bluuebunny/crossref_metadata_2025 huggingface dataset:
Two surround compositions: Crossing Boundaries and The Puzzle Revealed
Authors: Chasalow Eric
Published: October 2013

Crossing Boundaries (composed in 2000), was commissioned by Bates College to celebrate the millennium. The text aphorisms and reminiscences make a counterpoint of different spaces and moments to give different senses of the passage of historical and musical time. Musically, the piece moves from one large moment to the next one, usually reinforcing the phrasing of the text. Throughout, there is a shifting perception of just how fast we are moving. Musical sources include a Hebrew chant (which maintains a ghostly presence throughout the piece), Beethoven’s piano music, improvised jazz, analog synthesized electronic music, and distorted electric guitar. The Puzzle Revealed (2006) is a maquette for an evening-long intermedia work, The Puzzle Master, a retelling of the Icarus myth by poet F. D. Reeve. This piece was conceived to specifically exploit the BeoLab 5 loudspeakers in 5.1 configuration. Material in the piece derives from vocal sources and explores morphing techniques that may become prominent in the larger work. The envelopment provided by full-range 5.1 playback is used to test ideas about the range of possibilities for spectral fusion or disintegration as a dynamic feature of different sound objects.
Hyper-directionality in clicks from the sperm whale (Physeter macrocephalus)
Authors: Moehl Bertel , Wahlberg Magnus , Heerfordt Anders
Published: October 2013

Directivity is an important determinant of animal sonar performance but difficult to assess for large, free-ranging species. Recent field studies of sperm whales indicate usual clicks to be quite directional [directivity index: 27 dB at a transmitting cross section to wavelength ratio (2a/wl) of 8], with indications of even narrower beams. To obtain better measures of directivity, a fiber-optically linked, linear hydrophone array with up to ten receivers, spaced 50 m apart, has been designed. The array can be deployed to depths of 1 km and incorporates a transmitting transducer. The array was deployed off Andenes, Norway, in July 2003, 2004, and 2005. On five occasions, transmissions of short broadband pulses (peaking at 14 kHz, SL 135 dB re: 1 Pa) apparently induced sperm whales at ranges of about 2 km to train their sound beams towards the transmitter and lock them there. This implies beam-steering from the whales’ auditory system, having a high auditory directionality, and detection capability of signals at 65 dB re: 1 Pa. It resulted in a high yield of on-axis recordings with maximum directivity indices of 39 dB, incompatible with plane piston radiation at 2a/wl ratio of 8.
Some relationships among phase cancellation at a phase-sensitive receiving transducer, phase aberration in diagnostic medical imaging, and nonlinear imaging
Authors: Miller James G. , Wallace Kirk D. , Holland Mark R.
Published: October 2013

A 1975 J. Acoust. Soc. Am. article by Marcus and Carstensen [Marcus & Carstensen, ‘‘Problems with absorption measurements of inhomogeneous solids,’’ J. Acoust. Soc. Am. 52, 1334–1335 (1975)] reported perhaps the earliest study of potential artifacts in medical ultrasonics arising from phase-cancellation effects at the face of a phase-sensitive receiving transducer. This paper recognized the insights offered in a 1966 paper by Southgate [Southgate, ‘‘Use of power-sensitive detector in pulse-attenuation measurements,’’ J. Acoust Soc. Am. 39, 480–483 (1966)] proposing a phase-insensitive receiver based on the acousto-electric effect to reduce phase-cancellation effects. Also in the 1970s, the Thurston lab at Duke and our lab in St. Louis examined consequences of propagating an ultrasonic field through the intrinsically inhomogeneous medium of soft tissue. Subsequently, several laboratories developed and implemented sophisticated algorithms applied to signals from receiving transducer arrays to provide some improvement. One of the most significant strides in reducing aberration artifacts came about serendipitously with harmonic mode (nonlinear) imaging. We will present experimental studies from our laboratory that examine approaches for reducing the profound effects arising from phase cancellation at the face of a phase-sensitive receiving transducer on measurements of ultrasonic attenuation and backscatter. Measurements utilizing phase-insensitive receiving transducers based on the acoustoelectric effect and measurement using two-dimensional arrays of pointlike receivers to characterize tissue-mimicking materials and intrinsically anisotropic hearts will be discussed. [Work supported by NIH R37-HL40302 and R01-HL72761.]
Teaching ultrasound instrumentation in medical and dental schools
Authors: Stone Maureen
Published: October 2013

This presentation will describe teaching strategies for applying ultrasound, a commonly used instrument in medical schools, to studying a novel application, the tongue. These methods have been used with students in otolaryngology and dentistry as well as linguistics, engineering, and speech and hearing. Four areas are considered important for students to know. (1) Introduction to ultrasound principles and use of commercial machines. Students are taught basic principles of sound propagation including focused versus nondirectional sound waves, scan types, and tissue properties. Commercial machine features are explained, such as gain control, depth setting, and calibration. (2) Data collection for research versus clinical purposes. Students are taught procedural requirements for research studies, including the importance of choice of task, positioning of transducer, and head stabilization to allow normalization across subjects. (3) Reduction and analysis of the high-dimensional ultrasound images. Data conditioning includes understanding how to interpret images, identify structures of interest, determine artifacts, find and use references, and extract tongue surface contours from the images. (4) Interpretation of data. It is easy to see tongue differences, but harder to capture them numerically. Students learn tools to reduce contour dimensionality, average and compare contours and contour sequences. [Research supported by R01 DC01758 NIDCD.]
Use of ultrasound as educational tool in medicine
Authors: Everbach E. Carr
Published: October 2013

Ultrasound is an imaging and therapy technology that is becoming increasingly important in modern medicine. Though only a fraction of physicians nationwide uses ultrasound in their practices, most medical students and many technicians receive an overview of the principles of ultrasound as part of their training. Often this overview is the only introduction to acoustics, and can be used as an educational tool to raise broader issues. This talk will describe the basic education in biomedical ultrasound obtained by most physicians and healthcare workers, and will discuss what is left out that should be part of medical education.
Amplitude fluctuations within musical instrument sounds because of impulse reflections
Authors: Bader Rolf
Published: October 2013

Musical instrument sounds nearly always show amplitude fluctuations in their overtones within the quasisteady state of the sound.These fluctuations make the sound more lively and are found in blown instruments like the saxophone or clarinet, in string instruments like the guitar or the violin, or in percussion instruments. The reason for this can be found within a feature common to all musical instruments, their impulse-driven behavior. Not only do the blown instruments work with impulses; the string forces of plucked, strucked, or bowed instruments of the top plate are also an impulse train. So, when looking at the system during the steady state not like one of standing waves but of impulses being reflected at different inhomogeneties within the structure, these reflections can be shown to be the reason for the amplitude fluctuations. The mechanism is caused by the fact that the energy within an impulse is split into potential and kinetic energy, where only the kinetic energy is radiated. When traveling along a homogeneous region, the energies are more or less conserved. But, during reflections, these energies get larger and smaller and cause a fluctuation in the kinetic energy and so in the radiation of sound.
Analysis of high-amplitude jet noise using nonlinearity indicators
Authors: Gee Kent L. , Shepherd Micah R. , Falco Lauren E. , Atchley Anthony A. , Ukeiley Lawrence S. , Jansen Bernard J.
Published: October 2013

Nonlinear effects in high-amplitude jet noise are often characterized by examining spectral changes over some propagation range. However, in the case of typical laboratory-based measurements with model-scale nozzles, the study of nonlinearity via spectral changes is made difficult by both limited measurement bandwidth and short propagation distances. One analysis technique that potentially can overcome these difficulties is a single-point measurement of nonlinearity that has been studied most recently by Falco et al. [J. Acoust. Soc. Am. 117, 2596 (2005)]. Another potential solution is bispectral analysis, which has been used in the past as an indicator of nonlinearity for a wide variety of applications. Both of these analysis methods have been applied to data from recent laboratory measurements at the National Center for Physical Acoustics. Observed trends for a variety of source conditions, measurement angles, and propagation distances are discussed. [Work supported in part by the Office of Naval Research.]
Predicting acoustic and seismic pulses from outdoor explosions
Authors: Attenborough Keith , Boulanger Patrice , Albert Donald
Published: October 2013

To support the formulation of a simple model that can be used for assessment and prediction of ground vibration levels due to above-ground explosions, a fast field program for layered air ground systems (FFLAGS), developed originally for continuous sound sources, has been extended to enable predictions of propagation from impulsive sound sources in a refracting atmosphere above layered porous and elastic ground. Using a mixture of measured and best-fit parameters, the pulse version of the code (PFFLAGS) has been found to give predictions of the air pressure spectrum above ground and the vertical component of solid particle velocity near the ground surface that compare tolerably well with published data for the spectra and waveforms of acoustic and seismic pulses at short range (60 m) in grass- and snow-covered ground and at longer range (3 km) in forested terrain. The predicted seismic pulses in the presence of the snow cover explain a phenomenon frequently observed for shallow snow covers whereby a high-frequency ground vibration is modulated by a lower-frequency layer resonance [Work supported in part by SERDP SEED Project SI-1410 and Contract Number W90C2K9887EN010001 through the European Research Office of the U.S. Army.]
A ray/diffraction model of high-frequency backscattering for the study of caustic merging in simple targets
Authors: Dzikowicz Benjamin R.
Published: October 2013

The backscattering from certain finite geometric targets can be enhanced due to caustic merging when a geometric parameter, such as aspect, is varied. For example, Blonigen and Marston [Blonigen & Marston, ‘‘Backscattering enhancements for tilted solid plastic cylinders in water due to the caustic merging transition: Observations and theory,’’ J. Acoust. Soc. Am. 107, 689–698 (2000)] have shown that there occurs an enhancement for doubly reflected shear waves within a finite plastic cylinder at certain tilt angles. Here, the contributions of single ray classes, such as the doubly reflected shear waves in the example above, are numerically summed by following ray patches on an incoming reference plane through the target and back, forming a patch on an outgoing diffraction plane. The phase and magnitude of the returning patch depend on reflection and refraction coefficients and attenuation in the target material. When integrated, these patches can form singularities when rays merge at the screen and the patch sizes become infinitesimal. To solve this problem, a change in variables is made and the integration performed over the incoming, rather than the outgoing, patches. By studying the contribution of a single class of rays, individual caustic merging transitions can be studied. The total scattering at steady state can be written as an infinite sum of all classes of rays. [Work supported by ONR.]
Determination of effective properties and effective thickness of resonant acoustic metamaterial
Authors: Fokin Vladimir , Ambati Muralidhar , Sun Cheng , Zhang Xiang
Published: October 2013

Multiple scattering in periodic structures with strong modulation of elastic constants leads to phononic band structures. According to the Bragg’s theory, the spatial modulation of the periodic structure must be of the same order as the wavelength of considered elastic waves. A resonant acoustic metamaterial’s respective wavelength is about two orders of magnitude larger than the lattice constant. Each unit cell consists of a locally resonant structural unit in contrast to simple acoustic scatterers in phononic crystals. In this report, we will address the design of locally resonant sonic materials. These materials may offer dynamic effective negative material properties around resonance frequency. Locally resonant sonic crystals, such as an array of Helmholtz resonators and cylinders or spheres coated with acoustically soft material, were analyzed in the literature. However, existing literature lacks a systematic study of the dependence of effective properties for a finite slab of these metamaterials both on the geometry and the properties of its constituent materials. In this report, we present a method for obtaining effective properties and effective thickness of a slab of acoustic metamaterial. The dependence of effective acoustic properties of a metamaterial on the geometrical and acoustic properties of constituent materials will be discussed.
Perturbation theory of resonance amplification for skewed fan blades
Authors: Martinez R. , Stokes A.
Published: October 2013

The vibrational response of generic turbomachinery blades has been analyzed via a Timoshenko-Mindlin theory of flexure for thick beams formally extended to include torsion due to 3D skew. An alternate interpretation is the generalization of the governing equations of the special case of a radially stiff rib of prismatic cross section to include thick-beam flexure for displacements in the axial direction. The development identifies an artificially small parameter for the coupling of bending and torsion. A subsequent perturbation analysis yields an expression for the system’s resonance-amplification envelope in terms of its material loss factor and flexural modal density as affected by torsion. The asymptotic theory reveals how a blade’s skew could be exploited to transfer vibrational energy from flexure to torsion and thereby maximize a turbomachine’s overall damping for bending. The greatest benefits are found for a band of high frequencies straddling the point at which the dispersive phase speed for thick flexure matches the prismatic member’s effective torsional wave speed. Comparisons are made between the closed-form predictions of the perturbation analysis and exact calculations that do not rely on a presumed smallness of the coupling between flexure and torsion.
Detecting and classifying adhesive flaws between bonded elastic plate: The inverse problem
Authors: Leiderman Ricardo , Barbone Paul E.
Published: October 2013

A time-harmonic inverse scattering problem to reconstruct the effective stiffness distribution of an adhesive bond in a layered elastic plate was formulated and solved. The motivation is based on the assumption that localized adhesion flaws that diminish bond stiffness also tend to diminish bond strength. The formulation and solution are based on the invariant embedding method, apply to isotropic and anisotropic elastic layers, and are essentially that of identifying embedded acoustic sources in elastic layered structures. Two solutions of the inverse problem are presented: the Born approximation and the exact solution. In the example calculations we compare the two solutions and show that when imperfections are too large the accuracy of the Born approximation breaks down. The impact of noise and uncertainties in the background properties in the inversion is also investigated.
The hybrid system of voice onset time in French/English bilinguals
Authors: Gurski Claire
Published: October 2013

This study will look at the production of occlusive consonants by bilinguals in both their first and second languages, namely French and English. Due to the inherent differences in the voice onset times (VOTs) of these two languages, do second language speakers acquire a native-like voice onset time when speaking in their second language or do traces of their first language remain? It will be shown that although French and English have categorical distinctions in their VOT systems [Keating ‘‘Phonetic and phonological representation of stop consonant voicing,’’ Language, 60, 286–319 (1984) Lisker & Abramson, ‘‘A cross-language study of voicing in initial stops: Acoustic measurements,’’ Word. 20, 384–422 (1964)] a hybrid system of the two languages is produced regardless of first language. This research is part of a larger continuing study looking at speaker identification of bilinguals. Due to the right to a trial in either of the official languages of Canada, French or English, it is impossible to force a bilingual suspect to supply a voice sample that can be compared with an incriminating recording in one of the two languages. In such a situation, is it possible to base an identification (or a nonidentification) on the comparison of samples in the two languages of the suspect?
Vowel imitation of 4-year-old children
Authors: McGowan Richard S.
Published: October 2013

Published formant scalings for vowels of American 4-year-olds who were imitating adult production are used along with published data of American adult male vowel production to synthesize /ah, ae, uu, ii/. Perturbations to these vowels were also synthesized. Adult listeners were asked to categorize these synthetic vowels in a forced-choice task. Except for a preference for slightly more extreme first formant frequencies and higher second formant for /ae/, the formant frequencies preferred for the vowels /ah, ae, uu, ii/ were close to the values used for synthesis. A five-tube model was used in an algorithm to infer vocal-tract shape from the first three formant frequencies of the adult productions, the children’s synthesized /ah, ae, uu, ii/, and the formant frequencies derived for these vowels based on the listening experiments. It was found that the rear tube length for the children, in proportionate terms, was nearly always greater than that of the adult. In proportionate terms the rear tube length was twice as long in children compared to adults for the vowel /uu/. Tongue root flexibility may be more important than pharynx length in determining formant scalings for young children. [Work supported by NIHD-003782 to Haskins Laboratories.]
Perception and cognition of acoustic signals
Authors: Heller Laurie M.
Published: October 2013

Sonar operators may distinguish the sound of a submarine from the sound of a fishing trawler amidst a background of snapping shrimp. This accomplishment requires integrating auditory sensation and perception with auditory cognition, experience, and the ability to adapt to context. The fundamentals of auditory perception and cognition required for this task will be reviewed in this talk. I will cover a range of levels in the auditory system: from the ability to detect a signal in a background of noise, to the ability to distinguish a complex pattern from a complex background, to the ability to analyze the physical properties of an event. This review of both empirical data and research will cover a variety of psychoacoustic testing methods that is appropriate for different situations that are likely to be encountered in underwater signal processing, such as detection, discrimination, and identification.
The coupled oceanographic-tomographic analysis and prediction system: A practical means for utilizing high-frequency tomography in the world’s oceans
Authors: Stein Peter J. , Lewis James K. , Rajan Subramaniam D.
Published: October 2013

Over the last several years, technology has been developed to transition ocean tomography out of the laboratory and into practical use. This technology, the coupled oceanographic-tomographic analysis and prediction system (COTAPS), couples an ocean circulation model in a region with travel time information from a network of high-frequency acoustic nodes in the same region. A data assimilation technique is used to impose corrections to the ocean model temperatures and salinities based on observed arrival time anomalies and a Kalman gain matrix. Details of the features of COTAPS are presented and discussed. This includes the technique and associated software for assessing ray path information in the area in which the network of nodes is deployed, an automated method for calculating the Kalman gain, and a suggested design of the acoustic nodes. We also discuss a few issues that remain to be researched. These include significant variability of observed arrival times over short time intervals (less than 5 min) and how to mitigate the impact of such variability, the use of observed arrival times to account for errors in the locations of the nodes in a network, and the effect of assimilating arrival time information from multiple source-receiver pairs.
Subjective and objective evaluation of air-conditioning noise
Authors: Jeon Jin Yong , You Jin , Kim Su Yeon
Published: October 2013

Noise from an air-conditioning system installed in the ceiling of classrooms was evaluated to investigate the subjective responses to air-conditioning noise. Harmonics of air-conditioning noise was removed and the sound-pressure levels of the frequency bands from 250 to 630 Hz were varied to control sound quality. Evaluation for air-conditioning noise sensation was conducted using a paired comparison method and the results showed that noise without harmonics was preferred to noise with harmonics. The noises which have larger level increases to the noise at 250 to 630 Hz were evaluated better in both of the noises with and without harmonics. Results of multiple regression analysis on psychoacoustic parameters and subjective preferences showed sharpness as a major factor in describing the sound quality of air-conditioning noise. A semantic differential test was also conducted to evaluate the sound-quality characteristics of air-conditioning noise.
An approximate method for the computation of the response of a line-driven, fluid-loaded plate with edges
Authors: DiPerna Daniel , DiPerna Xingguang
Published: October 2013

An approximate method for predicting the response of a line-driven, fluid-loaded plate will be presented. The method is based on the free space Green’s function using the rational function approximation developed by DiPerna and Feit. The approximte representations of the Green’s function and pressure and velocity fields will be shown to satisfy the Helmholtz integral equation for the infinite plate. The Helmholtz integral equation will then be used in conjunction with these approximate representations to solve the problem of a finit length plate. Results from the approximate solution will be compared to results from finite-element analysis.
Developmental changes in the acoustic vowel space of Mandarin-learning children before 2 years of age
Authors: Chen Li-mei
Published: October 2013

Vocalic productions of Mandarin-learning infants aged 0–24 months were audiotaped and analyzed. Major findings in this longitudinal study are (1) There is no obvious change in the range of F1 and F2 values during these 2 years; (2) Midcentral vowels occurs most frequently for infants younger than 6 months. Vowel /a/occurs most frequently in infants 7 to 24 months old; (3) The frequently occurring vowel categories show steadier pattern of vowel formant frequencies in the second year; (4) Other vowels develop rapidly from 18 months on. However, the newly developed /i, u/ are difficult to identify because of the low amplitude and short duration at this stage of development; (5) Diphthongs, triphthongs, and vowels with nasal endings appear. However, they are unstable, weak, abrupt, and incomplete in the transition. These cause great difficulty in perceptual judgment and acoustic analysis. (6) The individual differences found in the first year became less obvious in the second year. [Investigation supported through funds from National Science Council in Taiwan, Republic of China (NSC 90-2411-H-006-015) (NSC 92-2411-H-006-021) (NSC 93-2411-H-006-024) and a faculty grant from National Cheng Kung University.]
Sequential contrast versus compensation for coarticulation in Japanese versus English
Authors: Mash Daniel , Kawahara Shigeto
Published: October 2013

English listeners identify a stop ambiguous between /t/ and /k/ more often as ‘‘k’’ after [s] than after [sh] (Mann and Repp, J. Acous. Soc. Am. 69, 548–558, 1981). This bias could reflect compensation for coarticulation, which undoes the fronting of a stop expected next to [s], or instead sequential contrast, in which an intermediate F3 value sounds lower and more ‘‘k’’-like after [s]’s high-frequency energy concentration. Japanese may distinguish these accounts’ predictions. The Japanese sibilant fricative is pronounced [s] before [u] but [sh] before [i]. These vowels delete between two voiceless consonants, so [s] or [sh] can occur before [t] or [k] in surface forms. If Japanese listeners treat [s] followed by a stop from a [t-k] continuum as containing an intervening [u] and [sh]-[t-k] as containing an intervening [i], sequential contrast but not compensation for coarticulation predicts that they should identify more of the continuum as ‘‘t’’ after [s] because [u] concentrates energy at lower frequencies than [i]. However, if they instead judge the stop in terms of the fricative that occurs next to it on the surface, then they should respond like English listeners, and their behavior is predicted equally well by sequential constrast and compensation for coarticulation. [Work supported by NIH.]
Estimating mutual information for the underwater acoustic channel
Authors: Gendron Paul
Published: October 2013

Estimates of the upper and lower bounds on the information rates attainable for acoustic communication systems with white Gaussian sources under uncertain channel conditions are provided that account for finite duration signaling and finite coherence time. For the case where the coherence time of the channel exceeds that of the packet duration the estimators are computationally efficient with the Levinson recursion and provide a means of tuning the accuracy of the estimates to fit a given computational budget. The reduction in the information rate relative to the known channel case is quantified in terms associated with the duration of signaling, the posterior covariance of the channel, and the prior covariance of the channel. For scenarios where the prior channel covariance is known exact bounds on the information rates are computable else the estimators provide confidence intervals for these rates. The estimators are tested on 18 kHz at sea data collected in shallow water north of Elba Italy on a 1.8-m aperture vertical array and on very shallow water sites at Keyport Washington. The effects of temporal coherence degradation as well as multi-path spread are quantified. [Work supported by the Office of Naval Research.]
Is all hearing cochlear?—revisited (again)
Authors: Todd Neil P. McAngus
Published: October 2013

Over 70 years ago John Tait raised a question with regards to the certainty that the line of division between the hearing and vestibular portions of the VIIIth cranial nerve had been drawn at the proper place [J. Tait, Ann. Otol. Rhinol. Laryngol. 41, 681–704 (1932)]. His reason for raising this question was the evidence which existed at that time that the otolith organs of anamniotes (fish and amphibians), most commonly the sacculus, were demonstrably organs of hearing in many species. He went on to speculate about a possible auditory role for the otolith organs in amniotes (reptiles, birds, and mammals), including in humans, although at this time there was no direct evidence for this. Since this time, however, there has developed a significant literature documenting evidence, not only for anamniote otolithic hearing, but also for a conserved acoustic sensitivity for the amniote otoliths. In the case of humans, this sensitivity has been exploited for the development of new acoustic tests of vestibular function. The time is ripe 70 years on, therefore, for us to revisit John Tait’s question and explore the possibility that the sacculus may indeed contribute to human hearing. [Work supported by the Royal Society.]
Saccular hearing in anurans
Authors: Horowitz Seth S. , Simmons Andrea M.
Published: October 2013

Acoustic sensing in anurans is mediated by several inner ear organs, including the amphibian papilla, basillar papilla, and lagena. The contribution of the saccule to hearing in adult ranids tends to be constrained to vibration sensitivity and gravity sensing, although there has been some evidence for low-frequency hearing sensitivity as well. The organs that mediate hearing in larval ranids are less well understood. Several studies have postulated a strong role for saccular-mediated hearing in tadpoles, operating by the sensing of particle motion mediated by direct kinetic effects on otolithic organs (the fenestral pathway). Physiological studies show that, in tadpoles, the medial and lateral vestibular nuclei are sensitive to particle motion stimulation, while the dorsal medullary nucleus is more sensitive to pressure stimulation. Anatomical tract tracing with lipophilic cyanocarbanine dyes placed in the saccular branch of the eighth nerve show projections to both auditory and vestibular medullary nuclei, suggesting that input from the saccule may play a role in both particle and pressure sensation.
Saccular hearing; turtle model for a human prosthesis
Authors: Lenhardt Martin L.
Published: October 2013

The saccule is a hearing organ is some vertebrates thought to be responsive to substrate vibration (bone conduction) or low-frequency aerial sound. There was likely some overlap in these functions in the course of evolution after the sensory area to become the cochlea migrated from the saccule. That overlap is preserved in extant turtles by columella (stapes) saccular coupling via fibroelastic strands; thus both organs can respond to air conduction and bone conduction stimulation. Evoked potential data, however, reflect differential AC/BC drive to the inner ear. The columellas inertia provides the force to displace the saccular wall with the tympanum providing damping. Intense AC stimulation likely stimulates the human saccule. A proprietary stapedial saccular strut is described that serves as a surgically implanted coupling device for humans, allowing more efficient use of AC saccular hearing in clinical deafness. The human saccular resonance is about 350 Hz, which should allow for sufficient speech coding for intelligibility assuming connectivity to the auditory neuraxis. BC stimulation through audible ultrasound also likely activates the saccule in individuals with profound deafness. A stand-alone stapedio-saccular strut or one used in combination with an ultrasonic hearing aid offers the potential of communication through saccular hearing.
Integrated marine mammal monitoring and protection system: Gray whale target strength measurements
Authors: Lucifredi Irena , Vandiver Amy , Stein Peter
Published: October 2013

With a broader objective of establishing a global solution for systematic assessment and protection of the marine environment, one of the central objectives of this work is to distinguish whale backscattered responses from the ones generated by the environmental clutter in a waveguide. Furthermore, it aims to identify and analyze the target signature features that are necessary for enhanced active sonar detection and classification of marine mammals. Over the years there have been very few documented attempts to capture and analyze the backscattering response of whales using an active sonar system. Nevertheless, whales, mostly owing to their size, their motion, and the aspect dependence of their backscattered field, possess desirable properties that help distinguish their scattered response from clutter and other environment related false alarms. As an initial step, data collected during the Marine Mammal Active Sonar Test (MAST04) is presented, and long-range gray whale target strength measurements are obtained. Results are compared to the previously published whale target strengths. Additionally, an investigation is conducted in an effort to provide whale feature identification points suitable for automated detection and classification, as a means of relating gray whale active acoustic signatures to their inherent characteristics and motion. [Work supported by ONR.]
Initial application of spectrogram-based cross correlation to the localization of Orcas
Authors: Renken Martin C.
Published: October 2013

Localization and tracking of sperm whales (Physeter macrocephalus) and pilot whales (Globicephala macrorhynchus) has been demonstrated using the widely spaced bottom-mounted hydrophone arrays located at the Atlantic Undersea Testing and Evaluation Center (AUTEC), Andros Island, Bahamas [Moretti et al., US Navy J. Und. Acoustics 52, 651–668 (2002)]. The marine mammal monitoring utilizes a cross correlation of the spectrogram calculated from acoustic calls received at each hydrophone. The spectrogram information is combined with time of arrival pattern estimates to identify specific animals in order to estimate the animal’s position through triangulation. This paper explores the initial application of these techniques to the wide variety of acoustic vocalizations recorded from transient killer whales (Orcinus Orca) in Dabob Bay of Washington state’s inland waters in February of 2005. The recordings were made from a bottom-mounted linear array of hydrophones during a period of low acoustic interference. While this recording was obtained by Naval Undersea Warfare Center Keyport, active operations are not conducted in the presence of whales according to standard operating policy. Monitoring in the Dabob Bay Naval Operating Area is carried out both visually and acoustically by range operators trained in marine mammal identification by NOAA.
Physics-based volume clutter from GeoClutter biological distributions
Authors: Frankel Adam , Love Richard H. , Monjo Charles , Newhall Bruce , Arvelo Juan I. , Ellison William T.
Published: October 2013

Empirical fish species composition and distribution data obtained during a GeoClutter survey were input into scattering models for marine mammals [Love, J. Acoust. Soc. Am. 49, 816–823 (1971)] and for schools of fish [Feuillade et al., J. Acoust. Soc. Am. 99, 196–208 (1996)]. These scattering models drew additional inputs from a database of biological parameters to generate volume clutter simulations. Model inputs included distribution of fish size, school population size, depth, orientation, and location. The volume clutter model treated each fish school and individual marine mammal as discrete acoustic targets. Motion of the dominant marine organisms (in addition to source and receiver motion) was taken into account to observe clutter map variability during a series of pings. The volume clutter distribution from this physics-based approach was compared against bottom clutter and against measured clutter-rich reverberation from the GeoClutter experiment. [The Office of Naval Research (ONR) is sponsoring this effort.]
Local versus distal speaking-rate normalization effects
Authors: Winn Matthew , Newman Rochelle
Published: October 2013

Individuals vary their speaking rate, and listeners typically use the speaking rate of precursor sentences to adjust for these changes (Kidd, 1989). This study examines the temporal window over which these effects occur, by comparing the size of rate normalization effects for local, distal + local, and global rate changes in a precursor phrase. A single talker produced the precursor sentence ‘‘Sarah brought a bag so Paul could get the —’’ at three different speaking rates, followed by a final word containing a duration-based contrast (bin versus pin). Listeners heard trials in which either the whole precursor sentence was spoken at a fast, medium, or slow rate, or (via cross-splicing) only portions of the sentence varied in rate. Subjects rated the target phoneme in the final word as either a ‘‘b’’ or a ‘‘p’’ using a six-step rating scale. Local rate changes (changes in the speaking rate of ‘‘get the’’) yielded significant normalization effects, seen as the shifting of the VOT boundary between p and b. The addition of distal rate changes, however, yielded no significant changes in perception on top of this local effect. This is in contrast to earlier work supporting two separate (local and distal) effects of rate changes.
On the relation of apparent naturalness to phonetic perceptual identification of voicing
Authors: Remez Robert E. , Landau Claire , Ferro Daria F.
Published: October 2013

Does the qualitative experience of speech sounds influence phonetic perception? Our studies of consonant place perception have revealed a dichotomous relation between phonetic sensitivity and naturalness. Although natural quality and phonetic sensitivity sometimes co-vary, in other conditions phonetic sensitivity is indifferent to huge variation in naturalness. New tests are reported here extending the research to the dimension of voicing, a contrast correlated with qualitatively distinct acoustic constituents in normal production. Two acoustic methods were used to create naturalness variants: (1) variation in the excitation of a synthetic voicing source and (2) variation in the bandwidth of the formant centers. A naturalness tournament was composed of items drawn from the test series, and the sensitivity of perceivers to the voicing contrast was estimated with the cumulative d′ across the series in identification tests. Together, the findings show how intelligibility and naturalness can be either orthogonal or contingent aspects of consonant perception for the dimensions of place and voicing. These measures offer a tool to understand the contribution of normative functions in the perception of speech. [Research supported by NIH (DC00308).]
Dispersion and attenuation due to scattering from heterogeneities in the frame bulk modulus of sand sediments
Authors: Hefner Brian T. , Jackson Darrell R.
Published: October 2013

A model that predicts the sound speed and attenuation of Biot fast compressional waves when there is scattering into the slow compressional wave has been developed. The scattering is due to small scale heterogeneities in the sediment properties such as the porosity or the bulk modulus of the frame that arise due to the random packing of the sediment grains. This model may account for the deviation of measured fast wave attenuation from the predictions of Biot theory that have been observed in both ocean and laboratory sediments. To compare the predictions of this theory with sound speed and attenuation measurements, the spatial statistics of the sediment properties must be known. Despite work in the granular physics community to understand the distribution of the contact forces between the grains, no direct measurements have been made on the spatial variations in the bulk modulus for dry or fluid-saturated sediments. In order to estimate these variations, we have performed molecular dynamics simulations of spherical bead packs which may approximate simple glass bead sediments. The progress of these simulations and the techniques used to estimate the bulk modulus on scales approaching the grain diameter will be presented. [This work is supported by ONR.]
Green’s function retrieval through ocean acoustic interferometry
Authors: Brooks Laura A. , Gerstoft Peter
Published: October 2013

A stationary phase argument is used to describe the relationship between the stacked cross-correlations from a line of vertical sources, located in the same vertical plane as two receivers, and the Green’s function between said receivers. Results and simulations which demonstrate the approach and are in agreement with those of a modal based approach used by others are presented. Results indicate that the stacked cross-correlations can be directly related to the shaded Green’s function, so long as the modal continuum of any sediment layers is negligible. Preliminary results from the SWO6 experiments are discussed. [Work supported by ONR, Fulbright (sponsored by Clough Engineering), and DSTO Australia.] a)Also at the School of Mechanical Engineering, University of Adelaide, Australia.
Applications of seismic interferometry to seismic field data
Authors: Snieder Roel , Mehta Kurang , Miyazawa Masatoshi , Vasconcelos Ivan , Sheiman Jon , Calvert Rodney , Bakulin Andrey , Venkataraman Anupama
Published: October 2013

In seismic interferometry one extracts the Green’s function of a system from fluctuations in the system. This makes it possible to retrieve the waves that propagate between receivers, as if one of the receivers acts as a source. Examples are presented of this principle to field data. One can show that in seismic interferometry one can retrieve the Green’s function that has different boundary conditions than the physical system has. It is shown how this can be used to unravel the building response from its coupling to the subsurface, and how this principle can be exploited to suppress surface-related multiples in marine seismics. As another example, we present the propagation of P-wave and S-waves down a vertical borehole extracted from incoherent man-made noise, and how shear-wave splitting can be extracted from these measurements. Finally we show how drill-bit noise can be used for imaging when the vibrations in the drill stem have not been recorded.
Detecting and identifying non-stationary signals
Authors: Williams Duncan P. , Catherall Aled T.
Published: October 2013

Detecting and identifying non-stationary signals is well known to be important in many sonar applications. While great strides have been made in the last 60 years of underwater sonar, every effort is still needed to detect and then identify whatever glimpses in the ocean can be found. The traditional method for analyzing such signals, which contain time-varying frequencies, is the short-time Fourier transform (STFT) or lofargram. However, neither the STFT nor other methods, such as wavelet transforms and Wigner-Ville distributions, that have found favor in speech processing, are always well-suited to non-stationary signals. The story remains the same out of the water too. The fractional Fourier transform (FrFT) has emerged in recent years as a powerful tool for analyzing complicated non-stationary signals. As an example, we first apply the FrFT, alongside other time-frequency methods, to examine real bat chirps, marine mammal soundings, and speech signals. A new short-time FrFT, which accounts for signals with multiple non-stationary components, is then demonstrated, allowing us the flexibility to track several different signals at the same time. The remainder of the paper outlines some of the classification techniques, which complement the output from the short-time FrFT, trying to identify non-stationary signals of every kind.
Modeling the detection of interaural incoherence
Authors: Goupell Matthew J. , Hartmann William M.
Published: October 2013

Several hundred reproducible noises, with interaural coherence slightly less than 1.0, were used in psychoacoustical experiments intended to discover how listeners detect small amounts of interaural incoherence in narrow-band noise stimuli. The most successful detection model, which correlated with the detection data at r=0.87, employed independent encoding of compressed (exponentially saturating) interaural phase fluctuations (IPF) and compressed interaural level fluctuations (ILF). Fluctuations were recombined centrally such that 5 degrees of IPF (28 μs of ITD) were equivalent to 1 dB of ILF. Integration times were found to be less than 10 ms, indicating that binaural sluggishness played no role. Neurophysiologically motivated short-term cross-correlation models (including auditory filtering, parameterized cochlear compression of the envelope, half-wave rectification, and temporal integration) were somewhat less successful in that they led to r values that were never greater than 0.78. Models were tested in step-by-step calculations to quantify the consequences of the various components of the models. [Work supported by the NIDCD of the NIH, Grant DC-00181.]
Interaction of an inhomogeneous acoustic plane wave with a fluid sphere: Analytical solution
Authors: Foote Kenneth G.
Published: October 2013

The problem of scattering of a plane acoustic wave by a fluid sphere was addressed by V. C. Anderson [J. Acoust. Soc. Am. 22, 426 (1950)]. This wave was assumed to be homogeneous, without amplitude variation over the wave front. The problem of scattering of a plane wave partially insonifying a rigid sphere was addressed by G. C. Gaunaurd [IEEE J. Oceanic Eng. 10, 213 (1985)], but in the Kirchhoff approximation. Here, the problem of scattering of an inhomogeneous plane acoustic wave by a fluid sphere is addressed. A general analytical solution is given. A particular solution is described for a monochromatic plane wave whose amplitude on the surface of a sphere of radius r=a, with center at the origin, is exp[ika cos θ−2αa cos2(θ/2)], where k is the wavenumber, θ is measured relative to the direction of propagation, and α is the absorption coefficient. Both the scattered and internal fields are evaluated for a range of parameter values of k, α, r, and θ, and compared against the Anderson solution for a homogeneous plane wave. It is believed that H. Medwin would have appreciated the unexpressed direction of this work: modeling of sonar interactions with marine animals.
Pitch discrimination interference: Monaural and binaural pitches
Authors: Gockel Hedwig E. , Carlyon Robert P. , Plack Christopher J.
Published: October 2013

Fundamental frequency (F0) discrimination between two sequentially presented complex (target) tones can be impaired in the presence of an additional complex tone (the interferer) filtered into a remote spectral region [H. Gockel, R. P. Carlyon, and C. J. Plack, J. Acoust. Soc. Am. 116, 1092–1104 (2004)]. This pitch discrimination interference (PDI) is greatest when the interferer and target have similar F0s. Here, PDI was measured using monaural or diotic complex-tone interferers and Huggins pitch or diotic complex-tone targets. We first showed that listeners hear a complex Huggins pitch (CHP), approximately corresponding to F0, when multiple phase transitions at harmonics of (but not at) F0 are present. The accuracy of pitch matches to the CHP was similar to that for an equally loud diotic tone complex presented in noise. Similar amounts of PDI were observed for CHP-targets and for loudness-matched diotic complex-tone tone targets. Thus, PDI can occur between stimuli that initially are processed in a different way, making it unlikely that PDI occurs at a very peripheral stage of auditory processing. A corollary is that conventional complex tone and Huggins pitches appear to be processed in common at the stage where PDI occurs. [Work supported by EPSRC Grant EP/D501571/1.]
Apfel’s apples: A generation of scientists trained at Yale
Authors: Ketterling Jeffrey A.
Published: October 2013

Bob Apfel taught at Yale University for over thirty years, advising scores of students during that time. Prior to Yale, Bob trained at Harvard University with Frederick Hunt and the chain of advisors can be loosely traced back, all at Harvard, to 1802. During his time at Yale, Bob graduated 28 Ph.D.’s and trained 12 post-doctoral students in addition to the numerous undergraduates that he advised. Many of the students moved on to become professors themselves and, following the lead of Bob, many are very active in the Acoustical Society of America.