bluuebunny/crossref_metadata_2025_split huggingface dataset:
Utilization of a forced-choice technique to verify statistical performance requirements for detection systems
Authors: Buratti R. J. , Trezona G. E. 
Published: October 2005

An automated forced-choice method of evaluating detection performance is employed instead of the familiar fixed-threshold technique. The latter method utilizes a number of preselected, constant thresholds to estimate both detection and false-alarm probabilities, whereas the former incorporates a variable threshold with a precise false-alarm probability to estimate only the detection probability. The advantages of the forced-choice technique are a predetermined false-alarm rate, a single parameter test, less required test time, and real-time monitoring of test results by minimizing the amount of data reduction. A comparison of both techniques is presented for two sets of statistics which are representative of those typically encountered in detection systems under test conditions. Because of the uncertainty associated with the variable threshold, the forced-choice results are slightly pessimistic, but are within 0.3 dB of the fixed threshold results. However, the forced-choice technique can easily be made equivalent to the fixed-threshold procedure by incorporating a correction factor into the test procedure.
Subject Classification: 60.20, 60.30.
Spectrum restoration for uniformly spaced arrays
Authors: McDonough R. N. 
Published: October 2005

An ambient narrow-frequency-band acoustic field is described by the power density function N (cos ϑ), with ϑ the bearing angle from a line array of sensors. This field is observed through a conventional delay-and-sum beamformer, with average power output B (cos φ) when steered to bearing φ. We present a method (spectrum restoration) for obtaining the (wavenumber) bandlimited version of N from observed values of B. We consider only uniformly spaced arrays, and treat two computationally distinct situations: Δ &lt; λ/2 and Δ ? λ/2, where λ is the wavelength of the narrow-band field incident on the array and Δ is the array element spacing. In the former case, our method is only approximate; however, it can be carried through computationally, in contrast with methods proposed earlier, which in general succeed only for the case Δ ? λ/2. Computational results are presented for a variety of simulated noise fields, indicating sharper resolution and decreased side-lobe levels in the obtained field restoration, as compared with the beamformer response.
Subject Classification: 60.20.
Theoretical analysis of detection of monaural signals as a function of interaural noise correlation and signal frequency
Authors: Osman Eli , Tzuo Huan-yuan , Tzuo Pi-fong Lin 
Published: October 2005

Results of Wilbanks and Whitmore on the binaural detection of monaurally presented tones in broad-band noise for interaural noise correlation ranging from 0 to +1 and signal frequency ranging from 150 to 4000 Hz are reexamined. The appropriate equations and corresponding curves based on the equalization–cancellation and correlation models are compared to each other and to the equation and curves presented by Wilbanks and Whitmore. The Wilbanks and Whitmore ’’empirical ’’ equation is shown to be a special case of the correlation model equation.
Subject Classification: 65.62, 65.60, 65.58.
Speech reception with low-frequency speech energy
Authors: Rosenthal Ruth D. , Lang James K. , Levitt Harry 
Published: October 2005

The effects of low-frequency speech bands on consonant reception were investigated. A recording of the Fairbanks Rhyme Test was filtered such that four passbands were produced; a high band of 1100–2200 Hz and three low bands of 55–110, 110–220, and 220–440 Hz, respectively. Articulation scores were determined for the high band only and for the high band in combination with each of the low bands for both monotic and dichotic listening conditions. Additional data for the low-band-only conditions were also obtained. The relative gain of the low band was varied in steps of 10 dB from 0 to 40 dB. Results indicated that, compared with scores for the high band only, presentation of any one of the low bands significantly increased articulation scores and that this increase was greatest for the 220–440-Hz band in combination with the high band. An analysis of the data in terms of articulatory features showed the greatest improvement in the reception of voicing, a substantial improvement in the reception of manner of articulation, and a moderate improvement in the reception of place of articulation. Of the various consonants sampled in the rhyme test, the nasals benefited most from the additional low-frequency information. There was also a substantial improvement in the reception of plosives and the lateral, a moderate improvement in the reception of voiceless fricatives, and no measureable improvement in the reception of the glides. The relevance of these findings for the design of speech reception aids for the hearing impaired is discussed.
Subject Classification: 70.30, 70.55.
Comment on ’’Level and zero crossing in volume reverberation signals’’ [R. C. Spindel and P. T. McElroy, J. Acoust. Soc. Am. 53, 1417–1426 (1973)]
Authors: Ehrenberg John E. , Erickson Carl A. 
Published: October 2005

Spindel and McElroy [J. Acoust. Soc. Am. 53, 1417–1426 (1973)] used the zero crossings of a reverberation process to obtain an estimate of the spatial density of scatterers. Errors in their analysis resulted in an intuitively incorrect relationship between the scattering density and the reverberation zero crossing rate. The errors in their analysis are discussed, and, using a different approach, an intuitively correct expression for the zero crossing rate is derived for the special case of a rectangular sinusoidal transmitted pulse and Rayleigh distributed echo amplitudes.
Subject Classification: 30.40; 60.20.
Supplement to ’’Method of Calculation of Frequencies of Partially Fixed Beams Carrying Masses’’ [C. L. Amba-Rao, J. Acoust. Soc. Am. 40, 367–371 (1966)]
Authors: Amba-Rao C. L. 
Published: October 2005

Using finite Fourier sine transforms, it is possible to obtain frequencies and mode shapes of beams with masses and any unequal elastic restraints at the supports.
Subject Classification: 40.22.
Estimating CNC discrimination with spondee words
Authors: Bode Daniel L. , Carhart Raymond 
Published: October 2005

Five experiments with normal listeners were performed to determine the percentage of CNC monosyllables correctly identified in various presentation paradigms at the speech reception threshold (SRT) for spondee materials. The purpose was to obtain information which would allow the quick estimation from the SRT of the stimulus level yielding these CNC percentages. Descending, simple-up-and-down, and best-of-three measuring techniques were used for SRT tests, and best-of-five, doublet, and constant-level tests were employed for measuring CNC discrimination. All tests involved monaural (earphone) listening conditions in quiet or against a background of either 60 or 80 dB SPL white noise. Findings revealed that the various SRT tests estimated percentage CNC discrimination scores ranging in about 17–29% on the rising portion of articulation functions. In general, present results indicated that SRT tests are most apt to measure approximately the 23% point on CNC functions for normal listeners.
Subject Classification: 70.35.
Cancellation of turbulent boundary-layer pressure fluctuations
Authors: Kennedy Robert M. 
Published: October 2005

An optimum beamforming scheme has been applied to a system of sensors flush mounted in a turbulent boundary-layer pressure field. It is shown that flow noise propagating at subsonic velocities can be significantly discriminated against while passing, undistorted, a sonic signal. Two- and three-sensor systems are evaluated and extrapolations to a N-sensor case are made. Comparisons of the two- and three-sensor cases are made with a single sensor of finite size as well as with some previously reported results from a method by Jorgensen and Maidanik (J. Acoust. Soc. Am. 43, 1390–1394 (1968)].
Subject Classification: 30.70, 30.85.
Amplitude shading of sonar transducer arrays
Authors: Wang H. S. C. 
Published: October 2005

Amplitude shading is an important technique for controlling the beamwidth and sidelobe level of transmitting and receiving arrays in sonar and radar. The traditional method of Dolph–Tchebyscheff synthesis for the determination of array amplitude shading or weighting coefficients is, however, highly restrictive despite the extension and generalizations by many workers following Dolph. This paper outlines an entirely new method of finding these shading coefficients by minimizing the power received by the array in an isotropic noise field exclusive of a three-dimensional spatial slice around the mainbeam direction. The method is completely general in the sense that it is applicable to any discrete array of transducers arbitrarily distributed in a three-dimensional space. As an illustrative example, nonuniformly spaced linear arrays (which are necessary for reasons of economy and operation over a band of frequencies) are shown to have been successfully shaded to acceptable pattern shape and sidelobe levels. In the special case of equally spaced linear transducer arrays, the new method of shading yields an essentially identical mainbeam shape as Dolph–Tchebyscheff’s for the same sidelobe level, while the total power received (or transmitted) via the sidelobes is actually slightly less than one half of that by the latter synthesis. Necessary detailed mathematical formulas for applying the method to circular or arc arrays are also suggested.
Subject Classification: 30.82; 20.15; 60.30.
Wave propagation in nonuniform elastic rods
Authors: Rosenfeld Gerald , Keller Joseph B. 
Published: October 2005

Asymptotic solutions are obtained for elastic waves propagating in any nonuniform rod, with an arbitrary cross section which varies slowly along the length of the rod. The solutions are valid when the variation in cross section along the rod is sufficiently slow. For each mode the result is of the WKB type, involving a phase function, an amplitude function, and a mode form. The phase velocity and the mode form at each cross section are obtained from the solution for the corresponding uniform rod. The amplitude function is obtained from an equation which is equivalent to conservation of energy. An application of the results is made to long waves. The linear theory of elasticity is used throughout.
Subject Classification: 40.20, 40.22; 20.15.
Motion of a three-layered elastic–viscoelastic plate under fluid loading
Authors: Sandman B. E. 
Published: October 2005

A mathematical model of a three-layered plate structure is employed to study the vibration characteristics of a composite panel under the influence of fluid loading. The effects of heavy, in-water fluid loading is adapted in the analysis by the definition of normal and cross-coupling coefficients for the acoustic pressures which accompany the normal modes of vibration. The numerical solution is presented for relatively low-mode resonant response. The results indicate that structural stiffness and damping constitute primary factors in the resonant response and radiated pressures displayed by a finite rectangular plate. It is shown that constrained-layer damping, a normal-mode component, affects a significant reduction in the degree of cross coupling between resonant and nonresonant modes.
Subject Classification: 40.24; 20.15.
Moment impedance of internally damped rectangular and square plates with simply supported boundaries
Authors: Snowdon J. C. 
Published: October 2005

Theoretical expressions for the moment impedances of simply supported, internally damped, rectangular and square plates are presented. The plates are driven either centrally or at an arbitrary point by a bending moment, the line of action of which has arbitrary direction. In calculations made to illustrate the frequency dependence of moment impedance, plate damping of the solid type has always been assumed. The expressions for moment impedance do not contain a logarithmic term that becomes infinitely large as the separation of the moment-producing pair of forces normal to the plate surfaces is reduced to zero, and so contrast with prior expressions that have been derived for the moment impedance of infinite plates.
Subject Classification: 40.24.
Infant cry sound; developmental features
Authors: Prescott Robin 
Published: October 2005

The breath group was employed as the unit of analysis in measures of longitudinal samples of infant cry. Developmental trends were seen in decreased durations of intra-utterance silences. Small but reliable increases in intra-utterance pitch variability were observed for both longitudinal and independent samples of cry. Measures of the cries of a six-months-old hearing impaired child suggested that the above features merit further investigation as possible functions of both audition and maturation.
Subject Classification: 70.20.
Low-frequency propagation via shallow refracted paths through deep ocean unconsolidated sediments
Authors: Christensen R. E. , Frank J. A. , Geddes W. H. 
Published: October 2005

The shallow refracted path through sea floor sediments plays a significant role in the transmission of acoustic energy at low frequencies. Explosive data from three bottom acoustics stations, located in the Caribbean Sea and Bering Sea, were processed through a high-bandpass (2 to 20 kHz) filter and a low-bandpass (20 to 200 Hz) filter. Bottom returns at the high frequencies were found to be reflections. Bottom returns at the low frequencies were found to come from both reflected and refracted paths. For bottom grazing angles of 90 ° to 25 ° low-frequency acoustic energy was observed to come from reflected paths. For bottom grazing angles of 25 ° to the angle of intromission (10 °) the dominant contribution of low frequency acoustic energy comes from shallow refracted paths through the sediments. At angles less than the angle of intromission, low-frequency acoustic energy appears to be received from both the refracted and the reflected paths. The refracted path is possible because of the positive velocity gradient within the sediment. The sudden emergence of the refracted arrival is related to the overall sound path length in the sediment and sediment absorption of sound. Since sediment absorption is directly proportional to frequency, only low-frequency energy is transmitted via this path. The refracted path should exist wherever unconsolidated sediments exceed a thickness of a few hundred feet.
Subject Classification: 30.20, 30.30.
Effect of a dense gas equation of state on the expansion and contraction of an underwater gas bubble
Authors: Epstein David 
Published: October 2005

At the high pressure believed to occur in underwater explosion gases, and in cavitation gas bubble collapse, deviations from an ideal gas must be considered. A theoretical investigation into the effect of a simplified dense gas equation of state on underwater gas bubble dynamics is presented. Our approach is to make a direct comparison between ideal and dense gas results. First, the lossless, incompressible liquid case is analyzed. The requirement of a realistic equation of state yields some startling results, placing severe bounds on some of the key parameters: the peak bubble pressure, the maximum bubble wall velocity, and the minimum bubble radius. Next, nonviscous energy losses are discussed. A generalization of the Herring method is used for approximate evaluation of the radiation-loss integral derived from the Kirkwood–Bethe equation. These calculations appear to give physically reasonable loss estimates under both the ideal and dense gas assumptions. Also, an often-quoted formula for the acoustic radiation loss has been found to be in error and has been corrected. For ease in calculation of some of the important quantities of interest, useful graphs and formulas have been presented.
Subject Classification: 30.60, 30.75; 25.60.
On the flow-excited vibrations of cantilever struts in water. II. Surface-pressure fluctuations and analytical predictions
Authors: Blake William K. , Maga Lawrence J. 
Published: October 2005

Analytical predictions of the flow-excited vibration of resonant bending modes of cantilever struts are made. These predictions are compared to selected samples of measured responses of struts in a water tunnel. The measurements have been described in Part I. As a basis for the estimates, a wind tunnel study of the statistical properties of the boundary layer formed by flow on a rigid strut is described. The air measurements were made on a Reynolds-number-scaled model of one of the cantilever struts which were excited by water. For the crude geometry used, the wind results disclose that flow separation at the leading edge (which is sensitive to angle of attack) generates a low-frequency pressure field which is markedly higher than that normally encountered in boundary layers. At high frequencies the pressure field is influenced by the local flow parameters normally used in boundary-layer scaling. Predictions of the response of the struts to inflow turbulence are based on existing theory and measured water tunnel turbulence spectra. The comparisons of the calculations with the measured vibration response indicate that while the response to turbulent inflow is dominant at low frequencies, the response of the strut to its own boundary layer is important at high frequencies.
Subject Classification: 40.35, 40.22, 40.20; 30.70.
Optimal acoustic design of sandwich panels
Authors: Lang Mark A. , Dym Clive L. 
Published: October 2005

An optimization study to investigate the feasibility of an optimal acoustic design process for sandwich panels is presented here. Using a pattern search procedure it is shown that the average transmission loss of a panel may be improved through optimization over a range of frequency, and that the optimization procedure results in a shift of the panel symmetric coincidence frequency beyond the range of interest.
Subject Classification: 55.75.
Detection of underwater signals by a California sea lion and a bottlenose porpoise: variation in the payoff matrix
Authors: Schusterman Ronald J. , Barrett Barry , Moore Patrick 
Published: October 2005

A sea lion (Zalophus californianus) and a porpoise (Tursiops truncatus) were trained to report the presence of a pure tone under water in yes–no psychophysical procedures. Signal probability was held constant at 0.50. For the sea lion signal strength and payoff matrix were varied concurrently while only payoff matrix was varied for the porpoise. Payoff matrix was manipulated by changing the amount of reinforcement (number of fish) consequent on the two different classes of correct responses—hits and correct rejections. In terms of the ratio of hits to correct rejections the matrix was varied over three values—1:1, 4:1, and 1:4. In the sea lion signal detection improved as signal intensity increased and was independent of the sea lion’s response bias. In the porpoise changes in response bias occurrred as a function of changes in the payoff matrix. Both the sea lion and the porpoise repeatedly demonstrated rapid acquisition of a stable response bias. These experiments demonstrate that varying the payoff matrix may be an effective way to control response bias in experiments dealing with the detection of underwater signals by marine mammals.
Subject Classification: 80.50, 80.60.
Resonant frequencies of cylindrical Helmholtz resonators
Authors: Panton Ronald L. , Miller John M. 
Published: October 2005

A simple analysis predicts the Helmholtz and higher modes of cylindrical resonators. Formulas for the quarter-wave tube, the closed tube, and the classic Helmholtz resonator are special cases. It is found that the classic Helmholtz formula begins to lose accuracy for resonator lengths L≳λ/16. A corrected Helmholtz equation is given as an approximation to the exact result. The analysis requires values of inside and outside orifice end corrections. Rayleigh’s model of a piston in an infinite wall and Ingard’s calculations for a piston radiating into a tube give satisfactory results when the theory is compared to experiments. Resonator experiments were performed with k0L in the range π/8 to 3π/8 and orifice to cavity diameter ratios from 0.1 to 0.8.
Subject Classification: 20.40.
Comments on ’’Application of the USRD type E8 tranducer as an acoustic parametric source’’ [A. I. Eller, J. Acoust. Soc. Am. 56, 1735–1739 (1975)]
Authors: Muir T. G. 
Published: October 2005

Several practical disadvantages of the E8 as a parametric source limit its suitability as a parametric standard. The relationship of other work reported in the subject paper to previously published work is pointed out.
Subject Classification: 30.75; 25.35; 85.40.
Comments on ’’Effects of prestress on the acoustic behavior of panels’’ [C. L. Dym, J. Acoust. Soc. Am. 55, 1018–1021 (1974)]
Authors: Dym Clive L. 
Published: October 2005

The previous paper suggests that the effect of prestress on the transmission loss properties of walls could be salutory. A more detailed examination of these effects demonstrates that the gains are likely to be quite small. However, the observation that this problem couples various effects that might be thought to be unrelated is still valid.
Subject Classification: 55.75; 40.24.
Vowel perturbation as a function of tongue height
Authors: Kasprzyk Patricia L. , Gilbert Harvey R. 
Published: October 2005

Ten normal adult male speakers were asked to sustain the vowels ‖i‖, ‖u‖, ‖λ‖, ‖ae‖, and ‖a‖. A perturbation factor was then calculated for each vowel. The results indicated that no relation existed between vocal fold aperiodicity and tongue height associated with vowel production.
Subject Classification: 70.20, 70.40.
Effective length of horns
Authors: Pyle Robert W. 
Published: October 2005

Some authors writing about brass musical instruments have used the term ’’effective length,’’ usually meaning the length of a cylindrical tube having the same resonance frequencies as a given horn, but possibly with different end conditions. In this paper, alternative definitions of effective length are considered, and one definition is chosen and generalized to all frequencies, not just discrete resonance frequencies. Within the framework of lossless plane-wave horn theory, a nonlinear first-order differential equation is derived that yields effective length as a function of frequency and horn contour. Effective length has been calculated for some horn contours resembling French horns and trumpets. The solutions are qualitatively consistent with the experience of instrument makers and players, and with the effective lengths of actual instruments, determined from measured resonance frequencies.
Subject Classification: 85.60; 75.40.