bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Broad-Band Masking Noise on Consonant Confusions
Authors: Wang M. D. , Bilger R. C. , Jesteadt W. H.
Published: October 2005

Perceptual confusions were obtained at six speech-to-noise ratios ranging from −10 to +15 dB, at over-all noise levels of 50, 65, 80, and 95 dB SPL. Stimuli were four sets of CV and VC nonsense syllables formed by combining all English consonants with the vowels /i,a,u/. Noise levels of 80 and 95 dB resulted in poorer discrimination, particularly at moderate speech-to-noise ratios. Performance also varied as a function of vowel, syllables with /u/ being consistently better discriminated than others. An iterative feature analysis of transmitted information revealed that in both the Miller and Nicely [J. Acoust. Soc. Amer. 27, 338–352 (1955)] and Chomsky and Halle [Sound Pattern of English (Harper & Row, New York, 1968)] feature systems, voicing accounted for the greatest relative transmitted information. [Research supported by a grant from SRS].
Focusing of an N Wave by a Spherical Mirror
Authors: Corset E. P. , Blackstock D. T.
Published: October 2005

An experimental and theoretical study of N-wave focusing has been carried out. An N-wave source (electric spark) was located on the principal axis of a spherical mirror so as to produce a focus (image point) beyond the center of curvature. The signals before, at, and beyond the focus were received by a wide-band condenser microphone of our own manufacture. Linear theory in the form of the Kirchhoff integral was used to obtain predicted waveforms. Corrections for known nonlinear propagation effects were applied. The data is explained adequately by the composite theory. Diffraction from the mirror's edge plays a prominent role. Before the focus, the reflected signal, a normal N wave, is followed in time by the diffracted signal, which is an inverted N. As the focus is approached, the amplitude becomes large and the delay between the two signals tends to zero, giving rise to a U-shaped wave, which approximates the derivative of the original N. Thus the well-known π/2 phase shift at the focus is explained as the superposition of the two signals. Beyond the focus, the phase shift of both signals is π; in addition, the order of arrival is reversed. Nonlinear effects cause distortion of the reflected signal, particularly after the focus, where the initial shape is an inverted N. [Work supported by ONR and AFOSR].
Propagation of a Weak Oblique Shock through a fusing Gas Mixture
Authors: Sanai Mohsen , Toong Tau-Yi , Pierce Allan D. , Salant Richard F.
Published: October 2005

The propagation of a weak oblique shock, such as that generated by a supersonic projectile, through a two-component diffusing gas mixture, has been investigated analytically. A linearized ray analysis has disclosed that a two-branched caustic, with associated arête, is formed. The arête and caustic positions have been found as functions of diffusion time, initial Mach number, and molecular weight ratio.
Neural Correlates of Habituation of the Cardiac Component of the Orienting Response
Authors: Sanwald Judith C. , Bliss David K.
Published: October 2005

Amplitudes of multiple unit activity (MUA) responses to an auditory stimulus decrease with stimulus repetition. Correlations between neural response decrements and the time course of other indices of habituation [e.g., orienting response (OR) habituation] are not known. We explored the relationship between habituation of the cardiac OR and response changes in the lateral midbrain reticular formation (LMRF), inferior colliculus (IC), and medial geniculate (MG) over successive stimulus presentations. Intracranial electrodes and subcutaneous EKG electrodes were chronically implanted in 16 rats. Subsequently, they were curarized and respirated in a chamber equipped with an overhead speaker. At mean intervals of 90 sec, a 5-sec tone was presented. Twenty successive presentations were made at each of two frequencies. Cardiac rates during the five successive tone seconds were compared with rates for five successive pretone seconds. Most rats showed initial deceleratory responses, which habituated. Others gave acceleratory responses, which were also decremental over trials. The response-generated MUA was analyzed for changes in spike frequency. Amplitudes of MLRF responses either decreased over the 20 trials or showed an initial increment, then a decrement. Smaller decrements occurred in MG responses and occasionally we saw an initial sensitization. IC responses also tended to decrease over trials. [Supported by a grant from SUNY Research Foundation.]
Stimulus Sequencing and the Late Components of the Auditory Evoked Potential
Authors: Beckham J. B.
Published: October 2005

Amplitude of the late components of the averaged auditory evoked potential increases as the time between repeated stimuli is increased up to 12 sec. The interspersal of tone bursts of different frequencies within the interstimulus time interval was investigated as a method for improving data acquisition rate without sacrificing response amplitude. Series of 500-, 1000-, and 2000-Hz tone bursts were presented singly and in combinations of two and three frequencies at repetition periods of 1 to 8 sec. Response records were sorted and averaged according-to stimulus frequency, yielding one, two, or three averaged evoked potential records. Experimental results indicate that data acquisition rate can be improved by serial presentation of different stimuli without significant loss of response amplitude. [This project was made possible through funds granted by the University of Southern Mississippi Faculty Research Council.]
Can Explosion Sources Give an Apparent Transmission Gain
Authors: Christian Ermine A.
Published: October 2005

The total pressure wave generated by an underwater explosion gradually changes in shape as it propagates out to long ranges. As a result of different attenuation rates in various segments of the high-amplitude explosion pressure wave, the waveform begins to approach a damped sinusoid at some distance from the charge. The effect of varying waveforms on spectral energy distributions has been studied theoretically, with the explosion pressure-time pulse modeled by the function p(t) = C exp(−αt) cosβt. Values of C, α, and β were derived from empirical functions of explosive charge weight and depth, and range. This analysis shows that the changing waveform may serve to sustain spectrum levels for frequencies in the neighborhood of the explosion's bubble pulse fundamental frequency. Consequently, when the theoretical values for a given charge configuration are combined in the customary sonar equation format, the expected transmission loss can become an apparent transmission gain for selected frequencies. These theoretical results raise the interesting question of whether some of the variability in reported attenuation coefficients might be attributable to the particular explosion sources used in the measurements. [This work sponsored by the Office of Naval Research.]
Underwater Parametric Reception in the Case of a Spherically Spreading Pump and a Plane-Wave Signal
Authors: Shooter J. A. , Berktay H. O. , Willette J. G. , Truchard J. J. , Barnard G. R.
Published: October 2005

Parametric reception is an economical means of generating a large virtual continuous end-fire array to gain directivity in the detection of low-frequency signals. In this paper, we assume a spherically radiating pump that mixes with a plane-wave low-frequency signal to generate a secondary sound field at the sum and the difference frequencies. A closed-form solution for the radiated secondary sound field is presented and compared with an “exact” numerical solution. Both theoretical methods are shown to be in good agreement with one another and an experiment performed in a fresh water lake. The experiment consisted of a pump mounted on one end of a 50-ft 1 beam projecting a 90-kHz narrow beam to a receiving hydrophone on the opposite end of the 1 beam. The signal was a 5-kHz fixed source located 150 ft from the center of the 1 beam. The receiving system was tuned to (90±5) kHz and as the 1 beam was rotated, beam patterns were generated that agree well with the theoretical results. [This work was sponsored by the Office of Naval Research.]
Vertical Larynx Height during Vocal Frequency Change
Authors: Shipp T. , Haller R. M.
Published: October 2005

Vertical larynx height was filmed and thyrohyoid muscle activity sampled in two subjects during continuous and discrete-interval vocal frequency change. For continuous frequency change (glissando), the results showed a high positive relationship between larynx height and vocal fundamental frequency (r=0.93) within the modal register, a moderate relationship within the falsetto register (r=0.42), and no relationship within the pulse register (r=0.01). Discrete-interval frequency change showed a similar pattern of larynx height as in continuous change, with the absolute position of the larynx height as in continuous change, with the absolute position of the larynx in the two conditions ±5 mm at matching frequency points. Thyrohyoid muscle activity level was always found to be directly related to vertical larnyx position.
Thyrometer—A Method for Observing Laryngeal Control in Speech
Authors: Kakita Yuki , Hiki Shizuo
Published: October 2005

This paper reports on the “thyrometer,” an optoelectric device for observing the laryngeal control in speech through the movement of the thyroid cartilage. Upward and downward movement of the thyroid cartilage tilts the mirror put on the skin surface near the process of the thyroid cartilage of speaker, and swings the light beam reflected by the mirror. The swinging angle is converted into the variation of light intensity through a specially designed optical mask; then the transmitted light beam is focused on the photocell to obtain the voltage monotonically related to the movement. This method allows a highly sensitive recording of the vertical movement of the thyroid (or cricoid) cartilage in speech almost free from the obstruction of utterance with the simpler device. As the time variation of the movement (“thyrogram”) corresponds well with the pitch frequency contour in the speech sample in which the change in pitch frequency is considered to be attributed mostly to the laryngeal control, the thyrogram is assumed to show the laryngeal control that underlies the change in pitch frequency. Result of the observation is utilized to estimate the contribution of laryngeal control separately from that of expiratory control in speech, and the nature of the laryngeal control for suprasegmental features is discussed in terms of a physiological model of glottal sound production.
Vibration and Buckling of Anisotropic Shallow Shells
Authors: Oyler J. F. , Dym C. L.
Published: October 2005

The free vibration frequencies and the critical buckling loads of certain thinwalled shells of revolution constructed of anisotropic materials—layered or heterogeneous—are studied, the specific geometries being circular cylinders, barrels of positive and negative Gaussian curvature, and spherical sections. The buckling configurations include axial compression and simple radial pressure. In each case the shell boundary conditions are simple supports. The analyses are based upon shallow shell theory, linearized about an initial membrane pressurization state. Using known modal techniques, a frequency determinant is derived. From this determinant studies of the effects of in-plane inertia, of various wave numbers, and of the physical parameters of the shell are carried out. Additionally, results for the static buckling of these shells under axial compression and radial pressure are also obtained, using the kinetic buckling criterion. Parameters studied in the vibration and stability analyses include the thickness-to-radius ratio, initial pressurization, circumferential and axial wave numbers, and the degree of anisotropic asymmetry. The latter effect is studied by the comparison of analyses of two different layered anisotropic materials—each constructed of five equa thickness orthotropic layers with varying orientations. The orientations have been selected to produce varieties of anisotropy—midplane symmetric and midplane asymmetric. The results of these free vibration and stability analyses have produced the following conclusions: (1) the effect of anisotropic asymmetry is so significant that it must be considered; (2) the increased stiffening found for orthotropic cylinders as a consequence of increased thickness ratio and initial pressurization also was found for the general anisotropic family of shells studied.
Vibration of Statically Deformed Beams and Plates
Authors: Davies Huw G. , al Sowayel Saud
Published: October 2005

The response of beams and plates to fluctuating loads with high mean values is considered. The static deformation is obtained separately: the vibration of the statically deformed structure is then discussed in terms of the induced static in-plane (membrane) stresses. It is shown that the response of a deformed plate can be predicted by defining an effective uniform tension. Simple expressions are obtained for the loss factor in terms of the impedance of the supports of the beam or plate. Expressions are given for the changes due to the tension of modal resonance frequencies and loss factors (assuming constant boundary impedance). The predicted changes in loss factors agree quite well with some previously published experimental data for very thin plates. The changes for most cases of practical interest, however, are small.
The Direct and Reverberant Response of Strings and Membranes to Convecting, Random Pressure Fields
Authors: Leehey P. , Davies H. G.
Published: October 2005

The vibratory response of strings and membranes to convecting random pressure fields is discussed, with particular attention being paid to the traveling wave component of the response. A closed-form Green's function describes the string response. The pressure field is modeled by a summation of random sinusoidal excitations: such a sum, suitably defined, has been shown to represent an ergodic process in a limiting sense. The response of a finite string is shown to divide naturally into a direct response characterized by the convection velocity and decay rate of the pressure field, and a reverberant response characterized by the wave velocity and damping of the string and which exhibits modal resonances. The analysis is extended to include membranes by expanding the lateral membrane response in a modal summation. Each lateral mode is treated analagously to the string. It is shown approximately for small damping that the longitudinal space-time response cross correlation has a reverberant component symmetric about zero time delay and a direct component symmetric about the convection time (spatial separation/convection velocity). These symmetry properties are used to obtain values of the convection velocity from experimental measurements.
Effective Modal Density in a Reverberant Sound Field for Finite Sized Sources
Authors: Sharp Ben H. , Eldred Kenneth M.
Published: October 2005

Much of the theory concerning the formation of sound fields in reverberant rooms and the measurement of the sound levels produced by these fields has emphasized the statistical aspects. A previous paper [K. M. Eldred, B. H. Sharp, and F. M. Murray, “The Coupling of Finite Sized Sources to a Modal Reverberant Sound Field,” presented at the 76th Meeting of the Acoustical Society of America (Nov. 1968), J. Acoust. Soc. Amer. 45, 338 (A) (1969)] discussed the coupling of finite sized sources to a reverberant sound field and showed that there is a strong dependence between sound level and source configuration in certain frequency ranges. This paper will briefly review these findings and extend the work to examine the relationship between the effective modal density and the calculated modal density as a function of source configuration. On the basis of this relationship, the relevance of statistical methods as applied to reverberant sound fields with finite sized sources will be discussed.
TTS Accompanied by Sustained Reduction of AP Amplitudes in Noise-Exposed Guinea Pigs
Authors: Maioriello Richard P. , Wilpizeski Chester
Published: October 2005

Guinea pigs were fitted with permanent recording macroelectrodes having tips located in the auditory-nerve-cochlear-nucleus region. After recording detection levels and input-output functions for clicks or pure-tone bursts under waking conditions using computer-averaging techniques, the animals were exposed to 115 dB SPL of broad-band noise for 1 h. Postnoise measurements were made within the hour following exposure and for at least four weeks thereafter. VDLs shifted for clicks and midfrequency tonal stimuli, although corresponding suprathreshold AP responses showed sustained reduction of peak-to-peak amplitudes. The altered form of the AP input-output functions is characteristic of nerve fiber depopulation conditions and suggests that damage occurred to the ear in spite of the fact that VDLs returned to prenoise levels.
A Normative Study of Listening-Rate Preferences of Adults
Authors: Lass Norman J. , Cain Cheryl J.
Published: October 2005

A paired comparison procedure was employed to determine the listening-rate preferences of 100 adult subjects. The recording of a standard prose passage was time altered by means of a speech compressor to yield nine reading rates: 100, 125, 150, 175, 200, 225, 250, 275, and 300 wpm. A total of four master tapes were constructed, one for each of the four different orders employed for presentation of the readings. Each tape consisted of 36 pairs [n(n−1)/2], with each of the nine reading rates appearing eight times on the tape. Each of the four master tapes was played to a different group of 25 subjects for their listening-rate preference evaluations. Results of their evaluations indicate that (1) all but one of the nine rank orders of preferred listening rates were identical for all four subject groups; and (2) the most preferred listening rate for all groups was 175 wpm, and the least preferred rate was 100 wpm. Implications of these findings for future research are discussed.
Macrosonics and the Ultrasonic Motor
Authors: Balamuth L.
Published: October 2005

Macrosonics is presented as a part of a complete periodic motion and mechanical vibration spectrum, followed by a resume of the uses of ultrasonic motors, including the category of macrosonic motors that covers a frequency range dipping down into the sonic and subsonic levels. Several features of ultrasonic motor design, to which the author has contributed, are presented and are connected with practical problems that arise in applying such motors in the macrosonic sense. These features include the production of high output motor velocities without benefit of effects normally associated with ultrasonic horns or mechanical impedance transformers; the incorporation into a macrosonic motor of a “flywheel” effect; and the provision of macrosonic energy storage by means of motor elements whose cross section is not limited by the usual quarter wavelength requirements. The elementary properties of macrosonic motors are reviewed together with the relevance of such properties to macrosonic technological applications. Specifically, some of these properties are illustrated in greater detail in reference to joining metals and plastics, as well as to metal deformation. The special areas selected are confined to methods and means arising directly out of the author's work.
Fusion of Plastic Powders with Macrosonics
Authors: Fairbanks H. V.
Published: October 2005

Both thermosetting and thermoplastic powders were molded into 12-in. diam cylinders by the application of macrosonics plus a nominal constant pressure without the use of external heat. A series of factorically designed experiments were run using ultrasonic intensity, pressure, and time as the variables. The measured length of the fused cylinder of plastic formed in each experiment was used to evaluate the response. All the variables were found to be relatively important to the fusion process. However, only the interaction of time and pressure was found to be important. This interaction had a negative slope coefficient.
Parameterless Intensity Formula from the Eikonal Function
Authors: Wood D. H. , Lesick Andrew A.
Published: October 2005

Let r and z denote cylindrical coordinates and let sound speed be a function c(z) of z alone. Let r = 0 and z = z0 be the coordinates of a point harmonic source. If we can find a solution t(r,z,z0) of the eikonal equation (∇t)2=c−2, then the ray acoustics approximation to the intensity of the sound field can be expressed as 10 log10|cc0trtrr(1−c2tr2)−12(1−c02tr2)−12/r|, where tr and trr are partial derivatives of t with respect to r and c0 is c(z0). Notice that the above expression for intensity is an explicit function of r and z without any ray parameters. The level curves of t are, of course, wavefronts. Differentiating the eikonal equation with respect to r shows that the level curves of tr are rays because they are everywhere orthogonal to the wavefronts. Rays, wavefronts, and intensities are found for three examples, c = coshz, c = 1 + z, and c = ez, by the above results and explicit formulas for t(r,z,z0) such as cost = (cosr+sinhz sinhz0)/(coshz coshz0), when c = coshz, an unpublished result of G. S. Egeland.
Statistics of Distant Shipping Noise
Authors: Dyer I. , O'Connor J. C.
Published: October 2005

In an earlier paper by Dyer, a rudimentary analytical model was proposed for distant shipping noise in the ocean. This model has been extended to reflect actual ocean conditions better. With this extension, the dependence of statistical parameters on the disposition of ships at sea and on the observational beamwidth and bandwidth may be more readily understood. Predictions of the newer model compare favorably with measurements and are believed to be valid in the frequency range within which the noise of distant shipping dominates wind-generated sea surface noise or noise of other mechanisms. The dependence on depth and the temporal correlation of the noise envelope are not explicitly considered in the model, but will be discussed.
Sound Propagation in Horns
Authors: Mawardi O. K.
Published: October 2005

A generalized theory is developed for the theory of propagation of sound waves in horns of semiinfinite length. A few approximate treatments are described to derive in closed form the acoustic impedance of horns. Some specific examples will be given for horns whose contour is described by analytic functions.
Noise Measurement Standards for Machines in situ
Authors: Lang William W.
Published: October 2005

Two classes of documents prescribe standards for noise measurements on machines and stationary equipment in the field. Fundamental methods of measurement are described in documents prepared by American National Standards Committee S1 for which the Acoustical Society of America serves as the Secretariat and by Technical Committee 43 of the International Organization for Standardization (ISO). Test codes applicable to specific types of equipment are prepared in the United States by engineering societies and trade associations. These two classes of documents should be mutually supportive and interdependent, but such is not always the case. The requirements of existing standards on noise measurements in situ are summarized, the shortcomings of these documents are described, and the needs for new standards are reviewed. An estimate is given of the degree to which current standardization activities are satisfying these needs.
Response of the Primary Auditory Neuron to Human Speech
Authors: Goldstein Allan J. , Mundie J. Ryland
Published: October 2005

A previous report [81st Meeting Acoust. Soc. Amer., J. Acoust. Soc. Amer. 50, 83(A) (1971)] documented that pulse occurrence histograms from primary auditory neurons of guinea pigs followed the time history of the bidirectional displacement patterns of the basilar membrane predicted by an electronic “analog cochlea” model. The basilar membrane describes a surface when stimulated by an auditory signal. This surface represents the point by point displacement of the basilar membrane along its length as a function of time. This paper presents data from many neurons distributed (on the basis of characteristic frequency) along the length of the basilar membrane. The data demonstrate that the temporal and spatial details of the complex surfaces of human speech sounds are preserved in the pulse occurrence histograms up to the temporal resolving power of our computer system (200 μsec). At low stimulus intensity, only those features that correspond to large displacements are seen in the pulse occurrence histogram; as stimulus intensity is progressively increased, features corresponding to smaller amplitude displacements progressively appear. There is not a linear relationship between magnitude of displacement and magnitude of neural response. Although the data collected to date have been analyzed on the basis of displacement patterns, we are unable to exclude velocity of the basilar membrane as the input to the primary neuron.
Estimation of the Integration Time-Constant in Auditory Receptor Units
Authors: Kletsky E. J. , Stengrevics J. M.
Published: October 2005

Period histograms obtained from eight-nerve units of monkey by Brugge et al. [J. Neurophysiol. 32, 386 (1969)] show a high correlation with positive-going excursions of the stimulus waveform. A more detailed examination reveals that the histograms decay more slowly than the stimulus, suggesting a temporal integration in the receptor unit. We have estimated the value of the time constant to be between 0.1 and 0.2 msec by matching eighth-nerve period histograms with those generated by means of an analog model of the auditory receptor and first-order neuron. These values are consistent with the maximum frequency at which substantial time locking is observed physiologically. The model assumes the following sequence of events. Linear amplitude summation of stimulus and intrinsic noise is followed by half-wave rectification and integration with a time constant of about 0.15 msec. The resulting signal, a receptor potential, controls the average rate at which packets of transmitter substance are released to form EPSP in the first-order neuron. The times of packet release are assumed to be random and follow a Poisson distribution. An electronic implementation of the model was constructed and used with a previously developed neuron model to generate data for these studies.
Detection of Sinusoids in Noise as a Function of the Signal-to-Noise Ratio on Individual Trials
Authors: Kaplan Howard
Published: October 2005

Current models of the auditory detection of a sinusoid in a noise background propose that the probability that a subject will claim to detect the sinusold on a particular trial increases with the total energy present in a critical frequency band on that trial. This leads to the counter-intuitive prediction that, among a set of true signal-with-noise trials in a single run in which a subject is working with a fixed criterion, it is those trials with the most noise background on which the subject is most likely to detect the signal. An alternative theory is that the subject discriminates signal trials from noise-alone trials on the basis of the contrast, or energy difference, between the largest single component in a band of frequencies and the mean energy of the components. This theory predicts that those trials with the least noise added to a signal are those on which the subject is most likely to detect the signal. Experiments designed to compare these two theories have yielded data consistent with the predictions of the second, or energy contrast, theory.
Cochlear Potentials of the Pigeon: Relationships to Age, Serum Cholesterol Level, and Atherosclerosis
Authors: McCormick James G. , Clayton Robert M. , Holleman Ivan L.
Published: October 2005

The cochlear potentials of different breeds of pigeons were measured. Potentials of old pigeons that developed spontaneous carotid atherosclerotic plaques were generally 15–18 dB poorer in sensitivity than younger birds of the same breed with little or no evidence of plaques. In another breed of pigeon, resistant to spontaneous atherosclerosis, but susceptible to high-cholesterol-diet-induced coronary atherosclerosis, differences in potentials were less clearly defined; however, both the older birds and younger diet treated birds tended to be less sensitive than young nondiet treated birds.
Effect of Potassium Deficiency on Cochlear Potentials and Cation Content in Endolymph
Authors: Konishi T. , Kelsey E.
Published: October 2005

The scala vestibuli and/or scala tympani in guinea pigs were perfused with K+-free modified Ringer's solution. Cochlear microphonics (CM), summating potential (SP), action potential (AP), and endocochlear potential (EP) were recorded from the basal turn of the cochlea before, during, and after the perfusion. Perfusion of both scala vestibuli and tympani with the normal Ringer's did not result in appreciable changes in the cochlear potentials or Na and K content in the endolymph. Perfusion of the perilymphatic space with K+-free Ringer's caused significant suppression of EP and AP. The CM was also reduced in magnitude and accompanied by increase of the positive SP. These changes were reversible by washing with normal Ringer's. The measurement of K and Na content in the endolymph indicated that the K deficiency in the perilymph brought about significant increase of Na content and decrease of K content. The role of K ions in the perilymph for the generation of EP is discussed. [Work supported by a Public Health Service grant].
Rule Synthesis of Simple English Sentences
Authors: Olive J. P.
Published: October 2005

Simple English sentences were generated by concatenating words spoken in isolation with minimum modifications of the synthesis parameters. The sentence forms were: Article-(adjective)-subject-verb-article-(adjective)-object. The two adjectives may or may not be present. A dictionary of 266 words specified by formant data with the duration of the words adjusted by linear interpolation to a reasonable duration for connected speech was stored. Pitch rules for the different sentences were derived from an average sentence pitch contour. Words were concatenated with no further duration adjustment, and formant smoothing was applied only at voiced adjacencies for one set of data of both the preceding and the following words; the pitch, however, was replaced by the rule pitch. The rule-generated sentences were compared with sentences obtained from formant analysis-synthesis of naturally spoken sentences, rather than with the naturally spoken sentences themselves, because formant analysis-synthesis introduces a characteristic nonnatural quality that is not a consequence of the rule-prosody. These comparisons demonstrated that the quality of the rule concatenated sentences is comparable to the quality of the resynthesized speech.
Viola with Electronically Simulated Body Resonances
Authors: Gorrill W. S.
Published: October 2005

A viola, somewhat similar to Mathews' violin, has been built with electronic simulation of the body normal modes. Since subjective evaluation of the tone by musicians in actual performance is one of the major objectives, the appearance and apparent sound source location have been kept as close as possible to those of a normal instrument. A battery power supply is used. The effect of broad-band versus narrow-band filters for the higher frequency regions has been investigated. The instrument is rather easier to play than a normal 15-in. viola, but provides depth and power of tone more comparable to a 17-in. instrument. The viola will be demonstrated.
Acoustics as a Human Science
Authors: Stevens S. S.
Published: October 2005

There was a time when acoustics was only a human science, but this changed as philosophers learned to use mathematical and other measurement tools for ordering and validating their thought processes. This century has seen many changes in the description of the field as a whole, and the human aspects continue to be among the most perplexing. The highlights of accomplishments to date, some observations on our current status of knowledge, and some projections into the future are presented for your entertainment—if not for your information.
Bubble Dynamics
Authors: Plesset Milton S.
Published: October 2005

Recent work on vapor cavities and gas-filled bubbles will be discussed.
Dynamics and Oscillation of Nonspherical Bubbles
Authors: Hsieh D. Y.
Published: October 2005

A brief survey is first given on the linear stability analyses of the motion of spherical bubbles. These include the stability of the growth and collapse of bubbles in an incompressible liquid and the stability of bubbles in oscillation. The linear stability formulations are extended to include the effect of the compressibility of the liquid and the effect of heat and mass transfer across the bubble wall. Then a variational method is formulated to deal with the case when the nonsphericity of the bubble is not small. This method leads to some new approaches for approximate treatments of dynamics and oscillations of nonspherical bubbles. Some examples are treated and numerical results obtained.
Laser-Induced Cavitation
Authors: Lauterborn W.
Published: October 2005

When intense laser light is focused into liquids, bubbles can be prod need in the vicinity of the focal point. The dynamics of these bubbles is investigated by high-speed photography with picture repetition rates up to 106 frames/sec. Single spherical bubbles can be produced. In water, they can be said to be the experimental realization of the Rayleigh bubble model. Results on both spherical and nonspherical bubble collapse, rebound, and subsequent collapses and rebounds will be reported showing the sequence of events leading to the cloud of minute bubbles often observed after the collapse of a big bubble. Repeated jet formation of the same bubble seems to be the major suicide mechanism. Shedding of minute bubbles occurs by gas entrainment into the jet. Spherical undisturbed collapsing bubbles remain spherical down to very small radii being heavily distorted a few microseconds later during rebound. Nonlinear spherical bubble oscillations are investigated in silicone oils. The stability of the spherical shape seems to be enhanced by viscosity. A comparison is made with calculated nonlinear bubble oscillations damped by viscosity.
Effect of Surface Tension on the Cavitation Threshold of Water
Authors: Crum L. A. , Gallemore J. B. , Nordling D. A.
Published: October 2005

The threshold for transient cavitation in degassed water has been measured in a stationary wave system as a function of surface tension. A surfactant was used to vary the surface tension of water from approximately 70 to 30 dyn/cm2. The cavitation threshold was found to vary inversely with the surface tension in disagreement with the theoretical predictions of Apfel [J. Acoust. Soc. Amer. 48, 1179–1186 (1970)]. Glass capillary tubes were used to construct macroscopic models of microscopic crevices thought to nucleate cavitation. The crevices were coated with polystyrene in order to obtain a nonwettable surface. Measurements made of the receding contact angle of an air-water interface moving in the model crevice showed a critical dependence of the contact angle upon surface tension. Motion pictures will be shown of the receding contact angle as a function of surface tension and how this receding interface may nucleate cavitation. If an empirical relationship is made between the contact angle and the surface tension, and this empirical dependence used in Apfel's theory, then good agreement is obtained between theory and experiment. [Work supported by the Office of Naval Research and the Naval Academy Research Council.]
Studies of Periodic and Transient Deformations by the Method of Double-Pulsed Holographic Interferometry
Authors: Shajenko Peter
Published: October 2005

Studies of deformation of mechanical structures subjected to periodic and transient excitations have been made by the method of double-pulsed holographic interferometry. A Q-switched ruby laser with pulse duration of 20 nsec and coherence length in excess of 1 m was employed. To demonstrate vibration analysis, a thin steel plate was driven over a range of frequencies and amplitudes. The amplitude in order of 0.1 mm was recorded; 288 fringes in a thin plate are clearly readable. Shock waves were recorded in a thick plate, transducer housing, and a solid rod. In a thick plate, an amplitude of 220 fringes was obtained. In loud-speaker studies, the various effects such as paper stiffness of the cone, cone asymmetry, etc., on the frequency response can be deduced from the extremely fine details in the mode structure. The loudspeaker was driven to provide the power output level up to 95 dB at a number of frequencies and the details of characteristic mode structure are presented. The technique described is characterized by the high dynamic range and the extremely high fringe contrast attainable; the technique is relatively insensitive to spurious vibrations. As a result it is applicable to testing under diverse operational conditions.
Response of a System Consisting of N Coupled Elements
Authors: Tucker A. J. , Maidanik G.
Published: October 2005

The impulse response function method, which was developed previously by Tucker and Maidanik [J. Acoust. Soc. Amer. 51, 87(A) (1972)] is extended to a system containing N-coupled elements where the coupling acts only at a point of each element. The essence of the method is that it considers the coupling to be a force field acting on an uncoupled element of the system. Then this coupling force field together with the external driving field and the impulse response functions of the uncoupled elements determines the response of the coupled system to an arbitrary external driving field. This method does not require a priori definition of the exact nature of the individual elements; it requires only the existence of the elemental impulse response function and knowledge of the type of coupling. As a specific example, the general result is utilized to investigate a system where the elements are identical, the coupling impedances are identical, the points of attachment on each element are similar, and a point driving force is applied to only one element. Then the effect on the response of the system of various degrees of coupling and the number of elements in the system is examined.
Acoustic Backscattering from Spherical and Cylindrical Shells
Authors: Brill Donald , Überall H. , Uginčius Peter
Published: October 2005

The target strength of thin spherical and cylindrical elastic shells, either air- or water-filled, has been calculated in order to assess the effects of penetrability of the shell material on the scattering process. Calculations have been performed using both the Kirchhoff method and the Watson-Sommerfeld transformation of the Rayleigh normal-mode series. The contribution of specular reflection from the vertex can be separated out in either method, and distinguished from shadow-boundary reflections or creeping-wave contributions. Similarly as in the normal-mode calculations of Diercks and Hickling [J. Acoust. Soc. Amer. 41, 380 (1967)], the penetrability effects were found to be considerable.
Experimental Measurements of the Scattering of Acoustic Waves by Rough Surfaces
Authors: Welton P. J. , Frey H. G. , Moore P. G.
Published: October 2005

Measured scattering coefficients are presented for four randomly rough, pressure-release surfaces that are statistically related. The scattering data were collected at frequencies of 100, 200, and 500 kHz for forward, specular, and backscattering geometries. The ratios of acoustic wavelength to surface rms height (λ/h) range from 6.5 to 0.33. The wide range of scattering geometries, frequencies, and roughness included in these measurements make these data the most complete collection of acoustical scattering measurements yet available for statistically known rough surfaces.
Regulation of Vehicular Noise in Hawaii
Authors: Burgess J. C.
Published: October 2005

A detailed Public Health Regulation entitled, “Vehicular Noise Control For Oahu,” is awaiting signature by the Governor. The regulation applies to all vehicles and their auxiliary devices when operated on traffic-ways on the Island of Oahu. Separate objective standards are specified for “light” and “heavy” vehicles. Motorcycles are included with the light vehicles. For all vehicles, operational noise limits are specified in terms of sound level A, posted speed limit, and measurement distances between 20 and 50 ft. For heavy vehicles, times of day and days of the week are also specified. Goals for the future are identified. An important feature of the regulation is the definition of an extensive permit system. Its function is to allow stringent standards to be set initially while providing for administrative flexibility to grant exceptions necessary in the public interest. Other important sections of the regulation concern exemptions, truck routes, mufflers, measurement, enforcement, and publication.
Automatic Control of Transformer Noise by Synthesizing Directivity
Authors: Kido Ken'iti
Published: October 2005

The noise of outdoor transformers has been controlled chiefly by acoustic screen, but the effect of the screen has not been so large. On the other hand, some efforts to make a transformer with low noise level have been carried out and the radiated noise level from newly designed low noise transformer has been largely decreased by the vibration insulation between the core and the outer case. But the cost of the transformer has increased. The idea of controlling the noise with some additional sound sources had been proposed as an acceptable method, which is adopted in this paper. The sound field around the transformer must be controlled by the adjustment of the amplitudes and the phases of the additional sound sources. But how to adjust them is so difficult that there have not yet been practical results. The proper adjustment of the additional sound sources is difficult because the conditions of the sound field and the power source may change at times. Therefore, it is necessary to control automatically the amplitudes and the phases of the additional sound sources. The author has developed the practical method of automatic control of the noise and proved the effectiveness of the controlling method. The outline of the fundamental considerations and the successful results of the field experiments are described in this paper with the explanation of directivity synthesis, problems of stability, and the controlling procedure, especially the successive adjustment method.
Analysis of Noise Generation in Industrial Wood Planers
Authors: Stewart John S. , Hart F. D.
Published: October 2005

The primary sources of noise from industrial wood planers are associated with board radiation and aerodynamic phenomena. The factors that control board radiation have been studied analytically and experimentally. The parameters considered include board width, length, thickness, and wood species. A model for determining the sound power emitted because of board radiation is developed, and theoretical results are compared with experimental data. Board width is shown to be the most important board geometric parameter in noise radiation. [NASA and Newman Machine Company are acknowledged for partial sponsorship of this work.]
Amelioration of Deafness
Authors: Martin Edwin W. , Niemoeller Arthur F. , Stevens Kenneth N.
Published: October 2005

Although medical advances will help prevent deafness and engineering developments may provide auxiliary resources, the primary responsibility for ameliorating this handicapping condition, particularly for children, rests on education. Available evidence suggests that the age of beginning educational intervention, including auditory amplification, language and speech development, and parent guidance, is extremely important—the earlier the better. Early education also requires procedures for identification of deafness. Some States have now legislated programs for children younger than five years, but much more remains to be accomplished.
Acoustical Properties of Alaryngeal Speech
Authors: Weinberg B.
Published: October 2005

This paper will review recent findings coming from a research program in which the acoustic properties of various types of alaryngeal speech were examined. The fundamental frequency, rate, phonation time, long-term spectral, and vowel-formant frequency characteristics of male and female esophageal talkers were measured in an attempt to provide information about the physical properties of esophageal speech and to find correlates to listeners' judgments of the sex of these speakers' voices. Significant sex differences were found for some of the physical measures. These studies show that close relationships can be found between the acoustical and perceptual spaces of esophageal voices. In other experiments, the acoustical properties of two other types of alaryngeal speech—buccal and pharyngeal speech—were measured in an attempt to evaluate their potential use as primary methods of alaryngeal speech. Studies of the mechanism of phonation, fundamental frequency, phonation time, rate, intelligibility, and long-time spectral characteristics of buccal and pharyngeal speech were completed. The results of these experiments support the hypothesis that both buccal and pharyngeal speech do not represent efficient or practical primary methods of alaryngeal speech.
Crash Survivability
Authors: Warner Charles Y.
Published: October 2005

The starting point for automotive crash-worthiness design must be the tolerance of the human biological system to impact. For obvious reasons, human tolerance to impact cannot be evaluated by a simple test of ultimate strength. The human body has an infinite number of degrees of freedom, and many modes of loading which pose threats of injury. Further, no samples of actual material are available for destructive testing. Present design information on human tolerance is a composite of extrapolations from accidental impacts, human experiments at voluntary levels, cadaver experiments, and animal exposures at injury and fatal levels. Although a large body of experimental data has been accumulated, it must be carefully interpreted if valid design decisions are to be reached. Anthropometric dummies enter into the design process at two levels. First, dummies can contribute to knowledge of occupant crash dynamics, at least up to the instant of second collision. (The contribution thereafter is greatly dependent upon the degree of sophistication of the dummy.) Second, the dummy may be used to evaluate the performance of a given design. Of course, results of any testing with dummies depend upon the realism of dummy performance for the specific hardware and the mode of impact being investigated. This presentation outlines one program for determining automobile crash survivability criteria. Human tolerance is estimated by volunteer and animal tests of several restraint systems. The interaction of the vehicle structure, restraint system, and occupant are demonstrated by the results of prototype vehicle crash tests.