bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of spectral differences on the ability to judge the laterality of a simulated source followed by a simulated echo
Authors: Boomer Joseph B. , Dye Raymond H. , Sheft Stanley , Yost William A.
Published: October 2013

The purpose of this study was to examine listeners’ abilities to lateralize a source click based on interaural difference of time (IDTs) when followed by a spectrally different echo click. The first click was centered at 3000 Hz and the second was centered at 1500, 2000, 3000, 4000, or 5000 Hz. A correlational analysis was carried out to assess the relative weight given to the IDTs of source and echo clicks for echo delays of 8–128 ms. Also measured were proportions correct and proportions of responses predicted from the weights. Listeners were instructed to indicate the laterality of the source click. The IDTs of the source and echo clicks were selected independently from Gaussian distributions (=0 s, =100 s). When the second click had energy in a spectral region above that of the first, source weights and proportions correct were higher than when the spectral region of the second was lower than the first click. For some observers, this low-frequency dominance was evident for echo delays as long as 128 ms. The effect of echo frequency was constant across all echo delays, although source weights and proportions correct were highest at an echo delay of 8 ms.
Acoustic characteristics of clearly produced fricatives
Authors: Maniwa Kazumi , Jongman Allard , Wade Travis
Published: October 2013

Research suggests that speakers can adopt a speaking style that allows them to be understood more easily when confronted with difficult communication situations, but few studies have examined the acoustic properties of clearly produced consonants in detail. This study attempts to characterize the type and magnitude of adaptations in the clear production of English fricatives in a carefully controlled range of communication situations. Ten female and ten male talkers produced nonsense syllables containing the eight English fricatives in VCV contexts, both in a conversational style and in a clear style (elicited by means of feedback consisting of simulated recognition errors received from an interactive computer program). Acoustic measurements were taken for spectral, amplitudinal, and temporal properties known to influence fricative recognition. Results illustrate that (1) there were some consistent overall clear speech effects, several of which (consonant duration, spectral peak location, spectral moments) were consistent with previous findings and a few (notably consonant-to-vowel intensity ratio) which were not; (2) ‘‘contrastive’’ differences related to eliciting prompts were observed in a few key comparisons; and (3) talkers differed widely in the types and magnitude of acoustic modifications.
Multichannel near-array corrections for short-period teleseismic data
Authors: Campman Xander , Rondenay Stephane
Published: October 2013

The increased availability of data from broadband and short-period seismometer arrays has stimulated the development of multichannel high-resolution imaging algorithms for scattered teleseismic waves. One of the main factors limiting the resolution of teleseismic images is the interference from unwanted phases at higher frequencies (0.3–1.5 Hz). These unwanted phases are generally associated to scattering at near-surface features. We describe initial results from a multichannel inversion-based method designed to suppress scattered waves from surface topography. Such an approach is possible because the dense spatial sampling of short-period arrays allows us to sample these phases well enough to characterize them. Using a subset of the data, we first estimate a model for the distribution of near-surface scatterers. Next, we predict scattered waves in the entire data set using this scatterer distribution model. Both the inversion and prediction steps are based on an integral representation of the scattered-wave field which takes into account the near-field character of body-to-surface wave scattering. Finally, we subtract the predicted scattered waves from the entire data set. Data from the LARSE93 experiment are used to illustrate and validate the present algorithm.
Time domain modeling of acoustic Doppler from 2-D, developing, and swell-contaminated seas displaying a bimodal azimuthal dependence
Authors: Keiffer Richard
Published: October 2013

The typical sea-surface acoustic scattering experiment is often modeled invoking an environment and measurement scenario containing a number of idealizations. Almost universal is the assumption that the rough pressure-release air/sea boundary can be described using a roughness spectrum that belongs to spatially uniform, fully developed seas. Often this roughness spectrum is assumed to have a simple cosine-squared or some other canonical azimuthal dependence. The air/sea boundary is assumed to be an overly homogeneous isospeed ocean and the source and receiver are assumed stationary or in uniform rectilinear motion. Because the data collected at sea and the results from numerical simulations are often compared in order to infer the acoustic attributes of bubbles and bubble clouds, it is important to have a good understanding of the limitations that these common idealizations impose on the data/model comparison. In this paper, a newly developed and tested time domain model for acoustic scattering from moving 2-D surfaces [J. Acoust. Soc. Am. 118(3), 1283–1299 (2005)] is used to examine the implications that wave growth, swell contamination of a bimodal azimuthal dependence, and near-surface upward refraction have on the Doppler of acoustic signals backscattered from the sea surface. [Work supported by ONR/NRL.]
Sparrows swarm and sing—a sonic collaboration
Authors: Cohn Eli D. , Mallory Robert M. , Case Alexander U.
Published: October 2013

Untitled Number 3 was written and performed by the Massachusetts-based sextet, Sparrows Swarm & Sing. The work combines orchestral string instruments and percussion, distorted guitars, rock drums, voices without words, and an array of handmade noisemakers. The first movement, ‘‘Quartet’’ (recorded live), begins with underlying chimes and noisemakers present throughout the piece. Acoustic cello and violin quietly emerge from the disciplined electric guitar line. Harmony and dissonance evolve into a lush reverberant noise created from each note played in the preceding string passage. The second movement, ‘‘Come on Camaraderie,’’ emerges from the reverberant decay into an uplifting dance song of which the climax is highlighted with a choral vocal line. This immediately propels itself into the brooding and relentless noise of guitar melodies/detunings. The quiet vocal melody introduces the third movement, ’’The Processional.’’ Electric guitar and bass beckon a distant cello melody followed by layers of bowed glockenspiel, cello/violin pizzicato, chimes, and snare drum.
Issues pertaining to the composing of ``minimalist'' loudspeaker music for home theater arrays
Authors: Moulton David
Published: October 2013

Loudspeaker music composed for home theater loudspeaker arrays is subject to a different set of aesthetic principles and production problems than is music (live or otherwise) prepared for concert presentation. Issues of scale, timing, dynamic range, spectral range, sonic materials, reverberance, the treatment of spatial issues, and listener expectations will all be discussed.
Different space conceptions in two electroacoustic compositions: Rojo and human-space-factory
Authors: Tutschku Hans
Published: October 2013

Having used multichannel speaker setups for my electroacoustic compositions since 1989, I have experimented with many approaches to compose different sound-space relationships over the years. In human-space-factory, composed in 1999, the movements of the sounds in space are directly correlated with spectromorphologic changes of the sounds themselves. The composition tends to create distinguishable different spaces, sometimes even simultaneously. Rojo, composed in 2004, evokes the aural image of rituals of different cultures. Voices come from all directions and create a musical happening, surrounding the audience to give the impression that the listener is actually participating in the performance. The paper will outline the different compositional approaches and some technical solutions encountered during the realization of both compositions. Sound examples will be played during the lecture.
The echolocating bat controls the direction and distance of its acoustic gaze
Authors: Moss Cynthia , Ghose Kaushik
Published: October 2013

Adaptive vocal control by echolocating bats may serve to spatially filter acoustic information in a complex environment. It is well documented that FM bats actively adjust the duration of sonar vocalizations to avoid overlap of emissions and echoes. FM bats also control the direction of the sonar beam, which restricts the direction and volume of space sampled by the sonar system. Therefore, the temporal characteristics of the bat’s sonar signals can be used to estimate its window of attention along the range axis, and the sonar beam aim as an index of the direction of its acoustic gaze. Here, we describe a series of studies that investigated adaptive sonar behavior of the big brown bat performing in a variety of echolocation tasks. We used high-speed infrared video to reconstruct the flight path of the bat and its insect prey. An array of ultrasonic microphones recorded the timing and spatial pattern of each sonar emission. Quantitative analyses of the data suggest that the bat’s directional aim and temporal control of sonar signals may reduce information processing demands on its auditory system, enabling adaptive behaviors that must occur rapidly as the animal flies. [Work supported by NIMH and NIBIB.]
How well does a whale hear its own biosonar pulses?
Authors: Supin Alexander Ya. , Nachtigall Paul E. , Breese Marlee
Published: October 2013

During echolocation, whales and dolphins perceive faint echoes shortly after emitting loud outgoing sound pulses. Why do the outgoing sounds not mask the faint echoes? Is it because the sound energy is effectively concentrated in the transmitted sonar beam and isolated from the animal’s own ears? To answer this question, we recorded a false killer whale’s emitted echolocation pulses and auditory-evoked potentials provoked by its pulses and compared them to similar responses produced by external acoustic signals of known intensities. A few thousand of the individual AEP records were sorted according to the spontaneously varied amplitude of the synchronously recorded biosonar pulses. In each of the sorting bins (in 5-dB steps), AEP records were averaged to extract AEPs from the noise. For comparison, AEPs were recorded to external sound pulses with waveforms, spectra, and amplitudes similar to those of the whale’s biosonar pulses. A comparison has shown that, depending on the target presence or absence, the sensitivity of the whale’s hearing to its own transmitted biosonar pulse was 30 to 45 dB lower than might be expected in a free acoustic field
A spike burst coding scheme for environment representation by FM bats
Authors: Peremans Herbert , Fontaine Bertrand
Published: October 2013

All environmental features of interest to bats, i.e., spatial arrangement of reflectors as well as reflector type, are coded into the patterns of spikes that travel up the auditory nerve into the bat’s brain. Realistic scenes containing multiple, closely spaced reflectors give rise to complex echo signals consisting of multiple, highly overlapping filtered copies of the bat’s own vocalization. Some of this filtering is self-induced, i.e., directivity of the bat sonar system, and some of it is beyond the control of the bat, i.e., sound absorption and reflection process. This analysis concentrates on the conspicuous ridges these filter operations give rise to in the time-frequency representation of the echo as produced by the FM bat’s inner ear. Assuming multiple threshold detecting neurons for each frequency channel, it is shown how the time dispersion of the generated spike bursts is linked to the presence and characteristics of these notches. A neural network decoding the spike bursts in terms of notch locations and types is described. After separating the notches due to the HRTF from the reflector generated ones, they are separately interpreted in terms of the environmental features of interest, i.e., target location and target structure. [Work funded by the EC, IST-FET Initiative.]
Coupling between elastic strain and interstitial fluid flow: Ramifications for poroelastic imaging
Authors: Leiderman Ricardo , Barbone Paul E. , Oberai Assad
Published: October 2013

Elastography refers to a host of imaging techniques that enables the quantitative measurement of tissue displacement and strain in vivo. In its most common modality, ultrasound is used to map the displacement, and an inverse problem to find the tissue biomechanical properties results, based on the tissue’s constitutive equation, and the law of conservation of momentum. In most previous applications, the constitutive model for the tissue is assumed to be elastic or viscoelastic. It is well recognized, however, that soft tissues contain both fluid and solid phases. Furthermore, the fluid may flow within and between several different compartments. This paper addresses the question: Can ultrasound be used to image and quantify interstitial fluid flow in soft tissues from spatio-temporal patterns of elastic strain? To answer this, we use the mathematical model of vascularized soft tissue, which includes the effects of fluid flow and the possibility of exchange between fluid compartments in conjunction with finite-element modeling to predict the effects of fluid fluid flow on the spatio-temporal patterns of soft-tissue elastic strain.
Sensitivity of 1-MHz ultrasound compression and shear waves propagating on cortical bone porosity: A numerical study
Authors: Baron Cecile , Talmant Maryline , Laugier Pascal
Published: October 2013

The objective of this study was to describe how the porosity of cortical bone affects ultrasound propagation (wavelength: mm scale). The bulk compression and shear velocities were determined for 40 specimens of human radius using finite-difference computation of transient ultrasound bulk waves in axial and transverse directions. The 3D microstructure of the specimens were obtained using high-resolution synchrotron radiation micro-computed tomography (voxel size =10μm). The pores were filled with a nonviscous fluid and the model assumed the bone material to be elastic and transversely isotropic or isotropic. All bulk wave velocities decreased quasi-linearly with increasing porosity, e.g., typically 28 m/s/%por for the axial compressional wave velocity. For the radial compressional wave velocity, the rate depended on the assumption on the bone material (for isotropy 56 m/s/%por and for transverse isotropy 19 m/s/%por). In case of transversely isotropic bone matrix, cortical bone tended to become more acoustically isotropic when its porosity increases in agreement with previous experimental studies. This study may help to develop more accurate models of cortical bone used to design improved ultrasound devices and to provide guidelines for establishing methods for the ultrasonic determination of bone properties.
Wavelet analysis of active cavitation detector output
Authors: Anguah Kofi A. , Everbach E. Carr
Published: October 2013

Active cavitation detectors (ACDs) have provided useful information concerning the dynamics of microbubbles exposed to intense pulsed ultrasound. In an examination of the effects of nearby solid surfaces on the asymmetrical collapse of bubbles, ACD signals consisting of 60-cycle 30-MHz tone bursts of <0.1 MPa peak negative pressure returned complex echoes for individual bubbles and groups of bubbles. The Gauss-Harmite wavelet transform was used to analyze these signals to differentiate between symmetrical and asymmetrical collapse signatures, with the goal of identifying the percentage of asymmetrical bubble collapses in a cavitation field. [Work supported by NIH R-15 EB004630-01.]
A 3D finite-element method (FEM) of the body of a classical guitar
Authors: Richter Jan
Published: October 2013

A 3D finite-element method (FEM) of a body of a classical guitar is performed. It consists of the rib, back plate, top plate with bridge, soundhole and fan bracing, and wooden block. The idea of this project is to compare the eigenfrequencies of different body shapes and make assumptions about the way the elements of the body influence the sound of a classic guitar. The aim is to calculate the influence of the thickness of the bottom, the amount of bracing, and the appearance of the block. As a submittal a real guitar was taken and the geometrical pararmeters are precisesly modeled in the computer. These solutions are found by using the finite-element method, which allows calculation of the different eigenfrequencies and mode shapes of the guitar body.
Modeling of steeldrum sounds using finite element and finite difference methods
Authors: Steppat Michael
Published: October 2013

The Caribbean steeldrum, which was developed over 60 years ago in Trinidad, is one of the most novel music instruments. It is made of leftover oil drums. On the bottom of these drums, dents can be formed with a specialized technique, to get playing areas with a definite pitch. The tonal range of a whole orchestra can be reached with different models, covering a tonal range from bass to soprano. Despite the usage of the same material and even if they are made by the same tuner, the instrument can sound very different. Good instruments can be played in various striking strengths, without producing interfering noise. Instruments of weaker quality tend to produce interfering noice, even at small striking strengths. The sound of the instrument can be simulated with the finite difference method and finite element method . With the finite element method, a model of the vibration system can be formed by small rectangular plate elements. To simulate the sound of a note, a transient response analysis can be calculated. The simulation takes various production techniques into account, e.g., different shapes of the dent.
Quantitative nanomechanical measurements and imaging with atomic force microscopy methods
Authors: Hurley D. C. , Kopycinska-Mueller M. , Geiss R. H. , Langlois E. D. , Kos A. B.
Published: October 2013

We describe our work to evaluate the nanomechanical properties of surfaces, thin films, and nanostructures using the atomic force microscope (AFM). Our approach is based on atomic force acoustic microscopy (AFAM) and involves the resonant vibrations of an AFM cantilever in contact with a sample. We first describe the basic principles of AFAM, in which local elastic-property values are determined from the contact-resonance frequencies using models for the cantilever dynamics and for the tip-sample contact mechanics. Quantitative results for a variety of thin supported films ranging in stiffness from 50 to 250 GPa and as thin as 50 nm are given to illustrate our methods. Studies related to measurement accuracy involving the effects of film thickness and tip shape are also presented. Finally, we discuss new frequency-tracking electronics for rapid (typically 20 min per image), quantitative imaging of nanoscale elastic properties. We describe how such methods not only provide modulus mapping capabilities, but also have enabled us to detect variations in adhesion between a thin film and substrate.
Nanoscale acoustical imaging—deep or superficial?
Authors: Kulik Andrzej J. , Gremaud Gerard , Forro Laszlo , Szoszkiewicz Robert , Burnham Nancy A.
Published: October 2013

Several ideas of near-field detection of ultrasonic vibrations of the sample surface using atomic force microscopy (AFM) have been developed. Two major techniques are used: contact and nonlinear detection (intermittent contact). Most of the experiments were performed using low-MHz frequencies, meaning that wave propagation can be neglected in thin and small samples. In this talk we will analyze and present data obtained using two techniques: (a) contact measurements, where surface vibrations are sensed by the AFM tip, mapping local stiffness of the sample [Burnham et al., J. Vac. Sci. Technol. B 14, 794–796 (1996)], and (b) ‘‘mechanical diode’’ measurements, where high-amplitude surface vibrations are detected through nonlinearity of tip-sample interactions. This method gave access to local adhesion hysteresis [Szoszkiewicz et al., Appl. Surf. Sci. 210, 54–60 (2003); J. Appl. Phys. 99, 014310 (2006)].
Comparison of atomic force acoustic microscopy and dynamic nanoindentation methods for compliant polymer systems
Authors: Stagemeyer Matthew , Turner Joseph A. , VanLandingham Mark R.
Published: October 2013

Nanomechanical characterization of soft materials such as polymers and polymer composites represents a unique and challenging research topic of current interest. In this presentation, two characterization methods are compared directly using a set of model PDMS polymer systems. Experiments were conducted using both nanoindentation and atomic force acoustic microscopy (AFAM) to determine the dynamic mechanical properties. The experiments were conducted to determine reduced elastic modulus E* via AFAM measurement and storage modulus E via nanoindentation. The AFAM analysis was done using both a Hertzian contact model and a flat punch model. While the two methods showed marginal agreement, the resulting AFAM moduli were dependent on the model used in the analysis. Further investigation is needed to improve the accuracy of these measurements. In addition, further modeling is needed to improve the understanding of the tip-sample interaction in such systems. The results are anticipated to lead to the development of improved characterization methods for compliant materials. [Work supported by ARL.]
Testing the role of harmonic number in the contribution of a nonsimultaneous mistuned harmonic to residue pitch
Authors: Gockel Hedwig E. , Carlyon Robert P. , Plack Christopher J.
Published: October 2013

Ciocca and Darwin [J. Acoust. Soc. Am. 105, 2421–2430 (1999)] reported a surprising finding: Mistuning the fourth harmonic produced the same residue pitch shift when presented after the remainder of the complex as when it was simultaneous. They concluded that partials are integrated over a period of 170–250 ms for the calculation of pitch. Gockel et al. [J. Acoust. Soc. Am. 118, 3783–3793 (2005)] failed to replicate this result, but mistuned the third harmonic. Here, subjects adjusted a matching sound (harmonic complex) so that its pitch equaled that of a subsequent 90-ms complex tone (12 harmonics of a 155-Hz F0) containing a mistuned (±3%) third or fourth harmonic. Pitch shifts were significantly larger when: (i) the mistuned harmonic was presented simultaneously with, rather than after, the remainder of the target complex; (ii) the fourth rather than the third harmonic was mistuned; (iii) the nominally mistuned harmonic was present in, rather than absent from, the matching sound. The results again contrast with Ciocca and Darwin’s findings and contradict the idea of obligatory integration over a long time period for the formation of residue pitch. [Work supported by EPSRC Grant EP/D501571/1.]
Onset transient significance in listener identification of pipe organ stops
Authors: Disley Alastair C. , Howard David M.
Published: October 2013

Pipe organs typically contain many ranks of pipes, but it is uncertain whether listeners can discern the often subtle differences between different ranks. The importance of onset transients in timbral identification is well established, but in many pipe organ listening situations, the transient is obscured. This paper explores the significance of organ pipe onset transients in an experiment based on Berger’s work on orchestral timbre (K. W. Berger, J. Acoust. Soc. Am. 36, part II, 1888 (1963)] Listeners familiar with the pipe organ attempted to identify recordings of single organ pipes, representing commonly found types of organ stop. Each pipe was presented on different occasions with its own transient and with artificial transients created by amplitude ramps. The results demonstrate that when onset transients are present, expert listeners are adept at identifying the general tonal nature of a stop, but are less adept at precise identification. Replacement of transients with amplitude ramps resulted in a decrease in both precise and general correct identification. The subjective mapping demonstrated between pipe names and their spectral features is explored. Onset transients are shown to be important in listener identification of pipe organ stops.
Investigating auditory induction without complete continuity
Authors: Aronoff Justin
Published: October 2013

Auditory induction, the process of restoring missing auditory information, plays a crucial role in perception. A number of researchers have examined the characteristics of this phenomenon when there is a signal anchoring both sides of the induced sound (i.e., complete anchoring). However, the characteristics of partially anchored induced sounds (i.e., anchoring on only one side of the induced sound) are largely unknown, although prior research suggests that such partially anchored induction can occur [Wrightson and Warren, J. Acoust. Soc. Am. 69, S105–S106 (1981)]. To examine the characteristics of this latter type of induced sound, synthetic stop-initial syllables were used in a forced-choice task, allowing easy assessment of the type and amount of induced information. The first 25 ms of each transition was removed, and noise (used to elicit the induced sound) was added to the truncated transition in small segments, replacing the removed transition. Accuracy increased with increasing amounts of noise, indicating that induction was occurring with partial anchoring. However, this induction was strongly limited, extending only 15 ms into the noise. This suggests that complete anchoring plays an important role in extending the induced sound, although it is not necessary for its creation.
Decay curvature due to ‘‘losses’’ into a waveguide from a reverberant body
Authors: Weaver Richard
Published: October 2013

We study the dissipation of diffuse ultrasonic energy in a reverberant body coupled to an effectively infinite elastic waveguide. A simple model predicts a distribution of complex eigenfrequencies and a corresponding nonexponential (‘‘curved’’) dissipation. This behavior was predicted in its broad outlines by Manfred Schoeder and is largely confirmed by measurements. For the case of fully open channels, however, measurements deviate from the simple model to a statistically significant degree. A random matrix supersymmetric calculation is found to accurately model the observed behaviors at all coupling strengths. We discuss implications for modeling losses in large complex systems and, in particular, for modeling decay curvature.
Recording and environmental effects in sociolinguistic interviews: Implications for sociophonetic analysis
Authors: Kendall Tyler
Published: October 2013

Sociophonetians are often interested in examining speech that has been recorded in acoustically diverse conditions. Sociolinguistic methodology is centrally concerned with combating the observer’s paradox, finding ways to minimize informant’s awareness that they are under investigation, and often the requirements needed to ensure high-quality recordings conflict with this theoretical focus. While sociophoneticians are aware of some potential problems when comparing different speakers, with only rare exceptions have they examined the potential problems on both inter- and intraspeaker analyses due to recording and environmental effects. Meanwhile, other fields (especially computer speech recognition) have investigated the acoustic effects of environmental noise and recording equipment and have demonstrated that these factors impact the resulting speech signals in ways that are possibly significant for sociophonetics. This study emulates a number of traditional sociolinguistic interview recording techniques by taking an array of recordings for single interviews. Each interview is simultaneously recorded with a wired lavalier microphone connected to an audiocassette recorder, a unidirectional vocal microphone placed 2 ft from the speaker connected to an audiocassette recorder, and a wireless lavalier to a digital video camera. The results of phonetic analyses of these recordings, along with the implications for sociophonetic analysis, are explored.
Towards a probabilistic system for estimation of acoustic landmarks for speech recognition
Authors: Park Chiyoun , Slifka Janet
Published: October 2013

Algorithms for consonant landmark detection, such as Liu [S. Liu, J. Acoust. Soc. Am. 100, 3417–3430 (1996)], extract cues to specific types of abruptnesses in the acoustics. The abruptnesses indicate occurences of closure and release for obstruent and sonorant consonants, and burst release for stop consonants. In Liu’s algorithm, fixed thresholds are used to filter out abruptnesses that are unlikely to be true landmarks. The resulting set of landmarks does not retain any information regarding these filtered-out instances. However, such information may be useful later in the lexical access process, especially given the range of contextual variation in the speech signal. In this work, the landmark detection process is reformulated as a probabilistic system. First, thresholds are lowered to include more candidates, and then a probability value is calculated for each candidate. An N-best search is used to pick the most likely sequences of obstruent landmarks based on the calculated probabilities. Experiments with 80 sentences from the TIMIT database detect corresponding landmarks within 40-ms windows of 96% of hand-labeled obstruent landmarks, 98% of burst-release landmarks, and 76% of sonorant landmarks. Applying 5-best search results in 9% deletion and 4% insertion rate. [Work supported by NIH DC02978.]
Evaluation of token-based acoustic measures for classification of irregular phonation in normal speech
Authors: Slifka Janet , Surana Kushan
Published: October 2013

Quantification of the acoustic characteristics of irregular phonation provides a foundation for automatic detection of regions of irregular phonation in continuous speech. Recent results for automatic classification of regions of phonation as either regular or irregular demonstrate classification rates greater than 90% (false positive <10%) [K. Surana, M.Eng. thesis, MIT, Cambridge, MA 2006]. Similar acoustic cues may be useful in separating subtypes of irregular phonation. Two types of irregular phonation are examined: (1) regions characterized by reduced airflow, assumed to correspond to tightly adducted vocal folds with brief regions of separation, and (2) regions characterized by increased airflow, assumed to correspond to a spread or spreading vocal-fold configuration [J. Slifka, J.Voice (in press)]. Reduced-airflow tokens are extracted, using airflow, audio, and electroglottography signals, from utterance-medial locations, and increased-airflow tokens are all utterance final (20 tokens/speaker, 4 speakers). Surana’s cue set was evaluated for the ability to separate these subtypes of irregular phonation. Preliminary results indicate that an energy difference measure (between tokens smoothed at 6 vs 16 ms) and normalized rms amplitude yield statistically separable populations. Limitations on the use of these cues are discussed including intra- and interspeaker variation and the effect of token duration. [Work supported by NIH DC02978.]
Sentence comprehension when formant transitions are present or absent by normal-hearing and hearing-impaired listeners
Authors: Lee Jae Hee , Kewley-Port Diane
Published: October 2013

Burkle et al. [‘‘Contribution of consonant versus vowel information to sentence intelligibility by normal and hearing-impaired listeners,’’ J. Acoust. Soc. Am. 115, 2601 (2004)] reported that young normal-hearing (YNH) and elderly hearing-impaired (EHI) listeners recognized sentences better with only vowels compared to only consonants in a noise replacement paradigm. Using the same paradigm, this experiment examines whether the 2:1 benefit was due to the type of information presented in whole segments or to the proportion of total sentence duration. Forty-two sentences were processed to present only steady-state or dynamic transition information, rather than whole segmental information. YNH and EHI listened to sentences with 50% and 70% proportion of total sentence duration, and the number of words that listeners correctly repeated in sentences was scored. There was no effect of processing conditions. For sentences with 50% and 70% proportions, YNH recognized 60% and 84% of the words across conditions, while EHI recognized only 16% and 45%. The benefit ratio for the 70% proportion compared to 50% was 0.4 for YNH and 3.7 for EHI. YNH improved linearly with increases in proportional duration regardless of the type of information presented. EHI improved with proportional duration, but less systematically, and were more affected by the type of information. [Supported by NIHDCD-02229.]
Applications of Markov chain Monte Carlo methods in ocean acoustics
Authors: Battle David
Published: October 2013

Markov chain Monte Carlo (MCMC) methods have recently been applied to ocean-acoustic parameter estimation problems, as well as to model selection, wherein different parametrizations can be compared to assess which model most efficiently describes acoustic field measurements at a given signal-to-noise ratio. This talk will deal with some ocean-acoustic applications of Monte Carlo parameter estimation, including approaches to calculating Bayesian evidence integrals for model selection. The talk will conclude with a discussion of known defects in algorithms currently available and some possible future directions for algorithm development.
Mean, variance, and temporal coherence of the 3D field forward propagated through random internal waves in deep-ocean waveguides
Authors: Chen Tianrun , Ratilal Purnima , Makris Nicholas
Published: October 2013

An analytical expression for the temporal coherence of an acoustic signal propagated through a 3D random internal-wave field in a deep-ocean waveguide is derived. The modeled coherence time scale of the acoustic fluctuations at 3000-km range is on the order of 10 min and matches the ATOC experimental measurement. It is found that the 3D scattering effects on the forward field become pronounced when the Fresnel width exceeds the cross-range coherence length of the internal-wave field. The depth-integrated intensity losses due to internal waves first increase then decrease as frequency decreases from 75 to 10 Hz. These results are derived by applying a general modal solution for the statistical moments of an acoustic field propagating through 3D random inhomogeneities [Ratilal and Makris, ‘‘Mean and covariance of the forward field propagated through a stratified ocean waveguide with three-dimensional random inhomogeneities,’’ J. Acoust. Soc. Am. 118, 3532–3559 (2005)] to the acoustic propagation through a random internal-wave field. The mean and variance of the forward field are expressed in terms of the stochastic moments of the inhomogeneous medium’s scatter function density. This is derived by applying the Rayleigh-Born approximation to Green’s theorem in terms of the medium’s compressibility and density fluctuations, which are related to the displacement of internal waves. The statistical properties of the displacement of internal waves are formulated with the Garret-Munk spectrum.
The vertical structure of shadow-zone arrivals at long range in the ocean
Authors: Van Uffelen Lora J. , Worcester Peter F. , Dzieciuch Matthew A. , Rudnick Daniel L. , Cornuelle Bruce D. , Munk Walter H.
Published: October 2013

Multimegameter-range acoustic data obtained by bottom-mounted SOSUS receivers show significant acoustic energy penetrating several hundred meters into the geometric shadow zones below cusps in the predicted acoustic time fronts, much further than can be accounted for by diffraction [Dushaw et al., IEEE J. Oceanic Eng. 24, 202–214 (1999)]. Acoustic data from two vertical line array receivers deployed in close proximity in the North Pacific Ocean, together virtually spanning the water column, show similar shadow-zone arrivals for transmissions from broadband 250-Hz sources moored at the sound-channel axis (750 m) and at surface conjugate depth (3000 m) at ranges of 500 and 1000 km. The vertical structure of the receptions will be compared to parabolic equation propagation simulations for sound-speed fields constructed from high-resolution underway conductivity-temperature-depth (UCTD) data in the upper 400 m, widely spaced deep CTD casts, and climatological data. Predictions will be made (i) for the observed field; (ii) for a smoothed field, and (iii) for fields that include sound-speed fines structure due to density variations (internal waves) or due to density-compensated sound-speed variations (spice).
Regions where transient signals are influenced between a source and receiver
Authors: Spiesberger John
Published: October 2013

At infinite frequency, a medium only influences the waveform of a received signal emitted from a source along one or more infinitesimally thin rays. For transient signals at finite frequencies, an exact method is developed to compute the regions in a medium that significantly influence the received signal for any specified window of signal travel time. Results are (1) in homogeneous media, a significant portion of the signal originates from waves that traverse paths that are approximately integer and half-integer numbers of cycles greater than the straight path between source and receiver. Called ‘‘constructive and destructive paths of influence,’’ they do not obey Fermat’s principle of path stationarity. (2) For reflection from a flat interface in a homogeneous medium, the received signal is significantly influenced by constructive and destructive paths of influence whose angles of incidence and reflection differ. (3) Near 100 Hz in an oceanic waveguide, the region of influence markedly departs from a ray. Near upper turning points, the influential region is flat for O(10) km instead of O(1) km for a ray. (4) The first Fresnel zone is an inappropriate scale to characterize the region of influence for transient signals near a steep ray in inhomogeneous media.
Effect of shelf break front on acoustic propagation
Authors: Miller James H. , Potty Gopu R. , Moore Kristy A. , Lynch James F.
Published: October 2013

The effect of a shelf break front on acoustic propagation is discussed in the context of the Shallow Water Experiment (SW-06) in the New Jersey Shelf. The primary effect is a horizontal analog to the classical horizontal Lloyd’s mirror effect, produced by the fact that fronts can totally internally reflect sound incident upon them at low grazing angles. The direct and reflected modal rays add up to produce an interference pattern in range. It has been shown [Lynch et al., ‘‘Consideration of finescale oceanography and 3D acoustics effects for the ESME sound exposure models,’’ IEEE JOE (in press)] based on simple calculations that this frontal effect has the potential to increase the maximum insonification level up to 6 dB. Noise measurements analyzed using the SWARM -95 data also provide some evidence to this effect. The present study explores this effect in more detail using a horizontal ray-vertical mode approach. Calculations were made using environmental parameters corresponding to the New Jersey Shelf area, where field measurements will be made in 2006 to explore this effect. [Work supported by Office of Naval Research.]
Shallow-water waveguide characterization using an autonomous underwater vehicle-towed hydrophone array
Authors: Holmes Jason D. , Carey William M. , Lynch James F.
Published: October 2013

Sound transmission results are reported for frequencies of 220, 415, 635, 823, 1031, and 1228 Hz in an iso-velocity waveguide 13 m deep with known bottom properties. The experiments were conducted in Nantucket Sound in proximity to the Lynch-Frisk (1982) experiment in an area surveyed prior to the experiments. A fixed source and an autonomous underwater vehicle six-element towed hydrophone array were used. The experimental track consisted of two 2–4-km straight legs with measurement of the bathymetry and currents performed by the vehicle. Transmission results show stable modal-multipath interference effects with predictable phase rate variations. Coherent processing using vehicle estimates of ground speed and position yields results close to theoretical expectations and indicates a constant depth stable tow was realized. Horizontal wave-number spectra using coherent synthetic aperture Hankel transforms are presented and shown to be calculable and comparable to the previous work. The demonstration of this measurement capability provides for cost effective measurements of the sound field at sea.
John Kopec and the papers of Wallace C. Sabine
Authors: Beranek Leo L.
Published: October 2013

In April 1975, the Illinois Institute of Technology called the author saying that some notebooks had been found that appeared to be those of Wallace Clement Sabine. It was thought previous to this find that Sabine had destroyed all of his notebooks and papers because none was found when Professor Theodore Lyman was collecting Sabine’s papers for publication. Those notebooks were studied, a paper was published [J. Acoust. Soc. Am. 61, 355–365 (1977)], and they were deposited in the Harvard University Archives. Imagine the surprise when John Kopec called in early 1979, saying that at another location at the Riverbank Acoustical Laboratory, a pile of folders that contained some of Sabine’s consulting experiences had been discovered. John said that he had copied Sabine’s faded pages into typescript, and he invited the author to join with him in studying them and perhaps publishing a paper jointly with him. Discussed here is our work together and our publication of the results [J. Acoust. Soc. Am. 69, 367–382 (1981)]. Through this effort readers can judge Sabine’s breadth of activity and his depth of understanding in the field of applied acoustics.
Comparative analyses of canine hearing using event-related potentials
Authors: Scheifele Peter M. , Darre Michael , Pinto Michelle G. , Musiek Frank E. , Preece John
Published: October 2013

The hearing of three dogs was tested using auditory brainstem response (ABR) and distortion product oto-acoustic emissions (DPOAE) tests. The three subject dogs included one with known normal hearing, one congenitally deaf dog, and one dog with presbycusis. ABRs were run using a 100-s click stimulus at a repetition rate of 19.7 Hz at 90, 60, and 40 dB nHL. Based on the combined analysis of ABR and DPOAE, differences in canine hearing of dogs with presbycusis and congenital (Waardenburg syndrome) are evident. These results continue to be compared with those of other dogs of known otology and audiology in an effort to develop canine norms for ABR and to readily detect these pathologies in companion animals to assist veterinarians in the diagnosis and treatment of hearing loss in dogs.
Speech privacy in design: A cost-privacy analysis
Authors: Lavallee Tim , Good Kenneth
Published: October 2013

With the development of new standards in the health care industry, design professionals will soon have additional construction criteria to ensure speech privacy in new facilities. There are currently sound transmission class (STC) ratings required for partitions in a healthcare setting outlined in the Guidelines for Design and Construction of Hospital and Healthcare Facilities. These currently implemented criteria have traditionally focused on patient personal privacy and not speech privacy. This effort will be a general analysis to determine the shortcomings of these standards with respect to speech privacy and a cost-privacy analysis for commonly used wall constructions. Wall constructions included in the analysis will be suitable for a healthcare setting. Commonly referenced published, modeled, and measured transmission loss across partitions will be shown. The privacy indices will be evaluated for each configuration. The talk will highlight that, in most cases, no extraordinary measures will be needed to ensure reasonable safeguards have been implemented.
Universal properties of the channel Q function: Applications to underwater acoustic communications
Authors: Yang T. C.
Published: October 2013

Channel Q function is, for a time-invariant channel, the sum of autocorrelation functions of the channel impulse response functions over multiple receivers [T. C. Yang, IEEE J. Oceanic Eng. 28, 229–245 (2003)]. It can be used to characterize the performance (output SNR) of acoustic communications using either passive-phase conjugation or decision feedback equalizer [T. C. Yang, IEEE J. Oceanic Eng. 29, 472–487 (2004)]. Channel Q function also determines the channel capacity for a single source and multiple receivers (SIMO). We analyze in this paper the properties of the channel Q function and show that it possesses universal and stable properties for underwater acoustic waveguides, irrespective of the channel sound-speed profiles, source and receiver range/depths. This property is examined with real data collected in various oceans with significant temporal variations in the propagation conditions and/or source-receiver range. Applications to underwater acoustic communications are discussed. [Work supported by the Office of Naval Research.]
Error performance of equalizers based on sparse and dynamic channel estimation
Authors: Li Weichang , Preisig James C.
Published: October 2013

For broadband communications in the very shallow water environment, it has been shown that both model-based dynamic channel estimation and sparse channel estimation are capable of reducing the signal prediction error by several dB [W. Li and J. C. Preisig, J. Acoust. Soc. Am. 118, 2014 (2005)]. Dynamic channel estimation is based on explicit modeling of the rapid channel variations; sparse channel estimation exploits the channel structure formed by the resolved multipath arrivals. In this paper, the error performance of the equalizer based on these channel estimators are analyzed, demonstrated through experimental results and compared with the performance of equalizers that do not explicitly model and exploit the channel dynamics and structure. [Work supported by ONR Ocean Acoustics.]
The nature of aspiration in stop consonants in English
Authors: Hanson Helen M. , Stevens Kenneth N.
Published: October 2013

The releases of aspirated stops in English are typically modeled as having three consecutive phases, which overlap somewhat in time: (1) transient, (2) frication, and (3) aspiration. Close examination reveals that the noise spectrum in the aspiration phase is sometimes dominated by one spectral prominence, rather than several prominences as expected with a glottal source. In this work, the possibility that frication noise generated during the third phase may sometimes dominate the aspiration noise is explored. The nature of the radiated sound during the production of both voiced and unvoiced stop consonants is examined for the three places of articulation in English and with several different following vowels. Data from eight subjects are observed. Results suggest that some subjects follow the classical model, but other subjects produce a mix of frication and aspiration during the third phase. There is considerable variability in these acoustic attributes, both within a speaker and across speakers. It is suggested that speakers can choose between using (1) an extended burst or (2) formant transitions to provide enhancing cues to place of articulation. The relation of these data to acoustic theories of sound production and to perceptual saliency is discussed. [Work supported by NIH Grant No. DC00045.]