bluuebunny/crossref_metadata_2025 huggingface dataset:
Reduction of transmitted power on a plane by using mode pair cancellation
Authors: Yamazaki Toru
Published: November 2016

Reduction of structure-borne sound is an important issue for industry mechanical products. This paper presents a new idea for controlling structural intensity (SI) on panel structure derived from a cancellation of SI due to mode pairs of multiple roots. At first the modal formulation of SI on a flat plate is summarized. Next we discuss the change of SI on a flat plate by attaching a reinforcement beam cross the plate in one direction. It is shown that this attachment give multiple natural frequencies, and their mode pairs and the pairs of modal components of SI are in same phase in the area of half of the plate and in anti-phase in that of the other half. Then the modes and modal components of SI can be said to be canceled by each modal pairs in the area of half on the plate. Based on this cancellation due to modal pairs, a new method for reducing transmitted power to a given area on the plate has been derived and proposed by attaching a beam on the plate for providing partial symmetry on the plate. It is demonstrated that the partial attachment of a beam on the plate based on the proposed method can reduce the transmitted power to the given area by the cancellation due to the pairs of SI modal components.
Active control of bending waves propagating in an orthotropic rectangular panel
Authors: Iwamoto Hiroyuki , Tanaka Nobuo
Published: November 2016

Due to the recent advances in microprocessors, active control of a flexible structure has become a realizable method for suppressing the vibration. Conventional modal-based method encounters difficulties in controlling a distributed parameter structure, since such a structure has an infinite number of vibration modes. To overcome this problem, active wave control has been studied in recent years. This paper presents an active wave control of an orthotropic rectangular panel by expanding the conventional active wave control method for a two-dimensional structural case. First, a transfer matrix method for a rectangular panel is introduced to describe the wave dynamics of the structure. This is followed by the derivation of feedforward control laws for absorbing reflected waves or eliminating transmitted waves. In the proposed method, the control laws are including the modal actuation scheme for uncontrolled direction. Then, from a viewpoint of numerical analyses, basic properties of the proposed method are verified. It is found that the reflected wave absorbing control enables the inactivation of all vibration modes in the controlled direction and the transmitted wave eliminating control enables the generation of an almost vibration-free state.
Formants in speech perception
Authors: Kiefte Michael
Published: November 2016

Formants, or vocal-tract resonances, have played a dominant role in the study of both speech production and perception, particularly with vowels. They form the basis of descriptions of speech in phonetics, speech pathology, speaker verification, sociolinguistics, language acquisition, as well as in many other fields. In contrast, work in engineering applications of speech processing—specifically automatic speech recognition—typically ignores formants in favor of acoustic properties that are significantly easier to extract but which make no assumptions regarding the nature of speech acoustics. This talk describes studies that explore how listeners process formant-like information in speech and how this evidence might relate to speech perception.
Comparison of various methods of nonlinear signatures extraction
Authors: Sutin Alexander
Published: November 2016

Nonlinear Acoustic NDE (NA NDE) methods are very sensitive to defect presence and currently number on publications on this matter exceed several thousand. Despite intensive research of NA NDE, these methods are still do not widely used in practice and the goal of this presentation is to give review of various methods of nonlinear signatures extraction and to show advantages on some of them in the comparison with the others. The major part of the NA NDE was applied for characterization the tested part as whole. These methods include: High Harmonic Generation, Nonlinear Resonant Ultrasound Spectroscopy (NRUS), Amplitude Dependent Internal Friction, Nonlinear Wave Modulation Spectroscopy (NWMS) or Vibro Acoustic Modulation (VAM), Slow Dynamics Diagnostics (SDD), Nonlinear Reverberation Spectroscopy (NRS) or Nonlinear Impact Resonance Acoustic Spectroscopy (NRAS), Nonlinear Coda Wave Interferometry, Bi Spectral and High Order Statistic Analysis, Subharmonic and Ultraharmonic Methods. The methods that can provide nonlinear imaging and damage localization include: Nonlinear Time Reversal Acoustics (NTRA) or TR NEWS, Nonlinear Harmonic Imaging, Nonlinear Acoustic Tomography, Pulse Modification of Vibro Acoustic Modulation (VAM), Nonlinear Guided Wave Imaging and Tomography, Subharmonic and Ultraharmonic imaging, Nonlinear Structural Intensity.
Retreiving global nonclassical nonlinearity parameters from local measurements
Authors: Lott Martin , Remillieux Marcel , Le Bas Pierre-Yves , Ulrich Timothy J. , Garnier Vincent , Payan Cedric
Published: November 2016

We demonstrate the equivalence between local and global measures of nonclassical nonlinear elasticity in a slender resonant bar of Berea sandstone. Nonlinear effects are first measured globally using Nonlinear Resonance Ultrasound Spectroscopy (NRUS), which monitors the relative shift of the resonance frequency as a function of the maximum dynamic strain in the sample. Subsequently, nonlinear effects are measured locally at various positions along the sample using Dynamic Acousto-Elasticity Testing (DAET). After processing the DAET signals and correcting for three-dimensional strain effects, it is shown that by numerically integrating these corrected data along the length of the sample the NRUS global measures are retrieved almost exactly.
Nonlinear ultrasonic phased array for closed crack imaging
Authors: Ohara Yoshikazu , Yamanaka Kazushi , Mihara Tsuyoshi
Published: November 2016

In nondestructive ultrasonic inspection, closed cracks can lead to the underestimation or overlook, resulting in the catastrophic accidents. To solve this problem, nonlinear ultrasonics has been expected as a most promising approach. In nonlinear ultrasonics, by irradiating large amplitude, the nonlinear interaction between closed cracks and ultrasonics generates nonlinear components. Among them, we found that subharmonics has a higher selectivity than the others including higher harmonics. We also found that the subharmonics has higher temporal resolution, providing the high spatial resolution in ultrasonic imaging. Based on these findings, we have developed a novel imaging method, subharmonic phased array for crack evaluation (SPACE), based on the subharmonic generation at closed cracks due to large-amplitude short burst waves input and phased array imaging with frequency filtering. As a result of applying SPACE to closed-crack specimens, SPACE visualized the closed part of cracks, which were not observed in the conventional methods. It was substantiated that SPACE is useful in accurately measuring closed-crack depths.
Defect detection in a concrete bridge by a non-destructive technique
Authors: Abe Masato , Fujioka Toyota , Nagata Yoshifumi
Published: November 2016

Post-tensioned prestressed concrete is a method for overcoming concrete's natural weakness in tension, and it is used widely to produce bridges with a longer span. Because of poor workmanship or quality control during construction, however, sometimes the ducts containing the prestressing tendons are not fully filled, leaving voids in the grout where the steel is not protected from corrosion. Therefore, we propose a method to detect such the voids using multiple sensors and an impulse hammer. The sensors pick up the vibration wave caused by the impulse hammer. The experimentally picked-up vibration waves are compared with those simulated by the Finite-Difference Time Domain (FDTD) method, and it is found that these two waves quite similar. It is also found from some experiments for the bridge pier that we can detect (1) the presence or absence of a void and (2) the void position.
The role of diffraction in sound transmission through air-water interfaces
Authors: Godin Oleg A.
Published: November 2016

Ray-theoretical modeling and elementary considerations that are based on plane-wave reflection coefficients predict very weak sound transmission through air-water interfaces because of a large contrast in the acoustic impedances of air and water. With ray-type geometric contributions to transmitted acoustic energy being suppressed by the disparities in the sound speeds and densities, wave diffraction often plays the dominant role in coupling acoustic fields in air and water. In particular, acoustic diffraction leads to the phenomenon of anomalous transparency of air-water interfaces for low-frequency sound. Almost all the energy that is radiated by shallow compact underwater sound sources is transmitted into air [O. A. Godin, Phys. Rev. Lett. 97, 164301 (2006)]. Other scenarios, in which diffraction plays a critical role in sound transmission through air-water interfaces, include excitation of Scholte-type surface waves in water by sonic booms and propagation of Lamb waves along the ocean surface. The paper will review the theory and experimental evidence of the anomalous transparency of air-water interfaces for finite-size underwater sound sources and for coupling of acoustic fields in the ocean and atmosphere by Lamb and Scholte-type surface waves.
Reciprocity calibration of underwater acoustic transducer in a reverberation pool
Authors: Shang Dajing , Li Qi , Sun Jundong
Published: November 2016

A new underwater acoustic transducer reciprocity calibration method was put forward in this paper. This calibration was finished by the space-averaging in the reverberation pool, and the influence of normal mode interference was eliminated, so the reverberation field acoustic parameters were obtained in the reverberation pool. The calibration can be set up in a small reverberation pool. In the case of the same frequency range acoustic transducer calibration, the reverberation pool for reverberation method reciprocity calibration can be smaller than the free-field pool for free-field reciprocity calibration. The reverberation field reciprocity constant was determined by measuring the reverberation time, the single-frequency sine signal was emission by the sound source higher than the cutoff frequency, the transmitting transducer and receiving transducer was space-averaged in the area of the reverberation, and the corresponding electrical parameters were obtained, so the receiving sensitivity for the reciprocity transducer and the testing hydrophone was calculated. The testing and the results of the reverberation calibration are presented in this paper. The error between the hydrophone calibration by the reverberation method and the factory free field calibration was less than 1.4 dB, and the A kind of measuring uncertainty is less than 0.13 dB. This method can be applied to all kinds of hydrophones and transducer calibration.
Sound exposure level and energy spectral density of underwater explosions in shallow water over a coral substrate off the southern coast of O`ahu, Hawai`i
Authors: Soloway Alexander G. , Dahl Peter H. , Shannon Lee H.
Published: November 2016

This work presents the sound exposure levels (SEL) and energy spectral densities (ESD) from underwater explosions measured in shallow water (10-18 m) at distances of 500 to 1500 m at the Pu’uloa Underwater Detonation Range off the southern coast of Oahu. Nine explosive charges, with TNT-equivalent weights of 2.2 to 8.6 kg, were detonated on a seabed characterized by a thin sand layer over limestone. The ESD of the measurements are characterized by high propagation loss in the frequency ranges 50 to 350 Hz. Previous studies have shown that this is a common characteristic of this environment with the upper and lower frequencies directly related to the geoacoustic properties of the seabed and the waveguide geometry. Unlike measurements collected in sandy environments, where SEL agreed with empirical predictions, the SEL for these measurements differ by up to 30 dB. To understand the mechanisms responsible for these lower than expected levels, a geoacoustic model for the seabed is developed using these frequencies and utilized in broadband modelling simulations. The SEL will also be calculated for these simulations and compared to the measured levels. [Research supported by Pacific Fleet with partial support from the Office of Naval Research.]
Impact of array tilting on source-range estimation based on the array/waveguide invariant
Authors: Cho Chomgun , Song Hee-Chun
Published: November 2016

Recently, the array/waveguide invariant was proposed for robust range estimation of a broadband source in a waveguide environment using a short-aperture vertical array (VA). The approach involves conventional plane-wave beamforming and exploits the separation of arrivals in beam angle and travel time. The beam angle estimate, however, can be sensitive to array tilting. In this paper, we investigate the impact of array tilting on source-range estimation based on the array/waveguide invariant. Analysis of experimental data indicates that even a small tilt angle (<2°) of a 1.2-m long VA can result in a relative range error of 20% or more for a source (9-17 kHz) at 3-km range in ~100-m deep water. Inversely, the array tilt angle can be estimated for a known source range.
A sequential filtering algorithm for range estimation of a moving ship based on striation geometric features
Authors: Ren Qunyan , Ma Li , Piao Shengchun , Guo Shengming , Liao Tianjun
Published: November 2016

There exist regular striation pattern in the broad-band noise field excited by a moving ship in shallow waters, whose time (range) frequency structure can be interpreted by the waveguide invariant theory. The striation characteristics have been exploited for underwater acoustic inversion problems, e.g., sediment geoacoustic parameter characterization. In this paper, the geometrical features of specific striations are observed for continuously ship ranging by a sequential algorithm. Comparing to matched-field processing techniques, this approach also has no requirements prior knowledge of environmental properties and burden of forward sound field calculation, which is similar to virtual receiver approach. The technique is tested on the striation fragments extracted from the ship noise data collected in Dalian 2008, and the outputs are in high agreement with in-situ GPS measurements. The results from independent runs with different initial values also suggest that this approach is robust to initial conditions in the sense of all runs can converge to the true values rapidly.
Acoustic source localization in ocean waveguides using principles of Riemannian geometry
Authors: Finette Steven , Mignerey Peter
Published: November 2016

Source localization in underwater acoustics entails a comparison between acoustic fields involving some measure of correlation, looking for similarity between the acoustic field propagated from the true source location and replica fields propagated from different locations in the waveguide. The uniqueness of the deterministic Green function between pairs of source-receiver positions forms the basis for the solution to this inverse problem. We consider a novel approach to source localization based on non-Euclidean geometry, where the “distance” between cross-spectral density matrices (CSDMs) is used to estimate the spatial location of the source. The traditional Euclidean distance is not necessarily appropriate because CSDMs are not arbitrary points in space; rather, they form a manifold constrained by the facts that CSDMs are both Hermitian and positive definite. These properties naturally lead to the interpretation of geodesic distance between CSDMs as a measure of similarity between acoustic fields with this minimum distance, parametrized by replica source location, establishing an estimate of the source position. We discuss the underlying concepts and present simulation results for a waveguide with internal wave-induced ocean variability. Several Riemannian metrics are considered and compared to more traditional approaches to matched-field localization. [Work supported by the Office of Naval Research.]
A hybrid impedance measurement method to inversely determine the impedance of finite porous absorber material samples
Authors: Opdam Rob , Müller-Giebeler Mark , Vorländer Michael
Published: November 2016

The determination of complex angle-dependent reflection factors is not common practice. Mostly, because existing methods are complicated and very time-consuming. This work presents a method that only needs a single sound pressure measurement of a finite porous absorber piece, placed in a semi-anechoic chamber, as input data. The complex pressure data obtained of the measurement are compared with that of a finite element method (FEM) simulation, which is based on the same geometric dimensions of the material sample as in the measurement, but with an arbitrary porous material. With a non-linear fitting algorithm, the simulated complex pressure data are adjusted to fit the measured data iteratively by changing the absorber model parameters (porosity, flow resistance, etc.) in the FEM simulation. When the simulated and measured results are identical within a defined threshold, the characteristic absorber properties are found and with that the angle-dependent complex reflection factors are determined. Applying this inverse approach allows also for a correction of the edge effects of the finite material sample, such that the found impedance is the impedance as measured on an infinite extended material sample and it also determines the individual material properties as porosity and flow resistivity of a porous material.
Evaluating the auralization of a small room in a virtual sound environment using objective room acoustic measures
Authors: Ahrens Axel , Marschall Márton , Dau Torsten
Published: November 2016

To study human auditory perception in realistic environments, loudspeaker-based reproduction techniques have recently become state-of-the-art. To evaluate the accuracy of a simulation-based room auralization of a small room, objective measures, such as early-decay-time (EDT), reverberation time, clarity, interaural cross-correlation (IACC), and the speech transmission index were measured in an IEC listening room for 28 source-receiver combinations. The room was then modeled in the room acoustics software ODEON, and the same objective measures were also evaluated for the auralized version of the room. The auralizations were generated using the loudspeaker-based room auralization toolbox (LoRA; Favrot and Buchholz, 2010) and reproduced in a 64-channel loudspeaker array, set up in an anechoic chamber. Differences between the objective measures evaluated in the real and the virtual room were within about twice the just-noticeable differences for most measures, and were comparable to the median results of the study by Favrot and Buchholz, who did not consider the contribution of a real reproduction system. However, the EDT showed considerably higher errors than the other measures, even though medians were similar in the real and auralized room. This suggests that fine details in the early part of the room impulse response may be difficult to reproduce accurately.
Automatic detection and classification of toothed whale echolocation clicks in diverse long term recordings
Authors: Lindeneau Scott , Trinh Yun , Baumann-Pickering Simone , Roch Marie
Published: November 2016

We present results of classification of toothed whale echolocation clicks to species for 4 TB of recordings in the development data of 7th Intl. DCLDE Workshop. The data span multiple seasons, years, locations, and instruments. Five species were acoustically identified by analysts, and a sixth category was assigned to echolocation clicks that could not be identified to species by analysts. Methods were developed to identify periods of echolocation activity taking into account sporadic false positives that occur throughout the data, and to reduce false positives from both anthropogenic and biologic sources. Dense echolocation activity presented particular challenges for noise removal and long term recordings permitted the targeting of regions for noise estimation outside of echolocation encounters. Extracted features consisted of noise normalized cepstral characterizations of spectra, inter-click interval, and -3 dB bandwidth. These features were classified with a Gaussian mixture model (GMM). A robust scoring method was introduced to reduce outlier influence by using a per-click voting scheme within each encounter as opposed to joint likelihood scores. The error rate across 300 Monte Carlo trials on the development data set was 34.5%. When encounters from the unspecified toothed whales were removed, the error rate dropped to 15.5%.
Passive acoustic localization of North Atlantic Right Whales using a modified near-field Bartlett beamformer
Authors: Hawthorne Dean L. , Salisbury Daniel P.
Published: November 2016

Owing to the principle of least commitment, near-field beamformers can produce passive acoustic source localizations which are robust to noise and interference. The power output of a traditional Bartlett near-field beamformer may be formulated in terms of the pairwise cross correlation functions of the sensor signals. We present a modified Bartlett processor wherein the ordinary cross correlation is replaced by generalized cross correlation, generalized in both time and frequency. As an example of the utility of the technique, we present results from a six element pentagonal marine array with a baseline of approximately 15 km deployed off the coast of Virginia. Localization of synthetic FM sweeps from known source locations within the array yield deviations from the true source location as measured by GPS of less than 100 meters. Localization of actual North Atlantic Right Whale calls provide good alignment of the unknown channel arrivals and acceptably small error ellipses.
3D assimilation of Hiroshima Bay acoustic tomography data into a Princeton Ocean Circulation Model
Authors: Chen Minmo , Kaneko Arata , Zhang Chuangzheng , Lin Ju
Published: November 2016

A baroclinic data assimilation, based on the ensemble Kalman filter (EnKF) method, with coastal acoustic tomography (CAT) data is first applied to Princeton Ocean Model (POM) to elucidate a 3D structure of coastal upwelling which occurred in Hiroshima Bay due to a northerly wind from a typhoon. The CAT experiment with four acoustic stations was performed from Sept. 11 to Sept. 25, 2013, in the northern part of Hiroshima Bay, Japan. Reciprocal data were acquired at three stations and along three transmission lines with a triangular array and travel time were identified every 10 min for the first and second arrival rays which travel at different depth ranges. As for the EnKF method, the Kalman gain was determined to minimize the observed and simulated travel time differences and summations. The model error covariance was given by adding pseudorandom noises (zero mean value and one variance) with an appropriate multiplication factor to the POM result. The observation error covariance was estimated from the variation of observed travel times. A 3D structure of coastal upwelling which was difficult to be simulated by the POM was reconstructed by data assimilation and compared with the CTD result.
Current field tracking based on spatiotemporal evolution model with distributed networked underwater sensor system
Authors: Xu Wen , Zhang Ying , Chen Huifang , Yang T. C.
Published: November 2016

Distributed networked underwater sensor (DNUS) system can provide ocean measurements over a wide area with a large number of sensors. This paper studies the estimation of the two-dimensional ocean current field with acoustic travel time difference data observed by a DNUS system. Considering that the current field is correlated in time and space, we present a statistical-based tomography method based on Kalman filter to reconstruct and track the ocean current field. A spatiotemporal autoregressive (AR) model is used to describe the evolution of the current field. In the spatiotemporal AR model, the observation region is divided into sub-triangle grids. The sub-triangles are partitioned into clusters by distance and each cluster is assigned with one AR coefficient. The AR coefficients are updated adaptively with the past estimated current velocities. The proposed method is verified with the synthetic observational data generated by a barotropic ocean model and the tomography experiment conducted near Zhoushan Island, China. Compared with the regular time-independent distributed processing method, the proposed ocean current field tracking achieves a lower root-mean-square error. In addition, the proposed method is robust to the measurement link failure and burst errors commonly occurred in a DNUS system.
Mutual interpretation between B-mode image and cross-sectional acoustic microscopy
Authors: Hozumi Naohiro , Tan Wei-Chean , Yoshida Sachiko , Ogura Yuki , Kobayashi Kazuto , Yamaguchi Tadashi
Published: November 2016

Acoustic microscopy is a two-dimensional profile of an acoustic parameter such as sound speed and characteristic acoustic impedance. It may be useful to understand how practically important B-mode image looks depending on cross-sectional spatial distribution of acoustic properties. In the presentation, it will be exhibited that B-mode echo-graph can be briefly reproduced from acoustic impedance profile observed by acoustic microscope by a similar process to the time domain reflectometry (TDR), with some simple assumptions. As an example, the acoustic impedance profile of a rat cerebellar tissue was acquired by acoustic impedance microscope that was developed in our lab. The B-mode image reproduced by calculation was compared with an actually acquired B-mode image. A good agreement between these two images was seen. On the other hand, a B-mode profile may be interpreted into cross-sectional distribution of acoustic profile. As it is attributed to inverse problem, several assumptions may be required. In the calculation, strait acoustic beam and no attenuation were assumed. In addition, the B-mode profile with RF waveforms was assumed to be available. In the presentation, it will be exhibited that cross-sectional acoustic impedance profile of a shallow region of human skin can be reproduced from non-invasive B-mode scan.
In-vivo quantitative analysis of the angiogenic microvasculature in tumor-bearing rats using multiple scattering: A preliminary study
Authors: Joshi Aditya , Shelton Sarah , Papadopoulou Virginie , Lindsey Brooks , Dayton Paul , Muller Marie
Published: November 2016

We propose a method to quantify the vascular density in vascular networks using contrast-enhanced multiple scattering. We measured the diffusion constant D and transport mean free path L* from the time evolution of the incoherent intensity in a rat model of cancer. An 8 MHz linear transducer array was used to record the backscattered signals from subcutaneous fibrosarcoma tumors and control tissue. The coherent and incoherent contributions to the backscattered intensity were separated, and the growth rate of the incoherent contribution was measured, giving the D and L*, knowing the effective speed of sound. By translating the linear array along the tumor, mapping of L* was achieved. Tumors were implanted in the right flank of four rats, and the contralateral side served as control. Acoustic angiography and measurements of the incoherent intensity were performed. The mean L* values in control and tumor tissue were significantly different (105.27 + /- 30.96 micron and 41.28+ /- 14.23 micron, respectively, p = 8.4033 × 10-49). The mean distance between vessels was estimated from acoustic angiography images using Monte-Carlo simulations, and was in agreement with the experimentally calculated values of L* (r = 0.9507, p = 1.4957 × 10-9).
Fatty-acid species identification by quantitative high-frequency acoustic impedance measurements
Authors: Ito Kazuyo , Yoshida Kenji , Maruyama Hitoshi , Mamou Jonathan , Yamaguchi Tadashi
Published: November 2016

Accurate discrimination of non-alcoholic steatohepatitis (NASH) from simple steatosis is a critical issue in current clinical practice because NASH can progress to cirrhosis or even liver cancer. Some studies reported that the free fatty acids (FFA) composition of the liver changes with the progression of NASH. Therefore, an ultrasound-based diagnostic tool could be based on measurements of the acoustical properties of FFAs. This study investigated how FFAs influence the acoustical properties of liver cells at a microscopic level using scanning acoustic microscopy (SAM) with four pathological types of mouse livers, five kinds of FFAs in solution, and five kinds of FFAs in cultured cells. A SAM system based on an 80-MHz center-frequency transducer was employed. The acoustic impedance was computed from the echo amplitude and the pressure-reflection coefficient. One-way ANOVA showed statistically significant differences (p < 0.01) in acoustic impedance among pathological types. NASH was found to have the lowest acoustic impedance. Results obtained in FFA solutions and FFA-containing cultured cells also demonstrated significant differences in acoustic-impedance values (p < 0.01) for all paired tests except one (palmitate and linoleate). Therefore, these initial results suggest that NASH identification and characterization using in-vivo quantitative ultrasound methods may be possible.
A novel bone sonometer for estimation of calcaneal bone mineral density
Authors: Kaufman Jonathan J. , Luo Gangming
Published: November 2016

This study evaluated a new clinical ultrasound device, the QRT 250, in terms of its ability to estimate BMD at the calcaneus. The QRT 250 rests on the floor and permits real-time evaluation of calcaneal BMD. The QRT 250 utilizes a novel heel positioning system that relies on an individual's foot size to locate a specific region-of interest (ROI) in the calcaneus. This feature of the device was designed to account for the relatively high degree of BMD heterogeneity associated with the calcaneus. The device measures in thru-transmission a net time delay (NTD) parameter. NTD has been shown to be highly correlated with bone mass in simulations, in vitro, and in other clinical studies. A linear regression of the NTD is used to provide an estimate of calcaneal BMD that would be measured by DXA. A clinical IRB-approved study was carried out in which 145 adults were measured at the calcaneus using ultrasound and DXA (Lunar GE PIXI; WI, USA). In addition, thirty (30) subjects were each ultrasonically measured two (2) times and the short term precision was evaluated. A linear regression showed that BMDUS = 0.12 · NTD—0.11 and that the linear correlation between BMDDXA and BMDUS was 0.89 (P<0.001). We found that calcaneal ultrasound measurements yield results that are very closely associated with those from DXA. In the short-term precision study, we found that the mean percent precision was 1.37%. In summary, the QRT 250 can be used to identify bone loss in osteoporosis and ultimately to reduce the incidence of fragility fractures.
Ultrasonic backscatter theory, method, and diagnostic instrument for cancellous bone
Authors: Ta Dean , Liu Chengcheng
Published: November 2016

Recently, significant progress has been made in the backscatter measurement of cancellous bone. In this work, we will introduce the basic theory and some key techniques for backscatter cancellous bone evaluation. Backscatter measurements in vivo were also carried out with a diagnostic instrument, and the feasibility of using the backscatter for cancellous bone evaluation was investigated. Researchers had reported conflicting associations between backscatter and bone features. Our studies demonstrated that this phenomenon was due to different signal selections. The dense cortical shell obstructs the ultrasonic evaluation of the underlaid cancellous bone in vivo. We determined the influence of the overlying cortex on the backscatter signal and proposed a compensation method for the cortical influence. Using an ultrasonic backscatter bone diagnostic instrument, the measurements were performed on 1226 adults and on 467 neonates in the calcaneus. For the adults, the backscatter was significantly correlated with the bone mineral density (BMD) of the spine and hip. The backscatter parameters were moderately correlated with the gestational age and birthweight in the neonates. The in vivo findings demonstrate the ultrasonic backscatter as a useful adjunct measurement for the multi-feature assessment of cancellous bone.
Optimization of speech presentation in mass-notification sound systems based on word intelligibility
Authors: Sakamoto Shuichi , Cui Zhenglie , Morimoto Masayuki , Suzuki Yôiti
Published: November 2016

Outdoor mass-notification sound systems can effectively convey emergency announcements over a wide area without requiring the audience to use any special devices. However, the intelligibility of speech presented via these systems is often severely degraded by long-path echoes. Under such conditions, it is important to consider robust ways of presenting speech information. Various studies have highlighted that there are many factors which affect the speech intelligibility with long-path echoes. We have focused on the effect of word familiarity and inserting pauses between the words in a speech signal. High-familiarity words are easy to understand even when presented under challenging listening conditions. By inserting pauses, speech intelligibility could be improved because more of the speech signal can be received without significant overlapping long-path echoes. In this study, speech materials were modeled based on actual sentences used in emergency notifications given via the Japanese mass-notification system, J-Alert. By using this model, the effects of word familiarity and inserting pauses on word indelibility under long-path echo were examined. The results of the experiments suggest that speech signals can be robustly understood despite long-path echoes by using high-familiarity words with adequate inter-word pauses.
The effects of wind noise on outdoor sound propagation and detection
Authors: Abbott JohnPaul R.
Published: November 2016

Wind noise is a form of pseudo-noise. It is generated and propagated by physical mechanisms that are different from acoustic noise; however, its effect on microphones and similar pressure sensitive devices is indistinguishable from acoustic noise. Wind noise is defined as the pressure fluctuations that are generated and propagated by the turbulent flow of an incompressible fluid. Acoustic noise is generated and propagated by the adiabatic compression and expansion of air. Since the effect of wind noise is the same as acoustic noise, it can have significant effect on the propagation and detection of desired acoustic signals at sonic and infrasonic frequencies. This can lead to adverse impacts on mass and early warning systems. This talk will present an overview of the effects of wind noise on outdoor sound propagation, detection, and efforts to mitigate and account for its influence on sonic and infrasonic acoustic signals. It will also discuss the potential impacts of sonic and infrasonic wind noise on mass and early warning systems.
Effects of local and global meteorological data on predicting blast noise levels
Authors: Blevins Matthew G. , Hart Carl R. , Bunkley Steven L. , Nykaza Edward T.
Published: November 2016

Predicting noise levels due to military blasts is important near training installations, since surrounding communities may be adversely affected. Prediction models, however, rely on atmospheric or weather data that is not readily available or easily attainable. In this study, blast noise level predictions 1-8 km from the source are made using two sources of meteorological data: publicly available data derived from weather stations that are tens of kilometers from a detonation site, and near-ground weather stations that are 2-6 km from the source. To predict the blast noise levels, statistical learning regression models are trained on each set of meteorological data and over 1000 measured blast events. Predictions from both meteorological data sources are compared to actual blast noise levels recorded during a field experiment by Valente et al. [2012], which were captured under a wide variety of atmospheric conditions. The root-mean-square errors for each model are compared, and the most important input parameters are identified.
Making headphones using plastic bottles and a milk carton
Authors: Seguchi Shinjiro
Published: November 2016

The SONY Science Program provides tomorrow’s principles and the opportunity for hands-on experience for children. It will hopefully motivate them to acquire skills needed to make a better society by applying the power of science. An inclusion workshop is one of the Science Programs, where children can learn about scientific principles and technology through demonstrations. Making headphones from PET bottles and a milk cartons, organized by technicians from Sony/Taiyo Corporation, is one of the topics of the inclusion workshop. Children learn how the pieces they constructed vibrate and generate sounds. The program is also designed to make the participants aware of the varied individuality of each and every one of them, and to deepen mutual understanding through this experience of diversity and inclusion.
Descriptions of sound in the textbooks of living environment studies in elementary schools and the development of a life and sound activity programs
Authors: Toyomasu Miki , Suzuki Sayo , Akitake Yoshiko
Published: November 2016

In Japan, children learn about the subject Living Environment Studies in the first and second grades at elementary school. Eight companies published the 2015-approved elementary school Living Environment Studies textbooks. In this study, we investigated and analyzed the references to sound in all the Living Environment Studies textbooks and the development of life and sound activity programs. Textbooks were found to include contents relating to nature sounds (e.g., sounds made by insects and the sound of rain); musical sounds; sounds of life (e.g., sound of toys); and sound of voices (e.g., loud screams or shrieks in response to danger seeking help), etc. We developed two activity programs, a quiz on sounds and a competition for loud voices. The purpose of these programs was to learn about enjoying “sound” and understand its role in life. These activity programs conducted in Clubs for After School Activities for Children at F city. A questionnaire survey was conducted after two activity programs. Eight children answered that the quiz on sounds was fun and nine children answered that the loud voice competition was fun (N = 14). Further investigation and improvements are required.
Speech perception and production with one level-dependent hearing protector
Authors: Giguère Christian , Laroche Chantal , Vaillancourt Véronique , Vaziri Ghazaleh , Ellaham Nicolas N. , Dajani Hilmi R.
Published: November 2016

Electronic level-dependent hearing protectors aim to enhance communications and situational awareness in the noisy workplace compared to passive hearing protectors. From a listener’s perspective, the fixed attenuation provided by passive hearing protection interferes with speech recognition in noise in users with hearing loss. From a talker’s perspective, they also disrupt the Lombard reflex and induce an occlusion effect, which leads to a reduced vocal output in noise and compounds the problem. This paper presents laboratory data on speech recognition and production in noise with one level-dependent earmuff device. The device was tested in the level-dependent mode at two different gain settings as well as in a powered OFF condition to simulate passive protection within the same device. Level-dependent hearing protection provided significant speech recognition benefits in noise compared to passive protection, especially for users with hearing loss, and performance often exceeded unprotected listening. Talker speech output levels were also found to be higher in noise when the hearing protector was operated in a level-dependent mode compared to passive protection, but not as high as when unprotected, indicating only a partial recovery of speech production mechanisms.
Continuous monitoring of fatigue process with surface wave resonance: In the case of rotating bending fatigue
Authors: Masahiko Hirao
Published: November 2016

Prediction of fatigue failure of metals has not become reality like that of earthquake despite the intensive studies over many decades. But, there is an exception. The accumulating damage and the remaining life of rotating bending fatigue can be known from the ultrasonic observations through the lifetime. Electromagnetic acoustic resonance (EMAR) makes it possible to monitor the evolution of phase velocity, attenuation, and nonlinearity of surface shear wave exited and detected exclusively by electromagnetic acoustic transducer (EMAT), which operates without any contact with the rotating shafts. The probing shear wave travels in the circumferential direction with the axial polarization and penetrates into the metal to the submillimeter depth. Clear indications occur in the attenuation and nonlinearity measurements, and tell the pertinent metallurgical events within the penetration depth. They are caused by the dislocation mobility and restructuring due to cyclic loading, and occur at the specific fractions to the fatigue life, being independent of the bending stress amplitude. Continuous observation with EMAR can only detect such precursors and tell the remaining lifetime of metal components being fatigued. Discussions are given for the mechanism being based on the replication of small cracks and the TEM observation of dislocations at the crack-tip zone.
Resonant ultrasound spectroscopy study of novel ceramics designed for high temperature hydrogen fuel cells
Authors: Gladden Josh R. , Tennakoon Sumudu , Karunarathne Ashoka
Published: November 2016

Elastic constant measurements, along with temperature and pressure derivatives, are of interest to both the physics and engineering communities. One of the most precise and efficient methods for such measurements is resonant ultrasound spectroscopy (RUS) in which the vibrational resonance spectrum of a sample is used to determine the full elastic tensor of the material. In this talk, we will present the temperature dependent elastic constants of a series of ceramics, including glass ceramics and DMMA, between room temperature and 800°C. These ceramics have been designed for use in high temperature fuel cell by LG Fuel Cell Systems. We will discuss the effects of thermal cycling. Some of the ceramics are porous in nature which increases acoustic damping. Damping mechanisms in porous materials and experimental techniques to reduce damping will also be discussed.
Non-contact acoustic manipulation in microchannel
Authors: Kozuka Teruyuki
Published: November 2016

Noncontact micromanipulation technique is needed in micromachine technology, biotechnology, and other fields. In the present paper, a standing wave field is generated in a microchannel and a geometric space, and it is possible to trap small objects at nodes of the sound pressure distribution in the medium. A microchannel and a geometric space were made at the center of a glass plate of 50 mm x 50 mm x 5 mm. In the experiment, when the liquid water containing alumina particles was injected into the microchannel on glass plate irradiated by ultrasound, the particles flowed along several layers in the microchannel. In the geometric space, the particles were trapped in the sound pressure nodes of the standing wave field. By changing the frequency, the geometric pattern of particles aggregation interestingly changed. When the geometric space is a triangular space, the particle moved toward the top from the base of the triangle. When the microchannel is branched at the half circular geometric space, it was able to control the direction of the particle flow by changing the ultrasound frequency in the branched microchannels. Moreover, a sound field was numerically simulated by FEM under the experimental conditions, and the experimental results were discussed.
A study of the limits of microparticle collection over a broad frequency range
Authors: Agrawal Prashant , Gandhi Prasanna S. , Neild Adrian
Published: November 2016

Acoustic fields can be used to collect microparticles over a wide range of frequencies. Within the ultrasonic range acoustic radiation forces cause patterns of particles to form, typically along pressure nodes. At much lower frequencies (in the order of hundreds of Hertz), the collection mechanism is inertial in nature, a particle’s inability to follow the fluid motion causes drag forces to act on the particle which are non-zero when integrated across a time cycle due to gradients in the flow field. In both cases, however, the ability to collect particles is limited by acoustic streaming—the steady state fluid flow which results from gradients in the harmonic flow field. In this study, we examine the smallest particle size that can be collected as a function of frequency. For the low frequency vibration, an open fluid chamber is oscillated in the horizontal plane, these conditions are also applied to the ultrasonic case, and the acoustic energy is kept constant across frequencies. It is found that the minimum particle size can be collected at each end of the frequency scale.
How auditory scene understanding can fail in special populations
Authors: Shinn-Cunningham Barbara , Bressler Scott , Wang Le
Published: November 2016

One way to gain insight into how the brain normally processes auditory scenes is to explore the perceptual problems in special populations. In our lab, we are studying two types of listeners who, although very different, both have trouble making sense of complex scenes: listeners with autism who are minimally verbal (MVA listeners), and blast-exposed military Veterans. Neither population shows evidence of specific deficits in how well information is encoded subcortically. However, both show deficits when it comes to analyzing sound mixtures with multiple sound sources. Neural responses from MVA listeners suggest that their brains do not automatically organize sound mixtures that typically developing listeners hear as distinct objects, which likely impairs their ability to analyze the content of one sound source in a mixture. In contrast, Veterans exposed to blast appear to have difficulties focusing selective attention on a sound source in order to select it from a mixture, consistent with behavioral deficits when trying to track one sound stream. The problems these two populations have in processing complex scenes supports the idea that successful everyday listening depends both on perceptual organization of the scene and top-down control of attention.