bluuebunny/crossref_metadata_2025 huggingface dataset:
Acquisition of English word stress patterns in early and late bilinguals
Authors: Guion Susan G.
Published: September 2013

Given early acquisition of prosodic knowledge as demonstrated by infants’ sensitivity to native language accentual patterns, the question of whether learners can acquire new prosodic patterns across the life span arises. Acquisition of English stress by early and late Spanish–English and Korean–English bilinguals was investigated. In a production task, two-syllable nonwords were produced in noun and verb sentence frames. In a perception task, preference for first or last syllable stress on the nonwords was indicated. Also, real words that were phonologically similar to the nonwords were collected. Logistic regression analyses and ANOVAs were conducted to determine the effect of three factors (syllable structure, lexical class, and stress patterns of phonologically similar words) on the production and perception responses. In all three groups, stress patterns of phonologically similar real words predicted stress on nonwords. For the two other factors, early bilinguals patterned similarly to the native-English participants. Late Spanish–English bilinguals demonstrated less learning of stress patterns based on syllabic structure, and late Korean–English bilinguals demonstrated less learning of stress patterns based on lexical class than native-English speakers. Thus, compared to native speakers, late bilinguals’ ability to abstract stress patterns is reduced and affected by the first language. [Work supported by NIH.]
Language preference in monolingual and bilingual infants
Authors: Valji Ayasha , Polka Linda
Published: September 2013

Previous research shows that infants being raised in single-language families have some basic language discrimination abilities at birth, that these skills improve over the first 6 months of life, and that infants are attending to the rhythmic properties of language to perform these skills. Research has also revealed that newborns and older babies from monolingual families prefer listening to their native language over an unfamiliar language. Data on language discrimination and preference in bilingual infants is very limited but is necessary to determine if the patterns and rate of bilingual language development parallel those of monolingual development, or if exposure to more than one language modifies developmental patterns. The present study addresses this issue by comparing language preference in monolingual English, monolingual French, and bilingual English–French infants between 3 and 10 months of age. Infant preference to listen to passages in three rhythmically different languages (English, French, Japanese) was assessed using a visual fixation procedure. Passages were produced by three female native speakers of each language. Findings will show how native language preference is affected by age and language experience in infants who experience monolingual and bilingual language exposure.
The importance of perceived self-motion in experiencing convincing virtual acoustic rendering
Authors: Martens William L.
Published: September 2013

One factor that makes a virtual acoustic environment more convincing is the capacity to present information that enables a listener to answer questions about the geometry of the acoustical space in which they are immersed. This paper reviews the results of several studies in which virtual sound sources were presented to listeners via a loudspeaker array located in an anechoic chamber, and asked about details such as the location of a missing wall in a simulated rectangular room, and whether or not a reduction in the loudness of a virtual source was due to the interposition of a virtual wall between source and listener. When a listener was unaware of changes in the virtual listening position, such questions were difficult to answer; however, when listeners were informed of their path through the environment via computer graphic animation, performance improved significantly. The results of these perceptual experiments suggest that perceived self-motion may be an important determinant of how convincing virtual acoustic rendering may be. The identity of the sound source itself was also found to have a substantial impact, since listeners reported self-motion more often when presented with sound sources that were judged less likely to be in motion.
A binaural Web-based tour of the acoustics of Troy Music Hall
Authors: Torres Rendell R. , Cooney James , Shimizu Yasushi
Published: September 2013

For classical music to become more widely enjoyed, it must sound exciting. We hypothesize that if people could hear examples of truly exciting acoustics, classical music would be perceived less as a rarefied delicacy and more as a viscerally engaging listening experience. The Troy Savings Bank Music Hall in Troy, New York, is a legendary 1200-seat concert hall famous for its acoustics. Such landmarks are commonly documented architecturally but with few attempts to document their acoustics in a way that it is listenable. Thus, the goal is to capture and sonically disseminate the hall’s acoustics through a Web-based acoustical tour, where one can click on various seats to hear binaural auralizations of different instruments and see corresponding views of the stage. The hope is that these auralizations will not only sonically document the acoustics of the hall but also tantalize even geographically distant listeners with binaural samples of how exciting music can be in excellent acoustics. The fun and challenges of devising (let alone standardizing) such an auralization-based system of documentation will be discussed, and a demonstration given. This process can be applied to other historically and acoustically significant spaces. [Work supported by the National Endowment for the Arts.]
An evaluation of differences due to changing source directivity in room acoustic computer modeling
Authors: Vigeant Michelle C. , Wang Lily M.
Published: September 2013

This project examines the effects of changing source directivity in room acoustic computer models on objective parameters and subjective perception. Acoustic parameters and auralizations calculated from omnidirectional versus directional sources were compared. Three realistic directional sources were used, measured in a limited number of octave bands from a piano, singing voice, and violin. A highly directional source that beams only within a sixteenth-tant of a sphere was also tested. Objectively, there were differences of 5% or more in reverberation time (RT) between the realistic directional and omnidirectional sources. Between the beaming directional and omnidirectional sources, differences in clarity were close to the just-noticeable-difference (jnd) criterion of 1 dB. Subjectively, participants had great difficulty distinguishing between the realistic and omnidirectional sources; very few could discern the differences in RTs. However, a larger percentage (32% vs 20%) could differentiate between the beaming and omnidirectional sources, as well as the respective differences in clarity. Further studies of the objective results from different beaming sources have been pursued. The direction of the beaming source in the room is changed, as well as the beamwidth. The objective results are analyzed to determine if differences fall within the jnd of sound-pressure level, RT, and clarity.
Physical and subjective study of randomized sound scattering through geometrical acoustic simulation
Authors: Wang Weifang , Torres Rendell R.
Published: September 2013

Sound scattering is one of the most important phenomena to consider for accurate and fine detailed calculation in both room acoustic design and simulation. Up to now much research work has been done on sound scattering measurement and design and calculation, but how it affects or is relevant to our perception still remains unknown to us. The aim of this research is just trying to find out how randomized sound scattering changes affect our perception and what kind of problems still exist with the current research method based on geometrical acoustic simulation. This research has been carried out with psychoacoustic experiments and advanced time-frequency analysis based on geometric acoustic simulation and binaural signal synthesis. Statistical conclusion on effects of sound scattering change and corresponding visual representation would be given thereafter.
Passive tracking of multiple diving sperm whales using single hydrophones at two mobile locations
Authors: Bahl Rajendar , Nakatani Takeshi , Ura Tamaki , Kojima Junichi , Fukuchi Tetsuo , Sakata Masao , Nose Yoshiaki , Ura Junya , Mori Kyoichi , Sugimatsu Harumi , Yanagisawa Masao , Suzuki Hideyuki
Published: September 2013

A simple method using only two hydrophones, each loosely deployed from separate mobile platforms, has been developed to simultaneously track several vocalizing sperm whales. The separation distance of several hundred meters between the hydrophones implies that a particular whale could present vastly different beam orientations towards them, thus precluding use of any specific relationship between the click signal levels at the two locations for the purpose of whale localization. This method utilizes time-of-arrival of the direct clicks and their surface reflections and matches them at the two hydrophone locations. Whales are segregated on the basis of the set of observed time delays. Click parameters such as interpulse interval and average click frequency are proposed to be used as secondary data for the purpose of track refinement. Depth profile of the whales is obtained independent of the separation distance between the two hydrophones. However, knowledge of the separation distance between the hydrophones provides the 3D coordinates of the whales within a left–right ambiguity. Whale tracks have been obtained using actual data collected off Ogasawara Islands in Japan. These results demonstrate the utility of this method for studying the bioacoustics and behavior of deep diving sperm whales.
The impact of observer dynamics on sonar perception
Authors: Rikoski Richard J.
Published: September 2013

The minimum information necessary for a moving observer to track objects depends on body dynamics, sensor design, sensor configuration, and environmental perturbations. This paper will present governing equations relating sonar measurements to 6 DOF dynamics, and eight nondimensional parameters describing the transitions between various regimes. Using nondimensional analysis, it will be shown that to minimize second-order effects, an observer should increase its ping rate as it approaches a target. Bats have been observed to increase their ping rate as they approach a target [Altringham, Bats: Biology and Behavior (1996)]. Alternatively, an observer might use a target’s angular rate to predict second-order range effects. This requires the angular rate to become observable prior to second-order range effects becoming observable. This yields a design constraint relating velocity, ping rate, and aperture, but not wavelength. Based on this constraint, it appears some marine mammals could track objects in the second-order regime [Au, The Sonar of Dolphins (1993)]. [Work supported by ONR.]
Van Holliday—A role model for leadership in fisheries acoustics
Authors: Karp William A.
Published: September 2013

Van Holliday completed his Ph.D. dissertation, entitled ‘‘Resonance and Doppler Structure from Pelagic Fish Schools,’’ in 1972. He soon published two journal articles based on this research, marking the first steps in a long, distinguished and ongoing contribution to fisheries science. He has published extensively to document his acoustic research on marine life, covering the size spectrum from plankton to marine mammals. This entire body of work is of interest to fisheries biologists who strive to understand the dynamics of populations at all trophic levels to help them better understand the fish populations they study. From this perspective, his advances in acoustic methods, technologies, and instrumentation, and his extensive biological and ecological research should all be considered important contributions to fisheries science. Trained as a physicist, his unique ability to transcend the barriers between physical and biological scientists has been elemental to his success. We recognize Van Holliday for his groundbreaking acoustic research on fish and other forms of marine life, and his scientific and technical excellence. We also recognize Van for his leadership, encouragement, mentoring, and support of colleagues and young scientists, and the vision and focus that he continues to bring to the field of fisheries acoustics worldwide.
Classification of bioabsorption lines at low frequencies: The Van Holliday connection
Authors: Diachok Orest , Wales Stephen , Smith Paul
Published: September 2013

We will describe preliminary results of the second Bioacoustic Absorption Spectroscopy experiment in the Santa Barbara Channel (SBC), BAS II, which was designed to measure the effects of bioabsorptivity on transmission loss (TL) at frequencies between 0.25 and 6 kHz between an ultrabroadband source and a 16-element vertical receiving array. A fisheries echo sounder and trawls provided bioacoustic parameters. Colocated cores and chirp sonar provided geoacoustic parameters (Turgut, unpublished). Temporal changes in temperature structure were measured with three orthogonal thermistor strings. Highest losses were observed at night when fish were dispersed, and at the average depth of the absorption layer, 13 m, in accord with echo-sounder data and simulations. Absorption lines were evident at the resonance frequencies of 15-cm sardines (1.1 kHz) and 11-cm anchovies (1.8 kHz), in accord with trawls, and 20-cm jack mackerel (0.7 kHz), a species known to inhabit the SBC. This classification is consistent with Holliday’s (1972) backscattering measurements of the resonance frequency of jack mackerel (samples collected by Purse Seiner corroborated his classification). Frequencies of absorption lines changed in accord with depth changes at twilight. [Work supported by the ONR and the Southwest Fisheries Science Center.]
2D focal-field aberration dependence on time/phase screen position and correlation lengths
Authors: Näsholm Sven Peter
Published: September 2013

For high-frequency annular array transducers used in medical ultrasound imaging, aberrations due to tissue and body wall have a significant effect on energy transfer from the main lobe to the sidelobes of the acoustic field: that is, the aberrations make the total sidelobe level increase. This effect makes the ultrasound image poor when imaging heterogeneous organs. This study performs an analysis of the focal-field quality as a function of time/phase screen z position and time/phase screen correlation length. It establishes some rules of thumb which indicate when the focal-field sidelobe energy is at its highest. It also introduces a simple screen-scaling model which is useful as long as the screen position is not closer to the focus than a certain limit distance. The scaling model allows the real screen at a depth z=zscreen to be treated as a scaled screen at the position z=ztransd. 2D sound fields after 3D propagation from the annular arrays to the focal plane have been simulated using an angular spectrum method. The aberrators are represented by amplitude and phase/time screens.
High-resolution ultrasonic brain imaging: Noninvasive adaptive focusing based on twin arrays
Authors: Vignon Francois , Aubry Jean-Francois , Tanter Michael , Fink Mathias
Published: September 2013

Ultrasonic imaging systems assume a constant acoustic velocity in human tissues in the beamforming process. However, in the case of brain imaging, strong skull aberrations induce a displacement of the focal stain, a spreading in the main lobe, and an increase in the sidelobes level. This limits considerably ultrasonic brain imaging applications. It has been shown that a very accurate focusing could be achieved through a human skull by using an inverse filter technique. This method, based on a set of acoustic sensors located inside the brain, demonstrated invasively that it was possible to achieve high-resolution brain imaging. A noninvasive ultrasonic method is presented. It is based on two arrays located on each side of the head. Each array focuses on the other one to deduce the aberrations induced by the skull bone. Once the effect of the skull bone in front of each array is extracted, the wavefronts are corrected and emitted. This noninvasive technique restores the position of the focal stain and lowers the secondary lobe level up to 15 dB compared to a cylindrical focusing.
Optical mapping of the acoustic output of a focused transducer
Authors: Huber Robert D. , Chinn Diane J. , Chambers David H.
Published: September 2013

A Michelson interferometer is used to map the ultrasonic displacement of the lens at the end of a delay rod of a 50-MHz immersion transducer. The purpose of mapping the displacement is to provide a source function to a model that predicts the ultrasonic propagation in, and interaction with, various materials. The output of the Michelson interferometer can be calibrated, and then used to determine the displacement of the transducer lens surface moving at ultrasonic frequencies. Using the interferometer, the displacement of the transducer lens is measured at discrete points along its surface. This displacement map then provides the ultrasound propagation model with the actual source function. Direct comparison between a model with a simulated source function and experimentally obtained data is presented. [Work performed under auspices of the U.S. Department of Energy by the Lawrence Livermore National Laboratory under Contract No. W-7405-ENG-48.]
Audio demodulation of radiation pressure from modulated ultrasound
Authors: Toda Minoru
Published: September 2013

Parametric arrays produce audible sound from the audio frequency modulation of high-intensity ultrasound as a result of nonlinear propagation. This paper presents observations of the audible sound resulting from modulated radiation pressure. Audio signals due to the parametric array effect depend strongly on the square of the modulation frequency. It is often shown that the low-frequency region shows a flat frequency response, although it has not been clarified whether this is related to the system noise floor, modulated radiation pressure, or microphone nonlinearity. In this investigation, microphone nonlinearity was found to be very strong at short distances unless acoustic filtering was used. A novel low-pass acoustic filter (passes less than 10 kHz) was constructed using four layers of polyethylene spaced at 4 mm. Using this scheme, the ultrasonic carrier was attenuated and microphone nonlinearity was reduced by six orders of magnitude. Modulated radiation pressure was successfully observed at distances of 1 to 3 m. The observed audio signal showed a flat frequency response and agreed with theoretical predictions for modulated radiation pressure. The reproduced audio signal from radiation pressure appears in a lower frequency region of parametric array audio systems, and the effect should be taken into the system design.
Philosophical and cultural perspectives on acoustics in Vedic Hinduism
Authors: Prasad M. G.
Published: September 2013

Acoustics plays a very important multi-faceted role in Vedic Hinduism. Vedas, that is an infinitely large collection of chants (mantras) in ancient Sanskrit language, form the foundational literature of Vedic Hinduism. The Vedic chants have specific acoustical qualities and intonations. The Vedic literature describes the various aspects of acoustics, namely, philosophical, spiritual, and cultural. The use of sounds from conch-shell, bells, cymbal in addition to the Vedic chants in rituals shows the spiritual aspects. Vedic literature discusses the role of sound in the philosophical understanding of our world. Music, both vocal and instrumental, plays an important role in the cultural aspects of Vedic Hinduism. It can be seen that certain musical instruments such as ‘‘mridangam,’’ a percussion drum, reflect scientific principles underlying in their design. This paper presents an overview of the various important and interesting roles of acoustics in Vedic Hinduism.
Ocean acoustics at BBN and beyond
Authors: Dyer Ira
Published: September 2013

Earlier known exclusively as underwater acoustics, ocean acoustics was pursued almost from BBN’s beginning, the firm created by Richard Bolt and Leo Beranek. Ship noise, including that of submarines, and also sonar detection performance are perhaps still classified as underwater acoustics, while sound propagation and noise in the ocean have come to be classified as ocean acoustics. Given its creators, it is no surprise that contributions at BBN to ocean acoustics to about 1970 were based on fundamental concepts in architectural acoustics. These are in essence a set of geometrical ideas within which complicated multi-mode waves propagating in rooms can be reduced to simple theoretical and measurable aggregates expressing the mean-square wave motion. Thus, ray-averaged theories of propagation, wave coherence, and noise in the ocean were developed and used at BBN, as they were elsewhere, and are still in use today. By about 1970 it became clear that improved measurement tools, and increased understanding of the ocean state, including the bottom, could be exploited by theories and measurements of the phase as well as the mean-square motion. This story is traced from the perspective of those at BBN in the early years, to the present state of ocean acoustics.
Numerical simulation of flow-excited cavity tones
Authors: Zoccola Paul J. , Slomski Joseph F. , Farabee Theodore M.
Published: September 2013

The objective was to develop a numerical model for investigating the effect of obstructions in the opening on the frequency and amplitude of flow-excited cavity pressure fluctuations. A hybrid Reynolds-averaged Navier–Stokes/large eddy simulation (RANS/LES) method was used. The RANS/LES method ensures that important turbulence scales outside of the boundary layer are resolved, while permitting more economical RANS modeling of the smaller turbulent scales immediately adjacent to walls. Solutions were obtained at the speed where the cavity Helmholtz resonance was excited and at a speed well below resonance. A solution was also obtained where the cavity opening was partially obstructed. Results were compared to experimental data obtained for the same configuration. In all cases, the frequency of the shear layer oscillations was accurately predicted. Resonant cases also showed excellent agreement on the amplitude of the first harmonic. Some initial difficulties in predicting the amplitude in the nonresonant case are attributed to excessive dissipation in the LES calculations. Nonresonant cases are being resimulated using a less dissipative advective scheme and SGS turbulence model. A comparison of some flow field results showed reasonable agreement in certain cases.
Fluid-structure interaction in fast breeder reactors
Authors: Mitra A. A. , Manik D. N. , Chellapandi P. A.
Published: September 2013

A finite element model for the seismic analysis of a scaled down model of Fast breeder reactor (FBR) main vessel is proposed to be established. The reactor vessel, which is a large shell structure with a relatively thin wall, contains a large volume of sodium coolant. Therefore, the fluid structure interaction effects must be taken into account in the seismic design. As part of studying fluid-structure interaction, the fundamental frequency of vibration of a circular cylindrical shell partially filled with a liquid has been estimated using Rayleigh’s method. The bulging and sloshing frequencies of the first four modes of the aforementioned system have been estimated using the Rayleigh–Ritz method. The finite element formulation of the axisymmetric fluid element with Fourier option (required due to seismic loading) is also presented.
Auditory-evoked magnetic fields in relation to the interaural cross correlation
Authors: Soeta Yoshiharu , Nakagawa Seiji , Tonoike Mitsuo , Hotehama Takuya , Ando Yoichi
Published: September 2013

Noninvasive measurements utilizing magnetoencephalography (MEG) have been used to study how sound stimulus features are represented in the human brain. These measurements have successfully revealed how, for example, tone frequency, periodicity, and intensity are encoded. Here, the auditory-evoked magnetic fields in change of the magnitude of the interaural cross correlation (IACC) were analyzed. The IACC of the stimuli was controlled by mixing two independent bandpass noises in appropriate ratios. The auditory stimuli were binaurally delivered through silicon tubes and earpieces inserted into the ear canals. All source signals had the same sound-pressure level. Nine volunteers with normal hearing took part in this study. The auditory-evoked fields were recorded using a neuromagnetometer in a magnetically shielded room. Combinations of a reference stimulus (IACC=1.0) and test stimuli (IACC=0.2,0.6,0.85) were presented alternately at a constant 0.5-s interstimulus interval, and the MEGs were recorded and averaged more than 50 times. The results showed that the peak amplitude of N1m, which was found above left and right temporal lobes around 100 ms after the stimulus onset, significantly decreased with increasing IACC. The N1m latencies were not affected by IACC.
Acoustic emission analysis of shuttle thermal protection system
Authors: Lane John , Hooker Jeffery , Immer Christopher , Walker James
Published: September 2013

Acoustic emission (AE) signals generated from projectile impacts on reinforced and advanced carbon/carbon (RCC and ACC) panels, fired from a compressed-gas gun, identify the type and severity of damage sustained by the target. This type of testing is vital in providing the required return to flight (RTF) data needed to ensure continued and safe operation of NASAs Space Shuttle fleet. Conventional AE analysis techniques require time domain processing of impulse data, along with amplitude distribution analysis. It is well known that identical source excitations can produce a wide range of AE signal amplitudes. In order to satisfy RTF goals, it is necessary to identify impact energy levels above and below damage thresholds. Spectral analysis techniques involving joint time frequency analysis (JTFA) are used to reinforce time domain AE analysis. JTFA analysis of the AE signals consists of short-time Fourier transforms (STFT) and the Huang–Hilbert transform (HHT). The HHT provides a very good measure of the instantaneous frequency of impulse events dominated by a single component. Identifying failure modes and cracking of fibers from flexural and/or extensional mode acoustic signals will help support in-flight as well as postflight impact analysis.
The elastic shell T-matrix theory evaluated
Authors: Werby Michael , Uberall H.
Published: September 2013

The T-matrix method initiated by Waterman was extended in a clever paper by Peterson and the Varadans in 1980 to the complicated problem of elongated elastic shells. There have been some questions on whether the method converges for thin shells due to the impression that one must be able to inscribe a spherical surface in the annular region of the shell. The method may be derived by making use of several of the constraining equations that arise naturally and we show that the expression derived in 1980 is generally correct at least for objects with mirror symmetry. We present some details of the theoretical development with some calculations.
The stability of locus equation slopes across stop consonant voicing/aspiration
Authors: Sussman Harvey M. , Modarresi Golnaz
Published: September 2013

The consistency of locus equation slopes as phonetic descriptors of stop place in CV sequences across voiced and voiceless aspirated stops was explored in the speech of five male speakers of American English and two male speakers of Persian. Using traditional locus equation measurement sites for F2 onsets, voiceless labial and coronal stops had significantly lower locus equation slopes relative to their voiced counterparts, whereas velars failed to show voicing differences. When locus equations were derived using F2 onsets for voiced stops that were measured closer to the stop release burst, comparable to the protocol for measuring voiceless aspirated stops, no significant effects of voicing/aspiration on locus equation slopes were observed. This methodological factor, rather than an underlying phonetic-based explanation, provides a reasonable account for the observed flatter locus equation slopes of voiceless labial and coronal stops relative to voiced cognates reported in previous studies [Molis et al., J. Acoust. Soc. Am. 95, 2925 (1994); O. Engstrand and B. Lindblom, PHONUM 4, 101–104]. [Work supported by NIH.]
One-hand control of a speech synthesizer
Authors: Cheyne Harold A. , Beaudoin Robert E. , von Wiegand Thomas E. , Stevens Kenneth N. , Zurek Patrick M.
Published: September 2013

The long-term objective of this research is the development of a one-hand-controlled speech synthesizer, to give laryngectomees and other speech-impaired persons a means of producing higher-quality speech with less effort than currently available methods such as an electrolarynx or a text-to-speech system. To demonstrate the feasibility of a one-hand-controlled speech synthesizer, a system was constructed using a hand-held device similar to a pen connected to an articulated arm for measuring six degrees of freedom (three Cartesian and three rotational dimensions) as the user interface to an HLsyn-based speech synthesizer. Through this interface, the user controls parameters for the first three formants, pitch, subglottal pressure, and glottal area. Parameter control was introduced progressively in that order to four participants who underwent training to produce synthesized speech composed of a subset of English phonemes: vowels, semivowels, diphthongs, /h/, and the glottal stop. The complexity of the synthesized speech targets also grew from monosyllabic utterances to short phrases over the training. After training, a separate group of four listeners compared the naturalness and intelligibility of the synthesized speech to the same utterances produced by the participants with a text-to-speech system. [Work supported by NIDCD Grant Number R43 DC006134-01.]
Text-to-phonemic transcription and parsing into mono-syllables of English text
Authors: Jusgir Mullick Yugal , Agrawal S. S. , Tayal Smita , Goswami Manisha
Published: September 2013

The present paper describes a program that converts the English text (entered through the normal computer keyboard) into its phonemic representation and then parses it into mono-syllables. For every letter a set of context based rules is defined in lexical order. A default rule is also defined separately for each letter. Beginning from the first letter of the word the rules are checked and the most appropriate rule is applied on the letter to find its actual orthographic representation. If no matching rule is found, then the default rule is applied. Current rule sets the next position to be analyzed. Proceeding in the same manner orthographic representation for each word can be found. For example, ‘‘reading’’ is represented as ‘‘rEdiNX’’ by applying the following rules: r→r move 1 position ahead ead→Ed move 3 position ahead i→i move 1 position ahead ng→NX move 2 position ahead, i.e., end of word. The phonemic representations obtained from the above procedure are parsed to get mono-syllabic representation for various combinations such as CVC, CVCC, CV, CVCVC, etc. For example, the above phonemic representation will be parsed as rEdiNX-→ /rE/ /diNX/. This study is a part of developing TTS for Indian English.
Representational specificity of within-category phonetic variation in the mental lexicon
Authors: Ju Min , Luce Paul A.
Published: September 2013

This study examines whether within-category variation in voice onset time (VOT) is encoded in long-term memory and affects subsequent word recognition, and whether these effects are modulated by the degree of lexical discriminability. Four long-term repetition-priming experiments were conducted using words containing word-initial voiceless stops varying in VOT. The magnitude of priming was compared between same and different VOT conditions in words with voiced counterparts (pat/bat) and words without voiced counterparts (cow/*gow), and in words with high-frequency counterparts (clue/glue) and words with low-frequency counterparts (cab/gab). If veridical representations of each episode are preserved in memory, variation in VOT should have demonstrable effects on the magnitude of priming. However, if within-category variation is discarded and form-based representations are abstract, variation in VOT should not mediate priming. Further, if lexical discriminability modulates the degree of encoding of within-category variation, words with counterparts and words with high-frequency counterparts should show larger specificity effects than words without counterparts and words with low-frequency counterparts. Implications of these results for the specificity and abstractness of phonetic representations in long-term memory will be discussed.
Time domain beamforming ASIC for a handheld bistatic imaging sonar system
Authors: Chiang Alice M. , Broadstone Steven R. , Impagliazzo John M.
Published: September 2013

A high-resolution, handheld imaging sonar system has been developed by Teratech Corporation for the U.S. Navy. This is a 192-channel, dual-frequency bistatic sonar for Navy divers performing search and survey missions for underwater explosives. The goal is to provide the most compact and energy-efficient imaging system for the divers. The low power and small volume are a result of the development of Teratech’s Charge Domain Processing (CDP) technology. This technology has led to the development of a low-power 64-channel beamformer chip. As a result, only three beamformer chips are needed for the 192-element array. Until now, implementation of small, low-power sonar systems containing this many elements and forming enough beams to create an image was considered impossible. Test results and acoustic images obtained in Teratech’s acoustic test tank will be presented. [Work sponsored by ONR and OSD Small Business Innovative Research Program, Program Manager, Mr. Bruce Johnson, Naval Explosive Ordnance Disposal Technology Division.]
Environmental uncertainty in modeling of shallow-water reverberation
Authors: Yudichak T. W. , Knobles D. P.
Published: September 2013

Simulated monostatic shallow-water reverberation is produced by a broadband model that accounts for propagation and scattering in a waveguide that is horizontally stratified on average, but subject to slightly rough interfaces and small, random spatial fluctuations in density and sound speed. This model has been used to infer parameters characterizing these inhomogeneities (scattering parameters) from experimental data, assuming a specific background geoacoustic profile. In realistic situations, however, the background environment may either not be known with precision or may be too variable to admit a range-independent characterization. It is even possible that several geoacoustically distinct alternative sets of environmental parameters are plausible. This may occur, for instance, when geoacoustic inversion is used to determine a background profile. In this presentation, the effects of environmental uncertainties, including the existence of alternative geoacoustic profiles, on scattering parameters inferred from reverberation data are examined. [Work supported by ONR.]
Propagation modeling for sperm whale acoustic clicks in the northern Gulf of Mexico
Authors: Sidorovskaia Natalia A. , Udovydchenkov Ilya A. , Rypina Irina I. , Ioup George E. , Ioup Juliette W. , Caruthers Jerald W. , Newcomb Joal , Fisher Robert
Published: September 2013

Simulations of acoustic broadband (500–6000 Hz) pulse propagation in the northern Gulf of Mexico, based on environmental data collected as a part of the Littoral Acoustic Demonstration Center (LADC) experiments in the summers of 2001 and 2002, are presented. The results of the modeling support the hypothesis that consistent spectrogram interference patterns observed in the LADC marine mammal phonation data cannot be explained by the propagation effects for temporal analysis windows corresponding to the duration of an animal click, and may be due to a uniqueness of an individual animal phonation apparatus. The utilization of simulation data for the development of an animal tracking algorithm based on the acoustic recordings of a single bottom-moored hydrophone is discussed. The identification of the bottom and surface reflected clicks from the same animal is attempted. The critical ranges for listening to a deep-water forging animal by a surface receiving system are estimated. [Research supported by ONR.]
Seasonal variation in the distribution of Calanus finmarchicus and its predators observed through multifrequency acoustics in the Irminger Sea
Authors: Fielding Sophie , Mustard Alexander T. , Anderson Cairistiona I. H. , Brierley Andrew S. , Heath Michael R.
Published: September 2013

The seasonal, and in particular, winter distribution of Calanus finmarchicus and its predators were investigated using multifrequency (38–600 kHz) acoustic backscatter measurements in the Irminger Sea, North Atlantic, as part of Marine Productivity, a UK contribution to GLOBEC. The distribution of Calanus, which over-winters deeper than 500 m, well below the acoustic penetration depth of a frequency suitable for detecting targets of approximately 0.2 cm from the surface, was examined using a 600-kHz RDI Acoustic Doppler Current Profiler (ADCP) mounted on a lowered CTD frame. A net system, for species information, and an optical plankton counter (OPC), for numerical abundance, was deployed at each station to ground-truth the 600-kHz acoustic backscatter data. Model-predicted profiles of acoustic backscatter, calculated using OPC derived Calanus abundances and a fluid-filled cylinder acoustic scattering model, were consistent with the observed 600-kHz profiles. Calanus predators, euphausiids, e.g., Meganyctiphanes norvegica and fish, e.g., Myctophids, were observed using a surface towed Simrad EK500 multifrequency echosounder. Seasonal variations in the depth of sound scattering layers at each frequency were observed within the Irminger Sea, which suggests that the Calanus predators may be deepening their winter depth to coincide with the maximum over-wintering Calanus abundances.
Marine Mammal Active Sonar Test 2004 (MAST 2004)
Authors: Stein Peter J. , Vandiver Amy , Edelson Geoffrey S. , Frankel Adam S. , Clark Christopher W.
Published: September 2013

The Marine Mammal Active Sonar Test was conducted in January 2004 off the central California coast during the gray whale migration. The purpose of the test was to collect data to significantly advance active sonar detection, classification, and tracking of marine mammals out to ranges of 1 mile. The R/V New Horizon was moored in the migration path. Two different sonar systems operating between 210 and 220 dB were deployed off the vessel, the IMAPS phased array sonar system that operates from 20–30 kHz and the MAST mechanical system that uses rotating parabolic transducers operating from 30 to 40 kHz. Marine mammal observers were deployed on the bluffs overlooking the experiment and aboard the New Horizon. The observers tracked the whales using electronic theodelites, providing ground truth for the sonar systems. They also looked for any severe reactions from the animals, and called for a shutdown if any marine mammals were observed within 100 m of the sonar. Here, we discuss the experiment and the results to date, including any reaction of the whales to the sonar system. We will also touch on the legal battle to conduct the experiment, and lessons learned.
In vitro characterization of echogenic liposomes by acoustic scattering at 3.5–15.0 MHz
Authors: Porter Tyrone M. , Holland Christy K. , Datta Saurabh , Hwang Shaoling , MacDonald Robert C. , McPherson David D.
Published: September 2013

Echogenic liposomes (ELIP) are phospholipid vesicles that are being developed as ultrasound contrast agents and as vehicles for drug delivery. These particles, when conjugated with antibodies or peptides, can be used for targeted diagnostic imaging and therapy. Evaluating the acoustic properties of ELIP will allow for optimization of its utility as an ultrasound contrast agent. The diameter of the liposomes ranges from 0.25–10.0 μm. In order to measure the backscattering coefficient in vitro, the backscattered power was compared to that reflected from a perfect reflector, a planar air–water interface. The backscatter coefficient and attenuation of ELIP were evaluated as a function of concentration (0.8–9.9×108/ml) and frequency (3.5–15.0 MHz). By comparing the values of measured backscatter coefficient to a theoretical model that treats the gas within the liposomes as a free air bubble, a size estimate of the encapsulated gas is provided. Finally, calculation of the scattering to attenuation ratio (STAR) gives a value with which to evaluate the efficacy of ELIP as a contrast agent in cardiovascular ultrasound imaging. The backscatter coefficient shows promise as a sensitive method for determining whether the liposomes are left intact or if they are destroyed during imaging.
Acoustical consulting—Reflections on a challenging career
Authors: Braslau David
Published: September 2013

The acoustical consulting profession can be entered in a number of ways. The most direct approach is to obtain a degree in acoustics and join a large consulting firm immediately after graduation. Acoustical consulting can also be entered indirectly from various fields of engineering or physics which can provide a somewhat broader background. These disciplines might include, for example, structural engineering and structural dynamics, mechanics of materials, dynamic behavior of solids or geophysics. Acoustical consulting specialization can be very broad or very narrow as seen from the National Council of Acoustical Consultants capability listing. As an acoustical consultant, one must address a wide range of problems which provides both the challenges and joys of this profession. Technical capabilities and professional judgment are constantly developed from exposure to these problems and through interaction with other members of the profession. Selected case studies including sound isolation in buildings, noise and vibration from blasting, control of noise from environmental sources, acoustical design of classrooms and performing spaces, and product design demonstrate the variety of challenges faced by an acoustical consultant.
Life as an acoustician in industry, academia, and government service
Authors: Hastings Mardi C.
Published: September 2013

Acoustics is a science that has very broad applications, which affect all different areas of our lives. During the last 20 years, I have combined family with a career as an acoustics engineer in industry, a tenured faculty member at a university and, most recently, a program manager in a government agency. In these positions I have worked in several areas of acoustics, including noise control, structural acoustics, building acoustics, sound quality, physical acoustics, acoustic materials, underwater acoustics, biomedical ultrasound, physiological acoustics, and bioacoustics. Although the fundamental science of sound is the foundation of all these areas, communication of ideas, problems, and solutions varies greatly from industry to academia to government. Thus knowing the science and how to use it are not enough, as communication skills and the ability to adapt them to changing environments are essential for a successful career. In addition to describing life as an acoustician in industry, academia, and government service, I will present several examples of how even though the acoustic fundamentals are the same, how they are communicated could become a disaster or save the day.
The harpsichord in 1929 and the emperor’s new clothes
Authors: Kottick Edward
Published: September 2013

By the end of the 19th century the harpsichord was considered obsolete. Viewed from the vantage point of a century of brilliant advances in piano technology, it was an outworn, outmoded relic of a distasteful past. It was overly delicate in nature; its soundboard was too thin, and thus unstable; its case construction was unsubstantial. Its light, unbushed keyboards were inadequate. Its quaint bird-quill plectra were viewed with disdain, and its sound was thought to be weak and unattractive. Nevertheless, by the year 1929 the harpsichord was enjoying a revival that was at that time in its 40th year, and that revival continues today. If this instrument was considered so inadequate, why has its revival been so successful and long-lasting? All the answers boil down to one word: sound. This paper will explore the contrast of the tonal qualities of the revival harpsichords and the antiques, and the way those qualities changed in response to the shifting tastes of builders, performers, and listeners. Ultimately, changing tastes led to a return to the sound of the classical harpsichord. Embedded in this tale is an important lesson on the dangers of characterizing the tone of any instrument.
The nature of noise in society
Authors: Blomberg Leslie
Published: September 2013

Noise is unique among pollutants. It is, for example, the only pollutant commonly defined in subjective, psychological terms: ‘‘unwanted sound.’’ Ironically, noise experts work almost entirely in objective measures-sound pressure, sound power, Leq, Ldn, etc. This paper suggests that between the science and engineering of acoustics and the psychology of sound perception, in the societal and social context, lies the true nature of noise–its causes and effects. Enriched by contacts with tens of thousands of individuals over the past 8 years, the Noise Pollution Clearinghouse is working to redefine noise in societal terms. In understanding the nature of noise, the concepts of civility, sovereignty, environmental quality, quality of life, and connectedness to others are much more helpful than ‘‘unwanted sound.’’
The effects of removing barriers to hearing protector use
Authors: Stephenson Mark
Published: September 2013

When high level noise exposure is unavoidable, wearing hearing protectors is essential to preventing hearing loss and preserving the quality of ones life. Unfortunately, many people fail to wear hearing protectors when they are exposed to loud noise. Focus groups and surveys conducted by the National Institute for Occupational Safety and Health (NIOSH) have identified a set of barriers frequently cited as reasons for not wearing hearing protection. NIOSH has employed these data to develop a field study designed to address barriers to hearing protector use. Interim results have demonstrated that by applying contemporary health communication theory to focus training messages and methods on specific barriers, it is possible to positively influence attitudes and behaviors associated with hearing protector use. This paper will describe the methods used in this study and discuss the results obtained to date.
Data treatment method to improve the determination of indexes related to the directive 2002/49/EC about environmental noise management
Authors: Cueto Jose Luis , Rivas Silvia , Hernandez Ricardo
Published: September 2013

The European Directive 2002/49/EC defines useful procedures in order to evaluate, by means of indexes, the acoustic pollution affecting urban areas. To apply those methods correctly, it is necessary to get a properly designed acoustic database. Usually the environmental information managed by the laboratories shows a different kind of problem. Nowadays the Acoustic Laboratory of the University of Cadiz (Spain) is very interested in the developing of new data-processing tools. These tools overcome the errors in the calculation of the indexes due to the use of inappropriate databases. We focus not only on the determination of the possible problems, but on the best solutions. We suggest in this paper a simple data treatment method that permits one to reach more accurate indexes in spite of such common problems.