bluuebunny/crossref_metadata_2025_split huggingface dataset:
Loudness and the acoustic reflex
Authors: Margolis Robert H. , Popelka Gerald R. 
Published: October 2005

The hypothesis that loudness is constant at acoustic-reflex threshold is examined. Acoustic-reflex thresholds were measured in five normal-hearing adult subjects for octave frequencies from 250 to 4000 Hz, for a narrow-band noise (BW=50 Hz) centered at 500 Hz, and for a wide-band noise. After acoustic-reflex threshold was determined, the loudness of the reflex-threshold stimulus was measured utilizing a monaural loudness-balance procedure employing a 1000-Hz comparison tone and a Method of Constant Stimuli. Results indicate that for the activating stimuli used in this experiment, loudness at acoustic-reflex threshold varies over a 17-dB range. The range would probably increase if lower frequency activating stimuli were used. The data suggest that the acoustic reflex is not dependent on some critical loudness of the activating stimulus.
Subject Classification: 65.50, 65.22, 65.75.
Comments on summarization of the findings of Liberman e
t a
l. regarding the role of formant transitions in the perception of voiceless stops
Authors: Winitz H. , LaRiviere C. , Herriman E. 
Published: October 2005

In a recent paper [LaRiviere et al., J. Acoust Soc. Am. 57, 470–475 (1975)], the term ’’vocalic transition’’ was introduced with reference to an hypothesis generated by the authors. In this letter, a distinction is drawn between vocalic transition and formant transition with respect to literature citations.
Subject Classification: 70.30, 70.70.
Acoustic wave propagation in a viscoelastic fluid undergoing a simple steady shearing motion
Authors: Schwarz W. H. 
Published: October 2005

The theory for the prediction of the absorption and dispersion of forced acoustic waves propagating through a viscoelastic fluid in a steady simple shearing motion is presented. The stress tensor is represented by an approximate constitutive equation for a simple fluid obtained by a functional expansion about the basic state of a motion with a constant-stretching history. The linear terms are written as integrals, having kernels identified as shear and compressional relaxation functions. The absorption and dispersion depends on the direction of acoustic propagation relative to the shearing axis. Two cases are examined and the appropriate relaxation functions, or alternatively, the complex viscosity functions, obtained. These forms are compared to the shear relaxation functions obtained from shear oscillation experiments. The special case of acoustic wave propagation through a viscoelastic fluid, otherwise at rest, is considered and the results are compared to existing theories and experimental data.
Subject Classification: 35.50, 35.24.
Optimal primary spectra for parametric transmitting arrays
Authors: Clynch James R. 
Published: October 2005

The use of more than two spectral components in the primary signal of a parametric endfire array is considered. Equations are developed for the spectra of N components which maximize the farfield SPL for shock-free primaries in dispersionless media. Effects of the variation of attenuation with frequency are shown to have a considerable influence on the shape of the optimal spectra. For the case of attenuation proportional to the square of the frequency, the optimal spectra are functions only of the downshift ratio R and the number of components N, and not functions of the absolute value of the frequencies. The optimal spectra and waveforms for several sets of R and N values are shown. It is found that a 3-dB increase over a two-component primary can be obtained with three or four components for a wide range of downshift ratios. At extremely high primary powers, an increased tendency toward shock formation may negate this gain. Beamwidths were found to be essentially unaffected.
Subject Classification: 25.35; 60.10.
Parametric acoustic receiving array. I. Theory
Authors: Truchard James J. 
Published: October 2005

Closed-form solutions are derived for several configurations of the parametric receiving array. First, the solution for the interaction of a high-frequency spherical wave from a point source and a low-frequency plane wave is obtained theoretically by using a two-dimensional stationary phase solution of Westervelt’s scattering integral. The result is in turn used to generate the solution for parametric receiving arrays with various pump transducers, including a truncated line source, a rectangular piston, and a circular piston. In each case, the observer is assumed to be in the farfield of the pump transducer, but the result includes the effects of interaction in the nearfield of the pump transducer. The solution of the parametric receiving array with a point source pump and a truncated line receiver is also found. The theoretical solutions include the effects of misalignment of either the pump or receiving transducer.
Subject Classification; 25.35; 30.85.
Parametric acoustic receiving array. II. Experiment
Authors: Truchard James J. 
Published: October 2005

A series of experiments was conducted with a 48-ft parametric receiving array at a pump frequency of 90 kHz. An omnidirectional transducer was used with either a rectangular or a square piston transducer. Each of the three transducers could be used as either pump or receiver, so that a variety of parametric receiving array configurations could be realized. The piston transducer could be independently rotated, to examine the effects of misalignment. Theoretical and experimental results are compared for the parametric receiving array with several transducer arrangements. With either the pump transducer or the receiver misaligned, the difference frequency beam pattern is asymmetrical and is the mirror image of the sum frequency beam pattern. The agreement between theory and experiment was excellent.
Subject Classification: 25.35; 30.85.
Calculation of the effect of internal waves on oceanic sound transmission
Authors: Flatté Stanley M. , Tappert Frederick D. 
Published: October 2005

The signal received by a hydrophone in the ocean many kilometers from a steady sound source fluctuates dramatically due to variations of the speed of sound in sea water. By inserting an empirical model of internal-wave-generated sound-speed variations into an acoustic-transmission computer code, we have shown that internal waves cause significant variations in sound transmission at 100 Hz, comparable in size and frequency to the variations observed in field experiments. We have also studied the usefulness of vertical hydrophone arrays.
Subject Classification: 30.25, 30.82; 28.60.
Cavitation dynamics: II. Free pulsations and models for cavitation bubbles
Authors: Flynn H. G. 
Published: October 2005

A mathematical formalism developed for investigating the dynamics of cavitation bubbles has been used to obtain numerical solutions describing the behavior of bubbles of different initial radii that are damped by heat conduction, viscosity, and compressibility. Calculations have been made to determine two measures of damping, the maximum temperatures, the maximum pressures, and the resonance frequencies of bubbles set into pulsations by a pressure pulse. In general, these quantities are controlled by heat conduction and viscosity at small amplitudes and mainly by compressibility at large amplitudes of motion. One measure of damping—the energy dissipation modulus—has a peak at a well-defined maximum radius. This peak serves to define a transition radius; for pulsations with amplitudes greater than this transition radius, the fraction of available energy dissipated in a cycle decreases and hence very large internal energy densities may occur. A second transition occurs at a radius called the critical radius; for pulsations with amplitudes greater than this critical radius, inertial forces control the collapse of a bubble and very large kinetic energy densities may occur in the liquid at the interface. The transition radius and the critical radius, which are functions of the initial size of a cavity, have been used to define a dynamical threshold for cavitation. In a motion where the maximum radius exceeds this proposed threshold, the characteristic phenomena of cavitation may be expected to appear. The dynamical threshold has in turn been used as the basis for models of cavitation bubbles useful in interpreting such phenomena.
Subject Classification: 30.70, 30.60.
Parabolic approximations for underwater sound propagation
Authors: McDaniel Suzanne T. 
Published: October 2005

Several alternative parabolic approximations to the reduced wave equation and their numerical solution are investigated for underwater acoustics applications. Parabolic approximations are derived by splitting the wave equation into transmitted and reflected components. An exact splitting operator is found, and further parabolic approximations for the transmitted fields are based on approximations to this operator. For the case of a range-independent environment, the resulting parabolic approximations are compared with normal-mode theory. The efficiency with which numerical results can be obtained is discussed, and an example of propagation from shallow to deep water is given.
Subject Classification: 30.20; 20.15, 20.40.
Elastodynamic stress intensity factors for a crack in a layered composite
Authors: Keer L. M. , Luong W. C. , Achenbach J. D. 
Published: October 2005

Elastodynamic stress intensity factors are computed for diffraction of antiplane shear waves by a crack in a layered composite. The crack is parallel to the layering. The problem is formulated by means of integral transforms, and reduced to the solution of a singular integral equation. The special case when the direction of the wave motion is perpendicular to the layering is studied numerically, and stress intensity factors are obtained for several values of frequency, material constants, and geometrical parameters.
Subject Classification: 40.55; 20.30.
Comparisons of variability in aircraft flyover noise measurements
Authors: Bishop Dwight E. 
Published: October 2005

Data from controlled flight testing conducted for 11 aircraft noise certification programs under FAA FAR 36 show typical standard deviations for sets of EPNL and PNL values ranging from 0.8 to 1.4 dB. Much greater variability was found in the noise levels measured near the approach path to runway 21R at Detroit Metropolitan Airport during two ten-day periods of routine operations. EPNL, SEL, and maximum A-level data, classified in jet aircraft groups by number of engines (regardless of type), showed typical standard deviations ranging from 3.8 to 4.9 dB at the different ground measuring points. Correlation of the Detroit noise data with slant distance gave moderately high correlation coefficients, with 95% prediction intervals about the regression lines varying from ±5.4 to ±9.5 dB. The regression lines show quite good agreement, particularly in slope, with generalized noise level versus distance curves often used for noise exposure calculations. Correlations between different noise measures were high, as expected. However, prediction intervals about the regression lines were sizable, indicating distinct possibilities for occasional sizable errors in estimating one noise measure from another when analyzing aircraft flyover noise signals.
Subject Classification: 50.50, 50.55.
Noise and sleep: A literature review and a proposed criterion for assessing effect
Authors: Lukas Jerome S. 
Published: October 2005

A brief discussion of human sleep is followed by presentation of data describing the variables that appear to affect human responsiveness to noise during sleep. Results from several studies that were conducted in different laboratories and that used several types of noises, age groups, and sexes are then combined to show that when EPNdB units are used as the measure of noise intensity, the correlation coefficient between intensity and the probability of no disturbance of sleep is −0.86. It is suggested also that a coefficient of similar magnitude would be obtained if units of EdBA were used. Some implications of these data are then exemplified.
Subject Classification: 50.70, 50.75.
Clustering of volume reverberation spectra: An application of correspondence analysis
Authors: McElroy Paul T. , Smith Woollcott 
Published: October 2005

Correspondence analysis has been applied to 34 spectral curves of volume reverberation to cluster the spectra into groups. The clustering is compared with an earlier grouping of the spectra based on the cross-standard-deviation matrix with essentially similar results. However, the correspondence analysis technique has a number of clear-cut advantages: (1) the clustering is quickly displayed in a two-dimensional plot; (2) eigenvectors computed in the analysis are spectral curves which are characteristic of extremum environments in the data set (we call them volume reverberation environments and discuss their possible indentification with preponderant fish species); (3) those frequencies which most directly serve as indicators of a particular cluster of spectra are identified; and (4) the examination of the relationship of environmental parameters and the factor scores computed in the analysis provide a basis for extrapolation of the spectra to their appearance in unmeasured conditions. The volume reverberation spectra (known as column strengths) are chosen as a particular example of the application of correspondence analysis; we believe it is broadly applicable to the problem of identifying and classifying spectra in many disciplines. As an aid to the reader in understanding the technique, we have summarized the governing equations of correspondence analysis and given a geometrical interpretation relating the original spectra, eigenvectors, and factor scores.
Subject Classification: 60.20; 30.40.
Time-frequency resolution experiment in speech analysis and synthesis
Authors: Patisaul C. R. , Hammett J. C. 
Published: October 2005

This paper reports the results of a study of the perceptual consequences of the time and frequency resolution loss inherent in vocoded speech, and an evaluation of an adaptive resolution scheme. A cepstrum vocoder which adapted its time and frequency resolution according to the voiced–unvoiced nature of the input speech was computer simulated. Speech processed by the vocoder was subjectively evaluated and several tentative conclusions regarding time-frequency resolution and speech quality were drawn. The results of the study suggest that (1) 20-msec time resolution is adequate for vocoder applications, (2) adapting to better time resolution in unvoiced regions and regions of voiced–unvoiced and unvoiced–voiced transitions leads to improved speech quality in systems that do not normally maintain 20 msec or better time resolution, (3) frequency resolution may be reduced considerably in unvoiced and transition regions with no noticeable degradation in speech quality, and (4) time-frequency resolution trading may occur in the speech perception process.
Subject Classification: 70.40, 70.55, 70.50.
Comments on ’’Ambient noise level above plane with continuous distribution of random sources’’ [L. C. Sutherland, J. Acoust. Soc. Am. 57, 1540–1542 (1975)]
Authors: Garrelick Joel M. , Kleinschmidt Klaus 
Published: October 2005

Data on the vertical gradient of noise levels outside high-rise buildings in urban areas are furnished and interpreted in terms of a hypothesis presented in Sutherland’s paper.
Subject Classification: 50.50; 28.45; 50.75.
Calculation of reverberation and average intensity of broad-band acoustic signals in the ocean by means of the RAIBAC computer model
Authors: Bachmann Wolfgang , de Raigniac Bernard 
Published: October 2005

Based on the conventional ray-tracing principle, a fast numerical algorithm is developed that calculates averaged propagation loss and reverberation of underwater sound. The averaging is performed by summing incoherently the contributions of individual ray bundles to each of the rectangular cells into which the range/depth plane is divided. The resulting matrix description of the average intensity field is used to calculate reverberation. The propagation-loss algorithm is preliminarily tested against mathematical test functions and measured data.
Subject Classification: [43]30.20, [43]30.40; [43]85.84.
Expansion of a high-pressure gas sphere in a porous medium II: Fluid compressible
Authors: Epstein David 
Published: October 2005

The work presented in an earlier paper [D. Epstein, J. Geophyos. Res. 72, 3701–3710 (1967)] on the expansion of a high-pressure gas bubble in a fluid-saturated porous medium, with the fluid treated as incompressible, is extended by treating the fluid as slightly compressible. Two limiting cases are considered: If the particulate matter is carried along with the fluid, the porous medium acts as a dense liquid, with parameters determined by simple functions of the density and compressibility of the fluid and solid particles, and the usual equations of motion apply. However, if the relative velocity of the fluid with respect to the solid is essentially equal to the fluid velocity, the motion is assumed to be governed by a compressible, generalized Darcy equation. From this equation a pair of integrodifferential equations for the bubble radius as a function of time are derived. The form of the radius-time curve depends on a nondimensional resistance factor m? = (1/2) β?/c, a combination of quantities characteristic of the fluid, the porous medium, and the gas bubble. The transition regime between ideal and Darcy flow is determined as a function of this parameter. For very small values, the bubble pulsates about the equilibrium raius ?. With increasing m?, the ratio of radiated acoustic energy to energy dissipated decreases, until the Darcy limit is reached, where bubble pulsation no longer occurs, and the expansion radius approaches ? monotonically.
Subject Classification: [43]30.60; [43]25.60.
Creeping waves and lateral waves in acoustic scattering by large elastic cylinders
Authors: Frisk G. V. , Überall H. 
Published: October 2005

The connection between creeping wave and flat surface wave theory is established by investigating the limit of acoustic scattering from a solid elastic cylinder imbedded in a fluid, as its radius tends to infinity. After applying the Watson–Sommerfeld transformation to the scattering solution, it is shown analytically that the asymptotic expressions for the residue terms (creeping waves) in the Whispering Gallery mode series combine to form separately both the longitudinal and the transverse lateral waves on a flat surface. The cylindrical Rayleigh wave tends individually towards the flat Rayleigh wave, while the Franz and Stoneley waves disappear.
Subject Classification: [43]30.35; [43]35.54; [43]20.30.
Investigation of some low ultrasonic absorption liquids
Authors: Attal J. , Quate C. F. 
Published: October 2005

We report in this paper some results on ultrasonic absorption and velocity of selected low loss liquids and mixtures which may improve the resolving power of the scanning acoustic microscope. We have investigated the effect of electrolytes as a solvent in water which serve to lower the value of α/f2 of water. We also report on our results with hydrogen peroxide and carbon disulfide for these two liquids should allow us to improve the resolution by more than a factor of 2.
Subject Classification: [43]35.24.
Multidimensional encoding within the temporal microstructure of auditory displays. III. Multistate displays
Authors: Pollack Irwin 
Published: October 2005

Multistate information was encoded within the temporal microstructure of multivariate auditory displays. Excellent discrimination of a two-dimensional constraint between interpulse interval and pulse amplitude is achieved with 2 to 16 states per variable, but only if other display variables are fixed and the range of the controlled variables is relatively large. Under most of the conditions examined, discrimination of informational constraints within multivariate displays suffers as the number of encoded states is increased beyond two.
Subject Classification :[43]65.75, [43]65.52, [43]65.22.
Psychoacoustic equivalent of period histograms [in memoriam Dr. Russell Pfeiffer]
Authors: Zwicker E. 
Published: October 2005

In masking period patterns, the SPL of a just-audible triggered sequence of short high-frequency test-tone pulses varies as a function of their temporal spacing throughout the period of a low-frequency masker. These patterns seem to be a psychocoustic equivalent of neurophysiologically measured period histograms. The duration of the test pulses resembles the bin-width of the histograms. Optimal conditions for the measurement of masking period patterns were ascertained. The influence of the test signal parameters (duration, repetition rate, and frequency) was determined. Masking-period patterns elicited by 50-, 100- and 200-Hz pure-tone maskers of different levels are described and compared with corresponding neurophysiological data. The masking-period patterns show similar periodic maxima and minima as physiological histograms, revealing the time structure of the stimulus. At high masker levels, the patterns seem to reflect nonlinear distortions. For masker frequencies higher than 100 Hz, the difference between maximum and minimum of the patterns decreases and drops to zero at about 500 Hz. This masker frequency corresponds to the psychoacoustically measured critical duration of about 2 msec, up to which the ear is able of resolving temporal fine structure. The correlation of masking-period patterns with physiological data is discussed.
Subject Classification: [43]65.58, [43]65.35, [43]65.75.
Speaker-identifying features based on formant tracks
Authors: Goldstein Ursula G. 
Published: October 2005

The formant structure of three diphthongs, four tense vowels, and three retroflex sounds was examined in detail for possible speaker-identifying features. These sounds were spoken five times each in sentence context by ten speakers of General American on one day and by six of the speakers on a second day at least three weeks later. Formant tracks were computed for each sound under investigation using covariance-type pitch-asynchronous linear prediction together with a root-finding algorithm. The interspeaker variability of about 200 measurements made on these formant tracks was compared initially with intraspeaker variability through the calculation of F ratios. Those with average F ratios greater than 60 were evaluated further with a probability-of-error criterion. Features that are potentially most effective in identifying speakers are the minimum second-formant value in [-r], the maximum first-formant value in [-r], the maximum second-formant values of [o] and [-I], and the minimum third-formant value of [-]. The individual differences apparent in these sounds presumably depend more on speaker habits than on vocal-tract anatomy. The error bound predicted for a speaker identification procedure based on these five features is 0.24%. An identification experiment using only the best two features gave 12 errors out of 80 identifications.
Subject Classification: [43]70.65, [43]70.40.
Computer optimization of transducer-array patterns
Authors: Wilson G. L. 
Published: October 2005

A linear approximation procedure has been applied to the derivation of shading coefficients for minor lobe control from symmetrical, but possibly irregularly shaped, transducer arrays, for which the relationship between the coefficients and output pressure is linear. Examples are included for the traditional problems of finding optimum coefficients for uniform and low minor lobe response from planar arrays, including one of a ’’honeycomb’’ array on a hexagonal grid, which could not be handled by analytical methods employed hitherto.
Subject Classification: [43]85.40; [43]30.85; [43]20.55; [43]85.84.