bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genesis of Endolymphatic Hypoxia Following Acoustic Trauma
Authors: Misrahy G. A. , Arnold J. E. , Mundie J. R. , Shinabarger E. W. , Garwood V. P. 
Published: September 2005

(1) Loud bursts of pure tone tend to decrease slightly the hydrogen diffusion rate into the first turn of the scala media of the eupneic guinea pig and markedly in the hyperventilated animal (2) White noise increases the rate of diffusion of hydrogen gas into the auditory cortex of the nonanesthetized cat. (3) Acoustic trauma produces vascular stasis in exposed blood vessels of the hamster cheek pouch.
These results are interpreted as indicating that the endolymphatic hypoxia following loud sound is due to a decrease in the oxygen supply/demand ratio resulting from (a) an increase in metabolism, and (b) no change, or decrease in cochlear blood flow and/or permeability of the stria vascularis.
Pulsation Oscillations of Cavities in Rubber
Authors: Meyer Erwin , Brendel Klaus , Tamm Konrad 
Published: September 2005

The oscillation behavior of a spherical cavity in an infinite elastic medium is calculated for the case of an incident spherical dilatational wave entirely reflected at the cavity walls. It is shown that there exists for every Poisson's constant 0⩽σ⩽0.5 a frequency for which the amplitude of the oscillating cavity walls becomes a maximum. It is also shown that the amplitude resonance curves are symmetrical and that, assuming loss-free material, they have a finite half-width, which is caused by radiation losses and depends only on the ratio of shear wave and dilatational wave velocity.
Pulsation oscillations of spherical, rotational-elliptical, cylindrical, and cubic cavities in rubber blocks were examined experimentally. The pulsation oscillations were excited by means of a sound source coupled to the surface of the rubber block. The sound pressure inside the cavities was measured with a probe microphone. The experimental results for spherical cavities are compared with the theory. Good agreement is found with respect to the resonance frequencies.
Vibrations of a System with a Finite or an Infinite Number of Resonances
Authors: Skudrzyk Eugen J. 
Published: September 2005

The study is based on the general differential equation of a mechanical system. Driving force and solution are expressed as a series of natural functions of the dissipationless system. Dissipation is taken into account by introducing complex elastic constants. Each Fourier coefficient of the driving force is written as the product of an excitation constant and the total driving force. The excitation constants can then be included in the mode parameters of the system and the solution, written as the product of the total driving force and the “mechanical impedance” of the system. The solution is exact and useful at the lower frequencies. A simple solution for higher frequencies can be derived by replacing the series by an integral and evaluating this integral. Three important parameters can thus be obtained: the driving-point impedance that describes the velocity of the driving point and the reaction of the system to the driving force, the effective impedance that represents the average velocity amplitude over the system, and the effective dissipation resistance with respect to this average-velocity amplitude.
The expression derived for the high-frequency driving-point impedance then turns out to represent, also, the general background level at lower frequencies. The solution for the driving-point impedance in the intermediate frequency range is obtained by adding to this background the contribution of the natural mode that has its resonant frequency closest to the frequency of the force; the effective impedance, on the other hand, is given with good approximation as the impedance of the mode whose resonance frequency is closest to the frequency of the force; and the effective dissipation resistance is given by the resistive component of this mode impedance.
The mode parameters are computed for rods, membranes, plates, and shells for three situations—a point force, a linear force distribution, and a force distribution given by a Fourier integral. The results make it possible to handle complicated mechanical systems with almost the same ease as simple mass points, and to compute their sound radiation.
Temporary Threshold Elevation Produced by Continuous and “Impulsive” Noises
Authors: Spieth Walter , Trittipoe William J. 
Published: September 2005

Three experiments compared the amounts of temporary threshold elevation resulting when a given total amount of noise energy was presented to the ear in the form of repeated, short, intense bursts, and in the form of continuous noise (of much lower maximum intensity). Several patterns of noise bursts were tested, as well as continuous noise. One-millisecond noise bursts and continuous noise, of 20 min duration, were tested most extensively. The most severe impulsive noise tested consisted of 1-msec bursts every 10 msec for 20 min, with a burst SPL of 127 db or long-time-average level of 117 db.
It appeared quite conclusively that 1-msec bursts of noise have considerably less effect than the equivalent amount of continuous energy on thresholds at 3000, 4000, 6000, and 8000 cps. Noise bursts of 10 msec, 100 msec, and 1 sec length were tested less extensively; it appears that they would cause no more threshold elevation than would the equivalent amount of continuous noise.
Noise Origin, Power, and Spectra of Ducted Centrifugal Fans
Authors: Howes F. S. , Real R. R. 
Published: September 2005

Forward and backward curved blade centrifugal fans as noise sources were subjected to an extensive study, measurements being made in a duct with an acoustic termination. The data obtained support the following conclusions:
(1) The noise output from each homologous series of fans can be defined by one V-shaped specific noise power vs log specific speed curve, with minimum close to maximum static efficiency.
(2) Fan outlet noise power at maximum fan efficiency approximates 10−5 times the input fan power.
(3) The noise origin is primarily blade and air flow boundary turbulence.
Automatic Recognition of Phonetic Patterns in Speech
Authors: Dudley Homer , Balashek S. 
Published: September 2005

The mechanical recognition of ten spoken words (the digits) with near-perfect precision has been demonstrated under laboratory conditions for a single talker after optimum circuit adjustment for his voice. Such word recognition points to the possibility of automatic voice writing and other voice-controlled operations.
The device described is based on two principles—the recognition of sustainable patterns of power versus frequency in speech, and the recognition of the durations of such phonetic patterns in words.
An alphabet of only ten patterns is proven adequate for limited word recognition, at least in the case of a single talker. The successful performance of the ten-word digit recognizer for voice dialing of telephone numbers was recorded on a motion picture film shown in the oral presentation. Data from the film are discussed in this paper.
This paper describes a working model of a phonetic pattern recognizer built at Bell Telephone Laboratories based on a detailed power-frequency spectrum analysis. Tests, to be discussed, indicate that this device, which supersedes an earlier model, leads to almost perfect digit recognition when set for a particular voice. The device also offers outstanding possibilities in speech transmission. The former application will be described in this paper and the latter in a companion paper.
Attenuation and Dispersion of Sound by Solid Particles Suspended in a Gas
Authors: Zink Jay William , Delsasso L. P. 
Published: September 2005

Observations were made on audio-frequency sounds propagating through a gaseous medium containing small solid particles in suspension. Two effects were observed, the attenuation and the dispersion. The measurements were carried out by sending short trains of sine waves through the particle-filled gas and observing the changes in the transmitted train of waves after the particles settled out of the gas. The variation in arrival time of the pulse was used to determine the velocity change caused by the suspended particles. Changes in the amplitude of the received pulse made it possible to determine the additional attenuation due to the suspended particles.
The variations of the attenuation and velocity with frequency due to the particle-filled gas were obtained and the results compared with theory. The measured attenuation was found in good agreement with existing theory. The observed dispersion satisfactorally accounted for by a theory that is introduced in this paper. The attenuation theory takes into account enhanced viscous and thermal losses caused by the suspended particles. The dispersion theory predicts the velocity shift resulting from changes of the heat capacity and density of the gas containing the suspended particles,
Effect of Noise on an “Intellectual” Task
Authors: Broadbent D. E. 
Published: September 2005

Three groups of Naval Ratings worked for two sessions each at a subtraction task involving a considerable immediate memory load. One group had both sessions in relative quiet (70 db), a second had the first session in 100 db noise and the second in quiet, and the third group had noise and quiet in the reverse order.
In the first session the noise group slowed down at solving the subtractions as time went on, relative to the groups working in quiet. A similar difference appeared in the second session, but, in addition, there was an aftereffect of noise such that the subjects who had had noise previously slowed down relative to those who had not.
Slowing down of performance with time was in all groups most marked in extroverts.
These results suggest firstly that intellectual work as well as simple sensory tasks must be regarded as endangered by noise. Secondly, there may be harmful aftereffects from noise, but it is not clear whether these will appear in any situation or only in one similar to that in which the noise was experienced.
Absorption of Sound in Oxygen Containing Hydrogen, Carbon Dioxide, or Water Vapor as Impurity
Authors: Harlow R. George , Nolan M. E. 
Published: September 2005

Measurements of the attenuation of sound are reported for oxygen containing up to 2.6% of hydrogen, carbon dioxide or water vapour as impurity. The measurements cover the f/p range from 80 to 1700 Hz/atm and were made with a resonance tube system. The least-squares fits to the results are given below, where 103h is the mole fraction of the impurity, and f0 is the frequency of maximum absorption.
Mixture Equation Standard error
O 2 - H 2  f0/p=−0.3+64.2h Hz/atm 9 Hz/atm
O 2 - CO 2  f0/p=9+ 45h Hz/atm 70 Hz/atm
O 2 - H 2 O  f0/p=9+162h+144h2 Hz/atm 26 Hz/atm
The results are compared with those of other workers, and in particular, it is suggested that the results of Harlow and Kitching are probably in error because they ignored the adsorption of water vapor on the walls of the tube.
Incidence and Prevention of Damage Due to Mechanical Shock
Authors: Parfitt G. G. , Snowdon J. C. 
Published: September 2005

In order to evaluate the performance of shock mountings in a simple manner, it is very desirable to express by a single quantity the liability to damage of the contents of fragile equipment. The conditions on shock duration under which the acceleration, displacement, or velocity associated with the input transient may be employed to describe the liability to damage in place of the full shock spectrum are therefore discussed.
In shock-mounted equipment it often appears desirable to avoid mechanical elements that, by virtue of their low resonant frequencies, are sensitive to changes in displacement or velocity. If this is possible, acceleration remains as the factor of chief concern, and a mount must be chosen to provide an acceptable compromise between the resulting reduction in acceleration and the introduction of relative motion. Characteristic curves facilitating this choice are proposed, and the influence of mount nonlinearity and damping on the curves is briefly discussed.
Pure-Tone Loudness Relations
Authors: Lochner J. P. A. , Burger J. F. 
Published: September 2005

A knowledge of pure tone loudness relations is of fundamental interest to all workers in the field of human hearing. Of these relations the pure tone equal-loudness contours, three sets of which have been independently established, are probably the best known. These three sets of contours have the same general shape but show considerable deviations over parts of the auditory diagram.
Making use of the results obtained by different workers and assuming a recently established loudness-stimulus relation to hold at all frequencies in the audio range, a new set of equal loudness contours has been calculated. A set of curves giving the loudness of equal stimulus contours has also been calculated.
Determination of the Parameters of a Piezoelectric Transducer from the Decay of Resonant Vibrations
Authors: Redwood M. 
Published: September 2005

The usual method of determining the RLC parameters of the equivalent circuit of a transducer involves the measurement of admittance or impedance over a range of frequencies near resonance. An alternative method is described here. The transducer is first excited in mechanical resonance by applying an electrical signal; the excitation is then removed and the electrical signal produced by the transducer as the mechanical vibrations decay is observed by using an oscilloscope. Under certain conditions the parameters of the transducer equivalent circuit may be determined rapidly from measurements of the initial amplitude of the electrical signal and the rate at which it decays.
The theory of the method is described and used to determine its limitations; the method is particularly suited to rapid measurements on transducers of reasonably low coupling coefficient (less than about 0.4) and reasonably large Q (100 or more). A simple experimental system suitable for measurements to an accuracy of ±10% is discussed and investigations on a barium titanate transducer resonating in a bar mode are described in some detail; the parameters obtained using the decay method compare favorably with those obtained using the conventional admittance method.
Contributions to a Theory of Separability of the Vector Wave Equation of Elasticity for Inhomogeneous Media
Authors: Hook Joseph F. 
Published: September 2005

In a recent paper, the author introduced a generalization of the Helmholtz theorem for representation of vectors in terms of potential functions. It was shown that use of this generalization leads to separation (in the dependent variables) of the vector wave equation of elasticity for certain inhomogeneous media whose properties are functions of the Cartesian coordinate s. The conditions for separability are a system of nonlinear differential equations for the constitutive parameters. Only a few special solutions of this system were given. An almost complete catalog of the separable cases is developed in the present paper.
The vector differential properties of the field for the separable cases are discussed. It is shown that the P and S fields are irrotational and solenoidal, respectively, provided we regard as the fundamental field vectors the quantities f1uP, f2uSV, and uSH rather than the displacement vectors themselves, where f1 and f2 are appropriate weighting functions. The vector differential properties of the displacement vectors themselves are derived and these results compared with similar results obtained by the eikonal method of analysis.
Problem of Sound Scattered by Sound
Authors: Lauvstad V. , Tjøtta S. 
Published: September 2005

The sound generated by the nonlinear interaction of two sound beams of high intensity, arranged to cross each other perpendicularly, is computed to the first order of interaction. Several of the assumptions and specializations in previous treatments of this problem, whose effects on the result it is hard to estimate, are avoided. The interaction is supposed to take place in the Fraunhofer zone of both beams.
Some results obtained are of general validity. For instance, the Doppler angles computed and measured by Ingard and Pridmore-Brown are found, without any strict specializations of the primary beams and the interaction region.
Estimates of the amplitudes of the generated pressure, governing rather wide ranges of frequencies of the primary beams, seem to agree with the previous apparently strongly differing results. This correspondence is brought forward by an amplitude factor, depending on the frequencies of the primary beams.
In the high-frequency limit, the destructive interference among the quadrupoles which give rise to the generated sound dominates the results and gives an over-all zero value of the generated pressure, in accordance with Westervelt's treatment.
Structural Fatigue under Combined Random and Swept Sinusoidal Vibration
Authors: Spence H. R. , Luhrs H. N. 
Published: September 2005

Combined random and swept sinusoidal vibration is used in the qualification of missile electronic equipment. The subject of this report is how structural fatigue produced by a combined excitation is related to structural fatigue produced by another combined excitation or to that produced by individually applied random or sinusoidal excitation. In particular, a method is given by which different random or combined random and sinusoidal vibration excitations can be compared. This method finds practical application in comparing vibration specifications and tests, and for the purpose of modifying vibration requirements from one type to another.
In this derivation, substitute sinusoidal vibration excitations and sweep rates are based on the response characteristics of a single resonator system, while amplitude and time relationships are based on the S-N diagram of the material under consideration. Equations and curves are given and their use illustrated by means of a numerical example.
Fractional and Multiple Judgments of Loudness
Authors: Ham Lloyd B. , Biggs Frank , Cathey Everett H. 
Published: September 2005

Data on loudness estimates at 60, 200, 500, 1000, 5000, and 10 000 cps were continued at the University of Arkansas from 1933 to 1959. A recalculation of all data to 1950 indicated that fractional judgments required a smaller decibel change of intensity than the corresponding multiple loudness estimates. This new result, hereafter referred to as the directional dependency, accompanied by a provisional explanation, was recorded in the Journal of the Arkansas Academy of Sciences in 1950, and reported together with certain additional experiments at the Second ICA Congress in June of 1956.
Since reluctance to accept unanticipated results is considerable, a new approach to a series of experiments designed to explore this directional dependency was preceded by review of a possible dynamical explanation. The follow-up experiments included the proposed dynamical explanation as a part of the experimental objective and included new methods in our laboratory for the recording of judgments.
The results of the earlier series have been confirmed, but a satisfying explanation has not been established.
Compressional Bone Conduction in Cochlear Models
Authors: Tonndorf Juergen 
Published: September 2005

Animal experiments have suggested the possibility that the compressional mode of bone conduction might produce a displacement of the cochlear partition, even when the cochlear windows and all other potential pressure outlets are closed. This assumption was found correct for the case of a cochlear model. It executed so-called “distortional” vibrations, i.e., while its walls in one place moved inward, those in the other moved outward and vice versa. This mode of motion tends to keep constant the total volume of the enclosed incompressible fluids.
The two perilymphatic spaces are known to differ in volume. Distortional motion causes the volume difference to alternate, thus producing compensatory displacements of the partition. This is in contrast to the effect upon the partition of the translatory and antiphasic movements of the cochlear windows in response to air-conducted sound. When both windows are open, or only one is occluded, the displacement of the partition, due to bone-conducted sound, represents the combined result of distortional and translatory motion.
The generation of traveling waves, when input and output are distributed over the entire cochlear shell, as in bone conduction, is discussed in terms of general cochlear mechanics.
High-Frequency Extensional Vibrations of Sandwich Plates
Authors: Chu Hugh N. 
Published: September 2005

In this paper there is derived a set of approximate equations governing the extensional motion of a sandwich plate, together with the associated initial and boundary conditions. Both the sandwich core and the facings are assumed homogeneous and isotropic, and the facings are assumed thin and identical to each other. The coupling effect of the thickness deformation of the core is considered in the derivation.
Frequency-wavelength curves are then obtained from these equations for an infinite plate in plane strain. The corresponding curves for the same plate according to the three-dimensional exact theory of elasticity are also obtained. These two sets of curves are then used as a basis for discussion of the accuracy of the approximate equations.
The curves indicate that for commonly used core materials and for wavelengths about three times the plate thickness and longer, the approximate equations are reasonably good up to frequencies somewhat higher than the fundamental thickness-stretch frequency of the plate.
Neural Mechanism of the Peripheral and Central Auditory System in Monkeys
Authors: Katsuki Y. , Suga N. , Kanno Y. 
Published: September 2005

The cochlear nerve of the monkey is composed only of the axons of the primary neurons. In Part I of this article, the properties of the primary auditory neuron—i.e., tonotopic organization, response pattern, and response area—have been studied. Two groups of neurons could be stochastically separated in terms of threshold in the low- and middle-frequency range and not in the high-frequency range. The rate of increase of impulse frequency with the change of sound intensity was examined at the characteristic frequency (CF) of a neuron after the measurement of its response area. The rate of increase and the threshold of a neuron were found to be well-correlated. This result seems to show the validity of Békésy's hypothesis on the pitch-intensity coordinate system of the inner and outer hair cells.
Part II is concerned with the responses of the cortical neurons of unanesthetized monkeys. Two types of response areas, wide as well as narrow, were obtained with single-tone bursts. By the simultaneous delivery of two sounds, these areas were found to be altered in different ways, even though they were originally similar. The response patterns for beat sounds also were different from neuron to neuron. The cortical neurons are characterized by the phasic on, off, and on-off response patterns. Intracellular recording of the membrane potentials of neurons revealed that a brief depolarization was often found before or after a long hyperpolarization by a sound stimulation. Owing to such types of responses, very many cortical neurons may be able to discriminate such complex sounds as musical sounds or voices which are always changing. The spatial and temporal funneling action in the neural mechanism of hearing is discussed.