bluuebunny/crossref_metadata_2025 huggingface dataset:
Sound absorbing vertically retracting drapery: A comparative study
Authors: Lamour Liz L. , Bridgewater Ben , Brooks Ben
Published: October 2011

The use of drapery as a variable sound absorbing material is widespread in theaters, university music halls, and other spaces where variable reverberation time is desired. As a class project at The University of Kansas, the authors and their classmates tested two types of sound absorbing vertically retracting drapery manufactured by a theatrical contracting firm using reverberant room methods. Fabric used in these two tests was cotton velour and acrylic velour. Coefficients of absorption were compared with coefficients of absorption published by a firm specializing in the fabrication of vertically retracting sound absorbing velour drapery. The measured and published data allowed both types of vertical retracting drapery to be specified for a multipurpose auditorium renovation project at a college in Kansas. The college auditorium renovation project will use the drapery fabricated by the specialty firm and the on-site determined coefficients of absorption will be presented and compared with the manufacturer's published data and also compared with the data obtained in the reverberant room for the somewhat different retracting drapery design by the theatre contracting firm. And if it proves to be possible, the on-site sound absorption measurements will be made at another college auditorium which uses cotton velour retracting drapery produced by the theatrical contracting firm. These data will be useful in specifying sound absorbing vertically retracting drapery for future projects.
Diel and lunar variations of marine ambient sound in the North Pacific
Authors: Baumann-Pickering Simone , Širović Ana , Roch Marie A. , Simonis Anne E. , Wiggins Sean M. , Oleson Erin M. , Hildebrand John A.
Published: October 2011

Marine ambient sound was recorded on autonomous high-frequency acoustic recording packages (bandwidth 10 Hz to 100 kHz) during long term deployments at multiple sites across the North Pacific, from the high latitude Aleutian Islands to tropical Palmyra Atoll in depths of 600–1 000 m. Most intertropical but no temperate locations showed a distinct diel pattern in ambient sound. The soundscape at each location was unique, yet there was a similar recurring sound of unknown origin in lower latitude locations. This sound had a peak frequency around 3–5 kHz and was recorded only for several hours after sunset. Additionally, at some locations, a broadband acoustic signal with bandwidth up to 60 kHz was recorded at night with crepuscular peaks. Both sound patterns were lunar dependent with lower acoustic levels during full moon phases. Site-specific diel and seasonal acoustic patterns have been observed for various odontocete species. Correlations between odontocete presence and levels of ambient sound are investigated. [Work supported by NOAA-Pacific Islands Fisheries Science Center, US Navy-N45/PACFLT, ONR, Pacific Life, Ocean Foundation, University of California, San Diego.]
Long-term passive acoustic monitoring of nearshore ecosystems in the Northwestern Hawaiian Islands
Authors: Lammers Marc O. , Munger Lisa , Fisher Pool Pollyanna , Wong Kevin , Au Whitlow W. L. , Brainard Russell E.
Published: October 2011

Monitoring the changing state of marine habitats in remote areas is, in most cases, a challenging task due to limited and/or infrequent opportunities to make direct observations. Passive acoustic monitoring is sometimes the best means of establishing long-term biological trends in such areas. Since 2006, an effort has been underway to monitor the neashore ecosystems of the Northwestern Hawaiian Islands (NWHI) using a network of Ecological Acoustic Recorders. A wide range of acoustic signals are being monitored to infer biological trends and to gauge the relative stability of the ecosystem. Among the variables measured are the acoustic activity of snapping shrimp, the incidence of cetaceans and the extent of spectral and temporal partitioning of the acoustic space by different taxa, measured as the “acoustic entropy” of the habitat. Multiyear time series of the different measures provide baseline levels of biological activity at each location and also reveal periods of anomaly. Observed trends are then examined for corollary relationships with oceanographic and meteorological parameters measured both in situ and remotely. The data obtained thus far are providing valuable insights that will help assess the long-term response of ecosystem in the NWHI to both natural and anthropogenic factors
Investigation on the effect of specular reflections from stone surface on twinkling artifact
Authors: Lu Wei , Sapozhnikov Oleg A. , Kucewicz John C. , Cunitz Bryan W. , Kaczkowski Peter J. , Crum Lawrence A. , Bailey Michael R.
Published: October 2011

The twinkling artifact can highlight kidney stones during ultrasound color Doppler imaging with high sensitivity for stone detection. The mechanism of the twinkling artifact is still under debate. It was reported previously that twinkling appeared distal to the echogenic reflection from the stone surface in cases with no signal saturation. [Lu etal., JASA 129(4), p. 2376]. In this report, the effect of specular reflections on twinkling was investigated. Human kidney stones (5-9 mm in length) were embedded in a polyacrylamide gel phantom. Radio-frequency (RF) data were recorded from pulse-echo ensembles using a software-programmable ultrasound system. The variability within the beamformed Doppler ensemble, which is responsible for twinkling, was traced back to the unbeamformed RF channel data to identify whether variability arose disproportionately on channels receiving the specular reflection. The results showed that the specular reflection did not saturate individual channels and that the variability was observed on most channels with similar magnitude, which indicates that the appearance of twinkling does not rely on the specular reflection from the stone surface. Instead in the beamformer, the varying signals have the appearance of arising from a point source within the stone. [Work supported by NIH DK43881, DK086371, DK092197, and NSBRI through NASA NCC 9-58.]
Use of highly nonlinear solitary waves for the assessment of dental implants
Authors: Berhanu Bruk
Published: October 2011

This paper presents a noninvasive technique based on the propagation of highly nonlinear solitary waves (HNSWs) to monitor the stability of dental implants. HNSWs are mechanical waves that can form and travel in highly nonlinear systems, such as one-dimensional chains of contacting spherical particles (i.e., granular crystals). In this study, a granular crystal-based actuator/sensor, designed and built at the University of Pittsburgh, was used to introduce HNSWs into dummy implants that were inserted into either hardened plaster or treated beef bones. The waves reflected at the interface between the particle and implant were monitored to estimate the change in stiffness of the material. The hydration of the plaster was monitored because it can be considered largely similar to the osseointegration process that occurs in the oral connective tissue once a dental-endosteal threaded implant is surgically inserted. In the experiment using bone, the implant-bone system was immersed in an acid bath causing decalcification of the bone and, therefore, reduced stiffness of the bone itself, simulating the inverse of osseointegration. Positive correlations were found, in both experiments, between certain properties of the HNSWs and the stiffness of the test object, demonstrating that HNSWs show promise for use in assessment of dental implants.
Cough count as a marker for patient recovery from pulmonary tuberculosis
Authors: Tracey Brian H. , Comina German , Larson Sandra , Bravard Marjory , Lopez Jose W. , Gilman Robert H.
Published: October 2011

In regions of the world where tuberculosis (TB) poses the greatest disease burden, clinicians often lack access to skilled laboratories. This is particularly problematic for patients with drug-resistant tuberculosis, as these patients will otherwise receive standard TB medication and will not respond to treatment. Thus, a lab-free method for assessing patient recovery during treatment would be of great benefit. We hypothesize that cough analysis may provide such a test, and have carried out a pilot study to record coughs from a cohort of patients in Lima, Peru. We describe algorithm development for cough data analysis and compare several event detection and classification strategies. Results from our ongoing validation efforts suggest that cough count (cough/hour) decreases noticeably after the start of treatment in drug-responsive patients. Our long-term goal is development of a low-cost ambulatory cough analysis system that will help identify patients with drug-resistant tuberculosis.
Vector sensors for airborne surveillance applications
Authors: McConnell James , Jensen Scott , McCormick Thomas , Woolrich Brendan
Published: October 2011

The use of vector sensors for airborne surveillance applications (e.g., frequencies below 500 Hz) is discussed with emphasis on transducers that measure the acoustic pressure-gradient. Traditional approaches such as ribbon microphones, hot-wire anemometers, and finite-difference techniques will be reviewed. The crux of the presentation concerns a discussion of diffraction type pressure-gradient microphones that go beyond the classic ribbon microphone and utilize large format membrane transduction elements comprised of piezoelectric and electret materials. The results of analytical, numerical, and experimental evaluations will be presented.
Analysis of the advantages and complexities of acoustic vector sensor arrays
Authors: Poulsen Andrew J. , Baggeroer Arthur B.
Published: October 2011

The hydrophone, an omnidirectional underwater microphone, is the most common sensor for listening to underwater sound. Directional sensors, however, have many important applications. Acoustic vector sensors, one important class of directional sensors, measure acoustic scalar pressure along with acoustic particle motion. With this additional vector measurement, vector sensors feature many advantages over conventional omnidirectional hydrophone sensors: improved array gain/detection performance, enhanced bearing resolution, the ability to “undersample” an acoustic wave without spatial aliasing, and the capability of attenuating spatial ambiguity lobes, e.g., left/right ambiguity resolution for a linear array. Along with their advantages, however, vector sensors also pose additional practical complexities: greater sensitivity to non-acoustic, motion-induced flow noise at low frequencies, requisite knowledge/measurement of each sensor's orientation, management of different sensor types (pressure and particle motion) that each with different noise properties/calibration requirements, and adaptive processing can become difficult in a snapshot limited regime since each vector sensor is made up of up to four data channels. This paper will explore the virtues and limitations of vector sensor arrays in the presence of realistic ocean noise fields and system imperfections, including their effects on array performance (gain, beampatterns, etc.) supported by theoretical analysis and illustrative examples.
Capacity and statistics of measured underwater acoustic particle velocity channels
Authors: Guo Huaihai , Chen Chen , Abdi Ali , Song Aijun , Badiey Mohsen , Hursky Paul
Published: October 2011

Acoustic particle velocity channels can be used for communication in underwater systems [A. Abdi and H. Guo, IEEE Trans. Wireless Communi. 8, 3326–3329, (2009)]. In this paper, the information (Shannon) capacity of underwater acoustic particle velocity channels is studied using measured data. More specifically, the maximum achievable data rates of a compact vector sensor communication receiver and another communication receiver with spatially separated scalar sensors are compared. Some statistics of particle velocity channels such as amplitude distribution and power delay profile are investigated using measured data and proper models are suggested as well. The results are useful for design and simulation of vector sensor underwater communication systems in particle velocity channels. The work is supported in part by the National Science Foundation (NSF), Grant CCF-0830190.
Overview of the Ares I scale model test program
Authors: Counter Douglas D. , Houstion Janice
Published: October 2011

Launch environments, such as lift-off acoustic (LOA) and ignition overpressure (IOP), are important design factors for any vehicle and are dependent upon the design of both the vehicle and the ground systems. LOA environments are used directly in the development of vehicle vibro-acoustic environments and IOP is used in the loads assessment. The NASA Constellation Program had several risks to the development of the Ares I vehicle linked to LOA. The risks included cost, schedule, and technical impacts for component qualification due to high predicted vibro-acoustic environments. One solution is to mitigate the environment at the component level. However, where the environment is too severe for component survivability, reduction of the environment itself is required. The Ares I scale model acoustic test (ASMAT) program was implemented to verify the Ares I LOA and IOP environments for the vehicle and ground systems including the mobile launcher (ML) and tower. An additional objective was to determine the acoustic reduction for the LOA environment with an above deck water sound suppression system. ASMAT was a development test performed at the Marshall Space Flight Center (MSFC) East Test Area (ETA) Test Stand 116 (TS 116). The ASMAT program is described in this presentation.
Recovering the spatial correlation of liftoff acoustics from the Ares Scale Model Acoustics Test
Authors: Prock Brian , Bremner Paul , Philley Thomas L.
Published: October 2011

Accurately predicting structural vibrations due to acoustic loads requires knowledge about the overall sound pressure levels, the amplitude of the sound pressure levels as a function of frequency (auto-spectra), and the spatial correlation of the sound pressure levels (cross-spectra). When dealing with the liftoff acoustics of launch vehicles, a large amount of historical data is available in terms of overall levels and auto-spectra, but only a limited amount of data exists for cross-spectra. ATA Engineering has used data taken during NASAs Ares Scale Model Acoustic Test to recover the spatial correlation of liftoff acoustics for a typical launch vehicle. By assuming the measured liftoff acoustics that are a combination of propagating waves and diffuse acoustic fields, curve-fitting algorithms are used to recover spatial correlation parameters required by modern vibro-acoustic analysis software.
5% Ares I scale model acoustic test: Overpressure characterization and analysis
Authors: Alvord David , Casiano Matthew , McDaniels David
Published: October 2011

During the ignition of a ducted solid rocket motor (SRM), rapid expansion of injected hot gases from the motor into a confined volume causes the development of a steep fronted wave. This low frequency transient wave propagates outward from the exhaust duct, impinging the vehicle and ground structures. An unsuppressed overpressure wave can potentially cause modal excitation in the structures and vehicle, subsequently leading to damage. This presentation details the ignition transient findings from the 5% Ares I scale model acoustic test (ASMAT). The primary events of the ignition transient environment induced by the SRM are the ignition overpressure (IOP), duct overpressure (DOP), and source overpressure (SOP). The resulting observations include successful knockdown of the IOP environment through use of a space shuttle derived IOP suppression system, a potential load applied to the vehicle stemming from instantaneous asymmetrical IOP and DOP wave impingement, and launch complex geometric influences on the environment. The results are scaled to a full-scale Ares I equivalent and compared with heritage data including Ares I-X and both suppressed and unsuppressed space shuttle IOP environments.
Simulation of acoustics for Ares I scale model acoustic tests
Authors: Putnam Gabriel C. , Strutzenburg Louise L.
Published: October 2011

The Ares I scale model acoustics test (ASMAT) is a series of live-fire tests of scaled rocket motors meant to simulate the conditions of the Ares I launch configuration. These tests have provided a well documented set of high fidelity acoustic measurements useful for validation including data taken over a range of test conditions and containing phenomena like ignition over-pressure and water suppression of acoustics. To take advantage of this data, a digital representation of the ASMAT test setup has been constructed and test firings of the motor have been simulated using the Loci/CHEM computational fluid dynamics software. Results from ASMAT simulations with the rocket in both held down and elevated configurations, as well as with and without water suppression have been compared to acoustic data collected from similar live-fire tests. Results of acoustic comparisons have shown good correlation with the amplitude and temporal shape of pressure features and reasonable spectral accuracy up to approximately 1000 Hz. Major plume and acoustic features have been well captured including the plume shock structure, the igniter pulse transient, and the ignition overpressure.
Validation study on computational aeroacoustics of acoustic waves from sub-scale rocket plumes
Authors: Morizawa Seiichiro , Nonomura Taku , Tsutsumi Seiji , Yamanishi Nobuhiro , Terashima Keita , Obayashi Shigeru , Fujii Kozo
Published: October 2011

In this paper, the comparative study of prediction based on computational aeroacoustics (CAA) and experimental results for acoustic waves from modeled rocket motors is conducted, and prediction accuracy of CAA is discussed in the framework of JAXA-CNES collaboration. Experimental data of flow and acoustic fields of solid motor by JAXA and H2-AIR liquid motor by CNES are used as the reference. Two types of computational codes are adapted in this study. The predictions of sound pressure level by both computational codes agree reasonably with corresponding experimental data, whereas the errors are approximately less than 5 dB. In addition, each aeroacoustic field of CAA results in this study is discussed in detail.
Mistuned harmonic detection and the role of tonotopically local neural synchrony
Authors: Hartmann William M.
Published: October 2011

A mistuned harmonic in an otherwise periodic complex tone is a simple stimulus for the study of segregation and integration of complex tones by human listeners. In a mistuned harmonic detection experiment, a listener must discriminate between two tones—one perfectly periodic and the other with a mistuned harmonic. This detection paradigm is subject to known artifacts. However, with careful experiment design the artifacts can be controlled, and the paradigm becomes an efficient way to explore the emergence of segregated mistuned spectral components. The results of mistuned harmonic detection experiments support a tonotopically local model in which detection is mediated by the dephasing of a neural spike sequence in a tonotopically tuned channel. Evidence for this model comes from (1) the functional dependences of detectability on the amount of mistuning and the tone duration, (2) the non-monotonic level dependence of detectability, (3) the lowpass character of detection—indicating an essential role for neural synchrony, and (4) the need for tonotopically local interaction as evidenced by experiments using mistuned distracters, mistuned harmonics in spectral gaps, and dichotic presentation. [Work supported by the NIDCD and the AFOSR.]
Parametric issues in measuring the olivocochlear reflex with a masking technique
Authors: Roverud Elin M. , Strickland Elizabeth A.
Published: October 2011

Previous studies in this laboratory have suggested that forward masking occurs by two mechanisms, excitatory masking and gain reduction via the medial olivocochlear reflex (MOCR), that operate over different time courses. In this laboratory, a forward masking technique is used in which a precursor, intended to elicit the MOCR, is followed by a fixed off-frequency forward masker and signal. A prior study [Roverud and Strickland, J. Acoust. Soc. Am. 128, 1203–1214] found that for short precursors, signal threshold increased then decreased (buildup) as the signal and masker were delayed from the precursor. This result could be consistent with the sluggish onset of the MOCR. When the masker is removed, however, buildup is not observed as the signal is delayed from a precursor, even though the precursor should still be eliciting the MOCR. This raises the question, what is the role of the masker and why is it necessary to observe buildup? The current study examines the frequency and level characteristics of the masker required to observe the buildup effect. Results will be discussed in terms of gain reduction and temporal window models of forward masking. [Research supported by a Grant from NIH(NIDCD) R01 DC008327.]
Perceiving auditory distance using level and direct-to-reverberant ratio cues
Authors: Kolarik Andrew J. , Cirstea Silvia , Pardhan Shahina
Published: October 2011

The study investigated how level and reverberation cues contribute to distance discrimination, and how accuracy is affected by reverberation cue strength. Sentence pairs were presented at distances between 1 and 8 m in a virtual room simulated using an image-source model and two reverberation settings (lower and higher). Listeners performed discrimination judgments in three conditions: level cue only (Level-Only), reverberation only (Equalized), and both cues available (Normal). Percentage correct judgment of which sentence was closer was measured. Optimal distance discrimination was obtained in the Normal condition. Perception of the difference in distance between sentences had a lower threshold (i.e., performance was significantly better, p<0.05) for closer than further targets in Normal and Level-Only conditions. On the contrary, in the Equalized condition, these thresholds were lower for further than closer targets. Thresholds were lower at higher reverberation in the Equalized condition, and for further targets in the Normal condition. Data indicate that level generally provided more accurate discrimination information than direct-to-reverberant ratio. Direct-to-reverberant ratio provided better information for sounds further from the listener than for nearer sounds, and listeners were able to use direct-to-reverberant ratio as effectively as level in highly reverberant rooms when discriminating far sound sources.
Infants' vowel discrimination in modulated noise
Authors: Werner Lynne A.
Published: October 2011

Adult listeners detect and discriminate target sounds better in amplitude modulated noise than in unmodulated noise. This study examined infants' ability to take advantage of masker modulation to improve sensitivity to a target. Listeners were 7–9-month-old infants and 18–30-year-old adults. Vowel discrimination in noise was tested. Listeners learned to respond when a repeated vowel changed from /a/ to /i/ or from /i/ to /a/. An observer-based method was used to assess sensitivity to the vowel change. The maskers were speech-spectrum noise either unmodulated, amplitude modulated with the envelope of single-talker speech or sinusoidally amplitude modulated at 8 Hz with a 75% modulation depth. The overall level of the maskers was 60 dB SPL. The level of the vowels, chosen to yield an average d' of 1 in the unmodulated masker, was 46 dB SPL for adults and 58 dB SPL for infants. Adults' d' was substantially and significantly higher in both modulated maskers than in the unmodulated masker. Infants' d' was also significantly higher in the two modulated maskers than in the unmodulated masker, but the improvement due to modulation was significantly smaller for infants than for adults. [Work supported by NIDCD R01DC00396 and P30DC04661.]
Psychological factors influencing the evaluation of electric vehicle interior noise
Authors: Steffens Jochen , Kueppers Thomas , Skoda Sabrina
Published: October 2011

Increasing global awareness of the benefits of electromobility has brought about the need for new concepts in terms of the acoustic design of future vehicle generations. This includes both the creative design process and the development of suitable methods for the subjective evaluation of target sounds. The main difference between e-car sound surveys and those carried out on familiar sound categories is the potential consumer's lack of experience with electric vehicles. Thus, the consumer has no, or very unspecific, expectations in this regard. Several studies have shown that many subjects have to construct their personal frame of reference for evaluation within the listening experiment. However, this is possibly at odds with experience-based expectations relating to sounds of conventional combustion engines. The result is a conflict of objectives between the traditional and the modern, familiarity and strangeness, and not least between driving freedom and ecological awareness. In this context, the authenticity of the sound and the subjective interpretability of the sound information also appear as moderator variables. Moreover, associations with other vehicle categories, for example, streetcars, also influence the perceived sound quality. Within this contribution, these factors will be expounded and their influence on the evaluation of interior noise discussed.
Auditory-proprioceptive interaction—How do acceleration forces influence the evaluation of driving sounds?
Authors: Skoda Sabrina , Steffens Jochen , Kueppers Thomas , Becker-Schweitzer Joerg
Published: October 2011

One fundamental requirement for a widespread use of electric powered vehicles is a high degree of social acceptance of alternative drive concepts. As part of this, perception and evaluation of comfort and quality in a vehicle become increasingly important. The customers' judgment on these factors is strongly influenced by the noise and vibration behavior of the vehicle and always is passed in the context of multiple sensory impressions which are processed in the human brain consciously and unconsciously. The interaction mechanisms of sensory perception are highly complex and raise several scientific questions. During the past years, valuable insights about the interaction of visual and auditory perception have been obtained and there are also a number of theories about the auditory-tactile interaction. In contrast, the connection between auditory and proprioceptive perception remains largely unexplored. This paper deals with the question how acceleration forces influence human auditory perception. In order to make evident possible crossmodal effects, a listening experiment was conducted in different kinds of driving simulators. The results of this study will be presented and discussed.
Selection of speech/voice vectors in forensic voice identification
Authors: Harnsberger James , Hollien Harry
Published: October 2011

The case for the use of speech/voice vectors in speaker identification was made by Hollien and Harnsberger (2010). Those vectors found most robust in capturing speaker-specific characteristics were voice quality, vowel quality, speaking fundamental frequency, and temporal features. In this study, the speech cues for each of the four vectors will be compared to each other with respect to their predictive power. In addition, different vector algorithms and/or processing approaches for each will be contrasted in terms of their effects on identification robustness. One example is conversion of the vowel formant frequencies and bandwidth measurements to geometric scaling (semits). Finally, a second dataset of 18 male voices obtained from evidence recordings, paired with exemplars recorded from a speaker pool, were used to test a modified form of this speech/voice vector approach. The data from these subjects will be compared to those from the 1993 study (substantial improvement) and those from the 2010 experiment (confirmation).
Defining the default defense hypothesis in likelihood-ratio forensic voice comparison
Authors: Ochoa Felipe , Morrison Geoffrey Stewart
Published: October 2011

In forensic DNA comparison, the person submitting samples for evaluation does not know what properties the samples will have when they are analyzed at the laboratory; samples are submitted as a matter of routine. In contrast, in forensic voice comparison the decision to submit samples for evaluation is based on prior screening: Typically a police officer, a lay person with respect to forensic voice comparison, has listened to the questioned-speaker recording and the known-speaker recording and decided that they sound sufficiently similar that they could be the same speaker and merit evaluation by a forensic scientist. If they do not sound sufficiently similar they are not submitted for evaluation. Unless the defense proposes a more restrictive hypothesis, the forensic scientist should therefore adopt the following as the default defense hypothesis and select a background database accordingly: The known speaker is not the same person as the questioned speaker but is one member of a population of speakers whom to a lay person sound sufficiently similar to the voice on the questioned-voice recording that they would submit recordings of these speakers for forensic comparison with the questioned-voice recording. Examples of how this theory might be applied are discussed.
Investigating the acoustic and phonetic correlates of deceptive speech
Authors: Kirchhuebel C.
Published: October 2011

The following study describes an initial investigation into the acoustic and phonetic correlates of deceptive speech using auditory and acoustic analysis. Due to the lack of extant data suitable for acoustic analysis, a laboratory-based experiment was designed which employed a mock-theft paradigm in conjunction with a “security interview” to elicit truthful and deceptive speech as well as control data from a total of ten male native British English speakers. Using Praat, the control, truthful, and deceptive speech samples were analyzed on a range of speech parameters including f0 mean and variability, intensity, vowel formant frequencies, and speaking/articulation rate. Preliminary analysis suggests that truth-tellers and liars cannot be differentiated based on these speech parameters. Not only was there a lack of significant changes for the majority of parameters investigated but also, if change was present it failed to reveal consistencies within and between speakers. The remarkable amount of inter and intra-speaker variability underlines the fact that deceptive behavior is individualized and very multifaceted. As well as providing a basis for future research programs, the present study should encourage researchers and practitioners to evaluate critically what is (im)possible using auditory and machine based analyses with respect to detecting deception from speech.
Detailed study of articulatory kinematics of critical articulators and dependent articulators of emotional speech
Authors: Kim Jangwon , Lee Sungbok , Narayanan Shrikanth
Published: October 2011

This study investigates the articulatory kinematics of critical articulators and dependent articulators as a function of emotion. Our hypothesis is that critical articulators and dependent articulators are utilized differently for achieving distinctive emotion goals that overlay linguistic goals. For example, speakers may use variability of dependent articulators distinctively to that of critical articulators in achieving emotion goals. Distinctive articulatory movements for different emotions have been observed (Lee etal. 2005). This study uses a database of three speakers (2 female and 1 male) collected with electromagnetic articulography to collect kinematic information. Articulatory trajectories are aligned by dynamic time warping. Linguistically identical syllable-level segments are analyzed based on detailed aspects of articulatory movements (e.g., position, velocity and phase), after sampling with a 20-ms window and 10-ms shifting. The emotion-specific patterns that emerge for critical (i.e., goal-directed) articulators are compared to those for articulators that are not under overt control for a particular phone. [Work supported by NIH and NSF Grants.]
When inferring lingual gestures from acoustic data goes wrong: The case of high vowels in Canadian French
Authors: Dalton Will
Published: October 2011

Canadian French (CF) is distinguished from other dialects partly by the presence of lax high vowel allophones in closed syllables (Walker, 1984). Acoustically, tense high vowels are characterized by a lower F1 than their lax counterparts, which could be the result of tongue root advancement, tongue body raising, or both (Ladefoged & Maddieson, 1996). High vowel allophony in CF therefore represents a case in which articulatory gestures cannot reliably be inferred from acoustic data alone. Nevertheless, the literature discussing the phonetic properties of high vowels in CF commonly assumes tongue root position to be the parameter that distinguishes between tense and lax vowels, despite an absence of empirical evidence. The purpose of this experiment is to test this assumption and provide articulatory evidence using ultrasound imaging to examine tongue position during speech production by CF speakers. Results indicate that an advanced tongue root gesture is not used to distinguish between high vowels in CF; no significant difference in tongue root position was found between tense and lax allophones. Rather, tongue body height was found to be the distinguishing feature. These findings contribute to our knowledge of the typology of articulatory gestures used to distinguish between so-called tense and lax vowels.
Nonlinear viscoelastic properties of human vocal fold tissues under large-amplitude oscillatory shear
Authors: Naseri Elhum , Du Mindy , Chan Roger W.
Published: October 2011

Traditionally, viscoelastic shear properties of human vocal fold tissues have been described by the linear viscoelastic moduli G' and G” at small strain amplitudes. However, once the mechanical behavior becomes nonlinear these moduli are no longer sufficient for viscoelastic characterization. MITlaos, a rheological framework developed for better describing such behavior, was used to characterize the nonlinear viscoelastic properties of the vocal fold lamina propria when subjected to large-amplitude oscillatory shear (LAOS). MITlaos involved Fourier transform processing to convert raw stress–strain signals into a filtered/smoothed total stress signal based on the odd-integer harmonic components, with nonlinear viscoelastic parameters simultaneously derived. Rheometric testing of vocal fold cover specimens was performed with increasing strain amplitudes using a controlled-strain, simple-shear rheometer. Smoothed Lissajous–Bowditch curves generated from MITlaos were plotted in Pipkin space, and the nonlinear analysis was summarized by variations of rheological fingerprints. Pipkin diagrams served as a geometric means for identifying the onset of nonlinear behavior, and any distortions due to noise. Results showed that the human vocal fold cover when subjected to LAOS demonstrated intracycle strain stiffening and intercycle strain softening with increasing strain amplitude, as well as shear thinning with increasing strain-rate amplitude. [Work supported by NIH.]
Acoustic correlates of narrow focus in Turkish
Authors: Ipek Canan
Published: October 2011

Acoustic correlates of narrow focus in Turkish focus is known to affect the acoustic properties of the lexical element under focus. Its effect on the pre-focus and post-focus domains has attracted much less attention. This study aims to investigate the acoustic changes as a function of focus in the pre-focus and post-focus domains as well as in the on-focus domain in Turkish and listeners' sensitivity to those changes in retrieving information from the acoustic signal. For this purpose, a production and a perception experiments have been conducted. For the production study, speakers read sentences in which the location of focus was manipulated via wh-questions preceding those sentences. For the perception study, listeners heard selected sentences recorded for the production study and were asked to judge the prominent word in the sentence. Results showed that focused words had increased duration and intensity, and post-focus words had reduced F0, duration and intensity. Interestingly, pre-focus words were found to have increased F0 and duration. Listeners' identification of focus was positively affected by the presence of acoustic changes especially in the post-focus domain. These findings have implications for speech perception and modelling prosody.
Modeling imperatives in Spanish
Authors: Robles-Puente Sergio
Published: October 2011

The intonation of imperatives in Spanish has traditionally been considered to not differ systematically from that of declaratives. This study shows that given the appropriate contexts, imperatives can exhibit unique phonetic properties. Nine speakers of Peninsular Spanish produced imperatives in response to instructions that elicited different levels of imperativity, along with control declarative items. Results show that while imperatives may fail to differ from declaratives in some conditions, when the context requires a stronger imperative, speakers use intonational configurations not found in declaratives. These include higher F0 values and changes in the overall pitch contour with higher F0 values toward the end of the sentence, different boundary tones and different F0 peak alignments. A perceptual experiment with 13 speakers confirmed the relevance of these intonational modulations by demonstrating that the strategies that were more commonly used in the production experiment were preferred over others to express imperativity. Results can be modeled within the framework of grammar dynamics (Gafos and Benus, 2006. Cognitive Science, 30, 837–862). [This research was supported by the University of Southern California Del Amo Foundation.]
Transport equation approach for second order mode statistics in an ocean with random sound speed perturbations: Coherence
Authors: Colosi John , Chandrayadula Tarun
Published: October 2011

A transport equation has been derived to describe the range evolution of the single frequency cross mode coherence matrix so that acoustic field coherence functions with temporal as well as depth and transverse separations can be easily computed. The theory assumes 2-D propagation in the depth range plane, small angle weak multiple forward scattering, and the Markov approximation, and it has been previously shown to accurately predict the observable of mean intensity for both deep and shallow water environments. This talk will address the issues of: the accuracy of the approximations, relative contributions from coupling and adiabatic effects, scaling with range and frequency, and the functional form of the coherence with regards to lag.
Observations of Philippine Sea sound-speed perturbations, and the contributions from internal waves and tides, and spicy thermohaline structure
Authors: Colosi John , Dushaw Brian , Van Uffelen Lora , Dzieciuch Matt , Cornuelle Bruce , Worcester Peter
Published: October 2011

In the PhilSea09 pilot study two moorings equipped with temperature (T), conductivity (C), and pressure sensors, along with upper ocean ADCP, monitored ocean variability for a month in the Spring. The measurements reveal an energetic and nonlinear mixed diurnal-semidiurnal internal tide, a diffuse Garrett-Munk (GM) type internal wave field at or above the reference GM energy level, and a strong eddy field. One mooring, which was equipped with pumped sensors for enhanced salinity (S) resolution, was able to accurately quantify T and S variability along isopycnals (spice). The spice contribution to sound-speed fluctuation is observed to be strong near the mixed layer but significantly weaker than the other contributions in the main thermocline. Frequency spectra as well as vertical covariance functions will be presented to quantify the temporal and vertical spatial scales of the observed fluctuations.
Ambient noise bathymetric domains
Authors: Ross Donald , McKenna Megan F. , Wiggins Sean M. , Hildbrand John A.
Published: October 2011

For the purposes of describing and understanding ambient sea noise for frequencies below about 300 Hz, most of the world's seas can be classified as belonging to one of three bathymetric domains. These domains are distinguished by their proximity to shipping lanes and by the degree to which they are exposed to noises originating at long distances. The three domains display different short-term characteristics as well as different historical patterns. In this paper, the three domains are described and typical ambient noise characteristics for each are shown, including changes which are attributable to increased ocean commerce.
Numerical analysis of sound radiation underwater from a fully submerged pile
Authors: Shahab Shima , Woolfe Katherine F. , Hastings Mardi C.
Published: October 2011

The study of acoustic radiation from pile driving is essential because the impact between the hammer and pile causes extremely high underwater sound pressure levels that are potentially harmful to the marine environment. When the hammer strikes a cylindrical steel pile, movement of the pile wall in circumferential, longitudinal, and radial directions can excite many modes of vibration. The radial expansions of the pile that propagate along the pile after impact create sound waves in the surrounding water. A finite-difference time-domain (FDTD) formulation is presented to analyze the sound produced from a fully submerged pile with simply supported ends. The pile considered is a cylindrical shell of finite length, bounded by sediment at the bottom end, and surrounded by and filled with water. Three coupled partial differential equations govern the vibration of the shell, and the effects of acoustic media including water and sediment are added in the radial direction. Results of a correlation between the radiated sound field predicted by the FDTD model and acoustic data from a scaled physical model of a fully submerged pile hit with an impact hammer are presented. [Work supported by the Oregon Department of Transportation and Georgia Institute of Technology.]
Hyperoodon echo-morphology: Biosonar anatomy in the northern bottlenose whale
Authors: Cranford Ted W. , Rasmussen Marianne H. , Potter Charles W. , Krysl Petr
Published: October 2011

The northern bottlenose whale (Hyperoodon ampullatus) is one of the largest toothed whales, marked by an outsized bulbous forehead. Like other odontocetes, the head contains a sophisticated biosonar system. The in situ anatomic geometry of the biosonar components is normally inaccessible by the large size of these animals. We acquired a 400 kg head from a 6.18 m female Icelandic bottlenose whale. The head was encased in a special sarcophagus. An industrial CT scanner generated more than 700 scans at 2 mm thick, from which we reconstructed the detailed anatomy of the head. The acoustic fats are ensheathed in higher density (acoustically reflective) tissues that act to channel sounds into and out of the head. Lipid channels begin at both sets of phonic lips, coalesce into a single S-shaped channel that eventually passes between two large maxillary crests, and then forms a horn shaped melon that projects sound into the environment. Sounds are apparently received over the jaws and throat and travel back to the bony ear complexes through lipid pathways. These lipid channels bifurcate and insert onto the ear complex where the bone is thin. The finite element simulations for biosonar sound transmission and will be reported.
Dolphins (Tursiops truncatus) use multiple auditory mechanisms for detecting tonal signals in natural and anthropogenic noise
Authors: Branstetter Brian K. , Trickey Jennifer S. , Bakhtiari Kimberly L. , Finneran James J.
Published: October 2011

The dolphin's ability to detect a 10 kHz tone masked by a variety of noise types was measured using a standard band-widening paradigm. Maskers included natural noise (rain, snapping shrimp, and ice squeaks), anthropogenic noise (pile saw and boat propeller cavitation) and statistical noise (Gaussian and comodulated noise). For most noise types, detection thresholds increased as noise bandwidth increased up to 1 kHz (the dolphin's critical bandwidth at 10 kHz). Masking patterns for narrow-band maskers were similar regardless of the masker type. However, for noise bandwidths greater than 1 kHz, masking patterns diverged by as much as 23 dB depending on the noise type. The power spectrum model provided reasonable predictions for Gaussian, rain, pile saw, and boat noise masking patterns. Additional experiments suggested that mechanisms related to temporal envelope processing (across-channel envelope comparison and within-valley listening) determined masking patterns for snapping shrimp and comodulated noise. Thresholds in ice squeak noise, which proved to be the most effective masker, were related to the dolphin's inability to discriminate the signal from the background noise rather than inability to detect the signal. These results suggest that the dolphin auditory system uses multiple mechanisms for signal detection in complex noise [Work supported by the ONR.]
Auditory effects of multiple underwater impulses on bottlenose dolphins (Tursiops truncatus)
Authors: Finneran James J. , Trickey Jennifer S. , Branstetter Brian K. , Schlundt Carolyn E. , Jenkins Keith
Published: October 2011

It is becoming increasingly clear that noise may adversely affect the hearing and behavior of many marine mammals, including dolphins and whales. One of the possible consequences of noise exposure is a temporary loss of hearing sensitivity, called a temporary threshold shift (TTS). Previous studies of TTS in marine mammals have used only steady-state and single impulsive sounds; however, many naval, seismic survey, and construction activities generate multiple underwater impulsive sounds. To investigate the auditory effects of multiple underwater impulses, auditory thresholds were measured in bottlenose dolphins before and after exposure to a series of impulses produced by a seismic airgun. Hearing thresholds were compared to determine the amount of TTS as a function of exposure level and the number of impulses. Thresholds were measured by using both psychophysical and auditory evoked potential methods. Preliminary results reveal no measurable TTS after exposure to 10 impulses, with a total cumulative sound exposure level of approximately 195 dB re 1 μPa2 s. [Work supported by the EP Sound and Marine Life Joint Industry Programme.]
Time-variant biomimetic beamforming baffle prototypes augmented with local shape features
Authors: Pannala Mittu , Reddy Ojili Praveen Kumar , Meymand Sajjad Z. , Müller Rolf
Published: October 2011

Horseshoe bats are known to exhibit non-rigid pinna deformations as part of their biosonar behaviors. During these deformation cycles, the pinnae of the animals alternate between upright and bent shape configurations that differ in their overall geometry as well as in the shapes and relative positions of local shape features. Artificial baffle prototypes have been designed to emulate these deforming bat pinnae. The prototype shapes were designed by augmenting an obliquely truncated cone with biomimetic local shape features. The prototype was implemented using elastic (synthetic rubber) materials. The deformation of the structure was accomplished through a simple actuation mechanism that was inserted on the back side of the artificial pinna. Features of the horseshoe bat pinna that have been evaluated for this study include a prominent vertical ridge that runs along the entire inner pinna surface, the antitragus along with the lateral incisions that separate it from the back portion of the pinna, and a pinna-edge incision near the tip of the pinna. An experimental analysis of deforming prototypes has demonstrated that such biomimetic local shape features affect the beampattern of the static artificial pinna shape as well as the time-varying properties of the deforming prototype.