bluuebunny/crossref_metadata_2025 huggingface dataset:
Violin quality and bridge mobility
Authors: Jansson Erik V.
Published: July 2002

In the measured bridge-mobility curves of a Stradivarius violin, two sharp prominent peaks were found at approximately 450 and 550 Hz, and a broad rounded hill with a maximum at approximately 2.5 kHz. The labeling P1 and P2 is suggested for the peaks in honor of Frederick Saunders (principal peak P) and BH, bridge hill for the 2.5-kHz hill. The P2 maximum is the highest, the BH the second highest, and the P1 the lowest. Measured bridge-mobility of soloist quality violins [E. V. Jansson, Acust. Acta Acust. 83, 337–341 (1997)] and measured radiation of Italian violins [H. Duennwald, Acustica 51, 281–287 (1982)] show similar features. The similarity indicates that the bridge-mobility predicts the sound reaching the listener’s ear well. A strong P1 and especially a strong P2 should be an indicator of a full tone. Balanced with the BH hill, it indicates the quality of a good violin. [Work supported by KTH, Swedish Natural Science Research Council, Swedish Institute, and Wenner-Gren Center Foundations for Scientific Research.]
Sleep disturbances caused by road traffic noise
Authors: Ohrstrom Evy
Published: July 2002

In the last 15–20 years, there has been an increased use of new and less expensive methods, e.g., body motility techniques (awakenings, arousal), and questionnaires (perceived sleep quality, aftereffects) in studies of noise-induced sleep disturbances, both in laboratory settings and large-scale field studies. Studies on road traffic noise indicate that LAmax levels of 45 dB may increase the time to fall asleep by 7 to 15 min. Recent studies show an acute increase in number of body movements irrespective of LAmax levels from road traffic noise and there is a significant increase of number of awakenings above 55 LAmax in the average population. Noise-sensitive groups react at 5 dB lower levels. Aftereffects of noise-disturbed sleep (reduced perceived sleep quality and increased tiredness or sleepiness during the day) have been found among the average population after acute and chronic exposure to road traffic noise at LAmax levels around 50 dB. Noise-induced sleep disturbances may also lead to lower psycho-social well-being. More research effort is needed, e.g., on effects of critial groups and situations, various types of environmental noise, effects on daily activities, effects of countermeasures against noise, and on predictive indicators of sleep disturbances for presumed health effects.
U.S. field research on nighttime sleep disturbance
Authors: Finegold Lawrence S.
Published: July 2002

This paper provides a review of field research on nighttime sleep disturbance in residential communities conducted primarily in the U.S. over the past decade. It compares the methodology for studying sleep disturbance which has evolved during this series of research projects with the research approach used historically in Europe and elsewhere. A new dose–response relationship is offered, based on a meta-analysis of a database developed from field research around civilian airports and military airbases. This paper presents the details of this database meta-analysis. The new sleep disturbance prediction curve is recommended as an update to the interim curve adopted by the U.S. Federal Interagency Committee on Noise (FICON) in 1992. At that time, there was a lack of consensus in both U.S. and European scientific communities concerning whether both laboratory and field research data should be used in the development of a new prediction curve. The new curve is based solely on field study data and a ‘‘percent awakened’’ as an objective measure of sleep disturbance. Thus, it should more accurately predict sleep disturbance in residential environments than the previous FICON curve. It is hoped that additional research will validate this new curve and further investigate habituation in newly exposed communities.
Measuring retrospective annoyance in field studies: Prerequisites, procedures, and problems
Authors: Guski Rainer , Felscher-Suhr Ute , Schuemer Rudolf
Published: July 2002

The definition and measurement of annoyance varies between studies. This paper is concerned mainly with measurement topics, e.g., graphical versus magnitude estimations or verbal scales; the effect of mentioning frames of reference with respect to (a) exposure time, (b) exposure area, or (c) range of possible degrees of annoyance/exposure. With verbal response scales, the number of response steps varies between 2 and 7; some studies simply provide for categorical judgments, others provide for nearly equidistant verbal steps—in order to allow for parametric treatments of data. In this context, an international study is reported which intended to gain comparable response scales for different languages. The decision criteria used for selecting 5 steps on the total range between the lowest and the highest possible degree of annoyance are discussed, and the use of certain verbal modifiers in English, German, and French are proposed. Together with instructions for mentioning the frames of reference, these modifiers should be able to get comparable annoyance scores in field studies.
Noise emission—A part of the risk assessment concerning the safety of machinery
Authors: Lazarus H. , Kurtz P.
Published: July 2002

ISO/IEC guide 51 describes safety aspects in products, processes, and services. EN 292/EN 414/EN 1050 describe the safety of machinery: concepts, general principles of design, and the risk assessment. For specific machinery groups standards on ISO or CEN level describe safety aspects, technical data or test methods. Problems with the implementation of noise into these standards are discussed because the reduction of emission of machinery (noise, vibration, toxic agents) has, until now, obviously been neglected, as it seems, due to the unsuitable approach of classical risk reduction. Therefore the European Machinery-Directive requires (i) a reduction of risks to the lowest possible level (ii) and the information of the user about existing residual risk. Thus machinery standards to reduce noise-emission must comprise (1) specified measuring procedures (yet existing to a large extent) including representative operating conditions for emission measurements, (2) collected emission values for each type of machinery in order to derive the state of the art, and (3) examples for noise reduction by design. Exemplary C-standards will be presented.
The description of noise emission from machinery for use in software programs for noise prediction
Authors: Probst W.
Published: July 2002

Noise prediction deals with the calculation of noise levels at workplaces from the emission values of machines. In such a calculation, the dimensions of machines, the source distribution on the machine surface, and the directivity of radiation have to be taken into account if the workplace is not far away. Unfortunately, methods of measuring emission values with enveloping surface or with the comparison method do not give all this information, which is necessary to make such a calculation. As a good approximation for many cases, the machine itself is simulated by a rigid body with many point sources on its surface. This is a similar method as is used to calculate the radiation from buildings (E DIN EN 12354-4) with some additional rules. For the future, a direct conversion from measured sound pressure or intensity levels to the source distribution data for a machine should be developed.
Influence of the deposition conditions on the elastic properties of chemical vapor deposited (CVD) diamond films studied by laser ultrasonics
Authors: Van de Rostyne Kris , Glorieux Christ , Gao Weimin , Lauriks Walter , Thoen Jan , Nesladek Milos
Published: July 2002

One of the aims in optimizing the deposition of CVD diamond is to increase the stiffness. Laser ultrasonics offers a useful tool to nondestructively investigate elastic parameters of materials. A colored liquid–transparent free-standing film configuration allowed the excitation and detection of pseudo-Lamb waves in order to simultaneously determine the longitudinal (vL) and transverse (vT) acoustic velocity of the film. The absorption of pulsed laser light by the colored liquid served as an efficient conversion mechanism of optical energy into elastic energy. The excited waves were detected with a wide bandwidth photodeflection setup. Several free-standing films, deposited under different conditions, were investigated.
Numerical simulation of ultrasonic shock wave propagation in lossy liquids obeying a frequency power law
Authors: Steiger Eckard , Ginter Siegfried
Published: July 2002

Ultrasonic shock waves are applied for several noninvasive therapies like extracorporal lithotripsy. In order to design and to optimize therapeutical devices it is essential to predict accurately the shockwave propagation through the arrangement transducer/coupling medium/human tissue. An explicit high-order FDTD-discretization of a set of nonlinear acoustic equations has been shown to model the lithotripter pulse propagation in water in a quality that beats all other known methods. To consider attenuation caused by tissue structures, realistic broadband models of soft tissue attenuation are provided by frequency power laws that include strong dispersion. In this contribution a new method to include these frequency power laws into the explicit FDTD model is presented. It is based on a causal continuous time domain formulation of the attenuation law which contains a Riemann–Liouville derivative operator of fractional order. This operator is discretized by using a quadrature formula. The resulting FDTD algorithm is verified. It turns out to be an efficient tool to compute the dispersive and attenuating effects of soft tissue on the propagation of high-intensity ultrasonic pulses and shock waves. Exemplary nonlinear dispersive propagation of a lithotripter pulse through tissue is simulated.
Nonlinear waves in closed tubes
Authors: Bednařík Michal
Published: July 2002

The purpose of this investigation was to choose a suitable model equation for description of finite amplitude waves in closed tubes filled with air. The boundary layer effects were also taken into account. Unfortunately, a general analytic solution of the used model equations has not been known, consequently it was necessary to find a numerical method for solution of these equations. When a standing wave is driven to high amplitude in an acoustic resonator, nonlinear effects couple energy from low- to high-frequency modes, ultimately resulting in shock wave formation and heightened dissipation. Therefore this work was focused on study of suppressing the energy transfer into harmonics that represents a parasitic loss. This suppressing of the energy transfer enables store energy in the form of an acoustic standing wave in a resonant cavity more effectively.
Modeling masking patterns for sinusoidal and narrow-band noise maskers
Authors: Derleth Ralph P. , Dau Torsten , Kollmeier Birger
Published: July 2002

In a recent paper by Moore, Alcántara, and Dau [J. Acoust. Soc. Am. 104, 1023–1038 (1998)] masking patterns for sinusoidal and narrow-band noise were presented. Data were collected for all four masker-signal combinations. The same subjects participated in the different experimental conditions and the same experimental procedure was used in each case. Despite the influence of combination products, a strong influence of temporal fluctuations on the masking patterns for sinusoidal maskers was found for masker-signal frequency separations up to a few hundred Hz. The present study shows model predictions obtained with the modulation-filterbank model [Dau et al., J. Acoust. Soc. Am. 102, 2892–2905 (1997)]. This model is able to use envelope fluctuations, for example, beats, as a detection cue, but it does not contain a nonlinear peripheral filter stage. Thus the model predictions offer the possibility to separate between effects caused by temporal effects like beating and those caused by combination products. As in the experimental data of Moore et al., less masking was found for the tone-on-tone masking condition than for the tone-in-noise masking condition, for tone-masker frequency separations lower than 250 Hz. The asymmetry of masking between the signal-tone masker-noise condition and the signal-noise masker-tone condition can also be accounted for quantitatively by the model.
Frequency selectivity in amplitude-modulation processing
Authors: Ewert Stephan , Dau Torsten
Published: July 2002

Effects of frequency selectivity in the audiofrequency domain are well established and associated with the existence of independent frequency channels (critical bands). Several studies suggested a comparable spectral decomposition in the modulation-frequency domain. However, in these studies the bandwidth and the shape of the postulated channels were derived only indirectly and for a restricted range of low-frequency modulations. A principal problem in modulation masking experiments is the restricted dynamic range of the modulation depth available to detect the test modulation. Particularly, in conditions with a stochastic carrier and a stochastic masker-modulation, two basic factors limit resolution: The amplitude statistics of the bandlimited masker-modulation noise and the intrinsic envelope fluctuations of the carrier noise. The present study offers an optimized experimental condition for the derivation of modulation-filter shapes. A direct approach to obtain the modulation-filter shape is presented and modulation-tuning curves are derived up to modulation rates of 100–160 Hz for different spectral positions of the carrier. In addition, across-frequency effects in modulation masking with the probe and the masker separated by about two octaves are examined. The experimental results are compared with threshold estimates based on the integrated modulation power in a hypothetical modulation filter.
Parameter estimation of the passive cochlear model
Authors: Dimitriadis Emilios K. , Chadwick Richard S.
Published: July 2002

Two critical issues in every cochlear modeling effort are the choice of model dimensionality and the corresponding model parameters of the passive system. The cochlea is often represented by an axial array of single or multiple degree-of-freedom lumped parameter systems, which are axially coupled via the fluid–structure interaction. For most cases, precise anatomical data for the axial distribution of model parameters are lacking and one has to make educated guesses as to their values. The problem is more complicated with multiple degree-of-freedom models, where it is not clear which parts of the structure should be lumped together to constitute the different degrees of freedom. In this work, one-, two-, and three-degree-of-freedom systems are compared and contrasted in their ability to predict passive, in situ measured responses. Following that, an effort is made to apply parameter estimation techniques that will result in models which optimally predict passive in situ data. The estimation methods are based on least-squares fitting of recorded frequency response data, but the relatively large number of parameters requires that a number of auxiliary conditions be established based on our partial knowledge of anatomy and physiology. Issues are discussed and recent results presented and contrasted among the different models.
Comparisons between but not within sounds are impaired in stroke victims with unilateral neglect
Authors: Cusack Rhodri , Carlyon Robert P. , Robertson Ian H.
Published: July 2002

Neglect is characterized by impaired performance on visual tasks in which competing stimuli are presented and patients show little or no awareness of stimuli further towards the left. Described here is a previously unreported deficit in making comparisons between sequentially presented sounds. In experiment 1, ability to lateralize a narrow-band noise with an ITD was compared to performance on a 3IFC ITD discrimination task using similar sounds. Patients performed similarly to age-matched controls on the one-interval task, but were highly impaired on the three-interval task. This might be due to a temporal attention disorder, or to a problem tracking sounds at different spatial locations. In experiment 2, performance was tested on a nonspatial, 2IFC frequency discrimination task. Patients were again severely impaired relative to age-matched controls. This could not be explained by differences in peripheral frequency discrimination (measured using a one-interval FM detection task). These findings are unlikely to be a general effect of task difficulty, as (1) a control group with frontal lesions performed very similarly to the age-matched normals and (2) 3IFC tasks are usually considered to be easier than yes–no tasks. They indicate a specific impairment in attending to sequential sounds.
Computational audition: Auditory perceptual organization and systematic music theory
Authors: Seifert Uwe , Schmidt Lueder , Randolph Eichert
Published: July 2002

The term ‘‘computational audition’’ encompasses top-down and bottom-up approaches in hearing, speech, and music. As an information processing approach, the main task is to relate auditory funtion (i.e.,perceptual processes and representational structures) to structure (i.e., neural circuits). It is argued that there are two main (Gestalt) problems in computational audition: (a) the well-known constancy problems in auditory perception as exemplified in Bekesy (1969, 1974) and (b) the correspondence problem in sequential integration which is the main grouping problem in temporal pattern perception. These problems are best attacked from functional psychophysics and a neuroethological point of view in terms of intercausal nets [Wirkungsgefuege; Mittelstaedt (1969); Bischof (1995)]: Connected functional input–output relations are interpreted as causal relations. Therefore, a research strategy for auditory image formation [Yost (1992)] which may allow connecting signal and information processing approaches is proposed. This functional psychophysical approach to computational audition in connection with neuroethology in research on music perception is called systematic music theory. Computational audition may offer the possibility for a ‘‘theory of music’’ in the sense of Hermann von Helmholtz and Carl Stumpf which is related to a biologically rooted theory of hearing.
On the tones that make music
Authors: Houtsma Adrianus J. M.
Published: July 2002

Advances in musical acoustics, music psychology, architectural acoustics, and electroacoustics during the past few decades have all contributed to our present understanding of the complex processes involved in making, listening to, and enjoying music. Psychoacoustics has made contributions by exploring basic relationships between tones, tone combinations, and tone sequences on the one hand, and sensations of loudness, pitch, timbre, consonance, dissonance, and rhythm on the other. Statistical analyses of musical intervals used in certain compositions, for instance, show a clear relationship with auditory critical bandwidth. Musical instruments typically used for playing lead voices or complex harmonies are found to have lower partials with an exact or nearly exact harmonic relationship so that they can convey clear and unambiguous pitch sensations. Even spatial effects have been used by composers since the Renaissance to the present day. Such effects don’t always lead to the intended results, however, because of the often unpredictable acoustic behavior of listening spaces. Reinier Plomp has made significant contributions to our present understanding of these problems. The title of this presentation is, in fact, the subtitle of an auditory demonstration CD recently issued by him in The Netherlands.
Active control of enclosed sound fields via impedance changes
Authors: Galland Marie-Annick , Lacour Olivier , Thenail Denis
Published: July 2002

The potentialities of active strategies based on boundary condition control are investigated for globally reducing the noise in cavities. Two active systems previously developed [Furstoss, Thenail, and Galland, J. Sound Vib. 203, 219–236 (1997)] are exploited in order to assign the most suited wall impedance for noise reduction: the first is referred to as ‘‘direct’’ control and permits precise realizations for harmonic excitations, the second is a hybrid passive/active feedback control well suited for random noise treatments. Experimental analysis and numerical developments are conducted on a rectangular three-dimensional cavity closed by a simply supported elastic plate. Noise is generated by an external load applied to the plate. Different impedance values are successively assigned, and their effect is estimated on the global sound-level reduction. Attention is also given to plate vibration changes, which may occur. Different typical behaviors of the plate-cavity system are first investigated for harmonic excitations. The hybrid control system appears to be a good compromise for all cases, and shows promising behavior when dealing with broadband excitations.
Measuring perceptual equality
Authors: Portele Thomas
Published: July 2002

When performing F0 stylizations and parametrizations in order to establish the essential parts of an F0 contour, it is necessary to assess the similarity between original and stylized contours. The most reliable method is a perceptual assessment, which means in its most severe form that no differences are perceptible between original and resynthesized versions. Such tests have a number of possible influences (resynthesis quality, auditory storage, whether or not perceptible diffences are included), and they are tedious and time-consuming, as will be exemplified by results obtained in the evaluation of this maximum-based description. Computational comparisons, on the other hand, are unable to mirror human perception, because it is well known that small differences in the acoustic domain may be perceived while larger differences may pass unnoticed. The mean difference, as measured by some researchers, is problematic, because the goal of stylization is to abstract away from unimportant features. A successful stylization is perceptually equal to the original but has a large mean difference caused by successful abstraction. The current limited knowledge of pitch perception and interpretation requires perceptual tests to evaluate stylization quality.
Comparing materials for the evaluation of symptom severity in the read speech of spasmodic dysphonia patients
Authors: Kumada Masanobu , Bell-Berti Fredericka , Honorof Douglas N.
Published: July 2002

Reliability and validity of evaluation methods for assessing the degree of severity of spasmodic dysphonia (SD) symptoms have become a matter of concern for voice specialists. With the syllable method [M. Kumada et al. (1997)], overall degree of severity is represented by the proportion of impaired syllables. This method has shown promise for English, though it appears to work better for evaluating prose read aloud than for evaluating the recitation of sequences of cardinal numbers, because inappropriate pauses are more easily identified in prose. The present study aims to compare types of English prose according to their tendencies to reveal SD symptoms. Specifically, audio recordings of seven patients reading Fairbanks Rainbow Passage are evaluated by five voice professionals, as are audio recordings by the same patients of sentences in which tempo is expected to be highly predictable and thus, by hypothesis, potentially more stable for purposes of cross-speaker comparison. These sentences are constructed entirely of stressed monosyllables. If the phonatory dysfunction observed correlates with disturbances to so-called stress-timing patterns [K. L. Pike, Intonation of American English (Ann Arbor, 1945)], sequences of stressed monosyllables would be expected to be especially useful in the evaluation of SD.
Effect of target source and dynamics on voice F0 stability in the presence of auditory feedback pitch perturbations
Authors: Burnett Theresa , Larson Charles
Published: July 2002

The quickness with which a motor system recovers from an unanticipated perturbation is an indication of its stability. This principle was examined with regard to the voice F0 control system and auditory feedback. Trained singers sang a steady note or an upward glissando, either from memory or by tracking a synthesized tone. At an unanticipated time during phonation, the singers’ auditory feedback pitch was ‘‘flattened’’ by 1 semitone for a period of 100 ms, creating an effect similar to that which would be heard during a production error. All singers produced voice F0 changes in response to the auditory perturbations, and many of these voice F0 changes were oscillatory in nature. The number of oscillations and the speed with which they were dampened were measured and compared across the different types of vocal productions (steady note versus glissando) and across the different target sources (pitch memory versus synthesized tone). Results indicate that voice pitch stability varies with the nature of the target.
Rapid changes in speech parameters with a change in auditory stimulation from a cochlear implant
Authors: Perkell Joseph , Jackson Lekisha , Zandipour Majid , Vick Jennell , Lane Harlan , Matthies Melanie
Published: July 2002

To investigate the speed of speech production changes in response to a change in hearing, the speech processors of two cochlear implant users were switched on and off a number of times in a single experimental session for each subject. The subjects repeated short utterances (‘‘a said,’’ ‘‘a shed,’’ ‘‘a sad,’’ and ‘‘a shad’’) many times in semi-random order. The transitions between hearing (on) and nonhearing (off) states were timed to occur between utterances, and the number of utterances between transitions was varied to minimize subject anticipation of the change. Using transition times as line-up points, values of median and skewness of sibilant spectra and vowel F1, F2, duration, and SPL were each averaged over repetitions of each utterance and compared across the on–off and off–on transitions. Vowel SPL and duration had changed by the first utterance following the transition, indicating that the subjects were using subtle aspects of the processor output to detect its state even in the absence of overt sound input. Changes in spectral median and skewness and F1 and F2 were less immediate, more varied, and differed between the two subjects. The paradigm is currently being refined to further investigate this issue. [Work supported by NIH.]
Exploitation and usage of signal evaluating concepts of nature—Ultrasonic data acquisition and neural network signal processing
Authors: Fritsch Thomas , Wrobel Miroslaw , Glaser Eckard , Grassmann Janet
Published: July 2002

The objective of the work is the mapping of the main features of data acquisition and neural signal processing concepts, which can be found in nature like the biosonar of bats and dolphins, to technical applications like medical ultrasound or material testing. A first attempt in this direction was the exploitation of higher harmonics of an emitted ultrasound wave for the measurement of very weak signals by an acousto-optical Mach-Zehnder- and Sagnac-Interferometer. A second ongoing work is the analysis of a frequency-modulated signal by neural network signal processing methods for the purpose of medical ultrasound application. The first promising results give rise to the hope of further technical applications. a)Former address. Currently with BRAIN.
Multidimensional adaptive beamforming for integrated active-passive sonar and medical imaging applications
Authors: Stergiopoulos Stergios
Published: July 2002

The present investigation introduces an adaptive beamforming scheme that separates the computationally intensive multidimensional beamforming into two simple modules, which are line and circular array beamformers. This approach minimizes the number of degrees of freedom associated with the adaptation process and provides near instantaneous convergence, which is essential for integrated active-passive sonar and medical ultrasound imaging applications. The proposed adaptive processing concept has been implemented in an integrated active-passive real-time sonar deploying a cylindrical array. Preliminary efforts include also the application of a line array adaptive beamformer in medical ultrasound imaging systems. Real data results from the adaptive and conventional beamforming outputs of the cylindrical array sonar system and the line array of the ultrasound system demonstrate the superior performance of the adaptive beamformer in suppressing the reverberation and cluttering effects in active sonar and medical ultrasound applications. Moreover, for passive sonar applications, the adaptive processing provides substantially improved angular resolution performance as compared with that of the conventional beamformer. Both these two performance improvements for a line and a cylindrical array sonar are of particular importance for mine hunting operations.
Multidimensional array signal processing with multidimensional matrix operations
Authors: Rogozovskyi Oleg A.
Published: July 2002

Digital processing of multidimensional (m-D) array signals requires an adequate description. Such descriptions could be made by using multidimensional matrices. Associating m-D matrices with multilineal forms, one could derive a set of algebraic operations. Most important of them for the signal processing is the m-D convoluted multiplication. It is shown that, making use of the m-D matrix operations, one can save a computational load. It could be three times less for multiplication by processing of the 3-D data matrix. A spatio-temporal processing with a time processing on the first stage (e.g., by Fourier transform) brings some advantages. If the signals are wide band, short time, or nonstationary (e.g., from array with position distortions or from moving one), such processing on the first stage could be noneffective. Constraints on signal and array parameters for this case are derived. If this constraint is not fulfilled, first stage time processing must be replaced by a spatial one. For sonar, radar, and image applications that could be beamformers and focusing algorithms. For both variants of the spatio-temporal processing, log-likelihood algorithms for 1-D, 2-D, and 3-D arrays are derived. Postprocessing algorithms with high resolution and parameter tracing by m-D matrix description are obtained also.
A new, semiempirical model for predicting bistatic surface backscattering strengths
Authors: Gauss Roger , Fialkowski Joseph
Published: July 2002

A Lloyd-mirror model of bubble-cloud scattering, along with perturbation theory for the rough air–sea interface, have been used as a basis for generating a new algorithm for predicting the strength of acoustic backscatter from the ocean surface. Multiparameter curve fits of the model to acoustic data from the Critical Sea Test program (1988–1996) and other at-sea experiments have been used to derive a new, semiempirical description of the dependence of surface backscattering strength on the incident and scattered grazing angles, the acoustic frequency, and environmental descriptors. The model represents an advance on previous algorithms (Chapman–Harris, Ogden–Nicholas–Erskine) in several ways: (1) a much improved, physics-based description of the grazing-angle dependence, applicable to arbitrarily low grazing angles; (2) a much improved description of low-to-moderate sea-state bubble scattering; (3) can handle vertically bistatic geometries; and (4) is applicable to a broader range of frequencies (50 to 5000 Hz). [Work supported by ONR.]
Sound irradiation from walls when excited by impact sound from fresh and waste water lines
Authors: Schroeter Knut , Teuber Wolfgang
Published: July 2002

The noise produced by fresh and waste water lines is usually transmitted into neighboring walls and into rooms which should be protected. Impact sound leads to sound velocity levels which can be measured on the wall. With the help of irradiation coefficients, airborne noise levels can be calculated taking the light and heavy walls of two IAB test rooms into consideration. To vary the transmission of structure-borne sound, different pipe clamps with insulated thimbles were used. The measurement will be compared with earlier results in these test facilities. Comparisons with in situ measurements will also be made
Speech intelligibility in simulated classroom sound fields
Authors: Bradley John
Published: July 2002

Speech intelligibility in classrooms is determined by both speech/noise ratios and room acoustics factors. Using a rhyme test, speech intelligibility scores were obtained in sound fields simulated using an electroacoustic system in an anechoic room. The 16 sound fields consisted of the combinations of four levels of speech/noise ratio and four levels of a room acoustics measure giving an even distribution over all conditions likely to occur in realistic situations. The results were used to test the validity of acoustical measures that reflect the combined influence of speech/noise and room acoustics factors such as the speech transmission index, the Alcons measure, and useful/detrimental sound ratios. They were also used to investigate improved acoustical measures for speech in rooms and to evaluate the importance of speech/noise ratios relative to room acoustics factors.
System development to reduce floor impact sound in apartment houses
Authors: Jang Jaehee , Lim Byunghun , Lee Sangwoo
Published: July 2002

The floating floors used to reduce floor impact sound in European countries are not as compatible with Korean style floors because every residential floor in Korea is heated up by the floor heating method. In this case, considering the floor heat radiation effect, the cement screen is constructed to be about 40 to 50 mm thick. So constructing the low-density damping materials, such as glasswool, under the cement screen over 20 mm definitely makes some cracks. To prevent this kind of floor crack and to improve the impact insulation performance, the floating floor system using a plastic pallet and rubber was developed. The developed plastic pallet is 30 cm wide ×60 cm deep ×4 cm high and is designed to array on a concrete slab; above this plastic pallet, a 2-cm thick thermal insulator is constructed. On this, the insulator heating coil is installed, and finally the 4-cm-thick cement screen is constructed over that. The test results of impact insulation performance for the developed system show good improvement, about 15 dBa between before and after installation of the system.
The Larynx–Melon–Vestibular Lips (LMVL) model of the dolphin sonar. II. The melon beam former
Authors: Fitzgerald James W.
Published: July 2002

The LMVL model of the dolphin sonar is based on the following system components: (1) the Larynx, controlled by the palatopharyngeal sphincter and operating as a ‘‘sawtooth’’ relaxation oscillator, is the source of the echolocation pulses (the so-called ‘‘clicks’’), and its acoustic output is coupled to the melon through the impedance matching nasal ducts; (2) the Melon, because of its low sound velocity, acts as a ‘‘slow waveguide’’ to form the observed forward-looking beam patterns; and (3) the residual air in the nasopharyngeal cavity acts as an air-pressure reservoir to energize relaxation oscillations of the Vestibular Lips, resulting in the lip-modulated tonal phonations (the so-called ‘‘whistles’’) that radiate through the corresponding vestibular sac. The larynx sawtooth generator has been treated previously [J. W. Fitzgerald, Part I Oceans ’94, Vol. I, pp. 271–276 (Sept. 1994)]. The measured sound velocity in the melon decreases with temperature from v≂1.39×105 cm/s @10°C to v≂1.28×105 cm/s @40°C. Melonlike acoustic slow waveguides, with intermediate sound velocities, yielded average pulse beamwidths of θ1≂11.5° (−3 dB) and θ2≂20.0° (−10 dB). This compares to accepted average values from measurements on live dolphins of θ1≂10.0° (−3 dB) and θ2≂21.8° (−10 dB) [W. Au, The Sonar of Dolphins (Springer-Verlag, New York, 1993), p. 105]. These preliminary measurements of melonlike acoustic slow waveguides, and the dissertation of Part I of this series, support the LMVL model of the dolphin sonar.
Seabottom roughness study using a hydrosweep–multibeam system
Authors: Chakraborty Bishwajit , Kodagali Vijay N. , Schenke Hans W.
Published: July 2002

Seabottom profiling using a multibeam echosounder is a well-known method to acquire a high-resolution and high-density data set for bathymetric mapping of survey area. The use of multibeam echosounder backscatter signals for bottom roughness characterization is a modern technique. Here, the model results of seabottom backscatter data using a hydrosweep-multibeam system, from some of the geologically well-known areas of Southern Oceans, are presented. Using the capabilities of multibeam systems, angular backscatter strengths are determined employing various corrections. Different bottom backscattering modeling techniques like the composite roughness [Jackson et al., J. Acoust. Soc. Am. 79, 1410–1422 (1986)] and two-layer Helmholtz–Kirchhoff model [Talukdar et al., J. Acoust. Soc. Am. 97, 1545–1558 (1995)] for estimation of bottom roughness is applied. Various seabottom parameters like root-mean-square (rms) relief height, correlation lengths, attenuation coefficients, and layer thickness using the two-layer Helmholtz–Kirchhoff model are calculated. The interface roughness parameters, i.e., slope and intercept values, and volume roughness parameters are computed using the composite roughness theory for the same geological areas.
Generalized additive models for classifying sea-bottom types
Authors: Schneider Patrick , Hedgepeth John
Published: July 2002

One encounters many types of sea-bottom, a continuous spectrum of all kinds of transitions between one category and another, not just clear-cut categories. A number of parameters, which the BioSonics Visual Bottom Typer extracts from the data, are looked at as a continuum, from one bottom type to another. As generalized additive models (GAMs) are nonlinear regression models, they can be useful to find relating functions for some of the parameters, significant for different bottom characteristics. The advantage of the GAMs is that if there should be a linear relation between two parameters, they are also able to reveal this, because a linear model is included as one special case in a GAM. Also, there can be problems with GAMs: There may not be a single transition from, e.g., soft/muddy to hard/rocky, but different kinds of bottom types can be connected in arbitrary ways; building a library from known bottoms, as has previously been done, might be the easiest and most practicable way.
Renal vasoconstriction caused by SWL to one pole of one kidney may attenuate the injury caused by subsequent SWL to the other pole of that kidney
Authors: Willis Lynn R. , Evan Andrew P. , Connors Bret A. , Blomgren Philip , Lingeman James E.
Published: July 2002

These experiments examined the size of the renal lesions produced by SWL after 2000 shocks applied first to one pole and then immediately to the other pole of the same kidney. Anesthetized, 6-week-old pigs received 2000 shock waves at 24 kV (Dornier HM3) first to the lower pole and then to the upper pole of the same kidney (4000 shocks in all). Bilateral measurements of renal blood flow (RBF) were obtained 1 h before and 1 and 4 h after SWL. Lesion sizes in each pole were determined by serial sectioning and digital photography. SWL successively to lower and then upper poles in each of two pigs caused marked bilateral renal vasoconstriction (reduction of RBF). In one pig, the upper-pole lesion was only about 5% the size of the initial lower-pole lesion. In the second pig, the lesions in the upper and lower poles were of similar sizes. In both pigs, the combined lesion sizes after 4000 shocks (6.81% and 5.72%, respectively) were nearly the same as the size of lesions produced by a single application of 2000 shocks to only one pole (6.1±1.7). The data suggest that renal vasoconstriction limits the renal injury caused by SWL.
A simple three-dimensional (3-D) sound intensity probe
Authors: Druyvesteyn Erik , de Bree Hans-Elias , Roozen Bert
Published: July 2002

An important property of sound intensity measurements is that the free-field properties of a sound source can be determined, although the source is positioned in a reverberant environment. The standard intensity probe consists of two closely spaced, accurately matched pressure microphones (p-p probe). A 3-D intensity probe consists of three pairs of matched microphones. The necessity of accurate matching makes such a probe large, complicated, and expensive. As an alternative for the p-p probe a p-u probe has been published [104th AES Convention Amsterdam; preprint 4651], where the particle velocity (u) is determined using the Microflown. It consists of two heated wires, 40 mm apart. The temperature difference of both wires is linearly dependent with the particle velocity (u) and can be measured accurately. A 3-D intensity probe will be reported consisting of one (pressure) microphone and three particle velocity sensors placed orthogonal for the velocity vector (u) determination. Experiments have been performed in an anechoic and a reverberation room. It was found that the free-field properties of a sound source, as determined from experimental results in the reverberation room, coincide with the experimental results in the anechoic room, showing that this 3-D intensity probe works satisfactorily.
What makes singing expressive?
Authors: Sundberg Johan
Published: July 2002

Answers to this question are sought in two experiments analyzing performances of songs from the classical Lieder repertoire as sung by professional baritone singers. In one experiment, two versions of the same excerpts were compared; in one the singer attempted first to sing with as little expression as possible, and then as in a concert. In another experiment, a professional singer performed a Lied with a prerecorded piano accompaniment provided over earphones (a) with the original text of the poem and (b) replacing the text syllables with the syllable [mV:]. The significance to expressiveness of observed differences is evaluated by synthesis experiments. The results suggest that expressivity contains information on musical structure, facilitates categorization of tones, and adds an emotional coloring. Expressivity is communicated by means of a code involving meaningful modulation of various parameters such as tempo, pitch, loudness, and vibrato extent. It also includes certain characteristic patterns such as ascending glides to target pitches, and smoothing or sharpening of loudness and pitch contours.
Acoustical specification and musical meaning
Authors: Clarke Eric F.
Published: July 2002

Musical meaning has commonly been regarded as only very distantly related to music’s acoustical surface. This paper proposes that there is actually a rather close relationship between the two—that musical meaning is specified with considerable immediacy in sound. An important aspect of the meaning of an everyday sound in the environment is its source, and this same principle can be interestingly extended to music if the notion of ‘‘source’’ is generalized somewhat to encompass more than just physical/instrumental origin. Following a brief introduction to the theory of ecological acoustics on which such a claim is based, and an illustration of its application to everyday environmental sounds, a number of musical examples will be used to illustrate the diverse aspects of musical meaning that are specified in musical sound, ranging from states of the performing body to the cultural allegiances of musical genres.
The response of the acoustic reflex to noise from low-flying military aircraft
Authors: Kerry Geoff , Lomax Claire , Wheeler Peter D. , James David J.
Published: July 2002

Noise from low-flying military jet aircraft is often characterized as loud and sudden. Some researchers have suggested that the rise time of noise from such operations might be faster than the response time of the acoustic reflex, reducing protection to the inner ear. Recordings of Tornado GR1 overflights have been applied to simple models of the middle ear taken from the literature to estimate the likely response of the acoustic reflex and the attenuation of noise transmitted to the inner ear. Results indicate the reflex will provide some degree of protection to this type of noise, and that the rate of rise of the stimulus influences both the speed of the reflex response and the attenuation at a specific time. This procedure is complicated and relies on certain assumptions being made. Another approach is considered which uses complex computer models of the human ear, which allow simulation of a range of conditions together with the possibility of defining the cochlear response. Both approaches are presented, and the direction of future work toward defining a descriptor for the assessment of possible noise-induced auditory effects is discussed.
Combined application of computer simulation and sound quality in the design of a home appliance
Authors: Tinianow Brandon D. , Cimerman Benjamin
Published: July 2002

Computer-generated simulation tools are commonly used for acoustical product design, but often for spectral levels only. Sound quality, as expressed in sones and phons, quantifies sound as perceived psychologically by a listener, but possesses no predictive capability. In this study, both methods were combined to improve an appliance’s performance in terms of noise. Using intensity mapping, noise paths contributing most to user annoyance were identified. A computer model of the appliance was then created using the widely recognized statistical energy analysis method. This model was employed to simulate design modifications targeting the paths identified as most critical by the sound quality study. Design modifications were implemented in a hardware prototype of the appliance as suggested by the model and this re-designed appliance was again subjected to the sound quality assessment. Results show that the appliance’s performance was significantly improved.
A system for natural reproduction of sound and vibration
Authors: Remmers Hermann , Reckhardt Carsten , Bellmann Michael
Published: July 2002

For the psychoacoustical evaluation of sound, usually artificial head recordings are reproduced with headphones or loudspeakers. Interior aircraft or car noise, however, contains high sound and vibration energy components below 20 Hz. If these spectral components are not reproduced, subjects often complain about an unnatural hearing impression. In this paper, a reproduction system is presented that extends the audio bandwidth down to 2 Hz. For presenting vibration signals, the subject’s chair (e.g., aircraft or car seat) is mounted on an exciter system. The three-dimensional vibration signal spans the frequency range from 6 to 80 Hz. A report is given on psychoacoustic experiments and results with this sound and vibration reproduction system.
Sound quality design for high-speed trains’ indoor noise: Psychoacoustic evaluation of tonal components
Authors: Huth Christine , Fastl Hugo , Widmann Ulrich , Hölzl Georg
Published: July 2002

For the specification of the sound quality inside future high-speed trains, tonal components produced by the motors or corrugated rails can play an important role. Therefore, in psychoacoustic experiments, the dominance of tonal components at 630 or 1250 Hz was assessed. For an increase of the corresponding 1/3-oct band by 20 dB, a clear tonal character is audible which is only half as pronounced for an increase of 12.5 dB at 630 Hz or 10 dB at 1250 Hz. In line with the expectation, no tonal quality is perceived, if the 1/3-oct band in question is not enhanced. However, a decrease of sound energy in a 1/3-oct band by 20 dB can also produce a faint tonal sensation with a magnitude of about 1/10 of the tonal sensation produced by an increase of 20 dB. The results obtained with stimuli simulating the sound quality inside high-speed trains are in good agreement with data from basic psychoacoustic experiments. Therefore, it is expected that sound quality evaluation of high-speed trains indoor noise can profit from a multitude of psychoacoustic data available.