bluuebunny/crossref_metadata_2025 huggingface dataset:
Year-round changes of ambient noise in freshwater habitats and temperature effects on hearing in fishes
Authors: Amoser Sonja , Ladich Friedrich
Published: October 2013

Fish get crucial information for their survival from their acoustic environment. Therefore, changes in ambient noise as well as temperature over the year potentially impose great challenges for fishes, especially in freshwater habitats in temperate climates. Noise levels vary more in stagnant habitats such as lakes, backwaters, and streams than in large rivers. The spectral profiles change in stagnant habitats due to biotic noise sources in summer (e.g., stridulating insects), whereas in small streams spectral composition differs due to small changes in water volume, e.g., after snow melt. To investigate possible seasonal effects on fishes, we studied the hearing capabilities of a hearing specialist (Common carp) and a hearing nonspecialist (European perch) at two different temperatures (12°C and 22°C) using the AEP recording technique. In the carp the hearing sensitivity decreased up to 12 dB (mean decrease: 4 dB) at 12°C, whereas no such change was observed in the perch. Latencies of auditory evoked potentials became longer by approximately 0.8 ms at lower temperatures in the carp. The results indicate that auditory sensitivity in hearing specialists is affected by changes in temperature as well as ambient noise throughout the year. [Work supported by FWF.]
The influence of ambient temperature and thermal acclimation on hearing in an eurythermal hearing specialized fish
Authors: Wysocki Lidia E. , Popper Arthur N.
Published: October 2013

Many fish species live in habitats whose water temperature underlies seasonal and diurnal fluctuations. Being ectothermic animals, their body temperature depends on the temperature of the ambient water. Since the speed of all metabolic processes depends on body temperature, the ambient temperature might affect various physiological processes including all sensory systems. However, the maintenance of sensory functions in a changing environment can be crucial for an animal’s survival. Several fish species strongly rely on their auditory abilities for acoustic orientation, communication, detecting predators and prey, and finding mates. Channel catfish (Ictalurus punctatus) was chosen as a model for an eurytherm species with a relatively high hearing sensitivity and bandwidth to investigate the influence of ambient temperature and thermal acclimation on the auditory system. Hearing sensitivity was measured at different water temperatures to which the animals were either unacclimated or acclimated by recording auditory-evoked potentials. The ambient water temperature significantly influenced hearing thresholds and the shape of the auditory-evoked potentials, especially at higher frequencies. Hearing sensitivity remained decreased at low water temperatures even after an acclimation period of one month, indicating that certain physical limits on sensory processes cannot be compensated for by thermal acclimation.
Flows near model otoliths and their implications for fish hearing
Authors: Kotas Charlotte W. , Rogers Peter H. , Yoda Minami
Published: October 2013

The fish inner ear contains a dense, bony otolith that oscillates in response to acoustic excitation. This relative motion between the otolith and its surrounding fluid generates both steady streaming and unsteady flows in the fluid which in turn displaces the hair cells on the macular membrane. Fish ‘‘hear’’ by interpreting these hair cell displacements. However, most of the hair cells are located near a groove along the otolith (the sulcus), making it likely that the irregular geometric features of the otolith will affect how fish hear by influencing the motions of these hair cells. To understand these acoustically induced flows, magnified otolith models were constructed based upon three-dimensional computer tomography scans of actual otoliths. The model otoliths were sinusoidally oscillated so that steady streaming and unsteady flows could be experimentally studied using particle-image velocimetry. The effect of geometric features like the sulcus was studied near the model surface at various oscillation frequencies, ω, and amplitudes, s. Results will be presented for Reynolds number Re≡ωL2/ν≊1–102 and amplitude ratios ε≡s/L=0.05−−0.2, where L is a representative otolith length scale and ν is the kinematic viscosity of the fluid. [Work supported by ONR.]
An overview of the theoretical framework for measuring fish swimming speed by a sector-scanning sonar
Authors: Hamano Akira , Miksis-Olds Jennifer , Jakubiak Christopher , Bernard Ernest
Published: October 2013

Two identical high-frequency sector-scanning sonars, mounted on a stationary acoustical-optical platform (AOP), were used to study the swimming speed of fishes. The first phase of this study consisted of a motion calibration performed in an acoustic test tank using a standard target sphere (WC 38.1 mm). The sonars are a 200-kHz sector-scanning system employing an 8-element array to receive echo signals over a 90° arc. An overview of the theoretical framework for the motion calibration of the sector-scanning sonar is presented. The second phase of the study related the calibration data to the observed movement of fish. The two-dimensional swimming tracks were identified from the digitized sonar data recorded while the AOP was deployed on the seafloor. These tracks were compared with the movement of the target sphere to make estimates of fish swimming speed. Optical data, when available, were used to confirm the results of acoustic data. The limitations and precision of swimming speed measurements using this system are discussed. The application of this methodology to studies of fine-scale fish behavior has the potential to make previously intractable questions possible. [Work supported by NOAA.]
Depth- and size-dependent rhythms of animal emergence in an estuary
Authors: Sato Mei , Jumars Peter A.
Published: October 2013

Among migrating crustaceans, some species inhabiting shallow waters stay very close to the bottom or burrow into the sediments during the day and come up to the surface at night. This behavior, called emergence, was monitored by the Tracor Acoustic Profiling System (TAPS) with six frequencies (265–3000 kHz) to clarify the mechanisms of benthic-pelagic coupling. Instead of one emergence event up to the surface at night, data with high spatial resolution indicate multiple emergence events varying with both the size of the organisms and distance above the bottom, suggesting that for some species there is a target depth beyond which upward migration is limited. In the Damariscotta River estuary, ME, nocturnal emergence events of mysid shrimp, Neomysis americana, occur from late June through early November. Mysid shrimp are known to be important food sources for fishes such as longhorn sculpins, smelt, alewives, and Atlantic cod. The timing of their emergence near the bottom corresponds to the maximum flood tide, suggesting enhancing retention in the estuary. Smaller organisms, on the other hand, emerge primarily during periods of slack tide, but reach the surface only at slack low, also avoiding washout.
Comparing repeated sidescan sonar measurements of benthic squid egg beds in Monterey Bay, CA
Authors: Foote Kenneth G. , Iampietro Pat J. , Young Mary
Published: October 2013

The squid Loligo opalescens lays its eggs in capsules attached to a flat sandy substrate. These capsules are usually clustered in so-called egg beds. Earlier work in Monterey Bay, CA [Foote et al., J. Acoust. Soc. Am. 119, 844–856 (2006)] established the acoustic detectability of such egg beds. This work has now been extended in a new study performed in June 2006. An EdgeTech sidescan sonar was towed at nominal 5-m height over the bottom. Measurements were made at 400 kHz, horizontal beamwidth 0.5 deg, along six parallel transects, with adjacent centerlines separated by 30 m. The swath width along each transect was 100 m. The transects were repeated on 10, 13, and 14 June. Data from areas where egg beds were densely concentrated, confirmed by drop video camera, have been excerpted. Comparisons of corresponding data, which are generally very strong, are quantified. The question is asked as to whether such sidescan sonar data can be used differentially to measure egg-laying success or hatching over rather short periods of time. If so, this could be a useful tool both in ecological studies and for management purposes. [Work supported by NURP.]
Robust analysis of single echo trace obtained by split beam sounder
Authors: Furusawa Masahiko , Amakasu Kazuo
Published: October 2013

The theory and method of the echo trace analysis of single echoes (ETA), which simultaneously analyze the shape and level of single echoes, are almost established. But, the method has not been extensively used. The major reasons are high-quality echoes with a high signal-to-noise ratio (SNR) necessary for the analysis are some times difficult to obtain; the error introduced by transducer motion is large; and conditions for the theory sometimes could not be fulfilled. Therefore, we apply the ETA to the split beam method, which is most advantageous for the ETA, and make the method robust by introducing the following: careful echo selection considering SNR, correction of the effect of transducer motion, smoothing of the trace by regression analyses, introduction of indexes checking reliability, etc. The useful results of our ETA are the track, the swimming speed and orientation, the target strength as a function of tilt angle, and the estimated size of individual fish. The robust ETA was applied to echoes of fish near a sea bottom and of Antarctic krill to confirm the effectiveness of the method.
Vertical structure and arrival times of the axial wave based upon conductivity, temperature, and depth data acquired during the Long-range Ocean Acoustic Propagation Experiment
Authors: Grigorieva Natalie S. , Fridman Gregory M.
Published: October 2013

In the LOAPEX experiment at some distances from VLA the sound source was deployed to depths quite close to the sound-channel axis. This took place at stations T1000, T500, T250, and T50 where, in particular, the source was deployed to 800 m and the depth of the sound-channel axis at these ranges is about 680 m. The interference of the wave fields corresponding to near-axial rays leads to formation of a complex interference wave (‘‘the axial wave’’) that propagates along the axis being a component of the axial crescendo. The talk will present the results on simulation of the axial wave as a function of depth of the receiver and the calculation of its arrival time at frequencies 56.25–93.75 Hz. In the time domain the pulse propagation modeling is carried out for the broadband acoustic signals with the pulse center frequency of 75- and 37.5-Hz bandwidth. The obtained results are compared with those for the lowest mode in the adiabatic approximation. Calculations are made for the range-dependent ocean model based upon LOAPEX CTD data and use the integral representation of the axial wave in a local coordinate system introduced in the vicinity of the range-variable sound-channel axis. [Work supported by ONR.]
Modal group time spreads in weakly range-dependent deep ocean
Authors: Udovydchenkov Ilya A , Brown Michael G
Published: October 2013

Modal group time spreads in deep ocean environments are investigated. The environments considered consist of a range-independent background on which a range-dependent perturbation, due for example to internal waves, is superimposed. Modal group time spreads are defined to be the temporal spread of acoustic energy with a fixed mode number across a nonvanishing frequency band. It is shown that there are three contributions to modal group time spreads that combine approximately in quadrature. These contributions are (1) the recriprocal bandwidth, (2) a deterministic dispersive contribution, and (3) a scattering-induced contribution. Contributions 2 and 3 are shown to be controlled by the waveguide invariant β(m,f), a property of the background sound speed structure. Numerical simulations are shown to be in good agreement with theoretical predictions. [Work supported by ONR.]
Long-range ocean acoustic propagation experiment (LOAPEX) acoustic modeling analysis using measured environmental data
Authors: Wolfson Michael , Henyey Frank
Published: October 2013

One objective of LOAPEX concerns the range dependence of multiple forward scattering for broadband, long-range acoustic transmissions. Using environmental data extracted during the experiment, a sound speed field is constructed, which includes sound speed fluctuations due to neutrally buoyant intrusions as well as internal waves. This sound speed field is used as input to a full wave simulation model. Range-dependent results from simulations regarding the coherent field and depth scattering below lower turning point caustics are presented.
On the forward problem of mode coupling through shallow-water nonlinear internal waves
Authors: Colosi John , Young Aaron
Published: October 2013

Using the Dyson series, we have developed a 2-D (depth and range) theory to predict the coupling of low-frequency acoustic modes propagating through shallow water nonlinear internal wave fields. Parabolic equation numerical simulations with typical shallow water internal wave fields show that the theory can accurately predict mode coupling up to an acoustic frequency of about 300 Hz. Second-order theory may extend the results to higher frequency and larger amplitude internal waves. Application of the theory to 3-D problems in which azimuthal coupling is weak will be discussed.
High-frequency current tomography in coastal regions
Authors: Badiey Mohsen , Karjadi Entin
Published: October 2013

In deep-water tomography refracted ray paths can provide accurate account of travel time for the inverse problem. However, in shallow coastal regions, due to the geometry of the source-receiver as well as the waveguide dimensions, most acoustic energy is a multiple reflection from sea surface and sea bottom. This makes the forward problem which deals with resolving the multipath structure of the arriving signals difficult. In this paper, we discuss the limits of reciprocal acoustic transmission as a function of waveguide temporal and spatial parameters for the purpose of tomography application in coastal regions. Results from a high-frequency (0.5–24 kHz) quasi-reciprocal tomography experiment in a very shallow-water coastal region are presented. Using these data, the accuracy and limit of current tomography for variable sea states are examined for different center frequencies and bandwidths. [Work supported by ONR.]
Measurement of reduced stress in model kidney stones with increased rate of shock wave delivery in lithotripsy
Authors: Ikeda Teiichiro , Bailey Michael R. , MacConaghy Brian , Crum Lawrence A. , Matsumoto Yoichiro
Published: October 2013

Slow clinical shock wave rates more effectively comminute stones. Higher rates create more cavitation bubbles along the focusing axis. Bubble clouds potentially reflect or attenuate the shock wave and also may collapse less energetically. Here, high-speed photo-elastography was used to visualize the dynamic stress distribution inside a transparent model stone. Photo-elastography records constant-stress lines, making quantification possible. PVDF sensors (4 mm diameter) measured force on the proximal face of the stones. The impulsive force of the shock wave and the cloud collapse at various clinical rates (single shocks, 1 Hz, 2 Hz, 3 Hz) in degassed and non-degassed water were calculated from the measurements. Impulse forces from the shock wave and cavitation collapse were comparable in the range 4−7×10−4 Ns. At clinical rates in gas-saturated water, the stress fringes of the tensile component of the shock wave were reduced; the observable maximum stress was decreased; and impulsive force from the shock and the cavitation were decreased over single shocks. The results are evidence of reduced stress in the stone at higher rates due to attenuation by bubbles and less so to softened cavitation collapse. [Work supported by Grant Nos. NIH DK43881 and NSBRI SMS00402.]
Acoustic coupling can be problematic in shock wave lithotripsy
Authors: Pishchalnikov Yuri A. , McAteer James A. , Neucks Joshua S. , VonDerHaar R. Jason , Pishchalnikova Irina V. , Williams James C.
Published: October 2013

Research to improve lithotripsy has yielded considerable progress in determining mechanisms of SW-action, has led to development of innovative SW-delivery systems, and has offered practical strategies to enhance stone breakage and minimize renal injury. Little attention has been paid to how SWs are coupled to the body. In vitro tests were performed to assess the quality of coupling with a clinical Dornier DoLi-50 lithotripter. A test tank with a Mylar window was coupled to the treatment head using lithotripsy gel. Application of gel as performed in patient treatment always trapped air pockets at the interface, and it took considerable manipulation to eliminate them. Stone breakage was less efficient when air pockets were present, with a linear correlation between percent area of air-pocket coverage and reduction in breakage (p<0.001). Breaking contact and recoupling—as can also occur in patient treatment—reduced stone breakage to ∼10% of air-free coupling. Air pockets created when gel was applied to both surfaces, or with coupling and recoupling, reduced the energy density of the pulse to ∼30%–50% of air-free. Thus, even under controlled conditions, acoustic coupling in SWL can be inefficient. Poor acoustic coupling could be a significant source of variability in clinical shock wave lithotripsy.
Experimental study of micro shock wave focusing for precise medical applications
Authors: Hosseini S. H. R. , Ohki Tomohiro , Takayama Kazuyoshi
Published: October 2013

For applying shock waves to sensitive medical procedures like cranioplasty in a close vicinity of the brain or treatment of myocardial dysfunction, generation of micro underwater shock waves plays an important role. Such delicate applications make limits on usage of conventional shock wave (SW) sources. In the present research a half-ellipsoidal cavity with 20.0-mm minor diameter and the ratio of major to minor diameters of 1.41 was designed as a compact extracorporeal SW source. Silver azide AgN3 pellets ranging from 1.0 to 20 μg with their energy ranging from 1.9 to 38 mJ were used to generate shock waves at the first focal point F1 inside the reflector. Irradiation of a Q-switched Nd:YAG laser beam through a 400-μm optical fiber was used to ignite the pellet. The whole sequences of the shock wave generation, propagation, and focusing were visualized by quantitative double pulse holographic interferometry and time-resolved high speed shadowgraph methods. Pressure histories were measured at the shock wave focusing area F2 by using a fiber optic probe hydrophone. It is concluded that the compact ESW source has suitable characteristics for medical applications.
A constant beamwidth transducer for ultrasonic applications
Authors: Benjamin Kim C. , Van Buren A. Lee , Szelag Jeffrey A. , Petrie Sheridan
Published: October 2013

A new class of transducers that produce uniform wide beams (∼20 deg) at ultrasonic frequencies (∼1–2 MHz) is being developed by the US Navy for ultrasonic applications. These transducers will provide a wide insonified field of view for two-dimensional ultrasonic imaging arrays. The design features a larger volume of active material, relative to conventional planar designs, which allows the application of higher drive fields. The prototype described in this article was driven to 200 VRMS and produced a sound pressure of 203 (dB re Pa at 1 m) at a frequency of 2.0 MHz. The details of the ultrasonic constant beamwidth transducer (CBT) design, its fabrication, and measured performance are presented. The ultrasonic CBT described in this paper will soon be incorporated into the Navy’s Underwater Sound Reference Division (USRD)’s Transducer Standards Loan Program.
Methanol sensor using a shear horizontal surface acoustic wave (SH-SAW) device
Authors: Kondoh Jun , Matsui Yoshikazu , Shiokawa Showko
Published: October 2013

Measurements of liquid properties are important for industry, environmental issues, and human life. Because a surface acoustic wave on 36YX-LiTaO3 is a shear horizontal (SH) mode, the liquid-phase SAW sensor is realized using a crystal. In this paper, we present a SH-SAW-based methanol sensor that functions at high temperature. The SH-SAW propagation characteristics were calculated using a numerical calculation method considering temperature coefficients of the substrate and liquid. Calculation results indicate that the SH-SAW sensor can detect methanol solutions at temperature greater than 50°C. Moreover, the calculated results suggest that the sensor sensitivity increases with increasing temperature. The methanol solutions were measured using the SH-SAW sensor. Concentration and temperature of the methanol solution were varied. Linear relationships between sensor responses and concentration were observed at each temperature. As the numerical calculation results suggest, the sensor sensitivity increases with increased temperature. Based on the experimental results, the detection limit of the sensor was estimated as 0.10% by weight at 60°C.
An application of surface acoustic wave for micro fluid systems
Authors: Kuwano Hiroki , Sato Masato , Bae Jooohyng , Nagasawa Sumito
Published: October 2013

This paper describes an application of surface acoustic wave for micro fluid systems. Owing to its high sensitivity, fabrication easiness, and actuation capacity, current SAW devices are widely used as a chemical sensor and linear motor [Takahashi et al. IEEE Trans. Ultrason. Ferroelectri. Frequ. Control 43, 901 (1996)] as well as SAW devices including filters and SAW-Tag in the field of mobile communication. Furthermore, its applications for actuators in liquid such as liquid streaming [Shiokawa et al., Jpn. J. Appl. Phys. 28(28-1), 126–128 (1989)] and atomizer [Kurosawa et al., Sensors Actuators A 50, 69 (1995)] are very attractive for micro fluid systems such as a micro injector, a micro total analysis system, and a lab-on-chip. In this paper, we propose and evaluate a novel fluid actuator device for micro fluid systems using Rayleigh waves. One of the important issues is a micro pump and fluidic friction of the micro channel for TAS. The surface acoustic wave is one solution for the issue. Some of the fluid dynamics will be discussed.
Development of miniature ultrasonic probe with piezoelectric poly-crystalline film deposited by hydrothermal method
Authors: Hasegawa Tomohito , Endo Akito , Kawashima Norimichi , Takeuchi Shinichi , Ishikawa Mutsuo , Kurosawa Minoru
Published: October 2013

Recently, a PZT poly-crystalline film deposited on titanium substrate using the hydrothermal method was studied actively in our laboratory for development of an ultrasonic sensor. These PZT poly-crystalline films can form PZT poly-crystalline films easily on substrates of complex shape using hydrothermal method. We reported a needle-type miniature hydrophone and the ultrasonic transducer with hydrothermally synthesized PZT poly-crystalline films. Results confirmed that the hydrothermally synthesized PZT poly-crystalline films showed wideband frequency characteristics in the megahertz band of sensitivities. A miniature ultrasonic probe with wide frequency band characteristics of sensitivities is thought to be producible using hydrothermally synthesized PZT poly-crystalline films. Miniature ultrasonic probes were fabricated using hydrothermally deposited PZT poly-crystalline film on the end of 0.6-mm-diam titanium wires. Ultrasonic imaging experiments of a target in water were performed using a fabricated ultrasonic probe with hydrothermally synthesized PZT films. Consequently, it was confirmed that this probe has a center frequency of 16 MHz, a bandwidth of 80%, and distance resolution more than 80 μm. We report the structure and performance of fabricated ultrasound probes with hydrothermally synthesized PZT poly-crystalline films, along with results of imaging experiments performed in water.
Visualization of acoustic resonance phenomena using Kundt’s dust figure method
Authors: Sakamoto Shinichi , Asakura Takumi , Ueno Kanako , Sakimoto Yu , Satoh Fumiaki , Tachibana Hideki
Published: October 2013

It is very effective to visualize a sound field for intuitive understanding of various acoustic phenomena, especially for acoustic education. The most famous and classical visualization technique is the Kundt’s dust-tube method contrived by August Adolph Kundt. He devised this experimental technique to determine the sound velocity in the air by observing the mode pattern of a standing wave excited in a glass tube. The technique can be applied to various other acoustic resonance phenomena. In Japan, Sato and Koyasu applied this technique to a two-dimensional room acoustic model experiment in which the effect of the shape of a reverberation room on the normal modes was examined. Referring to these experiments, the authors made experimental equipment to visualize acoustic resonance phenomena for an educational purpose. In our experiment, two types of two-dimensional boxes with hard surface were prepared. In these boxes, normal modes in a closed sound field and the Helmholtz resonance phenomena, which are essential and important for architectural acoustics, can be visualized. These physical experiments are visually impressive on students in architectural courses and therefore the experiment is efficiently used in architectural acoustic courses.
A toy using vibrations
Authors: Nakamura Kentaro , Ueha Sadayuki
Published: October 2013

This study is focused on a toy using vibrations. The toy is composed of a rectangular wooden bar with ten notches and a thin wooden plate at one end of the bar. The plate has a hole at its center and is loosely put at the bar end using a pin. The plate can rotate freely. If notches on the bar are scratched by another bar, the plate begins to rotate due to the vibrations excited on the rectangular bar. The interesting thing is that the rotation direction can be controlled if the way of rubbing is altered. The operation principle of the toy is revealed through experimental observations. The measurements of vibration locus of the pin help us to understand the rotation mechanism. According to these results, the method to control the rotation direction is explained and the analogy to the operation principle of ultrasonic motors is presented.
Technical listening training: Systematic training program designed to improve auditory sensitivity
Authors: Kawahara Kazuhiko , Takada Masayuki , Iwamiya Shin-ichiro , Nakajima Yoshitaka , Ueda Kazuo
Published: October 2013

Technical listening training is a systematic training program designed to improve auditory sensitivity. Through this program, students can obtain the necessary auditory sensitivity before gaining work experience on the job. The type of auditory sensitivity acquired through experience depends of course on the occupation. In contrast, technical listening training provides wide varieties of experiences, so that students can obtain auditory sensitivities associated with various fields and easily adapt to new auditory environments. Technical listening training was developed at the Department of Acoustic Design of the Kyushu Institute of Design. The program has been improved and is still included as part of the curriculum of the Department of Acoustic Design. The present demonstration exhibits the concept of technical listening training as well as its practical application at the School of Design, Kyushu University.
WWW-based multilingualized system for technical listening training
Authors: Nishimura Akira
Published: October 2013

A WWW-based system for technical listening training is proposed. Messages from the system shown in a WWW browser are multilingualized using the GNU gettext mechanism. A system administrator can easily set up the system in a user’s language by translating the message catalog. The WWW-based training system is superior to previous training systems in the following respects: (1) software and hardware can be organized more easily; (2) modification and creation of the contents of training are simple; (3) individual training parameters can be set for users; (4) many users can use the system individually or simultaneously; (5) the results of training for users are saved and summed individually; and (6) difficulty of discrimination training is automatically set up individually. Training experiments of intensity discrimination and frequency discrimination were performed using a prototype of the training system for subjects who were naive to auditory experiments. Significant improvements in the abilities of both intensity and frequency discrimination were observed from results of these experiments. The system is guaranteed to be legal for use, distribution, and modification under the terms of the GNU General Public License. Demonstrations and software packages of the system are distributed at http://adlib.rsch.tuis.ac.jp/∼akira/atsdemo/index—en.html.< ppa>
Beamforming with multiple acoustic sources in the classroom
Authors: Tucholski Edward
Published: October 2013

Superposition of multiple sources, constructive and destructive interference, and beamforming are common topics in undergraduate acoustics. While the mathematical models of these topics are fairly easily performed by students, particularly in the far field, the learning experience is enhanced with simple visualizations and by actually building the model with speakers and measuring the resulting amplitude at various angles with a microphone. While this experiment is often performed in an anechoic chamber for best agreement between theory and experiment, the apparatus will work in a typical classroom as a demonstration. The uncomfortable tonal noise in the classroom is eliminated if ultrasonic (30–50-kHz) sources are used. Apparatuses to be demonstrated have been used successfully at the U.S. Naval Academy in both majors and basic physics classrooms, where the professional development of every officer requires an understanding of sensor beamforming.
Manuscript preparation with LyXforJASA
Authors: Burgess John C.
Published: October 2013

LyXforJASA is a graphical software package for creating manuscripts that meet the submission requirements of the Peer-X-Press (PXP) system used by the Journal of the Acoustical Society of America (JASA). Its main features are graphical templates for superscript and author-year citation styles and for single figures. It is based on LyX, a screen-based graphical user interface (GUI) to the LaTeX typesetting language. Authors see manuscript content, not LaTeX code. LyX liberates authors from document bookkeeping, such as spacing, font selection, and section, equation, figure, table, and citation numbering. LyX has a comprehensive, point and click, GUI mathematics editor with an extensive list of symbols. It can export text in LaTeX, PDF, PostScript, and ASCII formats. It has been ported successfully to Linux, Macintosh OSX, and Windows XP. LyXforJASA packages can be found at http://ww2.hawaii.edu/∼jcb/LyXforJASA/LyXforJASA.html ww2.hawaii.edu/∼jcb/LyXforJASA/LyXforJASA.html
Acoustics of the Korean percussion instruments pyeongyeong and pyeonjong
Authors: Yoo Junehee , Rossing Thomas D.
Published: October 2013

Pyeongyeong is a set of 16 L-shaped chime stones and pyeonjong is a set of 16 oval chime bells. Vibrational mode shapes and mode frequencies of the pyeongyeong determined by holographic interferometry and by experimental modal testing agree very well with those calculated using finite-element methods. A model of the pyeongyeong in which the geometry can be varied shows that the actual shape is probably the one that gave the preferred sound. Vibrational mode shapes and frequencies of the pyeonjong, also determined by holographic interferometry and by experimental modal testing, are split into doublets due to the oval shape of the bells. The splitting is less than in Chinese two-tone bells but it gives rise to audible beats, as in large Korean temple bells.
Acoustics of the Tibetan long trumpet
Authors: Campbell Murray , Myers Arnold
Published: October 2013

The Tibetan long trumpet, or dung-chen, is a metal horn made in several telescoping conical sections. Dung-chen range in length from around 1.3 to over 3 m; the integral mouthpiece is wide and very shallow. Identical pairs of dung-chen are used in rituals of Tibetan Buddhism, often in combination with other instruments. This paper describes bore profile and input impedance measurements on a number of examples of the dung-chen, and compares the acoustical and musical properties of these Asian brass instruments with those of Western European long trumpets and horns.
Comparing the Hawaiian nose flute with the western concert flute
Authors: Ayers Lydia , Horner Andrew
Published: October 2013

This presentation will compare the spectral and expressive characteristics of the Hawaiian nose flute with the western concert flute. The Hawaiian nose flute is a bamboo courtship flute. This presentation will give live demonstrations on several nose flutes and the western flute, along with brief descriptions of the musical and spectral characteristics of these instruments, and then describe the additive synthesis design template used to capture their subtle timbral characteristics using score data in Csound. In addition, the expressive design successfully uses spectral interpolation for the idiomatic ornamental phrasing for each instrument. A special amplitude/frequency function modulation method simulates the trills, which are also slurred within phrases of varying numbers of notes. [This work was supported by the RGC Competitive Earmarked Research Grant 613505, with special thanks to Rodney ‘‘Kala’’ Willis for making the nose flutes.]
Input impedance of asian free-reed mouth organs
Authors: Dieckman Eric A. , Cottingham James P.
Published: October 2013

The khaen, naw, bawu, and sheng are examples of Asian free-reed mouth organs, which incorporate free reeds coupled to pipe resonators. Previous research has shown that the reeds in these instruments behave as blown-open reeds: the playing frequency is above both the natural frequency of the reed and the first peak of the measured impedance curve. Detailed calculations of input impedance have been made for a variety of these instruments, taking into account the position of the reed along the pipe, tuning slots, finger holes, and noncircular cross sections. The details of these calculations are in good agreement with the measured impedances of the same instruments, even in the higher harmonics. A study of the coupling of the free reed and pipe resonator has provided additional details about the influence of the pipe impedance on the playing frequency and sound spectrum of the reed-pipe combination. [Research supported by NSF REU Grant PHY-0354058.]
Model experiments to study sonic boom propagation through turbulence
Authors: Blanc-Benon Philippe , Ollivier Sebastien
Published: October 2013

The aim of this paper is to present data from laboratory-scale experimental simulations of sonic boom propagation through a turbulent atmosphere. The source used to simulate sonic boom N waves is an electric spark source. In order to model turbulence, two setups have been used: a turbulent jet for kinematic turbulence and a heated grid for thermal turbulence. Acoustic measurements have been conducted for three configurations: free field; close to a plane surface in order to simulate ground effects; and close to a curved surface in order to investigate the propagation into a shadow zone. The surfaces were either smooth or rough. With turbulence, many waveforms have been recorded, then the statistics of various parameters, including the peak pressure and the rise time, have been analyzed. In the free field, data show that the increase of the mean rise time and the decrease of the mean peak pressure are linked to the probability of random focusing. The experiments have enabled separate assessment of the effects of turbulence and roughness in the shadow zone caused by the curved surface. Comparison with numerical simulations will be discussed. [This work was supported by European Commission Contract N:G4RD-CT-2000-00398 and French Ministere de la Recherche (Decision 00T0116).]
Toward silent supersonic transport—A fundamental study of supersonic biplane
Authors: Kusunose Kazuhiro , Maruyama Daigo , Matsushima Kisa , Nakahashi Kazuhiro , Yamashita Hiroshi , Yonezawa Masahito , Obayashi Shigeru
Published: October 2013

In this research, aerodynamic design of biplane airfoils in supersonic flight is discussed based on computational fluid dynamics (CFD). In supersonic flight, airfoils generate strong sonic booms and wave drags accompanied by shock waves. New airfoil geometries which significantly reduce shock waves using a biplane concept will be proposed. The background of this concept originates from Busemann biplane and Licher type biplane concepts. In order to focus on the shock-wave characteristics around biplane configuration, inviscid flow (Euler) analyses are performed (which are particularly suitable for wave drag analyses). For the evaluation of the reduction level of shock waves, the wave drag coefficient is used. The design Mach number is 1.7. The aerodynamic design is conducted using an iterative inverse design method that is newly implemented. A biplane configuration with a desired performance has been obtained. Having total maximum thickness ratio of 0.10, it has the lift-to-wave-drag ratio of 21.7 at a desired lift condition for supersonic flight. At the range of lift coefficient more than 0.14 this designed biplane has lower wave drag than that of a (zero-thickness) single flat plate airfoil. This result will lead to the realization of silent supersonic transport.
Motion perception of the target sound event under the discriminated two sound events
Authors: Nishida Tsuruyo , Kakehi Kazuhiko , Kyutoku Takamasa
Published: October 2013

The correct percentage of motion direction for one sound event was about 90%. In the case of two sound events, the correct percentage was lower than for one sound event. The sound event was presented through the headphone in these experiments. These two sound events were physically separated both in frequency and in onset time for the two sound events. It might be possible to perceive two sound events separately. The perception of onset time difference and the discrimination of different frequency sound events were investigated to clarify whether the subjects perceived two sound events distinctly. When IEOI (interevent onset interval) was more than 40 ms, the subjects perceived the onset time difference and the order of two presented sound events. Results clarified that the subjects distinctly perceive two sound events separately with long IEOI. However, the correct percentage for the direction of motion perception of the target in two sound events was significantly lower than for one sound event. The target was strongly affected by the nontarget. Even when two sound events are perceived separately in terms of frequency and temporal order, it is difficult to perceive the motion direction of the target.
Frequency dependency of illusory continuity in binaural hearing with respect to interaural time difference
Authors: Iwaki Mamoru , Kitajima Hiroki
Published: October 2013

Illusory continuity is a psychoacoustical phenomenon: when the absence portion of a tone is padded with sufficiently powerful white noise, an intermittent pure tone is perceived as though it were continuous. Many studies have examined this psychoacoustical illusion in monaural hearing, which supports that illusory continuity is observed when no clear evidence of discontinuity exists and when the power of the white noise is sufficiently large to mask the pure tone. In binaural hearing, the authors reported that illusory continuity was observed and that it was related with interaural time difference (ITD) for a single target pure tone of 500 Hz [M. Iwaki and N. Nakamura, INTERSPEECH/EUROSPEECH-2003 (2003) pp. 2065–2068]. This study investigated illusory continuity in binaural hearing for wider frequency ranges of 250–2000 Hz. Results showed that in the lower frequency range, the threshold level of illusory continuity in binaural hearing depended on ITDs between the tone target and noise masker. The increase of the threshold level was minimal when the target and masker have the same ITD. In the higher frequency range, the illusory continuity was independent of differences of ITDs.
Psychophysical estimates of cochlear tuning using simultaneous and nonsimultaneous masking
Authors: Unoki Masashi , Miyauchi Ryota
Published: October 2013

This study attempts to estimate the tuning of an auditory filter, through both simultaneous and forward masking experiments with a notched-noise masker or a sinusoidal masker, to investigate how the effects of suppression affect estimates of frequency selectivity. In these experiments, masked thresholds of the short probe signal (5-ms ramps, no steady state) centered in the masker or delayed from the masker were measured for normal-hearing subjects as a function of the signal frequency (0.5, 1.0, 2.0, and 4.0 kHz), signal level (10, 20, and 30 dB SL), signal delay, and notch-width conditions in the notched-noise masker, or the masker frequency in the sinusoidal masker. ERBs were calculated from derived auditory filters to compare the cochlear tuning. The estimated tunings became much sharper as the center frequency was increased. Moreover, the difference between the tunings of the filter at lower frequencies with either form of masking tended to be smaller than that at higher frequencies. The tuning may be affected by residual effects of suppression due to lower masker components below the signal frequency. [Work supported by special coordination funds for promoting science and technology of young researchers from the Japanese Ministry of Education.]
Perceptual judgment in synchronization of two complex tones and its relation to the cochlear delays
Authors: Aiba Eriko , Tsuzaki Minoru
Published: October 2013

Onset synchrony of components is widely assumed to be an important cue for perceptual unification as a single tone. However, even if the components begin simultaneously, their temporal relation might not be preserved at the cochlear level. The cochlear delay shifts the arrival of a lower component slightly but systematically behind a higher component. This experiment uses two complex tones as a stimulus to investigate whether the cochlear delay imposes a systematic bias in judging the synchrony of two complex tones. The results are compared with those of our previous experiment using two sinusoidal signals, which indicated that the accuracy of synchrony judgment was worse when the higher component preceded the lower one than in the opposite case. These results will be compared with those of a pioneering study, which indicated that the region of judgment on synchrony of complex tones was greater than 30 ms. [Work supported by the Grant-in-Aid for Scientific Research A, No.16200016, Japan Society for the Promotion of Science.]
Sequential amplitude-modulation interference across auditory channels and across ears
Authors: Wojtczak Magdalena , Gregan Melanie J. , Viemeister Neal F.
Published: October 2013

Forward masking has been demonstrated in the amplitude-modulation (AM) domain [M. Wojtczak and N. F. Viemeister, J. Acoust. Soc. Am. 118, 3198 (2005)] for masker and signal imposed on the same carrier. This study explores an effect of AM on detection of AM imposed sequentially on a different carrier. Data show that a 40−Hz AM (interferer) imposed on a 2−kHz carrier affects detection of a 40−Hz AM (signal) imposed on a 5.5−kHz carrier after the offset of the interferer AM. The effect is analogous (and similar in size for the shortest interferer−signal delays) to modulation detection interference for simultaneous interferer AM. In another condition, two independent noise samples were presented to opposite ears. In one ear, a 40−Hz masker AM was imposed on the carrier. In the opposite ear, a 40−Hz signal was imposed on the carrier after the offset of the masker modulation. A forward−masking effect similar to but smaller in size than that in monaural presentation was observed. The data from both experiments suggest that the forward−masking effect in the modulation domain occurs at central stages of processing, where information is combined across peripheral channels and where binaural interactions occur. [Work supported by NIH Grants DC00683 and DC006804.]
Effect of flanker band number and excitation pattern symmetry on envelope comparisons in masking release
Authors: Yasin Ifat , Fantini Deborah A. , Plack Christopher J.
Published: October 2013

Greater masking release (MR) is observed when narrow-band noise flanker bands (FBs) are lower, rather than higher, than the signal frequency. This may be due to more effective signal coding on the high-frequency side of the excitation pattern (EP) [B. C. J. Moore and U. Jorasz, J. Acoust. Soc. Am. 100, 2373–2379 (1996)]. If so, masking of a high-frequency signal (asymmetric EP) should lead to a greater MR between FBs below and above the signal frequency than for a lower-frequency signal (symmetrical EP). Masked signal thresholds were compared for pure-tone signals (0.5, 1, or 2 kHz) masked by a narrow-band noise masker centered at the signal frequency [on-frequency band (OFB)] and two (three) FBs at 2-ERB intervals, below (above) the signal frequency. Masked signal thresholds were also measured in the absence of FBs. The OFBs and FBs were modulated at a modulation depth, m, of 0.7. FB envelopes were the same as each other and that of the OFB (comodulated, C), the same as each other but independent of OFB (incoherent, I), or not modulated (unmodulated, U). No clear relationship was found between signal EP symmetry and MR magnitude. MR is susceptible to the computation used, i.e., [(I+U)−C] or [I−C] as well as level cues.
Timing perception of sequences with no obvious onset: Isochrony detection in sequences of complex tones connected by formant glides
Authors: Tsuzaki Minoru , Tanaka Satomi , Kato Hiroaki
Published: October 2013

To investigate the perceptual cues that detect arrivals of new auditory events, the detectability of deviation applied to an isochronous temporal structure was measured. The stimuli were sequences of complex tones whose formant frequencies alternate between two steady values. Five steady parts were connected by four formant glides. The isochronous structure was introduced exclusively in the intervals between the starting points of the glides or in the intervals between the ending points by adjusting the durations of the glides and the steady parts in a compensatory manner. Since the harmonic components stop and start one after the other during the glides, it is difficult to define the arrival of new events in an entirely physical view. The perceptual difference in detectability between the starting and ending conditions and its dependency on the frequency region could reveal the perceptual cues that are effective in extracting temporal relations of auditory events. The results will be compared with those obtained with sinusoidal stimuli whose frequencies were modulated in a similar way as the formant frequency in this paper, and they will be discussed by reference to a computational model of auditory event detection. [Work supported by JSPS No. 16200016.]