bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of selective serotonin reuptake inhibitors on auditory processing
Authors: Gopal K. , Daly D. M. , Daniloff R. G. , Pennartz L.
Published: July 2002

In mammalian auditory systems, serotonergic and cholinergic systems modulate inhibition of GABA-ergic interneurons. Auditory processing has been evaluated in a patient who suffered withdrawn depression, lethargy, hypersensitivity to touch/pressure, light, and sound (but not taste/smell), and difficulty understanding speech. Treatment with fluvoxamine and fluoxetine, selective serotonin reuptake inhibitors, reversibly alleviated complaints. A sibling is similarly afflicted. Testing while medicated and at least 15 days after voluntary withdrawal (unmedicated; symptomatic without depression) revealed pure tone, SRT, word discrimination scores, tympanograms, and acoustic reflex thresholds within normal limits. Medicated SCAN-A results were normal; unmedicated results were disordered. Unmedicated, both otoacoustic emissions and ABR waves I, III, and V, were significantly larger, bilaterally. Central processing and vigilance were evaluated with sets of sparse acoustic stimuli. While medicated, responses to stimuli at each ear revealed well-defined transitions (p<0.0001) over 90 min. Vowels were homogeneous with controls; /ge/je/, /be/we/, and /be/de/ge/ were markedly shorter and consistently differed from normals (p<0.0001; the /de/ of /be/de/ge/ covered approximately 200 Hz). During unmedicated testing, responses to /ge/je/ began at medicated levels but approached chance levels over 10 min; responses to /be/we/ were consistent (and aberrant) throughout.
The changing loudness aftereffect following adaptation to visual motion-in-depth
Authors: Kitagawa Norimichi
Published: July 2002

After exposure to a sound increasing or decreasing in level, a steady sound is perceived as changing loudness in the opposite direction. This study shows that this auditory aftereffect of changing loudness results from adaptation to a visual motion-in-depth, too. A visual adapting stimulus was a square of fixed size which changes in retinal disparity, so that it appears to move toward or away from the subject. The increasing or decreasing 1000-Hz tone was used as an auditory adaptation stimulus. The magnitude of the aftereffect was measured after adaptation to each of the following conditions: (a) auditory stimulus only; (b) auditory and visual stimuli in the same direction (increasing and moving toward, or vice versa); (c) auditory and visual stimuli in the opposite direction (increasing and moving away from, or vice versa); and (d) visual stimulus only. The aftereffect was observed in any of these conditions, and even in condition (d). The magnitude of the aftereffect reached the maximum in condition (b). The aftereffect in condition (c) was almost the same as that caused in condition (a). These results suggest that the mechanism processing the change in level in auditory system responds to the visual motion-in-depth.
Conductive hearing losses caused by static pressure differences in the ear
Authors: Kringlebotn Magne
Published: July 2002

The frequency characteristics of sound transmission loss in the ear have been measured as a function of the static pressure difference across the tympanic membrane as well as the static pressure difference between the inner ear fluids and the middle ear. The measurements have been performed on cadaver ears from Norwegian cattle. On average, for an increasing static overpressure in the ear canal up to 10 cm of water in magnitude, the transmission loss below 1 kHz increases rapidly to about 13 dB for positive overpressures and to about 9 dB for negative, and then more slowly to about 28 and 26 dB at 60 cm of water. At higher frequencies the transmission losses become smaller, but are markedly different for positive and negative overpressures in the ear canal. The sound transmission in the ear is little influenced by a pressure increase in the inner ear fluids.
Modal overlap and dissipation effects in a fuzzy structure containing a continuous master element
Authors: Drexel Michael V. , Ginsberg Jerry H.
Published: July 2002

This work was prompted by a study by Strasberg [J. Acoust. Soc. Am. 102, 3130(A) (1997)] in which a large suspended mass had numerous small spring–mass–damper systems attached to it. The system parameters in his model were selected such that the isolated natural frequency of each attached system was close to the natural frequency of the isolated master structure. Strasberg found when an impulse excitation is applied to the master structure, the critical issue is the bandwidth of the isolated attached systems in comparison to the spacing between the natural frequencies of those systems. Modal overlap, which corresponds to bandwidths that exceed the spacing of those frequencies, was shown to lead to an impulse response that decays exponentially. In contrast, light damping leads to an impulse response that consists of a sequence of exponentially decaying pulses, due to delayed energy return from the subsystems. The present work explores these issues for continuous systems by replacing the one-degree-of-freedom master structure with a cantilevered beam. The system parameters are selected to match Strasberg’s model, with the suspended subsystems placed randomly along the beam. The beam displacement is represented as a Ritz series whose basis functions are cantilever beam modes. The coupled equations are solved by a state–space eigenmode analysis that yields a simple closed-form representation of the response in terms of the complex eigenmode properties. The continuous fuzzy structure is shown not to display the transfer of energy between the master structure and the substructures exhibited by the discrete fuzzy structure, apparently because the attachment points move asynchronously due to the spatial dependence of the beam’s displacement.
Maximum likelihood methodology applied to empirically described probability distributions of speech movement data
Authors: Kollia H. Betty , Jorgenson Jay
Published: July 2002

In previous work [J. Acoust. Soc. Am. 102, 3164–3165(A) (1997)] an analysis of speech production data [from Kollia et al., J. Acoust. Soc. Am. 98, 1313–1327 (1995)] was initiated using Maximum Likelihood methodology in order to introduce a more realistic description of the behavior of the articulators. In this way the kinematic measures are described via natural probability distributions determined by the data set itself. These results show much smaller confidence intervals when the possible values of these parameters are described as lying in a bounded range (versus a normal distribution) with a diminishing likelihood of observing a data point farther from (than closer to) the mean. In this study the data are used to estimate the probability distributions (one for each value of the independent variable). The methodology employed, the family of probabilty distributions described by the data (one family for velocity-displacement data and another family for displacement-displacement data), and the resulting statistical analysis via maximum Likelihood methodology are reported on. Finally, the entire analysis is described in terms of what can be viewed as stochastic linear regression analysis with general error terms and the method for further analysis of error terms for comparable data. [Work supported by NSF.]
Emphasized versus unemphasized /aJ/: Jaw, tongue, and formants
Authors: Erickson Donna , Fujimura Osamu , Dang Jianwu
Published: July 2002

This study documents the relation between formants and jaw/tongue dorsum position in the context of emphasized–unemphasized monosyllabic words with the vowel /aJ/ in read speech. Articulatory and acoustic data were obtained by x-ray microbeam at the University of Wisconsin (courtesy, J. Westbury) from three American English speakers for about 300 words per speaker. Emphasized as opposed to unemphasized words are characterized by higher F1, lower F2, and lower jaw and tongue dorsum. Preliminary analysis of one speaker using a one-way ANOVA indicates the differences are statistically significant. For one speaker for emphasized vowels, an increase of lowering minima by 2 and 3 mm, respectively, for jaw and dorsum results in a 100-Hz change in F1 and F2 each. The biomechanical mechanism relating dorsum position to jaw position will be discussed, in conjunction with the recent C/D-model interpretation of jaw movement and durational change as the consequence of syllable magnitude control [O. Fujimura, B. Pardo, and D. Erickson, ESCA (1998)]. [Work supported by NSF SBR-951199B and ATR/HIP, Kyoto, Japan.]
Tongue–jaw trade-offs and naturally occurring perturbation
Authors: Kroos Christian , Geumann Anja , Hoole Philip
Published: July 2002

Experimentally induced perturbation of speech shows that articulatory resources are flexibly marshalled to achieve phonetically defined goals. Are such key principles of motor control observable in unconstrained speech? Two sources of natural perturbation were considered: coarticulation and loud speech. Alveolar consonants were investigated. The expectation was that V-to-C coarticulation and different loudnesses would cause consonantal jaw position to vary. Would the tongue use compensation to keep vocal tract constriction relatively constant? Would trade-off patterns vary over consonants sharing place of articulation but differing in manner? One preliminary hypothesis, motivated by pilot experiments, was that trade-offs would be most apparent in acoustically sensitive sounds such as sibilants. This was not confirmed. Jaw position was so precise for sibilants that no lingual compensation was required. Probably the teeth function here as an active articulator. Nevertheless, clear patterns in overall magnitude of variability in the alveolar consonants were observed. For both jaw and tongue, variability increased from fricatives via stops to the lateral (and nasal). Within the tongue these sound-specific effects were more pronounced for tongue-back than tongue-tip. Even such simple facts await a coherent explanation. To this end, discussion will focus on the acoustic properties of these sounds. [Work supported by DFG Ti69/31.]
Contribution of sound spatialization to audio-visual quality in videoconferencing
Authors: Chateau N.
Published: July 2002

Two experiments were conducted to evaluate the contribution of sound spatialization to audio-visual quality in videoconferencing. The first experiment aimed at measuring the threshold of perception of a spatial mismatch between a sound and a related image. Twenty-four subjects had to judge whether the sound of videoconference samples emanated or not from the same direction in the horizontal plane as the related image. The actual spatial discrepancies ranged from 0 to 25 by 5° steps and the sound had three distinct bandwidths (300–3400, 100–7000, 100–15000 Hz). In a second experiment, subjects had to judge the audio-visual quality of the same stimuli on a five-point categorical scale (ACR). Results of the first experiment indicate that the 75% threshold of perceived spatial mismatch is reached between 5 and 10° and is independent of sound bandwidth. Results of the second experiment show that audio-visual quality is influenced by sound bandwidth [F(2,46)=110.94, p<0.001], the angular separation [F(5,115)=48.64, p<0.001], and the interaction between these two factors [F(10,230)=10.55, p<0.001]. Combination of the results of the two experiments highlight that for a given bandwidth, perceived audio-visual quality is linearly dependent (Pearson’s r2>0.84) of perceived spatial audio-visual coherence.
Multimedia database of musical instrument sounds
Authors: Kostek Bozena , Suchomski Piotr
Published: July 2002

The presented study addresses the broad problem of automatic recognition of musical instrument sounds. Many applications of the algorithms dealing with these tasks may be foreseen. Nowadays, with the rapid growth of electronic libraries and databases such as those found on the Internet, the possible application may be to search a musical database for the sounds of chosen instruments or for musical tunes. For the purpose of the experiments that deal with instrument sound recognition, a multimedia database of musical instrument sounds was engineered. It encompasses: basic information on musical instruments, including playing techniques, description of parameters extracted from sound, images, sound samples within the instrument musical scale, exemplary musical phrases played by a given instrument, time- and frequency-domain representation of sounds for the whole instrument musical scale, and tables containing the sound parameter values. The database makes it possible to create various kinds of charts and printed reports for all parameters, enables SQL-based queries, and shows a collection of linked HTML pages. The engineered multimedia database was used in musical instrument timbres and musical phrases recognition experiments conducted by one of the authors, employing some computational intelligence methods as neural networks, fuzzy logic, and rough sets.
Application of ultrasound reflection tomography for nondestructive evaluation of objects with a complex geometry
Authors: Kažys Rymantas J. , Mažeika Liudas , Jasiūnienė Elena
Published: July 2002

In the case of solid objects with complex geometry, conventional ultrasound tomography techniques tend not to be efficient enough. The objective of the paper is the development and experimental verification of an ultrasound tomography approach suitable for objects with non-flat boundaries. The reconstructed images in ultrasound reflection tomography usually are imperfect because of ultrasound wavefront curvature, which is significantly affected by wave refraction and mode conversion phenomena at the boundaries. In order to achieve better resolution of reconstructed images in the ultrasound reflection tomography, the curvature of the wavefronts has to be known and taken into account performing backprojection. Ultrasonic wavefronts were reconstructed from measured ultrasonic wave parameters. Obtained results were taken into account performing backprojection in the ultrasound refection tomography. When the curvature of the wavefront is known, the shape and the size of the defects can be reconstructed with greater accuracy. In order to determine accuracy of the proposed method, computer simulations and experimental measurements have been carried out and sources of possible errors were detected. From the results presented it can be seen that the method proposed increases accuracy of the ultrasonic reflection tomography.
Role of acoustics in oceanographic monitoring of the Arctic ocean
Authors: Sabinin Konstantin D.
Published: July 2002

Acoustic soundings of the Arctic ocean (AO) along some tracks in crucial regions of the ocean can provide satisfactory information for the monitoring of the most important oceanographic features of the AO waters, namely, the heat content of the Atlantic water layer in the AO and the upper ocean salinity. Optimal location of the acoustic tracks for monitoring of the heat content space-time variability is discussed. It is shown that the remote sensing of the upper ocean salinity by acoustic tomography (acoustic halinometry) is quite possible since changes in the sound speed in the upper AO are due to changes in salinity, while temperature here is nearly always close to the freezing point. The results of the acoustic halinometry numerical modeling are demonstrated using oceanographic data obtained in the Amundsen Basin of the AO. The effect of a combination of different in situ and remote sensing measurements for monitoring of the salinity flux through the Bering Strait is discussed. [Work supported by RFFR and CRDF.]
On the adiabaticity of acoustic propagation through nongradual ocean structures
Authors: Shang E. C. , Wang Y. Y. , Gao T. F.
Published: July 2002

The adiabaticity of acoustic propagation is attractive for acoustic field description, data interpretation, and inverse scheme consideration. It is well known that, in general, the adiabaticity can be held for gradual medium, and the criteria of adiabaticity have been given by Milder (1969), Brekhovskikh (1973), and Brekhovskikh and Lysanov (1982), respectively. In this paper, the adiabaticity of acoustic propagation through nongradual ocean structures is investigated both theoretically and numerically. Here, the term nongradual means that the scale of the ocean structure M is smaller than the modal interference distance Dmn between mode ‘‘m’’ and mode ‘‘n.’’ Two examples of the nongradual ocean structures are discussed: (1) polar frontal zone with a width of about 2 km, and (2) internal solitons in shallow water with a width about 0.8 km. Comments on the criteria given by Milder and Brekhovskikh will be addressed. [Work supported by ONR and NOAA.]
Energy-conserving and reciprocal solutions for higher-order parabolic equations
Authors: Mikhin Dmitry Yu.
Published: July 2002

Conservation of sound energy in nonabsorbing media and acoustical reciprocity in stationary fluids at rest are the fundamental properties of the acoustic field. Preserving these properties in parabolic approximations is essential for accurate modeling of sound propagation in shallow-water environments. Recently Godin proposed a family of wide-angle parabolic equations (PE’s) for motionless fluid which are energy conserving, reciprocal, and allow improved description of mode coupling without adversely affecting phase accuracy. For moving media, a generalized Claerbout PE was also derived. Its solutions preserve the acoustic energy in the absence of dissipation and satisfy the flow-reversal theorem (FRT), which is an extension of reciprocity principle to moving media. The report presents a numerical scheme for solving the proposed PE’s. The algorithm preserves the conservational properties of the original (pseudo-)differential equations. Implicit finite-difference solutions satisfy discrete analogs of the energy conservation law and FRT. The developed computer model is applied to simulate acoustic tomography of oceanic currents. Inversion follows the method of matched nonreciprocity tomography. Flow reconstruction in range-dependent coastal environments is analyzed under the presence of small-scale uncertainties in bottom topography. [Work supported by CRDF, INTAS, and RBRF.]
Measurements of anechoic room characteristics
Authors: Milosevic Miroslava A. , Ciric Dejan G.
Published: July 2002

A simple measurement system with a computer as the main unit is developed for the measurements of the characteristics of an anechoic room, such as measurements of the sound-pressure decay in space, the sound-pressure decay in time, and the sound insulation. The measurements are performed in two steps. The room response signals are first recorded and stored in the PC memory. Then, these signals are processed by designed software depending on the type of measurement. The departure of sound-pressure decay in space from the ideal characteristic is observed. The sound-pressure decay in time is obtained by the integrated-impulse method using the maximum-length sequence technique. The sound insulation is measured only for a specially designed door between the anechoic and the control room because of its insulation, which is rather low in regard to the other parts of an anechoic room. The measurements performed in the anechoic room of the Faculty of Electronic Engineering in Nis have shown that the departure of sound-pressure decay in space from the ideal characteristic is rather below the limit of 1 dB in frequency range from 50 Hz upward. The door sound insulation is above 55 dB.
Four-microphone-array measurements combined with geometrical room acoustic simulation technique
Authors: Becker Jörg , Sapp Markus , Schmitz Oliver
Published: July 2002

For a revision of the acoustics of enclosures it is important to analyze the existing acoustical mechanisms. Therefore, measurement of room impulse response functions is a usual standard. The temporal progression of the incident sound can be determined from these impulse responses. Single number quantities can be evaluated, too. However, the knowledge of the direction of the first reflection is also of prime importance. Computer simulation of the room acoustic is a powerful tool to evaluate these directions but it is only reasonable if the geometry of the room is well known. Often it is difficult to get detailed information of the geometry, especially if there are curved walls. This paper focuses on the evaluation of spatial information of sound fields with a four-microphone-array measurement system and the post-processing with algorithms taken from geometrical room acoustic simulation. With multidimensional sound field analysis it is possible to get the direction of the important reflections. Virtual sound sources can be calculated. With a back tracing algorithm the history of higher-order reflections can be determined or the geometry of the room model and the results of computer simulation can be verified by a comparison of measured and calculated VSS.
Therapeutic ultrasound—An historical overview
Authors: ter Haar Gail
Published: July 2002

Ultrasound was used with therapeutic intent long before its potential as an imaging modality was contemplated. Initially it was thought of as acting solely through its heating ability, but more recently there has been scientifically convincing evidence that beneficial effects can be induced in the absence of biologically relevant bulk temperature rise, thus indicating that nonthermal mechanisms may also play a part in ultrasound treatments. Apart from the high-intensity, surgical uses (operating at peak intensities around 2 kW cm−2), ultrasound has been applied amongst other things to promote wound healing, to stimulate bone repair, to accelerate healing in tendon injuries, and as a thrombolytic agent. The majority of therapeutic ultrasound techniques operate at intensities of 500 mW cm−2 or less (spatially averaged intensities). It is interesting to compare the different techniques and modes of delivery in an attempt to understand the mechanisms of action that produce beneficial biological effects.
Ultrasonic technique for the investigation of structural properties of biological fluids
Authors: Voleišis Algirdas , Kažys Rymantas J. , Mažeika Liudas , Šliteris Reimondas , Voleišienė Birutė
Published: July 2002

Biological fluids are specific objects for acoustical investigation due to the wide spectra of relaxation processes, especially nonstationary fluids such as blood during its coagulation process. The proposed method combines measurement of ultrasound attenuation over a frequency range and, ultrasound velocity dispersion being negligible, precise measurement of velocity variations at fixed frequency. In the dynamic spectroscopy method the wideband ultrasonic signal transmitted through the media is digitized with a sample rate of 200 MHz, averaged, and processed by a PC. Ultrasound absorption frequency dependency with intervals of 1 min is determined from amplitude spectra. Using small volume (1 ml) cell with multiple reflections, in the range of 2–17-MHz, diffraction corrections and ultrasonic attenuation were determined in low-absorptive standard liquid, conservative, and native coagulating blood. The clot formation process in the native blood is also monitored at frequencies 5 or 10 MHz using the time-of-flight method with the acquisition of the results. In the cell of 0.2 ml volume sensitivity of 0.2 ns is achieved. Cell parameters and influence of the pulse bandwidth are analyzed. According to the ultrasound velocity variations, four typical blood coagulation phases were observed during 30 min, less expressed being the first phase (0–2 min).
A parametrized model of psychoacoustical roughness for objective vehicle noise quality evaluation
Authors: Hoeldrich Robert , Pflueger Martin
Published: July 2002

In the assessment of vehicle interior noise quality, sound characteristics caused by modulation play an important role because they contribute significantly to the perceived annoyance. The proposed parameterized model for the sensation of psychoacoustical roughness was developed as part of a research program with the aim of establishing an on-board analysis system for vehicle interior noise quality based on objective sound parameters. The roughness model can be adjusted by model parameters to calculate versions of roughness, thereby accentuating different psychoacoustical assumptions. The model is based on the excitation-time pattern of the interior car sound which is recorded using an artificial head system. From the excitation-time pattern, a set of specific roughness parameters in overlapping critical bands is obtained utilizing different weighting functions for the envelope spectrum in each band and various correlation methods between adjacent bands. The specific roughness parameters in critical bands are superimposed in several ways, resulting in a set of modulation parameters. The model was successfully tested not only in predicting roughness assessments, as reported in a companion paper, but it also proved to result in one valid objective parameter for the description of vehicle interior noise quality.
RPG diffusers used for noise screening applications
Authors: Bertellino Franco G. M. , Stantero Luca , Massacesi Antonio
Published: July 2002

The paper deals with the performances of noise barriers designed using the reflecting phase grating diffuser theory, which is based on the interference produced by slots of different depths. Usually such structures are used to improve sound diffusion in recording rooms, but they can be suitable also to reduce highway and railway noise for their capability of scattering sounds. A theoretical approach has been used to project their shape using a self-developed VB application, able to predict the scattered sound distribution as well. The theoretical results have been verified with a physical scale model in an anechoic room: insertion losses in several configurations have been measured, together with intensity measurements of the scattered acoustic field. Experimental results seem to match quite well those obtained using the simulation program.
Application and extension of acoustic holography techniques for tire noise investigations
Authors: Augusztinovicz Fulop , Gransst Jssnos , Mssrki Ferenc , Hendricx Wim , Van der Auweraer Herman
Published: July 2002

Acoustic holography (AH) is a powerful measurement tool for the investigation of complex sound radiation problems. Enabling detailed source investigations based on noncontact measurements, it is especially useful for the investigation of rotating noise sources such as automotive tires. Nevertheless, conventional AH techniques are burdened by the constraint that the source is assumed to be planar. Based on a detailed measurement series which was performed on a laboratory roller bench, the radiation of a test tire was investigated by means of AH. It was found that even though valuable information could be obtained, the most important forward and backward radiation of the tire is difficult to tackle in this way. Another approach of the radiation analysis is offered by developing an inverse BEM method. Different implementations of the method have been worked out and tested, based mainly on the sysnoise and matlab software packages. The technique is applied to experimental tire mock-ups as well as to real-life tire measurements. The practical application and inherent limitations of the technique are also discussed.
Standardization in the field of traffic noise—An overview of current projects
Authors: Schober Ulrich
Published: July 2002

Standardization of vehicle noise measurement procedures is an important instrument for achieving comparable and reproducible measurement results and therefore to provide means for minimizing traffic noise in the long run. In the International Organization for Standardization Technical Committee ISO/TC 43 ‘‘Acoustics’’ and other ISO/TCs many standards about noise emission measurements on all kinds of vehicles including aircraft, and about tire/road noise effects and road surface characteristics are currently under preparation in several working groups. Some standards are under revision to bring them in line with the advances in vehicle technology, other standards are prepared due to the needs from vehicle manufacturers and environmental protection representatives. The lecture presents ongoing developments in important projects and emphasizes their joint aspects and differences. Examples: (i) Revision of ISO 362 about noise measurement on accelerating cars and motorcycles which is important for type testing. (ii) Project about measurement of tire noise. (iii) Project about the influence of road surfaces on traffic noise to facilitate acoustical characterization of road surfaces (ISO 11819 series). (iv) Revision of ISO 3891 about aircraft noise. (v) Projects about noise emission measurements on vessels (revision of ISO 2922) and small recreational craft (new ISO 14509). (vi) Revision of ISO 3095 about noise emission of railbound vehicles.
Modeling the propagation of traffic noise in topographically modified atmospheric environments
Authors: Heimann Dietrich
Published: July 2002

A meteorological mesoscale model is used to simulate the time-dependent distribution of temperature and the corresponding development of autochthonous slope-wind systems in a narrow two-dimensional valley during the course of a cloud-free day. Further simulations consider the topographical modification of allochthonous airflow across the valley. A numerical sound particle model was designed to cope with both the uneven terrain and the inhomogeneous meteorological environment. The acoustical model takes up the simulated meteorological fields and calculates the propagation of noise which originates from a steady source (road or railway) in the valley. The coupled modeling system ensures consistency of topography, meteorological parameters, and the sound field. The temporal behavior of the sound-pressure level across the valley is examined. The results show remarkable, meteorologically induced variations of the sound level during the course of a cloud-free day. In addition, it is shown how the location of a planned traffic way can be optimized with respect to minimum noise impact in the valley [D. Heimann and G. Gross, Appl. Acoust. (in press)].
A European noise indicator
Authors: van den Berg Martin
Published: July 2002

The European Commission installed five working groups with tasks to advise the Commission on a future European noise policy. The first working group, chaired by the author, was required to advise on European noise indicator. From research that was carried by INRETS [study related to the preparation of a communication on a future EC noise policy, LEN Report nr 9420 Lyon (1994)] it was clear that a large variety exists in noise indicators and calculation methods, which makes it difficult to compare efficiency of abatement measures. According to the time schedule the working group is to produce its final report in February 1999. In the presentation the conclusions of the working group will be discussed.
EU’s future noise policy: Progress report of WG Dose/Effect
Authors: Lambert Jacques
Published: July 2002

In order to assist the preparation of the EU’s future noise policy, WG 2 (Dose/Effect) has launched a work program that will: provide dose/effect relationships for annoyance, sleep disturbance, speech interference (and other effects if necessary), provide proposals for noise indices, define needs on dose/effect research and play an active role in the initiation and coordination of that research, make proposals for the dissemination of information to the public and to authorities (national, local and regional), and make a proposal for the setting of targets by authorities making use of harmonised dose/effect relationships. An inventory of existing material is now available as well as an identification of research needs (March 1999). A position paper will be delivered to the European Commission by 2002. It will focus on thresholds and dose-effect relationships related to transportation noise (road, rail, and aircraft), industrial noise, entertainment and recreational noise, on the setting of targets for the point of view of health effects, and dissemination of gathered information.
Acoustic tomography as a remote sensing method inside the atmospheric surface layer
Authors: Ziemann Astrid , Arnold Klaus , Raabe Armin
Published: July 2002

Acoustic travel time tomography will be applied on the atmosphere to directly provide spatially averaged values of meteorological quantities (temperature and wind field) which are needed for the evaluation of numerical models as well as to complete in situ point measurements and conventional studies of the atmospheric surface layer over natural surfaces. Sound waves propagate through the atmosphere with different sound velocities according to the distribution of air temperature and wind vector and become, therefore, an information carrier about the medium properties. In the presented study acoustic travel time data were measured between sources and receivers placed around an array of 200×260 m2 as initial values for the tomographic reconstruction. Thereby, a frequently applied procedure of ray tomography, the simultaneous iterative reconstruction technique, characterized by simple handling and small computational requirements, was used. Additionally, a special system of equations for the isolation of the temperature and wind influence on the sound speed was solved. To estimate the sound ray propagation and to simulate acoustic travel times during various meteorological conditions a ray tracing model based on a modified version of Snell’s law corresponding to the influence of wind vector will be introduced.
Sodar-derived vertical profiles of the parameters of atmospheric turbulence
Authors: Shamanaeva Lyudmila G. , Bogushevich Aleksandr Ya.
Published: July 2002

The vertical profiles of the structural characteristics of temperature and wind velocity fields and longitudinal and transverse structure functions of the wind velocity field measured with the Zvuk-2 three-channel Doppler sodar are presented for altitudes of 75–535 m above the ground with a 20-m altitude resolution. The sodar operated at a frequency of 1700 Hz, its pulse repetition period was 10.5 s, and its pulse length was 150 ms. One transceiving antenna was pointed vertically and two others were tilted at angles of 20 degrees from the vertical in orthogonal planes. Backscattered signal power was additionally measured. Sodar data were interpreted using the iterative algorithm considering the excess turbulent attenuation of a sodar signal. Sodar-derived structural characteristics were compared with simultaneous measurements by an ultrasonic anemometer/thermometer. The structure functions of the wind velocity field were calculated from long series of observations of vertical profiles of the wind velocity vector. At night when the wind shear was observed the longitudinal structure functions below it were strongly suppressed, whereas above the wind shear they sharply increased. Under conditions of daytime convection the structure functions first increased with the separation between the observation points and then saturated.
Experimental method of acoustic tomography of the atmospheric surface layer
Authors: Arnold Klaus , Ziemann Astrid , Raabe Armin
Published: July 2002

Acoustic tomography is proposed as a technique for remote monitoring of near surface temperature and wind fields. An experimental method is presented which provides area-averaged values of the demanded meteorological parameters. In this study travel time tomography was used by measuring the travel time of a signal at a defined propagation path. In such a system a number of sources simultaneously transmit an acoustic signal (sine oscillation) which is detected at a number of receivers. The travel time of each signal was estimated by cross correlation between the received and the transmitted signal. Each peak of the cross correlation is associated with a separate ray path and the delay time corresponds to the travel time of the transmitted signal. The travel time data were inverted to obtain estimates of the meteorological parameters. A field experiment was carried out in autumn 1997 at the test site Melpitz near Leipzig to provide the input data for the tomographic reconstruction. Six sources and four receivers were positioned at an array of 200×260 m2. Derivations of area-averaged values result from inversion of the single values of travel time for all ray paths.
Prediction and measurement of the transmission coefficients of transversely isotropic porous plates
Authors: Aknine Achour , Castagnède Bernard
Published: July 2002

The prediction of the transmission coefficients is based on the Biot theory of elastic waves propagation in fluid-saturated porous solids. An elastic wave impinging upon an interface between a fluid and a fluid-saturated anisotropic porous solid can generate two compressional waves (one fast and one slow) and two shear waves (one horizontal and one vertical) in the porous medium. The motion in the porous plate results in coupled differential equations involving separate displacements in the skeleton and the saturating fluid. The wave speeds of the propagation modes in the porous medium were determined by seeking the solution of the equations of motion as plane acoustical waves. The transmission coefficients were finally obtained from boundary conditions at the interfaces between the fluid and the porous plate. They were experimentally determined, in the case of a porous corundum ceramic plate immersed in water, by using an ultrasonic immersion technique. The agreement between the predicted and measured transmission coefficients versus the angle of incidence for this plate is acceptable and has been achieved using adjustable and fitted parameters.
Competition between space and time in the auditory system
Authors: Carlyon Robert P. , Demany Laurent
Published: July 2002

Listeners were presented with a dichotic 1-s bandpass-filtered (3900–5300 Hz) pulse train at a rate of Fr Hz in one ear and 2Fr in the other, against a noise background. Each pulse in the Fr train was simultaneous with a pulse in the other ear. Listeners adjusted the ILD of a bandpass-filtered noise to match the perceived location of one pulse train, and then adjusted the rate of a diotic train, presented at that ILD, to match its perceived rate or pitch. At low rates (e.g., Fr=1 Hz) they heard pulses alternating between the midline and the ear receiving the 2Fr train, with the perceived rate in each location approximately equal to Fr. At high rates (e.g., Fr=100 Hz) they heard a pitch of Fr in one ear and 2Fr in the other. At intermediate rates (12<Fr<50 Hz) a duplex region occurred, whereby the Fr train was heard close to the midline but where the 2Fr train was perceived at its ‘‘correct’’ rate. This duplex region, combined with other results, argues against simple schemes in which binaural localisation occurs either entirely ‘‘before’’ or ‘‘after’’ sequential binding processes.
Loudness recalibration and complex tones
Authors: Mapes-Riordan Dan , Yost William A.
Published: July 2002

Loudness recalibration occurs when a loud (recalibration) tone at frequency f1 precedes quieter test tones at frequencies f1 and f2. Previous experiments [Mapes-Riordan and Yost, J. Acoust. Soc. Am. 101, 3170(A) (1997)] have shown that the recalibration tone can decrease the loudness of the test tone at f1 by more than 6 dB. The current experiments addressed loudness recalibration when the test signal and/or recalibration signal was harmonic complex tones. In the first experiment an adaptive tracking procedure measured the equal loudness point between a harmonic complex and a pure tone. In the recalibration conditions, the loudness comparisons were preceded by a recalibration signal consisting of various combinations of frequencies contained in the harmonic complex, or by a pure tone corresponding to the pitch of the missing fundamental. In the second experiment, listeners were asked to adjust the level of a single harmonic (f3) in a harmonic complex (f1−f5) until it was heard as a separate tone in conditions with and without a recalibration tone at f3. The results of these experiments will be discussed in terms of the loci of loudness recalibration relative to perceptual stream formation. [Work supported by a NIDCD Program Project Grant.]
Burst spectra and place of articulation in read speech
Authors: McGowan Richard S.
Published: July 2002

The burst spectra of voiceless stop releases are examined with a set of wide-band filters. These spectra are selected from one male speaker and one female speaker of American English, each reading from a list of 100 sentences. A set of rules is proposed for inferring place-of-articulation based on filter amplitudes obtained from a training set of utterances. The formulation of these rules is aided by segregating the data according to speaker and according to the second formant frequency at voice onset of the following vowel. This work is part of a project to infer articulatory movement from speech acoustics. [Work supported by the NIH through Grant No. DC-01247.]
Effect of frequency modulation of F0 on the accuracy of formant frequency matches
Authors: Dissard Pascal , Darwin Chris J.
Published: July 2002

Listeners adjusted the formant frequency of a one-formant complex sound to match the timbre of a similar fixed sound (formant frequency =1100 or 1200 Hz). On each trial the two sounds’ fundamental frequencies (F0) were in the ratio 1 : 1.13. In half the blocks the sounds were on low fundamentals (80 and 90.4 Hz), giving unresolved harmonics in the region of the formant peak; in the other half of the blocks the F0 was high (221.2 and 250 Hz), giving resolved harmonics near the formant peak. Orthogonal to this manipulation the F0 was either unmodulated for both sounds, or had a frequency modulation (FM) of 6 Hz and 3% depth. Data from seven listeners showed that, with no FM, matches are more variable within each listener for sounds with resolved than for sounds with unresolved harmonics, but that this difference disappears with FM. The result provides evidence that frequency modulating F0 improves listeners’ ability to estimate a formant frequency that is cued by resolved harmonics. [Work supported by EPSRC Grant No. GR/L03422.]
Ocean bottom seismic noise (1–10 000 s)
Authors: Montagner Jean-Paul
Published: July 2002

There is now a good consensus in the geophysical scientific community of the necessity to install broadband seismic stations on the ocean bottom in order to improve our knowledge of the deep Earth dynamics. However, it is necessary to first investigate the level of seismic noise (0.01–10000 s) and to compare it with the expected amplitude of seismic signal due to earthquakes. During the French pilot experiment SISMOBS/OFM (28 April–11 May 1992) in the Atlantic Ocean, two sets of Guralp CMG3 broadband seismometers were successfully installed and recovered. The first set, named OFP, was installed inside the ODP borehole 396B at 292 m below seafloor and the second one, named OFM, was installed on the sea bottom (semi-buried) close to the hole. A comparison of broadband seismic noise (1–3600 s) between OFP, OFM, and a typical continental GEOSCOPE seismic station SSB shows that the noise level of OFM is smaller (resp. larger) at periods longer than 20 s (resp. shorter than 2 s) than the one in the borehole and in SSB. The detection threshold is very low and makes it possible to get good records of teleseismic events as small as 5.4. These results were very encouraging since they demonstrate that in the future ocean bottom seismometers will provide very valuable information on earthquakes and Earth structure.
Sonoluminescence from water–ethylene glycol mixtures
Authors: Bradley Melanie , Ashokkumar Muthupandian , Grieser Franz
Published: July 2002

The emission obtained from air-saturated ethylene glycol–water mixtures has been examined using 3-ms pulses of 500-kHz ultrasound. In pure ethylene glycol at 24 °C the intensity of the signal obtained is about eight times weaker than that in pure water. At 50/50 vol.% the signals are comparable to pure water. Addition of aliphatic alcohols to a 50/50 vol.% solution quenches the signal, and the more hydrophobic the alcohol, the greater the effect. Addition of the anionic surfactant sodium dodecylsulfate enhances the signal at low concentration (1–2 mM). As the percentage of ethylene glycol in the mixture increases, the extent of the alcohol quenching and the surfactant enhancement is diminished. The effect of the additives can be explained in terms of their absorption at the solution/bubble interface and their role in controling bubble-bubble coalescence. In addition for the case of alcohol quenching, it is postulated that evaporation into the bubble also occurs and the presence of this alcohol in the core of the bubble interferes with the processes that produce sonoluminescence. This latter conclusion is similar to what we have previously raised for sonoluminescence quenching in water by alcohols [Ashokkumar et al., J. Phys. Chem. 101, 10845–10850 (1997)].
Top-down influences on phonetic processing as a function of aging
Authors: Boyczuk Jeffrey , Baum Shari
Published: July 2002

A phonetic identification experiment was conducted in order to assess the extent to which lexical information influenced low-level speech perception processes in three different age groups of subjects (20–29 years, 60–69 years, and 70–79 years). Subjects were required to label syllable-initial, bilabial stop consonants which varied in voice onset time (VOT) as either /b/ or /p/. Following Ganong [J.E.P.: H.P.P. 6, 110–125 (1980)], a pair of VOT continua with opposing lexical biases was created: one continuum ranged from the word /buk/ to the nonword /puk/ while the other continuum ranged from the nonword /bu t/ to the word /put/. VOT values for the syllable-initial /b/–/p/ phoneme were the same at corresponding steps in the two continua. Results indicated a significant influence of lexical status on phonetic identifications for all age groups. Furthermore, a significant difference in the location of the phonetic crossover boundary was observed, with older subjects showing longer VOT values than young subjects. While findings suggest that top-down processing is still a prevalent part of phonetic perception in elderly individuals, it appears that aging may bring changes in the values of the acoustic parameters used to define phonetic categories. [Work supported by McGill University.]
Three-pass mufflers with uniform perforations
Authors: Selamet A. , Easwaran V. , Falkowski A. G.
Published: July 2002

A quasi-one-dimensional approach is presented to analyze three-pass mufflers with perforated elements using numerical decoupling. The approach is further developed to include mufflers with ducts extended into the end cavities. Theoretical predictions are compared with experiments for three different muffler configurations, one fabricated and two commercially available mufflers, and shown to agree reasonably well. The effect of porosity, length of the end cavities, and expansion chamber diameter are studied. Also, the effect of ducts extending into the end cavities are investigated.
Vibration of unsymmetrically laminated thick quadrilateral plates
Authors: Liew K. M. , Karunasena W. , Kitipornchai S. , Chen C. C.
Published: July 2002

The problem of free vibration of arbitrary quadrilateral unsymmetrically laminated plates subject to arbitrary boundary conditions is considered. The Ritz procedures supplemented by the simple polynomial shape functions are employed to derive the governing eigenvalue equation. The displacements are approximated by a set of polynomials which consist of a basic boundary function that impose the various boundary constraints. A first-order shear deformable plate theory is employed to account for the effects of the transverse shear deformation. The numerical accuracy of the solution is verified by studying the convergence characteristics of the vibration frequencies and also by comparison with existing results. The new results of this study include the sensitivity of the vibration responses to variations in the lamination, boundary constraints and thickness effects, and also their interactions. These numerical values are presented for a typical graphite/epoxy material, in tabular and graphical forms.