bluuebunny/crossref_metadata_2025 huggingface dataset:
Mean acoustic field in long-range ocean acoustic propagation experiment (LOAPEX)
Authors: Andrew Rex K. , Henyey Frank S. , Mercer James A. , Howe Bruce M. , Worcester Peter F. , Dzieciuch Matthew A.
Published: October 2013

We extract the low-frequency (70-Hz) mean acoustic pressure field, and the mean acoustic field up to time shifts, from the LOAPEX receptions on the vertical line arrays, for transmissions at various ranges. Means are taken over time intervals of order a day. Source and receiver motion is removed from the data, and possibly tides and other slow phenomena. The experimental results are compared to predictions from theoretical calculations assuming scattering by internal waves. The theoretical calculations make the Markov approximation that the sound-speed fluctuation correlations can be replaced by an operator at a single range. The calculations use modes rather than rays, because of the very low frequency, thus differing from the version of the Markov approximation that assumes delta-correlated sound-speed fluctuations.
An online virtual acoustic guitar laboratory
Authors: Lee Nelson , Smith Julius O.
Published: October 2013

We present a ‘‘virtual acoustic guitar laboratory’’ in which students can bring in their own acoustic guitars, record several notes, and follow a step-by-step procedure to create their own real-time computational model, suitable for use in a synth plugin in an electronic music studio. The guitar synthesis model is based on the commuted waveguide synthesis technique (http://ccrma.stanford.edu/∼jos/cs.html). Online laboratory materials are presently available at (http://ccrma.stanford.edu/∼jos), the project website (http://ccrma.stanford.edu/realsimple/), and are also being ported to Connexions (http://www.cnx.org/), an online repository of educational materials freely distributable under a Creative Commons license. Connexion’s ‘‘modules’’ and ‘‘courses’’ (which are simply module sequences) are readily and freely accessible and modifiable to allow instructors to adapt the materials as appropriate for their own classroom needs. The online lab materials contain Web pointers to relevant portions of online textbooks covering theoretical aspects of the analysis and synthesis methods used, thereby offering the student a demand-driven deeper understanding within a motivating context. [This work was supported by the Wallenberg Global Learning Network.]
An acoustic functional grammar of English intonation
Authors: Hatfield Hunter B.
Published: October 2013

There has been a resurgence in recent years of linguistic models that directly embed exact physical and acoustic data right into the formalism. This work attempts to show that many aspects of speech perception and production can only be understood when the acoustic input is fully considered. In the case of speech perception, if there are abstractions, they are abstractions over acoustic input, not based on a priori phonological categories. The current paper extends this work into English intonation. The functional phonology of Paul Boersma, which incorporates exact frequency values into an optimality theoretic perception grammar, is extended to explain several basic facts about English intonation, including the derivation of categorical high and low tones from the acoustic signal, the relation of tones to hierarchically adjacent tones, and the affectual aspects of classically paralinguistic intonation. The primary advantage of this approach is that it allows a single model to handle both linguistic and paralinguistic intonation structure, a merger which is only possible due to the use of physical acoustic data in the model.
Does English have accent domains?
Authors: Shilman Molly
Published: October 2013

In ToBI systems, there are languages in which a pitch accent is the head of a particular level of phrase (accentual phrase) (e.g., French, Japanese), and those in which pitch accents are largely independent of phrasing (e.g., English, German). However, some theories of syntax-prosody mapping, such as Truckenbrodt’s (1999), assume that a pitch accent is always the head of some prosodic domain. Such theories thus predict that every language with pitch accents should have a prosodic unit that is the domain of pitch accent. Previous work suggests that prosodic boundaries tend to be marked by several types of phonetic cues, including final lengthening (Wightman et al., 1992; Jun, 2005). This study uses a controlled production experiment to determine whether there are accent domains in English: speakers produce near-minimal triplets in which the syntactic relations between words are changed by context but the segmental string, location of word boundaries, and location of the single pitch accent within the target phrase all remain fixed. Productions are then compared for final lengthening at the location of target boundaries. Preliminary results suggest that there is an accent domain in English.
Production characteristics of accent in four dialects of Nahuatl
Authors: Guion Susan G. , Amith Jonathan D. , Doty Christopher , Shport Irina A.
Published: October 2013

Most descriptions of Nahuatl (Uto-Aztecan, Mexico) describe regular penultimate accent, although production characteristics are unstudied. Recently, however, dialects from Guerrero state have been described with pitch-accent from historical coda breathy /h/ in nonfinal position [Guion and Amith, J. Acoust. Soc. Am. 117, S2490 (2005)]. In the current study, the acoustic correlates of this new pitch-accent, as well as penultimate accent, are investigated. Speakers (n=6) from four dialects–two with innovated pitch-accent and two with only penultimate accent–were recorded. The production characteristics of fundamental frequency (F0), duration, and voice quality, as indexed by the difference between the first two harmonics (H1-H2), were investigated. Innovated pitch-accent was found to be cued solely by F0. Penultimate accent varied in its production by dialect. In dialects with only penultimate accent, production exhibited characteristics typical of stress-accent: Accented syllables had higher F0, longer durations, and more vocal effort (smaller H1-H2 differences) than unaccented syllables. Dialects with innovated pitch-accent had less stresslike penultimate accents, being cued primarily by F0, or with a relatively small durational difference, but no voice quality difference. This indicates that the innovation of a pitch-accent has changed the formerly stresslike penultimate accent into a more pitch-type accent.
The voices of anger and disgust: Acoustic correlates in three languages
Authors: Pell Marc D. , Alasseri Areej , Kotz Sonja A. , Paulmann Silke
Published: October 2013

Anger and disgust are believed to represent discrete human emotions with unique vocal signatures in spoken language. However, few investigations describe the acoustic dimensions of these vocal expressions, and some researchers have questioned whether disgust is robustly encoded in the vocal channel. This study sought to isolate acoustic parameters that differentiate utterances identified as sounding angry versus disgusted by listeners based on evidence from three separate languages: English, German, and Arabic. Two male and two female speakers of each language produced a list of pseudo-sentences (e.g., Suh fector egzullin tuh boshent) to convey a set of seven different emotions. The recordings were later judged by a group of native listeners to determine what emotional meaning was perceived from the prosodic features of each pseudo-utterance. Individual sentences identified systematically as conveying either anger or disgust (greater than 3× chance target recognition) were then analyzed acoustically for various parameters of fundamental frequency, amplitude, and duration. Analyses compared which acoustic parameter(s) were dominant for identifying anger versus disgust in each language, and whether these patterns appeared to vary across languages, with implications for understanding the specificity and universality of these emotion expressions in the vocal channel.
Development of the fast measurement system for the listener’s own head-related impulse responses
Authors: Fukudome Kimitoshi , Tashiro Yusuke , Takenouchi Kazuki , Samejima Toshiya , Ono Naoki
Published: October 2013

Three-dimensional (3-D) spacial sound reproduction through headphones or earphones is best realized for subjects by the use of their own head-related impulse responses (HRIRs). Although HRIR measurements are so extremely time consuming, better externalized HRIRs for subjects must be collected in order to develop future 3-D applications. The fast measurement system for the listener’s own HRIRs was constructed based on the continuous measurement method with a subject sitting on a servo-swiveled chair (SSC), and together with a loud speaker elevation arm controlled by a stepping motor. It can greatly reduce the subject burden in HRIR measurements. HRIRs for all azimuthal directions at 29 elevations can be measured in 1 h, constituting a reduction by a factor of 3 of the amount of time required as compared to systems composed of an SSC and a conventional manual elevation system. In the presentation, principles of the fast measurement system and the specifications of the loud speaker elevation arm are described. Performance evaluations are presented in terms of the measurement accuracies by the signal-to-deviation ratio and the spectral distortion, and further the reproducibility in repetitive measurements. [Work supported by the specific project research in the Faculty of Design, 2005.]
Multichannel high sampling rate 1-bit audio with a high definition video recorder system
Authors: Fujimori Jun-ichi , Oikawa Yasuhiro , Yamasaki Yoshio
Published: October 2013

Ideally, as much audio, video, and metadata information as possible should be acquired to produce archives using the most advanced technology available at the time so that maximum information can be inherited. On the other hand, it is not easy to develop both audio technology and video technology simultaneously or even to integrate them. For example, because we specifically examine audio technology, it is desirable to use video products in the market to achieve the goal. In this sense, we propose the use of IEEE1394 equipment and synchronize their components for integration. We developed a high sampling rate 1-bit audio AD/DA converter that is equipped with IEEE1394 and recording and playback software running on Linux. The software can synchronize a 1-bit audio stream using MPEG-TS of HD video to extend its audio quality using IEEE1394 isochronous streaming with 125-Es resolution. This integration of audio and video is achieved without modifying existing video products. This paper describes the system and the 1-bit audio AD/DA converter (5.6 MHz sampling 8ch in 8ch out or 4.8 MHz sampling 16ch in 16ch out).
Frame virtual mass for unconsolidated granular media with slippage
Authors: Chotiros Nicholas P. , Isakson Marcia J.
Published: October 2013

A model of the grain contact physics in the presence of a propagating wave is extended to included losses due to slippage. Mechanical coupling between grains in a randomly packed unconsolidated granular medium is inherently stochastic. Grain-to-grain contact asymmetry leads to coupling of kinetic energy into orthogonal linear and rotational motion at the grain level, and partitioning of the energy. The result is an increase in inertia, which may be treated as an additional or virtual mass term for both shear and compressional waves. The virtual mass term can be evaluated, given the scintillation index of the compressional and shear contact stiffness, Poisson’s ratio, and the average number of contact points at each grain. The effect of slippage at the grain-to-grain contact is examined. [Work supported by Office of Naval Research, Ocean Acoustics.]
Frequency dependences of absorption and scattering components of attenuation for water-saturated sands
Authors: Ohkawa Keiichi
Published: October 2013

Frequency dependences of attenuation of sound waves in water-saturated marine sands are discussed. Measured attenuation includes a scattering component, and this makes it difficult to understand the frequency dependences of attenuation. By removing the scattering component from the measured attenuation, the Kramers-Kronig (K-K) relationship gives the correct sound speed dispersion. Consequently, the intrinsic attenuation extracted from the data collected during SAX99 experiments follows the Biot theory for overall frequencies. This suggests that the attenuation coefficient of sound waves for water-saturated sands is not linear in f. The sound speeds recalculated via the K-K relationship are also in excellent agreement with the Biot theory at high frequencies.
Frequency dependence of sound speed and attenuation in marine sediments
Authors: Carey William M. , Zhou Ji-Xun , Pierce Allan D.
Published: October 2013

Zhou and Zhang [J. Acoust. Soc. Am. (2005) (2006)] have reviewed diverse data for propagation in sandy sediments. Attenuation for frequencies below 1 kHz corresponds roughly to α=0.34(f/fo)2 dB/m with the reference frequency being 1 kHz. The best-fit exponent is slightly less than 2. Their review of results for frequencies above 10 kHz suggests a substantially different frequency dependence. They considered two explicit models, the Biot model as parametrized and extended by Stoll and the BICSQS model of Chotiros and Isakson [J. Acoust. Soc. Am. (2004)]. In either case the fit of parameters to match sound speed dispersion resulted in an unsatisfactory fit of attenuation versus frequency, and conversely. The present paper reexamines this and contends that, while Biot’s formulation is intrinsically correct at low frequencies, Stoll’s parametrization is noncausal: Chotiros’ model more nearly captures the correct physics in that it is intrinsically causal and includes relaxation processes. A considered extension is to include a continuous smear of relaxation processes (rather than just two) within the basic context of the original Biot model. This is shown to be wholly consistent with Kramers-Kronig relations and to have sufficient flexibility to fit the overall data set.
Manfred R. Schroeder’s life in acoustics: Phases, reflections, and other contributions of a ‘‘perfect number.’’
Authors: Kollmeier Birger
Published: October 2013

Number theory such as the rules to compose a perfect number (which is the sum of all its divisors, e.g., 6, 28, 496, 8128) constitutes only a small part of the many fields of research Manfred R. Schroeder mastered in his scientific life. After finishing his Ph.D. with Erwin Meyer in Goettingen in 1954, Schroeder joined Bell Labs where he eventually became director of acoustics and mechanics research. In 1969 he was also appointed professor of physics and director of the Drittes Physikalisches Institut in Goettingen. He contributed to many seminal publications and inventions in the areas of room acoustics, speech coding, physiological and psychological acoustics, and computer graphics. The Schroeder phases describe the quadratic initial phase relation of the harmonics in a tone complex to produce a maximum flat (speech) waveform. The Schroeder diffusors are reflection gratings based on his number theoretic considerations that suppress the specular reflections while distributing scattered sound into all different directions. The current talk will give an overview of Manfred Schroeder’s life in acoustics and his various contributions, including some stories about his unique character. A special focus will be placed on the Schroeder phases and their current use in hearing research.
Personal reflections on 20 years of research with Manfred R. Schroeder: From concert hall acoustics to code-excited linear prediction
Authors: Atal Bishnu S.
Published: October 2013

I joined Bell Laboratories, Murray Hill in 1961. Bell Labs then had an excellent environment for challenging researchers to find creative solutions to difficult problems in telecommunication. Coming from India, I was fortunate to have Manfred as my mentor. He and I collaborated on many interesting problems. Stereo sound systems in those days kept the sound confined between two speakers, and we wondered why we could not spread the sound beyond the speakers. We invented a system for creating signals at the human ears that removed this limitation, producing the beginning of surround sound. Vocoders could not synthesize natural-sounding speech, and Manfred always felt that the speech synthesis models used in vocoders were too rigid and inflexible. This kind of thinking led us to the path of adaptive predictive coding and we presented a paper on this topic at the first IEEE meeting on speech communication in Boston in 1967. We continued working together producing better and better speech quality on predictive coders. Our research led to the approach of code-excited linear prediction, which forms the basis of world-wide digital cellular standards.
Schroeder’s phase in psychoacoustics
Authors: Kohlrausch Armin
Published: October 2013

I want to address Manfred Schroeder’s contributions to psychoacoustics with a special emphasis on the period 1980 to 1990, when I worked with him at the Third Physical Institute in Goettingen. Among the psychoacoustic topics Schroeder worked on were binaural hearing, often in relation to room acoustics and stereophony, and monaural phase perception. The latter topic was first addressed in an ASA conference abstract from 1959, in which Schroeder emphasized the role of the signal’s peak factor for the perceived timbre. This theme was taken up in the famous mathematical paper in 1970, in which Schroeder demonstrated that a quadratic relation between frequency and phase in a (flat-spectrum) harmonic complex allows one to synthesize a periodic signal with a flat temporal envelope and a quasilinear frequency modulation. Quite accidentically, it was found out in Bennett Smith’s master thesis in 1984 that under specific circumstances, the input phase of the stimulus and the phase characteristic of a fixed point on the basilar membrane can nearly compensate each other. This interpretation, published in 1986 in J. Acoust. Soc. Am. with Schroeder as senior author, initiated a great number of perceptual and physiological studies on the phase characteristics of the inner ear.
Sequences and their consequences
Authors: Vorlaender Michael
Published: October 2013

Number theory is an inspiration for application in science and engineering. In acoustics, correlation sequences for measurement signals and for diffusors became famous, mainly due to innovative ideas of Professor Manfred Schroeder. [Number Theory in Science and Communication, 3rd ed. (Springer, Berlin, 1999).] Maximum-length sequences were implemented in many real-time analyzers for measuring impulse responses. Their autocorrelation properties are almost ideal and they are widely in use today. Benefits and limitations due to hardware constraints are briefly discussed. Another particular interesting sequence is the Fibonacci sequence. It can be created from a simple loop algorithm as a binary sequence. [H., Schmidt, ‘‘Eigenschaften und Realisierung von Fibonacci-Folgen.,’’ Proc. DAGA88, Braunschweig, p. 621]. The ratio of zeros and ones is converging to the golden ratio, 1.6180.... Its spectrum consists of peaks at frequencies and with amplitudes corresponding to the golden ratio, too. When playing such sequences with certain clock frequency, a strange tonal sound can be heard. In psychoacoustic listening tests the pitch perception and pitch strength were investigated. Moreover, intervals and melodies were played by using a midi interface and new melodic and rhythmic pieces of Fibonacci music were created and checked in listening tests.
Sound production mechanism in carapid fish: First example with a slow muscle
Authors: Parmentier Eric , Lagardere Jean Paul , Vanderwalle Pierre , Braquegnier Jean-Baptiste , Fine Michael L.
Published: October 2013

Fish sonic swimbladder muscles are the fastest muscles in vertebrates and have fibers with numerous biochemical and structural adaptations for speed. Carapid fishes produce sounds with a complex swimbladder mechanism including skeletal components and extrinsic sonic muscle fibers with an exceptional helical myofibrillar structure. To study this system we stimulated the sonic muscles, described their insertion and action, and generated sounds by slowly pulling the sonic muscles. We find the sonic muscles contract slowly, pulling the anterior bladder and thereby stretching a thin fenestra. Sound is generated when the tension trips a release system that causes the fenestra to snap back to its resting position. The sound frequency does not correspond to the calculated resonant frequency of the bladder, and we hypothesize that it is determined by the snapping fenestra interacting with an overlying bony swimbladder plate. To our knowledge this tension release mechanism is unique in animal sound generation.
Sound communication by the forceps fish, Forcipiger flavissimus (Chaetodontidae)
Authors: Boyle Kelly S. , Tricas Timothy C.
Published: October 2013

The forceps fish, Forcipiger flavissimus (family Chaetodontidae), lacks the anterior swim bladder horns and laterophysic connection that are proposed to improve processing of acoustic signals in the genus Chaetodon. Despite the lack of hearing specializations, laboratory experiments using hydrophones synchronized to video revealed the forceps fish produce at least three sounds: (1) a pulse (21-ms duration, peak frequency=318 Hz) associated with rapid cranial elevation, (2) a low-frequency pulse (9-ms duration, peak frequency=41 Hz) associated with anal fin retraction and elevation, and (3) a high-frequency broadband click (3-ms duration, peak frequency=7924 Hz) associated with tail slap behavior. Auditory evoked potential experiments demonstrate that hearing thresholds for this species are 10–21 dB higher than Chaetodon in the 200–600-Hz band. High-speed kinematic analyses show that motor movements associated with some acoustic behaviors are different than those in Chaetodon, thus the presence of sound production may be the ancestral state for the family but the mechanisms are divergent. Field observations on Hawaiian reefs reveal that forceps fish occur in pairs and trios that may be haremic, and use acoustic communication among group members.[Work supported by NSF IBN0137883 to TT.]
Transmission of air gun array signals in Australian waters
Authors: McCauley Robert D. , Rennie Susan J. , Hughes John R.
Published: October 2013

Received air gun array signal parameters from 15 seismic surveys in Australian waters have been analyzed. Measurements include sources from 1115 to 4900 cui (18.3 to 80.3 L), ranges of hundreds of meters to thousands of kilometers along travel paths of 15 m to full ocean depth. For any array there may be large (±9 dB) difference in received level between consecutive signals, especially if two 3-D arrays are operated alternatively. All arrays demonstrate horizontal directivity, being typically omnidirectional below nominally 50 Hz but focusing higher frequency energy about their longer axis. Three-dimensional arrays tend to be square and 2-D arrays rectangular with the long axis across track; thus 2-D arrays are more focused. At a nominal range, differences of up to 40 dB were found when comparing small arrays operating in shallow water with large arrays in deeper water. For example, a 2500-cui array transmitting in 70 m water had no waterborne energy at 20-km range whereas a 4900-cui array operating on the shelf slope was detectable via a deep sound channel path at 2000-km. This large variation in received levels under different scenarios implies similar differences in environmental implications.
An advanced 3-D scattering model for squid
Authors: Jones Benjamin A. , Lavery Andone C. , Stanton Timothy K.
Published: October 2013

A three-dimensional, acoustic scattering model for squid has been developed that incorporates high-resolution, spiral computerized tomography (SCT) scans of squid morphology. This model numerically implements the distorted wave Born approximation (DWBA) for an inhomogeneous body using a combined ray trace and volume integration approach. SCT scans of squid, taken in air, revealed detailed morphology of the animal including the interior cavity of the mantle. The model accounts for these features with volume elements that are small (less than 1/20 the wavelength) for the frequencies of interest (0–120 kHz). Target strength predictions are compared with published data from live, freely swimming squid. Although only two materials, mantle tissue and seawater, are used to represent squid in this study, our model can be easily generalized to include many distinct, weakly scattering regions within a volume. Ranges of validity with respect to material properties and numerical considerations are explored using benchmark computations with such simpler geometries as spherical and cylindrical shells.
Predictions of acoustic scattering by a fish school
Authors: Gaumond Charles F. , Baer Ralph N.
Published: October 2013

A theory originally developed by Richard Love [J. Acoust. Soc. Am. 64, 571–580 (1978)] is used to model scattering by a school of fish. In order to incorporate propagation effects, this model has been integrated into a modified version of the RAM acoustic propagation model developed by Michael Collins. Running the integrated model over a sequence of frequencies results in predictions of the time and frequency response of broadband signals scattered by fish schools. Using an ensemble of fish school realizations lets us develop features that describe the response of a fish school to the acoustic signals. These features in turn allow separation of returns from a target from those from interfering schools. [Work supported by the Office of Naval Research.]
Swimbladder morphology and target strength of myctophid fish of the northwestern Pacific
Authors: Yasuma Hiroki , Miyashita Kazushi , Sawada Kouichi , Aoki Ichiro
Published: October 2013

Swimbladder shapes of fish from 14 myctophid species captured around Japan were measured using an x-ray method to estimate the theoretical target strength. Using those x-ray images, the fish were classified into bladder species and nonbladder species according to the presence of the gas. Five species had no swimbladder in any body size range examined. Others contained bladder and nonbladder fishes in relation to growth. The growth of swimbladder length was not proportional to that of body length (allometric growth) in some bladder fishes. Based on morphological parameters of the body and swimbladder, the relationships between body length and target strength from 38 to 200 kHz were estimated using theoretical acoustical backscattering models. Estimated values of target strength showed greater than 10-dB differences between bladder and nonbladder fishes, even when the fish were of equivalent size. Because of the allometric growth of the swimbladder, values of the target strength were not proportional to the square of the body length in most bladder species. In addition, larger fishes (over 60 mm) of Myctophum asperum showed regressive growth of the swimbladder (or target strength), suggesting that the use of the 20log relationship is inappropriate for bladder species of myctophid.
In situ measurement of target strength, tilt angle, and swimming speed of Boreopacific gonate squid (Gonatopsis borealis)
Authors: Sawada Kouichi , Takahashi Hideyuki , Abe Koki , Takao Yoshimi
Published: October 2013

Target strength (TS), mantle length (ML), swimming speed, and tilt angle of Boreopacific gonate squid Gonatopsis borealis were measured using an acoustical-optical composite system (J-QUEST) in the North Pacific Ocean. The J-QUEST consists of a quantitative echosounder operating at 70 kHz and a high-sensitivity stereo video camera system installed in a housing resistant to pressure at the depth of 300 m. In the daytime, Boreopacific gonate squids were seen at the J-QUEST depth of 230 m by the stereo video camera. Swift vertical movements were also observed on the echogram at the same time. Swimming speeds and tilt angles were estimated by tracking echoes from the same squid. Estimated average swimming speed was over 1 m/s and tilt angles were almost vertical. Average TS calculated from squidlike echoes was −54.1 dB and average ML calculated from the stereo video images was 23.9 cm with standard deviation of 5.9 cm. Standardized TS by the squared ML was −81.9 dB. In the nighttime, a Boreopacific gonate squid (estimated ML 37 cm) at the J-QUEST depth of 25 m was observed preying on one Japanese anchovy, Engraulis japonicus, in an aggregation with estimated average length of 12.3 cm.
Estimation of swimming behavior and backscattering pattern of Antarctic krill using echo-trace-analysis
Authors: Amakasu Kazuo , Furusawa Masahiko , Ando Sakiko
Published: October 2013

Echo-trace-analysis was applied to single echo-traces of Antarctic krill to estimate in situ swimming orientation, swimming speed, and backscattering pattern. Acoustic data were collected with a split-beam echosounder operating at 70 kHz on 11 January 2005 during the Southern Ocean survey by the training vessel Umitaka-maru of Tokyo University of Marine Science and Technology. While the acoustic data were collecting, the ship speed was 2 knots. A pulsewidth and a pulse-repetition-period of the echosounder were 0.6 ms and 0.27 s, respectively. Krill aggregations were observed at the depth range 15–30 m from the hull-mounted transducer and at upper and lower edges of them some single echo-traces were visually recognized on echograms. In this work, these echo traces were analyzed. As preliminary results, the average swimming orientation was 4.0 deg with a standard deviation of 14.2 deg and the average swimming speed was 0.33 m/s with a standard deviation of 0.16 m/s. The average swimming orientation was close to the orientation observed with a video plankton recorder by Lawson et al. [J. Acoust. Soc. Am. 119(1), 232–242 (2006)]. The estimated backscattering patterns showed peaks at incident angles around −10 to 10 deg and were similar to the patterns predicted by theoretical models.
Multiple-angle acoustic scattering and classification of zooplankton
Authors: Roberts Paul L. D. , Jaffe Jules S.
Published: October 2013

The use of multiple-angle acoustic scattering to discriminate between two ecologically important classes of zooplankton’ copepods and euphausiids, is proposed. The distorted wave Born approximation is used to model the multiple-angle scatter from a linear array of transducers designed to be practical for field deployment. Using a large set of noisy training and test data generated from uniformly random length and three-dimensional orientation distributions from each class of scatterers, the performance of classification algorithms in several feature spaces is evaluated. The results show a marked improvement in classification performance as additional angles, and larger angular separations, are included in the classifier. Interestingly, even in the case of uniformly random three-dimensional scatterer orientation, low classification error (∼5%) can be obtained. These results hold promise for substantially improving the classification of fluidlike zooplankton in situ using multiple angle scatter obtained with a simple collection geometry.
Numerical solutions of the Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation satisfying the Rankine-Hugoniot condition
Authors: Pinton Gianmarco , Trahey Gregg
Published: October 2013

A numerical method that solves the KZK equation and satisfies the Rankine-Hugoniot relation for shock-wave propagation is described and characterized. By comparison with a known planar solution, it is demonstrated that current numerical methods in both the time and frequency domains predict a shock front that is stationary relative to the propagation phase and that the proposed method predicts the correct speed. These methods are then compared in the context of shock-wave lithotripsy and high intensity focused ultrasound. At the focus, axisymmetric shock-wave lithotripter simulations show that the Rankine-Hugoniot method predicts peak positive pressures that are 20% smaller, peak negative pressures that are 10% larger, and a full width at half maximum that is 45% larger. High-intensity focused ultrasound simulations for an axisymmetric transducer in water have even larger variations in peak positive pressures and intensity but smaller variations in peak negative pressure. Simulations for a rectangular transducer in tissue, where absorption is more prominent, exhibit smaller but significant variations in peak pressures and intensity. Satisfying the Rankine-Hugoniot condition plays an important role in numerical simulations of the KZK equation. [This work was supported by NIH Grants R01-HL075485 and 1R01-CA114093-02.]
Bubble responses to lithotripsy shock waves
Authors: Kreider Wayne , Bailey Michael R. , Sapozhnikov Oleg A. , Crum Lawrence A.
Published: October 2013

The responses of bubbles subjected to a lithotripsy shock wave have been investigated numerically and experimentally to elucidate the role of heat and mass transfer in the underlying dynamics of strongly excited bubbles. Single spherical bubbles were modeled as gas-vapor bubbles by accounting for liquid compressibility, heat transfer, vapor transport, vapor trapping by noncondensable gases, diffusion of noncondensable gases, and heating of the liquid at the bubble wall. For shock-wave excitations, the model predicts bubble growth and collapse, followed by rebounds whose durations are significantly affected by vapor trapping. To experimentally test these predictions, bubble rebound durations were measured using passive cavitation detectors, while high-speed photographs were captured to evaluate the local cavitation field and to estimate radius-time curves for individual bubbles. Data were acquired for bubbles in water with varying temperature and dissolved gas content. Measurements verify that vapor trapping is an important mechanism that is sensitive to both temperature and dissolved gas content. While this work focuses primarily on individual bubbles, some bubble cloud effects were observed. Analysis with a simple multibubble model provides noteworthy insights. [Work supported by NIH T32-EB001650, NIH DK43881, and NSBRI SMS00402.]
Characterization of the YDME FEP-BY02 tumor therapy system
Authors: Cunitz Bryan , Mitchell Stuart , Wang Yak-Nam , Dunmire Barbrina , Kaczkowski Peter
Published: October 2013

The YDME FEP-BY02 is an extracorporeal tumor therapy device that has been in clinical use in China for several years. In the USA, this device is currently under investigation for the treatment of pancreatic cancer. Prior to being submitted for an application for an Investigation Device Exemption (IDE) with the FDA, the device will be required to undergo a thorough characterization of all systems involved in patient treatment. The purpose of this research is to characterize the FEP-BY02 and obtain data for an IDE application to the FDA for the treatment of pancreatic cancer using the FEP-BY02. A series of acoustical characterization, in vitro, and ex vivo tests are being conducted to validate the company’s preclinical and clinical experience in China. Comparisons between three methods (radiation force balance, fiber-optic hydrophone, and scattering hydrophone) for measuring/determining focal intensities will be used to assess the validity of the measurement techniques and evaluate acoustic output over the functional input range of the FEP-BY02. Transparent gels impregnated with thermally sensitive markers will be used to visualize lesion formation and evaluate lesion characteristics with respect to input parameters. Thermocouples implanted in tissue mimicking thermal gels and ex vivo tissue will be use to evaluate the thermal response with respect to input parameters. Preliminary data indicate that the therapeutic ultrasound treatment system forms consistent lesions at the desired target.
Multimodality tissue-type imaging of prostate cancer
Authors: Feleppa Ernest , Dasgupta Shreedevi , Ramachandran Sarayu , Porter Christopher , Dail David , Lacrampe Marc
Published: October 2013

Unlike many tumors, prostate cancer cannot be imaged reliably by any single, existing, conventional modality. This makes guiding biopsies, targeting therapy, and monitoring effects problematic. Therefore, our objective is to improve significantly the depiction of prostate cancers using multimodality, multifeature techniques combined with nonlinear classifiers such as artificial neural networks (ANNs) and support vector machines (SVMs). Our previous studies show encouraging potential for tissue typing and imaging based on ultrasound spectrum analysis using ANNs and SVMs that produce ROC-curve areas of 0.84 to 0.88 compared to 0.64 for conventional ultrasound imaging. Similar studies by others have shown that magnetic-resonance spectroscopy can produce comparable ROC-curve areas based on the ratio of choline and creatine to citrate. Because these two modalities sense entirely distinct properties of tissue, i.e., microscopic mechanical properties by ultrasound and chemical properties by magnetic resonance, their combination should markedly improve classification performance in distinguishing between cancerous and noncancerous prostate tissue. We have undertaken preliminary studies incorporating these two modalities. These studies demonstrate the feasibility of coregistering features from each modality and generating new, combined-modality images that exploit the attributes of both modalities.
Validating the theoretical framework relating ultrasonic spectrum-analysis parameters to scatterer properties
Authors: Dasgupta Shreedevi , Feleppa Ernest , Mamou Jonathan , Rondeau Mark
Published: October 2013

Existing theoretical frameworks for ultrasound spectrum analysis relate properties of backscattered echo signals from tissues to scatterer properties. However, the reliance of these frameworks on numerous key assumptions may not be appropriate for evaluating tissue properties. The objective of our studies is to validate those assumptions or reduce dependence on them so that estimates of scatterer properties can be made with greater confidence. Ultrasound rf data were acquired from isolated, uveal melanoma cells suspended in liquid media using center frequencies of 10 and 35 MHz. Average cell size was 12 μm and concentrations ranged from 1.3×108 cells/ml to 2.0×106 cells/ml. Theoretical spectral-parameter values predicted by the Lizzi framework were calculated using known values for size and concentration and published values for sound propagation velocity and acoustic impedance. Normalized spectral parameters were computed from the experimental rf data using standard Fourier methods. Predicted and experimental values for the slope, midband, and intercept parameters agreed to within 11%. Initial results tend to validate the theory at these scatterer concentrations. Future work will provide more insight into scattering behavior under a greater variety of conditions, e.g., scatterer sizes and concentrations.
Development of shear-horizontal–surface-acoustic wave (SH-SAW) sensor for liquids
Authors: Kondoh Jun , Shiokawa Showko
Published: October 2013

Acoustic-wave devices have been applied as chemical and physical sensors for gas and liquid phases. Since the surface acoustic wave (SAW) on a 36°-rotated Y-cut X-propagating LiTaO3 single crystal (36YX.LT) is in the shear horizontal (SH) mode, SH-SAW devices have been applied as liquid-phase sensor. In this paper, we present fundamental properties of the SH-SAW sensor and its applications. When a liquid is loaded on the SH-SAW propagation surface, evanescent fields of the SH displacement and piezoelectric potential penetrate into the liquid. Evanescent fields are influenced from the liquid, so phase velocity and amplitude of the SH-SAW are perturbed. By detecting the change, liquid-phase sensor is realized. Based on the theoretical calculation, the SH-SAW sensor is influenced by liquid properties, i.e., density and viscosity products, relative permittivity, and conductivity. For simultaneous detection of these properties, a three-channel SH-SAW sensor is fabricated. Evaluation of mixed solutions of glucose and ethanol is carried out using the sensor. The results indicate that the three-channel SH-SAW sensor can be applied to a fermentation monitoring system.
A multidimensional overview for ultrasonic motor driven loudspeaker development
Authors: Negishi Hirokazu , Ohga Juro , Ohga Juro
Published: October 2013

Twelve years of history for the development activity of the ultrasonic motor driven loudspeaker show a multidimensional aspect. Three main axes are geography, frequency, and mechanical impedance. Geography came first since initial conception was in the UK, yet the prototyping was in Japan. The origin was an idea for a stepping motor driven digital loudspeaker that was to address improving abnormalities coming from the fundamental resonant frequency, the so-called ‘‘F0.’’ Consultation revealed the idea was weak but unexpectedly ‘‘ultrasonic motor’’ was recommended. This led the prototyping to be in Japan, where the invention and development of the motor took place. The second is frequency. For audible sound reproduction, inaudible ultrasonic frequency is employed. Although combination of these two regions in frequency is not new for sound reproduction, a couple between the bottom end of the audible sound reproduction and the ultrasonic motor is completely new for this arena. The third is mechanical impedance since convention is low whereas this one is high. Actually, this is the core of the attempt as most abnormalities around ‘‘F0’’ stem from weak mechanical impedance. Other axes also exhibit contrast against conventions such as linearity, controlling, driving, and lifetime of the motor itself, as well as configuration of the sounding mechanism.
Loudspeaker using continuous revolution of a piezoelectric ultrasonic motor
Authors: Ohnuma Yuta , Iwaki Yusuke , Ohga Juro , Negishi Hirokazu , Maeda Kazuaki
Published: October 2013

Volume displacement of a direct radiator loudspeaker diaphragm is inversely proportional to the square of its signal frequency. The lowest frequency of a flat response is restricted by the diaphragmfs fundamental resonance frequency. Therefore, a loudspeaker diaphragm for radiation of a low-frequency signal shall have large amplitude and low resonant frequency. The authors propose the application of a piezoelectric ultrasonic motor for this purpose. It produces a completely controlled large output force because its output mechanical impedance is much greater than any conventional transducer or motor. An ultrasonic motor whose stator is connected to a direct-radiator loudspeaker cone diaphragm by a rod and whose rotor is loaded by a heavy metal ring rotates with a constant velocity. Modulation of the velocity by the audio signal causes driving force to the diaphragm because a heavy ring with large inertia tends to rotate with constant velocity. This paper reports construction of a practical experimental model and its output sound pressure characteristics.
Atomization of high-viscosity materials by one-point convergence of sound waves radiated from an aerial ultrasonic source using a square transverse vibrating plate
Authors: Miura Hikaru
Published: October 2013

It is difficult to atomize high-viscosity materials such as oil without contact; however, it is possible to do so using intense aerial ultrasonic waves. As a sound source for that purpose, an aerial ultrasonic source with 20-kHz resonance frequency was used along with a square transverse vibrating plate that has the nodal mode of vibration amplitude in the shape of a lattice. The source radiates four-directional sound waves in the far field. To obtain high sound pressure in the near field, radiated sound waves were converged using several flat boards and four parabolic reflective boards placed near the source. Sound pressure reaches 6.5 kPa (S.P.L. 170 dB), a very high level, at the convergent point. Scattering and atomization of the high-viscosity materials were examined at the point of convergence. Results show the following. Atomization by a sound wave is possible in the case of high-viscosity materials. The higher the sound pressure, the shorter the beginning time of atomization becomes. The distribution of the atomized particles diameter is 0.05–0.22 mm at the movement viscosity of 10000 cSt.
Ultrasonic complex vibration converters using different sound velocity metal ring pairs with slanted thickness
Authors: Tsujino Jiromaru , Ueoka Tetsugi , Kishimoto Goh , Karatsu Rohei
Published: October 2013

The ultrasonic complex vibration systems are effective for various high power applications. New complex vibration converters using different sound velocity metal ring pairs with slanted thickness are proposed and studied. Two different sound velocity rings with a slanted surface along the diameter are superimposed. The converter ring pair may be installed in any place of a longitudinal vibration system and driven by a longitudinal vibration source. The system is driven transversally according to traveling time difference between both sides of the converter. The vibration rod vibrates in elliptical to circular locus in the case where these two natural frequencies are adjusted as phase difference is near to 90 deg. Thus, various one-dimensional complex vibration systems are obtained. Piezo-ceramics cut or polarized slanted may be used. The 18-mm-diam converter for 27-kHz system consists of a phosphor bronze and stainless steel rings. The rings are cut slanted, 1.5 to 6.5 mm in thickness at outer diameter, and superimposed to an 8-mm-thick ring. Two or three converters are available for more complicated vibration modes. Using 27- and 150-kHz complex vibration systems, 1.0-mm-thick aluminum plates and coated thin copper wires for IC cards were welded directly with material strength.
Music as a vehicle to do science in the elementary classroom
Authors: Hansen Uwe J.
Published: October 2013

During the past several years, a number of workshops were conducted for public school teachers at the elementary levels. Training and materials were provided to help teachers use music as a vehicle to introduce science concepts. Tools used in these workshops include a long spring to introduce standing waves and the concept of harmonics, a monochord to relate frequency ratios to musical intervals, and simple computer software to introduce wave addition and spectral analysis. All of these will be demonstrated and ways of introducing them in the elementary classroom will be discussed. [These workshops were supported with ASA and Eisenhower funds.]
Exciting demonstration in acoustics by high-school teachers’ group: ‘‘Stray Cats.’’
Authors: Ueno Kanako , Arai Takayuki , Satoh Fumiaki , Nishimura Akira , Yoshihisa Koichi
Published: October 2013

In Japan, to get students interested in a subject, high-school teachers often form a group to share their ideas and inventions on education. ‘‘Stray Cats’’ is one of the most active groups in physics. The group has been proposing many exciting demonstrations, which were contrived to support students’ learning process with intuitive understanding of physics. Here, instead of using commercial equipment, they developed simple teaching tools that show physical phenomena in an exciting and attractive way, using quite common materials and daily goods. For example, the velocity of sound is measured by a pipe filled with a gas (air, CO2, helium, etc), setting a loudspeaker and two microphones in the pipe. Interference of sounds is demonstrated by two pipes with attached cone-shaped horns at one end, which collect a source sound in different phase, and merging them into one at the other end, which produce louder or quieter sound as a result of interference. Hitting or rubbing different length of aluminum rods aids students’ understanding of longitudinal waves and transverse wave with the relationship between rod’s length and pitch, as well as a pleasant experience with beautiful tones. These educational tools will be presented with videos taken with the Stray Cats group.