bluuebunny/crossref_metadata_2025 huggingface dataset:
Multimodal interaction in real and virtual concert halls
Authors: Larsson Pontus , Västfjäll Daniel , Kleiner Mendel
Published: September 2013

Recently, researchers within the field of room acoustics have shown an increased interest for the understanding of how different modalities, especially vision and audition, interact in the concert hall experience. Computer auralization and virtual reality technology have brought means to efficiently study such auditory-visual interaction phenomena in concert halls. However, an important question to address is to what extent the results from such studies agree with real, unmediated situations. In this paper, we discuss some of the auditory–visual cross-modal effects discovered in previous experiments, and an account of cross-modal phenomena in room acoustic perception is proposed. Moreover, the importance of measuring simulation fidelity when performing cross-modal experiments in virtual concert halls is discussed. The conclusions are that one can expect auditory–visual interaction effects to occur in both real and virtual rooms, but that simulation fidelity might affect the results when performing experiments in virtual conditions.
Interaction of vestibular, echolocation, and visual modalities guiding flight by the big brown bat, Eptesicus fuscus
Authors: Horowitz Seth S. , Simmons James A.
Published: September 2013

The big brown bat (Eptesicus fuscus) is an aerial-feeding insectivorous species that relies on echolocation to avoid obstacles and to detect flying insects. Spatial perception in the dark using echolocation challenges the vestibular system to function without substantial visual input for orientation. IR thermal video recordings show the complexity of bat flights in the field and suggest a highly dynamic role for the vestibular system in orientation and flight control. Laboratory studies of flight behavior under illuminated and dark conditions in both static and rotating obstacle tests were carried out while administering heavy water (D2O) to bats to impair their vestibular inputs. Eptesicus carried out complex maneuvers through both fixed arrays of wires and a rotating obstacle array using both vision and echolocation, or when guided by echolocation alone. When treated with D2O in combination with lack of visual cues, bats showed considerable decrements in performance. These data indicate that big brown bats use both vision and echolocation to provide spatial registration for head position information generated by the vestibular system.
A shallow water ocean acoustics inverse problem
Authors: Stickler David
Published: September 2013

A shallow water ocean acoustics experiment is described from which it is possible to determine in principle the scattering data necessary to recover the sound speed in the ocean bottom. This data is a ‘‘reflection coefficient.’’ The essential assumptions are that the speed in the ocean is known but unknown in the bottom and that the measurements are made in the ocean layer.
Effects of sound speed fluctuations in the water column on geoacoustic parameter estimates
Authors: Becker Kyle M.
Published: September 2013

The effects of environmental variability on acoustic propagation and sonar performance in shallow water has received much attention in recent literature. Of particular interest is the influence of water column variability on acoustic propagation and the subsequent effects on geoacoustic inversion. In this paper, a modal-based inversion method is considered with the inclusion of internal waves in a shallow-water waveguide. The input data to the inversion algorithm are estimates of horizontal wavenumbers corresponding to the propagating modes of a cw point-source field. Often, wavenumber estimation is performed under the assumption that the pressure field can be represented by an adiabatic mode sum. However, it is well known that sound speed fluctuations in the water column due to internal waves promote the coupling of energy between propagating acoustic modes, thus violating the adiabatic assumption. Nevertheless, it was recently demonstrated that sound speed fluctuations in the water column due to a weak deterministic internal wave field can enhance spectral wavenumber estimates [Becker and Frisk, in Impact of Littoral Variability on Acoustic Predictions and Sonar Performance (Kluwer, Dordrecht, 2002)]. That work is extended to compare inversion results for wavenumber estimates obtained both with and without internal waves. [Work supported by ONR Ocean Acoustics.]
The noise-cooling tradeoff in electronic equipment
Authors: Lyon Richard H.
Published: September 2013

The noise produced by cooling air passing through electronics packages arises from two sources. One source is the noise of the air-moving fan of either an axial or centrifugal type. This noise may have tonal components and both those components and the broad band noise are dependent on the way that the fan is placed in the unit and on how close the operation is to the design operating point. Often, this can be the dominant noise source. The other source produces random noise due to the turbulent flow of air through the unit. Because the turbulent airflow is also responsible for heat transfer between the components and the air stream, we can regard this part of the noise as the irreducible noise due to cooling. If fan noise were eliminated, this part of the noise must remain. There is a relation therefore between the irreducible noise and the cooling of the unit. But the fan noise must also be considered. The relation between total airflow related noise and cooling requirements is developed in this paper.
Investigating nonlinearity in acoustic landmine experiments using a clamped-plate soil oscillator
Authors: Duong Dang V. , Korman Murray S.
Published: September 2013

This project investigates the nonlinear effects involved in the detection of plastic landmines using the acoustic-to-seismic coupling techniques developed by Sabatier (linear methods) and Donskoy (nonlinear methods). The soil-plate oscillator is a laboratory apparatus that represents a good physical model for the VS 1.6 and VS 2.2 inert anti-tank plastic landmines. The apparatus consists of a thick-walled cylinder filled with sifted homogeneous soil resting on a thin elastic plate that is clamped to the bottom of the column. Using a loudspeaker (located over the soil) that is driven by a swept sinusoid, tuning curve experiments are performed. The vibration amplitude versus frequency is measured on a swept spectrum analyzer using an accelerometer located on the soil–air interface or under the plate. The ‘‘backbone’’ curve shows a linear decrease in peak frequency versus increasing amplitude. A two-tone test experiment is performed using two loudspeakers generating acoustic frequencies (closely spaced on either side of resonance, typically ∼100 Hz). A collection of combination frequency component profiles (along with the primaries) are measured across the soil surface. In particular, a double peaked profile occurred at 2f1+f2 corresponding to a common timpani mode. [Work sponsored by U.S. Army Communications-Electronics Command RDEC, NVESD, Fort Belvoir, VA.]
Cavitation nucleation
Authors: Crum Lawrence A.
Published: September 2013

For his dissertation research at Harvard, Bob Apfel chose the subject of homogeneous nucleation, and conceived of some ingenious experiments to test existing theories. By selecting a small microdroplet of liquid, he could make the reasonable assumption that no inhomogeneities were present to serve as preferential sites for liquid rupture. However, Bob also studied dirty liquids, as well as very clean ones, and wrote some seminal papers on inhomogeneous nucleation, in which he developed the Golden rule: Know thy liquid! Currently, considerable attention has been devoted to the study of cavitation generation in vivo, particularly in blood, and, for this case, the nucleation conditions are much different than those for normal liquids. In this presentation, I will review some of Bob’s pioneering studies and present some of our latest studies of cavitation inception, both in vitro and in vivo.
Shape oscillations of acoustically levitated drops in water: Early research with Bob Apfel on modulated radiation pressure
Authors: Marston Philip L.
Published: September 2013

In 1976, research in collaboration with Bob Apfel demonstrated that low-frequency shape oscillations of hydrocarbon drops levitated in water could be driven using modulated radiation pressure. While that response to modulated ultrasound was subsequently extended to a range of systems, the emphasis here is to recall the initial stages of development in Bob Apfel’s laboratory leading to some publications [P. L. Marston and R. E. Apfel, J. Colloid Interface Sci. 68, 280–286 (1979); J. Acoust. Soc. Am. 67, 27–37 (1980)]. The levitation technology used at that time was such that it was helpful to develop a sensitive method for detecting weak oscillations using the interference pattern in laser light scattered by levitated drops. The initial experiments to verify this scattering method used shape oscillations induced by modulated electric fields within the acoustic levitator. Light scattering was subsequently used to detect shape oscillations induced by amplitude modulating a carrier having a high frequency (around 680 kHz) at a resonance of the transducer. Methods were also developed for quantitative measurements of the drop’s response and with improved acoustic coupling drop fission was observed. The connection with research currently supported by NASA will also be noted.
Testing thin film adhesion strength acoustically
Authors: Madanshetty Sameer I. , Wanklyn Kevin M. , Ji Hang
Published: September 2013

A new method of measuring the adhesion strength of thin films to their substrates is reported. The method is based on an analogy with the common tensile test of materials. This is an acoustic method that uses acoustic microcavitation to bring about controlled erosion of the thin film. Based on the insonification pressure and the time to complete erosion, the adhesion strength is assessed. The measurements correctly rank order a set of thin film samples of known adhesion strengths.
Are vowel errors influenced by consonantal context in the speech of persons with aphasia?
Authors: Gelfer Carole E. , Bell-Berti Fredericka , Boyle Mary
Published: September 2013

The literature suggests that vowels and consonants may be affected differently in the speech of persons with conduction aphasia (CA) or nonfluent aphasia with apraxia of speech (AOS). Persons with CA have shown similar error rates across vowels and consonants, while those with AOS have shown more errors for consonants than vowels. These data have been interpreted to suggest that consonants have greater gestural complexity than vowels. However, recent research [M. Boyle et al., Proc. International Cong. Phon. Sci., 3265–3268 (2003)] does not support this interpretation: persons with AOS and CA both had a high proportion of vowel errors, and vowel errors almost always occurred in the context of consonantal errors. To examine the notion that vowels are inherently less complex than consonants and are differentially affected in different types of aphasia, vowel production in different consonantal contexts for speakers with AOS or CA was examined. The target utterances, produced in carrier phrases, were bVC and bV syllables, allowing us to examine whether vowel production is influenced by consonantal context. Listener judgments were obtained for each token, and error productions were grouped according to the intended utterance and error type. Acoustical measurements were made from spectrographic displays.
The effects of Parkinson’s disease on the production of contrastive stress
Authors: Cheang Henry S. , Pell Marc D.
Published: September 2013

Reduced speech intelligibility has been observed clinically among patients with Parkinson’s disease (PD); one possible contributor to these problems is that motor limitations in PD reduce the ability to mark linguistic contrasts in speech using prosodic cues. This study compared acoustic aspects of the production of contrastive stress (CS) in sentences that were elicited from ten subjects with PD and ten matched control subjects without neurological impairment. Subjects responded to questions that biased them to put emphasis on the first, middle, or last word of target utterances. The mean vowel duration and mean fundamental frequency (F0) of each keyword were then measured, normalized, and analyzed for possible differences in the acoustic cues provided by each group to signal emphatic stress. Both groups demonstrated systematic differences in vowel lengthening between emphasized and unemphasized words across word positions; however, controls were more reliable than PD subjects at modulating the F0 of emphasized words to signal its location in the utterance. Group differences in the F0 measures suggest one possible source of the impoverished intelligibility of Parkinsonian speech and will be investigated in a subsequent study that looks at the direct impact of these changes on emphasis perception by listeners. [Work supported by CIHR.]
Discrimination and identification of long vowels in children with typical language development and specific language impairment
Authors: Datta Hia , Shafer Valerie , Kurtzberg Diane
Published: September 2013

Researchers have claimed that children with specific language impairment (SLI) have particular difficulties in discriminating and identifying phonetically similar and brief speech sounds (Stark and Heinz, 1966; Studdert-Kennedy and Bradley, 1997; Sussman, 1993). In a recent study (Shafer et al., 2004), children with SLI were reported to have difficulty in processing brief (50 ms), phonetically similar vowels (/I-E/). The current study investigated perception of long (250 ms), phonetically similar vowels (/I-E/) in 8- to 10-year-old children with SLI and typical language development (TLD). The purpose was to examine whether phonetic similarity in vowels leads to poorer speech-perception in the SLI group. Behavioral and electrophysiological methods were employed to examine discrimination and identification of a nine-step vowel continuum from /I/ to /E/. Similar performances in discrimination were found for both groups, indicating that lengthening vowel duration indeed improves discrimination of phonetically similar vowels. However, these children with SLI showed poor behavioral identification, demonstrating that phonetic similarity of speech sounds, irrespective of their duration, contribute to the speech perception difficulty observed in SLI population. These findings suggest that the deficit in these children with SLI is at the level of working memory or long term memory representation of speech.
Speech prosody in Friedreich’s and olivo-ponto cerebellar atrophy
Authors: Casper Maureen
Published: September 2013

A critical issue in the study of speech motor control is the identification of the mechanisms that generate the temporal flow of serially ordered articulatory events. Two staged models of serial ordered events (Lashley, 1951; Lindblom, 1963) claim that time controls events whereas dynamic models predict a relative relation between time and space. Each of these models predicts a different relation between the acoustic measures of formant frequency and segmental duration. The most recent method described herein provides a sensitive index of speech deterioration which is both acoustically robust and phonetically systematic. Both acoustic and magnetic resonance imaging measures were used to describe the speech disturbance in two neurologically distinct groups of cerebellar ataxia: Friedreich’s ataxia and olivo-ponto cerebellar ataxia. The speaking task was designed to elicit six different prosodic conditions and four prosodic contrasts. All subjects read the same syllable embedded in a sentence, under six different prosodic conditions. Pair-wise comparisons derived from the six conditions were used to describe (1) final lengthening, (2) phrasal accent, (3) nuclear accent and (4) syllable reduction. An estimate of speech deterioration as determined by individual and normal subects’ acoustic values of syllable duration, formant and fundamental frequencies was used in correlation analyses with magnetic resonance imaging ratings.
The influence of phonological priming on variability in articulation
Authors: Babel Molly E. , Munson Benjamin
Published: September 2013

Previous research [Sevald and Dell, Cognition 53, 91–127 (1994)] has found that reiterant sequences of CVC words are produced more quickly when the prime word and target word share VC sequences (i.e., sequences like sit sick) than when they are identical (sequences like sick sick). Even slower production rates are found when primes and targets share a CV sequence (sequences like kick sick). These data have been used to support a model of speech production in which lexical items and their constituent phonemes are activated sequentially. The current experiment investigated whether phonological priming also influences variability in the acoustic characteristics of words. Specifically, we examined whether greater variability in the acoustic characteristics of target words was noted in the CV-related prime context than in the identical-prime context, and whether less variability was noted in the VC-related context. Thirty adult subjects with typical speech, language, and hearing ability produced reiterant two-word sequences that varied in their phonological similarity. The duration, first, and second formant frequencies of the target-words’ vowels were measured. Preliminary analyses indicate that phonological priming does not have a systematic effect on variability in these acoustic parameters.
The influence of semantic information on the acoustics of speech in noise
Authors: Patel Rupal , Syeda Mariam , Krauthammer Aviva
Published: September 2013

While there is a significant body of work on how people modify their speech patterns in the presence of noise, the role of semantic information on these acoustic modifications is not well understood. This study examined whether adult speakers of English differentially modify semantically salient versus nonsalient words within a sentence in the presence of noise. Participants were asked to produce a set of 20 sentences [from the Speech Perception in Noise List, Kalikow et al. (1977)], in each of five noise conditions; quiet, 60 and 90 dB SPL multispeaker conversation, and 60 and 90 dB SPL street noise. Five random repetitions per sentence were requested for each noise condition. The following acoustic cues were extracted for each word within an utterance: duration, average intensity, peak intensity, average fundamental frequency, and peak fundamental frequency. The ratios of these measures were then compared for semantically salient versus nonsalient words. While we expect to see an overall change in all of these prosodic cues for speech produced in noise (Lombard effect), semantically salient words may exhibit a greater ratio of change in some or all features.
The role of coda consonants in triggering speech errors: An ultrasound study
Authors: Pouplier Marianne
Published: September 2013

Recent speech-error research using articulatory data has shown that errors can often result in a phonologically illegal structure. These findings have been interpreted to mean that speech production is a fundamentally coordinative process. In speech errors, gestures can fall into grammatically illegal, albeit dynamically stable coordination modes. Shared gestural structures, such as identical consonants in the vicinity of the gestures affected by error, set up the conditions under which dynamically stable coordination modes can come to dominate over grammatical coordination patterns (e.g., Pouplier, 2003). This approach finds support in the often-observed phenomenon that a shared final consonant between two words will increase the likelihood of the initial consonants interacting. The present study uses ultrasound data of speech errors to investigate in what domains other than the coda shared gestural structure can trigger errors. Stimuli without coda consonants are employed to investigate whether errors on the initial consonants can be triggered by a shared vowel only. It is further examined whether the shared structure triggering errors can reside within the initial consonants themselves, e.g., when the initial consonants are complex, multigestural constellations that overlap in some aspects of their gestural composition. [Work supported by NIH RO1-DC01758.]
Spectral characteristics of speech with fixed jaw displacements
Authors: Solomon Nancy P. , Makashay Matthew J. , Munson Benjamin
Published: September 2013

During speech, movements of the mandible and the tongue are interdependent. For some research purposes, the mandible may be constrained to ensure independent tongue motion. To examine specific spectral characteristics of speech with different jaw positions, ten normal adults produced sentences with multiple instances of /t/, /s/, /∫/, /i/, /ai/, and /ɔi/. Talkers produced stimuli with the jaw free to vary, and while gently biting on 2- and 5-mm bite blocks unilaterally. Spectral moments of /s/ and /∫/ frication and /t/ bursts differed such that mean spectral energy decreased, and diffuseness and skewness increased with bite blocks. The specific size of the bite block had minimal effect on these results, which were most consistent for /s/. Formant analysis for the vocoids revealed lower F2 frequency in /i/ and at the end of the transition in /ai/ when bite blocks were used; F2 slope for diphthongs was not sensitive to differences in jaw position. Two potential explanations for these results involve the physical presence of the bite blocks in the lateral oral cavity, and the oromotor system’s ability to compensate for fixed jaw displacements. [Work supported by NIDCD R03-DC06096.]
Standards 101: The ASA Standards program
Authors: Schomer Paul
Published: September 2013

ASA serves as a standards developer under the auspices of the American National Standards Institute (ANSI). The Standards Program is organized through four technical committees (S1, S2, S3, and S12) and one administrative committee (ASACOS). S1 deals with physical acoustics, S2 deals with shock and vibration, S3 deals with physiological and psychological acoustics and S12 deals with noise. ASACOS is the ASA Committee on Standards. The program has three primary tasks: (1) development of national standards (ANSI Standards), (2) national adoption of international standards (ANSI NAIS Standards), (3) providing the USA input to the development of international standards (ISO and IEC Standards). At every level the main work is accomplished in Working Groups (WG) that are staffed by hundreds of volunteers, mainly ASA members from its various technical committees such as Noise, Physical Acoustics, Architectural Acoustics, Physiological and Psychological Acoustics, etc. Overall, the Standards Program involves more ASA members than does any other single function of the society except meetings. It is the biggest outreach function of ASA affecting the health, welfare, and economic well-being of large sectors of society. It is a main way the ASA diffuses the knowledge of acoustics and its practical application, perhaps the main way.
The roles of major international standards organizations
Authors: Cornish Steven
Published: September 2013

This review paper describes and analyzes the roles of the major international standards organizations, the International Organization for Standardization (ISO) and the International Electro-technical Commission (IEC). In particular, it analyzes the relationships of ISO and IEC with ANSI, CEN (including the ISO/CEN Vienna Agreement), and CENELEC. This paper also addresses recent developments to ensure the global relevance of ISO and IEC standards. Lastly, this paper addresses the myths, perceptions, and realities of European participation and potential dominance in ISO.
Characteristics of T phases from earthquake sources, or how earthquakes ‘‘talk’’ into the ocean
Authors: Okal Emile A.
Published: September 2013

We review the mechanisms by which earthquake sources within the solid Earth generate acoustic energy into the SOFAR channel. We examine individual cases involving both the relatively inefficient mechanism of ‘‘downslope conversion,’’ leading to T phases with low amplitudes and long durations, and efficient conversion at steep interfaces allowing direct penetration of the SOFAR, larger amplitudes, and shorter durations. We derive several ways to quantify T waves generated by an earthquake source. To avoid the saturation of their amplitude as source size grows, we use the concept of a T-phase energy flux (TPEF), which mirrors the radiated energy measured on conventional seismic body waves. TPEF is scaled to the seismic moment of the earthquake to define a parameter, gamma, characterizing the earthquake’s efficiency for T-phase generation. In another approach, we compare the amplitude of T-phase envelopes to the duration of their signal. The resulting discriminant has been proposed to identify earthquakes from explosions. We show that it varies for several categories of nonstandard earthquakes, notably those occurring in volcanic islands and events with slow rupture giving rise to large tsunamis. Finally, we discuss a few examples of T waves from underwater landslides.
Coupling of acoustic normal modes and seismo-acoustic surface waves in variable-depth shallow water
Authors: Godin Oleg A.
Published: September 2013

Marine sediments support Rayleigh-type surface waves which can propagate along the sea floor in arbitrarily shallow water and even on shore. At frequencies above a few Hertz, because of a strong attenuation of compression and especially shear waves in the sediments, the surface waves can significantly contribute to the acoustic field far from the shore only through their coupling to volume waves in the water. We study theoretically excitation of acoustic normal modes by the seismo-acoustic surface waves in a shallow-water waveguide with a sloping bottom. The role of bottom stratification is assessed by comparing acoustic fields generated by the Rayleigh wave, which is supported by a homogeneous elastic bottom, and by the fundamental mode of surface waves, which are supported by the bottom with a linear profile of shear rigidity. It is found that the coupling primarily occurs in the vicinity of a modal cutoff. The first normal mode is the one most strongly excited by the surface waves. For realistic values of geoacoustic parameters, the energy conversion rate can reach tens of percent, making the surface-to-volume wave conversion an efficient mechanism of the oceanic waveguide excitation by acoustic sources on shore or in very shallow water.
The feasibility of noninvasive image-guided treatments of brain disorders by focused ultrasound
Authors: Hynynen Kullervo , Clement Gregory , McDannold Nathan , Vykhodtseva Natalia , White P. Jason , Jolesz Ferenc A. , Sheikov Nickolai A.
Published: September 2013

Brain disorders, such as tumors, functional problems, etc., are difficult to treat and the invasive interventions often disturb surrounding brain tissue, resulting in complications. In addition, the delivery of therapeutic agents to the brain via the blood supply is often impossible because the blood brain barrier protects the brain tissue from foreign molecules. Our hypothesis has been that transcranial therapeutic ultrasound exposures can be delivered with an optimized phased-array system. We have demonstrated that highly focused therapeutic ultrasound beams can be accurately delivered through an intact human skull noninvasively. Furthermore, we demonstrated using ex vivo human skulls that we can use CT-derived information to predict the phase shifts required for correcting the wave distortion. We have also developed a method to focally disrupt the blood brain barrier without damaging the neurons in the targeted tissue volume. This may allow delivery of therapeutic or diagnostic agents into image-specified locations. Successful transcranial delivery of ultrasound in a clinical setting may have a major impact on the treatment of brain disorders in the future.
Design and testing of an ultrasonic system with integrated diagnostic and therapy modes
Authors: Lizzi Frederic L.
Published: September 2013

Our laboratories developed and tested a system integrating high-intensity focused ultrasound (HIFU) with diagnostic ultrasound procedures for aiming, delivering, and monitoring treatment exposures. The system employs 5-MHz, 5-element spherical-cap HIFU arrays with annular electrodes (for variable focusing) or strip electrodes (for inducing broad lesions of controlled width). Central apertures in these arrays house a coaxial diagnostic phased array (48 elements), interfaced with a custom digital system for visualization and RF echo acquisition. Several operational modes were investigated. A preexposure mode permits the HIFU focal point to be aimed at the desired location in B-mode images. It also assesses harmonic generation in the HIFU beam, using the diagnostic array to receive and spectrally analyze echoes from a short HIFU pulse aimed at targeted tissues. Radiation-force elastography uses the diagnostic array to monitor tissue displacements induced by brief exposures from the HIFU transducer; pre- and posttherapy data are compared to delineate mechanical alterations in lesioned volumes. Acquired pre- and post-RF data are also spectrally analyzed to map changes in scattering and attenuation indicative of lesion production. These modes have been successfully tested under in vitro conditions and are now entering use in animal studies aimed at treating cancer and cardiac diseases.
Feasibility of in vivo cardiac HIFU ablation
Authors: Fujikura Kana , Otsuka Ryo , Homma Shunichi , Muratore Robert , Ketterling Jeffrey A. , Lizzi Frederic L.
Published: September 2013

The potential for cardiac applications of HIFU remains unexamined. In order to create reproducible lesions in a beating heart, it is necessary to maintain focusing at a certain position within moving myocardial tissue. One technique is to use multiple short HIFU exposures (0.2 s) and synchronize them with an EKG signal and respiration. The left ventricular free wall (LVFW) of calf hearts were cut into 4-cm cubes, degassed in phosphate buffer saline (PBS), and heated to 37°C. An 80-mm-diam spherical-cap transducer with a focus of 90 mm was operated at a frequency of 4.67 MHz and a nominal focal point intensity of 26.9 kW/cm2. The transducer was coupled to the LVFW using degassed PBS. First, the effect of pericardial fat, focal depth, and temperature on lesion size was individually evaluated. Then the 0.2-s HIFU exposure was applied 10 to 30 times at 4-s intervals. The same HIFU transducer was applied to an open-chest canine LVFW with the same triggering protocol. Dimensions of all lesions were measured by visual examination of the fresh, unstained tissue. A histopathological examination of the lesion was also performed. The in vivo lesions were created in similar size to those in vitro.
Musical instrument technology of the 20th century
Authors: Wheeler Paul
Published: September 2013

This paper presents a brief history of the technical development of musical instruments during the 20th century. Starting with early electronic instruments (such as the Theremin—1917) invented prior to the organization of ASA, the history includes the development of electronic organs, synthesizers, and computer music. This paper provides an introduction to the session, giving a framework for the papers which follow in the session.
Relation between loudness and annoyance over time: Implications for assessing the perception of low-frequency noise
Authors: Hellman Rhona , Broner Norm
Published: September 2013

The literature suggests that, in contrast to loudness, annoyance increases over time. However, in these early measurements the annoyance exposure time usually did not exceed 120 s. In the current work, this temporal interval was extended to 3600 s (1 h). Within this time frame, both loudness and annoyance of low-frequency noise spectra containing dominant tones were measured at 12 temporal intervals by the method of successive magnitude estimation. Four noise spectra that evoked the largest annoyance-to-loudness ratios in previous reports were selected as stimuli. On average, after 1 h loudness declined by 8% and annoyance declined by 12.5% at moderate sensation levels (SL). By comparison, at 27-dB SL annoyance initially exceeded loudness by 51% up to 120 s and then, declined with time more slowly than loudness. These results indicate that, despite an 11-phon decrease in loudness level, the annoyance of a low-frequency steady noise with dominant tones below 50 Hz may initially increase over time. The annoyance increase may then be followed by a gradual annoyance decrease that mirrors the loudness decrease but at a slower rate. Taken together, the obtained relations imply, in accord with other data, that annoyance is not solely loudness based.
How to boost soundscapes with tax breaks—On the application of Henry George’s environmental economics to noise annoyance
Authors: Hehner Cay
Published: September 2013

The improvement of the characteristic soundscape in a given metropolitan area depends largely on a varied number of parameters not the least of which are economic. The way to sustain a large city not only economically responsible behavior patterns and activities are required, but ecologically viable ones as well. And, not coincidentally, if both patterns come into balance, a reduction of noise annoyance ensues. The cohesive set of measures that would provide the framework to ensure that the necessary economic activity is not antagonistic to (acoustic) ecology is provided by the US economist Henry George who advocated a comprehensive tax on land and all natural resources to replace eventually the bulk of all taxes checking production. New data will be provided in this paper to show the results of the application of a Georgist approach of eco-taxation to the improvement of sound quality and the reduction of noise annoyance.
Active reduction of acceleration sensitivity of quartz thickness shear resonators
Authors: Patel Mihir , Yong Yook-Kong
Published: September 2013

The piezoelectric quartz thickness shear resonator is a very important component in stable oscillators. The resonator is usually a rectangular or circular plate with electrodes on the top and bottom surfaces. When the resonator is subjected to acceleration, the inertial effects cause stresses and strains in the plate which in turn cause the resonant frequency to shift. A method is proposed to actively minimize the inertial stresses and strains by piezoelectric stiffening using a dc electric field bias across the electrodes. Finite element models are created to calculate the effects of acceleration on resonant frequency and compare the results with experimental data. The models are then used to calculate the effects of the dc electric field bias and demostrate the reduction of acceleration sensitivity. Results are shown for the AT- and SC-cut quartz resonators.
A really complicated problem: Auditory scene analysis
Authors: Yost William A.
Published: September 2013

It has been more than a decade since Al Bregman and other authors brought the challenge of auditory scene analysis back to the attention of auditory science. While a lot of research has been done on and around this topic, an accepted theory of auditory scene analysis has not evolved. Auditory science has little, if any, information about how the nervous system solves this problem, and there have not been any major successes in developing computational methods that solve the problem for most real-world auditory scenes. I will argue that the major reason that more has not been accomplished is that auditory scene analysis is a really hard problem. If one starts with a single sound source and tries to understand how the auditory system determines this single source, the problem is already very complicated without adding other sources that occur at the same time as is the typical depiction of the auditory scene. In this paper I will illustrate some of the challenges that exist for determining the auditory scene that have not received a lot of attention, as well as some of the more discussed aspects of the challenge. [Work supported by NIDCD.]
Auditory grouping in the perception of speech and complex sounds
Authors: Darwin Chris , Rivenez Marie
Published: September 2013

This talk will give an overview of experimental work on auditory grouping in speech perception including the use of grouping cues in the extraction of source-specific auditory information, and the tracking of sound sources across time. Work on the perception of unattended speech sounds will be briefly reviewed and some recent experiments described demonstrating the importance of pitch differences in allowing lexical processing of speech on the unattended ear. The relationship between auditory grouping and auditory continuity will also be discussed together with recent experiments on the role of grouping in the perceptual continuity of complex sounds.
Using spatialized sound cues in an auditorily rich environment
Authors: Brock Derek , Ballas James A. , Stroup Janet L. , McClimens Brian
Published: September 2013

Previous Navy research has demonstrated that spatialized sound cues in an otherwise quiet setting are useful for directing attention and improving performance by 16.8% or more in the decision component of a complex dual-task. To examine whether the benefits of this technique are undermined in the presence of additional, unrelated sounds, a background recording of operations in a Navy command center and a voice communications response task [Bolia et al., J. Acoust. Soc. Am. 107, 1065–1066 (2000)] were used to simulate the conditions of an auditorily rich military environment. Without the benefit of spatialized sound cues, performance in the presence of this extraneous auditory information, as measured by decision response times, was an average of 13.6% worse than baseline performance in an earlier study. Performance improved when the cues were present by an average of 18.3%, but this improvement remained below the improvement observed in the baseline study by an average of 11.5%. It is concluded that while the two types of extraneous sound information used in this study degrade performance in the decision task, there is no interaction with the relative performance benefit provided by the use of spatialized auditory cues. [Work supported by ONR.]
Stage analysis of auditory event perception: Posture in human gait
Authors: Pastore Richard E. , Solomon Matthew J. , Gaston Jeremy R. , Flint Jesse D. , Berens Melody S.
Published: September 2013

One ultimate goal of auditory research is to understand how we perceive natural events. In our conceptualization, there are three component stages to auditory event perception: the source event, the sounds produced, and perception of the event. The current study carefully examines each of these three components, and the inter-relationships among their properties. The auditory event class for the current study is human gait in a fixed environment (e.g., shoes, walking surface, room), with posture (upright versus stooped) manipulated within individual walkers. We analyze the source events in terms of both the anthropometrical and dynamic biomechanical properties of the individual walker, and sound in terms of temporal and spectral properties of sole and heel collisions with the floor. Finally, perception is evaluated in terms of accuracy in identifying source properties (e.g., posture). In addition to statistical analyses of source–sound, sound–perception, and source–perception relationships, the source–sound link is investigated using biomechanical modeling. These analyses provide a comprehensive picture of the relationships among our three conceptual stages as well as identifying what is, and is not, relevant to perception of this specific source event. [Research supported by NSF.]
On the ensemble variance of the energy of random plates loaded by point forces and distributed pressure fields
Authors: Cotoni Vincent , Gardner Bryce , Langley Robin
Published: September 2013

Statistical energy analysis (SEA) is used to predict the dynamic behavior of structural-acoustic systems at high frequencies. SEA predicts the mean vibrational energy over an ensemble of nominally equivalent systems. For example, a collection of individual cars coming off an assemble line would make an ensemble whose mean response is predicted by SEA. Recently a prediction of the variance of the energy in the SEA ensemble has been developed. At high frequencies where small changes in the system cause shifts in natural frequency that are larger than the average spacing of the natural frequencies, the variance becomes independent of the detailed nature of the differences between the members of the ensemble. This variance of energy can then be predicted with information available in an SEA model and with some few additional parameters describing the nature of the excitations and couplings. This new formulation is applied to an ensemble of random plates loaded by point forces and distributed pressure fields. An accurate prediction of the observed variance is demonstrated.
Voice-onset time and buzz-onset time identification: A ROC analysis
Authors: Lopez-Bascuas Luis E. , Rosner Burton S. , Garcia-Albea Jose E.
Published: September 2013

Previous studies have employed signal detection theory to analyze data from speech and nonspeech experiments. Typically, signal distributions were assumed to be Gaussian. Schouten and van Hessen [J. Acoust. Soc. Am. 104, 2980–2990 (1998)] explicitly tested this assumption for an intensity continuum and a speech continuum. They measured response distributions directly and, assuming an interval scale, concluded that the Gaussian assumption held for both continua. However, Pastore and Macmillan [J. Acoust. Soc. Am. 111, 2432 (2002)] applied ROC analysis to Schouten and van Hessen’s data, assuming only an ordinal scale. Their ROC curves suppported the Gaussian assumption for the nonspeech signals only. Previously, Lopez-Bascuas [Proc. Audit. Bas. Speech Percept., 158–161 (1997)] found evidence with a rating scale procedure that the Gaussian model was inadequate for a voice-onset time continuum but not for a noise-buzz continuum. Both continua contained ten stimuli with asynchronies ranging from −35 ms to +55 ms. ROC curves (double-probability plots) are now reported for each pair of adjacent stimuli on the two continua. Both speech and nonspeech ROCs often appeared nonlinear, indicating non-Gaussian signal distributions under the usual zero-variance assumption for response criteria.
Control of short lag VOT (voice-onset time) for voiced English stops
Authors: Berry Jeff
Published: September 2013

The American English stops /b/, /d/, and /g/ are produced with negative VOT (−150–0 ms) or short-lag VOT (0–30 ms). These two variants have been shown to occur with approximately equal frequency across speakers, although individual preferences are common. It has been hypothesized that the characteristic VOTs of short-lag stops are determined by relatively simpler articulatory control mechanisms than negative VOT variants. Specifically, if the vocal folds are approximated prior to constriction release, and intraoral pressure is vented only at the point of maximum constriction (without supraglottal expansion), the VOT will be determined by the venting process controlled by the time-varying constriction aperture. Thus, the release kinematics could account for effects of place of articulation and vowel context on short-lag VOTs. In the current work, the plausibility of this hypothesis is evaluated. The kinematics of constriction release gestures was examined from x-ray microbeam data. Descriptions of the time-varying geometries of constriction releases were input to a simple model of breath-stream dynamics and simulated VOT values were obtained. The descriptive and simulated data are consistent with the hypothesis that the characteristic durations of short-lag VOTs are determined by the venting process controlled by the supraglottal stop release gesture.
Time-reversal communication through a highly reverberant medium
Authors: Chambers David H. , Kent Claudia A. , Meyer Alan W.
Published: September 2013

An ultrasonic time-reversal array system is used to transmit communication signals across an aluminum slab with a large number of holes drilled through it. The hole pattern was designed to greatly attenuate the direct propagation path between each transmitter and receiver, thereby forcing the communication signal to be carried primarily by the random, scattered field. Four approaches to time-reversal communications [see Candy et al., J. Acoust. Soc. Am. Suppl. 1 114, 2367 (2003)] were used to establish clear (negligible symbol error) communication channels through the slab. Both point-to-point and array-to-point configurations were tested. Comparisons between these approaches are shown using both simulated and experimental measurements. [Work performed under the auspices of the U. S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under Contract No. W-7405-Eng-48.]
KauaiEx: Environmental effects on HF acoustic propagation with application to communications
Authors: Porter Michael B. , Hursky Paul , Siderius Martin , Badiey Mohsen , Caruthers Jerald , Hodgkiss William S. , Raghukumar Kaustubha , Rouseff Dan , Fox Warren , de Moustier Christian , Calder Brian , Kraft Barbara J. , McDonald Keyko , Stein Peter , Lewis James K. , Rajan Subramaniam
Published: September 2013

The Kauai Experiment (22 June–9 July 2003) was designed to study high-frequency (8–50 kHz) acoustics in a shallow-water waveguide. In contrast to much of the previous literature, emphasis was placed on multipath arising from multiple boundary interactions. Various participants were interested in different applications; however, a core theme was the role of the environment on acoustic communications. A great deal of effort was made to characterize the environment including the surface wave spectrum, 2D temperature structure along the propagation path, salinity, currents, and bottom properties. Most of these parameters were measured continuously over the 2 weeks of the experiment, providing information on the diurnal cycles. At the same time, extensive acoustic measurements were made using a variety of vertical line arrays, some of which spanned the entire water column. The acoustic measurements included channel probes to characterize the variation of the impulse response. These probes were interleaved with a variety of modulation schemes for communications including noncoherent methods such as MFSK (multifrequency shift keying), and DPSK (differential phase-shift keying), as well as coherent schemes such as QAM (quadrature amplitude modulation), OFDM (orthogonal frequency division modulation), and PPC (passive-phase conjugation) methods. Thus, the experiment provides a vast amount of information relating environment to acoustic propagation to modem performance. This talk will present an overview of key lessons learned to date.