bluuebunny/crossref_metadata_2025_split huggingface dataset:
Speech recognition through spectrogram matching
Authors: Ingemann Frances , Mermelstein Paul 
Published: October 2005

In order to assess human analysis of acoustic data before attempting such analysis by machine, a series of experiments was conducted in which subjects were asked to match spectrograms of continuous speech to reference spectrograms of the same words. Although error rates varied with sentence difficulty and size of vocabulary, comparison of the matches shows greater agreement in phoneme segments than other experimenters have obtained in phonetic transcriptions of unknown utterances without semantic of syntactic processing. Accuracy in matching can be further improved by feedback to the human analyst in the form of spectrographic representation of a sequence of tentative matches spoken as if they made up the unknown utterance. The results suggest that automatic matching of word− or syllable−sized acoustic patterns may provide a more accurate phonemic input to the syntactic−semantic component of a speech recognition system than direct transcription of individual phonetic segments.
Subject Classification: 70.65, 70.60.
Sampled−data representation of a nonuniform lossless tube of continuously variable length
Authors: Strube H. W. 
Published: October 2005

The sound transmission through a nonuniform tube (e.g., the human vocal tract) is digitally simulated using a tube consisting of uniform segments, the length of which is determined by the sampling frequency. Then the problem arises of how continuous changes of the tube length can be represented. It is solved by inserting a segment of variable length, which causes fractional powers of z to appear in the z−transform expressions describing the transmission behavior. These are made rational by first− and third−order expansion in (z−1 − 1). For a uniform tube, the resulting error in formant bandwidth is calculated.
Subject Classification: 70.50.
Matrix formulation of acoustic scattering from multilayered scatterers
Authors: Peterson Bo , Ström Staffan 
Published: October 2005

A T−matrix formulation of both acoustic and electromagnetic scattering has been given by Waterman for the case of one homogeneous scatterer, and this formulation has subsequently been extended to the case of several such scatterers by the present authors. In the present article we show that the matrix formulation is also well suited for the treatment of acoustic scattering from scatterers consisting of an arbitrary number of consecutively enclosing homogeneous layers with different propagation constants. We also show how the earlier results on the matrix formulation of acoustic scattering can be combined with these new results so as to apply to more general types of multilayered scatterers. Some numerical applications are given.
Subject Classification: 20.30.
Measurements of radiation impedance
Authors: Gilheany John J. , McCumber Leonard , Andrews Frank A. 
Published: October 2005

A method is described for measuring the free−field radiation impedance of a single−degree−of−freedom underwater transducer. The displacement amplitude and phase of the vibrating surface in air and in water are measured with a laser interferometer and with an accelerometer. From these values and the input current, the radiation impedance may be computed. Measurements of the radiation resistance and reactance of a J9 transducer at 0.5−kHz intervals from 5.0 and 10.0 kHz are reported. The radiation resistance is also calculated from reciprocity calibrations and measurements of the directivity patterns at 5.0, 7.5, and 10.0 kHz. Excellent agreement is observed between the two methods.
Subject Classification: 30.50.
Unified analysis of conical ray transmissions with application to a time−varying ocean channel
Authors: Widtfeldt J. A. , Jacobson M. J. 
Published: October 2005

A unified treatment of conical ray paths, corresponding to a nonlinear sound−speed profile family, is presented. For a concave downward profile, ray arcs may be hyperbolic, and there may be two such paths. They may also be parabolic or elliptic, with vertical major axis. For a concave upward profile, ray arcs are elliptic with horizontal major axes. When a CW sound source and receiving point lie on a horizontal bottom, the number of bottom reflections, initial ray angle, travel time, and spreading loss are studied in detail for RBR (refracted/bottom−reflected) rays. In an application of our results, temperature data off the Miami coast is used to determine sound−speed profile variations as a function of time. The acoustic phase of the total RBR field is then computed at a receiver 3 NM from the source. Theoretical phase variations are shown to be in reasonably good agreement with experimental phase fluctuations.
Subject Classification: 30.20, 30.25.
Transverse vibration of constrained rods with axial force fields
Authors: Kunukkasseril V. X. , Arumugam M. 
Published: October 2005

Free transverse vibrations of rods which are axially constrained at ends and initially loaded with an axial force at an intermediate point are discussed. The theoretical developments are based on Timoshenko equations and explicit solutions and results have been obtained for hinged−hinged and fixed−fixed beams. Various interesting and new aspects, such as the influence of the magnitude and location of axial forces on the frequency spectrum, are evident from the numerical results.
Subject Classification: 40.22.
Normalized curve of molecular absorption versus humidity
Authors: Harris Cyril M. 
Published: October 2005

Numerical values are given here for the normalized curve of molecular absorption versus humidity, a relationship obtained in an earlier study of sound absorption [J. Acoust. Soc. Am. 40, 148−159 (1966)]. These data, heretofore unpublished, form important input information in setting up a computer program for the evaluation of air attenuation.
Subject Classification: 35.20; 55.30; 28.40.
Difference thresholds for interaural delay
Authors: Hafter E. R. , De Maio J. 
Published: October 2005

Cross−correlational models of binaural interaction postulate an interaural delay line in which neural impulses arising in one ear are delayed relative to those from the other. For localization based on interaural differences of time, accuracy is limited by the resolving power of this hypothetical delay line. The present study sought to determine whether the delay line is organized in such a way as to provide a foveal area of best acuity, as exists in spatial vision. Thus, threshold increments of interaural time difference (Δt)’s were determined as a function of overall delay (t). Stimuli were acoustic transients of either low (0.1 to 2 kHz) or high (3−4 kHz) frequency content, ranging in level from 18 to 68 dB SPL. The overall delay ranged from 0 to 500 μsec. In general, the functions that relate Δt to t were found to rise gradually with lowest thresholds occurring for the lower−frequency and higher−level clicks. In exception were the results from weak high−frequency clicks, which showed a marked and sudden rise at large values of t. Ignoring the sudden rises in these latter cases, the resolution of the delay line is best described by a shallow decay in acuity over the range of delay tested, and though accuracy is best in the center, clearly no sharp delineation exists in sound localization as in vision.
Subject Classification: 65.62, 65.75.
Relation of the loudness function to the intensity characteristic of the ear
Authors: Hellman W. S. , Hellman Rhona P. 
Published: October 2005

A representation of the pure−tone loudness function given by Ψ = xϑF (x), where x is the ratio of stimulus to threshold intensity, is discussed. The form of F (x) is obtained from the empirical loudness curves at 1000 and 250 Hz. The structure of F (x) is shown to be in quantitative agreement with known steady−state driven firing rate activity of eighth−nerve units. We suggest that F (x) is proportional to the driven firing rate function RD(x) of the auditory sensory receptor. A specific choice is made for the algebraic form of RD(x) by identifying it with the driven rate function in a sensory receptor model proposed recently by Zwislocki. Within the model, a three−parameter fit to the loudness function is obtained. It is shown that similar results can be obtained for vibrotaction.
Subject Classification: 65.35, 65.50.
Systematic error in some methods of reverse correlation
Authors: Wilson J. P. , Evans E. F. 
Published: October 2005

Two methods of triggered correlation using an averager were tested on several types of filter network. Under certain conditions systematic differences were found between the reverse correlograms and the directly measured impulse responses of the filters. The basis of this error would appear to be that threshold events are not always sampled randomly in these methods.
Subject Classification: 65.20, 65.35.
Forced vibration of the damped bilinear hysteretic oscillator
Authors: Masri S. F. 
Published: October 2005

An exact solution is presented for the steady−state motion of a sinusoidally excited single−degree−of−freedom system exhibiting bilinear hysteresis and subjected to viscous damping that may be different in the ’’elastic’’ region from the ’’yielded’’ region.
Subject Classification: 40.20.
Elastic waves in free plates
Authors: Vrba J. , Haering R. R. 
Published: October 2005

We have investigated the dispersion curves of free waves in free plates. We have shown that for certain conditions a simple exact solution is possible, since incident shear (SV) waves are decoupled from the transmitted longitudinal (P) wave (and vice versa). The concept of phase decoupling yields a useful description for the construction of approximate dispersion curves in terms of certain decoupled modes M1−M4. The validity of various approximations based on these modes is discussed. The fomulation may be readily extended to anisotropic and to active plates.
Subject Classification: 40.24.
Directivity of truck noise in the normal plane
Authors: Commins Daniel E. 
Published: October 2005

Measurements have been performed of the sound pressure levels of highway noise sources, including trucks, with an array of microphones in the plane perpendicular to the direction of motion. The results show that highway sources exhibit quasi−omnidirectionality, when described in terms of A−weighted levels, at angles up to 45° above the horizontal independently of the type of vehicle or of the type of exhaust. For trucks there is limited evidence of a weak distortion of the directivity pattern of the radiated noise which increases with the number of wheels at high speed. One−third−octave−band spectral analysis at angles between 6° and 45° from the horizontal do not reveal a significant variation in the spectrum from one angle to another. For the purpose of highway noise prediction, it appears reasonable to assume that the noise radiated from conventional vehicles, including trucks, is omnidirectional.
Subject Classification: 50.50, 50.25.
Prediction of transmission loss in mufflers by the finite−element method
Authors: Young Cheng−I James , Crocker Malcolm J. 
Published: October 2005

A numerical technique based on the finite−element method has been developed for analyzing the performance of systems of acoustic elements including expansion chambers in mufflers. The theories developed are, firstly, the variational formulation of the acoustic field existing in the system and, secondly, the finite−element approximate solutions of the variational problems. The predictions of transmission loss are then made by forming the equivalent acoustic four−terminal transmission network in which the acoustic four−pole constants are calculated from the finite−element method. As used, the finite−element approach is perfectly general and may be applied to any system component with arbitrary boundary geometry provided this may be realized by an assembly of rectangular elements. The method is applied to simple expansion chamber models because the results are tractable and theoretical results from acoustic filter theory are available for comparison purposes. The comparison brings out an important fact: the accuracy of the prediction of transmission loss implies that the variational formulation and finite−element approximations are adequately applicable to a number of practical applications.
Subject Classification: 50.40; 20.40.
Nonlinear internal waves in the atmosphere
Authors: Cho H. R. , Liu C. H. , Yeh K. C. 
Published: October 2005

Nonlinear dispersive effects on the propagation of atmospheric internal waves are investigated. The finite amplitude buoyancy oscillation is analyzed to obtain an amplitude−dependent oscillation frequency. A nonlinear dispersion relation for finite−amplitude internal waves is derived. Its relation to the nonlinear buoyancy oscillation is discussed. The nonlinesr dispersion relation is then used to study the stability of finite−amplitude modulated internal wave trains. It is found that, for certain modulations, wave trains propagating in certain directions may become unstable.
Subject Classification: 28.20.
Effect of voiced speech parameters on the intelligibility of PB words
Authors: Agrawal Arun , Lin Wen C. 
Published: October 2005

The voiced/unvoiced regions of PB words are segmented on the basis of the energy in time segments. It is shown that the energy parameter works quite well and better than zero crossings rate (ZCR) for this segmentation. The real poles and formants of the voiced speech production model are obtained by solving a polynomial whose coefficients are determined by Prony’s or covariance formulation of linear prediction. The effect of these poles and formants on the intelligibility is investigated by using zero filters to suppress them adaptively. With this approach, one or more formants or real poles are removed from the natural speech without affecting anything else. The processed words were presented to listeners using an on−line speech intelligibility measurement system. The results indicated that the suppression of real poles and third and fourth formants did not degrade intelligibility, while the suppression of first and second formants lowered the average intelligibility scores by 7.6% and 27.6%, respectively.
Subject Classification: 70.30.
Measurement of the glottal waveform
Authors: Sondhi Man Mohan 
Published: October 2005

The glottal volume flow is usually estimated by inverse−filtering the speech wave, by taking a motion picture of the vocal−cord vibration, or by a variety of other methods that estimate the size of the glottal opening. We present a much simpler alternative based on the following idea: The effect of the vocal−tract resonances on the glottal pulse is considerably reduced by speaking into a reflectionless uniform tube. If, in addition, the tract is held in a neutral position, the effect is almost entirely eliminated and the glottal waveform may be recorded by a microphone in the uniform tube. Some examples are presented of glottal pulses recorded in this manner. The new method is compared to the ones available heretofore, and some potential uses of the method are suggested.
Subject Classification: 70.60.
Mach bands in auditory masking revisited
Authors: Small Arnold M. 
Published: October 2005

Further data are provided in an attempt to replicate the Carterette, Friedman, and Lovell [J. Acoust. Soc. Am. 45, 986−998 (1969)] report of lateral inhibitions in the auditory system. These data show no evidence of this effect.
Subject Classification: 65.58. 65.75.
Quadrature sampling error formula
Authors: Persons C. E. 
Published: October 2005

It is known that the Grace−Pitt interpolation formula [O. D. Grace and S. P. tt, ’’Quadrature Sampling of High Frequency Waveforms,’’ J. Acoust. Soc. Am. 44, 1453−1454 (L) (1968)] allows an exact reconstruction of a high−frequency bandlimited waveform when the sampling rate is an integer submultiple of the center frequency. The problem addressed here is the determination of the ratio of the power in the error bands to the power in the signal band when the formula is used for any sampling frequency.
Subject Classification: 60.XX.
Mechanism for aural pulse compression in mammals
Authors: Altes R. A. 
Published: October 2005

The pulse compression phenomenon is examined in terms of nonlinear phase functions in the frequency domain. The concepts of neural inhibition and critical bandwidth filtering are then employed to show that a logarithmic spectral phase function can be easily synthesized in the mammalian auditory system. Pulse compression of linear period−modulated signals, such as those used by some bats, can therefore be simply implemented at a peripheral level of the aural processor.
Subject Classification: 65.35, 65.42.
Binaural pinna disparity: another auditory localization cue
Authors: Searle C. L. , Braida L. D. , Cuddy D. R. , Davis M. F. 
Published: October 2005

Physical measurements of the transfer function from a free−field sound source to a microphone in the subject’s ear canal indicate that there are two independent localization cues generated by the pinna. For sound sources in the vertical median plane, there is a systematic change in the frequency response as a function of elevation angle, and a disparity between the left−ear and right−ear responses which also changes systematically with elevation angle. Independent psychophysical measurements indicate that these pinna cues are detectable by subjects, and both are used by subjects in vertical localization tasks.
Subject Classification: 65.62, 65.75.
Excitation of surface elastic waves in a piezoelectric layered structure
Authors: Ponamgi S. R. , Tuan Hang−Sheng 
Published: October 2005

The excitation of Rayleigh surface waves by an interdigital transducer (IDT) on a piezoelectric layered structure has been studied in this paper. The surface wave velocity, optimum finger width, and number of fingers for maximum bandwidth for the IDT have been calculated for several values of the product (ks) of wavenumber and layer thickness. The frequency response and equivalent circuit of the IDT have been determined. Numerical examples are also presented and discussed.
Subject Classification: 20.15.
Vibration and wave propagation in ribbed plates
Authors: Rumerman M. L. 
Published: October 2005

A formalism for handling problems of wave propagation and forced vibration in ribbed plates is presented. A general solution is obtained for the forced vibration of an infinite thin plate, periodically stiffened by identical, uniform ribs. The ribs are idealized as parallel line attachments capable of exerting line forces and line moments upon the plate, and the magnitudes of these forces and moments are related to the motion of the plate through the impedances of the ribs and plate. The assumption of an externally applied pressure excitation, which varies harmonically in time and in the plane of the plate, permits an explicit solution, and the principle of superposition is then used to construct the solution to an arbitrary excitation. By setting the amplitude of the harmonic excitation equal to zero, an equation for the free modes of the ribbed plate is derived.
Subject Classification: 20.15.
Time and frequency analyses of auditory signal detection
Authors: Ahumada Al , Marken Richard , Sandusky Arthur 
Published: October 2005

Observers rated 500−msec bursts of wide−band Gaussian noise for presence or absence of a 100−msec, 500−Hz signal tone. The tone was present on half of the 400 trials and was centered in the noise bursts. Bandwidth and integration time estimates were found for each observer by correlating the observer ratings with the output of energy detectors of various bandwidths (20, 40, 100, 250 Hz) and integration times (50, 100, 300, 500 msec) to find the best correlating energy detector. The results, computed separately for signal (SN) and no signal (N) trials, indicate a bandwidth of 40 Hz and an integration time of 100 or 300 msec fit best on both SN and N trials. Energy variations in 25 50−Hz by 100−msec segments of the noise were correlated with the observer ratings and showed negative correlations in frequency and time intervals immediately surrounding the signal region on SN trials, but not on N trials. The results suggest observer monitor detectors sensitive to temporal and spectral changes in the energy of the noise bursts, not just the absolute level of the output of a simple filter−integrator energy detector. The N trial results are accounted for by assuming that the observer is looking for the same pattern of temporal and spectral changes as on SN trials, but is uncertain as to the exact location of the signal tone.
Subject Classification: 65.58, 65.35.
Influence of middle−ear muscle contraction on pure−tone suprathreshold loudness judgments
Authors: Morgan Donald E. , Dirks Donald D. 
Published: October 2005

Some effects of middle−ear muscle (MEM) contraction on TTS and suprathreshold loudness judgments have been assessed in three experiments. Experiment I was designed to demonstrate the effect of MEM contraction on TTS while in Experiments II and III the influence of MEM contraction on the loudness of suprathreshold pure−tone stimuli was measured. In Experiment I, MEM contraction decreased the effective level of a high−intensity TTS−inducing stimulus reaching the cochlea. In Experiments II and III signal paradigms were chosen to reduce or eliminate the effects of binaural loudness summation, and contralateral remote and backward masking effects, and to maximize the influence of MEM contraction. Results of the loudness judgments indicated no effect of binaural interaction, whereas the MEM contraction affected the loudness of pure tones only when the stimuli were low frequencye (250, 500 Hz) and high intensity (≳100 dB SPL). The results further imply that at high intensity levels there was an interaction between the effects of the intensity of the loudness−judgment stimulus and the intensity of the reflex−inducing stimulus. That is, when the reflex was induced the effect on loudness increased as the intensity of the loudness−judgment stimulus was raised; likewise, when the loudness−judgment stimulus was maintained at a constant sound−pressure level but the intensity of the reflex−inducing stimulus was increased, the effect on loudness increased.
Subject Classification: 65.50, 65.22, 65.24.
Reaction time procedure for measurement of hearing. II. Threshold functions
Authors: Pfingst Bryan E. , Hienz Robert , Miller Josef 
Published: October 2005

The reaction−time (RT) procedure applied to the measurement of suprathreshold functions in the preceding paper may also be used to measure threshold. This paper examines threshold contours measured by the RT procedure in human and monkey subjects with normal and impaired hearing. In the human subjects, thresholds obtained using the RT procedure closely paralleled those obtained in the clinic but were an average of 2.7 dB lower; RT thresholds were an average of 5 dB above thresholds obtained in a forced−choice procedure. Thresholds obtained from monkey subjects paralleled the normal human contours within the human frequency range of hearing, but were slightly higher at frequencies below 4 kHz and lower at frequencies above 4 kHz. The monkeys’ hearing extended approximately 11/4 octave above the humans’. Thresholds measured using the RT procedure in human and monkey subjects agreed well with thresholds previously reported in the literature. The effects of sound presentation and calibration procedures on the shape and position of the threshold contours are examined in an appendix.
Subject Classification: 65.50, 65.64, 65.75; 85.24.