bluuebunny/crossref_metadata_2025 huggingface dataset:
Consonant duration in American English
Authors: Umeda Noriko
Published: October 2005

The paper discusses the temporal behavior of all measurable consonants, detailed in all possible conditions, in an extensive reading by one speaker. The data indicate a strong parallelism in duration distributions among similar kinds of consonants, and interesting similarities and differences between different kinds of consonants in terms of phoneme-sequential constraints and higher-level linguistic factors.
Origin and character of vascular murmurs: Model studies
Authors: Fredberg Jeffrey J.
Published: October 2005

The fluctuating mechanical stress imposed upon the arterial-wall downstream of a stenosis by turbulent blood flow was studied in a model experiment. The dependence of mean-square wall pressure and spectral density of wall pressure upon Reynolds number, diameter ratio, and distance from the stenosis was obtained. The mean-square pressure was found to have strong Reynolds-number dependence at low Reynolds number, and the distance downstream of the stenosis at which the mean-square fluctuating pressure reaches its maximum intensity was found to depend upon jet velocity and fluid viscosity only. A high Reynolds-number scaling of the spectral density of wall pressure was obtained.
On presenting a technical paper
Authors: Young Robert W.
Published: October 2005

The typed script for a 12-min technical talk is likely to occupy not more than five pages, double spaced, in elite type. Time may limit the presentation to six slides. Lettering on a figure for a slide should be 1/40 the height of the figure.
Difficulties of choosing a frequency for miniature transmitters in fresh water
Authors: Pincock Douglas
Published: October 2005

It is shown that the choice of a suitable operating frequency for miniature acoustic transmitters depends crucially on a knowledge of absorption and noise characteristics of the water. For application in fresh water, imperfect knowledge of these characteristics can result in incorrect frequency choice giving serious reductions in range capability for the transmitting power available.
Phase-locked loop device for the fine frequency analysis of the biosonar signals of bats
Authors: Smith David M. , Mercer Robert , Goldman L. J. , Henson O. W. , Henson Miriam M.
Published: October 2005

A new device is described for the frequency analysis of the ultrasonic pulses emitted by constant frequency bats. The instrument employs a phase-locked loop and is capable of resolving frequency shifts as small as 20 Hz. The instrument responds to instantaneous frequency changes within 120 μsec.
Interpretation of radiation fields in terms of sub-beams
Authors: McCoy J. J.
Published: October 2005

Two frequently employed measures of a statistical radiation field, i.e., the mutual coherence function and the acoustic-intensity angular spectral density, are considered as they apply to deterministic beamed signals. Mathematical formulations, in the form of differential equations, that govern the propagation of these measures had previously been presented [J. J. Mcloy and M. J. Beran, J. Acoust. Soc. Am. 59, 1142–1149 (1976)]. Here, we show that solutions of these formulations suggest an interpretation of a radiation field in terms of sub-beams. These sub-beams are the natural extensions of the ray tubes of the geometric theory. In the Appendix we consider the relationships between the acoustic-intensity angular spectral density and other more commonly encountered measures of a radition field.
Sound transmission through periodically framed parallel plates
Authors: Lin Gau-Feng , Garrelick Joel M.
Published: October 2005

The problem of transmission of a plane sound wave through two infinite parallel plates connected by identical periodically spaced frames is solved. Fluid loading within and without the cavity space is taken into account. Numerical results are presented corresponding to a standard double-walled partition. The strengths of the two parallel transmission paths, i.e., the structural path through the studs and the airborne path through the cavity space, are compared.
Masking-period patterns produced by very-low-frequency maskers and their possible relation to basilar-membrane displacement
Authors: Zwicker E.
Published: October 2005

By using masking-period patterns (MPP), produced by sinusoidal as well as impulsive maskers with very-low-frequency components, it could be demonstrated for man that the basilar membrane seems to move in phase for low sinusoids and preserves the waveform for nonsinusoids with low-frequency spectrum within the two basal turns of the cochlea. The shape of a MPP is strongly correlated to the second derivative of the time function of the sound pressure at the eardrum for frequencies below 40 Hz, but to the first derivative for frequencies above 40 Hz. This is presumably due to the form of the cross section of the cochlea and the size of the helicotrema in man. Data of many MPP are shown and discussed together with patterns given in former papers on a qualitative and a quantitative level, leading to the following proposal: the higher peak in MPP belongs to a kind of suppression which would correspond to the displacement of the basilar membrane towards scala tympani, while the lower peak in MPP belongs to the excitation which would correspond to the displacement of the basilar membrane towards scala vestibuli.
Video-scanning system for measurement of lip and jaw motion
Authors: McCutcheon Martin J. , Fletcher Samuel G. , Hasegawa Akira
Published: October 2005

An instrument for measuring labial and mandibular positions during speech is described. A modified video system is used to measure the positions of small reflecting glass beads attached at selected points on the face and to a thin wire anchored on a mandibular tooth. The system allows continuous data collection from up to 16 reflector points at a sampling rate of 100 Hz. Reflector movements with instantaneous velocities up to 45 cm/sec can be determined with a 0.3-mm resolution. Techniques for data acquisition and analysis and display are described.
Nonlinear inverse filtering technique for estimating the glottal-area waveform
Authors: Rothenberg Martin , Zahorian Stephen
Published: October 2005

Linear time-invariant inverse filtering of the pressure or airflow signal at the mouth during voicing has often been used to provide a reasonable representation of the airflow waveform at the glottis. However, if the glottal impedance, as it varies during the glottal cycle, does not remain much larger than the impedance of the supraglottal vocal tract, the resulting glottal-supraglottal acoustic interaction may make the glottal airflow a poor representation of the motion of the vocal folds. An inverse filter is described here for deriving from oral airflow the Norton equivalent airflow of the glottal source, which is a better estimate of the glottal area than the actual airflow. This inverse filter is nonlinear in that certain filter parameters are varied dynamically, so as to compensate for the time variation of the glottal resistance and inertance. Using a feedback procedure, estimates of these glottal parameters are obtained from the filter output waveform. Results from such nonlinear inverse filtering support the conclusion that the nonlinear glottal-supraglottal interaction may be a significant factor in determining the spectral content of the glottal pulse, and for some types of voice, in causing the primary excitation of the vocal tract to occur at the closing of the vocal folds.
Electric and acoustic waves in continuously coupled distributed coupling transducers
Authors: Zalesak Joseph F.
Published: October 2005

A distributed coupling transducer consists of an electric and an acoustic transmission line continuously and reversibly coupled to each other. The operation of this device is described by four coupled first-order differential equations. The solution to these equations is obtained in closed form for both infinite and finite transmission-line systems. The example of a side-plated piezoceramic bar is considered in setting up the equations. A comparison between the complete theory and an approximation based on the infinite transmission line is given. Some aspects of the design of a high-efficiency, broadband electroacoustic transducer with a relatively constant resistive electrical driving-point impedance are presented.
Approximate formulas for natural frequencies of rectangular plates with linearly varying thickness
Authors: Sakata Toshiyuki , Sakata Yoshiko
Published: October 2005

A characteristic equation is derived analytically for a rectangular plate with thickness varying linearly in one direction by using the trigonometric series. Boundary conditions of the plate are simply supported along two opposite sides, free along one side and simply supported or free along the remaining side. By using the results computed numerically from the characteristic equation, approximate formulas are derived for estimating accurately the fundamental natural frequency of the plate.
Estimation of sonar target transfer functions in the presence of clutter and noise
Authors: Altes R. A.
Published: October 2005

Optimum transmitted signal and receiver filter functions are derived for estimation of a sonar target’s impulse response in thes presence of noise and clutter (reverberation).The addition of clutter represents a generalization of a problem that has already beena solved by G. L. Turin. The solution to the generalized problem is to multiply Turin’s signal and filter spectra by the square root of a Wiener filter function that gives a best estimate of the target echo in the presence of clutter.
Determination of masking-level differences in a reverberant environment
Authors: Koenig A. H. , Allen J. B. , Berkley D. A. , Curtis T. H.
Published: October 2005

A masking-level-difference (MLD) paradigm was used to measure release from masking in a reverberant environment. The masking-level difference is specified in terms of the signal level in decibels at threshold for an experimental condition, relative to the signal level at threshold for the reference S0N0 condition where the maskee and masker are both binaurally in phase. Two types of masking situations were used: (1) incoherent masking—a signal (pulsed tone or speech in this study) had to be detected in a noise background; (2) coherent masking—the signal and masker were derived from the same source. Band-limited noise and speech were used in the coherent masking experiments. For both masking conditions, the MLD was found to be approximately 3 dB. Cross correlation of the late-echo structure of impulse responses taken at the left and right ears of a manikin show that the reverberant sound field is uncorrelated between the two ears. This is consistent with a 3-dB MLD result.
Calculation of electroacoustic sensitivity of radially polarized ferroelectric cylinders by normal-mode methods
Authors: Sabbagh Harold A.
Published: October 2005

The theory of electroacoustic N ports, together with the theory of electroelastic normal modes, is applied to the calculation of the electroacoustic sensitivity of radially polarized, thin, ferroelectric shells. Electroelastic, short-circuit, normal modes are computed by solving the simplified one-dimensional approximate equations of thin-shell theory, and the results are used to compute the admittance-matrix elements of an N-port representation of the shell. Once the admittance-matrix elements have been computed, the calculation of the open-circuit sensitivity follows from a straightforward application of N- port theory. Computations of the open-circuit sensitivity of capped, uniformly polarized and bipoled shells are made as a function of frequency. The result is that the bipoled shell has 6 dB greater sensitivity than does the uniformly poled shell. In addition, our calculations indicate the frequency range over which one can reasonably use classical, low-frequency results. The paper concludes with the calculation and discussion of electroelastic, open-circuit, normal modes of the uniformly poled shell.
Regional dependence of low-frequency attenuation in the North Pacific Ocean
Authors: Kibblewhite A. C. , Bedford N. R. , Mitchell S. K.
Published: October 2005

A number of experiments based in the South Pacific Ocean have now been reported in which the attenuation of underwater sound at very-low-frequencies displays an apparent regional dependence, providing a possible explanation for the considerable spread in at sea attenuation measurements below 1kHz. This regional dependence has been interpreted in terms of acoustic scattering from oceanographic inhomogeneities of various forms, and at least two recent theoretical variants based on such a mechanism have been proposed. This paper presents evidence of a similar regional dependency in the North Pacific Ocean and examines the significance of the data to the two theoretical treatments currently most successful in accounting for the effects observed.
Acoustic Doppler extraction by adaptive linear-prediction filtering
Authors: Keeler R. Jeffery , Griffiths Lloyd J.
Published: October 2005

Acoustic echo sounders can be used to measure wind profiles in the lower atmosphere by estimating the Doppler shift from the range-gated received echoes. Instantaneous frequency estimates are estimated from the coefficients of an an adaptive linear- prediction filter (ALPF). These coefficients are updated at each sample time and provide a current estimate of the spectrum of the scattered acoustic echoes. The adaptive algorithm is derived in the context of a whitening filter and its convergence is shown to be rapid enough to track the vertical profile of wind in the lower atmosphere. An ALPF-derived profile is shown superior to an FFT-derived profile in both computational speed and estimator accuracy.
N-path first-order digital impulse correlator
Authors: Kerr D. E. , Lengyel M. W.
Published: October 2005

An N-path digital-filter approximation to the impulse correlator is developed. The high processing gain provided by impulse correlation makes it possible to clearly extract complex periodic signals from noise. The analogy between the impulse correlator and the N-path digital filter is examined. It is shown that the N-path filter approximates the impulse correlation with sufficient accuracy to be used for recovery of complex periodic signals from noise.
Investigation of several aspects of low-frequency (200 Hz) central masking
Authors: Billings Bradley L. , Stokinger Thomas E.
Published: October 2005

The frequency spread, temporal relations, and growth of central masking were investigated using low-frequency maskers (200 Hz) to further define the effects of cochlear mechanics on central-masking phenomena. The maskers were either steady state or gated with a duration of 500 msec, presented at 10, 30, and 50 dB SL. The maskees were brief, gated tone bursts from 170 to 4000 Hz and were located at the onset of the gated maskers or equidistant between the onset and offset of the gated maskers. The temporal relations and growth of central masking measured in this study are similar to results published by other authors using higher-frequency maskers. The low-frequency spread of central masking measured in this study, however, exceeded four octaves above the masker frequency. This result is considerably different from the typical narrow spread of central-masking functions reported for higher-frequency maskers. Therefore, central-masking phenomena appear to be significantly affected by cochlear transduction of the masker and maskee signals, as well as being a function of central auditory neural interactions.
Spectral cues utilized in the localization of sound in the median sagittal plane
Authors: Butler Robert A. , Belendiuk Krystyna
Published: October 2005

A series of experiments was carried out to further elucidate the role of spectral cues in locating sounds in the median sagittal plane (MSP). Broadband noise bursts, generated at ±30°, ±15°, and O° re aural axis, were recorded via microphones placed in the external ear canals of 8 Ss. When these recorded sounds were played back dichotically through headphones, they were perceived as originating from the loudspeakers, not the headphones. In fact, Ss could identify that loudspeaker which originally generated the sound nearly as accurately as they could when listening under free-field conditions. Analysis of the spectra of these recorded sounds revealed a notch in the frequency response curves which migrated toward the lower frequencies as the sound source was moved from above to below the aural axis. This feature of the spectrum may well be important for accuracy in locating sounds emanating from the frontal segment of the MSP. Four Ss were given additional tests to find out whether they could locate sounds recorded from one another’s ear canals. All Ss immediately externalized the recorded sounds. However, differences between performances among the various tapes of recorded sounds were statistically significant, suggesting that spectral cues provided by some Ss were more efficacious than others in furnishing information on the elevation of sound sources.
Multidimensional perceptual scaling of musical timbres
Authors: Grey John M.
Published: October 2005

Two experiments were performed to evaluate the perceptual relationships between 16 music instrument tones. The stimuli were computer synthesized based upon an analysis of actual instrument tones, and they were perceptually equalized for loudness, pitch, and duration. Experiment 1 evaluated the tones with respect to perceptual similarities, and the results were treated with multidimensional scaling techniques and hierarchic clustering analysis. A three-dimensional scaling solution, well matching the clustering analysis, was found to be interpretable in terms of (1) the spectral energy distribution; (2) the presence of synchronicity in the transients of the higher harmonics, along with the closely related amount of spectral fluctuation within the the tone through time; and (3) the presence of low-amplitude, high-frequency energy in the initial attack segment; an alternate interpretation of the latter two dimensions viewed the cylindrical distribution of clusters of stimulus points about the spectral energy distribution, grouping on the basis of musical instrument family (with two exceptions). Experiment 2 was a learning task of a set of labels for the 16 tones. Confusions were examined in light of the similarity structure for the tones from experiment 1, and one of the family-grouping exceptions was found to be reflected in the difficulty of learning the labels.
Detection of a tone burst in continuous- and gated-noise maskers; defects of signal frequency, duration, and masker level
Authors: Wier Craig C. , Green David M. , Hafter Ervin R. , Burkhardt S.
Published: October 2005

Gated-noise maskers produce more masking of a tone burst than do continuous-noise maskers. The difference between the two conditions appears to increase at short signal durations with a maximum difference at about 1000 Hz. The size of the effect is generally small, 1–3 dB, reaching a maximum of 4–7 dB for 1000 Hz at 10 msec and high masker levels.
Property detectors for bursts and transitions in speech perception
Authors: Blumstein S. E. , Stevens K. N. , Nigro G. N.
Published: October 2005

A series of adaptation experiments was conducted to investigate the role of initial noise bursts and transitions as cues to place of articulation in stop consonants. A test continuum was constructed consisting of 14 synthetic stimuli in which the transitions of formant two and formant three were systematically varied to range along the [b d g] phonetic dimension. The adapting stimuli consisted of full-cue stimuli in which place of articulation was signaled by burst as well as transitions; partial-cue stimuli in which place was signaled by transitions only; and conflicting-cue stimuli in which the burst frequency signaled one phonetic dimension (e.g., [d]), whereas the transitions signaled another (e.g., [g]). Adaptation with either the partial- or full-cue stimuli produced significant shifts in phonetic boundaries for the test continuum, with the full-cue stimuli producing a slightly greater boundary shift. The conflicting-cue stimuli produced no significant shifts in adaptation. Moreover, adaptation effects seemed to be a function of the acoustic attributes of the stimulus independent of the phonetic label given the stimulus by the subject. These results were interpreted in terms of a model that postulates a set of integrated properties characterized by the short-term acoustic spectrum sampled at the abrupt amplitude discontinuity at consonantal release, and a set of simple properties consisting of individual attributes of the test stimuli such as burst frequency.
Development of a test of speech intelligibility in noise using sentence materials with controlled word predictability
Authors: Kalikow D. N. , Stevens K. N. , Elliott L. L.
Published: October 2005

This paper describes a test of everyday speech reception, in which a listener’s utilization of the linguistic-situational information of speech is assessed, and is compared with the utilization of acoustic-phonetic information. The test items are sentences which are presented in babble-type noise, and the listener response is the final word in the sentence (the key word) which is always a monosyllabic noun. Two types of sentences are used: high-predictability items for which the key word is somewhat predictable from the context, and low-predictability items for which the final word cannot be predicted from the context. Both types are included in several 50-item forms of the test, which are balanced for intelligibility, key-word familiarity and predictability, phonetic content, and length. Performance of normally hearing listeners for various signal-to-noise ratios shows significantly different functions for low- and high-predictability items. The potential applications of this test, particularly in the assessment of speech reception in the hearing impaired, are discussed.
Uncertainty concerning the direct use of time information in hearing: Place clues in white-spectra stimuli
Authors: Pierce J. R. , Lipes R. , Cheetham C.
Published: October 2005

Data on time response in the nervous system are available for animals. Rate-matching data for humam subjects with implanted electrodes are available. These data do not tell us with certainty up to what rate people with normal hearing utilize time information directly. In many experiments an attempt to measure time response is confused by the presence of spectral clues. Short-term spectral clues exist in stochastic sequences of positive and negative pulses and in modulated white noise, both of which have a white long-term spectrum. These clues are periodicity (with a period equal to the pulse or modulation rate) and symmetry (about frequencies equal to integer multiples of half this rate), differences at different frequencies in the peak- or rms-voltage distribution function of the output of a narrow-band filter and, in the case of stochastic pulse sequences, differences in extreme intensity at different frequencies. It may be that the ability to match at high rates and the perception of tonal quality that subjects with excellent and trained hearing, such as musicians, exhibit for white-spectrum stochastic pulse sequences or gated noise is due to the residue phenomenon or to spectral clues discussed in this paper.
Acoustic properties of voice timbre types and their influence on voice classification
Authors: Cleveland Thomas F.
Published: October 2005

An investigation to determine the significance of formant frequencies, pitch, and source-spectrum slope on voice classification is reported. Eight professional singers sang five common vowels on four common pitches, and, in a forced-choice test, vocal pedagogues classified the vocalization as tenor, baritone, or bass. Formant frequency and pitch differences accounted for most of the jury- evaluation results. To evaluate more accurately the significance of formant frequencies, pitch, and voicing and source-spectral slope on voice classification, vowel synthesis was employed. Measurements of spoken vowel vocalizations revealed higher formant frequencies in tenor timbre type and lower formant frequencies in bass timbre type. Long-time-average spectra seem to afford a good estimate of voice classification. Formant-frequency percentage differences between basses and tenors were similar to those found between males and females, suggesting that the mouth and pharynx lengths, known to differentiate females and males, probably also differentiate tenors and basses.
Multidimensional classification of abnormal voice qualities
Authors: Murry Thomas , Singh Sadanand , Sargent Margaret
Published: October 2005

This study demonstrates the application of a multidimensional scaling technique, known as INDSCAL, to determine the perceptual attributes of a group of non-normal voices. In this study, equal-appearing interval scale was used to obtain judgments of similarity for 20 speakers sustaining a vowel. For each speaker, six physical and three psychophysical measures were also obtained and used to interpret the INDSCAL solution. A five-dimensional solution was found to be the most appropriate solution for explaining the variance. The findings of the INDSCAL analysis suggest that there exist distinct perceptual features of the abnormal voice which have physical and psychophysical correlates. The strengths of the underlying dimensions of the voices appear to indicate that multidimensional scaling will be a valuable tool in the diagnosis of voice abnormalities.
Extensions on ’’Cancellation of turbulent boundary-layer pressure fluctuations’’ [R. P. Kennedy, J. Acoust. Soc. Am. 57, 1062–1066 (1975)]
Authors: Bordelon Derrill J.
Published: October 2005

Robert Kennedy’s calculations on applications of optimal beamforming to turbulence-noise cancellation are extended to the case of an arbitrary number of equispaced collinear point sensors. A limiting expression is obtained for a factor that provides the amount of reduction of the flow noise component to the output. Additionally, the arguments corresponding to the first two minima of this factor are also computed.
Comments on ’’Environmental effects on microphones of various constructions’’ [J. Acoust Soc. Am. 61, 206–210 (1977)]
Authors: Kundert Warren R.
Published: October 2005

This paper purports to compare the effect of temperature and humidity on three different types of microphones; air-cpndenser, electret-condenser, on three different types of microphones; air-condenser, electret-condenser, and ceramic. One type, the air condenser, is ’’back vented through a d dehumidifier’’ and is thus not really exposed to humidity. It is not surprising to find that it is unaffected by humidity when protected in this way. Tables that are alleged to demonstrate long-term stability show changes in sensitivity that are probably due to residual moisture in the microphones.
Linear ultrasonic array design for echosonography
Authors: Miller E. B. , Thurstone F. L.
Published: October 2005

Phased-array echosonographic systems, currently in use in medical diagnosis, employ pulses that are a few wavelengths long at the center frequency. Design of such systems requires that arrays be composed of as few elements as are consistent with acceptable resolution and low side lobes. This paper outlines the development of a model for the field of an idealized phased array. The model is an extension of elementary array theory which includes pulse parameters and beam steering. It is specialized for the generation of simple and useful directivity patterns that are applicable at point focal regions and in the farfield. The directivity-pattern function provides the basis for a method of designing linear arrays by nonuniform element spacing. Arrays designed by this method offer advantages over uniform linear arrays because of the smaller number of elements required for given azimuthal resolution and side-lobe level, and because of reduced element interaction.
Active sound absorption
Authors: Mangiante G. A.
Published: October 2005

Sound attenuation is usually obtained by means of absorbing materials. This technique, which works quite well for sounds of medium and high frequencies, is very inefficient at low frequencies, because the thickness of absorbing material necessary to produce a constant attenuation increases with decreasing frequency. There is another technique by which destructive interference is used to silence sound fields: it is active sound absorption. Hitherto, this was based on Young’s principle of interference. This paper proposes a general theory, using Huygens’ principle, for three-dimensional sound-wave propagation. Some experiments are also reported and discussed.
Short-wavelength diffracted surface pressures on a rigid prolate spheroid
Authors: Blake William K. , Wilson George A.
Published: October 2005

This paper will describe measurements of sound pressures on the surface of a prolate spheroid whose length-to-diameter ratio is 6:9. The sound source was positioned a distance from the illuminated pole equal to the length of the body; irradiation was axisymmetric. Data at surface locations along the axis of the body was collected for acoustic wavelengths λ ranging from 1/150 to 1/38 of the interfocal distance d. A condenser microphone equipped with a long probe tube was used to avoid extraneous scattering from the sensor. Sound pressure levels, expressed relative to those measured on the illuminated pole, showed the existence of expected creeping-wave interference patterns near the antipode and an illuminated spot on the pole. The measured levels on that pole are shown to decrease roughly as the reciprocal of frequency; they are 13 dB less than those at the illuminated pole for d/λ=38. In the shadow zone the measurements are shown to be well approximated by Keller’s geometric theory of diffraction. Deviations from the theory on the order of 3 dB are observed at high frequencies and at coordinates off the antipole.
Radiation from the open end of a cylindrical or conical pipe and scattering from the end of a rod or slab
Authors: Ting Lu , Keller Joseph B.
Published: October 2005

The radiation of sound through the open end of a cylindrical or conical pipe of any cross section, or through a hole in a plane wall, is analyzed theoretically. The scattering of a sound wave by the end of a rod or slab is also treated. Only the case in which the wavelength λ is large compared with a typical radial dimension a of the opening or of the end, is considered. The method of matched asymptotic expansions is employed. Results on end corrections and reflection coefficients previously obtained by Helmholtz, Rayleigh, and Bazer and Karp using intuitive arguments are recovered and verified. Agreement is found with the exact results of Levine and Schwinger and Vainstein, and with the small a/λ results of Lesser and Lewis, in the cases they treated. In addition various new results are obtained.
Comparison of two solutions for acoustic radiation pressure on a sphere
Authors: Hasegawa Takahi
Published: October 2005

The expression obtained by Hasegawa and Yosioka [J. Acoust. Soc. Am. 46, 1139–1143 (1969)] for the acoustic radiation pressure on a solid elastic sphere in a plane progressive sound field is reformed into a simpler form, in which the acoustic-radiation-pressure function is represented only in terms of scattering coefficients and the size parameter ka. On the other hand, the extension of the Maidanik calculation [J. Acoust. Soc. Am. 29, 936–940 (1957)] for a fluid sphere to solid elastic spheres is attempted. The result is compared with the former. It is demonstrated that the computational differences are commensurate with the same result.
Some acoustical properties of floating-floor constructions
Authors: Nilsson A. C.
Published: October 2005

Expressions giving the velocity level difference between bottom and top plates are derived. Calculated and measured values are compared. The frequency dependence of the level difference is found to be between 25 and 40 dB/decade. The slope of the curve depends on the material parameters for the floor. Radiation ratios and reduction indices for some floating-deck constructions are also discussed.
Transformation characteristics of the external human ear
Authors: Mehrgardt S. , Mellert V.
Published: October 2005

With an impulse response technique the transfer functions from the free sound field to the ear-canal entrance were measured on 20 subjects for sound incidence from ten directions of the symmetry plane and 20 directions of the horizontal plane. Separate for each direction amplitude and phase of these transfer functions were averaged using a technic, which yields mean values still containing fine structures of single measurements. Additionally the transfer function of the ear canal was measured on three subjects. The eardrum impedance was then computed from this transfer function and completes the poor knowledge of the eardrum impedance in the frequency range from 2 to 15 kHz.
Intensity perception. VII. Further data on roving-level discrimination and the resolution and bias edge effects
Authors: Berliner J. E. , Durlach N. I. , Braida L. D.
Published: October 2005

This paper reports the results of further experiments on two-interval roving-level intensity discrimination and on the dependence of resolution and bias on level within the range of roving levels (the resolution and bias edge effects). The experimental parameters considered are the intensity range R, the intersignal duration T, and the pulse duration Tp. In order in obtain a picture of the natural bias, no feedback was presented. The results on the dependence of resolution on level are compared to previous results of the same type obtained from one-interval identification experiments. Discrepancies between the experimental results and the preliminary theory of intensity resolution [ Durlach and Braida, J. Acoust. Soc. Am. 46, 372–383, (1969)] are identified and implications of the data for an improved theory aree discussed.
Lateral position and interaural discrimination
Authors: Domnitz R. H. , Colburn H. S.
Published: October 2005

Experimental results are described for the dependence on interaural stimulus parameters of subjective lateral-position matches and just-noticeable differences (jnd’s) in interaural amplitude and time. All experiments employed 500-Hz tones presented through acoustically monitored headphones. The overall amplitudes of the stimuli were iteratively adjusted to eliminate subjective loudness cues in the interaural-amplitude jnd experiments. Performance in the experiments is analyzed within the framework of a probabilistic lateralization model in which internal noise is explicitly treated. The model predicts a specific relation between position matches and the interaural amplitude and time jnd’s. The data are qualitatively consistent with the predictions, and the quantitative agreement is good for one subject, moderate for the second, and poor for the third. In particular, the model predicts the observed asymmetry in the dependence of the interaural-time jnd on interaural time delay for nonunity interaural amplitude ratios. Calculated values of the internal noise of the subjective image position are in qualitative agreement with reports by observers of image diffuseness as a function of interaural parameters of the stimulus.
Acoustic integration for lateralization at high frequencies
Authors: McFadden Dennis , Moffitt C. Michael
Published: October 2005

Lateralization performance was measured as a function of signal duration using two-tone complexes of varying frequency separation, all centered at 3500 Hz. Acoustic integration occurs for this task, but the improvement with increasing duration is less rapid than would be expected were the subjects’ performance based on the number of opportunities available per trial to observe the value of the interaural time difference.
Acoustic coupling between two finite-sized spherical sources
Authors: Thompson William
Published: October 2005

The problem of acoustic radiation from a pair of spherical sources vibrating with time-harmonic velocity distributions which are constant in strength and axisymmetric about the same axis is considered. In particular, the modification of the radiation load on one source due to the presence of the other is evaluated. Numerical results are presented for the four cases of equisize sources which are either in phase or 180° out of phase from one another and vibrating in either the pulsating (monopole) or oscillating (dipole) modes. For sources which are small relative to the wavelength, the results are essentially as predicted by previous analyses of point sources, with the exception of the in-phase dipoles where, for small wavelength separations between the sources, the radiation resistance of one dipole is not doubled by the presence of the other. As the wavelength size of a source is increased, the near presence of another source affects the reactive component of the radiation loading more than the resistive component.
Properties of friction analyzers for [j]
Authors: Cole Ronald A. , Cooper William E.
Published: October 2005

Listeners were presented with stimuli from a nine syllable [?a]–[da] continuum (constructed using a natural speech [?a]) in which syllables differed in the duration of frication from 52 to 8 msec. In each experimental session, an initial identification test was conducted to determine the category boundary. This base-line test was followed by one of three adaptation tests in which subjects were presented with repeated syllables. The adapting stimuli consisted of (a) a single [?a] adaptor with 52 msec of frication, (b) a single [?a] adaptor with 32 msec of frication, (c) a ’’variable’’ adapting sequence that included the first six members of the test series and had a mean frication duration of 37 msec. The variable adapting sequence produced an adaptation effect equal in magnitude to the effect produced by the single adaptor with 32 msec of frication. The adapting syllable containing 52 msec of frication produced a significantly larger effect. The results demonstrate that (a) selective adaptation of speech did not require presentation of a constant adapting syllable and (b) the amount of adaptation depends upon the mean duration of frication contained in the adapting material at least up to 52 msec. A second experiment was performed to determine whether adaptation along a [?a]–[da] continuum was linearly dependent upon friction duration at values beyond 52 msec by comparing adaption produced by [?i], [?i], and [di] adaptors, containing friction duration of 120, 60, and 12 msec, respectively. The results showed that [?i] and [?i] produced highly similar adaptation effects on a [?a]–[da] series. The results suggest that an analyzer underlying perception of [?] is neither linearly nor symmetrically tuned to a particular range of friction duration.
Articulatory movements in VCV sequences
Authors: Gay Thomas
Published: October 2005

The purpose of this experiment was to study both the timing and positional properties of articulatory movements in VCV utterances. Conventional cinefluorographic techniques were used to track the movements of the upper lip, lower lip, jaw, tongue tip, and tongue body of two speakers who read randomized lists of VCV utterances containing the vowels /i,a,u/ and the consonants /p,t,k/, in all possible combinations. Results showed that the timing of articulatory movements in a VCV sequence are constrained by the intervocalic consonant, even if the gesture for the consonant is not a contradictory one. Anticipatory movements toward the second vowel always begin during the closure period of the intervocalic consonant. The appearance of carry over coarticulation effects depends on the phonetic identity of the particular segment or degree of involvement of the articulator. Carry over effects, like anticipatory effects, did not extend beyond an immediately adjacent segment. These findings suggest that the rules governing the segmental input to a speech string might be simpler than present models suggest.
Measurements of the acoustic radiation pressure on a sphere in a standing wave field
Authors: Rudnick Isadore
Published: October 2005

The force on a small sphere due to radiation pressure in a plane wave field was measured and was found to be in excellent quantitative agreement with L. V. King’s predictions [Proc. R. Soc. London Ser. A 147, 212 (1934)]. Reynolds numbers as high as 2500 were used.
New ultrasonic imaging system using a moving random phase mask and a stationary-point receiver
Authors: Sato Takuso , Wadaka Shusou , Ishii Junichi
Published: October 2005

A new ultrasonic imaging system and apparatus are proposed which use a moving random phase mask placed just behind a coherently illuminated object, and a stationary-point receiver located in the farfield. The power spectrum of the received signal represents the shadow of an object on the receiver plane and hence gives the image of the object under suitable conditions. The second-order correlation function of the received signal gives the exact image of the object provided a reference-point source is located nearby. The system constructed includes a minicomputer for signal processing and real-time imaging. Experimental results for one-dimensional objects are presented. It is also demonstrated experimentally that the system has advantages over conventional coherent ultrasonic imaging systems when propagating through a turbulent medium.
Model for the interaural time differences in the azimuthal plane
Authors: Kuhn George F.
Published: October 2005

An objective study of the steady-state interaural time difference (ITD) was performed on a manikin comprised of a head and torso. Data were taken for both a bare and clothed torso. The measured ITD’s correspond reasonably accurately at the low and the high frequencies to the computed theoretical values for a rigid sphere of an effective radius a. The theoretical ratio of the low-frequency (<500 Hz) ITD to the high-frequency (≳2000 Hz) ITD is 3/2. The measured ITD is a minimum between 1.4 and 1.6 kHz for angles of incidence, ϑinc, of sound between 15° and 60°. At both the low and the high frequencies the data can be expressed by universal curves when the ITD is normalized by (a/c0)  sinϑinc, where c0 is the speed of sound in air and ϑinc is the angle of incidence. Both the steady-state ITD and the interaural sound-pressure-level difference (ILD) show differences between measurements made with the bare torso and those with a clothed torso. These objectives results support the subjective measurements of past experiments, which showed that in man there was no localization improvement below approximately 500 Hz, poor localization between 1000 and 2000 Hz, and a change in the localization cue around 1400 Hz from ITD to ILD.
Temporal integration at the ’’threshold’’ of the acoustic reflex
Authors: Morgan Donald E. , Gilman Samuel , Dirks Donald D.
Published: October 2005

Investigation of the temporal integration of the acoustic reflex may be complicated by the operating characteristics of the instrumentation used to record the reflex. Several experiments were conducted to determine the operating characteristics of two impedance measuring systems (Madsen, model Z0−70 and Zwislocki Bridge (Grason Stadler, model 3), and to measure selected characteristics of the acoustic reflex, including (1) ’’threshold’’, (2) reflex intensity-growth functions, and (3) temporal integration functions at ’’threshold’’ for several stimulus frequencies. Results indicate (1) a smaller impedance change may be identified with a Madsen Z0−70 due primarily to the higher S/N (signal-to-noise) ratio in that instrument; (2) differences in temporal integration functions obtained between the two instruments were partially accounted for by differences in the operating characteristics of the two measuring systems; (3) the slope of the growth-intensity function decreases as signal duration decreases; and (4) the slope of the temporal integration function increases as the frequency of the eliciting stimulus increases.
Harmonic generation of longitudinal elastic waves
Authors: Thompson R. B. , Tiersten H. F.
Published: October 2005

The propagation of the fundamental and harmonically generated longitudinal elastic waves is treated by means of an asymptotic iterative procedure directly in the governing nonlinear differential equation. Explicit results are obtained for the steady-state, spatial growth of the second and third harmonic and the depletion of the input wave. As expected, the analysis indicates that the amplitude of the Nth harmonic depends on all the elastic constants up to order N+1. However, the forms for the amplitudes obtained in the asymptotic solution reveal that, for the known range of ratios of elastic constants of successively increasing order and propagation distances commonly encountered in harmonic generation experiments, only the quadratic nonlinearity, which depends on the second- and third-order elastic constants, is required to accurately account for the experimental results. In addition, the amplitude dependence of the phase velocity of the fundamental longitudinal wave is determined.
Backscattering spectra of preserved zooplankton
Authors: Greenlaw Charles F.
Published: October 2005

Measured backscattering spectra for preserved specimens of three zooplankters (copepod, euphausiid, sergestid shrimp) are compared to fluid sphere scattering models. Quantitative agreement is found at low ka for all species, however the copepod results are increasingly higher than predicted for ka≳1 and the euphausiid and sergestid shirmp are found to be directional scatterers. A fluid prolate spheroid model is proposed fo the latter species.
Comment on ’’Variability of low-frequency sound absorption in the ocean: pH dependence’’ [J. Acoust. Soc. Am. 61, 704–706 (1977)]
Authors: Lovett Jack R.
Published: October 2005

Published pH values, corrected to in situ conditions, improve the fit of the North-Pacific sound-absorption data with pH dependence.
Dynamics of a cylindrical shell system coupled by viscous fluid
Authors: Yeh T. T. , Chen S. S.
Published: October 2005

This study was motivated by the need to design the thermal shield in reactor internals and other system components to avoid detrimental flow-induced vibrations. The system component is modeled as two coaxial shells separated by a viscous fluid. In the analysis, Flügge’s shell equations of motion and linearized Navier–Stokes equation for viscous fluid are employed. First, a traveling-wave-type solution is taken for shells and fluid. Then, from the interface conditions between the shells and fluid, the solution for the fluid medium is expressed in terms of shell displacements. Finally, using the shell equations of motion gives the frequency equation, from which the natural frequency, mode shape, and modal damping ratio of coupled modes can be calculated. The analytical results show a fairly good qualitative agreement with the published experimental data. With the presented analysis and results, the frequency and damping characteristics can be analyzed and design parameters can be related to frequency and damping.