bluuebunny/crossref_metadata_2025 huggingface dataset:
Blind dereverberation based on auto-correlation functions of framewise time sequences of frequency components
Authors: Ota Kenko , Yanagida Masuzo
Published: October 2013

Proposed is a new blind dereverberation method based on auto-correlation function of framewise time series of each frequency component. Inverse filtering of source-microphone transfer functions is widely employed for suppressing the effects of reflected waves, but this method cannot be employed for cases where source-microphone transfer functions are not available or for time-variant cases. Several methods of spectral subtraction have been proposed to cope with these cases. However, most of them require transfer functions among sources and microphones. The proposed method, however, does not require transfer function inverse filters. Moreover, the method can handle frequency characteristics of sound paths. To realize dereverberation, it is necessary to estimate the delay time and frequency characteristics of reflection, though most conventional methods assume flat frequency characteristics. The proposed method estimates these parameters based on auto-correlation function of each time series of spectral components in frequency spectra obtained every frame-shift interval. The proposed method improves dereverberation performance, comparing with methods that assume flat frequency characteristics. The proposed method raises average segmental SNR by 3.4 dB and reduces reverberation time from 390 to 109 ms for a room employed for experiments. [Work supported by Knowledge Cluster Project, MEXT, and by Academic Frontier Project Doshisha University.]
Blind spatial subtraction array based on independent component analysis for speech enhancement and recognition
Authors: Takahashi Yu , Takatani Tomoya , Saruwatari Hiroshi , Shikano Kiyohiro
Published: October 2013

We propose a new blind spatial subtraction array (BSSA) that contains an accurate noise estimator based on independent component analysis (ICA) for the realization of noise-robust hands-free speech recognition. Many previous studies on ICA-based blind source separation often dealt with the special case of speech-speech mixing. However, such a sound mixing is not realistic under common acoustic conditions; the target speech can be approximated to a point source but real noises are often not point sources. Under the condition, our preliminary experiment suggests that the conventional ICA is proficient in the noise estimation rather than the direct speech estimation. Based on the above-mentioned findings, we propose a new noise reduction method that is implemented in subtracting the power spectrum of the estimated noise by ICA from the power spectrum of noise-contaminated observations. This architecture provides us a noise-estimation-error robust speech enhancement rather than a simple linear-filtering-based enhancement. Although nonlinear processing often generates an artificial distortion, the so-called musical noise, it is still applicable to the speech recognition system because the speech decoder is not so sensitive to such a distortion. Experimental results reveal that the proposed BSSA can improve the speech recognition rate by 20% compared with the conventional ICA.
Frequency-domain independent component analysis by overlap piecewise integration of separation processing
Authors: Noguchi Tadashige , Ota Kenko , Yanagida Masuzo , Di Persia Leandro
Published: October 2013

Conventional frequency-domain ICA yields the optimal separation for each frequency bin, but it suffers from the permutation problem. The authors have developed permutation-free ICA as a separation scheme by obtaining the separation matrix for a long vector consisting of temporal changes of all frequency components of the received signal. The permutation-free ICA, however, only yields a common separation matrix for all frequency bins. So, the separation matrix obtained in the permutation-free ICA has a common directivity pattern for all frequency bins, though the method can avoid the permutation problem. Proposed in this paper is a scheme of multibin ICA that deconvolves mixed signals into original source signals by shifting piecewise integration of a set of frequency bins consisting of the frequency bin in concern and neighboring frequency bins. The proposed method can yield nearly optimal directivity in the form of the separation matrix for each frequency bin, avoiding the permutation problem. Performance of multibin ICA is compared with those of conventional frequency-domain ICA and permutation-free ICA employing segmental SNR as an evaluation index. [Work supported by Knowledge Cluster Project, MEXT, and by Academic Frontier Project Doshisha University.]
Acoustic seaglider
Authors: Howe Bruce M.
Published: October 2013

Continually improving acoustics measurements in the ocean is a sine qua non for the advancement of ocean acoustics and related fields. Acoustic sensors on mobile platforms will enable basic research topics on temporal and spatial coherence and the description of ambient noise, with direct impact on the applicability of coherent processing with its associated gain to signal detection and acoustic navigation and communications within the context of distributed undersea sensor networks. We describe the integration of acoustic receiving and communication capability in gliders with results from several recent field tests. [Work supported by the ONR.]
Synthetic stationary array processing for a towed array in maneuver
Authors: Lee Yung , Lee William , Lee Andrew
Published: October 2013

When long towed arrays undergo significant maneuvering, the array shape rapidly changes within a processing interval that degrades the array beamforming performance. Towed arrays are known to behave much like pulleys through the water. Thus, hydrophones on the towed array will closely follow the motion of the towed point through the water with a time lag relative to the towing speed. From this concept, it follows that, given an appropriate time alignment, a signal snapshot from the rear section of the array can be interpreted as a signal snapshot from the front section of the array at a later time. This synthetic stationary array processing (SSAP) divides the physical array into highly overlapping sequential segments and, using these segments, forms time-lagged snapshots of a stationary array. As a result, this synthetic stationary array has a reduced size and shape that is defined by the first array segment at the beginning of a processing interval. To demonstrate the effectiveness of this process, real towed array data collected from the MAPEX 2000 experiment conducted by SCALANTCEN were processed. The SSAP results successfully demonstrate processing improvements through turns. A few selected signal tracks were simulated to validate the performance of the SSAP processing.
Fiber optic interferometric hydrophone based on fiber Bragg grating with polarization diversity receiver
Authors: Okawara Chiaki , Saijyou Kenji
Published: October 2013

The objective of this work is to overcome polarization-induced signal fading (PSF) that occurs in fiber optic interferometric hydrophones based on fiber Bragg grating (FBG). The use of FBGs as reflectors in fiber optic interferometric hydrophones would greatly simplify the construction of the devices’ wet-end portion by eliminating couplers, joints, and other connections that are required for other types of fiber optic interferometric hydrophones. Unfortunately, the visibility of the interference signal is reduced by PSF, and the demodulated signal is contaminated greatly by the phase noise. A polarization diversity receiver (PDR) is therefore applied to reduce the PSF influence. We developed a prototype of fiber optic interferometric hydrophone based on FBG with the PDR and demodulate an acoustic signal to confirm the effectiveness of the PDR application. Experimental results described here show that the phase noise is suppressed by selecting an optimum port that has high visibility. Consequently, the effectiveness of the application of the PDR is confirmed.
Design of public address system for emergency evacuation in a tunnel
Authors: Yokoyama Sakae , Tachibana Hideki , Sakamoto Shinichi , Tazawa Seiya
Published: October 2013

As a means to improve speech intelligibility of a public address PA system for emergency evacuation announcement in a tunnel, the authors have been investigating the application of the successive time-delay technique and have performed the experiments in an actual tunnel. In the experiments, the effect of the technique has been examined by comparing the difference of speech intelligibility between the conditions with/without time delay. For the design of the PA system in a reverberant tunnel, four kinds of psycho-acoustical experiments on speech intelligibility were performed in an anechoic room using the six-channel recording/reproduction technique and the following results have been obtained: (1) the successive time-delay technique is very effective to improve the speech intelligibility in a tunnel, (2) the system is considerably robust against the error in the delay time, (3) the speech intelligibility improves with the increase of the speech-rate but it should be suitable for such a tense situation as fire emergency, and (4) in order to further improve the speech intelligibility, it is necessary to control the reverberation in the tunnel by any sound absorption treatment. In this paper, the outline of the field experiment and the results of subjective experiments are introduced.
Recent advances in the fish auditory efferent system
Authors: Lu Zhongmin , Tomchik Seth
Published: October 2013

The octavolateral efferent neurons in fish project axons to innervate the ear and lateral line organs. However, the function of the octavolateral efferent system is not well understood. This review focuses on recent progress in structure and function of octavolateral efferent system in a teleost, the sleeper goby (Dormitator latifrons). The sleeper goby has a single octavolateral efferent nucleus that is composed of about 19 large, densely packed somata in the medulla. Most efferent neurons have bilateral dendrites and single axons innervating ipsilateral peripheral octavolateral organs. The efferent neurons have distinctive characteristics of frequency, temporal, directional, and dynamic responses, which differ from those of otolithic organ afferents. How efferent stimulation affects afferent response is investigated by electrically stimulating efferent somata and recording compound action potentials from afferents innervating the saccule, the main auditory organ in this species. There are different efferent modulatory effects on afferent response, depending on the level of background noise. Efferent activation inhibits afferent response in quiet conditions but can enhance signal detection in noisy environments. Results of these studies indicate that the fundamental role in efferent modulation of afferent input is likely conserved in both nonmammalian vertebrates and mammals. [Work supported by NIH/NIDCD Grant R01DC003275.]
Fish population and behavior revealed by instantaneous continental-shelf scale imaging
Authors: Makris Nicholas C. , Ratilal Purnima , Symonds Deanelle T. , Jagannathan Srinivasan , Lee Sunwoong , Nero Redwood W.
Published: October 2013

Fish populations in continental shelf environments are instantaneously imaged over thousands of square kilometers and continuously monitored by a remote sensing technique in which the ocean acts as an acoustic waveguide [Science 311, 660–663 (2006)]. The technique, ocean acoustic waveguide remote sensing (OAWRS), has revealed the instantaneous horizontal structural characteristics and volatile short-term behavior of very large fish shoals, containing tens of millions of fish and stretching for many kilometers. The former follows a fractal or power-law spectral process, indicative of structural similarity at all scales. The latter features compressional waves of fish population density that travel roughly an order of magnitude faster than fish can swim. Here we present an overview of OAWRS imagery documenting fish activity over a 2-week period in the Spring of 2003 at the edge of the continental shelf, roughly 200 km south of Long Island, NY. Until now, continental shelf environments have been monitored with highly localized line-transect methods from slow-moving research vessels. These methods significantly undersample fish populations in time and space, leaving an incomplete and ambiguous record of abundance and behavior.
Simultaneous observations of zooplankton distribution and density using net sampling, a laser-optical plankton counter, and acoustics
Authors: Mukai Tohru , Fujimori Yasuzumi , Kishi Jun-ichiro , Iida Kohji
Published: October 2013

Conventional plankton sampling methods are based on net tows, which are often poorly suited to capturing spatiotemporal variability. Various automatic plankton samplers based on optical principles have been developed recently. The laser-optical plankton counter (LOPC) was developed as the next generation OPC. In addition, acoustic technology has been used extensively to survey zooplankton distribution and abundance. This study compared the density and size spectra determined using net contents, LOPC data, and acoustic data. Surveys were conducted for 3 years around Hokkaido, Japan. The sound-scattering layer (SSL) was recorded on the echogram of an echosounder. Biological sampling was conducted using a 1-m2 frame-type mid-water trawl (FMT; mesh size 1.5 mm) and a NORPAC net (mesh size 500 microns). An LOPC was mounted inside the mouth of these nets. Net sampling was carried out at dusk, when the SSL moves toward the surface (ca. 10–35 m). Acoustic data were derived using a Simrad EK60 echosounder operating at 38, 120, and 200 kHz simultaneously. A comparison of the use of acoustic data, LOPC data, and net contents to assess zooplankton distribution and density will be presented and discussed. [Work supported by JSPS Grants-In-Aid for Scientific Research.]
Acoustic and optic characterization of forage fish distribution in the Bering Sea
Authors: Parker Stetter Sandra , Horne John , Churnside James
Published: October 2013

Mesopelagic forage fish species are important components of the Bering Sea ecosystem, but information on species distribution and identity is limited. Using acoustics and optics [LIght Detection And Ranging (LIDAR)], this study compared distribution patterns detected by the two gears. Forage species distribution and quantity differed between shelf (6–100 m) and slope (6–100 m, 100–300 m, 300 m to bottom) regions. Acoustic results suggested that shallow and deep depth zones contained dispersed backscatter while the middle slope layer contained patchy schools associated with the shelf break. Variogram results for repeated LIDAR surveys of the shelf and slope regions indicated that backscatter distribution between 6 and 30 m was dynamic at the scale of days. This result was expected given the strong frontal nature of the area. When LIDAR results were compared with coincident acoustic transects on the shelf and slope, differences were found in gear detection of backscatter. Based on acoustic results, 25%–63% of forage fish in the shelf and slope regions were deeper than the LIDAR detection range. Although both LIDAR and acoustics are constrained to portions of the water column, the utility of remote sampling technologies is dependent on survey objectives. [Funding was provided by the North Pacific Research Board.]
Estimating pressure gradients governing fish shoal dynamics over continental-shelf scales
Authors: Jagannathan Srinivasan , Lee Sunwoong , Symonds Deanelle T. , Ratilal Purnima , Makris Nicholas C.
Published: October 2013

The environmental pressure gradient and stress field on fish shoals spanning more than 10 km is calculated from a sequence of instantaneous continental-shelf scale OAWRS images of areal fish population density [Science 311, 660–663 (2006)]. The calculation is based on continuum mechanics and the velocity field of fish groups previously estimated from OAWRS imagery using acoustic flow [Jagannathan et al., J. Acoust. Soc. Am. 119, 3435 (2006)]. These environmental stress fields describe the driving mechanism behind the dynamic behavior of large fish groups such as expansion, contraction, and translation. Regions of high stress are correlated with regions of high areal fish density. They are also correlated with density waves that convey information across a fish group. Our estimates of environmental stress on fish groups can be correlated with environmetal parameters such as plankton, temperature, and current distributions through physical and biological driving mechanisms.
Sonar mapping for coral reef conservation
Authors: Zurk Lisa , Lotz Joe , Ellis Tim , McNames James , Ecochard Jean-Louis
Published: October 2013

Many conservation efforts require an inexpensive and easy-to-use method of mapping and monitoring coral reef structure. A desirable product is a 3D map that effectively portrays the reef relief (and potentially the sub-structure) or features such as fish locations and fish spawning areas. Given field site limitations associated with the reefs, the mapping technique should be portable, rugged, and easy to use. One solution, developed at the Nature Conservancy (TNC), is to utilize a Lowrance fish finding sonar with a GPS system to estimate the top of the coral. This approach has been employed for TNC mapping exercises to generate ArcGIS maps of conservation areas. However, these maps are often negatively affected by sampling and processing artifacts such as sparse collection geometries (causing interpolation errors), distortion due to beam shape, and changes in boat (transducer) position due to wave motion. In this presentation we discuss recent work to address these effects, as well as enhancements to the system by processing acoustic returns from the coral substructure or within the water column for detection of fish populations. The presentation will provide a description of future research, including the intent of making the finished system available as a conservation tool.
A partial theory of phase coherence loss in deep ocean propagation
Authors: Beron-Vera Francisco J. , Brown Michael G.
Published: October 2013

In a fluctuating ocean, coherently adding multiple receptions of repeated transmissions of a signal generally results in a processing gain relative to the background noise only for some finite duration owing to a gradual loss of wave-field phase coherence. In this talk a theoretical framework for understanding some elements of phase coherence loss in transient wave fields in deep ocean environments is presented. The theory predicts that phase coherence loss is pathdependent and very different at short range than at long range. PE simulations of transient wave-field phase coherence loss in an idealized time-varying ocean are presented and shown to be in good qualitative agreement with theoretical predictions. [Work supported by ONR.]
A multistation coastal acoustic tomography system with coherent operation
Authors: Zheng Hong , Kaneko Arata , Gohda Noriaki
Published: October 2013

A multistation coastal ocean acoustic tomography (CAT) system with coherent operation has been developed and applied to field experiments over ten times in the last 8 years. The system is designed to measure both temperature and current velocity fields in the coastal ocean. As is well known, an ocean acoustic tomography is generally based on travel time measurements. In the CAT system, the clock accuracy for travel time measurement is most important to realize coherent transmission from multistations and to measure especially current velocity. For highly accurate coherent transmission from multistations, each station is equipped with a timing module synchronized by the clock signals of global positioning system (GPS). As a result, time error is maintained less than 0.1 μs. In the sound transmission from multistations, the code division multiple access (CDMA) and spread spectrum technology are applied. The coded signals also improved remarkably the signal-to-noise ratio of the CAT system. With detecting not only the amplitude, but also the phase of received signals, the accuracy of travel time measurement is improved within a sampling interval of data. This multistation CAT system served to map 2-D time-varying tidal current structures in Tokyo Bay (Kaneko et al., 2005).
Various old and new shock-wave applications require different shock-wave beam characteristics
Authors: Schultheiss Reiner
Published: October 2013

Four different medical applications of shock waves and the appropriate pressure field will be discussed. Lithotripsy requires maximum shock-wave energy at the stone. High-pressure amplitudes and the total acoustical energy are the preferable parameters discussed for the disintegration effect. Improved kidney stone disintegration coincident with reduced side effect on the nephritic tissue was realized by a low-angle focusing ellipsoid (LithoGold). In the treatment of soft tissue, unfocused shock waves allow the mechanical parameters like peak pressure and the energy density to be lowered dramatically. Activation of the body’s healing mechanisms are found after low pressure/ energy application by the release of growth factors, increased number of blood vessels, and the formation of new true tissue instead of scar tissue. For the treatment of diabetic skin ulcers an unfocused shock head is in controlled clinical studies within the USA. The last application relates to treating open heart muscle and requires a very small shock-wave head. A very short focal distance (11 mm) is used. New blood vessels and the formation of new heart muscle cells are found after treatment. Technical and medical reasons for the different shock-wave beam characteristics are provided.
Influence of focusing and signal shape on the efficiency of stone fragmentation in vitro under equal energy conditions
Authors: Riedlinger Rainer E. , Liebler Marko , Dreyer Thomas
Published: October 2013

To investigate the mechanisms of fragmentation in lithotripsy, simulations and experiments were performed. Wave shapes deduced from measurements near the focus of a piezoelectric source were used as input signals for finite element calculations of stresses and strains in spherical stones of different sizes. The effects of strongly and weakly focused sound fields were compared to those of a plane wave assumption representing lithotripters with large focal widths. The energies of the fields were matched. In targets with diameters less than 6 mm the simulated tensile stresses induced by strong and weak focusing exceed those of the plane wave assumption. For in vitro experiments a double-layered self-focusing piezoelectric source was used. To represent lithotripters with different sound fields the signal shape was varied by changing the interpulse delay but maintaining the energy. The total number of pulses needed for fragmentation into particles smaller than 2 mm diameter was counted. At usually applied energies experimental results show that the numbers of pulses needed for complete fragmentation are almost independent of the signal shape. In conclusion, the results indicate that strongly focused lithotripters are in principle more effective than those with wide focal widths in breakage of small stones.
Using shock waves and micro-nanostructures for gene and drug delivery
Authors: Kendall Mark
Published: October 2013

Efficiently and safely delivering biomolecules to the skin’s immunologically sensitive cells holds the promise of advancing radical new drugs, vaccines, and immunotherapies for major diseases [D. Chen et al., Expert Rev Vaccines 1(3): 89–100 (2002)]. Here I present research into using shock waves and micro-nanostructures to meet this goal. First, I analyze the physiology and immunology of the skin target and then introduce current physical approaches for targeting these cells for the immunotherapy [M. A. F. Kendall, Vaccine May 22; 24(21): 4651–656 (2006)]. Then, I focus on biolistics—accelerating with a helium flow micro-particles coated in DNA to ballistically penetrate the human skin in order to achieve an immunological effect [M.A.F. Kendall, Shock Waves J., 12(1), 22–30 (2002)]. I present key findings on the engineering of these devices, skin physical interactions induced by micro-particle impact and the resultant local biological responses. Finally, I introduce a micro-nanoprojection array patch technology, highlighting key advantages over biolistics, including the prevention of cell-death from shock impact with key cells.
Numerical study of the collapse of a bubble subjected to a lithotripter pulse
Authors: Johnsen Eric , Colonius Tim
Published: October 2013

In shock wave lithotripsy, the combined effect of focused shock waves and cavitation pulverizes kidney stones. Although cavitation has been shown to play an important role in the stone comminution process, the underlying mechanism has yet to be fully understood. The goal of the present study is to quantify the potential damage caused by the collapse of a single bubble near a solid surface. Using a high-order accurate quasiconservative, shock- and interface-capturing scheme [E. Johnsen and T. Colonius, J. Comput. Phys., in press (2006)], the response of an air bubble subjected to a lithotripter pulse is considered. In particular, quantities important in cavitation erosion, such as wall stresses and reentrant jet velocity, are measured as functions of the properties of the pulse (amplitude, wavelength) and the geometry of the problem (stand-off distance from the wall, presence of neighboring bubbles). Preliminary two-dimensional results for a ‘‘cylindrical bubble’’ show that a large water-hammer pressure is measured along the wall. This pressure increases for smaller stand-off distances and longer wavelengths. Further results for spherical bubbles will be presented at the meeting. [This work was supported by NIH Grant PO1 DK043881.]
Shock-wave-based biolistic apparatus
Authors: Menezes Viren , Hosseini S. H. R. , Takayama Kazuyoshi , Nakada Mutsumi , Kanno Akira
Published: October 2013

A shock-wave-based biolistic device has been developed to deliver DNA/drug-coated micro-projectiles into soft living targets. The device consists of an Nd:yttrium aluminum garnet laser, equipped with a suitable optical setup and a thin aluminum (Al) foil (typically 100-μm thick). The powdered vaccines to be delivered are deposited on the anterior surface of the foil and the posterior surface of the foil is ablated using the laser beam. The ablation launches a shock wave through the foil that imparts an impulse to the foil surface, due to which the deposited particles accelerate to high velocities that are sufficient to enable them to penetrate soft targets. The device has been tested for in vivo DNA delivery by delivering plasmid-coated, 1-μm size, gold (Au) particles into onion and tobacco cells. The GUS activity was detected in the onion and tobacco cells after the addition of an artificial substrate. The present device is totally nonintrusive in nature and has a potential to get miniaturized to suit the existing medical procedures for drug delivery.
Traveling wave power in an energy circulation surface acoustic wave motor stator
Authors: Kurosawa Minoru , Miyazaki Yoshito , Shigematsu Takashi
Published: October 2013

Surface acoustic wave (SAW) motors have been demonstrated their high performance as micro linear motor in speed, thrust, fine stepping motion, and so on. For application of the SAW motor to some equipment, however, the power consumption will be a problem in spite of the superior performance due to the limited power resource of a system. To avoid the large power consumption, an energy circulation driving method has been proposed and tested. The circulation factor will be discussed as concerns the performance at the energy circulation electrode and the phase shift in the system. For example, in case of the 90% circulation coefficient at the circulation electrode, eight times power of the driving power circulates as a traveling wave. But the 45 deg phase shift causes a reduction of one-fourth of the traveling wave. The energy circulation of the SAW motor will be discussed quantitatively. [Research was supported by the Ministry of Education, Culture, Sports, Science and Technology, Grant-in-Aid for Science Research.]
An ultrasonic linear motor using traveling waves of twin ridge
Authors: Koyama Osamu , Koyama Daisuke , Nakamura Kentaro , Ueha Sadayuki
Published: October 2013

An ultrasonic linear motor using ridge-mode traveling waves on a substrate is proposed for precision positioning. In our experiments, two parallel ridges are machined on an alumina ceramic substrate with the spacing of 19 mm. The width, height, and length of the ridge are 3 mm, 9 mm, and 186 mm, respectively. Two piezoelectric elements, 19 mm in length and 5×5 mm2 in cross section, were installed at the position of 15 mm from each end of the ridge, and excited at 87.136 kHz in their fundamental longitudinal mode to stimulate the fundamental ridge mode. Elliptical particle motions are formed, due to traveling waves along the ridge waveguides by the phased drive of the two transducers. An alumina ceramic slider pressed to the two waveguides is moved at 13 mm/s in the opposite direction to the traveling wave through the friction forces. The moving direction can be switched by changing the propagation direction of the traveling wave. The detailed characteristics are experimentally studied.
Phased arrays and devices for high-intensity focused ultrasound
Authors: Clement Greg T.
Published: October 2013

Focused ultrasound (FUS) is rapidly attracting attention as an alternative to surgery for the treatment of tumors and other disorders. Such therapeutic procedures were first proposed over 60 years ago, but have only recently become clinically feasible. These new successes can be attributed primarily to two advances: improvement in noninvasive monitoring techniques and the development of high-power ultrasound arrays. As the field progresses, there is a demand for increased transducer bandwidth, allowing tissue-specific frequency optimization, and even imaging, while maintaining high acoustic power outputs. These arrays have been made possible via dice-and-fill manufactured 1-3 piezocomposite arrays. Transducers with over 500 elements have been tested in the clinic, and designs have been proposed for at least 5000 elements. Meanwhile, the rapid development of high-power, broadband IC technology has made it possible to build electronic components for amplifiers and switching at a practical cost (under $50/channel). This talk will present several devices being developed in the Harvard/BWH FUS lab, in conjunction with the newly formed National Center for Image Guided Therapy. The challenges and limitations of operating at high driving intensities will also be addressed, with particular attention to nonlinear restoring behaviors of arrays driven off-resonance. [Work supported by NIH Grant U41 RR019703.]
Study of a micro-tactile sensor with longitudinal vibrator in a smart micro-ultrasonic scalpel
Authors: Uchikawa Shunsuke , Kurosawa Minoru K.
Published: October 2013

A smart micro-ultrasonic scalpel using a hydrothermal PZT film vibrator has been proposed and fabricated. The micro-scalpel has two functions: in addition to a micro-ultrasonic scalpel, a micro-tactile sensor to indentify tumors. The tactile sensor function is studied. The resonance frequency of the vibrator changed when the vibrator tip made contact with a rubber sample. Irrespective of compliance of the sample, the resonance frequency increased up till about tens of micrometer sample. Then, against further sample deformation by the tip, the resonance frequency decreased. From the theoretical analysis using mechanical contact modeling [K. L. Johnson, Contact Mechanics (Cambridge University Press, Cambridge, 1985], it was found that the resonance frequency drop was caused by increase of the damping effect of the sample due to deeper stick of the vibrator tip. The Young’s modulus of samples is able to be estimated from the resonance frequency curve. From the experimental result, there was a difference in the resonance frequency between a soft rubber sample and a hard one. The elastic characteristic of the sample will be quantified.
Introduction of sound material in living environment 2004 (SMILE 2004): A sound source database for educational and practical purposes
Authors: Kawai Keiji , Fujimoto Kazutoshi , Iwase Teruo , Sakuma Tetsuya , Hidaka Yoshito , Yasuoka Hirohito
Published: October 2013

Sound sources are used in various settings of education, research, and business that are related to architectural acoustics. Especially in educational scenarios, they are very effective for students to learn theories together with the experience of listening to actual sounds related to them. Sound Material In Living Environment (SMILE 2004), a sound source database published in 2004 in DVD form (Japanese only), is the culmination of our project. SMILE 2004 is intended as a collection of sample sounds for use in lectures on architectural acoustics at universities or industrial high schools. In addition, it is useful for measurements or demonstrations for academic or practical purposes. The database contains 913 digital sound files of real sounds and impulse responses, which cover the study fields of acoustics, noise control, and soundscapes. Each sound is accompanied by such information as the 1/1 octave band sound pressure levels and a brief explanation and photographs of the situation in which the sound was recorded. In addition, sample presentations for lectures and practical demonstrations are attached as examples of the use of this database for educational and practical purposes. Details of all the above features will be introduced in a demonstration.
The multimedia simulator of radiation sound field created by a vibration disc
Authors: Michigami Kohei , Masuda Takahiro , Suda Hiroshi , Miida Yoshiro
Published: October 2013

In the field of acoustic education, acoustic phenomena are represented in textbooks as sound models and complex numerical formulas. For that reason, it is difficult for students to visualize, intuitively, the relations between acoustic phenomena and complex numerical formulas. Sufficient understanding was not obtained using static teaching materials, such as sentences and figures in textbooks and notes on a blackboard. Therefore, we have produced multimedia teaching materials that render difficult phenomena as interactively visible. The multimedia teaching materials that have been produced comprise explanatory slides, relation movies, and simulator teaching materials. They show a radiation sound field created by a vibrating disc simulator. It is necessary to calculate many complex series to compute the sound field. Then, the sound field is changed complexly and remarkably by wavelength. Therefore, it is a difficult field to understand for students. Our multimedia teaching material expresses it using 3D-CG. Students can see details of the sound-field changing perspective and the wavelength and disc size ratio. Moreover, students can use it to verify the sound pressure level of a graphically selected point, just as with a measuring instrument.
Tools for speech perception, production, and training studies: Web-based second language training system, and a speech resynthesis system
Authors: Akahane-Yamada Reiko , Adachi Takahiro , Kawahara Hideki
Published: October 2013

We describe a Web-based instruction system for second language (L2) learners, dubbed ATR CALL. This system is a collection of speech perception, production, and comprehension training tools, designed to examine L2 acquisition mechanisms, especially for native speakers of Japanese who are learning English as L2. Each training component focuses on the acoustic-phonetic, prosodic, lexical, or semantic decoding level of spoken language. The stimuli are selected and presented from a large speech database of 13000 English words and 6000 English sentences. In the pronunciation training component, learners’ productions are scored using HMM-based evaluation algorithms, and automatic and immediate feedback about pronunciation goodness is provided. Speech analysis tools for language learners are also provided. We also describe a speech manipulation system, dubbed STRAIGHT [Kawahara et al., Speech Commun. (1999)]. This system resynthesizes stimuli with quality as high as the original stimulus even after manipulating multiple parameters. A speech morphing algorithm on this system enables us to manipulate various features independently [Kawahara et al., ICCASP 2003]. Thus, it generates stimulus continuum varying in supra-segmental domain and/or segmental domain. [Work supported by JSPS, and e-Society by MEXT.]
Vowel synthesis tool based on transmission line model as a web application
Authors: Ogata Kohichi , Masuya Takuro , Shin Yuichiro
Published: October 2013

This paper introduces a web application for vowel synthesis in acoustics education. Synthesis systems that provide users with interactive operation for determining vocal tract configuration and vocal fold control parameters can be effective tools for intuitive understanding of vowel production for students. For example, differences in the size of the vocal tract and vocal folds between male and female speakers can be recognized as differences in formant and pitch frequencies in speech sounds. The realization of such a system as a web application is suitable for platform independent use, considering the recent progress in information and communication technology. In our developed system, interactive operation for determining vocal tract configuration and vocal fold control parameters is achieved on a web browser by using a Java applet. These articulatory parameters are transferred to a server computer via a client/server connection using socket programming, and synthetic speech is produced using calculation programs on the server computer. The speech synthesizer installed on the server is based on the hybrid speech production model proposed by Sondhi and Schroeter. A preliminary user test showed that the system demonstrated a certain applicability as a teaching tool.
Amazing features of the auditory system
Authors: Ashihara Kaoru , Iwaya Yukio , Ohgushi Kengo , Nakajima Yoshitaka
Published: October 2013

Some audio and audiovisual demonstrations will be presented in order to review the unique nature of the auditory system. The demonstrations cover a wide range of topics: the gap transfer illusion, combination tone, interaction between auditory and visual information, and binaural recording and reproduction. The phenomena to be presented are closely related to the key features of hearing, such as the auditory scene analysis, speech perception, perception of the spatial information, and interaction with other modalities. Because these demonstrations are not only attractive but also of some scientific importance, they can be used as teaching materials in education of physics, physiology, psychology, and engineering. Studying these phenomena will give us insights into the functions of the peripheral and central auditory system.
Demonstration of wave synthesis and spectral analysis
Authors: Hansen Uwe J.
Published: October 2013

Many inexpensive keyboard synthesizers include a flute sound with overtone levels about 30 dB below the fundamental. Since these wave shapes are nearly perfect sine waves, they are ideally suited to introduce the concept of complex tone synthesis by adding harmonics. Such a keyboard will be available at the station for demonstration purposes and for viewer experimentation. Complex tone synthesis using amplitude control in a Cool-edit program will also be available.
Animations, visualizations, and auralizations in architectural acoustics
Authors: Muehleisen Ralph T.
Published: October 2013

A number of animations, visualizations, and auralizations developed for use in architectural acoustics classes are presented. Animations of plane waves, spherical waves, and standing waves were created using MATLAB software. Visualizations of modes in regular and arbitrary shaped enclosures were created in Comsol Multiphysics software. Auralizations of tonal and broadband noise, hearing loss, transmission loss, and classroom acoustics were created using Adobe Audition software.
Sonification of sound: Auditory display for acoustics education
Authors: Cabrera Densil , Ferguson Sam , Maria Robert
Published: October 2013

Sonification is concerned with data representation to the ear using nonspeech audio. While auralization is routinely used in architectural acoustics, the broader processes encompassed by sonification are not so commonly applied, but can enhance the appreciation of acoustical properties of materials and structures, audio signals, and acoustic system measurements. We present examples of sonifications such as (i) auditory graphs of reflection and transmission coefficients and reverberation times; (ii) auditory graphs of percentiles and moments, applied to time-varying sound levels and to magnitude spectra; (iii) conditioning of room impulse responses for sonification using techniques such as time stretching, signal reversal, filtering and auto-convolution/correlation; (iv) sonification of complex frequency response or signal spectra; and (v) applications of the Hilbert transform for audio signal sonification. Compared to graphic or numeric representation, such sonifications have the advantage of providing an aural experience of the aspect of sound that is sonified, and so directly convey to a listener something of the meaning of the data.
Application of speech recognition to teaching English as a foreign language
Authors: Obari Hiroyuki , Kojima Hiroaki , Oomura Hiroshi , Okumura Machi
Published: October 2013

English is considered to be an important common international language; therefore, in Japan English education plays an important role to make Japanese speakers of English intelligible enough to be properly understood for international communication. Intonation and the rhythm of the language and pronunciation of each word are crucial to comprehensive speech. So far the CALL system has not been well equipped with effective software for improving pronunciation. This is why PRONTEST and AIST (National Institute of Advanced Industrial Sciences and Technology) have been jointly developing special software for teaching English pronunciation using the technology of Speech Recognition System integrated into the CALL system. This software can automatically correct the crucial pronunciation of lower Japanese EFL learners and teach them how to improve its pronunciation with a good piece of advice after they pronounce several words with the computer. So far we have successfully developed the CALL system, in which we can deal with the following sounds: [r] [l] [s] [sh] [th] [z] [f] [v] [d] [b]. We carried out an experiment and found out that about 90% of the students were satisfied with correcting their pronunciation using this software at Aoyama Gakuin University.
Acoustics of Eastern and Western bells, gongs, and drums
Authors: Rossing Thomas
Published: October 2013

Bells, gongs, and drums have been part of most Eastern and Western cultures throughout history. We compare the acoustics of some examples of these types of percussion instruments, both contemporary and historical.
Tunings of historical Korean pyeongyeong and pyeonjong
Authors: Yoo Junehee , Jin Suyoung , Kim Hyunsoo , Sung Koeng-mo , Noh Junguk , Ko Hyun-woo
Published: October 2013

In order to reconstruct the whangjongeum or scale in Korean traditional instruments, we have measured frequencies of historical pyeongyeong stones and pyeonjong bells mainly from the 14th to 19th centuries. Pyeongyeong consists of 16 chime stones tuned to a scale quite similar to the Western scale beginning with C4. Pyeongjong consists of 16 chime bells, tuned approximately an octave lower than pyeongyeong. We present frequency averages and standard deviations for 124 chime stones and 64 chime bells available in the National Center for Korean Traditional Performing Arts. The spread in frequencies appears to be greater in some periods in history than in others, but the average frequency is quite consistent.
Ballistic range simulation of sonic boom generation
Authors: Takayama Kazuyoshi , Sun Ming-Yu , Kikuchi Takamasa
Published: October 2013

A result of recent ballistic range experiments applied to a sonic boom simulation is reported. For flight simulations at transonic speed ranging from 340 to 400 m/s, we used a 51-mm bore gas gun launching 51-mm-diam sabot and projectile combinations, and for supersonic flight simulations exceeding 400 m/s we used a 15-mm bore two-stage light gas gun. Flow diagnostics were performed mainly by double-exposure holographic interferometry, shadowgraph recorded with a high-speed video camera, and pressure measurements. The present experimental setup is so versatile that we placed a water basin on the recovery tank floor and measured interactions between sonic booms and wavelets in the water basin. As one of the basic research topics related between shock dynamics and aeronautics, we launched 40-mm-diam spheres at high transonic speed of shock Mach number ranging from 1.01 to 1.i at increments of every 0.01, visualized quantitatively flows over spheres, and could determine shock standoff distances over spheres. The speed range we simulated is in the region hardly achievable in existing wind tunnels.
Atmospheric turbulence filter functions derived from high-fidelity measurements
Authors: Locey Lance , Sparrow Victor
Published: October 2013

Efforts have been underway to develop filter functions suitable for adding turbulent atmospheric effects to theoretical low-boom waveforms. Filter functions have been created based on a measured input-output relationship. The input is a relatively clean sonic boom waveform measured at altitude by a glider, and the outputs are turbulized’ waveforms measured on the ground. One input waveform and multiple output waveforms are used to represent multiple realizations of the atmosphere. Work presented in 2005 [Locey and Sparrow, Innovations in Nonlinear Acoustics, 17th International Symposium on Nonlinear Acoustics (American Institute of Physics, Melville, NY, 2006)] yielded an initial set of filter functions using one particular algorithm and data collected during the Shaped Sonic Boom Experiment (SSBE) in January of 2004. In this talk new results will be presented based on high-fidelity measurements made at NASA Dryden Flight Research Center in June of 2006 [T. Gabrielson et al., Proc. Internoise (2006)]. Time permitting, additional methods for obtaining filter functions will be discussed, including the use of existing sonic boom propagation codes modified to include atmospheric turbulence. [Work supported by the FAA/NASA/Transport-Canada PARTNER Center of Excellence for Aircraft Noise and Aviation Emissions Mitigation.]
Extension of a sonic boom model to ellipsoidal Earth and 3-D atmosphere
Authors: Plotkin Kenneth J. , Haering Edward A.
Published: October 2013

Sonic boom ray tracing models generally use flat-earth geometry, with 3-D ray propagation through a horizontally stratified atmosphere. There has been recent interest in long-range sonic boom propagation, both for analysis of sonic boom carpet edges from high-altitude flight and for analysis of over-the-top booms. The sonic boom program PCBoom4 has been extended to incorporate ellipsoidal earth and full 3-D ray tracing through a three-dimensional atmosphere. Ellipsoidal geometry of the Earth is handled by the method of Sofair [J. Guidance Control, 23(2)], which defines a local vertical at given coordinates. A tangent reference plane is defined, and ray tracing is performed using the 3-D formulation of Schulten [NLR TP 97-374], in Cartesian coordinates. Once rays are traced, ray tube areas, signature aging, and focal zones are computed in the traditional manner. When over the top booms are analyzed, a starting signature for propagation after the caustic passage is generated from the recent numeric calculations by Kandil [AIAA Paper No. 2005-0013]. The new program, denoted PCBoom5, is expected to be available in 2007.