bluuebunny/crossref_metadata_2025 huggingface dataset:
Phonetic study of North American languages history and results
Authors: Maddieson Ian
Published: October 2013

Serious phonetic study of North America languages started at the beginning of the 20th century. Within limits of available technology, aspects of speech articulation, aerodynamics and acoustics were investigated. One clear motivation was to understand how classes of sounds unfamiliar from study of better-known European and Asian languages were produced. Glottalized consonants and stops then referred to as ‘‘intermediate’’ (voiceless unaspirated) received particular attention. Nasal airflow, lip position in vowels, and tone and pitch accent were also investigated. Significant insights on relative timing were obtained, inter alia foreshadowing VOT measurement as a useful discriminator of laryngeal activity and revealing part of the mechanism by which ejective consonants are made. After the 1920’s, the idea of ‘‘psychologically real’’ phonemes which ignored phonetic differences became the ruling paradigm in American linguistics, contributing to a decline of interest in phonetic studies that basically lasted until around the 1980’s. When interest renewed, a new vision that phonetic patterns show regularities independent of phonemic structure guided research, and considerable attention was also paid to how indigenous American languages fit into overall phonetic typologies. Recent work is also often informed by concern for documentation of endangered languages and community interest in language revival.
Glottalization cues of Nuu-chah-nulth glottalized resonants
Authors: Caldecott Marion G.
Published: October 2013

Theories of positional neutralization (Steriade, 1997)] predict that pre-glottalized resonants should not occur word-initially because the cues to glottalization are not salient. Contrary to this, Nuu-chah-nulth, a Wakashan language, has pre-glottalized that do occur in word-initial position. This paper will show that a severely truncated resonant portion is the cue to glottalization in resonants in Nuu-chah-nulth. Previous research [Carlson et al., J. Jpn. Int. Prop. Assoc. 31, 275–279 (2001)] shows that Nuu-chah-nulth glottalized resonants consist of a stop closure that is phonetically identical to phonemic glottal stop followed by a (mostly) plain resonant. That study also found that glottalized resonants are twice as long in initial position as plain resonants. Following up on this, a pilot study [Caldecott and Kim, presented at the 1st annual Wakashan Linguistics Conference, 2004] indicated that the length of the resonant portion in glottalized resonants was in fact half that of a normal resonant. This paper expands on the previous study, incorporating new acoustic data on resonants in all word positions. Data are elicited from a fluent native speaker and measured using Praat. [Work supported by SSHRC.]
A near-real-time acoustic detection and reporting system for endangered species in critical habitats
Authors: Clark Christopher W. , Calupca Thomas , Gillespie Douglas , Von der Heydt Keith , Kemp John
Published: October 2013

Passive acoustics is an effective mechanism for detection and recognition of species-specific sounds and can be a more cost-effective approach than visual techniques for monitoring populations of rare or endangered species. A network of moored buoys has been strategically deployed in and around Cape Cod Bay to report detections of northern right whales in critical habitat. Each buoy continuously and automatically monitors for right whale contact calls and transmits detection and ambient noise data by cell or satellite phone to Cornell University on a regular basis. Each day, validated data are automatically unloaded into a Website database to provide on-line graphical and numerical data summaries. The array of three buoys deployed in the Bay will eventually be synchronized to allow localization and tracking of individual animals. [Work supported by funds from the NOAA Right Whale Grants Program and augmented by funds from the Commonwealth of Massachusetts Division of Marine Fisheries.]
Ship strike acoustics
Authors: Gerstein Edmund , Blue Joseph , Forsythe Steve
Published: October 2013

The confluence of Lloyds mirror effect together with acoustical shadowing and spherical spreading pose significant detection challenges for whales and manatees. Direct measurements of approaching vessels using horizontal and vertical hydrophone arrays demonstrate how the noise from vessels can become indistinguishable from ambient noise. Geometric scattering is also estimated for various hull dimensions as the acoustical shadows cast ahead of ships provide no warning to animals near the surface within the shadow zone. Animals at sufficient depths, or outside the shadow boundaries that hear approaching vessels, may seek refuge near the surface or directly in the path of vessels where it is relatively quiet. Speed reductions proposed to reduce collisions do not address the underlying acoustical challenges marine mammals face. Field measurements support predictions that noise intensity is proportional with vessel speed to the 5th power. In multiple ship environments the acoustical masking challenges are greatest and noise from slow vessels operating in marine mammal corridors can mask the sounds of distant faster moving vessels. A low intensity bow-mounted projection system has been designed to selectively fill-in acoustical shadows with modulated ship noise to mitigate masking and near surface effects, and neutralize the dangerous ambiguity posed by acoustical shadows.
An examination of temporal signal uncertainty for sequences of noise or random-frequency maskers
Authors: Leibold Lori , Neff Donna , Jesteadt Walt
Published: October 2013

The effect of temporal uncertainty was examined on detection of a 1000-Hz tone presented simultaneously with one of a sequence of five masker bursts, using a 2-AFC, adaptive procedure. The signal and each masker burst were 100-ms (10-ms rise/fall), with no temporal overlap between masker bursts. Each masker burst was 60 dB SPL. Across conditions, maskers were broadband-noise (300–3000 Hz) or random-frequency multi-tonal maskers with 1, 2, or 10 components. Components for the random-frequency maskers were drawn from 300 to 3000 Hz, excluding a 160-Hz band around the signal. Thresholds for conditions with no temporal uncertainty (signal presented with the first, third, or fifth masker burst on all trials) were compared to performance with maximal temporal uncertainty (signal position varied on every trial). There was no effect of temporal uncertainty for the noise masker. For random-frequency maskers, performance was uniformly poor for both fixed- and random-position signals, except for some release from masking for signals presented with the last masker burst. For three of four listeners, even 1-component maskers showed large amounts of masking in all conditions. These results suggest that the effects of temporal uncertainty are minimal for these stimuli. [Work supported by NIDCD.]
Stochastic resonance in Gaussian and uniform noise
Authors: Ries Dennis
Published: October 2013

The improvement in threshold of a 2.0 kHz tone in the presence of low levels of uniform and Gaussian noise is compared to tonal threshold measured in quiet. Uniform noise was created using a rectangular amplitude distribution. The noises were low-pass filtered at 12.0 kHz and were presented continuously throughout a run at spectrum levels ranging from 0 to −30 dB/Hz. Pure-tone signals were 400 ms in duration including 10 ms raised cosine onset and offset ramps. Thresholds were obtained using a 3-interval, forced-choice procedure with correct answer feedback in conjunction with a two down, one up adaptive tracking paradigm that targets 70.7% correct on the psychometric function. Subjects were instructed to select the interval that was different from the others. Preliminary results for the Gaussian noise conditions are similar to earlier results [Zeng et al., Brain Res. 869, 251–255 (2000)]. Initial results for the uniform noise indicate that it produced equivalent or slightly lower thresholds than those measured in the presence of Gaussian noise.
Tone-in-noise detection using narrowband reproducible maskers with restricted energy and envelope cues
Authors: Davidson Sean A. , Gilkey Robert H. , Carney Laurel H.
Published: October 2013

Both energy- and envelope-based models have been successfully used to predict narrowband tone-in-noise detection thresholds. To distinguish between these models, hit and false-alarm rates for 25 reproducible maskers were measured in the N0S0 and N0Sπ interaural configurations and 4 cue conditions: (1) normal energy and envelope cues, (2) restricted envelope cues, (3) restricted energy cues, or (4) restricted energy and envelope cues. Preliminary results show that hit and false-alarm rates were strongly correlated between the conditions with and without restricted energy cues, indicating that the reduction of energy cues did not substantially affect the detection process. However, hit and false-alarm rates were more weakly correlated between the conditions with and without restricted envelope cues, suggesting that the reduction of envelope cues did affect the detection process. Restricting envelope cues also had a larger (but still modest) effect on d′ under the N0Sπ configuration, but restricting energy cues had a larger effect for the N0S0 configuration. Overall, these results are more consistent with envelope-based models, but indicate that additional cues must play a role. [Work supported by NIDCD RO1-DC-001641 (LHC, SAD) and the Ohio Board of Regents (RHG).]
A new method of extracting the filter characteristics of the nasal cavity using homorganic nasal-stop sequences
Authors: Park Hansang
Published: October 2013

This study attempts to derive the filter characteristics of the nasal cavity of individual speakers. Since the only difference between a nasal and a homorganic voiced stop, such as [mb] and [nd], is whether the passage to the nasal cavity is open or not, the subtraction of the LPC spectrum of the voiced stop from that of the preceding nasal leads to the filter characteristics of the nasal cavity of an individual speaker regardless of place of articulation. The results showed that the spectral differences between samples of 20 ms taken from the steady states of the nasal and the following voiced stop were close to constant regardless of place of articulation, representing characteristic poles and zeroes, and that the spectral differences varied with speakers. This study is significant in that it provides a new method of extracting the filter characteristics of the nasal cavity, and that the spectral difference between a nasal and a homorganic voiced stop can be used as a parameter of the filter characteristics of the nasal cavity of individual speakers.
Acoustic eigenmodes and formant-cavity affiliations for the time-varying vocal tract
Authors: Ramsay Gordon , Rubin Philip , Best Catherine
Published: October 2013

Acoustic analyses of speech production are often based on assumptions about formant-cavity affiliations. Typically, these are derived from approximations based on coupled resonators, or from small-perturbation analyses for open vowel configurations. Few studies have accurately calculated formant-cavity affiliations for tightly-constricted vocal tract shapes, or for vocal tract shapes that change in time. In this paper, we show how to determine the acoustic eigenmodes of the vocal tract from a physical simulation, and apply this to examine time-varying formant-cavity affiliations during sequences of consonants and vowels. A state-space model of quasi-one-dimensional acoustic wave propagation in a time-varying elastic tube is derived, using the finite volume method. The eigenvalues and eigenvectors of the resulting implicit matrix recursion are shown to determine the formant frequencies and bandwidths, and the spatial distribution of potential and kinetic energy for each formant, at each point in time. Illustrations are given for examples of VCV sequences constructed using an articulatory model, including stops, fricatives, and approximants in different vocalic contexts. Formant-cavity affiliations, as defined by the localization of acoustic energy along the vocal tract, do not necessarily correspond to actual cavities. [Work supported by NIH.]
Bow bells—creating a sound community
Authors: Kiser Brenda , Lubman David
Published: October 2013

For centuries, the sound of ringing church bells has given communities a sense of identity. Church bells have long been used to announce significant events to the community, such as births and deaths, to warn of impending danger, to call the faithful to church and to announce the curfew. This paper focuses on one prominent example of a sound community-the church of St. Mary-le-Bow in the City of London, the location of the famous Bow bells. These bells have featured in Londons folklore and history since the 14th century and, to this day, identify those born within the sound of Bow bells as Cockney. This sound neighborhood was extended far beyond its natural borders when a recording of the bells was played by the BBCs World Service during World War II in broadcasts to occupied Europe. Sound examples are given. A short history of European church bells is presented. A cognitive scale is proposed, ranging from belonging to alienated, delineating psychological reactions of those within a sound neighborhood.
Autonomous remote humpback whale acoustic monitoring devices
Authors: Au Whitlow , Stimpert Alison , Lammers Marc , Johnson Niklas
Published: October 2013

Four acoustic monitoring devices controlled by a CF-1 Persistor Instrument Inc. microcontroller board were developed to monitor the chorusing sounds of humpback whales in their wintering grounds off the island of Maui. The units were programmed to turn on at the same time and sample chorusing sounds at a sampling rate of 3.33 kHz for 3 minutes every hour. The CF-1 was chosen because of its low power requirement of 40 ma while collecting data during the 3-min collection period, 3 ma while sleeping and 96 ma while storing the data onto a 2 Gbyte compact flash card. At this sampling rate, sampling period duration, and interval between sampling period, each unit has sufficient power to last 30 days when powered from a 12 Ahr lead acid battery. The 2 GB memory allows for 34 days of data collection. Four of these units were deployed along the west shore of Maui at locations separated by 15 to 20 miles. The amplitude of chorusing by singing humpback whales and the temporal characteristics at the different locations were obtained with these sensors during the 2005 humpback whale season.
Detection of FM signals in the presence of non-Gaussian noise
Authors: Urazghildiiev Ildar , Cortopassi Kathryn , Clark Christopher
Published: October 2013

In bioacoustics, the problem of detecting frequency-modulated signals in the presence of non-Gaussian noise is of great interest. Matched filters (MF) are often chosen over frequency-specific energy (FSE) detectors because of their improvement in both signal gain and target specificity. Under non-Gaussian conditions however, MF detectors do not ensure acceptable trade-off between false alarm and missed detection rate. To decrease false alarm rate, we propose a two-stage detection technique. First, a MF is applied, with threshold prescribed by the acceptable false alarm rate, to generate candidate detections. Second, a signal recognition (SR) algorithm is applied to the candidates. The SR algorithm estimates modulation parameters from the signal spectrogram, and a detection decision is made based on how well parameters match a criterion set for the signal of interest. We applied this technique to right whale contact calls recorded in Cape Cod Bay. Results demonstrate that the MF-SR technique decreases false alarm rate by 3–5 times, while not increasing missed detection rate from that of a MF only. These results were compared to those of a FSE detector followed by the same signal recognition and decision stage (FSE-SR), to determine if comparable performance could be achieved without the MF first stage.
Model to simulate the acoustical absorption of laminated fiberglass insulation
Authors: Arvelo Juan , Busch-Vishniac Ilene , West James , Ng Robert
Published: October 2013

While fiberglass insulation is known to be a very good acoustical absorber in the audible frequency range, it is not often used for this purpose in rooms because of its appearance and its delicate structural rigidity. Additionally, in some situations, notably medical facilities, the material is inappropriate because of its potential to trap and retain bacteria and dirt. In this work, we report on a study of laminate-coated fiberglass. Although the addition of a laminate coating degrades the acoustical absorption, previous experimental work demonstrated that the composite structure retains a high absorption coefficient. A model of the wall with the installed fiberglass/laminate composite was developed and a wavenumber integration approach was applied to this model to assess the impact of the laminate on the performance of the system. The estimated reflection and transmission losses are computed as functions of auditory frequency and incidence angles with and without the laminate layer to compare the distributions of acoustical energy. This work is performed under a Hafstad fellowship sabbatical appointment.
In situ measurement of absorption of acoustic material with a parametric source in air
Authors: Mellert Volker , Kruse Roland
Published: October 2013

Measurement of properties of acoustic material in situ is quite desirable in numerous applications. But pulse-echo methods often lack from spurious reflections in a closed-space environment. It is therefore necessary to irradiate the sample material with a highly focussed acoustic beam of defined width. The principle of parametric transducers, which is well known in underwater acoustics, can be used in air as well, if the sound pressure of the ultrasound carrier is high enough. This was recently demonstrated by Hibral and Zakharia (Proc. of the Joint Congr. of CFA/DAGA 04, Strasbourg 2004, p. 541). The new measurement set-up is in principle best suited for in-situ measurements due to the narrow beam-width. But ultrasound intensity, efficiency of generation of audio sound etc. give rise to several limitations. Applications of in-door measurements, in particular at grazing-angle, are presented.
Cavitation detection during ultrasound-assisted thrombolysis in porcine blood clots
Authors: Datta Saurabh , McAdory Louis E. , Tan Jun , Holland Christy K.
Published: October 2013

Substantial enhancement of recombinant tissue plasminogen activator (rt-PA) mediated thrombolysis can be achieved with exposure of a thrombus to pulsed ultrasound. However, the mechanism of this interaction has not yet been elucidated. In this work cavitation is investigated as a possible mechanism for enhancement in 120-kHz pulsed ultrasound-assisted thrombolysis. Porcine blood clots were immersed in plasma as control and exposed to rt-PA, ultrasound (0.35 MPa, 80% duty cycle, 1667 Hz pulse repetition frequency), or a combination of rt-PA and ultrasound. A confocally aligned active and passive cavitation detection system was employed to detect subharmonic emissions from stable cavitation and broadband superharmonic emissions from inertial cavitation. After exposure, clot mass loss was determined, and clots were subjected to immunohistochemical analysis of fibrin degradation. Spatial investigation of cavitation thresholds inside the clot, on the clot surface, and in the fluid surrounding the clot showed the threshold to be lowest on the clot surface. Stable cavitation was detected in clots exposed to ultrasound alone and a combination of rt-PA and ultrasound. Curiously, inertial cavitation was detected only in samples containing rt-PA. The presence of both stable and inertial cavitation correlated with increased clot mass loss and a distinct pattern of fibrin degradation on histologic evaluation.
Ultrasonic backscatter in two-dimensional domains
Authors: Ghoshal Goutam , Turner Joseph A
Published: October 2013

The scattering of elastic waves in polycrystalline materials is relevant for ultrasonic materials characterization and nondestructive evaluation (NDE). Ultrasonic backscatter measurements are used widely to extract the microstructural parameters such as grain size and also to detect flaws in materials. Accurate interpretation of experimental data requires robust scattering models. Line transducers are often used for ultrasonic experiments such that an appropriate model for these two-dimensional problems is needed. Here, a theoretical expression for the temporal backscatter is derived for such domains under a single-scattering assumption. The result is given in terms of transducer and microstructural parameters. In addition, the problem is examined in terms of numerical simulations using Voronoi polycrystals that are discretized using finite elements in a plane-strain formulation. The material properties of the individual Voronoi cells are chosen according to appropriate material distributions. Such numerical models also allow scattering theories, including the one discussed here, to be examined for well-controlled microstructures. Example numerical results for materials with varying degrees of scattering that are of common interest are presented. The numerical results are compared with the theory developed with good agreement. These results are anticipated to impact ultrasonic NDE of polycrystalline media. [Work supported by US DOE.]
Telecommunication in a disordered environment with iterative time reversal
Authors: Montaldo Gabriel , Lerosey Geoffroy , Derode Arnaud , Tourin Arnaud , de Rosny Julien , Fink Mathias
Published: October 2013

Recent researches in the area of wave propagation in random media applied to telecommunications showed that, contrary to intuition, reverberation or scattering of waves in a disordered medium can actually help to increase the information transfer rate. The key element therein is the ability of a communication system to exploit independent channels of propagation. We present a method to transmit digital information through a highly scattering medium. It is based on iterations of a time-reversal process, and permits to focus short pulses, both spatially and temporally, from a base antenna to different users. This iterative technique is shown to be more efficient (lower inter-symbol interference and lower error rate) than classical time-reversal communication, while being computationally light and stable. Experiments are presented: digital information is conveyed from 15 transmitters to 15 receivers by ultrasonic waves propagating through a highly scattering slab. From a theoretical point of view, the iterative technique achieves the inverse filter of propagation in the subspace of non null singular values of the time reversal operator. We also investigate the influence of external additive noise, and show that the number of iterations can be optimized to give the lowest error rate.
Phase mapping and sound radiation from Caribbean steelpans
Authors: Morrison Andrew
Published: October 2013

The Caribbean steelpan is one of the most interesting acoustic musical instruments invented in the last century. Although simple in design, the acoustic properties of the steelpan are surprisingly complicated. Holographic interferometry was used to determine the resonances of a low tenor steelpan. Placement of a vibrating mirror in the optical path of the reference beam expands the capabilities of the holography system to include phase measurements. Phase maps of several low resonances of notes on a Caribbean steelpan will be shown. Sound intensity measurements were taken to explore the relationship between the resonances and the radiated sound field. The pan was placed in an anechoic chamber, and selected notes were excited electromagnetically with a swept sinusoid signal. A two-microphone probe was used to gather sound intensity measurements. Sound intensity maps of the first three harmonics will be shown for several notes.
Applying vibration and acoustical radiation from musical instruments in a recording studio setting
Authors: Harght Pamela J.
Published: October 2013

Radiation patterns affect the musical characteristics of any instrument. Applying the radiation characteristics of instruments to microphone technique will enable musicians, audio engineers and students to capture the most-desirable sound, and understand how to position microphones efficiently and appropriately. This paper will use the research done on several instruments’ acoustical characteristics and apply it to microphone techniques in a professional-level recording studio at Berklee College of Music. Audio examples will be used to demonstrate microphone placement according to the acoustical radiation of musical instruments. [Thank-you to K. Anthony Hoover for his support and encouragment with this paper.]
The (non) categorical perception of place assimilated coronal stops
Authors: Gow David W.
Published: October 2013

English coronal place assimilation generally produces gradient modification of stop place cues. Acoustic analyses are presented that show that labial assimilation of coronal stops often produces a distinctive pattern of formant movement, hereafter referred to as the coronal step. The coronal step is characterized by an initial pattern of F1, F2, and F3 movement consistent with coronal closure, followed by a second wave of movement producing formant values at offset that are intermediate between those associated with coronal and labial stops. The perceptual consequences of this pattern were examined in categorization and 4I2AFC discrimination tasks using a linear /t/-/p/ synthetic VC continuum, as well as a continuum displaying a coronal step but produced by manipulating the same acoustic parameters. The linear continuum produced data consistent with strong categorical perception, while the stepped continuum showed no evidence of categorical perception. These results are discussed in the context of a model of the perception of assimilated speech that relies on the simultaneous activation of competing phonetic categories by assimilated segments. [Work supported by the NIH.]
Effects of reduced orosensory feedback on spectral characteristics of medioalveolar /s/
Authors: Laaksonen Juha-Pertti , Ojala Stina , Aaltonen Olli , Niemi Matti , Happonen Risto-Pekka
Published: October 2013

Effects of reduced orosensory feedback on the production of fricative sounds were studied by measuring spectral characteristics of medioalveolar /s/. Five Finnish male speakers produced sibilant /s/ embedded in 8 different word contexts under normal condition and under reduced condition, in which the tactile information from the tongue was reduced by blocking the lingual nerve on the right side by local anesthesia. Parameters of Long Time Average (LTA) spectrum (i.e., center of gravity, standard deviation, skewness, and kurtosis) were measured by Praat software for every speaker. In comparison between the two conditions, center of gravity, standard deviation, skewness, and kurtosis changed for every speaker. However, the changes were variable and individual. The results of acoustic analysis show that reduced tactile sensation have effects on tongue function producing spectral alterations for sibilant /s/. The inter-individual variation between different talkers suggests that there are no general compensatory mechanisms of speech production, but the mechanisms are highly speaker-dependent.
BMSA, a new Bayesian model selection criterion for assessing audiovisual models of speech perception
Authors: Schwartz J. L.
Published: October 2013

Audiovisual speech perception has provided matter for many model comparison and assessment studies. Most involved ‘‘Root Mean Square Error’’ (RMSE), a criterion based on the differences between predicted and observed probabilities of response in auditory, visual and audiovisual categorization experiments. RMSE is related to the best fit of a model considering data. However, some models are known for their ability to adapt to almost any data set. This is always associated to a large fit instability: very small variations of the model parameters lead to dramatic modifications of the predicted data. A new criterion is derived from the Bayesian Theory of model selection. Considering that best fit estimation is not error-free, model comparison in this theory involves the total likelihood of the model knowing the data, integrating on the whole parameter space. This results in penalizing a too flexible model, for which local likelihood is high, but global likelihood is low. An approximation of this criterion, called BMSA, is presented. This criterion, easy to compute, results in combining fit and stability. An application of the BMSA criterion in an audiovisual speech perception experiment is proposed, enabling to show for the first time that the fusion process is subject-dependent.
Is speech lazy or just efficient? A control-theoretic analysis
Authors: Rodrigues Luis , Kroeker John
Published: October 2013

This paper introduces a control-theoretic model that allows us to address the energy dynamics of the vocal tract system. The model can be generated directly from articulatory data. The model allows computation of the energy in a state transfer, from an initial to a final articulator configuration. This method can help determine the degree of physical feasibility of various proposed articulatory trajectories. The basic assumption is that the set of articulators evolve through configurations that minimize the energy spent by the system to produce an utterance. Minimum control energy gives a measure of how hard it is to reach a target point for the different articulators. Simulation results are presented corresponding to the computation of the minimum energy from the MOCHA database. The linear model is shown to be adequate for short, well-labeled segments. The results show the intriguing fact that minimum control energy seems to have an oscillatory (swinging) nature for the production of speech. Physical features such as time constants and natural frequencies of the articulators are derived. A control-theoretic model of the dynamics of the mechanical articulators of speech production could be a fundamental tool to understand the mechanism of speech production.
Articulatory settings of French-English bilingual speakers
Authors: Wilson Ian
Published: October 2013

The idea of a language-specific articulatory setting (AS), an underlying posture of the articulators during speech, has existed for centuries [Laver, Historiogr. Ling. 5 (1978)], but until recently it had eluded direct measurement. In an analysis of x-ray movies of French and English monolingual speakers, Gick et al. [Phonetica (in press)] link AS to inter-speech posture, allowing measurement of AS without interference from segmental targets during speech, and they give quantitative evidence showing AS to be language-specific. In the present study, ultrasound and Optotrak are used to investigate whether bilingual English-French speakers have two ASs, and whether this varies depending on the mode (monolingual or bilingual) these speakers are in. Specifically, for inter-speech posture of the lips, lip aperture and protrusion are measured using Optotrak. For inter-speech posture of the tongue, tongue root retraction, tongue body and tongue tip height are measured using optically-corrected ultrasound. Segmental context is balanced across the two languages ensuring that the sets of sounds before and after an inter-speech posture are consistent across languages. By testing bilingual speakers, vocal tract morphology across languages is controlled for. Results have implications for L2 acquisition, specifically the teaching and acquisition of pronunciation.
Range-dependent 3D scattering and reverberation in the continental shelf environment from biology, geology and oceanography
Authors: Ratilal Purnima , Lee Sunwoong , Lai Yisan , Chen Tianrun , Symonds Deanelle , Donabed Ninos , Makris Nicholas
Published: October 2013

Several unified scattering and reverberation models were developed in support of the ONR Acoustic Clutter Program. They include a range-dependent model based on the parabolic equation that can be used to efficiently model scattering from a random spatial distribution of random targets that obey the sonar equation in the waveguide and a similar but range-independent waveguide model based on normal modes for scattering from extended objects. Both these models are bistatic and fully 3D, and the latter model also accounts for modal coupling between propagation and scattering caused by extended objects in the waveguide. These models are applied to examine both coherent and diffuse scattering measured after beamforming and match-filtering on an array from schools of fish, plankton, volume inhomogeneities in the sea bottom, roughness on the seafloor, extended seafloor and sub-bottom features such as river channels and reflective strata, and internal and surface waves. We provide a review of the dominant sources of clutter as well as background reverberation for long range active sonar based on comparison of model predictions with measured data from the Acoustic Clutter Experiments of 2001 and 2003.
Adjoint-based control of nonlocal boundary conditions for Claerbout’s wide-angle parabolic approximation
Authors: Meyer Matthias , Hermand Jean-Pierre
Published: October 2013

This paper applies the concept of optimal boundary control for solving inverse problems in shallow water acoustics. A continuous analytic adjoint model is derived for a wide-angle parabolic equation (WAPE) using a generalized nonlocal impedance condition at the water-bottom interface. While the potential of adjoint methodology has been demonstrated for ocean acoustic tomography, this approach combines the advantages of exact transparent boundary conditions for the WAPE with the concept of adjoint-based optimal control. In contrast to meta-heuristic approaches the inversion procedure itself is directly controlled by the waveguide physics and, in a numerical implementation based on conjugate gradient optimization, much fewer iterations are required for assessment of environments that are supported by the underlying subbottom model. Furthermore, since regularization is important to enhance performance of full-field acoustic inversion, special attention is devoted to applying penalization methods to the adjoint formalism. Regularization incorporates additional information about the desired solution to stabilize ill-posed problems and identify useful solutions, a feature that is of particular interest for inversion of field data sampled on a vertical array in the presence of measurement noise and modeling uncertainty. Results show that the acoustic fields and the bottom properties embedded in the control parameters are efficiently retrieved.
Energetically optimal regularization in nearfield acoustical holography
Authors: Zhao Xiang
Published: October 2013

Regularization techniques, such as singular value discarding or Tikhonov regularization, are commonly used to improve estimate of source field to be reconstructed from measured acoustic pressures at many points in nearfield acoustical holography. Theoretically, however, the regularized solution always underestimates the sound power of the real source. This paper presents an energetically optimal regularization method to solve this problem in nearfield acoustical holography by introducing a compensation factor in the generalized cross-validation function used to determine the optimal regularization parameter based on the Tikhonov regularization technique. Numerical examples show that the resulting regularization parameter will not only ensure a good fit of the predicted acoustic pressures to all measured data, but also ensure that the sound power of the equivalent source is always in agreement with the measured sound power, thus making this regularization method more ideal and much better than others in finding a compromise between the fidelity to input data and the fidelity to source field, and yielding a robust solution to the source field. [Work supported by NSF.]
The motion of harp strings
Authors: Chan Gary , Waltham Chris
Published: October 2013

The harp is an instrument with a set of plucked strings that excite the sound board directly, without the medium of a bridge. The strings are positioned at an acute angle to the plane of the sound board. The quality of the sound produced depends on the motion of the string and its interaction with the resonances of the sound board. The string and sound board motions of small and large harps have been studied using small, fast position sensors. The results are compared to those of a simple non-linear model based on the measured elastic properties of the string materials, and those of the sound board. The implications for the sound production are discussed.
Autonomous underwater vehicle networks as integrated acoustic observation systems
Authors: Schmidt Henrik
Published: October 2013

Autonomous Underwater Vehicles (AUV) are rapidly being transitioned into operational systems for national defense, offshore exploration, and ocean science. However, the use the robotic platforms as components of integrated acoustic sensing systems is still at an early stage. Thus, for example, with recent advances in underwater navigation and communication, and collaborative robotics, networks of AUVs may have significant potential as moving tomographic networks for optimally and adaptively providing in-situ environmental estimates. Such concepts are important to the development and operation of environmenatally adaptive, autonomous littoral surveillance systems by providing environmental inversion specifically emphasizing the parameters significant for the actual platform configuration. Also such multi-AUV concepts have significant potential for subbottom characterization in the deep ocean, of increased importance in the offshore industry. For such systems to be operationally feasible, the limited underwater communication bandwidth makes it necessary for such systems to involve significant on-board processing, in turn requiring the acoustic sensing to be fully integrated with an onboard modeling capability and the platform navigation and control. The development of such new nested, distributed processing concepts, autonomously integrating sensing, modeling and control, is a significant challenge to the acoustics community. [Work supported by ONR.]
Detection ranges for acoustic based manatee avoidance technology
Authors: Phillips Richard , Niezrecki Christopher , Beusse Diedrich O.
Published: October 2013

The West Indian manatee (Trichechus manatus latirostris) has become endangered partly because of watercraft collisions in Florida’s coastal waterways. Several boater warning systems, based upon manatee vocalizations, have been proposed to reduce the number of collisions. One aspect of the feasibility of an acoustically based system relies upon the distance at which a manatee vocalization is detectable. The magnitude of environmental noise and manatee vocalizations, as well as the acoustic spreading properties of the habitat will help to estimate the detection range of a vocalizing manatee. This study combines measured source levels of manatee vocalizations with the modeled acoustic properties of manatee habitats to develop a method for determining hydrophone spacing requirements for acoustically reliant manatee avoidance technologies. In quiet environments (background noise 70 dB) it was estimated that manatee vocalizations are detectable at approximately 250 m, with a 6 dB detection threshold. In louder environments (background noise 100 dB) the detection range drops to 2.5 m. Noise generated by boating traffic is also investigated. In a habitat with 90 dB of background noise, a passing boat with a maximum noise floor of 120 dB would be the limiting factor when it was within approximately 100 m of the hydrophone.
Phonetic labeling along a formant transition duration continuum in children with specific language impairment
Authors: Sussman Harvey M. , Burlingame Elizabeth , Gillam Ronald B. , Hay Jessica F.
Published: October 2013

Fifteen children diagnosed with specific language impairment (SLI) and fifteen typically developing (TD) children were tested for identification performance on two synthetic speech continuua varying in formant transition durations (FTDs). One continuum varied from [ba]-to-[wa] and the other varied from [da]-to-[ja]. Several dependent measures were derived based on d’from signal detection theory. These measures were used to assess category boundaries and to indirectly assess sensitivity to phonetic changes in labeling category tokens along each continuum. The SLI group showed less consistent identification performance along the [ba]-[wa] series relative to the TD group, as well as reduced sensitivity to phonetic changes along the continuum. On the [da]-[ja] continuum, the SLI group revealed less consistent identification performance on the short FTD end, but similar identification levels to the TD group at the long FTD end. The overall results support the view that children with SLI reveal a deficiency in the processing of speech sounds at the level of segmental identity.
Importance of local attenuation on the estimation of scatterer size from ultrasound backscattered waveforms
Authors: Bigelow Timothy A. , O’Brien William D.
Published: October 2013

Estimating the characteristic size of the tissue microstructure from a statistical analysis of the backscattered power spectrum could improve the diagnostic capability of medical ultrasound. Previously, size estimates were obtained for focused sources after compensating for source focusing, the frequency-dependent attenuation along the propagation path (total attenuation), and the frequency-dependent attenuation in the region of interest (local attenuation) given the attenuation values. In this study, the importance of the local attenuation on the scatterer size estimate was determined using computer simulations. The simulations used Gaussian impedance distributions with an effective radius of 25 μm randomly positioned in a homogeneous half-space (attenuation from 0.05 to 1 dB/cm-MHz) sonified by a spherically focused source (f/1 to f/4). The total attenuation and focusing were assumed known. The scatterer size was estimated assuming that the local attenuation was zero, the local attenuation was the mean value of the true attenuation over the frequency range used to obtain the estimates, and the local attenuation was 0.5 dB/cm-MHz. These three size estimates were then compared to estimates obtained using the true local attenuation value as well as estimates obtained when both focusing and local attenuation were not compensated.
In vivo breast vibro-acoustography
Authors: Fatemi Mostafa , Alizad Azra , Whaley Dana H. , Greenleaf James F.
Published: October 2013

Vibro-acoustography is based on audio-frequency harmonic vibrations induced in the object by the radiation force of focused ultrasound. The resulting object vibration produces a hydrophone detectable acoustic emission that is a function of regional dynamic properties of the object at the vibration frequency. The amplitude of the hydrophone signal is mapped into an image that represents the object’s vibro-acoustic response to the radiation force by scanning the focused ultrasound across the object. Contrast in Vibro-acoustography images represent several properties of the object, including the dynamic characteristics at the audio frequency and scattering and absorption properties at the ultrasound frequency. A Vibro-acoustography system has been combined with a stereo-tactic x-ray mammography system for in vivo breast imaging and has been tested on a number of volunteers. Resulting images show soft tissue structures and microcalcifications within breast with high contrast, high resolution, and no speckles. The results have been verified using x-ray mammograms of the breast. The encouraging results from in vitro and in vivo experiments suggest further development of vibro-acoustography may lead to a new clinical breast imaging modality. [Work supported in part by a grant from the Susan G. Komen Breast Cancer Foundation. Vibro-acoustography is patented by MF and JFG.]
Causality and acoustic group velocity in dispersive media
Authors: Mobley Joel
Published: October 2013

This talk examines two specific issues related to causality and the group velocity of acoustic pulses in dispersive media. First, the causal prediction of group velocity from attenuation with finite-bandwidth Kramers-Kronig (K-K) relations is discussed. Without extrapolating beyond the measurement bandwidth, the causal linkages of resonant-type data are established using expressions derived from the acoustic K-K relations to predict group velocity and slope of attenuation (frequency derivative of attenuation). These predictions provide a stricter test of causal consistency than the determination of the phase velocity and attenuation coefficient due to their shape-invariance with respect to subtraction constants. Secondly, conditions under which the group velocity is the velocity of the peak in the envelope of a acoustic pulse are described. The spatial and temporal signatures of acoustic pulses with arbitrarily large (e.g., superluminal) and negative group velocities are also demonstrated. These signatures are shown to be consistent with both simple and relativistic causality.
Genetic and Environmental Determinants of Human NK Cell Diversity Revealed by Mass Cytometry
Authors: Horowitz Amir , Strauss-Albee Dara M. , Leipold Michael , Kubo Jessica , Nemat-Gorgani Neda , Dogan Ozge C. , Dekker Cornelia L. , Mackey Sally , Maecker Holden , Swan Gary E. , Davis Mark M. , Norman Paul J. , Guethlein Lisbeth A. , Desai Manisha , Parham Peter , Blish Catherine A.
Published: October 2013

Both genetics and environment contribute to human NK cell diversity.
Targeting RNA Foci in iPSC-Derived Motor Neurons from ALS Patients with a
C9ORF72
Repeat Expansion
Authors: Sareen Dhruv , O’Rourke Jacqueline G. , Meera Pratap , Muhammad A. K. M. G. , Grant Sharday , Simpkinson Megan , Bell Shaughn , Carmona Sharon , Ornelas Loren , Sahabian Anais , Gendron Tania , Petrucelli Leonard , Baughn Michael , Ravits John , Harms Matthew B. , Rigo Frank , Bennett C. Frank , Otis Thomas S. , Svendsen Clive N. , Baloh Robert H.
Published: October 2013

Antisense oligonucleotides can correct disease-specific phenotypes in cultured motor neurons differentiated from iPSCs derived from ALS patients with a
C9ORF72
repeat expansion.
Adaptation of audiovisual contents and their delivery means
Authors: Diallo Mamadou Tourad , Moustafa Hassnaa , Afifi Hossam , Marechal Nicolas
Published: October 2013

Coupling content adaptation with context awareness is a promising approach for improving the user's experience.
Considering privacy issues in the context of Google glass
Authors: Hong Jason
Published: October 2013

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Jason Hong ponders why there has been so much negative press coverage of Google Glass with regard to privacy, considering the issue from two different perspectives.