bluuebunny/crossref_metadata_2025 huggingface dataset:
Determining flat interface reflection coefficients using forward scattering from a rippled sediment interface
Authors: Williams Kevin L.
Published: October 2013

For sediment interfaces that are very rough on the scale of the acoustic wavelength (i.e., kh greater than 1 where k is 2*π/wavelength and h is the rms roughness of the water/sediment interface) it is possible to estimate what the reflection coefficient would be if the interface were flat. In order to do so, a large ensemble of forward scattering measurements are needed in order to reduce the statistical uncertainty of the estimated reflection coefficient. In addition to the statistical uncertainty there can be biases in the estimate (for some grazing angles) that must be taken into account. The above conclusions will be supported through the use of monte carlo simulations of scattering from a rippled interface. The simulations are carried out in the context of discriminating between alternative acoustic models of sand sediments. [Work supported by ONR.]
Bayesian inversion of multi-frequency reflection data with strongly correlated errors for density gradients
Authors: Dettmer Jan , Dosso Stan E. , Holland Charles W.
Published: October 2013

This paper develops a non-linear Bayesian inversion for multi-frequency reflection-loss data with strongly correlated data errors to resolve density and sound-velocity gradients which are often observed in the uppermost sediment layer. Although data errors are usually assumed to be independent in geoacoustic inversion, in reality measured data often show strong error correlations. The inversion developed here is designed to take error correlations into account. A full data covariance matrix is estimated from initial residuals of non-uniformly sampled data. This covariance matrix is then used in the likelihood function of a fast Gibbs sampler to sample the posterior probability density and provide parameter estimates and credibility intervals. Rigorous statistical tests are applied to the resulting data residuals to illustrate the benefits of this error treatment. The approach is applied to reflectivity data collected at a site characterized by low-velocity, water-saturated sediments in the Strait of Sicily. Density and sound-speed gradients are clearly resolved by the reflectivity data and agree with core measurements from the experiment site within the credibility bounds.
Audiogram variability in normal bottlenose dolphins
Authors: Tarakanov Mikhail B. , Pletenko Mikhail G. , Popov Vladimir V. , Supin Alexander Ya.
Published: October 2013

Audiograms have been obtained in about a dozen of odontocete species, but mostly in one or two individuals each. However, some inter-individual difference in hearing sensitivity is inevitable. Therefore, a representative number of animals should be investigated to get a normal audiogram standard. In the present study, an attempt has been made to estimate the audiogram scatter among normal bottlenose dolphins. Measurements were made in dolphins captured in wild and kept in captivity 3 to 5 months, using auditory evoked potential technique (envelope following response) to measure hearing thresholds in far acoustic field. Seven subjects, 5 males and 2 females, provisionally from 3 to 15 years old, were investigated during the summer season of 2004. Hearing thresholds were measured at frequencies from 8 to 152 kHz with quarter-octave steps. All the subjects had qualitatively similar audiograms. The best sensitivity was from 38.9 dB re 1 uPa (at 32 kHz) to 51.9 dB (at 16 kHz), with a minimum of the averaged audiogram of 47.1 dB at 45 kHz. High-frequency cut-off was 152 kHz at a level of 40 dB above the lowest threshold. Standard deviation of threshold was from 4.1 to 10.3 dB. [Work supported by RFBR and Russian President Grants.]
Auditory evoked potential (AEP) measurements in stranded rough-toothed dolphins (Steno bredanensis)
Authors: Cook Mandy L. H. , Manire Charles A. , Mann David A.
Published: October 2013

Thirty-six rough-toothed dolphins (Steno bredanensis) live-stranded on Hutchinson Island, FL on August 6, 2004. Seven animals were transported to Mote Marine Laboratory for rehabilitation. Two auditory evoked potential (AEP) measurements were performed on each of five of these dolphins in air using a jawphone to present acoustic stimuli. Modulation rate transfer functions (MRTFs) were measured to establish how well the auditory system follows the temporal envelope of acoustic stimuli. A 40 kHz stimulus carrier was amplitude modulated (AM) with varying rates ranging from 200 Hz to 1800 Hz, in 200 Hz steps. The best AM-rate from the first dolphin tested was 1500 Hz. This AM rate was used in subsequent AEP measurements to determine evoked-potential hearing thresholds between 5000 and 80000 Hz. These findings show that rough-toothed dolphins can detect sounds between 5 and 80 kHz, and are most likely capable of detecting frequencies much higher than 80 kHz. MRTF data suggest that rough-toothed dolphins have a high temporal resolution, similar to that of other cetaceans.
Estimating the uncertainty of geoacoustic parameters of a range-dependent environment
Authors: Fallat Mark , Dosso Stan , Nielsen Peter
Published: October 2013

In this study, data from a range-dependent environment are inverted to obtain estimates of the geoacoustic properties and their uncertainties. The technique consists of combining the results of a series of range-independent inversions to produce a model of the range-dependent environment. A rigorous uncertainty analysis provides a way of discerning whether variations in the inversion results are due to range-dependent features of the environment or simply due to uncertainty/variability in the results. Broadband acoustic data from a track off the island of Sicily were analyzed. Ground-truth information in the form of core measurements and a high-resolution seismic profile were also collected and used for verification of the results. The method of fast Gibbs sampling (FGS) was used to estimate the uncertainties of the geoacoustic properties. FGS is based on a Bayesian approach to inversion which samples the posterior probability distribution to estimate marginal probability distributions and parameter correlations. Marginal probability distributions were computed at various points along the track and compared to the ground-truth information. Overall, the analysis showed that the dominant range-dependent features of the environment could be estimated.
Bounding the error on bottom estimation for multi-angle swath bathymetry sonar
Authors: Mullins Geoff K. , Bird John S.
Published: October 2013

With the recent introduction of multi-angle swath bathymetry (MASB) sonar to the commercial marketplace (e.g., Benthos Inc., C3D sonar, 2004), additions must be made to the current sonar lexicon. The correct interpretation of measurements made with MASB sonar, which uses filled transducer arrays to compute angle-of-arrival information (AOA) from backscattered signal, is essential not only for mapping, but for applications such as statistical bottom classification. In this paper it is shown that aside from uncorrelated channel to channel noise, there exists a tradeoff between effects that govern the error bounds on bottom estimation for surfaces having shallow grazing angle and surfaces distributed along a radial arc centered at the transducer. In the first case, as the bottom aligns with the radial direction to the receiver, footprint shift and shallow grazing angle effects dominate the uncertainty in physical bottom position (surface aligns along a single AOA). Alternatively, if signal from a radial arc arrives, a single AOA is usually estimated (not necessarily at the average location of the surface). Through theoretical treatment, simulation, and field measurements, the aforementioned factors affecting MASB bottom mapping are examined. [Work supported by NSERC.]
3D spatial sampling with a cylindrical multibeam sonar array
Authors: Brogan Daniel S. , de Moustier Christian P.
Published: October 2013

Various beam pair combinations can be formed with cylindrical multibeam sonar arrays to obtain a 3D spatial sampling of a patch of seafloor for each ping. This capability is explored with a 286 deg sector cylindrical array transmitting a stepped FM pulse over a 243 deg vertical fan beam centered on nadir and receiving with twenty-seven beam pairs, symmetrically steered about nadir in the fore-aft direction and spaced at 7.16 deg intervals across track. Conventional conjugate product techniques yield two across-track profiles of 26 soundings each (52 phasors total) per ping. However, by combining one or two phasors along-track and one, two or three phasors across-track, soundings can be obtained at the spatial bisectors of the angles between the 52 phasors. This yields three profiles consisting of 51 soundings each, for a total of 153 soundings. This effectively creates a 3D patch of detected seafloor for each ping, which may overlap with the patches from adjacent pings depending on the sonars attitude changes and altitude above the seafloor. [Work supported by NRL-SSC grant N00173-00-1-G912 and NOAA grant NA170G228.]
Assessment of atmospheric models for tele-infrasonic propagation
Authors: McKenna Mihan , Hayek Sylvia
Published: October 2013

Iron mines in Minnesota are ideally located to assess the accuracy of available atmospheric profiles used in infrasound modeling. These mines are located approximately 400 km away to the southeast (142) of the Lac-Du-Bonnet infrasound station, IS-10. Infrasound data from June 1999 to March 2004 was analyzed to assess the effects of explosion size and atmospheric conditions on observations. IS-10 recorded a suite of events from this time period resulting in well constrained ground truth. This ground truth allows for the comparison of ray trace and PE (Parabolic Equation) modeling to the observed arrivals. The tele-infrasonic distance (greater than 250 km) produces ray paths that turn in the upper atmosphere, the thermosphere, at approximately 120 km to 140 km. Modeling based upon MSIS/HWM (Mass Spectrometer Incoherent Scatter/Horizontal Wind Model) and the NOGAPS (Navy Operational Global Atmospheric Prediction System) and NRL-GS2 (Naval Research Laboratory Ground to Space) augmented profiles are used to interpret the observed arrivals.
An analysis of seismic and acoustic signals from the June 3, 2004 Washington state bolide
Authors: Arrowsmith Stephen , Hedlin Michael , Ceranna Lars , Edwards Wayne
Published: October 2013

On June 3rd, 2004 a spectacular bolide was reported over British Columbia, Washington, Oregon and Idaho. In addition to eyewitness accounts and video recordings, the event was recorded on a number of seismometers in the Pacific Northwest Seismograph network and at infrasound arrays in Washington State and California. Using the NRL-G2S atmospheric model for the time of the event, source locations have been determined with seismic and acoustic signals separately. Estimates of the yield and acoustic efficiency of the explosion have also been determined. By simulating the propagation of infrasound through the atmosphere, the arrival of discrete acoustic phases at the infrasound arrays has been modeled.
Multiple array infrasound observations in the Netherlands
Authors: Evers Läslo , Haak Hein
Published: October 2013

Infrasound in the Netherlands is observed with multiple arrays. The current architecture consists of 4 arrays. These arrays vary in aperture from 30 to 1500 m while the number of microbarometers ranges from 6 to 16 per array. Continuous observation of infrasound implies a huge number of automatic detections per year. In other words, thousands of coherent waves cross the arrays each year. Although a lot of sources can be identified, there are still unknown sources having a coherent infrasonic signature. Among the identified sources are: supersonic airplanes, bolides, severe weather, oceanic waves, volcano explosions, and military activity. Current efforts in source identification concentrate on the integration of infrasonic and seismic data. Furthermore, atmospheric characteristics are included such as the state of the boundary layer and propagation conditions in the higher atmospheric, i.e., stratospheric winds and temperatures. In this presentation the influence of the atmosphere on the detection capability will be shown. Furthermore, the detailed analysis of specific sources shows the enormous potential of infrasound as atmospheric probe and monitoring technique.
So/ren Buus. Thirty years of psychoacoustic inspiration
Authors: Poulsen Torben
Published: October 2013

So/ren Buus did his MSc at the Acoustics Laboratory, Technical University of Denmark (DTU), in 1975 on the topic headphone calibration. He showed the importance of reliable reference values for psychoacoustic research and So/ren was a great inspiration for my work [Scand. Audiol. 20, 205–207 (1991); 27, 105–112 (1998)]. Already from the seventies, temporal integration of loudness has been a major topic in the collaboration with So/ren [Buus et al., J. Acoust. Soc. Am. 105, 3464–3480 (1999)] and the measurements of temporal integration over a wide range of presentation levels led to the important finding about the shape of the loudness function [Buus et al., J. Acoust. Soc. Am. 100, 669–680 (1997)]. So/ren talked about the importance of the psychophysical procedure and the influence from the procedure on the results [Buus, Proceedings 19th Danavox Symposium (2001), pp. 183–226]. The goal was to obtain reliable, unbiased, and precise results. An overview of some of the above investigations will be presented together with recent results from a MSc project on headphone calibration of short duration sounds for ABR measurements.
A variational approach to modeling the vibration of timber joist floors
Authors: Fox Colin , Chung Hyuck
Published: October 2013

We present a comprehensive variational model for the vibration of timber joist floors and a simple computer algorithm for finite, particularly rectangular, floors. We allow for floor constructions that are typical in the New Zealand context, consisting of edge-supported timber joists with flooring material above, often a suspended ceiling below with absorptive material in the cavity, and a range of joint types such as gluing or nailing. The model and algorithm are structured in such a way that a component can easily be either added to, or removed from, the structure. Hence the configuration may be made progressively more complex from the simplest floor-joists type to floor-joists-ceiling with cavity air and damper-spring connectors.
Free choice task effects in cross-linguistic stop perception
Authors: Kochetov Alexei
Published: October 2013

This paper examines the identification of stop place and secondary articulation using a free choice task. Russian syllable-initial and syllable-final stops /p pj t tj/ in nonsense utterances were presented to Russian and Japanese listeners (N=30). Correct identification rates for place and secondary articulation of the target consonants were determined based on written responses (in Cyrillic or Katakana). Both groups of listeners showed better identification of syllable-initial stops compared to syllable-final stops. Among the consonants, /p/ was identified better, and /pj/ was identified worse than the other stops. Native listeners performed better than non-native listeners. The overall correct identification rates were lower than (yet strongly correlated with) the rates previously obtained with the same stimuli using a forced choice phoneme identification task. The lower identification rates in the current study can be explained in part by the errors involving the segmentation and syllabification of palatalized stops. Thus, the palatal articulation of the syllable-final palatalized /pj/ was often interpreted as independent of the stop (e.g., /tapj api/ rendered as /taj papi/ or /tjap api/). It is concluded that the free choice task can successfully complement the forced choice task, providing additional information about the perception of secondary palatalization. [Supported by SSHRC.]
The phonetic rhythm/syntax headedness connection: Evidence from Tagalog
Authors: Bird Sonya , Fais Laurel , Werker Janet
Published: October 2013

Ramus, Nespor, and Mehler [Cognition (1999)] show that the rhythm of a language (broadly: stress- versus syllable- versus mora-timing) results from the proportion of vocalic material in an utterance (%V) and the standard deviation of consonantal intervals (delta-C). Based on 14 languages, Shukla, Nespor, and Mehler [submitted] further argue that rhythm is correlated with syntactic headedness: low %V is correlated with head-first languages (e.g., English); high %V is correlated with head-final languages (e.g., Japanese). Together, these proposals have important implications for language acquisition: infants can discriminate across rhythm classes [Nazzi, Bertoncini, and Mehler, J. Exp. Psych: Human Perception and Performance (1998)]. If rhythm, as defined by %V and delta-C, can predict headedness, then infants can potentially use rhythm information to bootstrap into their languages syntactic structure. This paper reports on a study analyzing rhythm in a language not yet considered: Tagalog. Results support the Shukla et al. proposal in an interesting way: based on its %V and delta-C, Tagalog falls between head-first and head-last languages, slighty closer to the head-first group. This placement correlates well with the fact that, although Tagalog is said to be primarily head-first syntactically, head-last phrases are permitted and common in the language.
A comparison of the acoustic characteristics of American English and Cantonese vowels
Authors: Zee Eric
Published: October 2013

The study compares the formant frequencies of the American English vowels [i, ε, ■, ■, u, I, U] (Peterson and Barney, 1952) and [i, ε, a, ■, u, I, U] in Cantonese (Zee, 2004). Results of the comparison show that the differences in formant values for the vowels between the two languages vary according to vowel type and gender. Between male speakers of the two languages, the differences in F-values are minimal for [i] and [■]. For [ε, u], the difference between the two groups is mainly in F2, with [ε] having a larger F2 and [u] a smaller F2 for Cantonese speakers. [■] in American English has smaller F1 and F2 than [a] in Cantonese. [I, U] occupy the position in between the level of [i, u] and level of [ε, ■] in the F1/F2 plane for American English speakers, and there is a noticeable difference in F2 between [I] and [ε] and between [U] and [■]. For Cantonese speakers, [I, U] are on the same level of [ε, ■], and the difference in F2 is minimal between [I] and [ε] and between [U] and [■]. The differences between female speakers of the two languages will also be presented.
The role of psychophysical difference in the discrimination of non-native contrasts
Authors: Harnsberger James , Shrivastav Rahul , Skowronski Mark
Published: October 2013

Models of cross-language speech perception have shown only limited success in predicting the discriminability of non-native contrasts. These failures may be attributed partly to an inability to quantify the phonetic similarities between non-native speech sounds and between non-native speech sounds and native speech categories. This study represents an attempt to quantify gross psychophysical differences between consonants (e.g., the absolute difference between two consonants as represented in the peripheral auditory system). Two metrics were evaluated with a set of nasal consonant place contrasts from Malayalam. The first focused only on formant transitions at nasal-vowel boundaries (critical cue measure) while the second compared the spectrum of temporal windows spanning the entire length of both syllables that constituted a contrast (whole stimulus measure). The critical cue measure was presumed to have the advantage of incorporating only perceptually relevant information, while the whole stimulus measure was thought to be preferable if the relevant cues were poorly understood and/or were distributed throughout the syllable. The results showed a significant correlation (r=0.63) between the critical cue measure and discrimination scores. The whole stimulus measure showed only a weak correlation (r=0.35) unless a set of outliers (bilabial contrasts) was excluded (r=0.80).
Processing voiceless vowels in Japanese: Effects of language-specific phonological knowledge
Authors: Ogasawara Naomi
Published: October 2013

There has been little research on processing allophonic variation in the field of psycholinguistics. This study focuses on processing the voiced/voiceless allophonic alternation of high vowels in Japanese. Three perception experiments were conducted to explore how listeners parse out vowels with the voicing alternation from other segments in the speech stream and how the different voicing statuses of the vowel affect listeners’ word recognition process. The results from the three experiments show that listeners use phonological knowledge of their native language for phoneme processing and for word recognition. However, interactions of the phonological and acoustic effects are observed to be different in each process. The facilitatory phonological effect and the inhibitory acoustic effect cancel out one another in phoneme processing; while in word recognition, the facilitatory phonological effect overrides the inhibitory acoustic effect.
The effect of sweep direction on avian auditory brainstem responses
Authors: Brittan-Powell Elizabeth , Lauer Amanda , Callahan Julia , Dooling Robert , Leek Marjorie , Gleich Otto
Published: October 2013

In mammals, brief rising frequency sweeps result in increased amplitudes for both auditory brainstem response (ABR) and compound action potential (CAP) recordings (Dau, 2000; Shore and Nuttall, 1985). The rising sweep is thought to result in increased synchronous activity. Changing the direction of the sweep exaggerated the delay of processing along the basilar membrane and decreased synchrony of neural responses. Here we recorded ABRs from budgerigars, canaries, and zebra finches to a variety of stimulus parameters, including rising and falling sweeps with different sweep rates, determined by changing duration and frequency range. Both linear and nonlinear sweeps in frequency over time were tested. Results show that rising sweeps produce larger peak amplitudes, shorter latencies and changes in wave morphology such as a narrower wave 1 width than falling sweeps, suggesting greater synchrony of response to sweeps moving from low to high frequency. These data are consistent with mammalian results, but with a different time scale related to temporal characteristics of cochlear stimulation on the short basilar papilla in birds. [Work supported by NIH DC00198, DC001372, DC04664.]
Variation in acoustic behavior of delphinids in the Pacific Ocean based on school size and species composition
Authors: Rankin Shannon , Barlow Jay
Published: October 2013

Variation in acoustic behavior based on school size and species composition was examined for surveys in the eastern tropical Pacific (2000), along the U.S. West Coast (2001), and in the U.S. EEZ surrounding Hawaii (2002). Sounds were monitored using a towed hydrophone array, and vocal schools were defined as those producing any combination of whistles, burst pulses, and/or echolocation clicks. Delphinid schools containing mixed species were consistently more vocal than single species schools. Vocal schools of Stenella attenuata, S. longirostris, Delphinus delphis, and Lissodelphis borealis were significantly larger than non-vocal schools. Vocal schools of Tursiops truncatus and Grampus griseus were somewhat larger than non-vocal schools, although this relationship was not significant. There was no relationship between group size and vocal activity for S. coeruleoalba, Steno bredanensis, and Globicephala spp. For species without a strong group size effect, all but T. truncatus were more vocal in the Hawaiian waters. The ability to use acoustic techniques in dolphin population estimation depends on their effectiveness in consistently detecting dolphin schools. This study suggests that small single-species schools of S. attenuata, S. longirostris, D. delphis, and L. borealis are more likely to be missed during acoustic monitoring in these regions.
Whale song analyses using bioinformatics sequence analysis approaches
Authors: Chen Yian A. , Almeida Jonas S. , Chou Lien-siang
Published: October 2013

Animal songs are frequently analyzed using discrete hierarchical units, such as units, themes and songs. Because animal songs and bio-sequences may be understood as analogous, bioinformatics analysis tools DNA/protein sequence alignment and alignment-free methods are proposed to quantify the theme similarities of the songs of false killer whales recorded off northeast Taiwan. The eighteen themes with discrete units that were identified in an earlier study [Y. A. Chen, masters thesis, University of Charleston, 2001] were compared quantitatively using several distance metrics. These metrics included the scores calculated using the Smith-Waterman algorithm with the repeated procedure; the standardized Euclidian distance and the angle metrics based on word frequencies. The theme classifications based on different metrics were summarized and compared in dendrograms using cluster analyses. The results agree with earlier classifications derived by human observation qualitatively. These methods further quantify the similarities among themes. These methods could be applied to the analyses of other animal songs on a larger scale. For instance, these techniques could be used to investigate song evolution and cultural transmission quantifying the dissimilarities of humpback whale songs across different seasons, years, populations, and geographic regions. [Work supported by SC Sea Grant, and Ilan County Government, Taiwan.]
Autonomous and ship-cabled, bottom mounted sonar systems—Development, uses and issues associated with transitioning to ocean observatories
Authors: Williams Kevin L. , Light Russell D. , Miller Vernon W.
Published: October 2013

Three bottom mounted sonar systems will be described that were built over a span of fifteen years. The complexity of deployment and sophistication of the tasks performed increased with each system. The first system is an autonomous tower with rotating sonar designed to examine backscattering from an area within 50 m radius of the tower. The second is a ship-cabled system that includes a diver movable tower and separate buried array for examining both backscattering and acoustic penetration into sediments. The last is a ship-cabled rail/tower system designed to carry out forward scattering and synthetic aperture backscattering measurements. All three systems are designed to remain deployed for time periods up to a couple of months. After describing the systems, their deployment and some example results, recent efforts will be described that are aimed at transitioning these types of systems to cabled ocean observatories. The overall goal of the talk is to indicate both the level of complexity that can be envisioned for bottom mounted systems as well as the new issues that must be addressed in moving to cabled ocean observatories. [Work supported by ONR.]
The application of acoustic radiation force for molecular imaging and drug delivery
Authors: Dayton Paul A. , Ferrara Katherine W.
Published: October 2013

Acoustic radiation force is exerted on objects in an acoustic field. By optimizing acoustic parameters to maximize this force, ultrasound contrast agents can be manipulated and concentrated with an acoustic field. This technique can be used to enhance molecular imaging and drug delivery. Ultrasonic molecular imaging employs contrast agents such as microbubbles, nanoparticles, or liposomes coated with ligands specific for receptors expressed on cells at sites of angiogenesis, inflammation, or thrombus. Concentration of these highly echogenic contrast agents at a target site enhances the ultrasound signal received from that site, promoting ultrasonic detection and analysis of disease states. It is demonstrated that acoustic radiation force can be used to displace targeted contrast agents to a vessel wall, greatly increasing the number of agents binding to available surface receptors. Radiation force can also be used for microparticle-carrier based drug delivery. Acoustically active drug-carrier vehicles can be concentrated with radiation force, and then disrupted with high-intensity ultrasound bursts, resulting in local delivery of the therapeutic agent. This talk will discuss simulations and experimental results demonstrating these applications.
A new targeted drug delivery method using ultrasound and acoustically active lipospheres
Authors: Shortencarier Michaelann , Bloch Susannah , Dayton Paul , Ferrara Kathy , Matsunaga Terry , Labell Rachel , Schumann Patricia
Published: October 2013

The goal is to create a strategy for localized drug delivery using engineered delivery vehicles and ultrasound energy. These drug delivery vehicles, referred to as acoustically active lipospheres (AALs), consist of small gas bubbles surrounded by thick oil shells (where drugs can be carried) and are enclosed by an outermost lipid layer. Ultrasound radiation force can be used to displace these vehicles near the blood vessel wall, after which a higher intensity pulse can fragment the vehicle and transfer its contents to the endothelium. Blood velocity ranges from 1 to 10 mm/s in the microvasculature. Therefore, agents in capillaries insonified by a transducer with a 1 mm focal beam width for 0.1 to 1 seconds can be displaced of 1 to 2 mm. Delivery vehicles containing various fluorescent dyes within the oil layer are exposed to ultrasound in cell chambers or flowing vessels. Fluorescence intensity increases more than 10-fold with application of radiation force and fragmentation, both over no exposure and over fragmentation pulses alone (both P<0.001). This implies radiation force is necessary to bring AALs into proximity of the cell monolayer before their destruction in order for drug delivery to occur.
Visual feedback for retuning to just intonation intervals
Authors: Ayers R. Dean , Nordquist Peter R. , Corn Justin S.
Published: October 2013

Musicians become used to equal temperament pitch intervals due to their widespread use in tuning pianos and other fixed-pitch instruments. For unaccompanied singing and some other performance situations, a more harmonious blending of sounds can be achieved by shifting to just intonation intervals. Lissajous figures provide immediate and striking visual feedback that emphasizes the frequency ratios and pitch intervals found among the first few members of a single harmonic series. Spirograph patterns (hypotrochoids) are also especially simple for ratios of small whole numbers, and their use for providing feedback to singers has been suggested previously [G. W. Barton, Jr., Am. J. Phys. 44(6), 593–594 (1976)]. A hybrid mixture of these methods for comparing two frequencies generates what appears to be a three dimensional Lissajous figure—a cylindrical wire mesh that rotates about its tilted vertical axis, with zero tilt yielding the familiar Lissajous figure. Sine wave inputs work best, but the sounds of flute, recorder, whistling, and a sung ‘‘oo’’ are good enough approximations to work well. This initial study compares the three modes of presentation in terms of the ease with which a singer can obtain a desired pattern and recognize its shape.
Directivity measurements of the violin during performance
Authors: Hardy Jean-François , Migneron Jean-Gabriel
Published: October 2013

Many studies have shown that directivity of musical instruments is significant for the perceived sound within the hall and for performer’s ease of hearing each other. The directivity patterns explain in part the differences between many common or special orchestral stage plots. Measurements of the violin’s directivity have been performed using an acoustical intensimetry procedure. The precise directivity characteristics of isolated tones have been compared with the mean directivity resulting from performance of four extracts chosen among the orchestral repertoire. Results, which were measured in both horizontal and vertical planes, show interesting differences between the average directivity of each test. They lead to links with few important distinctions in the traditional violin’s positions inside the orchestra.
Soprano and source: A laryngographic analysis
Authors: Bateman Laura Anne
Published: October 2013

Popular music in the 21st century uses a particular singing quality for female voice that is quite different from the trained classical singing quality. Classical quality has been the subject of a vast body of research, whereas research that deals with non-classical qualities is limited. In order to learn more about these issues, the author chose to do research on singing qualities using a variety of standard voice quality tests. This paper looks at voice qualities found in various different styles of singing: Classical, Belt, Legit, R&B, Jazz, Country, and Pop. The data was elicited from a professional soprano and the voice qualities reflect industry standards. The data set for this paper is limited to samples using the vowel [i]. Laryngographic (LGG) data was generated simultaneously with the audio samples. This paper will focus on the results of the LGG analysis; however, an audio analysis was also performed using Spectrogram, LPC, and FFT. Data from the LGG is used to calculate the contact quotient, speed quotient, and ascending slope. The LGG waveform is also visually assessed. The LGG analysis gives insights into the source vibration for the different singing styles.
Rational approximations of surface impedance operators on curved surfaces with application to high-frequency scattering by thin shells
Authors: Calvo David C.
Published: October 2013

In the analytical solution of scattering and radiation problems on curved surfaces using Fourier transforms, surface impedance functions featuring ratios of Hankel functions arise. Recently, an approach of approximating the impedance by a rational function was introduced in which the squared transform variable is replaced by a differential operator. By taking into account the impedance function poles in the rational approximation, an accurate and efficient numerical scheme is obtained applicable to wide-frequency ranges and wide-scattering angles where creeping waves are important. The rational approximation and operator introduction in effect creates an inverse Fourier transform operator so explicit residue calculus inversion is not needed if numerical results are desired. For general convex surfaces, the approximate impedance operator is a wide-angle on-surface radiation condition operator with more accuracy than the narrow-angle one of Kriegsmann et al. The use of rational approximations resembles that of Collins et al. for the square-root function in ocean acoustics and DiPerna & Feit for the flat plate, the important difference being the curvature. Results of using this approach for two and three-dimensional scattering problems will be presented along with recent application to scattering by thin cylindrical and spherical shells at high frequencies. [Work supported by ONR.]
The effect of [h] on tonal development in Nahuatl
Authors: Guion Susan G. , Amith Jonathan D.
Published: October 2013

In both its classical and modern forms, Nahuatl is usually described as having penultimate accent (with little discussion as to whether this is a phrase- or word-level phenomena). However, some varieties of Mexican Guerrero Nahuatl have recently been described as having word accent in locations related to the position of a historical non-word-final coda *h. Here, the hypothesis is investigated that coda *h lowered the fundamental frequency (F0) of the tautosyllabic vowel and that a H−L pitch contour was subsequently incorporated into the lexical representation of the word as *h was weakened and lost. Recordings were made of four dialects at varying stages of *h loss and tonal innovation. Six speakers from each dialect were recorded producing words in phrase medial and phrase final positions, some with historical coda *h and some without, and the F0 of each syllable in these words measured. The results indicated that the new accentual patterns found in some dialects have their origin in the phonetic lowering of F0 in syllables containing coda *h. It also seems that once a new accentual pattern is developed and the *h lost, the resulting phonologized pattern may not correspond to the phonetic locus of the sound change.
Glottalized consonants in Oaxaca Chontal
Authors: Avelino Heriberto , Maddieson Ian
Published: October 2013

Lowland Oaxaca Chontal, a language generally classified as Hokan and hence related to Yuman and Pomo languges, is now spoken by only a small percentage of the Chontal people who live on the Pacific coast of Oaxaca state, Mexico. Recordings were made of seven speakers in their 60’s to 80’s in December 2003. The language has a series of glottalized obstruents some of which which vary in production between fricative and affricate realizations. Our data show the labio-dental and lateral are the most likely to have fricative realizations, the coronals are regularly affricates and the velar is regularly a stop. These segments are contrastive but morphologically related to the voiceless fricatives of the language. This is demonstrated by one common plural formation process which adds glottalization to a final consonant (e.g. /apix/ ‘‘stone,’’ /apik’/ ‘‘stones’’). After a vowel the same morpheme is realized as a glottal stop (e.g. /u/ ‘‘eye,’’ /u/ ‘‘eyes’’). However, not all sequences of voiceless fricative + glottal stop are realized as glottalized obstruents (e.g. /ase/ ‘‘atole’’). Chontal also has glottalized nasals and approximants. As in other languages the accompanying glottal constriction is variable in degree and timing.
Experimental study of aerosol concentration in flow-through, low-frequency resonators
Authors: Meegan Douglas , Smith Justin , Wright Wayne
Published: October 2013

An experimental method to study the concentration of micron-sized aerosols in a low-frequency sound field was developed. The physical mechanism for acoustic aerosol concentration in a low-frequency sound field is the asymmetric Stokes drag which has been predicted to exceed the effects of radiation pressure for typical aerosol sizes [Meegan and Ilinskii, J. Acoust. Soc. Am. 114, 2387 (2003)]. Related experiments were conducted in which 5 micron aerosol was drawn through a small duct that was driven in a transverse resonant mode with peak sound pressure levels of greater than 150 dB re 20 microPascals and frequencies in the range 1 to 10 kHz. The aerosol stream was illuminated by a laser sheet through the transparent walls of the duct in order to visualize (by video) the effects of the sound field. The experiments confirm the basic feature of the asymmetric Stokes drag model—specifically, the aerosol is observed to concen- trate along acoustic velocity nodes. Ongoing experiments to quantify the level of concentration will be described. [Work supported by RDECOM.]
The tube resonance model speech synthesizer
Authors: Manzara Leonard C.
Published: October 2013

The Tube Resonance Model (TRM) synthesizer is an articulatory speech synthesizer implemented in software. It directly emulates the resonant behavior of the oropharyngeal and nasal tracts using digital waveguides. The oropharyngeal cavity is subdivided into 8 regions of unequal length, where particular regions correspond to the human articulators of tongue, teeth, and mouth. The radius (cross-sectional area) of each region can be varied independently over time. The differences in radii between regions gives rise to differences in acoustic impedance, which is modeled using two-way scattering junctions. The nasal cavity is composed of 5 equal-length sections, and is connected to the vocal tract via another section (the velum) using a three-way scattering junction. The total length of the tube can be varied over a continuous range, allowing one to synthesize male, female, and juvenile voices.
Synthesizing speech acoustics from head and face motion
Authors: Barbosa Adriano V. , Yehia Hani C. , Daffertshofer Andreas , Vatikiotis-Bateson Eric
Published: October 2013

This work outlines a quantitative analysis of the relation between speech acoustics and the face and head motions that occur simultaneously [A. V. Barbosa, Ph.D. thesis, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil, 2004]. 2-D motion data is obtained by means of a video camera. An algorithm has been developed for tracking markers on the speaker’s face from the acquired video sequence [A. V. Barbosa, E. Vatikiotis-Bateson, and A. Daffertshofer, in Proceedings of the 8th ICSLP Interspeech 2004, Korea, 2004]. The motion domain is represented by the 2-D marker trajectories, whereas line spectrum pairs (LSP) coefficients and the fundamental frequency F0 are used to represent the speech acoustics domain. Mathematical models are trained to estimate the acoustic parameters (LSPs + F0) from the motion parameters (2-D marker positions). The estimated acoustic parameters are then used to synthesize the acoustic speech signal. Cross-domain analysis for undecomposed (i.e., full head + face) and decomposed (i.e., separated head and face) normalized 2-D motions is performed. Syntheses from each method using intelligibility tests and qualitative comparison of the original and synthesized utterances are being evaluated.
Characterization of voice pathologies from acoustic signals using wavelet analysis
Authors: Bentil Sarah A. , Yan Yuling
Published: October 2013

We present a method to quantitatively characterize voice abnormalities using wavelet analysis. The proposed method uses wavelets to decompose acoustic signals, acquired clinically from patients with normal and pathological voices, into their designated frequency/time components. These components contain valuable information on the unique dynamic properties of the vocal system and correlate with specific voice conditions. A comparative analysis of these vocal signals using spectrogram is also presented. These combined analyses provide comprehensive representation and quantitative characteristics of the vocal dynamics, which may provide key indication of vocal abnormalities. Further wavelet analysis of acoustic data evaluates variations in the characteristics of the vocal signal from one glottal cycle to the next. This is valuable since vocal signals representing most pathological voice productions exhibit inter-cycle variations in intensity or/and frequency. Our results of analysis show that the wavelet analysis can be used to characterize voice pathologies and provide information regarding the type and severity of the disorder. [Work supported by NSF awarded to Yan.]
Temporal features in TV news and weather forecasts
Authors: Shevchenko Tatiana I. , Uglova Natalia
Published: October 2013

The paper is aimed at investigating the specific features of temporal component as manifested in authentic TV speech, news and weather forecasts of the three channels: NBC, Texas News, Philadelphia Fox. In our 10 min corpus (9 speakers, 5 men and 4 women) durational patterns and pauses between them as well as their ratio were measured. The data showed that on average a durational pattern lasts 2655 ms, while an average pause duration is 193 ms. Thus pausing does not take a major amount of time, while phonation is 14 times as long. Furthermore, the analysis reveals the abundance of short and extra short pauses which also stands for a rapid tempo. The temporal characteristics were correlated with regional affiliation, genre and gender distinctions. The speakers demonstrated uniformity in the basic temporal features determined by time limit constraints. The results of our investigation basically agree with previous research based on mass media interviews, reading and spontaneous monologues. However, our findings show that a salient feature of newsreaders speech is their ability to deliver an enormous volume of information at a very quick tempo, which is a real challenge to viewers.
Detection enhancement using multiple time-reversed guide sources in shallow water: Analysis of TREX04 data
Authors: Calvo David C. , Gaumond Charles F. , Fromm David M.
Published: October 2013

Detection in a monostatic, broadband, active sonar system in shallow water is degraded by propagation-induced spreading. In the TREX04 experiment, performed south of the Hudson Canyon off the coast of New Jersey, 0.25 sec LFMs were transmitted with 500 Hz bandwidths chosen over a 0.5–3.5 kHz range using the NRL 64 element source-receiver array. The transmissions were then echo-repeated by a distant ship at a range varying between 1–5 km. The echo-repeating ship also transmitted one-way, 1 s, LFMs which were used as guide-source signals. These guide-source signals, which contain environmental information, form the basis of a technique for improving detection without having explicit environmental knowledge. Using an empirical-orthogonal-function representation of the set of monostatic guide-source signals, echoes were convolved with the time-reversed orthogonal functions as part of a filter bank. The result is improved probability of detection of noisy echoes using multiple guide-source signals in comparison with a baseline probability of detection using matched-filtering. In this talk, ROC curve improvement is analyzed as a function of the many parameters, e.g., target depth, source aperture, bandwidth, number of guide sources and their spatial and temporal separation. Comparison with numerical simulations is also made. [Work supported by ONR.]
Implementation of a nearfield acoustic holography system based on pressure and velocity measurements
Authors: Harris Michael C. , Blotter Jonathan D. , Sommerfeldt Scott D.
Published: October 2013

Analytical models have indicated that a pressure and velocity-based nearfield acoustic holography (NAH) method will provide the same reconstruction resolution of current NAH methods with significantly fewer measurement locations. This would lead to a considerable savings in data acquisition time for scanning array systems and reduce the inefficiency of NAH for high spatial frequencies. The pressure and velocity-based NAH method will be introduced. Experimental results for a simply supported plate and cylinder will be presented. These results will be compared to results obtained using conventional NAH methods.
Multi-variate error analysis of beam-forming acoustic measurements in a wind-tunnel
Authors: Ramakrishnan Ramani , Kawall Greg , Bhullar Pushpinder , Ball Norman
Published: October 2013

Source localization has been in the forefront in acoustics, since quantification of the source power and its exact location is de rigueur for successful noise control. Starting from single microphone measurements, many different methods, progressively more successful and complex, have been attempted for source localization. Recently, beam-forming methods, due to their success in underwater acoustics and architectural acoustics, have been used in wind tunnel tests. These tests have been quite extensively utilized both in automotive and aircraft tests. Beamforming techniques use an array of microphones, arranged in different patterns, to detect the source location and source power. In beamforming, the array in effect beams, not in the physical sense, towards the source to determine its position. Various parameters determine the success of the beamforming techniques. Some of these parameters are: number of microphones, microphone spacing, array pattern, source frequency and signal analysis procedures. A series of microphone array tests were conducted at the national Research Council of Canada’s wind tunnel, with and without flow. The source location was known a priori. A multi-variate error analysis was performed to determine the importance of the different parameters. The results of the analysis will be presented in this paper.