bluuebunny/crossref_metadata_2025 huggingface dataset:
Improvement of the Fast Breeder Reactor Plant Dynamic Analysis Code ADYTUM
Authors: Tatewaki Isao , Endo Hiroshi , Ishizu Tomoko , Shindo Yoshihisa
Published: October 2013

Japan Nuclear Energy Safety Organization, JNES has been studying the methodology to apply the risk informed regulation (RIR) to the safety regulation for Light Water Reactors (LWRs) and Fast Breeder Reactors (FBRs). A best estimate code of plant dynamic analysis is necessary for the RIR application and it must be validated very carefully.

To fulfill this requirement, JNES has been developing a FBR plant dynamic analysis code ADYTUM, which has flexible code structure and algorisms for applying to the safety evaluation. ADYTUM is composed of several inherent components of physical model named “module”, based on one-dimensional flow network model which calculates the sodium flow and the heat transfer between sodium and structures in primary and secondary loop systems. In addition, ADYTUM is designed so that variables of each module have no connection with other modules. Therefore, ADYTUM allows us to calculate and validate each module alone [1].

In order to reinforce the precision of the analysis model of ADYTUM, we are trying to quantify the uncertainty of the model parameters by use of the Code Scaling, Applicability, and Uncertainty (CSAU) methodology for the primary pump stick accident in FBRs. The approaches of the CSAU are (1) to define the physical value and the range of time scale which are focused on, (2) to select the input parameters which have a profound effect on the physical value of focus by use of the phenomena identification and ranking table, and finally (3) to provide the uncertainty quantification of the focusing value.
A Pre-Test CFD Analysis of HLM Fuel Pin Bundle
Authors: Di Piazza Ivan , Scarpa Marco , Tarantino Mariano
Published: October 2013

A pre-test CFD analysis has been performed for the new Fuel bundle experiment to be carried out in the CIRCE facility. For a fixed pitch to diameter ratio of 1.8, fully developed and 3D analysis are presented for the elementary subchannel. The full 3D subchannel with non-active zones and spacer grids is simulated to study the entry effects and the local perturbation induced by the grid. The thermal peaking factor and the pressure loss induced by the central spacer grid is also evaluated.

In liquid metals, due to the low Prandtl number, the thermal boundary layer is much larger than the mechanical one, and therefore the bulk temperature does not coincide with the central channel temperature. On the basis of computational results, the ‘correct’ heat transfer coefficient based on wall temperature and bulk temperature is compared with the practical experimental measurement evaluation based on wall-thermocouples and central channel temperature. Moreover, The realistic non-uniform heat flux of the pins is taken into account in order to evaluate the local variation of heat transfer coefficient and temperature due to this effect.
Lifetime Assessments of an Old Westinghouse-Design Steam Chest
Authors: Rahman Sazzadur , Abbasi Waheed , Joyce Thomas W.
Published: October 2013

Fossil steam turbines were designed for approximately thirty years of reliable operation based on a normal duty cycle. During operation, highly stressed components of steam turbine power plants undergo a change in material properties due to cyclic stress and exposure to different temperatures. Among all the components of a steam turbine, the steam chest is affected the most as it experiences a wide variation of stresses and loads during transient events and steady-state operation. These factors can strongly influence the metallurgical condition and overall reliable life of steam chests. In this paper, Siemens’ overall approach for lifetime assessments will be discussed with a real life example on a 40 year old Westinghouse-design steam chest. The methodology and the findings from the assessment are also discussed.
Calculation of Curvature Using Linear Thermal Gradient
Authors: Bae Sungjin
Published: October 2013

Reinforced concrete structures for nuclear power plants are designed for thermal effects. When a structure is subject to transient temperature rise, the temperature distribution in a member becomes nonlinear. Commentary of ACI 349 code provides a method of converting a nonlinear temperature distribution to an equivalent linear temperature distribution in order to facilitate calculating curvature due to temperature change. However, the accuracy of estimated thermal curvatures for concrete sections with a liner plate needs to be examined because the ACI 349 method is based on a pure concrete section.

The objective of this paper is to investigate the accuracy of thermal curvatures calculated using the equivalent linear temperature distribution for concrete sections with a liner. Temperature distributions across concrete sections are obtained from heat transfer analyses. Free thermal curvatures are calculated by converting temperature distribution to the equivalent linear temperatures and compared with those from a finite element analysis. Based on the study, the modified expression for linear thermal gradient is proposed which includes the effect of liner on curvatures.
The Analysis of Partial Flow Blockage Accidents for a Sodium Cooled Fast Reactor
Authors: Chang Won-Pyo , Ha Kwi-Seok , Lee Kwi-Lim , Jeong Hae-Yong
Published: October 2013

Analyses were performed for flow blockage accidents postulated in a conceptual design of a 600 MWe demonstration sodium cooled fast reactor with 3 types of core designs, i.e., Uranium, *L-TRU (TRansUrium) and **M-TRU cores, using the MATRA-LMR-FB code. The analysis was addressed for the 6 sub-channel blockage which is a design basis event (DBE). The accidents for 24 and 54 sub-channel blockages were also analyzed to estimate the extent of the blockage size which could lead to sodium boiling or fuel melting. Three radial blockage positions were also taken into account in the analysis.

In result, a higher maximum coolant temperature in the subassembly was obtained as the number of blocked subchannels increased. A recirculation region was usually developed right above the blockage for large blockage cases. The analysis results showed that a favorable safety margin was assured for the design basis event, i.e., the 6 sub-channel blockage accident. For the 24 and 54 sub-channel blockage cases, the peak cladding temperature limit was breached, and there was a case in which fuel melting could be threatened.

* TRU extracted from LWR fuel

** Mixture of L-TRU and TRU extracted from self-recycled SFR fuel
Distributed Energy Storage Control for Optimal Adoption of Solar Energy in Residential Networks
Authors: Arghandeh Reza , Broadwater Robert
Published: October 2013

Environmental concerns, global warming and fossil fuel prices are creating a shift in the expectations of consumers and industries to move toward renewable energy resources. However, the inability to control the output of renewable resources, like wind and solar, results in operational challenges in power systems. The operational challenges of renewable resources can be met by energy storage systems. The energy storage systems scheduling can be used to control the effect of intermittent renewable energy resources. Furthermore, energy storage systems can be used for ancillary services, peak reduction, and mitigating contingencies in the distribution and transmission networks [1].

Distributed photovoltaic (DPV) rooftop panels are considered as renewable energy resources in this paper. Depending on the DPV size and solar irradiation, DPV adoption can create problems for the distribution network. In addition, utility companies have to pay different prices for electricity during different times of the day due to the dynamic electricity market. Therefore, the DPV adoption can be controlled with the help of real-time electricity price and the load profile.

Facing these challenges, this paper presents an operational optimization algorithm for a Distributed Energy Storage (DES) system. The DES system presents a fleet of batteries connected to distribution transformers. The DES can be used for withholding DPV power before it is bid into the market. Withholding DPV generation represents a gaming method to realize higher revenues due to the time varying cost of electricity. Energy storage systems may be used to control DPV power variation and thus help distribution network operations [2].

The objective of this paper is to present a DES optimal economic control system to improve the DPV adoption in power distribution networks. The control system decisions depend on the load profiles, and the real-time Locational Marginal Price (LMP).

Economic operation of the DES is a complex problem because of the time dependency of the battery capacity (where sufficient energy reserves must be maintained in case of power loss), the solar irradiation uncertainty, and the real-time electricity price variability. The mathematical approach used is the Discrete Ascent Optimal Programming (DAOP) algorithm. An advantage of DAOP is its assurance of convergence after a finite number of computational iterations.
Vibration Isolation System to Reduce High Frequency Vibrations due to Airplane Crash
Authors: Niwa Hiroshi , Watanabe Urara , Warashina Masahiko , Tanoue Tetsuharu
Published: October 2013

Electrical panels in Nuclear power plants are usually designed to be rigid enough to reduce seismic response. However, design dynamic loadings for nuclear power plant are not only seismic loadings. The airplane crash (APC) load is also important dynamic load for nuclear power plant equipments. If the electrical panels are rigid enough for seismic loadings, the higher-mode vibrations of local floors due to the airplane crash will excite resonant vibration of electrical devices inside electrical panels, and so, the panels could lose its electrical functions.

In this study, a vibration isolation system is applied to the electrical panels in order to reduce high frequency vibrations. The system consists of vertical and horizontal isolation rubbers which support four corners of lower end of electrical panels. Using this system, acceleration responses of panels during high frequency excitation due to airplane crash and so on, are reduced less than floor response. However, the rocking mode vibration is excited during an earthquake, because of its predominant frequency. Therefore, in the vibration isolation design, it is important to consider coupled vibration of horizontal and vertical mode and set the natural frequencies in the range that avoids spectrum peaks of acceleration, peaks arising from both the impact vibration and the seismic wave. In this paper, the design method and the vibration test are presented.
An Advanced Model on Mixed Convection in Passive Containment Cooling System
Authors: Zhang He , Niu Fenglei
Published: October 2013

In order to improve the accuracy of the heat transfer capability evaluation for passive containment cooling system (PCCS) in China’s advanced pressurized reactor (CAP1400), an advanced simulation model is developed based on stratified phenomenon in large enclosures, in which one–dimensional differential equations are used to get temperature and velocity profiles for the ambient fluid. The mixing and heat transfer experiment in a large rectangular enclosure with an injected buoyant jets and a cooled vertical surface is analyzed as an example, which simulates a break flow for passive reactor containment system. The results of the new model have good agreement with that of ANSYS CFX Version 12.1, while the running time of the new model is only about 20% of the time ANSYS CFX takes.
The importance of the direct to reverberant ratio in the perception of distance, localization, clarity, and envelopment, Part two.
Authors: Griesinger David
Published: October 2013

Part two explores the practical consequences of the observations in part one. An experimental method will be presented for objective tests on direct sound detection that yield the threshold data in part one. The rate at which the forward integrated reverberation increases to the level of the direct sound from a short note, and the D/R from short notes or syllables is found to be of particular importance. The insensitivity of current acoustic measures to the perception of direct sound will be discussed, and new measures will be proposed that can be used with live music and speech. We will also present subjective and objective results from a series of experiments in a small hall at the Longy School of Music in Cambridge, Massachusetts. Selective addition of absorption to the stage area and to the lateral walls greatly improved subjective clarity and the balance between musicians on stage and in the hall. Electroacoustics was applied to restore the late reverberation to the value of the unmodified hall without altering the improved clarity. The changes were enthusiastically received by the participants. Audio examples from these experiments will be demonstrated.
Comparisons of different microphones, microphone orientation, and spacing on late lateral energy measurements.
Authors: Giacomoni Clothilde , Scherma Amy , Vigeant Michelle C.
Published: October 2013

A strong correlation exists between listener envelopment and late lateral energy [J. S. Bradley and G. A. Soulodre, “Objective measures of listener envelopment,” J. Acoust. Soc. Am. 98, 2590–2597 (1995)], but limited work has been conducted on measuring this parameter in actual spaces. Measuring late lateral energy (GLL) requires a figure-of-eight pattern microphone to measure the lateral energy only, but an omnidirectional microphone is also used simultaneously to measure other common room acoustic parameters. An investigation was conducted to determine the effects of various different microphones, microphone orientation, and the spacing between the bidirectional and omnidirectional microphone on measured GLL values. Eight figure-of-eight pattern microphones were used, including both ribbon [(1) Cascade Fat Head II, (2) Royer R-121] and condenser [(2) AKG C414, (1) Neumann KM120, (2) Shure KSM44] microphones. Measurements were taken in an 80-seat lecture-style classroom, using the sine sweep method. The microphones were positioned at three different spacings from the omnidirectional microphone, in both orientations at one spacing, and two different receiver locations. In general, differences of 1–2 dB were found between all of the microphones, while minimal differences were found between the two orientations and various spacings for each microphone. Implications of the results for GLL measurements are discussed. [Work supported by University of Hartford WELFund.]
Perceptual alignment of early-to-late-reverberant energy ratio and reverberation time to match visual environmental cues of a music performance.
Authors: Valente Daniel , Braasch Jonas
Published: October 2013

The subject of auditory-visual integration has become increasingly important with the introduction of high-resolution playback devices for on-screen object segregation. What effect does the visual location of an object have on a participant’s expectations of that object’s auditory stimulus? Several studies have looked at the phenomenon in recent years, but these studies rely on static photographic images to represent the visual scene and mostly use speech signals for testing. Building on these studies, our aim is to propose a testing method using monochromatic compositing (blue-screen technique) to locate a music performance recorded in a studio in a number of virtual acoustical environments being assessed by a listener. In this study, the participant is asked to perceptually adjust two acoustical parameters, early-to-late reverberant energy ratio and reverberation time, of two music performances in five contrasting visual environments according to his or her expectations of how the room should sound given its visual appearance. This study reveals participant resiliency in the presence of forced auditory-visual mismatch; participants are able to adjust the presented acoustic modeling algorithm in a statistically similar way despite randomized starting values for the monitored parameters. Subjective results of the experiment are presented along with objective measurements for verification.
Influence of vibration on the perception of musical instruments for various stage constructions.
Authors: Abercrombie Clemeth L. , Braasch Jonas
Published: October 2013

Expanding use of multisensory music presentation calls for increased knowledge of human response to audio-tactile stimulus. This presentation outlines an experiment to explore the human ability to distinguish differences in tactile signals generated by musical sources on typical floor constructions. A double bass and bass drum are used to generate binaural audio and tactile signals on various floor constructions. Vibration signals are then compared for differences in arrival time, magnitude, and frequency content. Audio and vibration signals are reproduced in different combination using a calibrated motion platform and headphones. Test participants are asked if they can identify the differences in tactile signals given a fixed audio environment. Test results are compared to those found in other studies obtained using musical signals as well as harmonic and noise signals. The importance of calibrating tactile musical signals is discussed along with the implications of the results with respect to tactile signal synthesis for multimodal music presentation.
Evolution and diversity of batrachoidid vocalizations.
Authors: Rice Aaron N. , Bass Andrew H.
Published: October 2013

Despite the fact that toadfishes are one of the best-studied taxa for understanding fish vocal communication, vocalizations have only been recorded from a low proportion of taxa within the family. Here, we describe the diverse vocal repertoire and novel swimbladder morphology of a tropical Pacific euryhaline toadfish, Batrachomoeus trispinosus. B. trispinosus produces four classes of vocalizations: long duration hoots, grunts, grunt trains, and grunts exhibiting acoustic beats; the majority exhibiting prominent harmonic features. Calls with acoustic beats, previously unreported for any individual actinopterygian taxon and convergent with songbirds, typically had a predominant frequency around 2 kHz with a beat frequency around 300 Hz. B. trispinosus possesses a bilaterally divided swimbladder, forming two completely separate bladders. Grunts exhibiting beats may be produced by bilateral control of the bladders. Phylogenetic analysis based on available molecular data show that B. trispinosus and Halobatrachus didactylus represent basal lineages in the Batrachoididae, and the separated swimbladders are an independently derived feature of B. trispinosus. Thus, the toadfishes may possess higher levels of vocal, motor, and morphological diversity than previously appreciated, and now provide a framework for understanding integrated mechanisms underlying the evolution of acoustic novelty in fishes.
Bocaccio sounds in the Southern California Bight.
Authors: Širović Ana , Demer David A.
Published: October 2013

Sound production by many fish species has been studied extensively, but little is known about sound production by rockfishes (genus Sebastes), and only a few species have been reported to be soniferous. Passive acoustic recordings were made during 2007 and 2008 at Hubbs-SeaWorld Research Institute and Southwest Fisheries Science Center tanks containing Bocaccio (S. paucispinis). Sounds in tanks were recorded using preamplified hydrophones (HTI-94-SSQ) and were digitized at sample rates of 44,100 or 8000 Hz. Recordings were collected at 14 locations in the Southern California Bight (SCB) using passive acoustic moorings, AURALs, sampling at 8000 Hz from August through October 2007. Three low frequency (<900 Hz), short duration (<4 s) sounds were recorded in tanks containing only Bocaccio multiple times. One of these sounds was also commonly recorded in the SCB and is the same sound that was recorded first by Thompson off San Clemente Island in the 1960s. This sound exhibited the same diel pattern as noted by Thompson, with maximum calling at night, peaking at dusk and dawn. This long-term persistence of the same sound indicates that passive acoustic tools may be used for efficient monitoring of changes in rockfish populations over long time periods.
Coherence in long-range deep ocean propagation.
Authors: Brown Michael G. , Beron-Vera Francisco J. , Udovydchenkov Ilya A. , Rypina Irina I.
Published: October 2013

Acoustic wavefield structure, stability, and coherence properties in deep ocean environments will be discussed. Properties of transient wavefields will be emphasized. Observations, simulations, and some theoretical considerations will be presented. Some important experimental milestones, beginning approximately in 1979, will be noted. It will be argued that the last 30 years have been characterized by a number of pleasant surprises relating to the stability and coherence of transient wavefields in deep ocean environments. [Work supported by ONR.]
Acoustical analysis of an indoor test facility for a 30-mm Gatling gun.
Authors: Shaw Matthew D. , Gee Kent L.
Published: October 2013

The Air Force commissioned a construction and engineering company to build an indoor test facility for the GAU-8 Avenger at Hill Air Force Base in Layton, UT. The blast pressures from this 30-mm Gatling gun, however, are large enough to cause spalling of the concrete walls over time. The facility is being designed and constructed to last for 20 yrs, requiring several acoustical treatments. The pressures from the gun were measured outdoors, with maximum pressures exceeding 3000 Pa (163 dB) at a distance of 30 ft (9.1 m). A computer model of the room was designed using EASE, and impulse responses were generated at several positions. These impulse responses were convolved with an ideal blast wave pulse train to mimic the sound of the gun in the room. From these data and results collected from preliminary tests in the range, recommendations have been provided as to placement and types of necessary treatments. [Work supported by HHI Corporation.]
The prediction of airflow generated noise in ventilation system bends.
Authors: Waddington David C. , Oldham David J.
Published: October 2013

This paper describes recent work on the prediction of airflow generated noise in ducts based upon pressure loss characteristics. Strategies employed to reduce turbulence by smoothing the flow around a bend include the use of turning vanes, and a large radius of curvature with the associated use of splitters. The effect of these strategies on the regenerated noise is examined for a range of common bends including mitred bends, with and without turning vanes, and radiussed bends, with and without splitters. The effect of bends with different aspect ratios is also examined. An excellent collapse of measured data onto a single characteristic curve is reported for each configuration based upon standard values of pressure loss coefficients. It is suggested that that these characteristic curves might form the basis for a practical prediction method.
A talking robot and the interactive speech training for hearing-impaired.
Authors: Sawada Hideyuki
Published: October 2013

A speech trainer employing a talking robot for auditory-impaired people will be introduced. The talking robot consists of mechanically-designed vocal organs such as a vocal tract, a nasal cavity, artificial vocal cords, and a sound analyzer with a microphone system, and the mechanical parts are fully controlled by ten servomotors for generating humanlike voices. The robot autonomously learns the relation between motor control parameters and the generated vocal sounds by an auditory feedback control, in which a Self-organizing neural network is employed for the adaptive learning. By employing the robot and its properties, the authors have constructed an interactive speech training system. The training is divided into two approaches; one is to use the robot for showing the shape and the motion of the vocal organs, and the other is to use a topological map for presenting the difference of phonetic features of a traine’s voices. While referring to the robot motions and the phonetic characteristics, a trainee is able to interactively practice vocalization for acquiring clear speech with appropriate speech articulations. To assess the validity of the training system, a practical experiment was conducted by 19 subjects in a school for the deaf children. The talking robot is expected to intensively teach auditory-impaired patients the clear speech articulations.
Optimization of articulator trajectories in producing learned nonsense words.
Authors: Tiede Mark , Mooshammer Christine , Goldstein Louis , Shattuck-Hufnagel Stefanie , Perkell Joseph , Matthies Melanie
Published: October 2013

Previous work assessing motor learning in novel speech utterances has shown that kinematic duration and variability are reduced as a function of practice [Schulz et al. (2001)]. In this study EMA was used to observe articulator movements during production of a variety of polysyllabic nonsense words conforming to English phonotactics (e.g., “thraimpoframodis”). Target words were elicited eight times in block-random order, with each block separated by ten minutes of an unrelated task serving as a distractor. Analysis of EMA sensor trajectories between initial and final repetitions shows in general reduction of overall duration, lower STI [Smith et al. (1995)], reduced stiffness, and fewer acceleration peaks, with intermediate productions indicating that these trends occur asymptotically. Comparison of consonant closure timings delimited using velocity extrema and aligned through nonlinear time normalization [Lucero et al. (1997)] suggests that as fluency increases, the overlap between adjacent consonantal gestures also increases. The patterns of articulatory optimization illustrated by these results will be contrasted with similar analyses of real but difficult-to-pronounce sequences (tongue twisters) collected from the same subjects, with the goal of identifying similarities between pre-fluent and dysfluent utterances. [Research supported by NIH.]
Measuring articulatory similarity with algorithmically reweighted principal component analysis.
Authors: Mielke Jeff , Roy Joseph
Published: October 2013

Articulatory similarity was assessed for a corpus of 2700 ultrasound images of 75 cross-linguistically frequent speech sounds produced by four subjects in three segmental contexts (a_a, i_i, u_u). Cross-distances were generated for the entire length of the vocal tract using the Palatron algorithm and realistic estimates of the location of the pharyngeal wall and teeth, resulting, after interpolation, in 60 cross-distances per token. A standard principal component analysis of these data is overwhelmed by the coarticulatory effects of the context vowels. Algorithmically reweighted principal component analysis was devised in order to use coarticulatory variation to isolate the most distinctive cross-distances for each target segment. The reweighting algorithm considers the variance across repetitions in each of the 60 cross-distances, as well as variance in the slope of the cross-distance function, in order to identify areas of stability across tokens. For each target sound, cross-distances with the greatest variance are reset to the mean for all target segments, while cross-distances with the least variance maintain their original values. This has the effect of defining each target sound by the cross-distances, which are most stable across contexts.
Gestural intrusions in Taiwanese and English.
Authors: Gao Man , Chang Yueh-chin , Hsieh Feng-fan , Nam Hosung , Tiede Mark , Goldstein Louis
Published: October 2013

Kinematic studies of repetitive speech production tasks involving English sequences such as “cop top” have provided abundant evidence for gestural intrusion errors: errorful constrictions that are co-produced with intended target constrictions (Pouplier and Goldstein, 2005; Goldstein et al., 2007). These intrusions have been analyzed as transitions to more dynamically stable coordination modes. This work investigates Taiwanese speakers’ production of similar repetitive sequences such as [kap tap]. If the speech sequences are planned and executed in Taiwanese in the same way as in English, similar patterns of intrusive speech errors should be observed. However, analysis of the kinematic data from three speakers shows that these effects in Taiwanese differ from those in English in a number of ways. A systematic comparison of Taiwanese and English intrusions is presented in terms of frequency of occurrence (much higher in Taiwanese), standard deviation of magnitude (smaller in Taiwanese), and temporal relationships to intended gestures. The results are discussed with respect to the language-specific regularities of gestural coordination and their implications for the mode-locking account of speech errors. [Work supported by NIH-NIDCD DC008780.]
Computationally efficient parabolic equation solutions to seismoacoustic problems.
Authors: Collis Jon M.
Published: October 2013

Improving the capabilities and accuracy of the elastic parabolic equation method has been an active area of research. Variable rotation [D. A. Outing et al., J. Acoust. Soc. Am. 120, 3534–3538 (2006)] is an effective solution for treating variable bathymetry and has recently been extended to handle variable sediment thicknesses [J. M. Collis et al., J. Acoust. Soc. Am. 123, 51–55 (2008)] and beach interactions. To accurately resolve the field in elastic sediments, much finer grid spacing may be needed than is necessary to propagate the acoustic field in the water. In particular, as the shear wave speed in the elastic medium approaches zero, the governing system becomes singular, and very fine grid spacing is necessary to capture subtle effects of the field. In this presentation we show how elastic parabolic equation solutions can be computed with greater efficiency, through the use of multiple resolution grids. Interface conditions and derivative approximations on a nonuniform grid will be described. Finally, applications of multiple grid solutions will be discussed for rough surface scattering and treating near-singular low-shear speed sediments.
The swimming motions of fish as hydroacoustic signals.
Authors: Coombs Sheryl
Published: October 2013

Discussions about bioacoustic communication in fishes largely neglect the hydroacoustic fields produced by the swimming motions of fish, focusing instead on sounds produced by stridulation (the rubbing of body parts) and the drumming of swimbladder walls by surrounding muscles. This talk will describe some of the temporal and spatial characteristics of swimming-generated signals, the evidence for their ability to stimulate both the lateral line and auditory systems of fish, and their potential role in behaviorally-relevant contexts, including courtship and spawning, predator avoidance by fish schools, and spatial exploration of novel environments.
Evidence of binaural directional computations in the auditory pathway of a teleost fish.
Authors: Edds-Walton Peggy , Fay Richard
Published: October 2013

Although binaural processing is known to be critical for sound source localization in terrestrial vertebrates, binaural processing for sound source localization in fishes has not been demonstrated. Previous physiological and neuroanatomical studies have indicated that interaural convergence is present in auditory pathway of oyster toadfish (Opsanus tau). In this study, we introduce a reversible method, otolith tipping, to evaluate the presence of binaural inputs. The normal directional response pattern (DRP) was recorded extracellularly for auditory cells in the first-order descending octaval nucleus (DON) or the midbrain torus semicircularis (TS) using directional stimuli in the horizontal and midsagittal planes. The DRP was re-evaluated while gently tipping the ipsilateral or contralateral otolith of the saccule to alter the normal relationship with the auditory epithelium. The DRP was also evaluated post-tipping to ensure no damage had occurred. In the DON, ipsilateral or contralateral tipping most often altered or eliminated spike activity; in the TS, tipping most often caused a change in the shape or orientation of the DRP. The data indicate complex interactions of excitatory and inhibitory inputs, which appear to be associated with the convergence of binaural inputs in the DON and TS. [Work supported by the NIH.]
Auditory saccular potentials of the little skate, Raja erinacea.
Authors: Sisneros Joseph A. , Fay Richard R.
Published: October 2013

Previous behavioral studies have shown that elasmobranch fishes can be attracted to low-frequency sound sources (< 80 Hz) in their natural habitat, but relatively few studies have characterized the auditory response properties of the elasmobranch inner ear to low-frequency sounds. Here, we examine the response properties of evoked saccular potentials from the skate inner ear to determine the auditory threshold sensitivity and frequency response of saccular hair cells to low-frequency stimuli. Saccular potentials were recorded from the medial region of the saccule while sound was generated using a shaker table designed to mimic the particle motion component of sound. Four test frequencies (50, 64, 84, and 100 Hz) and 11 directions were used to characterize the displacement sensitivity, frequency response, and directional response properties of the skate saccule. Saccular potentials were evoked and measured at twice the stimulus frequency in vivo using a wave analyzer, while stimuli were generated via the shaker table system. The right and left saccule appeared to have an omnidirectional response based on our initial measurements, but the frequency response of the skate saccule had lower displacement thresholds at 84 and 100 Hz compared to stimuli at 50 and 64 Hz.
Phylogenetic analysis of high-frequency hearing in teleost fishes.
Authors: Higgs Dennis M.
Published: October 2013

The evolutionary drivers responsible for the selection of high-frequency hearing in teleosts remain unclear. It is generally accepted that low-frequency hearing is the basal (plesiomorphic) condition, with specializations evolving to allow expansion of hearing bandwidth. While selective forces, usually habitat-based, have been proposed to explain the evolution of high-frequency hearing, phylogenetic analysis is currently lacking. The current study examines all available teleost hearing abilities in relation to habitat parameters, salinity, and maximum depth of occurrence of each species. There was no statistical correlation between any of these parameters and maximum frequency of detection and only a weak relationship to best frequency. Phylogenetic position, at the subdivision/superorder level, did significantly predict both maximum and best frequency of detection, but there was no consistent pattern of high-frequency hearing within the Teleostei, suggesting independent evolution of this ability. These trends were also consistent at the family level. The current reanalysis of available data therefore suggests little evidence for the habitat-based hypotheses of high-frequency hearing evolution in the Teleostei. Interesting families and approaches will be highlighted in the current talk in an attempt to foster a more systematic approach to future studies of hearing in fish. [Work supported by NSERC.]
Central auditory processing and neuropeptide modulation of hearing in the damselfish.
Authors: Maruska Karen P. , Tricas Timothy C.
Published: October 2013

Acoustic communication is important for social behaviors in many fishes, but how the central auditory system encodes complex sounds and how neuromodulators influence hearing is poorly understood. The Hawaiian sergeant damselfish produces pulsed low-frequency low-intensity sounds during agonistic and reproductive behaviors, and provides an ideal model to study auditory processing and hormone effects in a species that does not possess special adaptations to enhance hearing. Single-cell recordings were used to (1) compare response properties and sensitivity of auditory neurons between the hindbrain and midbrain to both simple tones and playbacks of complex conspecific sounds, and (2) test the effects of the neuromodulator gonadotropin-releasing hormone (GnRH) on midbrain auditory response properties. Auditory neurons in both the hindbrain and midbrain showed similar high phase-locking ability and best frequencies of 80–400 Hz, but midbrain neurons were more sensitive to conspecific sounds compared to hindbrain neurons. GnRH application to the midbrain showed primarily inhibitory effects on evoked auditory responses, evidenced by a GnRH-induced decrease in spike rate compared to saline controls. These data highlight the importance of using natural stimuli to test hearing abilities, and indicate that GnRH has the potential to influence central auditory processing during natural social behaviors in the damselfish.
Jamming of bat sonar by meadow katydids (Conocephalus).
Authors: Simmons James A
Published: October 2013

Meadow katydids (Orthoptera: family Tettigoniidae, genus Conocephalus) are small (1–2 cm) grasshopperlike insects that congregate in late summer on low bushes and tall grass near ponds where males then emit calls to attract females. These sounds are entirely ultrasonic, consisting of sequences of brief (20–25 ms) bursts, repeated at 30 ms intervals, of 10–20 clicks separated by 1–1.5 ms within each burst. Each click covers frequencies of 20–90 kHz. The same frequencies are used for sonar by big brown bats (Eptesicus fuscus), which frequent the same ponds while hunting for prey and nearly always fly in audible range of the meadow katydids but do not attempt to capture any of them. Calls of several male insects usually overlap at slightly different inter-click intervals so that the acoustic waveform wavers, thus creating moving virtual acoustic sources for the bat’s binaural listening. Aggregate calling is virtually continuous at sound pressures exceeding 90–100 dB SPL at distances of 1–2 m. Neuronal recovery-times in the bat’s auditory system are ∼0.5 ms to accommodate reception of closely-spaced echolocation emissions and multiple echoes, so click bursts will reliably evoke volleys of responses at successive stages of the bat’s auditory pathway, preempting biosonar echoes received by approaching bats.
Relationships between wingbeat and pulse-emission timings in three echolocating bats, Rhinolophus ferrumequinum, Pipistrellus abramus, and Miniopterus fuliginosus.
Authors: Watanabe Yu , Hiryu Shizuko , Riquimaroux Hiroshi , Watanabe Yoshiaki
Published: October 2013

To investigate relationships between flight and echolocation behaviors in one CF-FM (Rhinolophus ferrumequinum) and two FM (Pipistrellus abramus and Miniopterus fuliginosus) Japanese echolocating bats, relationships between wingbeat and pulse-emission timings during landing flight were examined. Wingbeat timings were measured by a dual high speed video camera system (500 fps) and pulse-emission timings were precisely recorded by a wireless telemetry microphone mounted on the bats’ head. The R. ferrumequinum and P. abramus emitted multiple pulses in a burst (pulse trains) per single wingbeat cycle, and pulse-emission timings were perfectly synchronized with their wingbeat, indicating that pulse-emission timings were affected by wingbeat. On the other hand, relationships between wingbeat and pulse-emission timings in M. fuliginosus were different compared with two other bats. The M. fuliginosus never emitted pulse trains, but proportionally increased emission rate of single pulse after approach phase started. As a consequent, pulse-emission timings were controlled regardless of wingbeat, and synchronization between wingbeat and pulse-emission timings was occasionally disturbed during approach phase. These results suggest that we need further discussion about the reason why synchronization between flight and echolocation behaviors appears to be formed by species-specific way among these bats. [Work supported by MEXT of Japan.]
Fractal ladder models and power-law wave equations.
Authors: Kelly James F. , McGough Robert J
Published: October 2013

Extensive measurement of the ultrasonic attenuation coefficient in human and mammalian tissue has revealed a power-law dependence on frequency. To describe this power-law behavior in tissue, a hierarchical fractal network model is proposed. The viscoelastic and self-similar properties of tissue are captured by a constitutive equation based on a lumped-parameter infinite-ladder topology involving alternating springs and dashpots. In the low-frequency limit, this ladder network yields a stress-strain constitutive equation with a time-fractional derivative. By combining this constitutive equation with linearized conservation principles and an adiabatic equation of state, the fractional partial differential equations previously proposed by [M. Caputo “Linear models of dissipation whose Q is almost frequency independent--II,” Geophys. J. R. Astron. Soc. 13, 529–539 (1967)] and [MG. Wismer “Finite element analysis of broadband acoustic pulses through inhomogeneous media with power-law attenuation,” J. Acoust. Soc. Am. 120, 3493–3502 (2006)] are derived. The resulting attenuation coefficient is a power-law with exponents ranging between 1 and 2, while the phase velocity is in agreement with the Kramers–Kronig relations. The power-law exponent is interpreted in terms of the mechanical structure and related to the spectral dimension of the underlying fractal geometry.
Realtime virtual banjo model and measurements using a microphone array.
Authors: Pfeifle Florian
Published: October 2013

A model of a full-scale banjo was programmed in MATLAB and C using the finite differences method. Because of the highly complex algorithm, the model could not be put into practice in real time. A similar model was then written in VHDL, a hardware description language and implemented on a FPGA board. This hardware allows highly parallelized computation at highest clock rates, thereby, a realistic banjo model could be computed in real time. This virtual banjo could now be used to alter instrument-specific parameters in real-time. A large set of tests was conducted ranging from simple calibration of the most realistic parameters to the research of nonlinear effects on the membrane of the banjo. The findings where compared to the measurements of a real banjo done with a microphone array consisting of 128 microphones.
Dampening vibration modes of the snare drum batter head.
Authors: Larkin Barry , Morrison Andy
Published: October 2013

Percussionists have always had to contend with an undesirable ringing sound while performing on the snare drum. It is usually referred to as the “edge ring.” A common method to eliminate this sound comes from placing some type of dampening material on the edge of the drum head. Manufacturers of drums have provided many ways of dealing with this problem including internal dampening devices, customized drums heads, or material designed to be placed on the drum head. Using electronic television holography, it was revealed the source of this “ring” to be the third mode of vibration that produces a pitch approximately one octave and a half step above the fundamental. During this presentation, laser holographic images from the fundamental to the 16th mode will be displayed. In addition, new and recent holography work will show the effect of dampening devices on the third and other modes. “I certify that I have complied with ASA ethical principles” Telephone number: 515.294.2818, FAX: 515.294.6409. Send Notice to Barry Larkin.
Multichannel analysis of surface waves method for shallow soil profile exploration.
Authors: Lu Zhiqu , Sabatier James
Published: October 2013

In order to explore shallow soil properties in a noninvasive manner, a multichannel analysis of surface waves method was employed to obtain soil shear wave velocity profile up to a couple of meters. In the study, an electromechanical shaker operating in a frequency-sweeping mode was placed on the ground to excite Rayleigh waves propagating along the surface. A laser Doppler vibrometer (LDV) was used as a noncontact receiver to detect the surface vibration. The LDV was mounted on an aluminum frame and driven by a stepper motor to move along a straight line. Multichannel surface vibrations were obtained and analyzed to determine the dispersive curve; i.e., the Rayleigh wave velocity as a function of frequency. An inversion algorithm was used to transform the dispersion curve into the shear wave velocity profile. This technique can be developed for the applications of levee and dam evaluation as well as shallow soil properties imaging and characterization.
Does random temporal jitter reduce onset dominance in temporal weighting functions for high-rate click trains?
Authors: Brown Andrew D. , Stecker G. Christopher
Published: October 2013

Several studies have noted poor sensitivity to interaural time differences (ITD) among users of bilateral cochlear implants (CIs) compared to normal hearing listeners. One hypothesis for this impairment is that CI users are subject to a higher degree of binaural adaptation—a loss of sensitivity to binaural cues after onset—than normal hearing listeners, as a result of CI electrical stimulation. [Laback and Majdak, PNAS 15, 814–817 (2008)] demonstrated improved ITD discrimination in CI users by imposing random temporal jitter on CI pulse trains bilaterally. A candidate explanation for this improvement is that temporal jitter causes a “restarting” of the adapted binaural system, and, thus, improved sensitivity to ITD after onset. In the present study, temporal weighting functions of normal-hearing listeners were measured for discrimination of ITD and interaural level differences carried by trains of 4000 Hz Gabor clicks. Interclick intervals of 1.25 and 2.5 s were tested with and without additional random temporal jitter. The results have implications for mechanisms of binaural adaptation as well as for binaural performance in CI users.
Exploring the acoustic basis of consonance using individual differences.
Authors: McDermott Josh H. , Lehr Andriana J. , Oxenham Andrew J.
Published: October 2013

Despite its central role in music, the origins of the preference for consonant over dissonant intervals remains controversial. We applied an individual differences approach to this question. Subjects were first tested for their aversion to pure-tone beats, and to inharmonic spectra of single complex tones. Consistent individual differences were observed in the magnitude of subjects’ aversion to beats and inharmonicity, but the two effects were uncorrelated across subjects, suggesting independent factors. Subjects then rated the pleasantness of musical intervals and three-note chords. If particular acoustic factors determine consonance, stronger sensitivity to those factors should predict stronger musical preferences. In each of two cohorts, only the preference for harmonic spectra was consistently correlated with preferences for consonant over dissonant chords and intervals. Although the strength of a subject’s consonance preference was also correlated with their musical experience, so was their harmonicity preference, which explained most of the effect of experience on consonance ratings. The results suggest that much of consonance perception is rooted in the basic acoustic property of harmonicity. Harmonicity is evidently predictive of important structures in Western music, and with exposure to music, listeners learn to attend to it. [Work supported by NIH grant R01DC05216.]