bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dichotic forward and backward ’’masking’’ between CV syllables
Authors: Repp Bruno H. 
Published: October 2005

Dichotic CV syllables were presented at stimulus onset asynchronies (SOAs) between 0 and 480 msec in two ear−monitoring tasks (’’forward’’ and ’’backward masking’’). The design included indentical pairs and orthogonally varied stimulus intensities. A ’’similarity effect’’ (higher recognition scores when the target syllable contrasted on fewer features with the ’’masking’’ syllable) was found over the whole masking range (ca. 300 msec). Other findings included strong effects of both target and mask intensities, a ’’lag effect’’ but no right−ear advantage, and generally opposite effects on identical and nonidentical pairs. Identical pairs showed no masking at all. A model is suggested to account for the pattern of errors in dichotic listening: confusions are assumed to arise from nonspecific capacity limitations (’’perceptual noise’’), separately for each stimulus (hemisphere), and, at short SOAs, responses are assumed to be frequently assigned to the wrong channel. In addition, fusion may occur at very short SOAs. It is further argued that little direct interaction between dichotic inputs may take place; that central convergence occurs at a late stage in processing; that the assumption of a feature processing stage as distinct from a phoneme recognition stage may be unnecessary; and that the backward ’’masking’’ range cannot be equated with absolute processing time.
Subject Classification: 70.30.
Bulk modulus of a fluid−filled spherical shell
Authors: Hall Marshall 
Published: October 2005

The zeroth mode of vibration of a fluid−filled elastic spherical shell is examined, and a simple expression is obtained for the bulk modulus of the shell. The expression obtained is a function of the bulk moduli of the fluid and the solid, the shear modulus of the solid, and the ratio of the external and internal radii of the shell. This formula approaches the correct asymptotic values when the internal radius approaches the external radius, and also when the internal radius approaches zero. If the shell is placed in an incompressible medium, it will have a resonance frequency which is determined by the bulk modulus of the shell and the density of the medium.
Subject Classification: 40.26.
Intensity discrimination for noise bursts in the presence of a continuous, bandstop background: effects of level, width of the bandstop, and duration
Authors: Moore Brian C. J. , Raab David H. 
Published: October 2005

Weber functions for broad−band noise bursts were determined using a 2IFC procedure. Noise bursts were presented either alone or in the presence of a continuous, bandstop−filtered background whose spectrum level in the passband was 10 dB above that of the standard burst. The width of the bandstop was varied from 100 to 3160 Hz in half−log−unit steps. The center frequency of the bandstop was always 1800 Hz. Burst duration was either 10 or 250 msec, and levels ranged from 31 to 81 dB SPL. Weber fractions tended to increase with increasing level for all conditions using a bandstop background, but the effects were small. The form of the Weber function was similar for the long and the short duration bursts. Performance improved with increasing width of the bandstop, but the magnitude of the effect (on average, 2.5 dB per decade of bandwidth) was about half what would be predicted by stimulus−oriented models of discrimination (5 dB per decade).
Subject Classification: 65.35, 65.50.
Underwater localization of click and pulsed pure−tone signals by the California sea lion (Z
a
l
o
p
h
u
s c
a
l
i
f
o
r
n
i
a
n
u
s)
Authors: Moore Patrick W. B. 
Published: October 2005

The objective of this study was to measure the ability of the sea lion (Zalophus californianus) to localize click and pulsed pure−tone signals presented in the horizontal plane. In the first experiment the Minimum Audible Angle (MAA) was determined for a click signal consisting of one cycle of a 1.0−kHz signal presented with a repetition rate of 30 Hz. Thresholds at 63% and 75% correct responses were 6° and 9°, respectively. A second experiment examined the sea lion’s ability to localize pulsed pure tones ranging in frequency from 0.25 to 4.0 kHz at only one angular displacement. The pure tones were presented in the form of a pulse train, each pulse having a duration of 20 msec, rise−fall time of 5 msec, and a repetition rate of 30 Hz. The pulsed pure−tone localization function showed that as signal frequency was increased from 250 Hz to 1.0 kHz, the sea lion’s ability to localize the signal remained relatively constant, while above 1.0 kHz there was a sharp decrement in localization ability.
Subject Classification: 65.62; 80.60.
Extended modified ray theory field in bounded and unbounded inhomogeneous media
Authors: Davis James A. 
Published: October 2005

Use of the generalized WKB procedure in place of the WKB procedure to obtain solutions to the separated wave equation leads to modified ray theory. The quantitative consequences of this frequency−dependent theory are investigated and compared with ordinary ray theory and normal−mode theory for both bounded and unbounded media under conditions for the formation of a shadow region in ordinary ray theory. The behavior of the modified ray theory field, which always contains a caustic in the types of problems which are examined, depends on whether the ray theory shadow boundary is a limiting ray or a caustic. In the former case the modified ray theory field, suitably extended to take the caustic into account, approaches the normal−mode field far into the shadow region. In the latter case the modified ray theory field in the shadow region agrees with the ordinary ray theory field, also suitably extended.
Subject Classification: 30.20.
Propagation of normal mode in the parabolic approximation
Authors: McDaniel Suzanne T. 
Published: October 2005

The parabolic approximation to the acoustic wave equation is examined within the framework of normal−mode theory. For the case where sOund speed and water de pth are independent of range, three types of errors are found to occur. Discrete modes are shown to propagate with the correct amplitude and mode shape but with errors in phase and group velocities. In addition to these errors, which are inherent in the method, two other sources of error are present. The effect of these other errors may be made negligible in one case by limiting the sound−speed gradients and range considered and, in the other case, by introducing a highly absorptive layer deep in the ocean bottom.
Subject Classification: 30.20,30.50;20.40,20.15.
Speed of sound in seawater as a function of temperature and salinity at one atmosphere
Authors: Millero Frank J. , Kubinski Thomas 
Published: October 2005

The speed of sound in standard seawater (diluted with pure water and evaporated) has been measured relative to pure water with a Nusonics velocimeter as a function of temperature (0 to 40°C, at 5° intervals) and salinity (5 to 40 0/00, at 5 0/00 intervals) at a atm. The results have been fitted to an equation of the form c = c0 + A S (0/00) + B S (0/00)3/2 + C S (0/00)2, where c0 is the speed of sound in pure water, S (0/00) is the salinity in parts per thousand, and A, B, and C are temperature−dependent parameters. The sound speeds fit this equation to a standard deviation of 0.04 m sec−1 over the entire temperature and salinity range. Over the oceanographic range our results, on the average, agree with the work of Wilson to ±0.5 m sec−1 (max 1.08 m sec−1) and with the work of Del Grosso and Mader to ±0.05 m sec−1 (max 0.14 m sec−1). In the low−salinity range, (5−25 0/00 salinity) our results, on the average, agree with the work of Wilson to ±0.3 m sec−1 (max 1.1 m sec−1) and with the work of Del Grosso and Mader to within ±0.1 m sec−1 (max 0.20 m sec−1). From these comparisons it is clear that the 1−atm sound speeds of Del Grosso and Mader are more reliable than those determined by Wilson over the oceanographic range as well as at lower salinities (which is outside of the range of Del Grosso and Mader’s measurements). The adiabatic and isothermal compressibilities of seawater solutions reliable to ±0.003×10−6 bar−1 have been determined from the sound speeds. The isothermal compressibilities are in excellent agreement (avg. dev. ±0.02×10−6 bar) with the direct measurements of Lepple and Millero. The specific heat of seawater solutions at constant volume has also been determined from the sound−derived isothermal compressibilities.
Subject Classification: 30.25.
Vocalic transitions in the perception of voiceless initial stops
Authors: LaRiviere Conrad , Winitz Harris , Herriman Eve 
Published: October 2005

Two experiments were conducted in order to test the transition dependency and integration hypotheses of speech perception. These two models emphasize the importance of vocalic transitions in stop−vowel syllables for different reasons. The transition−dependency model regards the vocalic transition as a primary cue for stop identification, and the integration model holds that the transition prevents backward masking. Nine stop−vowel monosyllables were treated, resulting in a set of (1) syllables in which the vocalic transition was deleted (Experiment 1), and (2) various nonsyllabic segments—the aperiodic portion, the aperiodic portion plus the vocalic transition, the vocalic transition, and the vocalic transition plus the vowel (Experiment 2). Recognition scores obtained for these stimuli indicate that the vocalic transition is neither a sufficient nor necessary cue for voiceless stop recognition and that the aperiodic portion of the consonant carries the heaviest perceptual load.
Subject Classification: 70.30.
The orb−web as an acoustic detector
Authors: Finck Alfred , Stewart George M. , Reed Charles F. 
Published: October 2005

Movement response of the web of Araneus diadematus Cl. exhibits resonance from 20 to 30 Hz when placed in a sound field of at least 60 dB SPL. Virtually no movement of the web occurred for frequencies above 50 Hz (up to 20000 Hz). Hence it is unlikely that the orb−web serves an an acoustic detector for the approach of flying insects.
Subject Classification: 80.45, 80.50.
Basilar membrane and middle−ear vibration in guinea pig measured by capacitive probe
Authors: Wilson J. P. , Johnstone J. R. 
Published: October 2005

Measurements of amplitude and phase were made on the basilar membrane and middle ear of guinea pigs. A subminiature capacitive probe giving wide dynamic range and linearity was used in conjunction with a slave filter to provide continuous frequency response records and a lock−in amplifier to provide high−sensitivity measurements on the basilar membrane down to 40 dB SPL. The results confirm the general features of previous measurements using various optical and Mössbauer techniques but also demonstrate that the mechanical tuning properties of the basilar membrane are equally poor at low SPLs and under excellent physiological condition of the cochlea, as indicated by the threshold of the gross cochlear action potential to clicks. The basilar membrane response conforms to the differential cochlear microphonic rather than the much sharper single cochlear nerve−fiber threshold curve. Linearity of response at the peak of the mechanical curve was observed over an 80 dB range: significant nonlinearities were observed only for frequencies on the high−frequency slope, and then only for sound levels above 110 dB SPL. The existence of an amplitude and phase plateau was confirmed. The peak basilar membrane/incus ratio averaged 29 dB independent of cutoff frequency over a range from 16−43 kHz, with an rms vibration amplitude at the peak of 500 Å at 100 dB SPL over cutoff frequencies in the 16−26−kHz range.
Subject Classification: 65.20, 65.26, 65.24.
On the flow−excited vibrations of cantilever struts in water. I. Flow−induced damping and vibration
Authors: Blake William K. , Maga Lawrence J. 
Published: October 2005

The general problem of the response of a cantilever beam to flow over its surface is considered experimentally and theoretically. The model response of a beam in flowing water is shown normalized on the dynamic head of the inflow, the total mass of the beam, and the modal loss factors. Results are presented for a series of beams of varying length and chord. The magnitude of hydrodynamically induced damping is also characterized experimentally. It is shown that results agree favorably with an approximate expression based on finite aspect−ratio, unsteady airfoil theory. Loss factors, based on entrained mass, are found to be inversely proportional to a reduced frequency based on the width of the strut and inflow speed.
Subject Classification: 40.35, 40.22; 30.50.
Monostatic reflection of a plane wave from an absorbing sphere
Authors: Vogt Richard H. , Flax Lawrence , Dragonette Louis R. , Neubauer Werner G. 
Published: October 2005

The monostatic reflection from a lucite sphere in water is measured and compared with the exact classical scattering theory. Experimental results do not agree with theory which neglects absorption, in direct contrast to the excellent agreement found when metal spheres are used as targets. The theory is modified to include the effects of absorption of shear and compressional waves in lucite, and agreement between experiment and the modified theory is demonstrated.
Subject Classification: 20.30, 20.15.
Neural responses in the inferior colliculus of albino rat to binaural stimuli
Authors: Flammino Frank , Clopton Ben M. 
Published: October 2005

The responses of units in the inferior colliculus of rats were recorded while noise, tone, and click stimuli were presented binaurally. The interaural time and intensity disparities were varied; time to a maximum of 180 μsec in 30−μsec steps and intensity to a maximum of 20 dB in 4−dB steps. Total spike count, probability of firing, and average latency indicated that for most cells contralateral stimuli leading in time or of greater intensity relative to the ipsilateral ear produced increased spike counts and probability of firing and decreased latency of firing. While support is apparent for the influence of both time and intensity cues, the intensity cue would seem to predominate under naturally occuring conditions. A population model for the utilization of these two cues is supported by the data.
Subject Classification: 65.44, 65.62.
Duration−intensity reciprocity for equal loudness
Authors: McFadden Dennis 
Published: October 2005

Magnitude estimates were obtained for a 1000−Hz tone presented at all combinations of seven different intensities and seven different durations. Power functions were plotted for each duration separately. These functions were horizontally intersected at several different values of judged magnitude, and the intensities necessary for equal judgment were determined and then plotted as a function of duration. The latter functions, which are analogous to classical acoustic−integration curves, indicate that for equal judged loudness, intensity must be decreased by between 3 and 15 dB for each doubling of duration, depending upon the subject. Thus, for some subjects the acoustic−integration curves for loudness are much steeper than those typically obtained using more conventional techniques.
Subject Classification: 65.50, 65.75.
Comments on ’’Analysis of class IV flextentional transducer by use of wave mechanics’’ [Gerald H. Brigham, J. Acoust. Soc. Am. 56, 31–39 (1974)]
Authors: Lubell Alan H. 
Published: October 2005

The purpose of this communication is to point out errors in Sec. III of this very interesting paper and to suggest that the theory of compliance loading [Alan H. Lubell, J. Acoust. Soc. Am. 35, 1905(A) (1963)] might possibly be of use in improving the performance flextentional transducers.
Subject Classification: 30.85.
Statistical properties of wind over the coast and its stochastic model
Authors: Sato Takuso , Sasaki Kimio , Mori Akira 
Published: October 2005

The statistical properties of the force of the wind over the coast observed at a fixed point were analyzed by using the bispectrum as well as the power spectrum. The results show that the fluctuation of the wind force, which is regarded as a stochastic signal, is strictly non-Gaussian. As a proper stochastic model of the wind force, the output random signal of a low-pass filter excited by a Poisson impulse sequence is proposed.
Subject Classification: 45.10.
Beat-like interaction between periodic waveforms
Authors: McFadden Dennis 
Published: October 2005

It is possible to hear a beat-like interaction between the envelopes of two two-tone complexes, or between the envelope of a two-tone complex and a tone of lower frequency. This monaural effect can be explained as a modulation of the traveling-wave envelope of the higher-frequency complex by the lower-frequency waveform.
Subject Classification: 65.62, 65.60, 65.56.
Harmonic wave propagation in composite materials
Authors: Nelson Richard B. , Navi Parviz 
Published: October 2005

This paper presents a study of the propagation of harmonic waves of plane strain in elastic composite materials. The composite structure is idealized as an assembly of identical subregions, each with the displacement field represented by a finite number of generalized displacements. The resulting model possesses a periodic lattice-type structure and its response to harmonic waves can be investigated as a problem in lattice dynamics. A set of generalized coordinates, applicable for the case of harmonic wave propagation in the discrete periodic structure, is employed to generate an algebraic eigenvalue problem, the solution of which gives the frequency spectrum for the medium. To show the accuracy of this method, examples of harmonic wave propagation in infinite isotropic and orthotropic homogeneous plates are presented, and cases of harmonic wave propagation in infinite isotropic and orthotropic media. The method is used to generate the frequency spectra for both a fiber-reinforced composite plate and an infinite composite medium to clearly indicate the dispersive effects which exist in periodic media when the half wavelength–lattice dimension ratio approaches unity. These results are compared with several well-known theories for composite materials.
Subject Classification: 20.15.
Experimental investigation of several passive sonar targets
Authors: Wallace R. H. , Hillery H. V. , Barnard G. R. , Marks B. M. , McKinney C. M. 
Published: October 2005

This paper presents the results of an experimental investigation of several passive sonar targets of the types used for calibration, marking, and tracking. Targets studied include spheres, spherical lenses, triplanes, icosahedrons, biconics, and some composite types designed to have specific frequency responses. It is concluded that, of the targets investigated, only the accurately made sphere and spherical lens are suitable for use as calibration standards under the condition of the target being supported by a flexible line. The various corner reflector configurations are suitable for marking, navigation, and tracking. The feasibility of designing passive targets with a specified frequency response is demonstrated.
Subject Classification: 30.30, 30.50.
Dispersion of acoustic waves by fiber-reinforced viscoelastic materials
Authors: Sutherland Herbert J. 
Published: October 2005

Acoustic waves are dispersed by two distinct mechanisms as they propagate through a fiber-reinforced viscoelastic material. The first mechanism, viscoelastic dispersion, is characterized by an increase in phase velocity with an increase in frequency, and the second mechanism, geometric dispersion, is characterized as a wave-filtering phenomenon in which periodic waves are selectively transmitted and reflected. To study the interplay between these two mechanisms, the dispersion characteristics of two fiber-reinforced viscoelastic materials were obtained at various temperatures using a water-bath technique. The first composite studied was a cloth-laminate quartz phenolic (2D-QP). Its dispersion characteristics (both phase velocity and attenuation versus frequency) were obtained at seven temperatures, ranging from 4 ° to 40 °C. The second material studied was stainless steel wires embedded in an Epon 828-Z matrix (Epon–SST). Its dispersion characteristics (phase velocity versus frequency) were determined at five temperatures, ranging from 5 ° to 42 °C. The characteristics of these two materials at their low-frequency limits are similar; namely, the phase velocity decreases with increasing temperature. There, the similarity ends. The relatively fine structure of the 2D-QP is weakly dispersive below 4 MHz, and viscoelastic dispersion dominates; whereas the relatively coarse structure of the Epon–SST is highly dispersive below 2 MHz (the cutoff frequency of the first passband was found to be about 1 MHz and this composite behaves as a wave filter.
Subject Classification: 35.26, 35.50.
Hypersonic absorption and velocity in molten potassium nitrate
Authors: Torell Lena M. 
Published: October 2005

The spectrum of light scattered from thermal sound waves has been studied by Brillouin spectroscopy in molten potassium nitrate to provide information about the hypersonic velocity and the absorption of thermal waves. Brillouin spectra were investigated in a temperature range of 350–600 °C for scattering angles of 40 °–140 ° to determine the variation of the phonon velocity and attenuation as a function of temperature and frequency. The measurements did not reveal any difference between the sound velocities at a scattering angle of 40 ° (3 GHz) and at 140 ° (10 GHz), but the hypersonic velocities were all higher than the ultrasonic ones. In spite of this fact, considerable decrease in attenuation was observed within the investigated frequency interval, with the value at high frequency approaching the classical limit attributed to shear viscosity. These results indicate a relaxation frequency just below the measured frequency range. The relaxation time for the bulk viscosity coefficient was determined from two independent measurements: (1) the position of the Brillouin lines and (2) the width of these lines. A relaxation theory involving a single relaxation time has been applied and agrees with the experimental results.
Subject Classification: 35.24, 35.35.
Real and imaginary parts of the complex viscoelastic modulus for boron fiber reinforced plastics (BFRP)
Authors: Paxson Ernest B. 
Published: October 2005

The general viscoelastic model was chosen to represent the mechanical properties of boron fiber reinforced plastic (BFRP). The experimental configuration selected was that of a thin beam subjected to transverse vibration. The mechanical properties of the beam (in the direction x parallel to the length of the beam) then manifest themselves in the form of a viscoelastic complex modulus E*xx = E\xx + iE\xx. In this investigation the purposes were to measure E′xx and E\xx (and the loss factor) for BFRP and to compare the loss factors for BFRP with that for a metallic material such as aluminum 2024-T4 alloy. Boron laminates used in these studies were fabricated from NARMCO 5505 preimpregnated boron fiber epoxy tape. Values of storage modulus E′xx and loss modulus E\xx as a function of excitation frequency are presented for three fiber orientations, 0 ° (undirectional), ±45 ° (crossply), and 90 ° (all transverse). Also presented is the damping (or loss) factor ηxx as a function of excitation frequency for the three above-mentioned fiber orientations. The values obtained for damping factor are compared with those obtained by measuring exponential decay of BFRP beams initially excited in the free–free mode of vibration.
Subject Classification: 40.60, 40.22.