bluuebunny/crossref_metadata_2025 huggingface dataset:
A consideration on physical tuning for acoustical coloration in recording studio
Authors: Shimizu Yasushi
Published: October 2013

Coloration due to particular architectural shapes and dimension or less surface absorption has been mentioned as an acoustical defect in recording studio. Generally interference among early reflected sounds arriving within 10 ms in delay after the direct sound produces coloration by comb filter effect over mid- and high-frequency sounds. In addition, less absorbed room resonance modes also have been well known as a major component for coloration in low-frequency sounds. Small size in dimension with recording studio, however, creates difficulty in characterization associated with wave acoustics behavior, that make acoustical optimization more difficult than that of concert hall acoustics. There still remains difficulty in evaluating amount of coloration as well as predicting its acoustical characteristics in acoustical modeling and in other words acoustical tuning technique during construction is regarded as important to optimize acoustics appropriately to the function of recording studio. This paper presents a example of coloration by comb filtering effect and less damped room modes in typical post-processing recording studio. And acoustical design and measurement technique will be presented for adjusting timbre due to coloration based on psycho-acoustical performance with binaural hearing and room resonance control with line array resonator adjusted to the particular room modes considered.
NFL Films audio, video, and film production facilities
Authors: Berger Russ , Schrag Richard C. , Ridings Jason J.
Published: October 2013

The new NFL Films 200,000 sq. ft. headquarters is home for the critically acclaimed film production that preserves the NFL’s visual legacy week-to-week during the football season, and is also the technical plant that processes and archives football footage from the earliest recorded media to the current network broadcasts. No other company in the country shoots more film than NFL Films, and the inclusion of cutting-edge video and audio formats demands that their technical spaces continually integrate the latest in the ever-changing world of technology. This facility houses a staggering array of acoustically sensitive spaces where music and sound are equal partners with the visual medium. Over 90,000 sq. ft. of sound critical technical space is comprised of an array of sound stages, music scoring stages, audio control rooms, music writing rooms, recording studios, mixing theaters, video production control rooms, editing suites, and a screening theater. Every production control space in the building is designed to monitor and produce multi channel surround sound audio. An overview of the architectural and acoustical design challenges encountered for each sophisticated listening, recording, viewing, editing, and sound critical environment will be discussed.
Some analytic solutions for the dispersion and attenuation of sound in bubbly seawater
Authors: Goodman Ralph R. , Caruthers Jerald W.
Published: October 2013

The effect that air bubbles have on sound propagation is well known, and in the past three decades, due to advances in acoustic measurement technologies, has been the subject of several studies that investigate the bubble sizes and distributions due to breaking waves and ship wakes. The distribution of bubbles in size and total void fraction, and in time and space, plays a critical role in the determination of dispersion, refraction and attenuation. Bubble size distributions have been measured under different environments and by several techniques and have been represented usually with a power law or an exponential dependence. The authors have investigated a few distributions that are amenable to exact analytical solutions. These are power law distributions that have been chosen to give insight to realistic cases without significantly modifying the physics. The solutions to the integrals for dispersion and attenuation will be presented. They will be used to show the changes in the magnitudes of sound speed and attenuation under varying conditions.
On the underwater sound generated by the counterpropagating sea-surface wave
Authors: Naugolnykh Konstantin A. , Rybak Samuil A.
Published: October 2013

Two counterpropagating gravity-capillary waves of the same frequency, forming a standing wave on the sea surface, give rise to a sound wave traveling away from the surface [M. S. Longuet-Higgins (1950); L. M. Brekhovskikh (1966)]. The effect can be described in terms of three-wave nonlinear interaction [V. V. Goncharov, K. A. Naugolnykh, and S. A. Rybak (1977)]. The frequency and the wave number of the radiated wave are determined by the synchronism conditions. The surface waves propagating in the opposite directions can be generated by the action of the wind on the remaining swell of a cyclone or due to nonlinear interaction of the gravity-capillary waves. The progressive gravity-capillary waves superimposed on the flow produced by the finite-amplitude dominant gravity wave can be blocked at the points where its group velocity balance the convection by the larger-scale flow generating the reflected wave. As a result in the field of progressive waves produced by wind the counterpropagating wave appears generating the sound. [Work partially supported by Collaborative Linkage Grant No. 977 890.]
Rain parameter estimation using impact generated low-frequency acoustic signals
Authors: Mani T. K. , Pillai P. R. Saseendran , Kurian James , Hariharan Supriya M.
Published: October 2013

The role of rain generated acoustic signals in the frequency range 500 Hz–100 kHz to estimate the rain parameters is well known [Medwin et al., J. Acoust. Soc. Am. 92, 1613–1623 (1992)]. A study of utilizing the low-frequency component below 500 Hz, present in the rain generated acoustic noise, for estimation of rain parameters is performed in this paper. Raindrops falling from various heights are simulated using a drop generator. Gravity waves are produced in the water surface due to the drop impact and this causes a sinusoidal low-frequency damped pressure wave in water. This low-frequency signal is captured using a sensor assembly and analyzed. It is observed that this component is fairly constant in its frequency while amplitude is found to vary in accordance with the drop size as well as the velocity. Drop-size and its kinetic energy are determined and compared with those obtained from theoretical computations and by direct measurements. The results show that this new technique of analysis of rain generated acoustic signals yields rain parameters with good degree of accuracy. This method has the advantage of savings in computation time and simplicity of design.
Acoustic hemostasis
Authors: Crum L. , Andrew M. , Bailey M. , Beach K. , Brayman A. , Curra F. , Kaczkowski P. , Kargl S. , Martin R. , Vaezy S.
Published: October 2013

Over the past several years, the Center for Industrial and Medical Ultrasound (CIMU) at the Applied Physics Laboratory in the University of Washington has undertaken a broad research program in the general area of High Intensity Focused Ultrasound (HIFU). Our principal emphasis has been on the use of HIFU to induce hemostasis; in particular, CIMU has sought to develop a small, lightweight, portable device that would use ultrasound for both imaging and therapy. Such a technology is needed because nearly 50% of combat casualty mortality results from exsanguinations, or uncontrolled bleeding. A similar percentage occurs for civilian death due to trauma. In this general review, a presentation of the general problem will be given, as well as our recent approaches to the development of an image-guided, transcutaneous, acoustic hemostasis device. [Work supported in part by the USAMRMC, ONR and the NIH.]
Systematic acoustic loading of an aeroacoustic whistle
Authors: Slaton W. V. , Zeegers J. C. H.
Published: October 2013

Strong self-sustained acoustic oscillations may occur in a gas pipe network under certain gas flow velocities within the network. The pipe network under consideration consists of a main pipe, with a variable mean airflow, with two closed coaxial side branches of variable but equal length joined to the main pipe at right angles. Coupling between resonant acoustic standing waves and instabilities of the shear layers separating the flow in the main pipe from the stagnant gas in the closed side branches leads to strong acoustic oscillations (easily 10% of the mean pressure) at a frequency corresponding to the half-wavelength acoustic mode defined by the total side-branch length. The acoustic power available in the resonant mode has been measured to compare with theoretical predictions and previous two-microphone measurement techniques as well as to inspire confidence when designing an aeroacoustically driven thermoacoustic heat pump. The acoustic load consists of a variable acoustic resistance and coupled acoustic compliant volume, which is similar to devices used to measure power in thermoacoustic engines. Data will be presented which characterize the performance of the aeroacoustic sound source under variable acoustic loading. [Work supported by Shell International Exploration and Production B.V.]
Band-gap engineering in periodic acoustic stub tuners: Spectral gaps and transmission
Authors: Kushwaha Manvir S. , Wang X. F. , Vasilopoulos P.
Published: October 2013

A theoretical investigation on acoustic wave propagation in a periodically stubbed waveguide is reported. In general the waveguide segments and stubs are made of different materials. The acoustic wave in such a system has two independent polarizations: out-of-plane and in-plane modes. The band structure and transmission spectrum are studied for diverse geometries using a simple and efficient version of the transfer-matrix method. For the same material between the waveguide and symmetric stubs the width of some gaps can change, upon varying the stub length or width, by more than one order of magnitude. A further modulation can be achieved for different material between the stubs and the main waveguide or if the stubs are asymmetric. The gaps in the band structure of an infinitely long system correspond to those in the transmission spectrum of the same system but with finite number n of units. For n finite (i) there exist pseudogaps that gradually turn into complete gaps with increasing n and (ii) the introduction of defects gives rise to states in the gaps and leads to transmission resonances.
Modulation masking of lateralization based on envelope interaural phase differences
Authors: Sheft Stanley , Yost William A.
Published: October 2013

Modulation-filterbank models discard envelope phase above very low modulation rates. To evaluate the role of relative phase in binaural envelope processing, modulation masking of envelope-based lateralization was measured with a left/right task. A diotic 400-ms wideband noise was modulated by a two-tone function. An interaural phase difference was applied to the probe component of the modulator with the masker component always diotic. The probe modulation rate was 80, 160, or 320 Hz with masker rate varying from 40 to 1280 Hz. Masker modulation interfered with probe lateralization at all probe rates. With 80-Hz probe modulation, the masking function was asymmetric with maskers above the probe more effective than those below. At the higher probe modulation rates, interference was generally greatest when the probe and masker rates were close. However, function asymmetry persisted at these higher rates. In some conditions, a diotic phase shift of the masker had a significant effect. Unlike monaural results, binaural envelope processing showed high-rate phase sensitivity and asymmetric tuning. The asymmetric results and masker-phase effects are consistent with viewing the envelope manipulations as interaural gating asynchronies described by group delay in the modulation domain. [Work supported by NIH.]
Discrimination between harmonic tone complexes and bandpass noise signals presented within lowpass noise
Authors: van de Par Steven , Kohlrausch Armin , Breebaart Jeroen
Published: October 2013

Threshold levels were measured at which harmonic tone complex targets could be discriminated from bandpass noise targets both presented within a diotic 2-kHz lowpass filtered noise masker with 65 dB SPL. In the 3IFC paradigm, one interval contained a sine-phase tone complex (20-Hz spacing) while the remaining intervals contained a bandpass noise with the same bandwidth, center frequency (1 kHz) and overall level as the tone complex. In addition, detection thresholds were measured for both targets using the same masker. When interaurally in-phase targets with a 100-Hz bandwidth were used, discrimination thresholds were about 8 dB higher than the detection thresholds. When out-of-phase targets were used, the difference between discrimination and detection thresholds was 18 dB, which was mainly due to a decrease of about 15 dB of the detection thresholds (BMLD). For 1500-Hz wide targets, the discrimination and detection thresholds were more similar. For the in-phase condition, the discrimination and detection threshold overlapped while for the out-of-phase conditions, discrimination thresholds exceeded the detection thresholds by only 5 dB. Assuming that discrimination is based on the processing of the temporal structure of the targets, this processing seems to be more efficient for wide- than for narrow-band targets.
Underwater loudness for pure tones: Duration effects
Authors: Cudahy Edward A , Schwaller Derek , Fothergill David , Wolgemuth Keith
Published: October 2013

The loudness of underwater pure tones was measured by loudness matching for pure tones from 100 to 16,000 Hz. The standard was a one second tone at 1000 Hz. The signal duration was varied from 20 milliseconds to 5 seconds. Subjects were instructed to match the loudness of the comparison tone at one of the test frequencies to the loudness of the standard tone. Loudness was measured at the threshold, the most comfortable loudness, and the maximum tolerable loudness. The intensity of the standard was varied randomly across the test series. The subjects were bareheaded U.S. Navy divers tested at a depth of 3 meters. All subjects had normal in-air hearing. Tones were presented to the right side of the subject from an array of underwater sound projectors. The sound pressure level was calibrated at the location of the subject’s head with the subject absent. Loudness increased and threshold decreased as duration increased. The effect was greatest at the lowest and highest frequencies. The shape of the loudness contours across frequency and duration derived from these measurements are different from in-air measurements. [Research supported by ONR.]
Phonon localization methods through time and space: Experimental SAW phonon aspects on a cylindrical shell
Authors: Martinez Loic , Morvan Bruno , Izbicki Jean Louis
Published: October 2013

A transient experimental study of Surface Acoustic Wave (SAW) propagation along a 1D medium as a function of time leads to a 2D space–time signal collection. Previous studies have shown that 3D space-wave number–frequency representation S(x,k,f) allows the characterization of the space transient aspects of SAW generation [L. Martinez, J. Acoust. Soc. Am. 105, 952 (1999)]. In order to analyze the time transient aspect of phonon propagation, the 3D time–wave Number-Frequency representation Z(t,k,f) is proposed. The Z(t,k,f) matrix is obtained by short time Fourier transforming each time signal of the 2D time–wave number representation. The Z(t,k,f) representation is used to experimentally investigate SAW generation and propagation around a cylindrical shell (the relative thickness is equal to 0.03) surrounded by water and excited by a pulse (0.1 s duration). For the air filled shell, the Z(t,k,f=const) slices show the time sequence of the continuous flow of incident phonons striking the insonified side of the shell and their reflection or conversion in SAW phonons. The complex frequencies, direction of propagation and the time origin of all the phonons are identified. For the first time, the elastic Franz waves due to diffraction around the shell are also observed. For the water-filled shell the Z(t,k,f=const) slices point out two new major features. On the one hand, phonons trapped inside the fluid column of the shell are clearly identified. On the other hand, when the initial incidence angle enables the generation of a SAW, the SAW is generated at each internal striking point. A precise experimental ray model is deduced from these results, allowing us to link this transient experimental study with the theoretical results based on a steady state approach.
An acoustic comparison of two women’s infant- and adult-directed speech
Authors: Andruski Jean , Katz-Gershon Shiri
Published: October 2013

In addition to having prosodic characteristics that are attractive to infant listeners, infant-directed (ID) speech shares certain characteristics of adult-directed (AD) clear speech, such as increased acoustic distance between vowels, that might be expected to make ID speech easier for adults to perceive in noise than AD conversational speech. However, perceptual tests of two women’s ID productions by Andruski and Bessega [J. Acoust. Soc. Am. 112, 2355] showed that is not always the case. In a word identification task that compared ID speech with AD clear and conversational speech, one speaker’s ID productions were less well-identified than AD clear speech, but better identified than AD conversational speech. For the second woman, ID speech was the least accurately identified of the three speech registers. For both speakers, hard words (infrequent words with many lexical neighbors) were also at an increased disadvantage relative to easy words (frequent words with few lexical neighbors) in speech registers that were less accurately perceived. This study will compare several acoustic properties of these women’s productions, including pitch and formant-frequency characteristics. Results of the acoustic analyses will be examined with the original perceptual results to suggest reasons for differences in listener’s accuracy in identifying these two women’s ID speech in noise.
Very loud speech over simulated environmental noise tends to have a spectral peak in the F1 region
Authors: Ternstrom Sten , Bohman Mikael , Sodersten Maria
Published: October 2013

In some professions, workplace noise appears to be a hazard to the voice, if not to hearing. Several studies have shown that teachers and sports instructors, for example, are more prone to voice problems than average, prompting research on loud voice. Since on-location recordings are in many ways impractical, the running speech of 23 untrained speaker subjects (12 female, 11 male) was instead recorded in several types of loud noise that was presented over high-quality loudspeakers. Using adaptive cancellation techniques, the noise was then removed from the recordings, thus exposing the strained voices for analysis. The experiment produced a large body of data, only one aspect of which is reported here. In most subjects, the vowel spectrum as a function of voice SPL showed the expected behavior for low to moderate efforts, but developed a very pronounced peak in the F1 region at the highest efforts. This peak can be ascribed to the concerted action of several acoustic mechanisms, including source waveform asymmetry, F1 approximating one of the lower partials, and increased formant Q values due to a longer closed phase. [Work supported by the Swedish Council for Working Life and Social Research, Contract No. 2001-0341.]
Inferring array geometry from multiple sources of opportunity
Authors: Boyle Frank A. , Grant David E.
Published: October 2013

A beamformer’s performance is sensitive to the accuracy of the element location estimates. Array element localization is a reasonably simple task when a source is present with a known location. The problem is more difficult with a source whose position is unknown. Techniques commonly require assumptions to be made regarding the source’s range. A method for determining the array’s geometry from multiple sources of opportunity has been formulated. Array geometry is determined from multiple observations of parallax from each source, for a collection of hydrophone pairs in the array. The array’s geometry is built up from the combined orientations of hydrophone pairs. In its current form, the technique requires accurate knowledge of hydrophone pair separation. The presentation will include an application of the method to simulated array data and a discussion of current limitations.
Beamforming using indefinite term for arbitrarily located microphones
Authors: Nakajima Hirofumi , Takaaki Yamanaka , Nakagawa Hiroshi
Published: October 2013

The design of filter coefficients for a beamforming algorithm constructed of finite impulse response filters and adders was investigated. Designing filter coefficients can be represented as a linear inverse problem, and using the indefinite term of the linear equation, a filter having the smallest sidelobe beam pattern based on the least-square estimation criterion can be designed. This design method is represented by a closed form equation using singular value decomposition and a pseudo-inverse matrix, so it does not need parameter adjustment, as do adaptive methods. It can be used for arbitrarily located microphones; it was applied to a sound visualization system using a spherical microphone array (SMA). At the meeting, this design method and its directivity performance when applied to a SMA will be described.
A comparison of models for the reflection loss of acoustic waves from a smooth water/sediment interface
Authors: Isakson Marcia J. , Worley Andrew
Published: October 2013

Reflection-loss measurements have been inverted using a composite poro-elastic model to produce realistic sediment properties. This type of inversion could provide a noninvasive method of characterizing sediments. However, it is not well understood how measurement variability affects the outcome of the inversion. When measurement variability is taken into account, other models may be able to predict reasonable sediment properties. In this study, several models will be considered for their ability to produce realistic sediment parameters and their fit to the data. Models considered will be the visco-elastic model, the Biot/Stoll model, the effective density fluid model, the Buckingham model, and the composite Biot squirt flow/shear model. Each model will be inverted using a simulated annealing algorithm with OASR as the forward model. Special emphasis will be placed on inverting within the statistical nature of the data. [Work supported by ONR, Ocean Acoustics.]
Measurements of subcritical grazing angle detection of targets buried under a rippled sand interface
Authors: Lopes J. L. , Nesbitt C. L. , Lim R. , Tang D. , Williams K. L. , Thorsos E. I.
Published: October 2013

A series of controlled measurements were conducted to investigate shallow grazing angle acoustic detection of targets buried in sand having a rippled sediment–water interface. The measurements were performed in a 13.7-m deep, 110-m long, 80-m-wide test-pool with a 1.5-m layer of sand on the bottom. A silicone oil filled target sphere was buried under a rippled interface with contours formed by scraping the sand with a machined rake moved along a guide frame. Broadband, broad beam transducers were placed onto the shaft of a tilting motor. The transducers and tilting motor were attached to an elevated rail that enabled this assembly to be translated horizontally, permitting acquired data to be processed using synthetic aperture sonar techniques. Acoustic backscatter data were acquired at subcritical grazing angles in the frequency range of 10 to 50 kHz for various ripple wavelengths and heights. For each bottom configuration, the ripple profile over the buried target was measured using the In-situ Measurement of Porosity 2 (IMP2) system. Measurement results are presented that illustrate target detection via ripple scattering. The characteristics of the target return are found to depend sensitively on the ripple height and wavelength. [Work supported by ONR.]
Mechanical loading of a spherical hydrophone embedded in a sediment
Authors: Kargl Steven G.
Published: October 2013

The free-field calibration of the response of a hydrophone is typically performed in water and it is often assumed that the hydrophone is insensitive to loading when immersed in other materials. Hydrophones are routinely deployed in sandy sediments to measure the penetration of an acoustic field from a sonar. Models of the mechanical response of a spherical hydrophone will be discussed. Space is split into three concentric regions and an infinite external region. The innermost region is a vacuum, the inner spherical shell is an active element (e.g., a piezoelectric ceramic), and the outer shell is an impedance matching material. The active element is modeled as a homogenous elastic material such that its piezoelectric properties are neglected. The external medium can be either a fluid, elastic, or a poroelastic medium. The mechanical impedance shows that the loading causes a shift in the resonance frequency of the hydrophone as well as a change in the Q of the resonance. The sensitivity of the hydrophone will also be discussed. [Work supported by ONR.]
One approach to architectural acoustics in education
Authors: Jaffe J. Christopher
Published: October 2013

In the fall of 1997, Dean Alan Balfour of the School of Architecture at the Rennselaer Polytechnic Institute asked me to introduce an undergraduate 14 credit certificate course entitled ’’Sonics in Architecture.‘‘ Subsequently, the program was expanded to include a Master’s Degree in Building Science. This paper discusses the trials and tribulations of building a scientific program in a liberal arts school. In addition, the problem of acquiring the research funds needed to provide tuition assistance for graduate students in Architectural Acoustics is reviewed. Information on the curriculum developed for both the lecture and laboratory courses is provided. I will also share my concerns regarding the teaching methods currently prevalent in many schools of architecture today, and how building science professionals might assist in addressing these issues.
The acoustics teaching drawdown at architectural schools in America: How to prepare learning materials for the new curricula
Authors: Egan M. David
Published: October 2013

In the early 1990s, the Association of Collegiate Schools of Architecture (ACSA) directory listed more than forty faculty members as teaching a course on acoustics. Today at the more than 120 ACSA full-member schools, there are only eight faculty members listed as teaching acoustics. Clearly the focus at most architecture schools in North America does not include the thorough study of science and technology. Courses in acoustics, illumination, HVAC systems, and fire protection are no longer included in curricula of most schools. Unlike studies in law and medicine, each school controls its own curriculum and what it calls its degree [A. O. Dean, Arch. Record (August 2002), pp. 84–92]. Learning materials have been developed to aid architecture professors who now must cover acoustics in the design studio. These materials, based on more than three decades of experience teaching and writing seven books on building technologies, also are intended to support self-study by students and design professionals. Examples of self-study exercises and hands-on exercises will be described [M. D. Egan, Arch. Acoustics Workbook (2000)]. A checklist of ‘‘writing principles’’ for the preparation of educational materials in architectural acoustics also will be presented.
Automatic type classification and speaker identification of african elephant (Loxodonta africana) vocalizations
Authors: Clemins Patrick J. , Johnson Michael T.
Published: October 2013

This paper presents a system for automatically classifying African elephant vocalizations based on systems used for human speech recognition and speaker identification. The experiments are performed on vocalizations collected from captive elephants in a naturalistic environment. Features used for classification include Mel-Frequency Cepstral Coefficients (MFCCs) and log energy which are the most common features used in human speech processing. Since African elephants use lower frequencies than humans in their vocalizations, the MFCCs are computed using a shifted Mel-Frequency filter bank to emphasize the infrasound range of the frequency spectrum. In addition to these features, the use of less traditional features such as those based on fundamental frequency and the phase of the frequency spectrum is also considered. A Hidden Markov Model with Gaussian mixture state probabilities is used to model each type of vocalization. Vocalizations are classified based on type, speaker and estrous cycle. Experiments on continuous call type recognition, which can classify multiple vocalizations in the same utterance, are also performed. The long-term goal of this research is to develop a universal analysis framework and robust feature set for animal vocalizations that can be applied to many species.
Toward standardization of noise exposure in animal bioacoustics
Authors: Burkard Robert
Published: October 2013

In the United States, the American National Standards Institute (ANSI) Accredited Standards Committee on Bioacoustics S3 develops voluntary standards related to psychological and physiological acoustics, including areas such as general acoustics, vibration, and shock. Several years ago, an S3 working group (WG) was formed, WG90 Animal Bioacoustics, with the goal of developing guidelines and standards in the area of animal bioacoustics, including relevant terminology, procedures to quantify noise exposure, and the effects of noise exposure on animals. The scope of this working group involves both terrestrial and marine animals, and their environments. Although ANSI Standards are voluntary, the development of accepted sound measurement procedures is needed before any legislation can be implemented that is intended to protect these animals from sound exposures detrimental to their long-term survival. To date, no standards have emerged from the Animal Bioacoustics working group. The purpose of this presentation is to provide an overview of the ANSI standards development process, briefly review some of standards that have been developed that are intended to quantify human exposure to sound, as well as describe the standards that need to be developed in order to protect both terrestrial and marine animals from excessive sound exposure.
A comparison of single crystal versus ceramic piezoelectric materials for acoustic applications
Authors: Tressler James F.
Published: October 2013

For nearly fifty years, piezoelectric ceramics (primarily from the PZT family) have been the materials of choice as the active elements in sound projectors and receivers, medical ultrasound probes, etc. There is currently great interest in the materials community in the use of newly discovered single crystal relaxor ferroelectric materials as a replacement in applications that currently utilize piezoelectric ceramics. The salient features of single crystal piezoelectrics are strains an order of magnitude larger than are achievable in PZT and electromechanical coupling coefficients on the order of 90 percent. This presentation will provide a more thorough comparison of the physical and piezoelectric properties of single crystal piezoelectrics versus conventional PZT piezoceramics. This will hopefully provide the transducer designer with a better understanding of the pros and cons in the use of single crystals. In addition, a brief review of single crystal synthesis procedures will be described. Finally, some acoustic devices utilizing both single crystals and piezoceramics will be compared. [Work supported by DARPA and ONR Code 321-TS.]
Examining surface sealing and crusting using the acoustic to seismic transfer function
Authors: Leary Del , Hickey Craig J. , Sabatier James M. , DiCarlo David A.
Published: October 2013

Soil sealing is examined by measuring the acoustic to seismic (A/S) transfer function. An A/S transfer function is a swept sine measurement using a suspended loud speaker to impinge acoustic energy from the air onto a soil sample. A laser Doppler vibrometer (LDV) is used to obtain the surface particle velocity as a measure of the seismic energy that has been transferred into the soil. This technique is noncontact and therefore allows successive measurements to be taken in time as the surface crust is formed. Soil samples are rained upon then allowed to dry forming a crust or seal that changes both the stiffness and hydraulic properties of the surface layer. Neshoba soils tested show a quantifiable decrease in the seismic energy transferred, as well as an increase in correlation between successive trials, as the crust forms. Additional measurements done with a submerged transducer show an even greater decrease in surface velocity. Current studies also include an acoustic reflection technique to measure changes in the hydraulic properties. [Work supported by USDA ARS.]
Structural acoustics for the violin
Authors: Bissinger George , Williams Earl G.
Published: October 2013

The violin is a long-standing problem in acoustics due to the complexity of its shape, the interactivity of its various modes of response, and the inherent complications of coupling these to the acoustic field, independent of any quality aspects. By combining zero-mass loading modal analysis of the violin with simultaneous acoustic measurements over a sphere in an anechoic chamber, major acoustic energy sources were identified among the coterie of corpus (top+back+ribs) modes and interior cavity (via two ports, or f-holes) modes up to 4 kHz. Direct radiation from substructures such as the neck-fingerboard, bridge, and tailpiece was not significant. For each mode the total damping and the radiation efficiency and damping were computed, along with a simple top-back radiation directivity ratio using rms radiativities. The fraction-of-vibrational-energy-radiated was estimated from the radiation-to-total-damping ratio. A new addition to the modal violin acoustics investigations was the application of near-field patch holography to help determine the relative contributions of corpus and port radiation to overall violin radiativity. [Work supported by NSF and ONR.]
Effect of body shape on vibration of electric guitars
Authors: Russell Daniel A. , Haveman Wesley S. , Broden Willis , Weibull N. Pontus
Published: October 2013

The body vibrations of an electric guitar are typically ignored since the string vibrations are converted to sound through the use of a magnetic pickup. However, vibrations in the neck have been shown to cause dead spots at certain fret positions [H. Fleischer, J. Acoust. Soc. Am. 105, 1330 (1999)]. In this paper we compare the vibrational mode shapes and frequencies of three electric guitars with different body shapes. Two guitars are solid-body electrics: one with a body shape which is symmetric about the neck axis (Epiphone Coronet) and the other which is not (Gibson Explorer). Mode shapes and frequencies are considerably different for the body, though neck vibrations are more closely related. The third guitar is an arched top hollow-body electric (Gibson ES-335). For this guitar, the top and back plates and the air cavities may also contribute to the guitar sound quality. Mode shapes and frequencies are determined from experimental modal analysis using an impact hammer and accelerometer.
On the scaling of free-reed organ pipes: A comparison of 19th-century theories to modern nonlinear models
Authors: Braasch Jonas
Published: October 2013

After their introduction in the 19th century, the scaling of free reed organ pipes was often done on the basis of investigations by W. Weber, J. G. Töpfer, and F. Haas. Especially, Töpfer is often named as the founder of mathematical/physical oriented scaling. Unfortunately, it was impossible in the 19th century to derive a number of measures (e.g., optimal lengths of a conical pipe and the boot) theoretically. In this presentation it is demonstrated how recent theories can be used to derive some of those measures. For this purpose, a one-dimensional physical model was developed. The model uses the reed generator developed by Tarnopolsky et al. [J. Acoust. Soc. Am. 108, 400–406 (2001)] and a wave-guide model for the resonator so as to determine the optimal resonator and boot dimensions. Wrong assumptions that were made in the 19th century will be also addressed. For example, organ builders frequently used the solution of Weber to determine the optimal resonator length. The solution of Weber was aimed to make the reed pipe’s frequency independent from temperature and blowing pressure, but what the organ builders would have needed is a pipe whose frequency is mainly determined by the resonator length, so that the pipes would detune with the flue pipes, when the temperature changes.
Seeking NIH funding: Defining the process
Authors: Shekim Lana
Published: October 2013

The presentation will provide a brief introduction to the National Institute on Deafness and other Communication Disorders (NIDCD) with emphasis on the Voice and Speech program in the Division of Extramural Research. The process of seeking NIH funding will be outlined and a number of funding mechanisms will be described. The peer review process and the time course of a grant application will be highlighted.
Office of Naval Research funding strategies
Authors: Schmidt-Nielsen Astrid
Published: October 2013

The best strategies for obtaining military research funding can be quite different from NIH and NSF. Funding opportunities at the Office of Naval Research will be discussed. Different types of Navy/military funding will be described, and strategies for obtaining various types of funding, including the Young Investigator Program, will be discussed.
Coupled auralization and virtual video for immersive multimedia displays
Authors: Henderson Paul D. , Torres Rendell R. , Shimizu Yasushi , Radke Richard , Lonsway Brian
Published: October 2013

The implementation of maximally-immersive interactive multimedia in exhibit spaces requires not only the presentation of realistic visual imagery but also the creation of a perceptually accurate aural experience. While conventional implementations treat audio and video problems as essentially independent, this research seeks to couple the visual sensory information with dynamic auralization in order to enhance perceptual accuracy. An implemented system has been developed for integrating accurate auralizations with virtual video techniques for both interactive presentation and multi-way communication. The current system utilizes a multi-channel loudspeaker array and real-time signal processing techniques for synthesizing the direct sound, early reflections, and reverberant field excited by a moving sound source whose path may be interactively defined in real-time or derived from coupled video tracking data. In this implementation, any virtual acoustic environment may be synthesized and presented in a perceptually-accurate fashion to many participants over a large listening and viewing area. Subject tests support the hypothesis that the cross-modal coupling of aural and visual displays significantly affects perceptual localization accuracy.
Experimental and numerical investigation of tissue harmonic imaging (THI)
Authors: Jing Yuan , Yang Xinmai , Cleveland Robin O.
Published: October 2013

In THI the probing ultrasonic pulse has enough amplitude that it undergoes nonlinear distortion and energy shifts from the fundamental frequency of the pulse into its higher harmonics. Images generated from the second harmonic (SH) have superior quality to the images formed from the fundamental frequency. Experiments with a single element focused ultrasound transducer were used to compare a line target embedded in a tissue phantom using either fundamental or SH imaging. SH imaging showed an improvement in both the axial resolution (0.70 mm vs 0.92 mm) and the lateral resolution (1.02 mm vs 2.70 mm) of the target. In addition, the contrast-to-tissue ratio of the target was 2 dB higher with SH imaging. A three-dimensional model of the forward propagation has been developed to simulate the experimental system. The model is based on a time-domain code for solving the KZK equation and accounts for arbitrary spatial variations in all tissue properties. The code was used to determine the impact of a nearfield layer of fat on the fundamental and second harmonic signals. For a 15 mm thick layer the SH side-lobes remained the same but the fundamental side-lobes increased by 2 dB. [Work supported by the NSF through the Center for Subsurface Sensing and Imaging Systems.]
A voltage-doubling (2-kV) pulser for biomedical ultrasound measurements
Authors: Gammell Paul M. , Harris Gerald R.
Published: October 2013

High-voltage pulsers offer advantages in some biomedical ultrasound measurement applications, such as driving focused transducers for bioeffects studies, or transiently exciting plane, thick transducers for broadband measurements of attenuation or frequency response of receiving transducers. Because the duty cycle is low (typically less than 0.1%), bulky, expensive pulsers having large temporal-average power capability are not required. In the present design integrated gate bipolar transistors (IGBTs) are used to energize the ultrasound transducer. This solid-state switching device can handle large currents, has a low on-resistance, and can be turned off as well as on by its gate signal. However, widely available devices are limited to 1200-V peak. Therefore, the present design charges two capacitors in parallel and then uses two IGBTs to connect them in series to produce the output pulse. With a 1200-V supply this approach produces a pulse of 2100 V into a 50-Ω load at a 200-Hz repetition rate. The length of the output pulse is determined by the controlling input TTL pulse unless small capacitors are used, in which case a decaying exponential pulse is obtained. This design is readily reproduced and the components, exclusive of the power supply, cost less than $100.
Stress effects on coarticulation in English and Greek
Authors: Koenig Laura , Okalidou Areti
Published: October 2013

The effects of stress on production variability and V-to-V coarticulation were compared in American English and Greek, two languages which differ in vowel inventory size and in the magnitude of V-to-V coarticulation (Okalidou and Koenig, 1999). Six speakers, one male and two females from each language, were recorded producing nonsense VCV utterances in a carrier phrase, with randomly alternating stress. The Greek stimuli included all five vowels of the language; the English stimuli included the closest counterparts of the Greek vowels. The medial plosive consonants alternated between the bilabial and alveolar place of articulation, yielding different degrees of coarticulatory resistance (Recasens, 1985, 1989). Plosives were chosen to have similar VOT values across languages in order to minimize duration effects. A comparison of stressed versus unstressed vowel areas reveals significant differences across languages. Specific vowel effects and language effects are also noted with respect to changes in production variability under the stressed versus unstressed conditions. The magnitude of V-to-V influences as a function of stress and position is discussed in terms of the above crosslinguistic comparison in order to obtain further insight on the coarticulatory behavior of languages which differ in the size of vowel inventory (Manuel and Krakow, 1984).
Cross-language and speaker differences in the durational patterns of different topic transition types
Authors: Smith Caroline , Hogan Lisa
Published: October 2013

Previous work [Smith and Hogan (2001), (2002)] has shown that the organization of topics in a text affects durational patterning when the text is read aloud. Comparable texts in English, French, and Japanese were selected, and native speakers of each language were recorded reading them aloud. For all three texts, the transition in topic from each sentence to the next was labeled as a Shift, Continuation, or Elaboration. Acoustic measurements were made of lengthening of the sentence-final word, the duration of pauses between sentences and changes in speaking rate from one sentence to the next, and in all languages, these measures were significantly different for different topic transition types. The direction and magnitude of the effects differed considerably among the single speakers of the three languages examined so far. However, with just one speaker per language, it is impossible to distinguish language-specific from speaker-specific behavior. Additional data from more speakers will be reported, suggesting that differences among languages can be attributed to known prosodic differences, whereas differences among speakers of the same language are less systematic. [Work supported by NSF Grant No. BCS-9983106.]
Acoustic effects of near-bottom soliton packets
Authors: Chin-Bing Stanley A. , Warn-Varnas Alex C. , King David B. , Lamb Kevin G. , Hawkins James A. , Lynch James F.
Published: October 2013

The winter 1997 Primer4 experiment was conducted on the shelfbreak and continental slope south of Cape Code in the Middle Atlantic Bight. Internal solitary waves were surveyed with rapid-sampling thermistor chains, current meters, and an upward looking ADCP. Using the available environmental data we have simulated the generation of these near-bottom solitary internal waves in this region using a forcing tidal velocity of 0.3 m/s to initiate the primitive equation Lamb model. The simulated soliton packets compare favorably in period and amplitude with the measured data taken in the winter 1997 Primer4 experiment. Previously, resonance effects leading to anomalous signal losses have been observed in numerous simulations of acoustic propagation through near-surface soliton packets. The objective of this work is to determine if similar resonance effects are caused by the interaction of the acoustic field with these near-bottom soliton packets. In contrast to our previous acoustic simulations, it was necessary to place the acoustic source and receivers above the thermocline for these near-bottom soliton packet studies. Simulation results will be presented that illustrate the similarities and differences between the acoustic effects produced by the near-surface and near-bottom soliton packets. [Work supported by ONR/NRL.]
Temporal coherent and total intensity fluctuation of mid-frequency acoustic wave propagation during SWAT 2000 experiment
Authors: Yamaoka Haruhiko , Yamamoto Tokuo
Published: October 2013

Temporal coherent and total intensity fluctuations of acoustic wave propagation have been measured during SWAT (Shallow Water Acoustic Technology) 2000 Experiment data. The objective of this paper is to investigate the effect of the temporal fluctuation of an acoustic signal in shallow water. The acoustic propagation experiment was carried out among the three bottom mounted sonar towers, that were located in a triangle formed by 3, 4 and 5 km ranges. The center frequency of the acoustic signal is 5.5 kHz. A total of 32 hours acoustic data was sampled by a 2 min or 20 min sampling interval. In addition, oceanographic data including current velocity profile data and sound speed data is used to estimate the internal wave activity on the observation triangle. The time series of coherent intensity quickly attenuates, while the total intensity is maintained with weak fluctuation. According to the reciprocal transmission data, the reciprocity of coherent intensity is significantly distorted by the existence of a large internal wave, while the total intensity retains the reciprocity. The characteristics of these quantities are discussed by using the PE (Parabolic Equation) model. [Work supported by ONR 321OA, NIRE, and MEST.]