bluuebunny/crossref_metadata_2025 huggingface dataset:
Segment sequencing and the jaw cycle
Authors: Redford Melissa , van Donkelaar Paul
Published: September 2013

The open–close jaw cycle established in running speech often spans the articulation of several segments. Moreover, the extremes of the cycle are associated with opposing segment types, consonants and vowels, which form higher-level linguistic units, syllables, when grouped. The present study sought to determine how the syllable is related to the cycle. A partial relationship may imply that the jaw moves linearly from one segment to another. An isomorphic relationship that jaw movement is planned over the articulation of a group of segments, regardless of segment sequencing within the group. Five speakers repeated one of five syllable types (CV, VC, CVC, CCV, VCC) continuously for several seconds, producing an unbroken sequence of consonants and vowels. Jaw movement and acoustic data were recorded simultaneously and used to determine the temporal boundaries of the cycles and syllables, respectively. Cycle boundaries were defined by the points of maximum closure preceding and following an opening gesture, and syllable boundaries according to changes in frequency and amplitude corresponding to the onset of the initial and final segments in the syllable. A comparison of the relative boundary locations suggested an isomorphic relationship between cycles and syllables that interacted with segment type, syllable shape, and speaker.
The role of standards in noise
Authors: Peppin Richard J.
Published: September 2013

This paper discusses how the noise community uses standards. The noise community consists of people working in the control and abatement of noise sources: produced by, or isolated as a result of, mechanical, information, transportation, vehicle, highway, industrial, and building systems. For the purposes of this paper, standards are described as ‘‘agreed upon ways of doing things.’’ Many of the standards available, their organizations, and their interrelationships will be addressed. The presentation will show how the various disciplines are concerned with the different groupings of standards and why, in many instances, it is impossible to do work without them.
The application of standard definitions of sound to the fields of underwater acoustics and acoustical oceanography
Authors: Carey William M.
Published: September 2013

Recent societal concerns have focused attention on the use of sound as a probe to investigate the oceans and its use in naval sonar applications. The concern is the impact the use of sound may have on marine mammals and fishes. The focus has changed the fields of acoustical oceanography (AO) and underwater acoustics (UW) because of the requirement to communicate between disciplines. Multiple National Research Council publications, Dept. of Navy reports, and several monographs have been written on this subject, and each reveals the importance as well as the misapplication of ASA standards. The ANSI-ASA standards are comprehensive, however not widely applied. The clear definition of standards and recommendations of their use is needed for both scientists and government agencies. Traditionally the U.S. Navy has been responsible for UW standards and calibration; the ANSI-ASA standards have been essential. However, recent changes in the Navy and its laboratory structure may necessitate a more formal recognition of ANSI-ASA standards and perhaps incorporation of UW-AO in the Bureau of Standards. A separate standard for acoustical terminology, reference levels, and notation used in the UW-AO is required. Since the problem is global, a standard should be compatible and cross referenced with the International Standard (CEI/IEC 27-3).
The control of balance between singer on the stage and orchestra in the pit by means of virtual opera house models
Authors: Parati Linda , Pompoli Roberto , Prodi Nicola
Published: September 2013

In this study some of the architectural elements which can influence the balance between the singer on the stage and the orchestra in the pit, in respect to the design constraints, have been investigated. By means of room simulations, modifications in the type of materials, dimensions, and shapes of the pit, and modifications of the proscenium dimension and stage slope were applied. Some of the architectural elements controlling the balance have been identified and optimized. Simulations were performed with omnidirectional sources in the pit, despite the directivity of the instruments, and directional source on the stage. The effects of the applied changes on the balance between singer, conductor, and orchestra have been analyzed too.
Hearing in the North Atlantic right whale: Anatomical predictions
Authors: Parks Susan E. , Ketten Darlene R. , O’Malley Jennifer Trehey , Arruda Julie
Published: September 2013

Understanding the hearing abilities of large whales is important to determine the impacts of anthropogenic sources of sound. Right whales are not amenable to traditional physiological techniques to test hearing. Previous research on the hearing of marine mammals has shown that functional morphometric models are reliable estimators of hearing sensitivity in marine species. Morphometric analyses of 18 inner ears from 13 stranded right whales were used in the development of a preliminary model of the frequency range of hearing. All ears were scanned with computerized tomography (CT). Four ears showing the best preservation were processed into slides for measurements of the basilar membrane. Calculated basilar-membrane length averaged 55.7 mm (range 50.5–61.7 mm). The ganglion cell density/mm averaged 1842 ganglion cells/mm. Membrane length and ganglion cell density were used to predict a total ganglion cell count of approximately 102500 ganglion cells for right whales. The thickness/width measurements of the basilar membrane from slides resulted in an estimated frequency range of approximately 10 Hz–22 kHz based on established marine mammal models. Additional measurements from more specimens will be necessary to develop a more robust model of the right whale hearing range. a)Currently at Cornell University Bioacoustics Research Program.
Reduced temporal integration in Belgian Waterslager canaries
Authors: Lauer Amanda M. , Dooling Robert J.
Published: September 2013

Belgian Waterslager canaries (BWS) are bred for their low-frequency song and have been shown to have hair cell abnormalities in the inner ear that result in elevated thresholds at higher frequencies. Previous results show that resolution of temporal fine structure, or the ability to resolve rapidly occurring changes in complex sounds, is enhanced in BWS canaries. In a continuing effort to assess the effects of the BWS inner ear pathology on hearing, we here investigate the ability to integrate acoustic information over longer periods of time. Absolute thresholds for 1.0-, 2.0-, and 4.0-kHz pure tones were measured in BWS and normal-hearing nonBWS canary strains for durations ranging from 5 to 480 ms using operant conditioning methods. NonBWS canaries showed a decrease in threshold of approximately 10–15 dB with increasing tone duration for all frequencies. In contrast, BWS showed almost no change in threshold across the range of durations tested for all frequencies. The reduced temporal integration in BWS canaries with hair cell abnormalities parallels similar findings in humans with cochlear damage. [Work supported by NIH DC01372 to RJD and DC05450 to AML.]
Computation of T-phase seismograms using stairsteps to model seafloor bathymetry changes
Authors: de Groot-Hedlin Catherine
Published: September 2013

Stair-step boundaries are employed to represent range-dependent seafloor bathymetry in many types of numerical modeling methods. However, if an overly coarse discretization is used to simulate smoothly varying bathymetry, the acoustic solution is degraded in a way that simulates scattering. Geometrical optics approximations can be used to derive discretization criteria for simulating a smoothly sloping interface for the case of a source embedded in either an acoustic or an elastic seafloor, and applied to modeling T phases. A finite difference time-domain modeling approach is used to synthesize T phases for both smoothly sloping and rough seafloor boundaries. It is shown that scattering at a rough seafloor boundary yields ocean-borne acoustic phases with velocities near those of observed T phase, while smooth seafloor models yield T phases with slower horizontal velocities. The long duration of the computed T phases for both the rough acoustic and elastic models is consistent with energy being scattered into the sound channel both as it transits the ocean/crust boundary, as well as at several subsequent seafloor reflections. However, comparison between the elastic and acoustic modeling solutions indicates that the T-phase wavetrain duration decreases with decreasing impedance contrast between the ocean and seafloor.
Directionality of acoustic T-phase signals from shallow submarine earthquakes
Authors: Chapman Ross
Published: September 2013

Acoustic transients radiated from shallow undersea earthquakes were studied in an experiment carried out using a towed horizontal line array operating in the South Fiji Basin. The transient signals consisted of P, S, and T phases, with the T-phase signal from each earthquake lasting for about 5 min. During this period, the directionality of the T-phase signal was determined by processing the array data with a conventional beamformer. The weakest part of the signal arrived first on a direct bearing between the earthquake source and the array. However, subsequent stronger components of the T phase arrived from different directions farther south of the source, in a region where a number of seamounts rose within the sound channel. A simple model based on ray-path travel times for p-wave travel in the earth and in the water suggests that the later components of the T-phase signal are radiated into the water by downslope propagation from the seamounts and ridges. The initial weaker components may be scattered into the sound channel by leakage from the P and S phases relatively closer to the array.
Approaches to overcome current limitations of HIFU treatment
Authors: Umemura Shin-ichiro , Kawabata Ken-ichi , Sasaki Kazuaki , Azuma Takashi , Ishida Kazunari , Kubota Jun , Ichihara Mitsuyoshi , Okai Takashi
Published: September 2013

Noninvasive therapy with HIFU has been successfully applied to transrectal treatment of prostate cancer as well as benign prostate hyperplasia. However, there are two major technical reasons why its clinical application to other organs is currently limited: (1) low throughput of treatment and (2) lack of penetration to deep tissues. To multiply the throughput, a split-focus technique, in which the focal spot is enlarged primarily in the lateral direction, was developed. An electronically variable focus array transducer was also developed to enhance the throughput. An approach to treat a large volume of uterus myoma by coagulating its feeding arteries has been studied. The tissue volume to be coagulated can be thereby reduced by orders of magnitude. The penetration and throughput can potentially be improved at the same time by delivering a microbubble agent to the target tissue. It was theoretically predicted that a microbubble agent could multiply the ultrasonic tissue absorption. The effectiveness of this approach was confirmed in animal experiments using Optison. Real-time monitoring of tissue coagulation during HIFU exposure also can enhance the throughput through preventing excess deposition of ultrasonic energy. Monitoring coagulation by imaging local displacement in tissue with ultrasound will be discussed as well.
Effect of nonlinearity on lesion formation for high-intensity focused ultrasound (HIFU) exposures
Authors: Lee Paul , Lizzi Frederic L. , Ketterling Jeffrey A. , Vecchio Christopher J.
Published: September 2013

This study examined the effects of nonlinear propagation phenomena on two types of HIFU transducers (5 MHz) being used for thermal treatments of disease. The first transducer is a 5-element annular array. The second is a transducer with a 5-strip electrode; its multilobed focused beam is designed to efficiently produce broad, paddle-shaped lesions. The beam patterns of these transducers were computed using a variety of excitation patterns for electronic focusing of the annular array and variation of lesion size for the strip-electrode transducer. A range of intensities was studied to determine how nonlinear propagation affects the beam shape, constituent frequency content, grating lobes, etc. These 3D computations used a finite-amplitude beam propagation model that combined the angular spectrum method and Burger’s equation to compute the diffraction and nonlinear effects, respectively. Computed beam patterns were compared with hydrophone measurements for each transducer. The linear and nonlinear beam patterns were used to compute the absorbed thermal dose, and the bioheat equation was evaluated to calculate 3D temperature rises and geometry of induced lesions. Computed lesion sizes and shapes were compared to in vitro lesions created by each HIFU transducer. [Work supported by NCI and NHLBI Grant 5R01 CA84588.]
Noncontact modal analysis of a pipe organ reed using airborne ultrasound stimulated vibrometry
Authors: Huber Thomas M. , Fatemi Mostafa , Kinnick Randall R. , Greenleaf James F.
Published: September 2013

The goal of this experiment was to excite and measure, in a noncontact manner, the vibrational modes of the reed from a reed organ pipe. To perform ultrasound stimulated excitation, two ultrasound beams in air of different frequencies were directed at the reed; the audio-range beat frequency between these ultrasound beams induced vibrations. The resulting vibrational deflection shapes were measured with a scanning vibrometer. The modes of any relatively small object can be studied in air using this technique. For a 36 mm by 7 mm clamped brass reed cantilever, displacements and velocites of 5 μ and 4 mm/s could be imparted at the fundamental frequency of 145 Hz. Using the same ultrasound transducer, excitation across the entire range of audio frequencies was obtained, which was not possible using audio excitation with a speaker. Since the beam was focused on the reed, ultrasound stimulated excitation eliminated background effects observed during mechanical shaker excitation, such as vibrations of clamps and supports. We will discuss the results obtained using single, dual, and confocal ultrasound transducers in AM and unmodulated CW modes, along with results obtained using a mechanical shaker and audio excitation using a speaker.
Tuning and rotating nearly degenerate modes in handbells
Authors: Buschert John R. , Springer Jennifer L.
Published: September 2013

We have studied nearly degenerate pairs of vibrational modes in a C4 handbell. Manufacturers seek to eliminate the beating of these modes by careful choice of the clapper position but this can’t always be done satisfactorily. Using electronic holography, we are studying the effects of small, localized mass changes on the frequency and orientation of these mode pairs. One expects one mode of the pair to rotate until it has an anti-node at the point of the added mass and the other to rotate until it has a node there. Then adding further mass should only change the frequency of the first mode. We find some mode pairs respond in just the expected manner but others behave more strangely. [Work supported by an NSF MRI grant.]
Acoustical studies of the American reed organ
Authors: Cottingham James P.
Published: September 2013

The reed organ enjoyed a period of great popularity in North America which reached a peak in the late 19th century, when thousands of instruments per year were manufactured and sold in the United States and Canada. Displaced by the emergence of the upright piano, the reed organ had very much fallen out of favor by 1929. In the past decade a number of acoustical investigations have been undertaken on the instrument known as the American reed organ. Observations of reed motion and velocity have been made with electronic proximity sensors and a laser vibrometer system. The variation of the frequency and amplitude of reed vibration as a function of blowing pressure has been explored in some detail and the results compared with predictions of a simple theoretical model. Measurements have been made of the spectrum of the near-field sound including the effects of changes in dimensions of the reed cell. While most treatments of free reed oscillation approximate the reed vibration as a sinusoidal oscillation of a cantilever beam in the fundamental transverse mode, recently some evidence of higher transverse modes and torsional modes of vibration have been observed.
Sensorineural hearing loss and auditory perceptual organization
Authors: Hall Joseph W. , Grose John H. , Buss Emily
Published: September 2013

This talk will consider the implications of sensorineural hearing loss for auditory perceptual organization. In everyday environments, the listener is often faced with the difficulty of processing a target sound that intermingles acoustically with one or more extraneous sounds. Under such circumstances, several auditory processes enable the complex waveforms reaching the two ears to be interpreted in terms of putative auditory objects giving rise to the target and extraneous sounds. Such processes of perceptual organization depend upon the central analysis of cues that allow distributed spectral information to be either linked together or split apart on the basis of details related to such variables as synchrony of onset/modulation, harmonic relation, rhythm, and interaural differences. Efficient perceptual organization must depend not only upon such central auditory analyses but also upon the fidelity with which the peripheral auditory system encodes the spectral and temporal characteristics of sound. We will consider the implications of sensorineural hearing loss for perceptual organization in terms of both peripheral and central auditory processes.
The probabilistic relationship between auditory stimuli and their natural sources predicts pitch
Authors: Schwartz David A , Purves Dale
Published: September 2013

The phenomenology of pitch has been difficult to rationalize and remains the subject of much debate. We here examine the hypothesis that audition generates pitch percepts by relating inherently ambiguous sound stimuli to their probable sources in the human auditory environment. A database of speech sounds, the principal source of periodic sound energy for human listeners, was compiled and the dominant periodicity of each speech sound determined. A set of synthetic test stimuli were used to assess whether the major pitch phenomena described in the literature could be explained by the probabilistic relationship between the stimuli and their probable sources (i.e., speech sounds). The phenomena tested included the perception of the missing fundamental, the pitch shift of the residue, spectral dominance and the perception of pitch strength. In each case, the conditional probability distribution of speech sound periodicities accurately predicted the pitches normally heard in response to the test stimuli. We conclude that pitch depends on an auditory process that relates inevitably ambiguous sound stimuli to their probable natural sources.
Mechanisms underlying the auditory continuity illusion
Authors: Pressnitzer Daniel , Tardieu Julien , Ragot Richard , Baillet Sylvain
Published: September 2013

This study investigates the auditory continuity illusion, combining psychophysics and magnetoencephalography. Stimuli consisted of amplitude-modulated (AM) noise interrupted by bursts of louder, unmodulated noise. Subjective judgments confirmed that the AM was perceived as continuous, a case of illusory continuity. Psychophysical measurements showed that the illusory modulation had little effect on the detection of a physical modulation, i.e., the illusory modulation produced no modulation masking. Duration discrimination thresholds for the AM noise segments, however, were elevated by the illusion. A whole-head magnetoencephalographic system was used to record brain activity when listeners attended passively to the stimuli. The AM noise produced a modulated magnetic activity, the auditory steady-state response. The illusory modulation did not produce such a response, instead, a possible neural correlate of the illusion was found in transient evoked responses. When the AM was interrupted by silence, oscillatory activity in the gamma-band range as well as slow evoked potentials were observed at each AM onset. In the case of the illusion, these neural responses were largely reduced. Both sets of results are inconsistent with a restoration of the modulation in the case of illusory continuity. Rather, they point to a role for onset-detection mechanisms in auditory scene analysis.
Dynamic response of in-vacuo elliptic cylindrical shells
Authors: Boisvert Jeffrey E. , Hayek Sabih I.
Published: September 2013

The equations of motion for the vibration of elliptic cylindrical shells of constant thickness were derived using a Galerkin approach. The elastic strain energy density used in this derivation has seven independent kinematic variables: three displacements, two thickness shear, and two thickness stretch. The resulting seven coupled algebraic equations are symmetric and positive definite. The shell has a constant thickness, h, finite length, L, and is simply supported at its ends (z=0,L), where z is the axial coordinate. The elliptic cross section is defined by the shape parameter, a, and the half-length of the major axis, l. The modal solutions are expanded in a doubly infinite series of comparison functions in terms of circular functions in the angular and axial coordinates. Damping is introduced into the shell via a complex Young’s modulus. Numerical results for the drive and transfer mobilities due to surface force excitations were obtained for several h/l and L/l ratios, and various shape parameters, including the limiting case of a simply supported cylindrical shell (a∼100). Sample mode shapes were obtained at selected resonant frequencies. [Work supported by ONR and the Navy/ASEE Summer Faculty Program.]
Coupled dynamic systems and Le Chatelier’s principle in noise control
Authors: Maidanik G. , Becker K. J.
Published: September 2013

Investigation of coupling an externally driven dynamic system—a master dynamic system—to a passive one—an adjunct dynamic system—reveals that the response of the adjunct dynamic system affects the precoupled response of the master dynamic system. The responses, in the two dynamic systems when coupled, are estimated by the stored energies (Es) and (E0), respectively. Since the adjunct dynamic system, prior to coupling, was with zero (0) stored energy, E0s=0, the precoupled stored energy (E00) in the master dynamic system is expected to be reduced to (E0) when coupling is instituted; i.e., one expects E0<E00. In this case a beneficial noise control of the master dynamic system would result from the coupling. It is argued that the change in the disposition of the stored energies as just described may not be the only change. The coupling may influence the external input power into the master dynamic system which may interfere with the expected noise control. Indeed, the coupling may influence the external input power such that the expected beneficial noise control may not materialize. Examples of these kinds of noise control reversals are cited.
Dynamics of transversely isotropic cylinders
Authors: Bhattacharyya Subrata K. , Vendhan Chiruvai P.
Published: September 2013

Studies on wave propagation in cylinders have a long history [M. J. Berliner and R. Solecki, J. Acoust. Soc. Am. 99, 1841–1853 (1996)]. Onoe et al. [J. Appl. Mech. 29, 729–734 (1962)] studied the attenuating and propagating modes of an isotropic cylindrical rod. Mirsky [J. Acoust. Soc. Am. 37, 106–1021 (1965)] presented the solution for harmonic wave propagation in a transversely isotropic (TI) cylinder in vacuo. Sinha et al. [J. Acoust. Soc. Am. 91, 1132–1143 (1992)] studied isotropic cylinders in contact with fluids employing the complex wave number solution. Bhattacharyya [Ph.D. thesis, Dept. of Ocean Eng., I.I.T. Madras (1989)] generalized Mirsky’s work to study a TI cylinder in contact with fluids. Berliner and Solecki (cited above) also presented a similar solution and applied it to strongly TI cylinders. The present article is concerned with the vibration of a TI cylinder under prescribed harmonic end loading. The problem may be viewed as the dynamic analog of the Saint-Venant problem. The forced vibration solution is facilitated by an orthogonality relation among the radial eigenfunctions corresponding to the real and complex roots of the dispersion relation [W. B. Fraser, J. Sound Vib. 43, 568–571 (1975)]. This approach can be used for the rigorous solution of finite cylinders.
VOT and the perception of voicing
Authors: Remez Robert E.
Published: September 2013

In explaining the ability to distinguish phonemes, linguists have described the dimension of voicing. Acoustic analyses have identified many correlates of the voicing contrast in initial, medial, and final consonants within syllables, and these in turn have motivated studies of the perceptual resolution of voicing. The framing conceptualization articulated by Lisker and Abramson 40 years ago in physiological, phonetic, and perceptual studies has been widely influential, and research on voicing now adopts their perspective without reservation. Their original survey included languages with two voicing categories (Dutch, Puerto Rican Spanish, Hungarian, Tamil, Cantonese, English), three voicing categories (Eastern Armenian, Thai, Korean), and four voicing categories (Hindi, Marathi). Perceptual studies inspired by this work have also ranged widely, including tests with different languages and with listeners of several species. The profound value of the analyses of Lisker and Abramson is evident in the empirical traction provided by the concept of VOT in research on the every important perceptual question about speech and language in our era. Some of these classic perceptual investigations will be reviewed. [Research supported by NIH (DC00308).]
VOT in cross language and comparative phonetics
Authors: Maddieson Ian
Published: September 2013

Since the earliest introduction of the concept of voice onset time to describe laryngeal timing in stop consonants (Lisker and Abramson, 1964), this measure has been used as a tool for discussing phonetic similarities and differences among languages. The distinction between broad categories of leading, aligned, or lagging voice onset in relation to oral release is useful across many languages. There are also more subtle effects on VOT duration, such as some concerning major consonant places of articulation and following vowel contexts which have proved to be repeated across languages. Combining these regularities allows relatively precise prediction of VOT in timing models. The VOT concept has also been extended to discussion of certain less-common classes of segments such as ejective stops, as well as to fricatives and affricates. The latter case raises interesting questions of distinguishing between frication noise and aspiration noise, and of what to take as the consonant’s release. How best to characterize laryngeal timing around the release of segments not followed by a vowel or voiced sonorant will also be considered.
VOT and hearing impairment
Authors: Lane Harlan , Perkell Joseph
Published: September 2013

When deafened adults recover some hearing after receiving a cochlear implant, numerous changes in their speech occur at both phonemic and suprasegmental levels. If a change toward normative values is observed for some phonemic parameter, it may be attributed to the restored hearing; however, it may be a by-product of a suprasegmental change. Consistent with results reported for speakers with normal hearing, Lane et al. [J. Acoust. Soc. Am. 98, 3096–3106 (1995)] observed in implant users that VOT varies approximately linearly with syllable duration. Therefore, in comparing pre- and postimplant measures of VOT in five speakers, each token’s VOT was adjusted for the change in syllable duration of that token relative to the mean syllable duration in a baseline session (called VOTc). Preimplant, the deaf speakers characteristically uttered plosives with abnormally short VOTc. With some hearing restored, four of the five lengthened VOTc. Changes in voiced plosives’ VOTc with restored hearing were correlated with changes in SPL. Some of the reliable VOTc increases that were not correlated with SPL may have been caused by auditory validation of an internal model for phoneme production. Recent studies of VOT in hearing-impaired speakers will be reviewed in this light. [Work supported by NIDCD, NIH.]
Acoustical imaging of underwater objects using the bistatic ramp response signals
Authors: Li Wei , Liu Gui-Rong , Varadan Vijay
Published: September 2013

The T-matrix methods have been successfully employed for underwater acoustical imaging techniques and the inverse analysis of acoustic scattering problems. Most inverse techniques use the backscattering signals in the acoustical far field to retrieve the shape and size information of an underwater object, such as the ramp response technique. This paper addresses a modified ramp response technique, which could be used to reconstruct the 3D image of an object for the bistatic case. This technique shows that the bistatic ramp response is proportional to the profile function of an underwater object based on the small bistatic angle assumption. The numerical examples demonstrate that the bistatic ramp response technique is still valid to obtain an excellent profile function even for the bistatic case with a fairly big bistatic angle. This bistatic ramp response technique allows us to reconstruct the 3D image of an underwater object with only one receiver.
Born approximation for scattering by evanescent waves: Comparison with exact scattering by an infinite fluid cylinder
Authors: Marston Philip L.
Published: September 2013

In some situations, evanescent waves can be an important component of the acoustic field within the sea bottom. For this reason (as well as to advance the understanding of scattering processes) it can be helpful to examine the modifications to scattering theory resulting from evanescence. Modifications to ray theory were examined in a prior approximation [P. L. Marston, J. Acoust. Soc. Am. 113, 2320 (2003)]. The new research concerns the modifications to the low-frequency Born approximation and confirmation by comparison with the exact two-dimensional scattering by a fluid cylinder. In the case of a circular cylinder having the same density as the surroundings but having a compressibility contrast with the surroundings, the Born approximation with a nonevanescent incident wave gives only monopole scattering. When the cylinder has a density contrast and the same compressibility as the surroundings the regular Born approximation gives only dipole scattering (with the dipole oriented along to the incident wavevector). In both cases when the Born approximation is modified to include the evanescence of the incident wave, an additional dipole scattering term is evident. In each case the new dipole is oriented along to the decay axis of the evanescent wave. [Research supported by ONR.]
Recovery and digitization of archival analog ocean acoustic data
Authors: Shooter Jack , Gaul Roy D.
Published: September 2013

In October 2002 the Office of Naval Research (ONR) sponsored a Convocation that reviewed the ocean acoustic studies done from 1967 to 1992 under the U.S. Navy’s Long Range Acoustic Propagation Project (LRAPP). Beginning in 1972 LRAPP fielded self-contained assemblies of vertically distributed hydrophones as part of environmental acoustic exercises in a variety of oceanic regions. Analog signals were recorded in a submerged buoy on multi-channel magnetic tape. Presentation of results from a 1975 measurements exercise in the Northeast Pacific stimulated interest in recovering and digitizing the 10-day dataset from 13 hydrophones. ONR sponsored a pilot project to demonstrate the feasibility of recovering the data and setting up digital files while preserving absolute accuracy. The original magnetic tape was sticky. It had to be heat treated and cleaned before playback. A spectrum from the original analysis for near-field passage of a ship was used to validate data recovery in the range of 10–500 Hz. A final objective is to produce calibrated time series so that the digital dataset can be made available for general use. [Work supported by ONR.]
Design of a new stage shell for the Stadthaus in Winterthur, Switzerland
Authors: Kahle Eckhard , Katz Brian F. G.
Published: September 2013

A new stage shell was installed in the Stadthaus, a 700-seat concert hall in Winterthur which was originally designed by architect Gottfried Semper. Musicians of the local symphony orchestra had been complaining about poor on-stage listening conditions in the stage house that was later added to the room. The small stage house (width 12 m, depth 7 m, height 7 m) was overly loud and reverberant. The design of the new stage shell will be presented and the acoustic results, both objective and subjective, will be presented. Comments by the musicians and audience members show that a stage shell must provide more than just efficient projection into the audience area. Absorption placed at the rear of the stage is paramount for obtaining proper orchestral balance, good on-stage hearing condition and clarity of sound.
Communication acoustics in Bell Labs
Authors: Flanagan J. L.
Published: September 2013

Communication aoustics has been a central theme in Bell Labs research since its inception. Telecommunication serves human information exchange. And, humans favor spoken language as a principal mode. The atmospheric medium typically provides the link between articulation and hearing. Creation, control and detection of sound, and the human’s facility for generation and perception are basic ingredients of telecommunication. Electronics technology of the 1920s ushered in great advances in communication at a distance, a strong economical impetus being to overcome bandwidth limitations of wireline and cable. Early research established criteria for speech transmission with high quality and intelligibility. These insights supported exploration of means for efficient transmission—obtaining the greatest amount of speech information over a given bandwidth. Transoceanic communication was initiated by undersea cables for telegraphy. But these long cables exhibited very limited bandwidth (order of few hundred Hz). The challenge of sending voice across the oceans spawned perhaps the best known speech compression technique of history—the Vocoder, which parametrized the signal for transmission in about 300 Hz bandwidth, one-tenth that required for the typical waveform channel. Quality and intelligibility were grave issues (and they still are). At the same time parametric representation offered possibilities for encryption and privacy inside a traditional voice bandwidth. Confidential conversations between Roosevelt and Churchill during World War II were carried over high-frequency radio by an encrypted vocoder system known as Sigsaly. Major engineering advances in the late 1940s and early 1950s moved telecommunications into a new regime—digital technology. These key advances were at least three: (i) new understanding of time-discrete (sampled) representation of signals, (ii) digital computation (especially binary based), and (iii) evolving capabilities in microelectronics that ultimately provided circuits of enormous complexity with low cost and power. Digital transmission (as exemplified in pulse code modulation—PCM, and its many derivatives) became a telecommunication mainstay, along with switches to control and route information in digital form. Concomitantly, storage means for digital information advanced, providing another impetus for speech compression. More and more, humans saw the need to exchange speech information with machines, as well as with other humans. Human-machine speech communication came to full stride in the early 1990s, and now has expanded to multimodal domains that begin to support enhanced naturalness, using contemporaneous sight, sound and touch signaling. Packet transmission is supplanting circuit switching, and voice and video are commonly being carried by Internet protocol.
Speech coding research at Bell Laboratories
Authors: Atal Bishnu S.
Published: September 2013

The field of speech coding is now over 70 years old. It started from the desire to transmit voice signals over telegraph cables. The availability of digital computers in the mid 1960s made it possible to test complex speech coding algorithms rapidly. The introduction of linear predictive coding (LPC) started a new era in speech coding. The fundamental philosophy of speech coding went through a major shift, resulting in a new generation of low bit rate speech coders, such as multi-pulse and code-excited LPC. The semiconductor revolution produced faster and faster DSP chips and made linear predictive coding practical. Code-excited LPC has become the method of choice for low bit rate speech coding applications and is used in most voice transmission standards for cell phones. Digital speech communication is rapidly evolving from circuit-switched to packet-switched networks to provide integrated transmission of voice, data, and video signals. The new communication environment is also moving the focus of speech coding research from compression to low cost, reliable, and secure transmission of voice signals on digital networks, and provides the motivation for creating a new class of speech coders suitable for future applications.
Determination of West Indian manatee vocalization levels and rate
Authors: Phillips Richard , Niezrecki Christopher , Beusse Diedrich
Published: September 2013

The West Indian manatee (Trichechus manatus latirostris) has become endangered partly because of a growing number of collisions with boats. A system to warn boaters of the presence of manatees, based upon the vocalizations of manatees, could potentially reduce these boat collisions. The feasibility of this warning system would depend mainly upon two factors: the rate at which manatees vocalize and the distance in which the manatees can be detected. The research presented in this paper verifies that the average vocalization rate of the West Indian manatee is approximately one to two times per 5-min period. Several different manatee vocalization recordings were broadcast to the manatees and their response was observed. It was found that during the broadcast periods, the vocalization rates for the manatees increased substantially when compared with the average vocalization rates during nonbroadcast periods. An array of four hydrophones was used while recording the manatees. This allowed for position estimation techniques to be used to determine the location of the vocalizing manatee. Knowing the position of the manatee, the source level was determined and it was found that the mean source level of the manatee vocalizations is approximately 112 dB (re:1 Pa) @ 1 m.
Fast algorithm for nonlinear acoustics and high-intensity focused ultrasound modeling
Authors: Curra Francesco P. , Kargl Steven G. , Crum Lawrence A.
Published: September 2013

The inhomogeneous characteristics of biological media and the nonlinear nature of sound propagation at high-intensity focused ultrasound (HIFU) regimes make accurate modeling of real HIFU applications a challenging task in terms of computational time and resources. A fast, dynamically adaptive time-domain method that drastically reduces these pitfalls is presented for the solution of multidimensional HIFU problems in complex geometries. The model, based on lifted interpolating second-generation wavelets in a collocation approach, consists of the coupled solution of the full-wave nonlinear equation of sound with the bioheat equation for temperature computation. It accounts for nonlinear acoustic propagation, arbitrary frequency power law for attenuation, multiple reflections, and backscattered fields. The characteristic localization of wavelets in both space and wave number domains allows for accurate simulations of strong material inhomogeneities and steep nonlinear processes at a reduced number of collocation points, while the natural multiresolution analysis of wavelets decomposition introduces automatic grid refinement in regions where localized structures are present. Compared to standard finite-difference or spectral schemes on uniform fine grids, this method shows significant savings in computational time and memory requirements proportional with the dimensionality of the problem. [Work supported by U.S. Army Medical Research Acquisition Activity through the University.]
Clinical exposure protocols for HIFU treatments of cancer of the liver and kidney
Authors: ter Haar Gail R. , Rivens Ian H. , Kennedy James E. , Wu Feng
Published: September 2013

High-intensity focused ultrasound surgery (HIFU) is a technique that is finding increasingly widespread clinical application. The potential of HIFU for the noninvasive treatment of deep-seated tumors is being explored. Treatment of these tumors uses an extracorporeal approach. A number of different devices are now available for delivering clinical HIFU treatments. This paper sets out methods for characterization of HIFU transducers and exposure protocols that would allow treatments to be compared. Clinical trials for the treatment of tumors of the liver and kidney are underway in the UK at the Royal Marsden Hospital, London and the Churchill Hospital, Oxford. This paper describes the physical and technical characteristics of the two devices being used to deliver treatments, and uses these as a basis for discussing the ultrasonic procedures that can be used, and the rationale for their choice. Clinical reference is given for illustrative purposes. The wide variety of exposure protocols that is being used in different clinical centers means that there is at present no uniformity of reporting in the literature. This paper therefore sets out recommended information that should be included in order that transducers and treatments can be compared.
Early 20th century acoustics apparatus in Iowa
Authors: Hanson Roger J.
Published: September 2013

In the first half of the 20th century G. W. Stewart was a physics faculty member at the University of Iowa (UI) with a distinguished record of research and teaching, especially in acoustics. Much of his research focused on the design and use of several types of acoustical filters. Some apparatus which he developed or utilized are still housed in the Department of Physics and Astronomy or are available in detailed diagrams. Demonstration apparatus (apparently homemade) from his era are still available for use. Carl E. Seashore, a renowned psychologist also at UI in the early 20th century, had interdisciplinary interests linking psychology, speech and hearing, music, and acoustics. He was responsible for obtaining an Henrici harmonic analyzer, a mechanical Fourier analyzer manufactured in Switzerland, a special grant from the state legislature during Depression conditions provided the funding. It resides in the Department of Speech Pathology and Audiology at UI. The Grinnell College Physics Historical Museum houses a set of 18 Helmholtz resonators and a Savart bell and resonator. Apparatus at Iowa State University, the University of Northern Iowa, and other Iowa institutions will also be described. Pictures and diagrams as well as some actual apparatus will be exhibited.
A two-stage approach to removing noise from recorded music
Authors: Berger Jonathan , Goldberg Maxim J. , Coifman Ronald C. , Goldberg Maxim J. , Coifman Ronald C.
Published: September 2013

A two-stage algorithm for removing noise from recorded music signals (first proposed in Berger et al., ICMC, 1995) is described and updated. The first stage selects the ‘‘best’’ local trigonometric basis for the signal and models noise as the part having high entropy [see Berger et al., J. Audio Eng. Soc. 42(10), 808–818 (1994)]. In the second stage, the original source and the model of the noise obtained from the first stage are expanded into dyadic trees of smooth local sine bases. The best basis for the source signal is extracted using a relative entropy function (the Kullback–Leibler distance) to compare the sum of the costs of the children nodes to the cost of their parent node; energies of the noise in corresponding nodes of the model noise tree are used as weights. The talk will include audio examples of various stages of the method and proposals for further research.
Evaluation of urban soundscape by future architects
Authors: Zhang Mei , Kang Jian
Published: September 2013

Urban soundscape design has drawn great attention along with the ever increasing urban noise level. Previous research shows that people with different social and demographic backgrounds may have different sound preferences in urban environment. For example, gender, age, and cultural background have been proved to affect peoples soundscape evaluation. In this research the soundscape evaluation by a group of architectural students was made, investigating how the future architectural/urban designers value the urban soundscape they experience everyday, and how they would like to design urban soundscape. The soundscape evaluation/walk was conducted with 60 students in a number of urban open public spaces in Sheffield, UK. The evaluation was both for the overall soundscape and for individual sounds. Eighteen indices with seven-point bipolar rating scale were used. Both connotative meanings of urban environment sounds, such as calming–agitating, interesting–boring and like–dislike, and denotative meanings, such as quiet–noisy, sharp–flat and smooth–rough, were considered. In addition, the students were asked to give design suggestions. The semantic differential technique was applied for the analysis. Comparison was also made between this special group and general public. The results are useful for studying the links/interactions between general architectural/urban design and the soundscape design. [Work supported by British Academy.]
Native sound category formation in simultaneous bilingual acquisition
Authors: Bosch Laura
Published: September 2013

The consequences of early bilingual exposure on the perceptual reorganization processes that occur by the end of the first year of life were analyzed in a series of experiments on the capacity to discriminate vowel and consonant contrasts, comparing monolingual and bilingual infants (Catalan/Spanish) at different age levels. For bilingual infants, the discrimination of target vowel contrasts, which reflect different amount of overlapping and acoustic distance between the two languages of exposure, suggested a U-shaped developmental pattern. A similar trend was observed in the bilingual infants discrimination of a fricative voicing contrast, present in only one of the languages in their environment. The temporary decline in sensitivity found at 8 months for vowel targets and at 12 months for the voicing contrast reveals the specific perceptual processes that bilingual infants develop in order to deal with their complex linguistic input. Data from adult bilingual subjects on a lexical decision task involving these contrasts add to this developmental picture and suggest the existence of a dominant language even in simultaneous bilingual acquisition. [Work supported by JSMF 10001079BMB.]