bluuebunny/crossref_metadata_2025 huggingface dataset:
Damping of first sound and viscosity of liquid He-B3 near superfluid transition
Authors: Kojima H. , Kodama T.
Published: October 2005

The viscosity of normal fluid component of the isotropic B phase of liquid He3 in the vicinity of the superfluid transition temperature was measured from the damping of 22-kHz first sound in a cylindrical resonator. In the normal fluid region, the viscosity, η, varies like T−2 as expected, where T is temperature. In the superfluid phase, just below the transition temperature Tc, η decreases very rapidly. The reduced viscosity η (T)/η (Tc) is 0.5 at 1% of Tc, and less than 0.25 within 10% of Tc. The change in viscosity is found to vary with the simple energy gap temperature dependence given by (1 − T/Tc)1/2 only within a narrow temperature range 1 − T/Tc ≲ 10−3. The measured η (T)/η (T)c is in qualitative agreement with the results of torsion oscillator experiments. [Work supported by NSF.]
Fourth sound, size effects, and healing length in superfluid He3
Authors: Kojima H. , Chainer T. , Morii Y.
Published: October 2005

Fourth sound was used to measure the depressions of the superfluid component density and the transition temperature of superfluid He3 confined in resonators filled with packed powders. The observed magnitude of the size effects in He3 is much greater than that in He4 [M. Kriss and I. Rudnick, J. Low Temp. Phys. 3, 339 (1970)]. The depression in transition temperature was measured as a function of pressure (12–30 bar) and pore size (0.1–5 μm) and it is found to be consistent with theoretical estimates of healing length. The Q of a fourth sound resonance was also measured as a function of temperature over a limited range. The maximum Q observed was 40. The magnitude of Q appears to be too small to be accounted for by the normal component motion alone. [Work supported by NSF.]
On induced elastic waves in fiber-optic sensors and laser diodes
Authors: Chamuel Jacques R.
Published: October 2005

Experimental observations of induced elastic waves propagating along the optical fibers of fiber-optic hydrophones are presented. Extentional velocities and attenuation coefficients of longitudinal waves measured from single and multimode optical fibers are discussed in relation to fiber-optic hydrophone noise. Experimental observations of magnetostrictively, thermoelastically, and electromagnetically induced elastic waves in laser diode heat sinks and leads are also presented. The importance of the findings is discussed in relation to the interaction between the elastic waves present in both laser diodes and optical fiber sensors, and the potential undesirable acousto-optical modulations in integrated optics where the laser diode is mechanically coupled to the integrated chip. The magnetostrictively induced elastic waves were much larger than the thermoelastic waves in laser diodes using steel heat sinks. The effects of the laser diode heat sink geometry on focusing the elastic waves on the GaAs crystal are examined. The sound field radiated by a pulsed laser placed in a liquid is demonstrated.
Some processes of word recognition in fluent speech
Authors: Salasoo Aita , Studdeft-Kennedy Michael
Published: October 2005

A new technique was developed to study word recognition in fluent speech. Subjects listened to increasing durations of content words in either meaningful or semantically anomalous sentences. Initially each target word was replaced by envelope-shaped noise. In consecutive presentations of a test sentence, 50-ms increments of the original speech waveform replaced either the initial or final segment of the noise until the entire word was presented on the last trial. Subjects attempted to identify the words in the sentences after each presentation. Recognition points and prerecognition word cohorts were collected. Differential reliance on the speech signal was found across the two sentence types. In normal sentences, recognition occurred with less acoustic-phonetic information when the signal increased from the beginning of each target word than when it increased from the end of each target: the mean difference was 55 ms. The difference between forward and backward gating did not occur in the anomalous sentences. Analysis of the word-initial cohorts revealed little overlap between the forward-gated and backward-gated targets, supporting the operation of both top-down and bottom-up sources of knowledge in activating potential word candidates. The results support a class of word recognition models in which both contextual and acoustic-phonetic information interact very early in processing and have as their final product a set of potential lexical candidates that are specified by both the early acoustic-phonetic input and the syntactic and semantic features of the sentence context. [Supported by grants from NIMH and NINCDS to Indiana University.]
Perception of voice pitch in sinusoidal imitations of speech
Authors: Remez Robert E. , Rubin Philip E.
Published: October 2005

Listeners can readily perceive the phonetic value of sinusoidal imitations of speech. These tonal replicas of speech are made by setting time-varying sinusoids equal in frequency and amplitude to the computed peaks of the first three formants of natural utterances. Like formats, the three tones in the sinusoidal signal are not harmonically related, and therefore share no fundamental frequency. Moreover, none of the tones falls within the frequency range typical of Fφ in natural utterances. Naive subjects nevertheless report that the tonal sentences possess noticeable (and weird) voice pitch, and our present study attempted to determine the acoustic basis for the perceived intonation of sinusoidal replicas of speech. In a preference test, listeners judged the tone corresponding to F1 to be more like the voice pitch of a sinusoidal sentence than either: (A) a tone corresponding to F2 or F3; (B) a tone presenting the computed missing fundamental of the three tones; or (C) a tone following the plausible fundamental contour generated by rule from the amplitude envelope of the signal. The results are discussed in terms of our present conceptualizations of the perception of intonation. [Supported by the National Institute of Child Health and Human Development.]
Electrically evoked auditory nerve action potential
Authors: de Sauvage R. Charlet , Cazals Y. , Aran J.-M. , Erre J.-P.
Published: October 2005

Electrical stimulation of the guinea pig cochlea was studied. The same round window electrode was used for both stimulation and recording, with a masking procedure to separate the neural response from the electrical artifact [Charlet de Sauvage et, al., Hearing Res. 2, 343–346 (1980)]. The effectiveness of the electrical stimulation as well as that of the masking noise were monitored using auditory cortical evoked potentials. The artifact cancellation procedure revealed a well-defined response with a very short latency (0.2 ms). The response latency and waveform were constant while varying electrical stimulus intensity, repetition rate, masker level, and spectrum. Little inter-subject variations were noticed. This response was compared with the acoustically evoked compound AP, particularly during combination of acoustical and electrical stimuli. These observations indicated that there is a direct instantaneous electrical stimulation of the nerve, the response of which is thought to represent the mean unit response of the fibers. This approach may be useful in the separate study of cochlear and VIIIth nerve functions and for the analysis (deconvolution) of the compound AP. [Work Supported by INSERM grant 816037.]
Cross-correlation studies of whole nerve action potential waveforms in chinchillas
Authors: Hecker Jamie E. , Relkin Evan M.
Published: October 2005

A cross correlation was calculated for the compound action potential (CAP) response to a tone burst at a given reference frequency at 10 dB above CAP threshold and the compound action potential response to test signals at adjacent frequencies. The normalized cross-correlation coefficient at zero time delay was measured as a function of the test frequency with signal level maintained at the 10 dB level above threshold. Constant CAP peak-to-peak magnitude and constant sound pressure level responses were also correlated with the response to the reference tone burst. Repeating the experimental procedure at several reference frequencies, the correlation coefficients formed band-pass functions centered about the respective reference frequencies. The data were examined for a possible relationship between the bandwidths of the correlation coefficient functions and critical bandwidths and/or frequency difference limens. [Supported by the NINCDS.]
Compound action potential and single unit haversine responses
Authors: Hallworth Richard , Coats Alfred C.
Published: October 2005

The auditory nerve compound action potential (CAP) response to a low-frequency 1-kHz haversine differs dramatically from the more familiar rectangular-pulse (“click”) CAP. The haversine CAP consists of several negative peaks separated by about 1 ms whose latencies shift by about 0.5 ms when the stimulus polarity is reversed. We collected, from cats, haversine-evoked single-unit post-stimulus time histograms (PSTHs) in an attempt to define the pattern of unit activity underlying the haversine CAP. Low characteristic frequency (CF) units have haversine PSTHs similar to click-evoked PSTHs, with interpeak intervals equal to 1/CF. Above a CF of about 1.5 kHz, the interpeak intervals become fixed at about 1 ms, and the responses progressively decrease, in keeping with the reduced spectral density of the stimulus at those frequencies. Units with CF above 5 kHz show little or no response. These observations suggest that the haversine CAP originates primarily from nerve fibers of CF from 1 to 3 kHz. [Supported by NIH and The Pauline Sterne Wolff Memorial Foundation Fund.]
Effects of cholinergic agents on single-unit responses in the rat inferior colliculus
Authors: Farley G. R. , Morley B. J. , Javel E. , Gorga M. P.
Published: October 2005

Cholinergic agents were injected iontophoretically during unit recordings from the inferior colliculi of rats anesthetized with urethane. Prior to drug administration, neurons typically showed little spontaneous activity and possessed nonmonotonic rate-versus-intensity functions for pure-tone stimuli. This was especially true near CF. Maximum driven rate was usually greater for tones below CF than for tones at or above CF. Application of the cholinergic agonist carbamylcholine usually produced dose-dependent decreases in driven rates to CF tones but did not alter response threshold. When injected alone, cholinergic antagonists usually produced dose-dependent increases in driven activity and, at higher doses, generation of “bursty” spontaneous activity. Interactions between agonists and antagonists were common. More units were sensitive to atrophine, a muscarinic antagonist, than to curare, a nicotinic antagonist. Some neurons were sensitive only to curate, and a few neurons were sensitive to both curate and atropine. The data suggest that acetylcholine is not the afferent neurotransmitter in the rat inferior colliculus, but that it mediates a tonically active inhibition which has both muscarinic and nicotinic properties. [Work supported by NINCDS grant NS-14880 and NSF grant BNS-8006643.]
Adaptation of the brainstem evoked response
Authors: Weatherby Lynn , Hecox Kurt
Published: October 2005

The adaptation of the Brainstem Evoked Response is described as a function of interstimulus interval, intertrain interval, and intensity. Averaged responses to each click of a train of eight are compared. The largest wave V latency increase is found between the first and second click, with subsequently smaller latency increases until an asymptotic level is reached by the fourth click in the train, thus confirming earlier observations [M. Don, A. R. Allen, A. R. Starr, Ann. Otol. 86, 186–195 (1977)]. Varying the interstimulus interval (11.1, 20, 100 ms) produces an increasing adaptation function as the interstimulus interval decreases, but there are no intertrain interval effects (250 versus 750 ms) on these same parameters. The difference in the amount of adaptation as a function of interstimulus interval is apparent but not complete by the second click in the train. The effects of stimulus intensity (30, 45, 60, 70 dB n HL) are complex. The adaptation function increases with increasing intensity, with the exception of the 70-dB condition where the function is similar to that at 30 dB n HL. The relative effect of latency versus intensity in producing this phenomena will be discussed. [This work is supported by NIH.]
Changes in evoked-response tuning curves with varying levels of hearing loss
Authors: Salvi Richard , Shaddock Lynn , Ahroon William H. , Henderson Don
Published: October 2005

Evoked-response tuning curves from chinchillas were measured before and after exposure to an octave band of noise (CF = 0.5 kHz) that produced an asymptotic threshold shift (ATS) which was nearly flat from 0.5 to 16 kHz. The hearing loss was systematically increased from roughly 15, 30, and 45 dB by increasing the level of the noise from 75, 85, and 95 dB SPL. Tuning curves were measured in awake animals using a simultaneous masking paradigm. As hearing loss increased, there was a progressive broadening of the tuning curve; little or no tuning was present after the highest noise exposure. The systematic loss of tuning will be related to behavioral and single unit tuning curves obtained with the same noise exposure. [Work supported by NINCDS, USAR.]
Frequency dependence of the binaural interaction component of the auditory brainstem response
Authors: Fowler Cynthia G. , Leonards Janet S.
Published: October 2005

The purpose of this study was to determine whether high- or low-frequency stimuli are responsible for generating the binaural interaction component of the auditory brainstem response. The binaural interaction was determined in nine subjects with normal hearing and nine subjects with cochlear hearing losses. Stimuli were 1000- and 4000-Hz tone pips at 100, 80, and 60 dB peSPL. Results indicated that 4000 and 1090 Hz at 100 dB peSPL produced reliable binaural interaction in normal and cochlear-impaired subjects, regardless of the configuration of the loss if the stimuli were ⩾15 dB SL. The binaural interaction was elicited at 1000 Hz in subjects with precipitous high-frequency hearing losses that precluded responses to 4000 Hz. No binaural interaction was generated in subjects with unilateral profound hearing losses, or with asymmetrical hearing losses that effectively rendered the binaural stimuli monaural. Both high- and low-frequency stimuli, therefore, can generate the binaural interaction component of the auditory brainstem response. Further, a cochlear hearing loss does not preclude the binaural interaction component. [Work supported by Veterans Administration RAGS.]
Binaural properties of neurons in the chinchilla lateral superior olivary nucleus
Authors: Moore Maurus J. , Caspary Donald M.
Published: October 2005

Neurons in the chinchilla lateral superior olivary nucleus (LSO) were studied as part of a broader study of neurotransmitters of the superior olivary complex (SOC) [Moore et al., Neurosci. Abs. 7, 389 (1981)]. Two hundred thirty neurons, localized to an area lateral to the medial superior olive, were classified according to their responses to monaural and binaural stimulation at characteristic frequency (CF). Forty-two percent of the neurons were monaurally excited (predominantly ipsilaterally) and binaurally inhibited. Eight percent of the neurons displayed excitation when either ear was stimulated and inhibition upon binaural stimulation. Sixteen percent were excited when either ear was stimulated and displayed a summated binaural response. A smaller population of neurons (5%) was excited by either ipsi- or contralateral stimulation and displayed an enhanced binaural response. Poststimulus time and interspike interval histograms were obtained for all conditions. Response patterns in the chinchilla are consistent with findings described for other previously studied species. [Work supported by NIH Grant NS15640, SIU CRC funds and Pearson Family Foundation.]
Effect of cholera toxin upon cyclic AMP (cAMP) levels in tissues lining cochlear duct
Authors: Thalmann I. , DeMott J. E. , Ge X.-X. , Thalmann R.
Published: October 2005

Feldman and Brusilow [Proc. Natl. Acad. Sci. USA 73, 1761 (1976)] reported that endolymphatic injection of cholera toxin (adenylate cyclase stimulator) results in endolymphatic hydrops, the pathological substrate of Ménière's disease. The authors postulated that the situation is similar to the intestine, where the cholera toxin mediated elevation of cAMP levels causes profuse fluid secretion. We found that perilymphatic application of cholera toxin caused an approximately 2× increase of cAMP in Reissner's membrane (RM), but no significant changes in stria vascularis (SV) and organ of Corti (OC). Endolymphatic perfusion produced no changes. However, when cholera toxin, in combination with theophylline (phosphodiesterase inhibitor) was perfused perilymphatically, a dramatic increase in cAMP levels occurred in RM (80×), a substantial increase in OC (8×), but only a small increase in SV (2×). Endolymphatic perfusion caused a 20×, 4×, and 3.5× increase, respectively. These results indicate that RM may be more important in cochlear fluid homeostasis than generally assumed. Note, however, that the relatively low level of strial cAMP may be due to clearance via the vasculature. [Supported by NIH.]
Studying a guitar's radiation properties with nearfield holography
Authors: Strong William Y. , Beyer T. B. , Bowen D. J. , Williams E. G. , Maynard J. D.
Published: October 2005

Recent studies of an intact string-excited guitar have shown that the motion of the air in the rose is quite significant over the first two octaves of the instrument's range. Our nearfield holography technique has revealed that the rose is a dominant source of the radiated energy. We have found that modeling the guitar as a rigid cavity with flexible top plate and a sound hole is not accurate. The motion of the back plate in the guitar studied was quite significant, with amplitudes across it 2–3 times greater than at the top for the lower frequencies, and therefore should not be ignored in subsequent studies. Additionally, accepted plate modes seem to occur at more than one frequency in the string-excited guitar. The recurrence of these modes may tend to smooth out the frequency response curve, and a better understanding of this effect may lead to a more well balanced instrument.
Measurements of ultrasonic scattering from flaws near a liquid-solid interface
Authors: Hsu D. K. , Gray T. A. , Thompson R. B.
Published: October 2005

Experimental measurements of the ultrasonic scattering from voids and inclusions near a liquid-solid interface are reported. Measurements were made in a pulse-echo mode, using a transducer immersed in the liquid medium. Scatterers in the solid included an oblate spheroidal void, well removed from the interface, and spherical and prolate spheroidal inclusions, on the order of a scatterer radius away from the interface. The results are interpreted in terms of newly developed theoretical calculations for subsurface flaws [V. V. Varadan, V. K. Varadan, T. A. K. Pillai, R. B. Thompson, and D. Hsu, J. Acoust. Soc. Am. Suppl. 1 71, 82 (1982)]. Comparisons of the absolute scattering amplitudes are made in terms of frequency, flaw-to-surface distance, ultrasonic mode, and scattering angle. For the particular parameters of the near surface case studied in this work, spectral variations of the signal are dominated by the interferences of L→L, L→T, and T→T scattering from the flaw rather than multiple scattering between the flaw and surface. However, this is not viewed as a general conclusion, and a simple estimate of the magnitude of the multiple scattering process is made. [Work supported by Center for Advanced NDE, operated by Ames Laboratory, USDOE, for AFWAL and DARPA under contract No. W-7405-ENG-82 with Iowa State University.]
Reversed sonority in Pashto initial clusters
Authors: Bell Alan , Saka Mohamed M.
Published: October 2005

Pashto possesses both resonant clusters of rising sonority such as lw- and clusters of reversed sonority, such as wl-. The highly preferred status of the first clusters has been incorporated in the syllabic theories of Bybee Hooper, Vennemann, Fujimura and Lovins, and Kiparsky. The question arises whether the dispreferred clusters manifest phonetic adaptations to compensate for their reversed sonority. The clusters ml-, lm-, lw-, wl-, and wr- and the singlet initials m-, l-, r-, and w- were analyzed. Waveforms and LPC spectral analyses were obtained for 120 tokens recorded by the second author, using the Haskins Laboratories speech analysis programs. No frication was observed for any onset. All onsets were partially devoiced. The devoicing duration depended only upon the initial segment, not the sonority type of the cluster it began. Comparing the segment durations of the preferred ml- and lw- clusters to the reversed lm- and wl- clusters showed that the more sonorous segments were relatively longer beginning reversed clusters than ending preferred ones; the less sonorous segments showed the opposite relationship. No adaptation to reversed sonority was found. [NICHD support acknowledged.]
Fitting long vowels and stops into the mora in Japanese
Authors: Port Robert F. , Dalby Jonathan
Published: October 2005

Earlier studies of two syllable words demonstrate that segment durations in words are contextually adjusted so as to yield word durations that are nearly equal despite differences in the inherent durations of the vowels and consonants that make up the words. The present experiment compares the temporal structure of a pair of two-more CVCV words to that of three pairs of three-mora words of three different types; a pair that has an “extra” vocalic mora (CVVCV), a pair that adds a consonantal more (CVCCV), and a third pair that adds a syllabic more (CVCVCV). Within each pair the medial stop differs in voicing. The results show that adjustments are made between adjacent morae, not just between adjacent segments, to compensate for inherent differences in mora durations. This problem arises since a segmental mora (i.e., long V or C) is shorter than a syllabic mora (CV), yet the durations of all three words containing them were found to be nearly equal. Furthermore, the adjustments at the mora level are made independently of the effects due to adjustments at the segment level. [Work supported by NIH.]
Differences among retroflex consonants
Authors: Ladefoged Peter , Bhaskararao P.
Published: October 2005

Both Dravidian languages such as Telugu and Indo-Aryan languages such as Hindi have contrasts between dental and retroflex consonants. But what is called retroflex in Telugu is not the same as what is called retroflex in Hindi. X-rays of five speakers of each of these languages producing minimal pairs exhibiting these contrasts show that the tongue tip is curled further up and back in the Telugu retroflex consonants than in those in Hindi. The dental consonants in the two languages are more similar. The articulatory differences are reflected in the acoustic data. As expected the formant transitions for the Telugu retroflex consonants involve a greater lowering of the third formant. These results appear to be contrary to the predictions of the quantal theory of speech production, which suggests that there should not be small but significant variations in the articulation of such consonants.
Relationship between stress and F0 in Spanish
Authors: Massone Maria Ignacia
Published: October 2005

The relationship between stress and F0 as manifested by the F0 curve in declarative and interrogative Spanish sentences is quantified. The material under study were the F0 curves of 20 declarative sentences and four yes-no questions. The peaks and changes of F0 of stressed syllables were measured on the F0 curves and the duration of each segment on spectrograms. Three levels of stress were determined on several key content words. In declarative sentences the high level is manifested by the F0 maximum: 138.42 Hz, and by the greatest F0 change with respect to the preceding syllable: 30.42 Hz. The middle level presents the second F0 peak: 124.5 Hz and a smaller change: 26.5 Hz. The low level is marked by a greater vowel and consonant duration. The yes-no questions show a greater F0 change and a higher overall frequency of the F0 curve with respect to statements. Therefore, the pattern of interrogative sentences cue distinguishes a question from a statement. Results suggest that stress is marked by different cues according to the level of stress of the content words and to its position within the F0 curve.
Monitoring speech production in a foreign language
Authors: Flege James Emil
Published: October 2005

This study examined production by native and non-native speakers of French “tu” (ty) and “tous” (tu) in the absolute-initial position of phrases that: (1) were read from a list; (2) initiated spontaneously generated sentences; and (3) initiated sentences in a spontaneous story. If paying attention to speech improves performance, production should be more native-like in condition 1 than 3. However, no effect of speaking condition was observed in a listening test in which “tu” and “tous” were presented in pairs to French-speaking Americans. Higher correct recognition rates were observed for native French than American speakers, and for advanced compared to intermediate Americans. Labeling by native French listeners also indicated much better performance by native than non-native speakers. Recognition rates were higher for the advanced than intermediate Americans for “tous” but not “tu”, with a tendency for better recognition in condition 1 than 3 for “tous” produced by both groups of Americans. Examination of F2 showed no overlap between /y/ and /u/ for vowels produced by the native speakers; little overlap for the advanced Americans; and nearly complete overlap between the /u/ and /y/ produced by the intermediate Americans due to the high F2 of their /u/.
Stress and tongue blade movement in alveolar VC gestures
Authors: Laferriere Martha
Published: October 2005

Displacement, peak velocity, and movement time of the tongue blade in VC transitions were studied using data obtained by a computer-controlled x-ray microbeam system [cf. Laferriere and Fujimura (1981)]. Consonants were /t/ and /d/; vowels were either stressed, or unstressed/reduced. Displacement was the distance moved by the blade pellet from a zero-velocity state for the vowel to the next zero-velocity state for the consonant. A positive relationship was found between displacement and velocity [cf. Kuehn and Moll (1976)]. However, when C was a stop, for a given displacement, blade movement was faster from an unstressed vowel than from a stressed vowel. When C was a tap, for a given displacement, blade movement was faster when the following vowel was unstressed ([∇́ɾə]) than when it was stressed ([∇́ɾ∇́]). For both stops and taps, movement time was shorter in the unstressed cases. These results indicate that (1) velocity and movement time of the tongue blade are conditioned by degree of stress, and (2) the broader stress environment (post-consonantal vowel) may also affect articulatory movement of the pre-consonantal transition.
Articulatory strategies for combining vocalic elements
Authors: Bell-Berti Fredericks , Raphael Lawerence J.
Published: October 2005

Sequences of vowels in English are perceived (and, presumably, produced) variously, depending upon their linguistic functions. Thus, [i] and [ɔ] can be combined to produce: (1) a one-syllable, one-phoneme unit such as the diphthong in boy; (2) a one-syllable, two-phoneme unit (in which the first vocalic element functions as a consonant) such as the glide-plus-vowel sequence in yawn; (3) a two-syllable, two-phoneme unit such as the vowel sequences in I see Audie and I saw Edie. An electromyographic study of intrinsic and extrinsic muscles of the tongue has yielded a preliminary description of the articulatory strategies used to differentiate these combinations of vocalic elements. [Research supported by NINCDS.]
One-stage and two-stage temporal patterns of velar coarticulation
Authors: Al-Bamerni Ameen , Bladon Anthony
Published: October 2005

Previous observations of the coarticulatory spread of nasality from a nasal consonant to adjacent vowels have yielded some contradictory evidence and two contradictory hypotheses: (a) coarticulatory timing is determined by segmental content and (hi coarticulation is coordinated in time with a particular articulatory gesture. Using transillumination of the velopharyngeal port, the timing patterns of velum opening were investigated in (C)VN, (C)VVN, and (C)VVVN sequences in languages lacking contrastively nasalized vowels. It was found that all speakers used two distinct patterns of velum opening, though with different frequencies of occurrence: first, a single opening gesture of smoothly increasing amplitude, its onset aligned with the first vowel onset irrespective of intervening boundaries; and second, a two-stage opening gesture whose absolute onset was aligned as previously but whose higher-velocity second stage was coordinated with the oral closing gesture for the nasal consonant. Thus we may have to recognize that speakers have available two alternative production strategies.
Some acoustic characteristics of Parkinsonian dysarthria
Authors: Weismer Gary
Published: October 2005

The early stages of Parkinsonian dysarthria are often thought to be characterized primarily by laryngeal dysfunction, whereas in later stages a progressive deterioration of supraglottal articulatory function is observed. Most previous analyses of Parkinsonian dysarthria have employed phonetic transcription as a descriptive device, but a few recent papers [e.g., Tatsumi et al., Ann. Bull. RILP 13, 99–104(1979); Kent and Rosenbek, Brain Lang. 15, 259–292 (1982)] have reported some more objective data based on acoustic measures. In the present study, we analyze acoustically the temporal structure of sentence recitations produced by ten Parkinsonian dysarthrics. These data are compared to existing data sets for the same utterances produced by normal young adults and geriatrics. Results indicate that the temporal characteristics of the Parkinsonian sentence recitations are only subtly different from those of young adults and geriatrics. However, the spontaneous speech of the Parkinson's patients have clearly aberrant temporal structures. The findings are discussed relative to the general pathophysiology of Parkinson's disease. [Work supported by NIH Program Project NS 13274.]
Pressure patterns in the nearfield of a diffracting sphere
Authors: Waterhouse R. V.
Published: October 2005

A steady train of plane waves impinges on a sphere. The nearfield diffraction patterns for the normalized rms pressure were computed for values of ka from 1.5 to 6, where k is the wavenumber and a is the radius of the sphere. Charts are given, showing the contours of rms pressure for ka = 1.5, 2, 3, 4, and 6, for each of two boundary conditions, pressure reflecting and pressure release. Each chart shows the contour pattern out to a distance of ten radii. The computed expressions are infinite series containing spherical Bessel functions and their gradients. In some eases 75 terms in the series must be evaluated to get convergence to within 1%. The charts show that there are substantial areas where the pressure differs from the undisturbed value by 6 dB or more.
“Whispering” waves in a wine glass
Authors: Apfel Robert E.
Published: October 2005

The circular motion of a wet finger on the rim of a wine glass that results in the familar resonance of the glass with the accompanying radiation of a tone is also responsible for the launching of circular capillary waves (wavelength ∼1 mm) on the surface of the liquid (wine, or other). These waves interfere to produce visible ripples that are nearly stationary relative to the moving finger and that have the interesting feature of being confined to a region near the outer perimeter of the glass. Such waves are analogous to the whispering galley, “aerial” waves that Lord Rayleigh speaks of in one of his many classic papers [Philos. Mag. 20, 1001–1004 (1910)]. The width of the confined region, which is much less than the radius of the glass, is accurately predicted by Rayleigh's formula for circular membrane waves. Moreover, because the width of the waves is small, the waves can be considered to be one dimensional—a feature that may suggest the application of this phenomenon to the study of others. Demonstration of these waves will be given during the session (as well as at dinner).
Radiation pattern analysis of acoustical scattering from elastic objects immersed in a fluid
Authors: Werby M. F. , Green L. H. , Flax L.
Published: October 2005

Resonance patterns at different aspect angles can be quite complicated and consequently difficult to analyze for a variety of geometrical shapes. A theoretical study based on form function calculations can be both costly, time-consuming, and subject to ambiguity for a variety of aspect angles. We argue that it is possible to perform a sequence of radiation pattern calculations that prove useful in determining resonances at various aspect angles and illustrate this procedure with a number of calculations using computer codes recently developed at NCSC.
Resonances of elastic spheroidal bodies
Authors: Green L. H. , Werby M. , Flax L.
Published: October 2005

The calculation of the resonances [L. Flax, G. C. Gaunaurd, and H. Uberall, Theory of Resonance Scattering, in Physical Acoustics, Vol. XV, edited by W. P. Mason and R. N. Thurston (Academic, New York, 1981)] of elastic bodies immersed in a fluid is a topic of current interest. In this paper the T-matrix approach is applied to the scattering of plane acoustic waves incident upon spheroidal elastic bodies immersed in water. Various aspect ratios and shell thicknesses will be treated. The wavenumber of the incident wave will satisfy 5⩽kL/2⩽12, where k is the wavenumber for the incident sound wave and L/2 is the semi-major axis of the spheroidal body.
A new hybrid T-matrix-boundary element approach for elastic shell scattering problems
Authors: Varadan V. V. , Eswaran K. , Varadan V. K.
Published: October 2005

A new method is proposed and implemented for the study of acoustic wave scattering by thin elastic shells of revolution submerged in a fluid. Using the conventional T-matrix approach for layered scatterers, difficulties were encountered in the past as the shell thickness decreased and the eccentricity of the object increased. This has then been overcome for the case of elastic shells by invoking elastic thin shell theory to characterize the response of the shell to an incident harmonic wave. This has then been coupled with the T-matrix approach to arrive at a solution for the solution scattering problem. Very encouraging numerical results have been obtained for a finite cylindrical shell with spherical end caps that is immersed in water. The frequency spectrum has been interpreted by computing the free vibration frequencies of the shell and are now being compared with the experimental results of S. K. Numrich and L. Dragonette of the Naval Research Laboratory, Washington, DC.
A new T-matrix approach for acoustical scattering from elastic shells immersed in a fluid
Authors: Werby M. F. , Green L. H. , Flax L.
Published: October 2005

We derive equations using the T-matrix approach for acoustical scattering from elastic shells immersed in a fluid. The equations contain unitary and symmetry constraints and afford a new procedure for the calculation of the T-matrix. The technique, in addition to satisfying symmetry and unitary conditions, proves to be more numerically stable and less time consuming than the conventional method. In addition, the procedure enables one to determine if convergence has been satisfied and in the limit of no convergence, it proves to be a better approximation than that of the matrix method. We have developed computer codes using the new technique and present comparisons with the conventional procedure. A salient feature of the new technique is that convergence is arrived at with a smaller number of expansion terms than the older method and this is particularly true as the aspect ratio of the target is increased.
Reference equivalent threshold sound pressure levels at 5 and 6.3 kHz using telephonics TDH 39 earphones with MX-41/AR cushions
Authors: Benwell D. A. , Hussey R. G.
Published: October 2005

Reference equivalent threshold sound pressure levels (RETSPLs), were measured at 5 and 6.3 kHz using Telephonics TDH 39 earphones with MX-41/AR cushions. The purpose of the test was to verify RETSPL values calculated by interpolation from those specified in present International Standards Organization acoustics standards, ISO 389 “Standard reference zero for the calibration of pure-tone audiometers,” and its amendments. The RETSPL values are intended for the calibration of audiometers using pure tones of fixed frequencies at the preferred frequencies in one-third octave steps or pure-tone audiometers having a continuously variable frequency. Mean measured values of RETSPL's at 5 and 6.3 kHz were 10.9 ± 2.6 and 15.1 ± 2.4 dB, in comparison to predicted values which were 13 and 15 dB, respectively.
Optimizing modulation rate and waveform for frequency-modulated sound field audiometric stimuli
Authors: Dillon Harvey , Walker Gary
Published: October 2005

Narrow-band stimuli used for audiological sound field testing should satisfy three conditions: (1) have a uniform distribution of power within the band; (2) have a rapid falloff of power outside the band; (3) have amplitude fluctuation (resulting from the rooms transmission response) which are fast enough to be fully integrated by the ear. The first condition ensures that stimuli of a given bandwidth will produce a reverberant field which is as uniform with distance as possible. For fm stimuli, it is well met by the use of triangular or ramp modulation waveforms. The second condition is important if people with steeply sloping hearing thresholds are not to have their hearing loss underestimated. Sinusoidal modulation waveforms met this condition well and triangular waveforms acceptably so. For the hearing impaired, with reduced temporal integration functions, the last condition is not well met by the usual 5-Hz modulation rate. If the rate is made too high, condition (1) is violated. The optimum rate appears to be about 20 Hz and the optimum waveform is triangular.
The speed of sound in epoxy resin blends and composites
Authors: Montgomery Robert E. , Weber Fred J. , White David F. , Thompson C. M.
Published: October 2005

Sound speeds in two types of diamine-cured epoxy resin blends were determined as functions of frequency, temperature, and composition, and the feasibility of impedance matching through the addition of microballoon fillers was also demonstrated. A filled resin system based on a diglycidyl ether of poly (propylene glycol) was shown to possess a mass density near 1.0 g/cm3 and propagate sound at speeds near 150 m/s, while a resin system based on a diglycidyl ether of bisphenol A exhibited sound speeds and specific acoustic impedances about twice those of water. Although the incorporation of microballoons slightly increased sound speeds, the corresponding density reductions resulted in a net decrease of the specific acoustic impedance in all instances. [Work supported by NAVSEA 63R.]
Two-factor theory of auditory organization
Authors: Bregman Albert S.
Published: October 2005

Evidence from several laboratories suggests a generalization that organizes several facts about auditory organization. It goes as follows: There are two “forces” of primary perceptual organization, a sequential one that organizes acoustic components sequentially into streams, and a simultaneous one that fuses components into pitch and timbre structures. Each of these forces draws its basic information from a separate physiological mechanism. The sequential force directly draws upon the place coding of the basilar membrane (BM). The simultaneous force is based upon timing information carried on neural outputs from the BM. Since the two forces compete, the factors that influence each can affect the other, but only indirectly. A parallel dichotomy is proposed for pitch: pitch height is controlled by BM place information while chroma is based on timing information. Hence pitch height should appear to influence sequential organization, and chromatic relations to affect fusion. Musical schemata can override these perceptual forces, but only at slow rates of presentation of sound.
Rhythmic and melodic strutures in perceptual space
Authors: Carterette Edward C. , Monahan Caroline B. , Holman Eric , Bell Theodore S. , Fiske Robert A.
Published: October 2005

By asking a person to say how much or how little alike two musical forms are, one can infer the dimensional properties of that person's musical space. We asked musically trained listeners to rate the similarity of pairs of brief melodies on a 9-point scale. Each of four different melodies and their inversions was played in each of four duration patterns (anapestic, dactylic, iambic, and trochaic) for a total of 1024 pairs of patterns. Multi-dimensional scaling and cluster analyses of the similarity matrices showed that at least five dimensions were necessary for giving a good account of the perceptual space of these musical structures. Surprisingly, the major dimensions were rhythmic, thus (using INDSCAL): (i) accent early or late, (ii) duple or triple meter, (iii) iambic-dactylic versus anapestic-trochaic. Other dimensions were (iv) rising versus falling pitch and (v) number of pitch-interval reversals. Cluster analysis suggests that some spaces have duple and triple meter as main branches, while others have accent first and accent last as main branches. Decision times (DT) were an inverted-U function of similarity (S). The curve, when folded about S = 5, was well fit by the power function DT(ms) = 737S027, with a coefficient of determination R2 = 0.98.
Musical key structure and its influence on perceived harmonic relations
Authors: Krumhansl Carol L.
Published: October 2005

A structural description of musical key distance was derived from the tone-profile technique in which listeners rate how well each chromatic-scale tone follows a key-defining element (scale, tonic triad chord, or chord cadence). The rating profiles, reflecting the music-theoretic hierarchy of tonal stability, were shifted to all possible tonics, intercorrelated, and analyzed using multidimensional scaling. The four-dimensional solution placed the 24 major and minor keys on a torus simultaneously accommodating the circle of fifths and relative and parallel relations between major and minor keys. Two subsequent experiments investigated the effect of interkey distance on perceived harmonic relations between chords. The magnitude of three independent context effects (measured in both direct relatedness judgments and memory confusions) was found to depend systematically on the distance between the keys in which the chords function and the key of the broader context in which they are embedded. The results provide strong evidence that listeners interpret chords in their tonal functions and have internalized structure at the level of abstract tonal centers. [Work supported by NSF.]
Electron-acoustic microscopy
Authors: Cargill G. S.
Published: October 2005

Electron-acoustic microscopy is a technique which combines electron beams and ultrasonics to examine spatial variations in thermal and elastic properties of solids on a microscopic scale [G. S. Cargill III, Nature 286, 691 (1980); Phys. Today 34, 27 (Oct. 1981); E. Brandis and A. Rosencwaig, Appl. Phys. Lett. 37, 98 (1980)]. A focused electron beam is chopped at kHz or MHz rates to generate ultrasonic waves by thermoelastic expansion at the front surface of a specimen, and these are detected by a piezoelectric transducer bonded to the specimen. The transducer output is used to form a scanned, magnified image containing near-surface and subsurface information which is not accessible in conventional optical or electron microscopy. This mode of ultrasonic imaging in scanning electron microscopy may be called electron-acoustic microscopy in analogy with photoacoustic microscopy [G. Busse and A. Rosencwaig, Appl. Phys. Lett. 36, 815 (1980)] in which a laser is similarly used to generate acoustic or ultrasonic waves. However, the electron beam can be focused to a much smaller spot than is possible with visible light, yielding improved spatial resolution. [This work was begun at the University of Cambridge, with support from the Science Research Council and Churchill College.]
Ultra-deep subharmonics in high amplitude shallow water waves
Authors: Keolian Robert , Rudnick Isadore
Published: October 2005

When a horizontal annular channel containing water is parametrically excited by oscillating it vertically with moderately high amplitude at a frequency f≃10 Hz, then under appropriate conditions nearly periodic subharmonics of frequency f/2000 are generated. [Earlier work on this problem can be found in Phys. Rev. Lett. 47, 1133 (1981)]. This oscillation is robust and has been observed continuously for a period of 30 h (a million cycles of the driving frequency). The basic nature of the oscillation is that of a modulated f/2 mode. In another experiment when waves in a linear trough are driven by a horizontally oscillating paddle, a modulated f/3 mode is observed with a basic subharmonic of approximately f/100. The pattern of the motion as shown by a strip chart recorder has the appearance of an intricate braid. Other ultradeep subharmonics have also been observed. The origin of these subharmonics will be discussed and a videotape will be presented. [Work supported by ONR.]
Nonlinear thermoacoustics and electrostriction explanations of acoustic signatures in 4 °C water caused by laser pulses and proton beams
Authors: Pierce Allan D.
Published: October 2005

Experiments in water with proton beams [Hunter et al., J. Acoust. Soc. Am. 69, 1557–1562 (1981)] and with laser pulses [Hunter, Jones, and Malbrough, J. Acoust. Soc. Am. 1563–1567 (1981)] give pressure signatures superimposed of a bipolar signal (reversing polarity at 4 °C) and an anomalous tripolar signal that at onset is (1) negative (proton beams) or (2) positive (laser pulses). The explanation for (1) is that charge added by a proton beam causes a surrounding short-lived electric field that, via electrostriction, initially accelerates fluid inwards and temporarily lowers pressure in an annular region and raises it in the core. Such causes a minus-plus-minus-plus shaped signature varying inversely with electrical conductivity. The explanation for (2) ensues from a formulation that uses the thermal expansion coefficient's temperature dependence. Such yields an additional source term (nonzero at 4 °C and proportional to negative of second time derivative of square of heat added per unit volume) to inhomogeneous wave equation, resulting in initially positive signature. Pulse durations and charge relaxation times are assumed short compared to acoustic transit time across diameter, so all signature time scales are of order of latter. Rough numerical estimates are not inconsistent with reported crossovers in initial polarity at 6° and 3 °C, respectively. The small second positive peak in the tripolar signal and the precursors in the laser beam experiments are still not understood. [Work supported by ONR.]