bluuebunny/crossref_metadata_2025 huggingface dataset:
Frequency shifts in distortion product otoacoustic emission evoked by fast sweeping primaries in adults and newborns
Authors: AlMakadma Hammam A. , Prieve Beth A. , Dyab Walid M. , Long Glenis R. , Henin Simon
Published: May 2014

Distortion product otoacoustic emissions (DPOAEs) are a vector sum of two components, generator and reflection, which produce overall DPOAE levels with a pattern of minima and maxima across frequency referred to as fine structure. The pattern of maxima and minima shifts higher or lower in frequency dependent on sweep direction (Henin et al., 2011), consistent with cochlear scaling invariance. A break from scaling invariance occurs between 1 and 1.4 kHz in human adults. DPOAE phase at frequencies below the “break” are steeper in newborns than adults. We probed frequency shifts to up- and down-swept primaries of 1 octave/s in adults and newborns. Frequency shifts were examined for DPOAEs evoked by up-sweeps and down-sweeps using a covariate correlation function across the entire DPOAE frequency range, and above and below 2 kHz. Newborns had significantly greater frequency shifts in the reflection component below 2 kHz than adults. There was a significantly different fine structure frequency shift between the low- and high-frequency ranges in adults. In newborns, this difference in the frequency shifts for the low- and high- frequencies was significant for the reflection component. These preliminary findings suggest that frequency shifts can be used to assess potential maturational differences in cochlear mechanics.
Degraded temporal processing after traumatic brain injury
Authors: Hoover Eric , Souza Pamela E. , Gallun Frederick J.
Published: May 2014

Hearing complaints are common following traumatic brain injury (TBI) even in the absence of peripheral auditory impairment. Study goals were to explore the mechanisms which underlie this complaint. Adult listeners with a history of mild TBI or concussion were compared to young and age-matched controls. All listeners had normal or near-normal audiometric thresholds. Listeners with TBI reported difficulty understanding speech in noise. We hypothesized that hearing complaints after TBI are related to damage to neural pathways resulting in degraded temporal resolution. A battery of psychophysical tasks were used to test this hypothesis, specifically: monaural temporal fine structure, to evaluate temporal coding of unresolved harmonics; binaural temporal fine structure, to evaluate temporal coding of a low-frequency sinusoid; interaural coherence, to evaluate sensitivity to the similarity of a correlated broadband noise; and masking level difference, to evaluate the ability to take advantage of interaural phase for tone detection in noise. Results showed individual differences in temporal processing ability among listeners with a history of TBI. Test scores varied from normal to significantly impaired, despite normal audiometry. These results suggest that auditory temporal processing may be related to difficulty understanding speech in noise after TBI. [Work supported by NIH.]
Optically generated responses in the cochlear nerve
Authors: Matsui Suguru , Kobayasi Kota I. , Riquimaroux Hiroshi
Published: May 2014

Optical stimulation has been shown to substitute the electrical stimulation because the optical method can be more spatially selective, less invasive, and generate no electrical artifact, comparing to electrical stimulation. Previous study researched that pulsed near infrared laser irradiation to cochlear nerves in Mongolian Gerbil evoked the compound action potentials (CAP) in the cochlear nerves. Purpose of this study is to examine the differences between optically and acoustically induced CAP. Wavelength of the laser was 1.871 μm. The neural response was evaluated by using following parameters, pulse width (10–1000 μs), radiant exposure (0–2.017 mW), and repetition rate (1–1000 Hz). Click sounds used for comparison had similar parameters with the laser, click sound duration (10–1000 μs), sound pressure level (35–80 peak equivalent dB SPL), and repetition rate (1–1000 Hz). A silver wire electrode was set on the bony rim of the round window. Optically induced neural activity was confirmed at 1–1000 Hz repetition rate and was synchronized to stimulation cycles of 1–1000 Hz. Increasing radiant exposure induced larger CAP amplitude. Laser stimulation could reproduce CAP amplitude in the range of acoustically induced one. It is concluded that near infrared laser irradiation generates similar neural activities as click sound does.
Effect of basilar and tectorial membrane properties and gradients on cochlear response
Authors: Cormack John , Liu Yanju , Nam Jong-Hoon , Gracewski Sheryl
Published: May 2014

The cochlea is a spiral-shaped, fluid-filled organ in the inner ear that converts sound with high resolution over a large frequency range to neurological signals that can then be interpreted by the brain. The organ of Corti, supported below by the basilar membrane and attached above to the tectorial membrane, plays a major role in the amplification of small signals. In early fluid-structure interaction models of the cochlea, the mechanical properties of the organ of Corti were neglected and only the basilar membrane was considered, approximated by a series of springs. Recent experiments suggest that the mechanical properties and property gradients of the tectorial membrane may also be important for frequency response of the organ of Corti and that separate waves may propagate along the basilar and tectorial membranes. Therefore, a two-dimensional two-chamber finite difference model of the cochlea was developed to investigate the independent responses of the basilar and tectorial membranes. Responses are compared for models using one-, two-, or three-degree-of-freedom approximations for the organ of Corti, with parameters derived from a physiologically based finite element model. The effects of independent coupling of the fluid to the tectorial and basilar membranes and longitudinal coupling along the membranes are investigated.
Acoustic noise interferometry in the Straits of Florida at 100 m depth: A mode-based interpretation
Authors: Brown Michael G. , Williams Neil J. , Banker Geoffrey , Godin Oleg A. , Zabotin Nikolay A. , Zabotina Ludmilla
Published: May 2014

A field experiment designed to test the feasibility of noise interferometry was conducted in the Florida Straits in December 2012 in water of approximately 100 m depth. Ambient noise was recorded concurrently on three moored near-bottom instruments with horizontal separations of approximately 5 km, 10 km, and 15 km. Consistent with theoretical predictions, coherent sums (stacks) of many realizations of ambient noise at two measurement locations are shown to yield approximations to deterministic Green's functions that describe propagation between the two locations. Band-pass filtering of measured stacked cross-correlations reveal modal dispersion characteristics of the estimated Green's functions that are compared to mode-based simulations. [Work supported by NSF and ONR.]
Acoustic noise interferometry in the Straits of Florida at 600 m depth: Preliminary results
Authors: Brown Michael G. , Williams Neil J. , Zang Xiaoqin , Godin Oleg A. , Zabotin Nikolay A. , Zabotina Ludmilla
Published: May 2014

A field experiment designed to test the feasibility of noise interferometry was conducted in the Florida Straits in September/October 2013 in water of approximately 600 m depth. Ambient noise was recorded concurrently on three moored near-bottom instruments with horizontal separations of approximately 5 km, 10 km, and 15 km. Consistent with theoretical predictions, coherent sums (stacks) of many realizations of ambient noise at two measurement locations are shown to yield approximations to deterministic Green's functions that describe propagation between the two locations. Ray- and mode-based simulations of approximations to Green's functions are compared to measured stacked cross-correlations. [Work supported by NSF and ONR.]
Implementing physical constraints for noise-only mode shape estimation on real data
Authors: Rooney Ian M. , Buck John R. , Wage Kathleen E.
Published: May 2014

Many underwater acoustic tasks sample a narrowband pressure field with a vertical line array. In the absence of strong local sources, the noise sampled by an array includes both a spatially correlated and a spatially uncorrelated component. The acoustic waveguide's modes form a basis for the spatially correlated noise component generated by distant sources. This basis can be estimated from the eigenvectors of the noise sample covariance matrix. Propagation physics constrain the mode shapes to be real, but the eigenvectors are generally complex. These complex vectors require a phase rotation for each eigenvector prior to taking the real part. Previous work found that the eigenvector mode estimates' phases include spatially correlated noise. This noise correlation degrades the performance of spatial averaging and minimum variance estimates of the unknown phase rotation. The best estimate is the phase of the array element with the maximum magnitude for each mode, which is robust to the noise's spatial correlation. This research evaluates the previously developed phase rotation techniques using a real data set. The data was collected off the north coast of Elba Island by the SACLANT Centre in 1993. [This work was supported by ONR.]
Modeling the effects of air currents on acoustic measurements in large spaces
Authors: Griesinger David H.
Published: May 2014

Historically reverberation times were accurately measured with an explosive or an interrupted tone or noise. But in theory using convolution methods for acoustic measurement requires that an impulse response be precisely time stationary. Air in large spaces is never stationary, and the further a sound wave travels—as it must in a reverberant tail—the more it will be affected by moving air. Long stimuli and synchronous averaging increase the time over which the air must be still. We propose that air currents can be modeled through the fluctuations they create in the time base of the received stimulus. We find that noise-based convolution methods such as MLS are particularly sensitive to this problem, as they must use long stimuli to achieve an adequate signal-to-noise ratio (S/N). For these methods, when there is no net flow, the principle degradation is a rapid reduction of S/N at high frequencies. If there is a net flow, the high frequency reverberation time can also be significantly shortened. Logarithmic sine stimuli are shorter than MLS for an equivalent S/N, and are less sensitive to air currents. The relevance of these effects in actual spaces is under investigation.
Measuring sonic presence and the ability to sharply localize sound using existing lateral fraction impulse response data
Authors: Griesinger David H.
Published: May 2014

The ability to sharply localize sound sources creates a perception of presence that plays a large role in grabbing and holding attention, which is of major importance in learning and performance venues. The ability to localize accurately depends critically on how the audibility of the direct sound is reduced by reflected energy arriving in the first ~80 ms. Data analysis methods that quantify the ability to localize sound at a given seat from impulse response data are being developed—but binaural impulse response data is not common in acoustic data bases. Human hearing is not omnidirectional. It uses both ILD and ITD differences between the two ears to localize frontal sound sources with an acuity of about two degrees—far more accurately than current first-order microphones. Head shadowing also significantly lowers the strength of lateral reflections that arrive at each ear. This paper presents a method whereby existing data from omnidirectional and figure-of-eight microphones can be manipulated to emulate the ILD, ITD, and head shadowing of a binaural microphone. The method uses spherical harmonics and HRTF data to restore head shadowing and estimate the ITD and ILD of the direct sound and the first few reflections.
Behavioral and neuronal sensitivity concerning objective measures of auditory stream segregation
Authors: Klump Georg , Dollezal Lena-Vanessa , Itatani Naoya
Published: May 2014

To evaluate possible mechanisms of auditory stream segregation, it is desirable to directly compare perceptual stream segregation and its neurophysiological correlate. Objective measures of stream segregation, i.e., measures of perceptual sensitivity that differ between conditions in which one integrated stream or two segregated streams are perceived, lend themselves to the study of such phenomena. They can be applied both in studies involving human subjects and in animal studies on auditory streaming. On the one hand, we present results from a study on informational masking in Mongolian gerbils, in which better performance in an intensity discrimination task is observed if streams of target signals and distractors are processed in separate streams. On the other hand, we present results from a temporal pattern discrimination experiment in European starlings, in which better performance is achieved if the target signals and signals useful for temporal reference are processed within one stream rather than in separate streams. In both experiments we apply signal-detection theory both to the analysis of perception evaluated in behavioral experiments and to the analysis of neuronal response patterns on the midbrain and cortical level. The neuronal population response was observed to be well correlated with the behavioral sensitivity, which can shed light on the mechanisms underlying auditory stream segregation.
Concurrent inversion of bio and geoacoustic parameters from broadband transmission loss measurements in the Santa Barbara Channel
Authors: Diachok Orest , Wadsworth Glenn
Published: May 2014

This paper describes result of an interdisciplinary experiment, BAS II, which included coincident measurements of broadband (0.3–5 kHz) transmission loss (TL), depths and length distributions of fish, geoacoustic parameters, and continuous temperature profiles. The objective: demonstrate the accuracy of bioacoustic parameters of fish inverted from TL data. TL measurements were conducted between a fixed source and a fixed 16 element, receiving array that spanned most of the water column. Trawls revealed that the dominant species were sardines and anchovies. The TL data at night exhibited absorption lines at resonance frequencies associated with 15 and 8 cm long sardines, and 11, 9.5, and 5.5 cm long anchovies at 12 m, in good agreement with coincident trawl and echo sounder measurements. TL data during the day exhibited an absorption line associated with sardine schools. Concurrent inversion of bio and geoacoustic parameters of nighttime data was based on the Genetic Algorithm. The layer of fish was characterized by selectable depth, thickness and attenuation coefficient. Inverted values of biological parameters at 1.1 kHz, the resonance frequency of 11 cm sardines, were in accord with echo sounder and trawl data.
Spatiotemporal variability of clutter due to fish aggregations in the vicinity of Heceta Bank
Authors: Gauss Roger C. , Fialkowski Joseph M. , Love Richard H.
Published: May 2014

Acoustic interactions with fish can be a significant source of clutter to mid-frequency (MF; 1–10 kHz) active sonars. To develop robust schemes for reducing sonar false alarm rates, it is thus important to accurately characterize the spatiotemporal nature of MF echoes from fish. In the summer of 2012, long-range MF measurements of coherent backscattering from fish aggregations were made at several sites in the vicinity of Heceta Bank off the coast of Oregon. The dominant fish species included Pacific sardines that typically school near the surface and Pacific hake that typically are above the bottom in loose aggregations or layers, and so represent spatially different echo classes. Measured spatiotemporal fish echo statistics are discussed in terms of the observed in-situ distribution and behavior of these two species. NRL's moment-based Poisson-Rayleigh clutter model is used to physically relate the measured amplitude distributions to scatterer attributes (spatial density and dispersion). The temporal persistence of the clutter echoes is quantified via georeferenced echoes over multiple broadband transmissions. The results suggest that in this area, while fish may present a significant source of false alarms, their impact can be reduced by exploiting their short time-scale behavior. [Work supported by the Office of Naval Research.]
Accounting for the non-Rayleigh echo statistics of individual elongated scatterers in an aggregation
Authors: Lee Wu-Jung , Stanton Timothy K.
Published: May 2014

The statistics of echoes from active sonar systems, such as the shape of the probability density function (pdf) of echo magnitude, can be used to estimate the numerical density of scatterers in aggregations. This study investigates the importance of non-Rayleigh echo statistics of individual scatterers on the shape of the echo pdf of aggregations in which the echoes from individuals may overlap. The signals are broadband, and the geometry involves direct paths between the sonar and the scatterers without interference from the boundaries. Echo pdf models are generated by varying the number of scatterers randomly distributed in a half-space shell while accounting for the frequency-dependent system response and beampattern effects. Individual scatterers are modeled using elongated spheroidal shapes with varying distributions of lengths and angles of orientation. The non-Rayleigh echo statistics of individual scatterers were found to contribute significantly to the non-Rayleigh characteristics of the echo pdf of aggregations of those individuals. This model is applied to estimate the numerical density of fish in aggregations observed using broadband signals (30–70 kHz) in the ocean. The results show the importance of incorporating realistic parameters for modeling individual scatterers in echo statistical analyses.
Material properties of Pacific hake, Humboldt squid, and two species of myctophids in the California Current
Authors: Becker Kaylyn , Warren Joseph D.
Published: May 2014

We measured the material properties of Pacific hake (Merluccius productus), Humboldt squid (Dosidicus gigas), and two species of myctophids (Symbolophorus californiensis and Diaphus theta) collected from the California Current. Density contrast (g) was measured for pieces of hake and myctophid flesh, and the following Humboldt squid body parts: mantle, arms, tentacle, braincase, eyes, pen, and beak. Density contrast varied with fish species, as well as among squid body parts. Effects of animal length and environmental conditions on nekton density contrast were investigated. Sound speed contrast (h) was measured for hake and myctophid flesh, Humboldt squid mantle and braincase, and varied within and between nekton taxa. These material property measurements can be used to more accurately parameterize target strength models and increase the accuracy of nekton biomass from acoustic surveys.
Calibration of a broadband acoustic system in near-field
Authors: Eastland Grant , Chu Dezhang
Published: May 2014

This paper investigates the applicability of calibrating a broadband acoustic system in Near-field. The calibration was performed on a single transducer with a monostatic or backscattering configuration using a standard target, a 25-mm tungsten carbide sphere, in the near-field of both the transducer and the sphere. Theoretical model to quantify the near-field effect was developed in the paper. Theoretical simulations revealed that although the shape of the frequency responses of the received echoes at different distances varied significantly, the null positions were essentially invariant, a unique characteristic that was used to determine the compressional and shear wave speeds in the calibration sphere. The calibration curves obtained at different distances in the near-field by taking into account the near-field effect were consistent with each other. Since the transducer was located in the near-field, the signal-to-noise ratio was high, resulting in a much wider usable bandwidth, between 300 and 800 kHz, than the nominal bandwidth. The methods reported here could potentially be applied to the calibration of multibeam echosounder and sonar systems.
Ultrasonic phenotyping of breast cancer cells for molecular subtyping
Authors: Thompson Laurel A. , Stiles Janeese E. , Chappell J. Andrew , Calder Ashley N. , Carter Caitlin , Sugiyama Janice E. , Doyle Timothy E.
Published: May 2014

Breast cancer can be divided into molecular subtypes which are defined by their genetic and protein expression profiles. Current methods aimed at testing these biochemical signatures are effective classifiers but are not easily transferable to real-time clinical applications. The rapid, cost-effective determination of molecular subtype by other means would be a significant advancement in cancer detection and treatment. Our studies suggest that high-frequency ultrasound (10–100 MHz) may be sensitive to variations among breast cancer subtypes through their cytoskeletal structures, which have distinct biomechanical signatures. To further test this hypothesis, four breast cancer cell lines of different subtypes were cultured and ultrasonically tested. Direct pulse-echo measurements were collected from the cell layers using a 50-MHz transducer immersed in the growth media of the culture plates. Cell reflections in the waveforms were isolated and spectrally analyzed using computationally modeled spectra and principal component analysis (PCA). Cell phenotypes were profiled by using heat maps to display the relative distances between the PCA scores of the experimental and model spectra. The results indicate the phenotype and thus molecular subtype of cancer cells could potentially be determined by comparing their measured spectra to model spectra using a feature classification program such as PCA.
Clarinet playing frequency predictions: Comparison between analytic and numerical simulations
Authors: Coyle Whitney L. , Kergomard Jean , Guillemain Philippe
Published: May 2014

The input impedance measurement can provide the resonance frequencies of an instrument and is a standard method used by wind instrument makers in designing modifications. For a complete design, it is necessary to know the playing frequencies themselves, which depend on several control parameters, such as the blowing pressure and reed opening and the input impedance. Using the values of these parameters, we can determine the playing frequencies. This research will analytically deduce these frequencies from the different control parameters and from the input impedance curve. Four effects are known to influence the playing frequency and are examined separately: the flow rate due to the reed motion, the reed dynamics, the inharmonicity of the resonator, and the temperature gradient in the clarinet. The results for a particular clarinet are given and compared to numerically simulated playing frequencies. Experimental methods are also presented and discussed.
A cross correlation of stringed instruments
Authors: Pomian Katarzyna
Published: May 2014

Stringed instruments can be characterized by their individual body shapes, sizes, types of strings, and sounds. Studying the string resonance, body properties, and high speed photography of the strings, it is possible to describe the individual instruments in their specific functions. We gathered data for 13 different instruments and revealed the variances in their sound, based upon the unique characteristics of each instrument. Our focus was on the comprehensive analysis of the each instrument when correlating all the components of the data. We then aligned all the instruments together and investigated how the varying body shapes influence the sound that is produced by the specific instruments. Our analyses showed how these components work together to create the individually characterized sounds of the different instruments. [This paper is complementary to that of Gordon P. Ramsey.]
Detection of musical notes and chords using a holistic approach
Authors: Camacho Arturo
Published: May 2014

There are currently two main approaches for the automatic recognition of chords: (1) detecting chords from pitch class profiles, which gives information about chroma, but not height, and (2) detecting individual notes, either by peak picking from a score function or by detecting and then canceling individual notes. We propose a new method that combines both approaches: it detects chords in a holistic way, but at the same time, it gives information about the chroma and height of individual notes. The approach consists in computing scores for individual notes and chords, especially those in closed form (i.e., with small intervals between notes), and then picking the candidates with maximum score, either notes or chords. This approach, inspired in the way musicians perceive chords: as a whole and not as individual notes, avoids the iterative approach of detecting and canceling notes. The method works particularly well for notes within small intervals, which tend to be hard to detect in other approaches.
The unknown effects of amplitude envelope: A survey of Hearing Research
Authors: Gillard Jessica , Schutz Michael
Published: May 2014

In auditory research, the use of amplitude-steady tones with abrupt onsets and offsets is quite common. While these types of “flat” tones offer a great deal of control, they are not representative of the types of sounds we hear outside the laboratory. In everyday listening we are much more likely to encounter “percussive” (i.e., exponentially decaying) sounds, with offsets conveying detailed information such as the materials and force used to produce the sounds—information that is absent in abruptly ending flat tones. Given that differences in perception have been reported when using different amplitude envelopes (Grassi and Pavan, 2012; Neuhoff, 1998; Schutz, 2009), we became interested in determining the prevalence of flat and percussive tones in auditory research publications. Here, we surveyed the journal Hearing Research and classified the temporal structure of sounds used into five categories: flat, percussive, click train, other, and undefined. We found 42.5% of sounds were flat (approximately 13% were click trains, 4% other, and 40% undefined). This finding is consistent with our previous surveys of Music Perception and Attention, Perception, and Psychophysics, suggesting that flat tones dominate auditory research, and the perceptual effects of more naturalistic sounds are relatively unknown and ripe for future exploration.
Hearing better with interaural time differences and bilateral cochlear implants
Authors: Smith Zachary M. , Kan Alan , Jones Heath G. , Buhr-Lawler Melanie , Godar Shelly P. , Litovsky Ruth Y.
Published: May 2014

While bilateral cochlear implant (BiCI) recipients generally receive significant benefits from the addition of a second ear, evidence suggests that much of the benefit is attributed to monaural effects or to the availability of interaural level differences. The benefits are less than those in normal-hearing listeners, however, in part because the sound localization and speech unmasking that are measured may show greater benefits if interaural time difference (ITD) cues were also available. To date, there is a paucity of evidence that ITDs can be captured and saliently delivered by cochlear implant processors. In this study, we used a research processing strategy that explicitly codes ITD cues. We measured BiCI listeners' ITD sensitivity to broadband speech material and ITD-based unmasking in a multi-talker listening scenario by directly presenting sounds through the accessory inputs of their sound processors. Performance was compared to that with the commercial ACE processing strategy. Initial results show that some subjects with good ITD sensitivity can also take advantage of ITD to better understand a target talker in the presence of a masking talker at low target-to-masker ratios. This suggests that improving ITD perception in BiCIs may lead to better hearing outcomes in real-world listening situations.
Acoustic signature of underwater vehicles
Authors: Cuschieri Joe M.
Published: May 2014

Underwater vehicles are becoming more commonly used for a number of applications ranging from commercial to defense. While the acoustic signature of underwater vehicles is understood to be important, there are presently more pressing issues which are fundamental to the success of using underwater vehicles beyond the lab or controlled environment. Such issues incorporate power sources, navigation accuracy, reliable control, etc. However, while acoustic signature may not be in the forefront, need for low acoustic signature and low self-noise is important as the noise form the underwater vehicle can impact the operation of the acoustic sensors. In this paper, components that influence the radiated noise from underwater vehicles are identified and discussed, especially as these relate to their impact on the overall acoustic radiation. Approaches to estimate the underwater radiated noise based on other data when in water data is not available are discussed.
Domain of final lowering in spontaneous Japanese
Authors: Maekawa Kikuo
Published: May 2014

There are two opposing predictions about the domain of final lowering (FL) in Japanese intonation. One predicts that the domain is the last mora of utterance whereas the other predicts that the domain is much wider (with no clear specification of the domain). X-JToBI annotated part of the Corpus of Spontaneous Japanese (the CSJ-Core, 44 h speech spoken by 201 speakers) was analyzed to determine the domain of FL in Tokyo Japanese. Mean normalized F0 values of the four constituent tones of accented accentual phrases (AP) were compared across utterances differing both in the number of constituting APs (from 1 to 5) and the syntactic strength of sentence- or clause-boundaries (three levels). It turned out that all tones in the last AP of utterance were considerably lowered in all utterances regardless of utterance length. This suggests strongly that the domain of FL is the last AP in Japanese. It also turned out that FL occurred in much wider contexts than hitherto believed. FL was observed not only in typical sentence boundaries but also in various syntactic clauses, and there was correlation between the degree of FL and the strength of syntactic boundaries.
Individual differences in the perception of fundamental frequency scaling in American English speech
Authors: Veilleux Nanette , Barnes Jon , Brugos Alejna , Shattuck-Hufnagel Stefanie
Published: May 2014

Although most participants (N = 62) in an F0 scaling experiment judged open syllables (day) as higher in pitch than closed syllable tokens (dane, dave) with the same F0 contour, a subset did not. Results indicate that, in general, listeners perceptually discount F0 over coda regions when judging overall F0 level, and the degree of discount is related to the (lack of) sonority in the coda: day tokens are judged significantly higher than dane tokens which are judged significantly higher than dave tokens with the same F0 contour (dane-dave p < 0.001, dane-day p < 0.01). However, individual differences are observed: ten listeners showed no significant differences in the perception of F0 levels between the three types of tokens. On the other hand, a contrasting subset of ten subjects demonstrated highly significant differences (p< 0.001). The remaining 42 subjects behaved similarly to the entire subject pool with only slightly less significant differences between dane and day F0 level judgments (p < 0.05). Therefore, for about 16% of subjects, the F0 over the coda is not discounted in judging F0 level. These individual responses in F0 scaling perception mirror differences found in the Frequency Following Response (e.g., [1]) and could indicate individual differences in F0 processing.
Characteristics of speech production in a post-glossectomy speaker with a free flap: A case study
Authors: Zhou Xinhui , Woo Jonghye , Stone Maureen , Espy-Wilson Carol
Published: May 2014

It is unclear in glossectomy whether a flap will improve or impair speech, at least in the moderate sized (T2) tongue tumors. To gain some insights into this question, we studied the speech production of a post-glossectomy speaker, who had a T2 tumor surgically removed from the left side of his tongue and, closed with a radial forearm free flap (RFFF). Our acoustic analysis showed that this speaker had a significantly smaller vowel space and a significantly higher center of gravity in “sh”, but not in “s”, compared with the averages of normal controls or post-glossectomy speakers with primary closures. Based on cine and tagged magnetic resonance (MR) images, we analyzed the vocal tract shapes of two vowels and two fricatives and studied the tongue motion in transition of phonemes on this speaker and two controls. We will compare the vocal tract models between the flap patient and the controls. [This study was supported by NIH R01CA133015.]
Secondary gestures for consonants: An electromagnetic articulometer study of troughs
Authors: Nam Hosung , Shadle Christine H. , Tiede Mark , Saltzman Elliot , Whalen Douglas H.
Published: May 2014

Troughs, defined as a discontinuity in anticipatory coarticulation (Perkell 1968), have been shown to occur in the tongue body (TB) in /ipi/ and lips in /usu/. In V1CV1 contexts articulators retract from their vowel target during C when not active during C. We investigate the trough phenomenon by testing three hypotheses: (1) high intraoral air pressure during the consonant pushes TB down; (2) absence of vowel articulator activation during C in VCV causes TB to move to the neutral position; (3) the trough is a gesture in itself. Electromagnetic articulometer (EMA) data of the tongue, lips, and jaw were tracked for a trained phonetician producing non-words and real words, varying vowel context and the place, manner, and consonant length. For H1, /iCi/ productions with C={/p,f,m/} and three C durations were studied. For H2, /h/ and /ʔ/ in /iCi/ were examined. Troughs were found in all the labials but not in /h, ʔ/, disproving hypothesis 2; trough magnitude decreased in the order: /f/ > /p/ > /m/, disproving hypothesis 1. Trough magnitude increased with C duration, consistent with H3. Results from asymmetric vowel contexts also support H3, and will be discussed within the context of Articulatory Phonology. [Work supported by NIH.]
Accelerometric correlates of nasalized speech in children
Authors: Varghese Lenny A. , Mendoza Joseph O. , Braden Maia N. , Stepp Cara E.
Published: May 2014

Instrumentation-based scoring methods can be used to supplement auditory assessments, providing a more objective assessment of voice quality. One such metric that can be used to assess resonance disorders, the Horii Oral Nasal Coupling Index (HONC), has been shown to successfully separate nasal from nonnasal utterances, but has not been extensively studied in children. We have previously found that using low-pass filtered versions of the nasal accelerometer and microphone signal used in its computation can reduce variability due to vowel placement that is traditionally reported for these scores, and sought to determine whether this reduction in variability would extend to children's speech. We obtained nasal acceleration and speech signals from 26 children, aged 4–9, during the production of various consonant-vowel-consonant tokens and running speech with controlled vowel and consonant loading. HONC scores were compared using broadband and low-frequency portions of these signals. It was found that applying a low-frequency filter reduced the variability of the HONC scores due to vowel type relative to when broadband signals were used, and the scores could discriminate vowels produced in nasal and non-nasal contexts in children with high accuracy. These results demonstrate the potential of HONC scores as an aid in rehabilitating hypernasal speech.
Tense/lax discrimination in articulatory vowel space: Evidence from electromagnetic articulography
Authors: Mehta Sonya , Wang Jun , Katz William F.
Published: May 2014

A kinematic experiment investigated tongue movement for vowels in American English with the aim of developing spatial targets for use by subjects in real-time interactive learning/remediation environments. A 3D EMA system (AG501, Carstens Medezinelektronic, GmbH) was used to track the position of the tongue (tongue tip, TT, and tongue back, TB) and lips (upper lip, UL, and lower lip, LL) of adult subjects producing the vowels of American English (12 monophthongs and 3 diphthongs) in the consonant environment /bVb/. Here, we asked which of the tongue sensors yields the best spatial separation of the corner vowels /i/, /u/, /æ/ and /ɑ/, and whether vowels that are acoustically close in formant space (e.g., the pairs /i/-/I/ and /e/-/ɛ/) are distinguishable by tongue sensor position. Data were recorded for ten talkers. Points taken at the vowel midpoint of each production were plotted to determine the spatial separation (Euclidean distance) between each vowel region (centroid). Preliminary results suggest TB sensors yield the most discriminable patterns for corner vowels. Tense/lax pairs show smaller differences, as predicted by acoustic theory. For most vowel contrasts examined, patterns of spatial separation appeared sufficient for real-time feedback applications.
Gradient prosodic boundary perception and recursion in syntactic disambiguation
Authors: Castellucci Gregg A. , Goldenberg Dolly
Published: May 2014

Most research examining prosodic structure has made the assumption that prosodic boundaries are categorical and discrete, and all instances of a specific category are linguistically equivalent (Snedeker and Casserly, 2010). The empirical evidence for this notion is the finding that certain within-category differences do not cause changes in attachment ambiguity (Carlson et al., 2001, experiment 2). However, several studies have shown that prosodic boundaries which arguably instantiate the same category are not only produced differently (Ladd, 1988, 2008; Krivokapić and Byrd, 2012), but listeners are also sensitive to variations in production within categories (Wagner and Crivellaro, 2010; Krivokapić and Byrd, 2012). Such findings suggest that, contrary to traditional assumptions, a certain degree of recursion may exist in prosodic structure. Our study further examines this controversial concept, as we test whether listeners are able to differentiate various meanings of coordinative structures using gradient strengths of a single boundary type while holding all other variables constant. If prosodic structure is non-recursive and phonetic gradiency within a certain boundary category is not linguistically meaningful listeners should not be able to perform this task. However, listeners in this study were able to successfully differentiate coordinative structures based on within-category boundary strength alone.
Automatic analysis of emotional intonation in Brazilian Portuguese
Authors: Netto Waldemar F. , Peres Daniel O. , Martins Marcus M. , Vieira Maressa F.
Published: May 2014

This study analyzes emotional speech (anger, sadness, and neutral) in Brazilian Portuguese by testing 13 acoustical parameters, which were automatically processed by the software ExProsodia. The data analyzed consisted of excerpts of spontaneous speech of male and female subjects which were collected on Internet. The software selected Intonation Units (IU) based on fundamental frequency (FO), duration, and intensity information. A pilot test was carried out and its result showed that five out of 13 parameters analyzed were statically significant: skewness of fundamental frequency—sF0; coefficient of variation of fundamental frequency—cvF0; difference between medium tone and IU value—dMTIU; standard deviation of intonation unit—sdIU; and coefficient of variation of positive focus/emphasis values (above MT)—cvposF/E. A two-way ANOVA test showed a significant result. A Tukey's HSD test pointed out to differences between anger and other emotions in both genres. A significant difference between genres was found only in sadness. A Cluster test was performed based on the acoustic parameters taken into consideration and showed that only anger (male and female) could be described based on these parameters. Regarding gender differences, only sadness and neutral speech could be clustered. The results indicate that the automatic analysis done by ExProsodia can be a reliable way to analyze emotional speech produced by male and female subjects.
Machine classification versus human judgment of misarticulated pediatric speech
Authors: Ratnagiri Madhavi , Nagao Kyoko , Krieger Sara , Vallino Linda , Bunnell H. Timothy
Published: May 2014

In this study, we compared machine classification to expert human judgments of segments produced by children with speech sound disorders and typically developing children. Stimuli were presented for classification in a five-alternative forced-choice paradigm with the target segment presented either in isolation or in word context. The phonemes we were mainly interested in were /s/ and /ʃ/, but instances of /θ/, /t/ and /f/ were also included among the stimuli since they could be confused with some error productions. Experienced speech language pathologists identified the target phonemes in both context conditions and their judgments were compared to the results of an HMM classifier that was trained on the speech of typically developing children. For segments presented in context, percentage agreement between the machine classifier and the consensus human classification was 95.83%. For segments presented in isolation, agreement dropped to 87.29%. Thus, the machine classifier responded more like human listeners responding to segments in word context rather than in isolation. An analysis of the differences between specific stimuli responsible for the lower agreement with isolated segments will be presented.
A comparison study of emotional speech articulations using the principal component analysis method
Authors: Lee Sungbok , Kim Jangwon , Narayanan Shrikanth
Published: May 2014

In this study, we will investigate differences in the tongue movements across emotions by utilizing the principal component analysis (PCA), which enables to detect major and minor variations in the entire tongue surface movements under different speaking conditions. For the purpose of the study, we analyze an acted emotional speech production corpus collected from one actor and two actresses using an electromagnetic articulography (EMA). Discrete emotion types considered in this study are anger, sadness, and happiness as well as neutral one as reference. Specifically, we will investigate the number of principal components that are needed to capture emotional variations, and the differences in tongue shaping across different emotion types. Outcome of the study would provide supplementary information to the previous PCA-based production studies which have mainly focused on normal, or neutral, speech articulation. Major principal components that are found in the study also can be utilized as a basis by which effective but compact articulatory correlates (i.e., component scores) can be derived for a further investigation of emotional speech production such as an interaction between articulatory kinematics and prosodic modulations of pitch and loudness patterns, which is another important motivation of the study.
Blind deconvolution of extended duration underwater signals
Authors: Kim Jane H. , Dowling David R.
Published: May 2014

Synthetic time reversal (STR) is a passive blind deconvolution technique for estimating the original source signal and the source-to-array impulse responses in an unknown multipath sound channel. Previous investigations of STR involved relatively short duration chirp signals (50 ms) where the assumption of a static underwater sound channel was acceptable. However, the static-channel assumption is inadequate for longer duration underwater acoustic communication signals lasting one or more seconds. Here, wave-driven changes in the ocean's surface shape and water-column sound speed lead to significant temporal variations in the source-to-array impulse responses. This presentation describes an effort to accommodate such temporal variations by decomposing a long duration signal into smaller overlapping pieces, applying STR to each piece, and then stitching the resulting sequence of signal estimates together to blindly recover the original long-duration signal. Simulations of a one-second-duration synthetic signal propagating in a static underwater sound channel to a 16-element vertical array are used to determine how the technique's performance depends on the duration and overlap of the signal pieces in relation to the signal's bit rate and the sound channel's time-delay spread. Extension of this effort to recordings from dynamic sound channels is anticipated. [Sponsored by the Office of Naval Research.]
A simulation based study of the effective signal to noise ratio of broadband underwater acoustic communications between moving platforms
Authors: Joshi Shrey , Gendron Paul J.
Published: May 2014

Characterization of the effective signal to noise ratio (eSNR) of broadband underwater acoustic environments as a function of platform motion provides a practical and useful predictive metric of the adversity of an acoustic communication channel. Presented here is an analysis of estimated and actual eSNR associated with diverse moving platform scenarios for the practical case of an acoustic response function modeled as a Gauss-Markov process. A ray model of the arrival structure of various refractive environments along with a set of canonical motion scenarios provides a space of time-varying channel operators that captures the bulk effects of platform motion. Considered here are various superpositions of elliptical and translational motion effects. It is demonstrated that the eSNR exhibits both a low SNR gap and a high SNR ceiling relative to the actual received SNR (rSNR). These results give insight into useful source power levels and provide a correspondence between coherence degradation and vehicle speed and acceleration rates. These model based results lend credence to previous observations of eSNR made from high frequency broadband underwater acoustic observations [2008 NRL Review, pp. 123–125], [J. Acoust. Soc. Am. 130(4), (2011)].
Development of a high frequency underwater acoustic communication modem
Authors: Paradis Brady , Bachand Corey , Gendron Paul , Brown David A.
Published: May 2014

The development of a high frequency (300 kHz) underwater acoustic communication modem is reported. The transmit and data acquisition components have been designed for QPSK waveforms, intended to be computationally simple, power efficient, and cost effective. Applicability to other types of waveforms will be discussed. The design incorporates a digital signal processor, an efficient power amplifier, an analog to digital converter, and broadband transducers. An electrical equivalent circuit of the transducer was constructed as an accurate test load for bench-top measurements. Modeled results are compared to in-water test tank measurements with broadband transducers. The system is intended to serve as a development and demonstration platform to test novel waveforms and serve as a communication system on unmanned underwater vehicles (UUVs).
Fuzzy statistical normalization constant false alarm rate detector for non-Rayleigh sonar data
Authors: Xu Yanwei , Hou Chaohuan , Yan Shefeng , Li Jun
Published: May 2014

A new CFAR detector for non-Rayleigh data based on fuzzy statistical normalization is proposed. The proposed detector carries out the detection with two stages. The first stage of the fuzzy statistical normalization CFAR Processor is background level estimation based on fuzzy statistical normalization. The second stage is signal detection based on the original data and the defuzzification normalized data. Performance comparisons are carried out to validate the superiority of the proposed CFAR detector.