bluuebunny/crossref_metadata_2025 huggingface dataset:
Source location using a distributed array of aerostats
Authors: Di Xiao , Shi Tau , Gilbert Kenneth E.
Published: October 2013

An elevated microphone on an aerostat generally can detect a source at a considerably longer range than a microphone on the ground. However, because of the balloon motion, an array of microphones on a single aerostat generally cannot determine a bearing to a source as accurately as a ground-based array. To obtain both long detection ranges and accurate bearings, tests have been done using single microphones on aerostats having a horizontal separation of approximately 100 m. With a long horizontal baseline between the microphones, the bearing estimate is much less sensitive to the balloon motion. Thus, the balloon motion does not have to be precisely monitored. Results from preliminary tests will be presented and discussed. [Research supported by the U. S. Army TACOM-ARDEC at Picatinny Arsenal, New Jersey.]
The degree family tree of Brian E. Anderson
Authors: Anderson Brian E.
Published: October 2013

The degree family tree of Brian E. Anderson will be presented. The poster will display evidence of the strong connection between the Graduate Program in Acoustics at The Pennsylvania State University and the Acoustics Research Group of the Department of Physics and Astronomy at Brigham Young University. Currently Brian represents a branch with no fruit, but Brian hopes to someday bear much fruit (advise graduate students as a faculty member).
Harvard academic tree leading back to Helmholtz
Authors: Blackstock David T.
Published: October 2013

From 1946 to 1971, 30 Harvard Ph.D. degrees were earned in F. V. (Ted) Hunt’s Acoustics Research Laboratory. Although Hunt was on my committee, and I’ll always consider myself one of ‘‘Hunt’s boys,’’ William P. Raney was my Ph.D. (Harvard, 1960) supervisor. My direct ancestral line thus begins with Raney, who did his doctoral research at Brown University (Ph.D. 1955) under Peter J. Westervelt. The lineage going further down the tree is as follows: Westervelt (MIT, 1951), Richard H. Bolt (UCLA, 1939), Vern O. Knudsen (University of Chicago, 1922), Robert A. Millikan (Columbia, 1895), Michael I. Pupin (Berlin, 1887), Hermann von Helmholtz (Berlin, medicine, 1842). Now go up the tree. I had two Ph.D. students at the University of Rochester, Donald B. Cruikshank (1968) and James C. Lockwood (1971). My first Ph.D. graduate from the University of Texas at Austin was F. Michael Pestorius (1973); eight younger siblings followed. A bonus was being stepfather for Mark F. Hamilton (Penn State, 1983) when his Penn State supervisor, Frank Fenlon, died in 1981. I was also blessed with 22 master’s students at Texas.
Geneology of Phil Marston
Authors: Matula Thomas , Marston Philip
Published: October 2013

This poster will highlight the geneology of Philip Marston. The poster will follow the geneological progression from Phil’s past advisors to his students.
Neural representation of pitch in auditory cortex
Authors: Wang Xiaoqin
Published: October 2013

Pitch perception is crucial for vocal communication, music perception, and auditory object processing in a complex acoustic environment. The neural representation of pitch in the cerebral cortex has long been an outstanding question in auditory neuroscience. Both animal and human studies have implicated the role of the cerebral cortex in underlying pitch perception. Recent findings indicate that there is a specialized region in the auditory cortex of primates that is involved in the representation of pitch. This presentation will review key studies in the identification of a pitch processing center in primate auditory cortex and discuss issues concerning the neural substrate of pitch perception. [Research supported by NIH Grants DC003180 and DC005808.]
Individual differences in the production and perception of the voicing contrast by native and non-native speakers of English
Authors: Smith Bruce L. , Hayes-Harb Rachel
Published: October 2013

Investigations of acoustic characteristics of speech production and their perceptual correlates often determine that various common patterns are observed among groups of talkers/listeners. It is also sometimes reported that a certain amount of noise occurred in the data, i.e., that not all subjects fit general patterns that were observed. While individuals who do not demonstrate typical patterns are often viewed as outliers, subjects who represent exceptions also provide important information. The present study reports findings obtained from 15 native speakers of English and 15 non-native (native Mandarin) speakers of English who were recorded producing several final-position voiced/voiceless CVC word pairs and who also made voicing judgments about voiced/voiceless cognates produced by other native English and native Mandarin speakers. All native subjects in the present study produced multiple acoustic cues in making voicing distinctions (e.g., vowel duration, final stop closure duration, voicing during final stop occlusion, release burst); however, not all subjects used all these acoustic cues or the same combinations of cues in their voicing contrasts. Only about half the native Mandarin speakers used multiple acoustic cues in attempting to produce a voicing contrast. Various group trends, as well as subgroup variations, in production and perception will be discussed.
Speeded discrimination of American vowels by experienced Japanese late L2 learners
Authors: Ito Kikuyo , Law Franzo F. , Sperbeck Mieko N. , Berkowitz Shari , Gilichinskaya Yana D. , Monteleone Marisa , Strange Winifred
Published: October 2013

This study is part of a larger project to examine online perception of American (AE) vowels by non-native listeners from languages with small vowel inventories. A speeded ABX categorial discrimination task with disyllables /Vp■/ was used to examine Japanese L2 learners relative difficulties differentiating 8 AE vowels contrasted in 13 pairs: 6 adjacent height contrasts among front [i:/■, ■/[g\/], [g\/]/æ:] and back [u:/■, ■/■, ■/■:] vowels and 3 front/back pairs [■/■, [g\/]/■, æ:/■:]; 4 nonadjacent height pairs [i:/[g\/], ■/æ:, u:/■, ■/■:] served as controls. Reaction times for native AE listeners did not vary across the 13 contrasts, despite differences in psychoacoustic distance between vowel pairs, reflecting automatic processing of native contrasts. However, for Japanese listeners, performance on contrasts among psychoacoustically more similar [[g\/], æ:, ■:, ■] yielded the slowest latencies, especially for front/back pairs that did not differ in duration. Height contrasts between high/mid-high vowels (height+duration) and mid-high/mid-low vowels (height only) were discriminated somewhat faster, although not as fast as control contrasts. The latter were discriminated as rapidly as native Japanese height and length contrasts. Results suggest that response latencies are a sensitive measure of differences in automaticity of online processing of native and non-native contrasts.
Frequency variability of modal attenuation coefficients
Authors: Saintval Wendy , Siegmann William L. , Carey William M. , Pierce Allan D.
Published: October 2013

The intrinsic sediment attenuation in adiabatic waveguides affects transmission loss through the modal attenuation coefficients (MACs). For sand-silt bottoms, the non-linear frequency dependence of attenuation in the upper sediment layer significantly affects the frequency variation of the MACs. This variation is shown to depend strongly on the water, and weakly on the upper sediment layer, sound-speed profiles. The MACs are calculated for a layered environmental model that permits good comparisons with values derived from experimental data in the Gulf of Mexico [Ferris, JASA, 82 (1972)]. The comparisons illustrate the dependence on measured water profiles. The rate of increase of transmission loss with range is conveniently measured by an effective attenuation coefficient. The relationship between this quantity and the MACs is known when one propagating mode dominates [Evans and Carey, JOE, 23 (1998)]. We describe the interesting connection for downward refracting profiles at mid-frequencies with multiple propagating modes. [Work partially supported by ONR.]
A robust method for approximating acoustic field uncertainty in underwater sound channels
Authors: James Kevin R. , Dowling David R.
Published: October 2013

Environmental uncertainty in underwater sound channels is often the dominant source of error in acoustic field predictions. Standard Monte Carlo techniques to quantify the effect of this uncertainty are prohibitively time consuming for many applications. This presentation evaluates an alternative method for approximating the relationship between uncertain environmental parameters and uncertainty in the predicted field. Using FFT techniques, the effect of small changes in uncertain parameters is correlated to small spatial displacements of the original field. By appropriately extrapolating this relationship between uncertain parameters and the resulting field, an approximate probability distribution can be calculated for the field amplitude. A variety of test cases are shown to evaluate the accuracy of this method in underwater sound channels. Several uncertain parameters are addressed, including bottom characteristics, water column depth, source characteristics, and water column properties. Application of this method to current field prediction routines is discussed. Results are compared to exact solutions, Monte Carlo simulations, and simple linear approximations. In particular, for the sound channels studied, when environmental uncertainties remain within meaningful limits, approximate field amplitude distributions generally exhibit means and standard deviations within 10% of those calculated from the exact field amplitude distribution. [Work sponsored by the Office of Naval Research, Code 321OA.]
Comparison of two and three spatial dimensional solutions of the wave equation at ocean-basin scales in the presence of internal waves
Authors: Spiesberger John
Published: October 2013

Numerical solutions are given for a parabolic approximation to the acoustic wave equation at 75 Hz in two and three spatial dimensions to determine if azimuthal coupling of the field significantly affects horizontal coherence. Coupling is a small effect at 4000 km in the presence of internal gravity waves. This implies that accurate solutions are possible using computations from uncoupled vertical slices through the field. The shape of horizontal coherence is inconsistent with shapes given by two theories. Estimates of horizontal coherence at 4000 km and 25, 50, and 75 Hz are 10, 2, and 1 km respectively. [Work supported by the ONR.]
Strategies for seismic signal communication in spiders
Authors: Elias Damian O. , Mason Andrew C. , Hebets Eileen A.
Published: October 2013

Communication is often hypothesized to be optimally designed for its specific signaling environment. While empirical studies have demonstrated this in several systems, the effect of high channel availability and heterogeneity has not been explored. Seismic (vibratory) communication presents a potential sender with a variety of potentially distinct signaling channels. Using examples from two types of spiders (Salticidae and Lycosidae), it is demonstrated that small animals use one of two strategies. Animals can be either: (1) specialized to the properties of a particular subset of signaling channels (narrow band signals) or (2) general to all signaling channels (broadband signals). Tradeoffs are discussed as well as the mate choice patterns associated with these different strategies. [Funding was provided by the National Science Foundation, the Natural Sciences and Engineering Council, and a Sigma Xi Society Grant-in-Aid.]
A non spectrum-based visual display tool
Authors: Nordquist Peter R. , Ayers R. Dean , Kato Daisuke , Nakao Lewis
Published: October 2013

A software program was developed to help musicians learn to tune just intonation intervals. A reference tone is played and Lissajous-like figures present a visual representation of the interval the musician’s sound makes with the reference tone. This approach is interesting, because the musician receives coordinated aural and visual feedback in real time, and this visual representation is produced without the overhead of doing a Fourier transform. Experiments that modify the figures to produce a usable representation of timbral differences, also using a non spectrum-based algorithm, are planned. [Work supported by the Veneklasen Foundation.]
The charge ordering transition as probed by ultrasound
Authors: Mandrus David , Angst Manuel , Luan Yanbing , Keppens Veerle
Published: October 2013

Charge ordering (CO) phenomena are found in many correlated electron systems but in general are poorly understood. A classical example of CO is found in magnetite, Fe3O4, which undergoes a CO transition (the so-called Verwey transition) at 120 K. Magnetite is a poor model system for studying CO; however, despite nearly 70 years of study, there is still no generally accepted description of the transition. In recent years several new materials that display CO transitions have been discovered, including Fe2OBO3 and LuFe2O4. These new materials are proving to be far better model systems for studying CO than magnetite. In this talk the Landau theory of CO transitions will be reviewed, and the behavior of the elastic response of LuFe2O4 will be discussed in this context. [Work at ORNL supported by DOE BES Division of Materials Science and Engineering. Work at UT supported by NSF DMR-0506292.]
Extracting the local Green’s function from ocean noise on a horizontal array
Authors: Fried Stephanie E. , Sabra Karim G. , Kuperman William A.
Published: October 2013

Time delays, associated with different ray paths between the elements of a bottom hydrophone array, can be extracted using ambient noise cross-correlations [Sabra et al., J. Acoust. Soc. Am. 114, 2462 (2003)]. This is confirmed using long time noise recordings that were collected in May 1995 near the S. California coast at an average depth of 21 m. The noise is mainly biological in the frequency range of 250–700 Hz [D. Spain et al., J. Acoust. Soc. Am. 99, 2453 (1996)]. The cross-correlations of noise from a horizontal array can be used to extract the local Green’s function from the ocean ambient noise. [Research supported by ONR.]
Environmental effects on passive fathometry and bottom characterization
Authors: Means Steven L. , Siderius Martin
Published: October 2013

Recently, Siderius, Harrison, and Porter developed a method, based on the Fourier synthesis of the cross-spectral density from nearby positions, to exploit the oceans’ coherent ambient noise field due to breaking waves to make measurements of the bottom and subbottom properties. During 2006 breaking wave noise measurements were made in the shallow waters (25 m) approximately 75 km off the coast of Savannah, GA on a 32-phone, three nested-aperture, vertical hydrophone array that was deployed 100 m from a Navy tower that stands 50 m above the water surface. The Skidaway Institute of Oceanography operates a suite of instruments for measurements of both atmospheric and oceanic conditions at the tower. Data were collected in a variety of environmental conditions, with wind speeds ranging from 5–21 m/s and wave heights of 1–3.4 m. The data is analyzed to quantify the performance of the passive fathometer methods as a function of the wind speeds, wave conditions, and averaging times. The results will be compared with ground-truth measurements made at the tower site prior to its construction. [Work supported by ONR base funding at NRL.]
Evaluation of an acoustical-optical platform for measuring species specific abundance in a weir trap
Authors: Miksis-Olds Jennifer L.
Published: October 2013

Data recorded by a bottom mounted survey platform deployed within the opening of a fishing weir were used to calculate absolute abundance estimates for comparison to the weir catch. Species specific abundance estimates were calculated from a combination of sonar and video information recorded by the acoustical-optical platform (AOP). Individual targets were detected in the sonar images using an echo counting technique. Video images were used to provide species identification of acoustic targets within an approximate 10 m range. The number and identification of acoustic targets detected during each deployment was positively correlated with the total catch weights and dominant species in each deployment. The algorithm used to calculate AOP abundance estimates tended to underestimate abundance when more than 50 individuals of the same species were caught and overestimate abundance when less than 50 individuals were caught. Target strength, bearing, and range distributions for individual targets are presented in addition to the species specific percent difference between the AOP estimates and absolute abundances of the weir catch. The agreement between the species specific AOP estimates and absolute abundances of each species indicate that the AOP has the potential to provide data for accurate estimates of multispecies abundance. [Work supported by NOAA.]
Classification of wolf call types using remote sensor technology
Authors: Curless Deborah , Roch Marie A. , Madhusudhana Shyam , Soldevilla Melissa S. , Hildebrand John A. , Baker Elizabeth , Moriarty Dan , Miller Kim
Published: October 2013

A system is presented for the near-real-time classification of calls from captive Alaskan (Canis lupus occidentalis) and Mexican (Canis lupus baileyi) wolves as well as other ambient sounds such as bird calls and anthropomorphic noise. Signals are detected on a Viper network node at The California Wolf Center using a signal-to-noise ratio based call activity detector. These calls are transmitted over a regional high-speed wireless network (HPWREN) to a remote processing facility located 50 miles from the collection site. Cepstral feature vectors are extracted from candidate calls at the remote facility and are classified using a hidden Markov model pattern recognition system trained with manually labeled data representing the wolf ethogram and other common noises in the soundscape. In an offline evaluation with known segmented data, the system achieves an 84% accuracy. [This work is supported by HPWREN, NSF Grant No. 0426879.]
A proposed technique for source localization using an autonomous underwater vehicle
Authors: Cockrell Kevin , Schmidt Henrik
Published: October 2013

It has been of recent interest to use autonomous underwater vehicles (AUVs) with towed arrays for source localization in ocean acoustic waveguides with uncertain environmental parameters. However, AUVs cannot implement source localization techniques designed to be robust against environmental mismatch because such techniques require more computational power than is typically available on an AUV. To address this issue, a technique is proposed that increases robustness to environmental mismatch by utilizing computational resources available before the measurement of the acoustic field is made (i.e., computational resources on the ship from which the AUV is launched). This is done by using a numerical ocean acoustic model to analyze how uncertainty in environmental parameters affects the acoustic pressure levels at the hydrophones of the array. The results of this analysis can then be stored on the AUV’s computer and used by the source localization algorithm. The relationship between the proposed technique and matched mode processing is discussed.
Harmonic motion detection in a vibrating scattering medium
Authors: Urban Matthew W. , Greenleaf James F.
Published: October 2013

Dynamic ultrasound radiation force can induce local tissue vibration. To understand the tissue response, we developed a method to ultrasonically measure the induced motion. We present a model for motion detection in a vibrating scattering medium. We developed a harmonic pulsed excitation method using tonebursts repeated at frequency fr. This excitation method creates a multifrequency force with components at harmonics of fr. We use pulse-echo ultrasound and narrowband Kalman filtering to perform multifrequency motion detection. In an experiment, a 3.0 MHz air-backed transducer was used to create the radiation force, and with the same transducer performed pulse-echo motion detection at 9.0 MHz. Bovine muscle was used for radiation force excitation and motion detection. We present simulation results for a parameterized model of motion detection in a scattering medium. We show experimental measurements of vibration displacement and phase for motion with amplitude of 0.1–10 μm. Our simulation model provides a platform to optimize detection of small harmonic motion in a scattering medium. Multifrequency harmonic pulsed excitation and detection methods are presented that induce and measure very small amplitude harmonic motion.
Validating and expanding the theoretical frameworks that relate ultrasonic backscatter to scatterer properties
Authors: Dasgupta Shreedevi , Feleppa Ernest , Mamou Jonathan , Rondeau Mark , Lloyd Harriet
Published: October 2013

Backscattered echo signals are related to scatterer properties in theoretical frameworks published independently by Lizzi and Insana. These frameworks are based on assumptions that may not consistently apply to tissue scatterers. Our study aims to confirm and expand the theory to include scattering under a variety of scatterer conditions. A 35-MHz transducer was used to scan suspended 12-μm-diam uveal melanoma cells. Using Fourier methods, spectral parameters were computed from ultrasonic echo data acquired from the suspension. Normalization was implemented in two ways. First, a glass-plate calibration spectrum was subtracted from the experimental data. Second, the spectrum acquired from suspended 20-μm beads was compared to the spectrum predicted by Faran’s theory. The difference between expected and experimental spectra was attributed to system effects. Cell acoustic impedance was estimated from cell-pellet density and propagation velocity. Theoretical spectral values were computed from cell size, concentration, and acoustic impedance using the Lizzi framework. The cell pellet propagation velocity was 1550 m/s, and the acoustic impedance was 3587 kg/m-s. The normalized, experimental spectral parameters agreed closely with the theoretical predictions. Future work will include different scatterer sizes and geometries and a comparison of results obtained using the Lizzi and Insana frameworks.
Directivity and spectral characteristics of aircraft noise during landing operations
Authors: Dunkin Bradley M. , Atchley Anthony A. , Hodgdon Kathleen K.
Published: October 2013

Recordings of aircraft landing operations have been analyzed to obtain directivity and spectral characteristics of the noise emitted during these operations. The recordings were made with a widely spaced microphone array positioned near and parallel to the 19R runway at Washington-Dulles International Airport. In addition, the landings were recorded with a video camera to obtain positional data of the aircraft. Given an aircraft’s position and velocity along the runway, the signal at each microphone is corrected for retarded time, spherical spreading, and Doppler shift. The corrected signals are combined to establish a directivity pattern, and third-octave analysis is performed to obtain spectral characteristics. The results of this analysis are intended to be used as input to airport noise modeling software such as the Integrated Noise Model (INM), which currently models landing noise using forward-thrust input data. The current analysis should provide more realistic directivity and spectra for the reverse-thrust condition. [Work supported by the Federal Aviation Administration and the Applied Research Laboratory Exploratory and Foundational Research Program.]
Measurement of vessel underwater noise, standard development status
Authors: Bahtiarian Michael
Published: October 2013

The development of an entirely new commercial standard for underwater noise measurement of ships started in early 2007. Currently, no voluntary consensus standard exists for performing underwater noise measurements of ships. For many years, the field of underwater noise from ships has been the exclusive specialty of the Navy. However, non-Navy vessels are looking to be just as quiet so that they can perform better science. Green Ships are being conceived in order to have less emission into the ocean. The goal of the project is to develop an American National Standard for the measurement of underwater noise levels of ships using commercial technology. One aim is that the standard would be applicable to any open ocean site in the world and not require traveling to special acoustic test range. The committee’s scope of work will include neither regulatory actions nor the development of any underwater noise level limits. This presentation will be an update of the committee work to date. A mission statement of the committee and discussion of measurement grades is to be presented. The presentation shall also serve as outreach to the acoustical community. As such, the author hopes to provide time for questions and feedback.
Modelling sound preference
Authors: Yu Lei , Kang Jiang
Published: October 2013

More and more attention is being paid to soundscape quality by today’s acoustic researchers and environmental designers. It is important that, in addition to noise annoyance, sound preference is another main component to determine soundscape quality, especially in urban open public spaces. Previous studies showed that subject evaluation of sound preference in urban open public spaces varied according to physical, psychological, and social variables [W. Yang and J. Kang, J. Urban Des. 10, 69–88 (2005)]. Prediction models using artificial neural network (ANN) techniques for sound preference have been developed, as presented in this paper. Suitable input variables for ANN models have been derived from SPSS analyses based on data collected from large scale field studies and laboratory experiments [L. Yu and J. Kang, J. Acoust. Soc. Am. 120, 3238 (2006)]. These input variables include psychoacoustic indices such as loudness, sharpness and roughness, subject’s social/demographic factors and their long-term sound experience, while the sound preference, described as acoustic comfort or pleasantness, is set as the output. Through the process of training and testing the models, good convergences have been achieved, which means that the prediction of sound preference evaluation is possible at the design stage.
Case study of soundscape assessment and design methods
Authors: Siebein Gary W. , Kwon Youngmin , Smitthakorn Pattra , Gold Martin A.
Published: October 2013

A case study of the soundscape assessment and design process for an urban design intervention in a medium-sized city was conducted as an investigation of acoustical assessment and design methods. A series of long-term acoustical measurements of average sound levels in the community as well as more detailed measurements and aural recordings of specific acoustic events that comprised the ambient sounds were mapped for the community. Measurements included overall A-weighted and octave band sound levels and calibrated audio recordings. Sound walks were conducted at various times of day to understand the dynamics of the acoustical environment and to identify issues. Focus group discussions among stakeholders and team members developed the long-term plans for the community and determined appropriate architectural and acoustical design criteria for the project. The acoustical data were used as the basis for determining design strategies for the urban interventions including reducing, buffering, and mitigating undesirable existing sounds, preserving and enhancing desirable existing sounds, and designing new soundscape elements to enhance the comprehensive plan for the community. The results of the study included an assessment of the acoustical analysis methods and soundscape design strategies for the project.
Evaluation of field impact sound pressure levels as a function of tapping machine location
Authors: LoVerde John J. , Dong D. Wayland
Published: October 2013

Field impact sound insulation in the United States is typically quantified in terms of Field Impact Insulation Class, which is defined in ASTM E1007. This standard requires averaging the receiving room impact sound pressure levels (ISPL) generated by the tapping machine in four defined positions. To our knowledge the variation in ISPL with different tapping machine positions has not been quantified for field measurements. Hundreds of recent field tests are compiled for a statistically significant analysis of this variation, covering all common floor/ceiling assembly construction types and many different flooring and resilient materials. The effects of reducing the number of tapping machine positions in the ASTM standard on the accuracy and precision of the measurement are evaluated.
Demonstration of properties of human hearing using a cochlear analogue
Authors: Tomlinson Seth S. , Anderson Ryan , Gee Kent L. , Sommerfeldt Scott D.
Published: October 2013

A device has been constructed that demonstrates the spectral decomposition of waves according to spatial location, analogous to the function of the basilar membrane of the mammalian cochlea. The design is based on a previous device constructed by Keolian [J. Acoust. Soc. Am. 101, 1199–1201 (1997)]. We have modified Keolian’s design to incorporate variable mass as well as stiffness and an electronically driven shaker, which allows the device to be driven with complex waveforms. In addition to showing spectral decomposition, the model can be used to demonstrate beating, masking, and other phenomena that occur on the basilar membrane. A demonstration of the device will be given.
The propagation of sound on Titan using the direct simulation Monte Carlo
Authors: Hanford Amanda D. , Long Lyle N. , Sparrow Victor W.
Published: October 2013

With the recent success of the Huygens lander on Titan, a moon of Saturn, there has been renewed interest in exploring the acoustic environment of the only moon in the solar system with a significant atmosphere. The direct simulation Monte Carlo (DSMC) method is used here for modeling sound propagation in the Titan atmosphere. DSMC is a particle method that describes gas dynamics through direct physical modeling of particle motions and collisions. DSMC is based on the kinetic theory of gas dynamics, where representative particles are followed as they move and collide with other particles. The validity of DSMC for the entire range of Knudsen numbers (Kn), where Kn is defined as the mean free path divided by the wavelength, allows for the exploration of sound propagation in the Titan atmosphere for all values of Kn. DSMC results for the absorption of sound have shown that sound absorption depends heavily on Kn and deviates significantly from the continuum classical assumption for large Kn. This talk presents the successful application of the DSMC method to acoustic waves in the Titan atmosphere for a large range of Kn. [Work supported by NASA.]
Age-related declines in the precedence effect and the detection of the dynamic change in interaural correlation
Authors: Huang Juan , Huang Ying , Wu Xihong , Li Liang
Published: October 2013

Elderly adults experience greater difficulties with sound localization tasks involving the precedence effect (PE) than young adults (Cranford et al., 1990). In this study, the echo threshold of the PE and the threshold for detecting the dynamic change in interaural correlation were investigated in 12 young adults and 8 elderly adults with clinically normal hearing. For studying the threshold of detecting the dynamic change in interaural correlation, participants were presented with either binaurally-uncorrelated or binaurally-anti-phase noise fragments, which were inserted in the middle of two interaurally identical (correlated) broadband noise markers (duration=900 ms) delivered by headphones. Either the duration of the noise fragment or the ITD of the noise markers was manipulated. Compared to young participants, elderly participants had both higher echo thresholds and higher fragment-duration thresholds at various ITDs. The echo threshold was significantly correlated with the fragment-duration threshold in elderly participants but not in young participants. These results suggest that there are age-related declines in processing interaural signals, which may account for elderly adults’ poor performance in discriminating and localizing sound sources in noisy, reverberant environments.
Intervention for restricted dynamic range and reduced sound tolerance
Authors: Hawley Monica , Sherlock LaGuinn , Gold Susan , Segar Allyson , Gmitter Christine , Cannavo Justine , Formby Craig
Published: October 2013

Hyperacusis is the intolerance to sound levels that normally are judged acceptable to others. The presence of hyperacusis (diagnosed or undiagnosed) can be an important reason that some persons reject their hearing aids. Tinnitus retraining therapy (TRT), originally proposed for the treatment of persons with debilitating tinnitus, offers the significant secondary benefit of increased loudness discomfort levels (LDLs) in many persons. TRT involves both counseling and the daily exposure to soft sound from bilateral noise generator devices (NGs). We implemented a randomized, double-blind, placebo-controlled clinical trial to assess the efficacy of TRT as an intervention for reduced sound tolerance in hearing-aid eligible persons with hyperacusis and/or restricted dynamic ranges. Subjects were assigned to one of four treatment groups: (1) full treatment, both counseling and NGs, (2) counseling with placebo NGs, (3) NGs without counseling, and (4) placebo NGs without counseling. They were evaluated at least monthly, typically for 5 months or more, on a variety of audiometric tests, including LDLs, the contour test for loudness for tones and speech, word recognition measured at each session’s comfortable and loud levels, and on electrophysiological measures. We will present interim results and selected examples of positive treatment effects. [Work supported by NIH R01 DC04678.]
The ‘‘noise’’ of tinnitus and the vagaries of perception
Authors: Gildston Phyllis
Published: October 2013

Multiple suspected etiologies for tinnitus encourage the development of multiple rehabilitation approaches. Loud noises, drugs, hearing loss, ear infections, tumors, Meniere’s, head injuries, and TMJ have been cited, among many others, as potential causes. Even high impact exercise and stress are suggested culprits. A full understanding of the phenomenon is still, however, a long way off. Once all known remediable sources have been attended to, why should a remaining noise in the ear (measured as perceived at a particular loudness level) cause such severe psychological consternation in so many sufferers while others barely notice it exists? What mechanisms may be involved in the alteration of perception following successful rehabilitative procedures such as masking, hearing amplification, cognitive behavioral perceptual retraining, or hypnotherapy? This presentation will focus on changes induced by hypnosis which typically lead to a significant decrease in the perceived loudness level of the tinnitus and a significant increase in psychological well being. What is known of the science and art of hypnosis will be explored in an attempt to explain this often achieved metamorphosis in perception. Video clips from hypnotherapeutic sessions with correlated perceptual aftermaths will complement a review of scientifically known facts about the disorder.
Fluid dynamics measurements during phonation
Authors: Alipour Fariborz
Published: October 2013

Fluid dynamic properties of air within the larynx changes so rapidly during phonation that its measurement could be a challenge for voice research. These measurements included time varying glottal pressure and air particle velocity in narrow passages that pose many technical difficulties. In this paper, to elucidate these challenges, measurement of dynamic pressure acting on the vocal folds in a canine hemilarynx model has been initially examined. Then static and dynamic volume flow measurements and, finally, the particle velocity measurements with hot-wire anemometry within the glottal jet have been discussed. Canine excised larynges as well as canine hemilarynges were used as phonation models. For dynamic pressure measurements, miniature pressure transducers were embedded in a Plexiglas plate that replaced one vocal fold and recorded the oscillation pressure. All mounted laryngeal models were subjected to increasing pressure-flow sweeps at various adduction levels and the measured data was processed for dynamic pressure and velocity profiles. Results indicated that pressure within the glottis vary both vertically and longitudinally during each vibratory cycle. The pressure signals close to the superior edge showed large negative values due to the motion of the vocal folds. [Work supported by NIDCD Grant No. DC03566.]
Experimental investigation of the influence of a posterior commissural gap on the glottal flow resistance of a larynx model
Authors: Mongeau Luc , Park Jong Beom
Published: October 2013

The influence of a posterior commissural gap (or chink) on the pulsated glottal flow was investigated using a driven physical model having a converging coronal-planar profile. Instantaneous orifice discharge coefficients of the model were obtained from the time-varying orifice area and the velocity distribution of the pulsated glottal jet measured in the axial plane using a single hot-wire probe. Sound pressures were also measured to characterize the acoustical influence of the minimum flow through the posterior chink on the radiated sound. A cyclic hysteresis of the orifice discharge coefficients was observed, which indicates a pressure head increase and a net energy transfer from the air flow onto the orifice wall. A comparison between the cases with and without the posterior chink showed that the presence of a minimal flow increased the radiated sound pressure amplitude in the frequency range in which human hearing is most sensitive.
A controlled-strain rheometer for the measurements of vocal fold viscoelasticity at phonatory frequencies
Authors: Chan Roger W. , Rodriguez Maritza
Published: October 2013

Glottal fluid-structure interactions are critically dictated by the viscoelastic properties of the vocal fold. Viscoelastic shear response of the vocal fold lamina propria has been reported previously, but with torsional rheometers data have only been obtained at low audio frequencies (up to about 80 Hz), necessitating data extrapolation to predict tissue properties in the typical phonatory frequency range. In order to characterize the viscoelastic behavior of vocal fold tissues at higher frequencies, a controlled-strain, linear simple shear rheometer was built based on the linear-motor design of the EnduraTEC ELF 3200 system. A tissue specimen was subjected to simple shear between two rigid rectangular acrylic plates, with the displacement measured by a linear variable displacement transducer (LVDT), and the shear force response detected by a piezoelectric quartz transducer. The frequency responses of the system components were assessed by accelerometers, and the complex shear modulus (G*) of a standard ANSI 2.21 polyurethane material and that of vocal fold specimens were measured. Results showed that the rheometer can provide valid and reliable viscoelastic data of the human vocal fold cover at frequencies of up to 250 Hz. [Work supported by NIH.]
Multi-component synthetic model of the human larynx for investigating laryngeal fluid-structure interactions
Authors: Drechsel James , Hamilton Brianne , Jepsen Adam , Munger Jacob , Pickup Brian , Pulsipher Allyson , Thomson Scott
Published: October 2013

Synthetic continuum models of the vocal folds, though only relatively recently developed, have found significant use in studying the flow-induced vibrations of the vocal folds. The advantages of these models include long lifetime and reasonable comparison with human vocal fold characteristics. However, the geometry typically employed is highly idealized, with uniformly shaped cross section and rigid mounting to rectangular plates. In this presentation, the development and characterization of a multi-component model of the human larynx is presented. The model includes the following synthetic components: multi-layer vocal folds consisting of materials with nonlinear stress-strain properties, cartilaginous and soft tissue framework, and posture control. The fabrication process, including extraction of geometric information from medical images, is summarized. Various aspects of the model are characterized to compare the model behavior with that of the human larynx. Measurements of the synthetic vocal fold material properties, including stress-strain dependence, tangent modulus, and Poissons ratio, are presented. Dependence on subglottal pressure of the model vibration frequency, flow rate, vibration amplitude, and other flow field and jet characteristics are quantified using high-speed imaging, flow visualization, and particle image velocimetry.
Use of cross correlation to estimate Green’s functions in the Pakistan-Himalayas
Authors: Frank Scott D. , Foster Anna E. , Ferris Aaron N.
Published: October 2013

Recent theoretical and observational work indicates that the time derivative of the Green’s function between two points can be estimated from ambient seismic noise recordings. Continuous seismograms from a temporary deployment of nine broadband seismographs in NE Pakistan (1992) are cross correlated and averaged over 73 days to obtain Green’s function estimates of the longitudinal, radial, and transverse components for all station combinations. In general, the time-averaged correlation functions show dispersion characteristics, which are analyzed using Hilbert transform filtering and wavelet transforms. Preliminary results show group velocities between 1.5 and 3.5 km/s for the period band between 2 and 20 s. In some cases, the noise correlation functions exhibit asymmetry between causal and acausal portions. This is interpreted as preferred directionality of the diffusive noise field. By comparing the peak energy at causal and acausal delay times, it appears the noise field propagates predominantly from the north-northeast during the analyzed time period.
Integrating seismic exploration methods into a geological sciences curriculum at Brigham Young Unversity
Authors: McBride John H. , Keach R. William
Published: October 2013

The continuing expansion in petroleum and other resource exploration and in geological hazard assessment for infrastructure development have combined to dramatically increase the need for training of university students in seismic imaging methods. This need is being met at Brigham Young University (BYU) by forming alliances or collaborations with private industry and government in order to provide financial support for research using seismic techniques, to obtain access to proprietary datasets, and to place students in the workplace as part of their university experience. Infrastructure support has been provided by BYU in the form of acquisition of seismic recording equipment, procuring of state-of-the-art software for data processing and geologic mapping, and building of a dedicated 3D visualization lab. This infrastructure creates an environment that mimics research and exploration programs in private industry. Seismic geophysical research foci at BYU include (1) seismic characterization of deep reservoirs for carbon sequestration, (2) 3D seismic attribute analysis for petroleum prospecting, (3) high-resolution seismic exploration applied to landslide and earthquake hazard assessments, (4) exploration of deep sedimentary basins that may be prospective for oil or gas, and (5) oilfield applications of seismic mapping in order to detect and map shallow faults that may function as leakage pathways.
Experimental design for acoustic characterization of a seismic exploration airgun array
Authors: Tashmukhambetov Arslan M. , Ioup George E. , Ioup Juliette W. , Sidorovskaia Natalia A. , Newcomb Joal J. , Stephens James M. , Rayborn Grayson H.
Published: October 2013

The Littoral Acoustic Demonstration Center (LADC) (participating institutions given in author list) is scheduled to perform an experiment in the Gulf of Mexico to characterize the underwater acoustic field of a seismic exploration airgun array. The design is constrained by the array lengths and hydrophone spacings of the ten four-channel LADC calibrated environmental acoustic recording system (EARS) buoys available for the measurements. Placement of the EARS arrays is determined to achieve best the design goals, given the constraints. The fixed mooring EARS hydrophone depths will vary from 100 to 1171 m, and near-surface ship-deployed phones will be used for shallower depths. Straight-line source boat paths of varying length and spacing have been calculated that redundantly fill all solid angle bins whose size is determined by small uncertainties in the array location and orientation [Robert Laws (2006), private communication]. Shot spacing is also a factor. Care is taken to have nearby shots to the EARS arrays for all bins. All direct paths are calculated including refraction. Data are presented in spherical and planar images to show angular and bin coverages and shot ranges. [Work supported in part by the Joint Industry Project through the International Association of Oil and Gas Producers.]
Suspended-sediment measurements in a fluvial environment using acoustic backscatter
Authors: Carpenter Wayne O. , Chambers James P. , Smith Christopher K. , Wren Daniel G. , Kuhnle Roger A.
Published: October 2013

The continued development of acoustic backscatter technology for suspended-sediment measurement is an important goal that, when attained, will result in sediment transport data of unprecedented quality and quantity. Towards this end, an instrumented raft has been deployed in an ephemeral stream in the North Mississippi area. The raft is used as a floating instrument platform that allows acoustic transducers to stay in contact with the water surface during stage changes caused by runoff into the stream channel. The single-frequency acoustic data is calibrated for both particle size and concentration using concurrent pumped samples of the water/sediment mixture collected from various levels above the stream bed. Data from several storm events has been acquired and will be presented, including time series of converted suspended-sediment concentration data and estimates of errors introduced during the conversion process.
Role of glottal-pulse rate, vocal-tract length, and original talker upon judgements of speaker sex and age
Authors: Smith David R. R. , Walters Thomas C. , Patterson Roy D.
Published: October 2013

Glottal-pulse rate (GPR) and vocal-tract length (VTL) are important determinants of the perceived sex and age of the speaker [D. R. R. Smith and R. D. Patterson, J. Acoust. Soc. Am. 118, 3177–3186 (2005)]. Our previous research simulated the voices of variously-sized speakers of both sexes by manipulating the recorded vowels of one adult male talker. The current study explored whether there are additional cues in the voices of men, women, and children that influence judgements of speaker sex and age. We manipulated the recorded vowels of an adult man, adult woman, young boy, and young girl, and determined the effect upon the distribution of sex and age responses (man, woman, boy, girl). Results show that the distribution of sex and age judgements across the GPR-VTL plane is heavily influenced by GPR and VTL, but it is also affected by the original talker’s size (or age). The effect of original talker appears to be mainly due to the consistent difference between oral-pharyngeal length ratios of children and adults. We also report gender differences in male and female listeners across the GPR-VTL plane; adult men and women listeners show somewhat different biases. [Research supported by UK MRC (G9900369, G0500221) and German Volkswagen Foundation (1/79 783).]