annotating animal bioacoustic signals. Partial or incomplete annotations can be represented naturally. Hierarchical structures, such as internal structures of animal communicative signals, can be stored and manipulated effectively. The model permits efficient query using the relational database technology. The spreadsheet-like editor component described in the paper provides an intuitive user interface for creating annotations of bioacoustic signals, such as monkey vocalizations, as AG data. The paper describes the tool used for annotating the vocalization of vervet monkeys, and the preliminary findings of the project are presented. Finally, the paper lays out a complete infrastructure for supporting the rapid development of annotation tools for animal bioacoustic data [S. Bird and M. Liberman, ‘‘A Formal Framework for Linguistic Annotation,’’ Speech Commun. 33, 23–60 (2001)].
Multiple scattering in a reflecting cavity: Application to fish counting in a tank
Authors: Roux Philippe , De Rosny Julien
Published: February 2014

Classical fisheries acoustics techniques are useless in the presence of multiple scattering or reflecting boundaries. A general technique is developed that provides the number and the scattering strength of fish in motion placed inside a highly reflecting cavity. This approach is based on multiple scattering theory. The idea is to measure the average effect of the fish on the acoustic echoes of the cavity interfaces. This leads to the measure of the scattering mean free path, a typical length that characterizes the scattering strength of the fish school. Numerical results are shown to agree with a simple theoretical analysis. Experiments are performed with fish in a tank at two different scales: ultrasonic frequency (400 kHz) in a 1.4-l beaker with 1-cm-long fish as well as fisheries acoustics frequency (12.8 kHz) in a 30-m3 tank with 35-cm-long fish. These results have interesting applications to fish target strength measurement and fish counting in aquaculture.
Overview of ultrasound-induced lung hemorrhage, and a comment about the mechanical index
Authors: O’Brien William D. , Frizzell Leon A. , Simpson Douglas G. , Zachary James F.
Published: February 2014

It has been well documented that ultrasound-induced lung hemorrhage can occur in mice, rats, rabbits, pigs, and monkeys. Our own experimental studies have focused on mice, rats, and pigs as animal models. The characteristics of the lesions produced in mice, rats and pigs were similar to those described in studies by our research group and others, suggesting a common pathogenesis for the initiation and propagation of the lesions at the macroscopic and microscopic levels. We demonstrated that lung hemorrhage in mice was not caused by inertial cavitation. Threshold estimates and superthreshold behaviors were investigated as a function of species (adult mice and rats) and ultrasound frequency (2.8 and 5.6 MHz), and showed that mice and rats were similar in sensitivity to lung damage with similar and frequency-independent threshold estimates. A 3×5 factoral-designed study (3 exposure durations and 5 pulse repetition frequencies) at the same superthreshold exposure level in adult mice and rats showed that pulse repetition frequency and exposure duration both affect the percentage of animals with lesions. The research reported in these studies and others we have done proves increasing evidence that the mechanical index is inconsistent with observed findings. [Work supported by NIH Grant No. HL58218.]
Diagnostic ultrasound with contrast agent induces membrane damage in monolayer cells in vitro
Authors: Miller Douglas , Quddus Jawaid
Published: February 2014

Interaction of diagnostic ultrasound with contrast agent gas bodies can induce membrane damage in monolayer cells. Epidermoid (A431) and phagocytic (RAW-264.7) cells were grown on 5 micron thick Mylar sheets, which formed the upper windows for 1 mm deep exposure chambers. For exposure, a 3.5 MHz transducer from an acoustic imaging (model 5200B) scanner in spectral Doppler mode was aimed upward at the chamber, 7 cm away, in a 37 °C water bath. Damage was indicated by sonoporation (uptake of large fluorescent molecules) and cell lysis (trypan blue staining). Apparent thresholds for membrane damage with 1% optison and 1 min exposure after 30 s rise and warmup time were about 0.12 MPa for both cells lines. The gas bodies tend to stick to the phagocytic cells, but not to epidermoid cells. When incubated with 5% agent for 15 min and then rinsed to remove unattached gas bodies before exposure, the RAW cells retained the 0.12 MPa threshold, but effects were greatly decreased for epidermoid cells. These results indicate relatively low thresholds for membrane damage, and suggest a potential for targeting of phagocytic cells for membrane damage by diagnostic ultrasound with contrast agents. [Work supported by NIH Grant No. CA42947.]
Standardizing the estimation of in situ ultrasound exposure in beams with strong nonlinearity
Authors: Duck Francis
Published: February 2014

This paper will discuss alternative approaches to the problem of predicting in situ exposure from acoustic measurements made in water. Ultrasonic pulses from medical diagnostic scanners commonly exceed sigma=1 in the focal region in water, and the associated amplitude-dependant loss of energy from the beam causes in situ exposure estimates from linear assumptions to be in error. Alternative approaches have been and will be explored in order to establish robust methods of universal applicability. One approach requiring low amplitude operation followed by linear scaling shows promise. Such an approach may overestimate in situ exposure, making it acceptable as a means for safety management. Standard techniques will need to be established to set upper thresholds during measurement. These may place a limit on the acoustic pressure at the source or at the focus, or on a derived quantity such as sigma(m). Alternatively a limit may be placed on the allowed harmonic level at the measurement point. Other approaches will be reviewed, including those using tissue equivalent media, and those computing in situ exposure directly from high-amplitude free-field measurements in water. It is noted that procedures appropriate for manufacturing standards may not be appropriate for individual patient dosimetry.
Role of pulse repetition frequency and exposure duration in mice and rats with lung hemorrhage induced by exposure to superthreshold pulsed ultrasound
Authors: O’Brien William D. , Frizzell Leon A. , Zachary James F.
Published: February 2014

Superthreshold behavior for ultrasound-induced lung hemorrhage was investigated in adult mice and rats at an ultrasound center frequency of 2.8 MHz to assess the role of pulse repetition frequency (PRF) and exposure duration (ED). One hundred fifty 6-to-7-week-old mice and 150 10-to-11-week-old rats were each divided into 15 exposure groups (10 animals per group) for a 3-by-5 factorial design (3 EDs: 5, 10, 20 s; 5 PRFs: 25, 50, 100, 250, 500 Hz). The in situ (at the pleural surface) peak rarefactional pressure of 12.3 MPa [MIs of 6.3 (mice) and 7.1 (rats)] and the pulse duration of 1.42 μs were the same for all ultrasonically exposed animals. The lesion depth and surface area were measured for each animal as well as the percentage of animals with lesions per group. The proportion of lesions in both species was related statistically to PRF and ED, with the exception that PRF in rats was not quite significant; the PRF×ED interaction (number of pulses) for lesion production was not significant for either species. The PRF, but not ED, significantly affected lesion depth in both species. Both PRF and ED significantly affected lesion surface area in mice. [Work supported by NIH Grant No. HL58218.]
Modern magnetostrictive materials
Authors: Restorff James B. , Wun-Fogle Marilyn , Clark Arthur E.
Published: February 2014

Two classes of magnetostrictive materials are emerging which can strongly impact magnetomechanical transduction and high-stress antivibration systems. One class utilizes highly magnetostrictive rare earths with anisotropic 4f electron shells. The second class is based upon α−Fe, with substitutions of nonmagnetic Ga and Al for Fe. The first class contains three distinct types of materials: (a) hexagonal Tb1−xDyx alloys, (b) cubic CsCl type Tb1−xDyxZn alloys, and (c) cubic Laves phase Terfenol alloys. While the first two types produce extraordinarily high magnetostrictions only at cryogenic temperatures, Terfenol alloys exhibit large magnetostrictions (>1000 ppm) at 200°C and above. This paper will focus on recent measurements on low-hysteresis Terfenol-DH alloys taken between −40°C–+80°C. The new class of promising high-strength, low-cost, Fe-based alloys will also be introduced. Here the emphasis is on the development of a ductile, high tensile-strength material with high strains (>300 ppm ), high relative permeabilities (>100), and low excitation fields (<300 Oe) under high loads. Magnetostriction, magnetization and elastic constant measurements as a function of stress and magnetic field will be presented. Values of piezomagnetic constants and coupling factors, calculated from these measurements, will be included. [Work supported by ONR.]
TERFENOL-D manufacturing practices and their design impacts
Authors: Snodgrass Jon
Published: February 2014

The manufacture of TERFENOL-D has a substantial impact on the possible designs of acoustic transducers. As with all transducer materials, a better understanding of the manufacturing process can enable the designer to avoid various pitfalls that impact not only performance but cost as well. This presentation will in essence be a primer on the manufacture of giant magnetostrictive materials. Substantial changes have taken place since the invention of the materials. The history of these changes and the subsequent design limitations will be discussed. The current state-of-the-art of TERFENOL-D production will be presented, and key features that have design impacts will be highlighted, especially where the design possibilities have been increased through the refinement of the production techniques. This will focus primarily on the crystal growth of TERFENOL-D but will also include details of characterizing the material and the machining of the driver to its final configuration, which has a substantial impact on cost. Current efforts to further refine and improve these processes will also be presented to indicate the future capabilities that can be expected.
Large strain particulate magnetostrictive composites
Authors: McKnight Geoff , Carman Greg P.
Published: February 2014

In this presentation we will describe recent progress on manufacturing particulate magnetostrictive composites that produce large strains (>1600 microstrain). The composites are manufactured by combining Terfenol-D particulate with a polymer resin in the presence of a magnetic field. The field aligns the particulates into continuous chains similar to continuous fiber composites. Magnetostrictive particulate composite research has been conducted by a variety of research institutions during the last decade. Most studies report values for saturation strain on the order of 800 microstrain, however, UCLA found that by combining selected particles the saturation strain increases to 1200 microstrain. While this represents an improvement, these strain levels (1200) were still below those reported for the monolithic material (i.e., 1800 microstrain). During the last year UCLA discovered a manufacturing technique that increases the saturation strains to values comparable with the monolithic material (1700 microstrain). A representative figure comparing the response of the monolithic material to a 20% volume fraction particulate composite is provided in the figure in this paper. Note that the strain outputs from the composite are similar to those from the monolithic material. Both these large strains and the large bandwidths provided by the particulate composites suggest opportunities exist for use in high power sonar devices.
Biased resonance measurements as predictors of large-signal performance of PMN-PT
Authors: McLaughlin Elizabeth , Robinson Harold
Published: February 2014

The large-signal performance of electrostrictive materials, such as lead magnesium niobate-lead titanate, is of critical importance to sonar and actuator designers. However, obtaining these large signal parameters properly, particularly under compressive prestress, is expensive and time consuming. The complexity of these measurements precludes them as a method for quickly and easily screening materials. Traditionally, resonance measurements, which otherwise are relatively simple to perform, have been used, but they suffer from the drawback that the material parameters obtained are at the incorrect frequency and under no prestress. Furthermore, the significance of the results of resonance measurements for nonlinear materials is unclear. It has recently been suggested [Hom and Shankar, IEEE Trans. Ultrason. Ferroelectr. Freq. Control UFFC-46, p. 1422, 1999] that dc biased resonance measurements on electrostrictive ceramics would be an accurate predictor of the coupling factor and optimum bias point. Here, dc biased resonance measurements on several formulations, with varying dielectric maximum temperatures, are analyzed to determine which composition has the highest predicted coupling factor. This prediction is compared with large signal quasistatic measurements conducted on NAVSEAs SDECS (stress-dependent electromechanical characterization system). The predictive ability of the resonance measurements is analyzed as a function of temperature. [Work supported by ONR.]
State of Illinois noise regulations in 2001
Authors: Zak Greg
Published: February 2014

Since 1973, the State of Illinois has had noise regulations. Active enforcement of these regulations has been ongoing in different forms depending on what resources are available to accomplish this end. Prior to 1981, Illinois had the funding to actively investigate noise complaints and refer those cases that had merit to the Attorney General’s office for prosecution. Loss of funding for both state and federal noise programs resulted in greatly reduced enforcement after 1981. Illinois addressed this situation by making best use of remaining resources in order to initiate innovative noise limit enforcement activities. The result has been more actual noise control from the 1990s to 2001 than was obtained prior to the 1981 programmatic cuts.
Cook County noise regulation
Authors: DeRose Louis
Published: February 2014

Cook County is an urban county consisting of over 5-million people in a 700-square mile area which includes the city of Chicago. Some 130 villages and municipalities in the area outside the city of Chicago provide a governing and zoning mix that places commercial and industrial entities in close proximity to residential communities. In addition, a complex system of roadways and expressways impacts on nearly all citizens. Through enacting Article 9, Noise and Vibration Control, the Cook County Board of Commissioners has recoginzed the potential for jurisdictional disputes and conflicts and has charged the Department of Environmental Control with the responsibility of enforcing uniform property-line noise standards to ensure the quality of life for our citizens. The Department is often the only source of relief for problems of this nature. However, the Noise Ordinance is under increased scrutiny and confrontation from local governments due to jurisdictional conflicts and is in need of review. This presentation will discuss the status of this ordinance, the methods of enforcement and the status for review and update.
James Clerk Maxwell and the propagation of sound in gases
Authors: Marston Philip L.
Published: February 2014

In the published abstract of his original presentation of statistical kinetic theory, James Clerk Maxwell noted that, ‘‘The author intends to apply his mathematical methods to the explanation on this hypothesis of the propagation of sound...,’’ [British Association for the Advancement of Sciences (1859)]. Although it appears that he did not consider the propagation of sound in his subsequent publications on the kinetic theory of gases, Maxwell eventually examined the relationship between the speed of sound and the rms particle velocity in gases. His result for monatomic gases appears in a postscript of a paper communicated by Maxwell [S. T. Preston, Philos. Mag. 3, 441–453 (1877)]. In Preston’s publication, and in Preston’s 1876 letter to Maxwell, the related early work of J. J. Waterston is noted. While the postscript has been previously noted [see, e.g., M. Greenspan, Phys. Acoust. 2 A, 1–45 (1965)], other aspects of Maxwell’s acoustical activities are less obvious. These include Maxwell’s referee reports on manuscripts. The manuscripts by Stokes (1868), Rankine (1870), and Rayleigh (1871) were published and becamse acoustical classics. Maxwell also suggested the title to Rayleigh’s, ‘‘The Theory of Sound,’’ in an 1873 letter to Rayleigh.
On radiation of sound from open end of an irregular wedge-shaped waveguide
Authors: Matsipura Vladimir T. , Grinchenko Victor T.
Published: February 2014

The characteristics of sound field radiated from the open end of a wedge-shaped waveguide are studied. A characteristic feature of the waveguide geometry is that the edges of nonparallel half-planes are arranged on different distances from the wedge apex. The additional elongation of the wall is considered as a screen and is an important element in the mechanism of control of the near- and far-field characteristics. To solve the corresponding boundary problem an analytical method has been developed. The central idea of the analytical method and the possibility of one to solve other boundary problems are discussed. The radiated sound field is produced by an incident mode in waveguide. Qualitative data about space structure and energy characteristic of the radiated field are presented. The data about change of the sound pattern when the parameters of the waveguide are changed illustrate the complex structure of the radiated sound field and strong dependence of one on the structure of a normal wave carrying the energy to the edge of the waveguide. Qualitative description of the far-field structure is complemented by data about the concentration factor of sound energy and distribution of energy between transmitted and reflected waves.