bluuebunny/crossref_metadata_2025 huggingface dataset:
Annoyance and acceptability judgments produced by 32 aircraft noise conditions
Authors: Borsky Paul N.
Published: October 2005

The varying effects of aircraft noise and human response variables on annoyance responses were measured in a major laboratory study of 384 subjects. About half of all variance in annoyance is explained by level and spectrum of noise, type of subject's activity, and real environment exposures. Level of noise accounts for 30% of all variance and 60% of all explained variance. Type of subject's activity accounts for 12% and his type of real environment exposure accounts for 8% of explained variance. Annoyance under TV viewing and listening was greater than under rest and relaxation. Residents normally exposed to lower levels of aircraft noise were more annoyed by noise than residents living closer to the airport and regularly exposed to higher noise levels. The correlation between Leq and 1536 annoyance judgments was r = 0.53, with each unit of annoyance on a 0–9 scale associated with 6.25 units of Leq. One experimental condition which included full retrofit of 747s and 727s and replacement of noisy 707s by quieter L-1011s, was still found unacceptable by two-thirds of subjects for close level exposures.
On the measurement of abnormal loudness growth
Authors: Pavel M. , Iverson G.
Published: October 2005

The measurement of recruitment and recruitmentlike phenomena is of interest not only for its clinical applications, but more generally as providing constraints on models for the peripheral coding of intensity. In this paper we analyze the results of matching tasks which generate abnormal loudness growth functions from normal subjects by employing a continuous unilateral background noise. Within the framework of a particular functional representation for the masked loudness growth an empirical observation (shift invariance) is found to be so constraining as to completely determine the analytic form of the loudness growth, up to a set of measurable parameters. This analytic form involves a certain combination of power functions of both signal and noise levels, refining earlier conjectures [S. S. Stevens, J. Acoust. Soc. Am. 39, 725–735 (1975)]. The usual analysis of data from the clinical test procedure MBLB is placed on a firm basis.
Experimental test of a predicted relation between intensity discrimination and loudness matching
Authors: Houtsma A. J. , Durlach N. I. , Braida L. D.
Published: October 2005

According to previous theoretical work on intensity perception, two stimuli are matched in loudness if and only if their intensities divide the respective dynamic ranges of the stimuli proportionately in terms of number of JNDs [R. R. Riesz, J. Acoust. Soc. Am. 5, 211–216 (1932); J. S. Lim, W. M. Rabinowitz, L. D. Braida, and N. I. Durlach, J. Acoust. Soc. Am. 62, 1256–1267 (1977)]. This paper reports the results of new experiments designed to test this prediction using a common set of subjects and comparable experimental conditions. Intensity discrimination data and loudness-matching data were obtained on four subjects over essentially the whole dynamic range for three types of stimuli: a 1000-Hz tone, a 1000-Hz tone partially masked by noise, and a flat wide-band noise. Generally speaking, the empirical loudness matches were found to agree with the loudness matches predicted by the theory on the basis of the discrimination data. [Work supported by NIH and NSF.]
Locua of adaptation effects for the voicing feature
Authors: Niccum Nancy , Speaks Charles
Published: October 2005

Eight listeners participated in two experiments. The first tested for simultaneous dichotic adaptation by obtaining monaural identification functions before and after adaptation with /ba/ and /pa/ presented dichotically. The difference between the number of/ba/responses for left- and right-ear postadaptation identification was significant. The second experiment assessed the magnitude of interaural transfer. Adaptation and identification stimuli were presented monaurally and identification shifts for the unadapted ear were compared with those for the adapted ear. When /ba/ was the adapting stimulus, only 62%–65% transfer was obtained, but the difference between ears was nonsignificant. When /pa/ was the adapting stimulus, 51%–52% transfer was obtained and the difference between ears was significant. The failure to each significance for the /ba/ conditions may relate to the smaller absolute size of shifts in identification. In general, the results of both experiments provided evidence for a bilateral component, either peripheral or central, to the adaptation effects for voicing. These findings are contradictory to those reported by Eimas et al. [Percept. Psychophys. 13, 247–252 (1973)]. [Supported by PHS NS-12125.]
Microsurgery of the ear: The Robinson stainless steel stapes prosthesis to restore hearing in otosclerosis
Authors: Robinson Mendell
Published: October 2005

The development and surgical use of the Robinson stainless steel stapes prosthesis for the treatment of hearing loss in otosclerosis will be presented. Over 4000 operations have been performed by the author to date with a success rate of 97%. The anatomy, physiology, and surgical pathology will be presented on color slides, as well as the surgical technique and statistical results. A color motion picture will illustrate the actual microsurgery as observed through the operating microscope. This technique is now one of the most frequently used stapedectomy techniques in the country, with over 10 000 surgical operations performed each year using this prosthesis.
Identification of apical stops as a function of instructions to perceive a preceding stimulus as either a speech or nonspeech sound
Authors: Moroff Debra A. , Curtis J. F.
Published: October 2005

This study investigated the influence of an ambiguous stimulus on the identification of a series of synthetically produced syllables having voice onset time and aspiration characteristics which varied between those appropriate for /da/ and /ta/. One group of 12 subjects was instructed that a 70-ms high-frequency noise burst which preceded the syllable by 40 ms represented the consonant /s/. A second group of 12 subjects was told that the noise burst represented a nonspeech noise. A third control group received no biasing instructions. Subjects instructed to perceive the ambiguous stimulus as /s/ identified the following stop as /t/ more often than those in the nonspeech noise group. Mean reaction time for identification of /t/ was longer than for /d/ in the context of the noise burst for both the speech and control groups, but not for the noise group. The results suggest that phoneme categorization is not based on acoustic properties alone. Consequences for a feature-detector model of speech perception are discussed.
Effects of word-internal versus word-external tempo on the voicing boundary for medici stop closure
Authors: Port Robert F.
Published: October 2005

It is known that the perceived voicing of the medial stop in words like rabid and rapid can be controlled by changing the duration of the stop closure. We found [R. Port, J. Acous. Soc. Am. 59, S41–S42(A) (1976)] that increasing the tempo of a preceding carrier sentence shortened the boundary between rabid and rapid along a continuum of silent closure durations, but by far less than the percent decrease in sentence duration. We hypothesized that timing in unaltered portions of the test word reduced the effect of the carrier tempo. This experiment directly compares the effect on this boundary of the tempo of a surrounding carrier when the tempo of the test word itself is changed. A speaker recorded “I'm trying to say rabid to you” at both fast and slow tempos. Rabid was excised from each, and two continua of silent /b/ closures were prepared (from 50 to 200 ms) and embedded in both original sentences. Listeners identified the test words as either rabid or rapid. Results indicate (1) tempo within the test word had a stronger effect on the boundary than tempo in the carrier, and (2) for a given tempo of carrier, the ratio of the boundary value of closure duration to the duration of the rab syllable was nearly constant for both rab durations.
Some experiments on the recognition of voiced stop consonants in CV and VCV syllables
Authors: Raphael Lawrence J. , Dorman Michael F.
Published: October 2005

When listeners are asked to identify CVs in which the burst and transitions signal different places of articulation, the majority of responses are determined by the transition cues. In the present set of experiments we focus on those situations in which the burst dominates in perception. Even in these situations, we have found that the burst cue can be “overridden” by transition cues if VCVs are created in which the implosive and explosive transitions cue the same place. We infer from this outcome that the decision about place of articulation is not made solely on the basis of the shape of the burst (onset) spectrum, but, rather, is made on the basis of spectral information which both precedes and follows the onset.
On the perception of nasal consonants
Authors: Henderson Janette
Published: October 2005

The problem of perceptual constancy was investigated with respect to the variation in acoustic cues for the place of articulation of nasal consonants in English as a function of the preceding vowel. The acoustic analysis of /Vm, Vn, Vŋ/ syllables indicate three potential cues: (1) transition, (2) murmur, and (3) final vocalic release. The relative effectiveness of these cues was assessed by removing each in turn from /m, n, ŋ/ spoken after seven different vowels by a male native speaker of English. The syllables were digitized and edited by computer and the different versions of each presented to subjects for identification. The results indicate that not only did the percentage of overall correct responses vary depending on which cue had been removed, but also that the substitution errors fell into well-defined categories. [Work supported by NICHD.]
Fine structure of airfoil tone frequency
Authors: Fink M. R.
Published: October 2005

A method is described for calculating frequency of tone noise radiated by constant-chord airfoils in uniform low-turbulence flow. This noise mechanism is important for small aircraft propellers and helicopter rotors, and for automotive radiator cooling fans. Tones are attributed to a feedback loop between instability waves convected downstream within a laminar boundary layer extending to the trailing edge and sound waves generated at the trailing edge and radiated upstream in the inviscid flow. The upstream extent of the feedback path is the most forward distance at which a laminar fluctuation at the tone frequency is unstable. For small increases of flow velocity, the total number of phase cycles around the feedback loop remains constant and the frequency increases less rapidly than flow velocity, When frequency has increased such that the ratio of chord to half the acoustic wavelength becomes an integer, the number of phase cycles abruptly increases to the largest integer for Which a large-amplitude feedback cycle can occur. The resulting calculated steplike jumps of tone frequency generally match the available data.
Marching techniques for estimating duct attenuation and source pressure profiles
Authors: Baumeister K. J.
Published: October 2005

A numerical method is developed to predict the pressure distribution of a ducted source from farfield pressure measurements. Using an initial value formulation, the Helmholtz wave equation (no steady flow) is solved using explicit marching techniques which can readily be extended to three-dimensional and nonlinear problems. The Von Neumann method is used to develop relationships which describe how sound frequency and grid spacing affect numerical stability. At the present time, stability considerations limit the approach to high-frequency sound. Example calculations for both hard and soft wall ducts compare favorably to known boundary value solutions. In addition, under the assumption that aerodynamic forces which produce sound dominate (negligible reflections), this initial-value approach is successfully used to determine the attenuation of a straight soft wall duct. Compared to conventional finite-difference or finite-element boundary value approaches, the numerical marching technique is orders of magnitude shorter in computation time and can be easily employed in problems involving high-frequency sound.
Prediction of interface wave profiles for a flow-excited cavity resonator
Authors: Elder S. A.
Published: October 2005

Experimental and theoretical results are presented for a wall-mounted cavity in turbulent flow, oscillating at Helmholtz or depth mode resonance. Data for interface waves at the mouth of the cavity, obtained by the CASH method, can be fitted to limiting expressions obtained from linearized instability theory. At typical steady-state amplitudes, the wavelength of the disturbance agrees well with the predictions of Michalke [A. Michalke, J. Fluid Mech. 23, 521–544 (1965)], using an equivalent laminar flow model based on the mean velocity profile. Simple exponential growth of the driven wave does not occur, however, on account of nonlinear effects. Near the leading edge, the interface displacement is a superposition of a traveling wave and a stationary acoustic contribution. For the portion of the profile near the trailing edge, the traveling wave becomes predominant. Theoretical interface profiles have been used successfully in a root-locus solution of the resonant frequency lock-in problem, making it possible to predict Strouhal number and amplitude of cavity oscillation. [Work supported by a GHR contract with the Naval Ship Systems Command, administered by the Naval Ship Research & Development Center, Carderock, MD.]
Differential acoustic bearing as a technique to study internal waves
Authors: Fisher F. H. , Williams R. B.
Published: October 2005

Measurements have been made of the effect of internal waves on acoustic bearings near the island of Hawaii. The research platform FLIP was instrumented with a 30-element vertical thermistor string (∼3-m uniform spacing) and with hydrophone booms at depths of ∼30 and ∼90 m. The mixed layer depth was below 30 m. With a sound source at a depth of ∼30 m and a range of 1.5 nm, the bearing of the sound source was measured with the 30- and 90-m hydrophones. The difference in bearings measured at the two depths is compared to the record of isotherm depths obtained with the thermistor string. The differential acoustic bearing technique is suggested as a means of measuring propagation direction and spatial coherence in the horizontal for short period (3 cph) internal waves. [Research supported by the Office of Naval Research.]
Numerical inverse-scattering studies of ocean bottom interactions
Authors: Greene R. R. , Tappert F. D.
Published: October 2005

A series of computer programs have been developed that solve both the direct and inverse problems for the one-dimensional acoustic wave equation. This “scatter library” is particularly useful for comparing the relative advantages (stability, accuracy, etc.) of various algorithms for solving the inverse-scattering problem. The algorithms included at the present time are (1) solution of the Marchenko equation: (2) the trace formula, a new method developed at the Courant Institute by P. Deift and E. Trubowitz; (3) perturbation techniques, such as those of Kay and Moses, and Bleistein and Cohen. In all cases, the acoustic wave equation is spectrally analyzed and then transformed into the time-independent Schrödinger equation. The inverse transformation is done numerically to recover the acoustic impedance from the plane wave reflection coefficient, or equivalently, from the impulse response function. [Work supported by ONR.]
Strong scattering in the ocean: Feedback (operational) solutions to the wave equation in random media
Authors: Breton II. J. Raymond , Middleton David
Published: October 2005

Operational (feedback) methods are a new method of solving the stochastic wave equation. In the solutions geometrical considerations enters only as a feedforward operator, while the medium enters only as a feedbackward operator. These new methods produce solutions to the wave equation in arbitrary and empirical media. Moreover, from moment analogs the statistics of the propagation process are obtainable. In addition to producing exact solutions to the wave equation in arbitrary media, the solutions illuminate the approximations used in the series solutions and their convergence properties.
Ocean surface duct propagation. I. A simple model for calculation of cross-layer diffraction using an analog-to-quantum-mechanical barrier penetration
Authors: Woodsum Harvey C.
Published: October 2005

The problem of sound diffracting out of an isothermal ocean surface layer or duct is shown to be identical to the quantum mechanical problem of “barrier penetration.” The barrier-penetration factors, calculated using the JWKB approximation, are computed for the normal modes of the duct (which are analogous to the “bound states” of a quantum mechanical system) and these results are then used to calculate the shadow zone field beneath the duct. The duct leakage due to this diffraction is translated into exponential attenuation with range for each normal mode.
Ambient noise measurements in Dabob Bay and the open ocean
Authors: McConnell S. O. , Lilly J. G.
Published: October 2005

Ambient noise measurements have been made at high frequencies (7–40 kHz) to determine the vertical surface radiation pattern and spectral level as a function of environmental conditions. A multibeam acoustic lens mounted on a stable platform was used to perform the measurements. The data exhibited significant differences between the open ocean and Dabob Bay. The surface radiation pattern could be described by sin2θ (θ = grazing angle) dependence in Dabob Bay as compared to a sinθ behavior in the open ocean. The spectral slopes were found to be significantly larger in Dabob Bay as compared to the open ocean results and the Knudsen curves. The spectral level, however, was in general agreement between the two locations. The spectral level was also in agreement with the results of other investigators, particularly the dependence on wind speed and rain rate. [Work supported by the Naval Sea Systems Command under contract N00024-78-C-6018.]
Wind dependence of low-frequency noise off Cape North, Nova Scotia
Authors: Collier A. J.
Published: October 2005

Over the period September 1968–June 1969 ambient noise spectrum measurements were made using a bottom-mounted installation in the Cabot Strait just off the northern tip of Nova Scotia. Several noise-producing mechanisms were identified, including wind-generated noise, ship-produced noise, and noise due to flow past the hydrophone. It was possible to identify and eliminate those data which were contaminated by high flow noise and to a lesser extent to eliminate samples contaminated by nearby shipping. Analysis in two ⅓-octave bands below 10 Hz shows that the spectrum levels between 10 and 4 Hz are wind dependent.
Frequency dependence and detection of individual normal modes in shallow water
Authors: Tindle C. T.
Published: October 2005

A method of extracting a best estimate of the signal carried in an individual normal mode yields good results for a pulsed source. The systematic appearance of higher modes as frequency increases can be examined and indicates strong attenuation of modes near cutoff. Frequency spectra of individual modes are in agreement with theoretical results found from a simple model.
Three-dimensional digital computer spectogram of pathological knee joint noise
Authors: Chu M. L. , Gradisar I. A.
Published: October 2005

Arthritis and other related disorders are, today, the most common nonfatal crippling diseases. In every case these joint diseases involve progressive destruction of the articular cartilage. Previous studies [M. L. Chu, I. A. Gradisar, and M. R. Railey, J. Biomech. 9, 3 (1976)] have shown that the different forms of these diseases have distinctive acoustic signature. Recent development of the three-dimensional spectogram of the noise emitted by the joint during articulation has possible clinical potential for the evaluation of the articular condition of the joint both objectively and noninvasively. With the aid of a three-dimensional spectral history plot, monitoring and localization of the damage on the joint cartilage surface is possible. [Work supported by NIH.]
High-resolution ultrasonic velocity measurements in mammalian tendon with acoustic microscopy
Authors: Goss S. A. , O'Brien W. D.
Published: October 2005

Ultrasonic velocity measurements were made in fresh samples of mammalian tendon at a frequency of 100 MHz using the scanning laser acoustic microscope (SONOMICROSCOPE 100®). This instrument permits the examination of micron regions in tissue for velocity and attenuation variations, with very thin specimens, thus allowing a greater latitude of tissues and organs to be measured. Tendon is of interest since it contains an unusually large amount of collagen (in the range of 50%–95% of the dry weight), a structural protein thought to be important to the echographic visualibility of tissues and pathologies in medical ultrasound. For the first time direct velocity measurements of fresh collagen threads from tendon have been made. Results indicate that ultrasonic velocity is at least 25% higher than in soft tissues, lending support to the view that tendon, as well as collagen, is markedly distinguished ultrasonically from other biological tissues. [This work was supported, in part, by grants from the National Institutes of Health and the National Science Foundation.]
Pulsation threshold in the auditory nerve
Authors: Harris David M. , Dallos Peter
Published: October 2005

Response patterns of single auditory-nerve fibers are compared under two conditions. The first condition is similar to the stimulus condition customarily used to determine pulsation threshold psychophysically. A 100-ms duration signal at a fiber's characteristic frequency (CF) is presented at 10 dB above threshold at a rate of 5/s. A 100-ms duration tonal masker is introduced during the interval between signal pulses, raised in intensity and PST response patterns collected at each masker level. The second condition is the same except that the signal is continuous rather than pulsed. In the pulsed-signal condition when the masker-evoked discharge rate equals the signal-evoked discharge rate, the response pattern resembles the firing pattern to a continuous tone. When the masker-evoked rate exceeds the signal-evoked rate, the response pattern is indistinguishable from the pattern evoked by a continuous signal plus a pulsed masker. For different masker frequencies the results are essentially the same when masker level is expressed relative to the fiber's excitatory response threshold at the frequency of the masking stimulus. It is suggested that “pulsation threshold” is an auditory illusion in which the central processor is presented with ambiguous information and accepts as a “perceptual hypothesis” the more likely possibility that a continuous signal is superimposed on a pulsed masker. Data presented previously on forward masking and unmasking [J. Acoust. Soc. Am. 62, S45–S46 (A) (1977)] will be reviewed and compared to the pulsation threshold data.
Forward masking as a measure of spectral resolution in hearing-impaired listeners
Authors: Wightman Frederic L.
Published: October 2005

Data from masking experiments have long been used to draw inferences about the properties of the mechanisms which mediate auditory spectral resolution or the status of those mechanisms in persons with a hearing impairment. It has recently become apparent that because of rather complex, nonlinear interactions between signal and masker (e.g., that result in distortion products or “suppression”), data from the classical simultaneous-masking experiments must be assumed to reflect the influence of several mechanisms in addition to those which mediate spectral resolution. This problem is particularly acute in experiments with hearing-impaired listeners, because of the possibility that any one of those mechanisms (or none) may be impaired, and because of the great variability in audiometric configuration encountered in this population. We suggest that forward masking may be a more useful way to assess spectral resolution, particularly in hearing-impaired listeners. As evidence for this, forward-masked psychophysical tuning curves obtained from hearing-impaired listeners are quite reasonable in shape (though much broader than normal) and show none of the rather bizarre irregularities observed in simultaneous-masked tuning curves.
An analysis of the effect of masker level on critical bandwidth
Authors: De Gennaro Steven , Colburn H. Steven
Published: October 2005

A simple mathematical model of auditory nerve activity was used to evaluate the increase in critical bandwidth with masker intensity suggested by psychophysical detection experiments. Given the masker spectrum, the model allows calculation of the excitation areas [i.e., the ranges of characteristic (best) frequencies of excited auditory nerve fibers] as a function of intensity. The results of a recent study of detection thresholds for a tone centered in the gap of a notched noise masker [D. L. Weber, J. Acoust. Soc. Am. 62, 124–129 (1977)] were analyzed. For narrow notch widths, the excitation areas completely overlap in the notch region at all intensities. The masking effect is then essentially the same as for a single wide-band masker, and is characterized by a constant signal-to-noise ratio as a function of masker level. At wider notch widths, the excitation areas are separated by a gap that is inversely proportional to masker intensity. This leads to a nonlinear increase in detection threshold with masker intensity. The model thus predicts Weber's findings and supports the contention that critical bandwidth increases with masker intensity. [Work supported by NIH.]
Relationship between auditory frequency selectivity and two-tone suppression
Authors: O'Malley Honor , Feth Lawrence L.
Published: October 2005

This study examined two-tone suppression and auditory frequency selectivity about 3 kHz for the purpose of demonstrating a qualitative relationship between the two. Threshold masking curves and two-tone masking patterns were collected under a quiet and a noise condition for the same normal-hearing listeners using an adaptive 21FC forward-masking procedure. In the noise condition, a narrow-band noise masker, centered one decade down from the probe, was gated on with the tonal masker(s). Kiang and Moxon [J. Acoust. Soc. Am. 55, 620–630 (1974)] have found that low-frequency narrow-band noise serves to decrease the sharpness of electrophysiological tuning curves by affecting only the tip segments. The data for four highly practiced listeners indicate that the gated noise masker was effective in detuning the masking curves and in lessening the magnitude of two-tone suppression. The mutually reflected changes in masking curves and in two-tone suppression as a consequence of the gated noise masker indicate a close relationship between frequency selectivity and suppression: the greater the magnitude of suppression above the center frequency of the masking curve, the sharper the tuning of the masking curve. [Work supported by grants from the National Institutes of Health and Sigma Xi.]
Indices of ear advantage in dichotic listening
Authors: Speaks Charles , Niccum Nancy , Johnson Cynthia , Chargo Steven
Published: October 2005

Repp [J. Acoust. Soc. Am. 62, 720–737 ( 1977)] recently described the statistical properties of several metrics of the ear advantage in dichotic listening tasks: d, L1, (an index of laterality), POE', POC', φ, and e. Repp argued that an acceptable metric should, among other requirements, be independent of performance level. In theory, only e meets this requirement. We will provide an empirical comparison among the metrics and assess their dependence on performance level. Twenty-four listeners received 20 dichotic listening runs of natural stop-vowel syllables. Listeners marked two responses for each of 30 pairs of syllables per run. Intercorrelations among metrics ranged from +0.95 to +0.99, and all metrics were uncorrelated with performance level; correlations ranged from −0.18 to +0.17. This suggests that all six metrics may permit valid comparisons among listeners. The metric d, which is the simple difference between proportions of correct response for the two ears, does have the theoretical advantage of being a multiplicative rescaling of the frequency with which lateralization occurs and the magnitude of lateralization when it occurs. [Supported by PHS NS-12125.]
Detectability of a pulsed tone in the presence of a masker with time-varying interaural correlation
Authors: Grantham D. Wesley , Wightman Frederic L.
Published: October 2005

Detectability of a filtered 4-ms tone burst (500 or 1000 Hz), presented binaurally and phase reversed (Sπ), was measured in the presence of a narrow-band Gaussian noise masker whose interaural correlation varied sinusoidally between +1.0 (N0) and −1.0 (Nπ). Independent variables were the rate of modulation of the masker correlation (fm), and the instantaneous interaural correlation of the masker when the signal was presented. The peak masking-level difference (signal threshold in Nπ versus threshold in N0) was as large as 17 dB with the 500-Hz signal and fm < 1 Hz. The peak MLD with the 1000-Hz signal was smaller (8 dB). No MLD could be obtained with fm > 10 Hz. The function relating the MLD to fm, describes a kind of “attenuation characteristic” of the binaural system. Our data agree with the growing body of evidence that the binaural system is extremely sluggish in responding to dynamic stimuli. Furthermore, in terms of its response to dynamic stimuli, the binaural system appears to behave similarly in the different spectral regions tested.
Processing of temporal patterns by split brain patients
Authors: Musiek Frank E. , Pinheiro Marilyn , Wilson Donald
Published: October 2005

Three normal-hearing right-handed patients, who underwent complete section of the corpus callosum because of medically uncontrollable seizures, were tested on auditory tone patterns. The pattern stimuli were composed of three 1000-Hz tone bursts with two different intensities (ΔI = 7 dB) or three tone bursts of two different frequencies (high = 1222 Hz, low = 880 Hz). The duration of the intensity patterns was 250 ms while the duration of the frequency patterns was 150 ms. Interstimulus interval was 200 ms for all patterns. A total of 30 intensity and 30 frequency patterns were presented through earphones at a 40-dB sensation level to each ear of the subjects. Only one of the patients was tested preoperatively while all three were tested postoperatively. The one patient preoperatively performed at a near normal level for pattern perception whereas the three patients tested postoperatively performed at a level of chance or slightly better on both auditory pattern tests. Based on these results, it is hypothesized that the verbal response to auditory pattern perception depends on interhemispheric processing. More specifically, the contour of the pattern is recognized in the right hemisphere and the verbal response sequenced in the speech-dominant left hemisphere.
Where does the vocal tract end?
Authors: Ladefoged Peter , Wright James , Linker Wendy
Published: October 2005

During rounded vowels the outer end of the vocal tract may be modeled as an ellipse in the plane perpendicular to the midline. But in other vowels the termination of the vocal tract has a more complex shape because the corners of the lips are not in the same plane as the opening in the midline. in order to investigate appropriate ways of modeling lip actions, three trained subjects were recorded and photographed while saying pairs of vowels such as [i, y; e, ø; Ɯ, u]. In saying each pair subjects took care to hold the tongue position steady and to move only the lips. For each of the rounded vowels a computer model was set up with the observed lip opening and the vocal tract shape that produced the best match to the observed formant frequencies. With this vocal tract shape maintained, the lip opening was then set to that observed in the corresponding unrounded vowel. By varying the distance of the lip opening from the glottis, a program found the best acoustic match to the unrounded vowel. The results indicate the way in which the apparent location of the termination of the vocal tract varies with lip opening.
Automatic identification of phonetic features based on x-ray pellet data
Authors: Nelson W. L. , Miller J. E. , Macchi M. J.
Published: October 2005

A large body of data on the movements of the tongue, lips, mandible, and velum during normal speech has been gathered using an x-ray microbeam system which tracks metal pellets placed on these articulators [Fujimura, Miller, and Kiritani, J. Acoust. Soc. Am. 60, S64(A) (1976)]. The purpose of this study is to automatically match articulatory features derived from the pellet data and acoustic features derived from the speech waveform for an utterance with phonetic features given by a transcription of the utterance. The articulatory features are defined by classifying the position and velocity of the pellets into categories of articulatory dynamics. The acoustic features are defined by classifying the acoustic signal into voiced, unvoiced, silence segments [Atal and Rabiner, IEEE Trans. Acoust. Speech Signal Process. ASSP-22 (1974)]. The phonetic features are traditional qualitative features based on an impressionistic transcription. The three types of features are automatically aligned in the time domain, thus establishing correspondence between pellet data and abstract linguistic analysis. This correspondence allows automatic sorting and analysis to determine the significant articulatory gestures which characterize particular phonetic features.
Some interesting things you can do with your tongue
Authors: Porter R. J. , Lubker J.
Published: October 2005

The tongue assumes, with speed and accuracy, a variety of positions during speech. In order to do so, its control mechanisms presumably possess detailed knowledge of the relation between muscle action and tongue position. Although the general nature of such knowledge may be inferred from the behavior of the tongue during speech, we wondered if the tongue's capabilities might be most directly explored by requiring subjects to produce arbitrary tongue positions in nonspeech tasks of varying complexity. A custom-built device required subjects to move to a light rod into various target positions with the tongue tip. Preliminary results reveal a remarkably high degree of skill, even for a complex “transposition of interval” task. The results suggest that the sensory information regarding tongue position is essentially linear and that in spite of differences in degree of muscle activity for different degrees of extension, the control mechanisms can produce a nearly linear continuum of positions. [Supported by Fulbright-Hays Fellowship and Department of Phonetics.]
Studies of apraxic speech production
Authors: Freeman Frances J. , Sands Elaine S. , Harris Katherine S. , Sweet Susan G.
Published: October 2005

A series of five studies of apraxic speakers generated the following conclusions: (1) The major residual errors for an apraxic with ten years of therapy appeared to result from poor temporal coordination of expiration, vocal fold adduction, and articulatory gesture. (2) VOTs for this patient differed markedly from those of normals, and related to perceived voicing errors for stops. (3) VOTs for four other apraxic speakers were also abnormal. (4) Therapy directed toward teaching the first patient to produce more appropriate voice onset times succeeded in establishing two discreet categories of stops, but VOTs still differed from those of normals and lacked “natural quality.” (5) Lack of success in teaching the patient to produce normal stops may result from the categorical perception of clinicians providing feedback for modification. Results of these studies have implications relating to (1) the nature of the apraxic disorder, (2) use of acoustic analysis procedures for diagnosis and management of speech production disorders, (3) limitations of clinician perception in providing feedback for modification of in-category (distorted) phoneme production errors. [This work was supported in part by NIDR Grant DE-01774.]
New results in auditorium acoustics at Göttingen
Authors: Schroeder Manfred R.
Published: October 2005

Impulse responses, recorded in actual rooms, are digitally modified (to yield longer or shorter reverberation times, more or fewer side echoes, etc.) in order to study the subjective effects of selected physical changes. In these and earlier tests, “binaural dissimilarity” emerged as an important parameter to characterize subjective preference of concert halls. Implications of these results for better concert hall ceiling shapes are discussed. New surface structures, for side walls and ceilings, to realize high sound diffusion over broad frequency bands are being developed, both for reverberation chamber and concert hall use. Work on measuring auditoriums during actual performances (with pseudorandom noise below the masked threshold of hearing) is continuing.
Adjustable acoustics and the “single-” or multipurpose hall: A survey of techniques and an evaluation of owner/user responses regarding effectiveness of adjustable acoustics systems
Authors: Kirkegaard R. Lawrence
Published: October 2005

An imaginative variety of techniques has been used to “tune” performing spaces to accommodate more appropriately the broad range of performance types, ensemble sizes and characteristics, and audience capacities. Clearly some techniques are more effective than others. This paper illustrates many of the techniques and reports on a retrospective survey of owner/user experiences regarding their use, misuse, or nonuse thereof.
Realistic electroacoustic musical tone radiation in rooms
Authors: Martin Daniel W.
Published: October 2005

The size, shape, and distribution of radiating surfaces of musical instruments, and their orientation and location relative to the surfaces of their typical performance room environment, contribute quite significantly to the overall musical impressions received by both the performers and the listeners. When these same musical impressions are to be produced by electroacoustic means the same parameters are pertinent for a fully realistic result. Diversity among the types of musical instruments in their acoustical radiation characteristics makes unconventional electroacoustic systems and installations necessary for producing conventional musical sounds. Examples will be given.
Phased array ultrasound imaging of the heart
Authors: Thurstone Fredrick L.
Published: October 2005

Pulse-echo ultrasound has been widely used for investigating the status and function of the heart. Recently, a number of systems have been developed which produce real-time tomographic images of heart structures. Many of these employ either a switched array of transducers or a phased array for beam steering. The development of such phased array systems, their capabilities, and limitations will be the subject of this presentation. As in all pulse-echo ultrasound used for medical diagnosis, this imaging technique is basically a diffraction-limited process. There are additional imaging constraints imposed by the inhomogeneity of the tissue structures under investigation. These include reverberation effects, aberration effects produced by varying propagation velocity, and amplitude variations due to varying absorption. Still other constraints are imposed by technical limitations on the ultrasound transducer elements themselves. These include the compromise between sensitivity and bandwidth, the directional character of such elements, and other factors. The development of a practical cardiac imaging system together with an on-line image-processing facility will be presented.
Design of a variable-aperture phased array beamformer for use in echocardiography
Authors: Crenshaw E. G. , Ishimaru K. , Miller N. B. , Lawther J. M.
Published: October 2005

A beamformer for evaluation of dynamic aperture control to maximize lateral resolution of an ultrasonic phased array is under development at The Applied Research Laboratory of The Pennsylvania State University. For echocardiographic applications, the beamformer offers the advantages of fast scanning with good lateral resolution at all ranges. Techniques for improving lateral resolution at unlimited depth of field over that obtainable by a fixed focus system include the farfield variable aperture and previously reported dynamic focusing approaches. The relative performance limits and the effects of these techniques on beam-former complexity are compared. An electronic beamformer configuration for implementing the less complex variable aperture approach is described. The ultrasonic array and packaging concepts are presented along with acoustic performance data relating to the individual array elements. Measurements of damping and cross coupling and analyses of predicted performance have been made and are included. Results from computer models of the beamformer and array are also presented which compare the patterns obtained by (1) multiplicative pattern analysis, (2) taking into account the effect of different element patterns, and (3) varying the size of the element. [This work was supported in part by NIH grant R01HL20872-02.]
Scattering of elastic waves by a resonating fluid-filled cylindrical cavity
Authors: Haug A. J. , Solomon S. G. , Überall H.
Published: October 2005

Resonant excitation of a fluid-filled cylindrical cavity in an elastic medium by an incident compressional wave is investigated on the basis of resonance theory of nuclear scattering [G. Breit and E. P. Wigner, Phys. Rev. 49, 519 (1936)]. It is shown that the scattering amplitude consists of a series of narrow resonances superimposed upon, and interfering with, a broad background that corresponds to the scattering from an empty cavity. The resonances may be analyzed in a most enlightening fashion by studying them separately in each partial wave of the normal-mode series. They are seen to correspond to excitations of the eigenvibrations of the cavity fluid caused by a phase match of “creeping waves,” similar to the “Regge poles” of nuclear physics. This paper is part of a series which investigates the excitation of target resonances in the scattering of acoustic and elastic waves using the theory of nuclear resonances. [H. Überall was supported by the Office of Naval Research, Code 421.]
Scattering of dilatational waves incident on a resonating fluid-filled spherical cavity inside a sound-absorbing material
Authors: Gaunaurd G. , Überall H
Published: October 2005

To further understand the internal sound-absorption mechanism in viscoelastic materials containing gas-filled cavities, we analyze the scattering of p waves incident upon one such spherical cavity. [Numerous findings have emerged from the study of this model, some of which we have both presented elsewhere (i.e., IUTAM Symp. Modern Problems on Elastic Wave Propagation, Northwestern U., Evanston, IL, Sept. 1977).] We continue to use an approach familiar in nuclear scattering theory (Breit-Wigner relations) but novel in acoustics, to express the scattering amplitudes (or the partial waves contained in them, fnps and fnpp, with and without mode conversion, respectively) in a form exhibiting their dependence on two interacting contributions. One is the broad background of an ideally soft cavity, the other the superimposed narrow spikes due to resonances excited inside the cavity fluid. The waves penetrate into the filler fluid only at these resonances, while at all other frequencies the cavity appears impenetrable. We show that the interaction of “background and resonances” is the cause of the wildly fluctuating character of the amplitudes (or cross section), and we compute and display the two contributions before (separate) and after (combined) the interaction, for various material combinations and absorption levels. [H. Überall was supported by ONR, Code 421.]
Forced oscillations of nonspherical bubbles
Authors: Hsieh D. Y.
Published: October 2005

The oscillation of a gas bubble in liquid under externally applied sinusoidal pressure field is studied. When the applied pressure amplitude is small and the forcing frequency is not in the neighborhood of the resonance frequency of the bubble, the familiar linear results are obtained. When the applied amplitude is not small there is a tendency to generate both the subharmonic oscillations of the spherical mode and the surface waves on the bubble. The theoretical study is carried out mainly by the variational method. Experimental implication of the theoretical results is also discussed.
Ultrasonic absorption in binary solutions of pyridine with tert-butyl alcohol and phenol
Authors: Gupta P. K. , Stumpf F. B.
Published: October 2005

Measurements of the ultrasonic absorption (α/f2) versus concentration have been made for binary solutions of pyridine with tert-butyl alcohol and phenol. The frequency used was 19.5 MHz and the temperature was 30 °C. Qualitative explanations are given for the behavior of α/f2 versus concentration in each case. One mechanism responsible for the behavior mentioned seems to be the deexcitation of the vibrational states of one molecule by a different molecule, e.g., pyridine by tert-butyl alcohol or by phenol.
The effect of sensorineural hearing loss on acoustic stapedius reflex growth functions
Authors: Silman Shlomo , Popelka Gerald R. , Miller M. H. , Gelfand Stanley A.
Published: October 2005

The growth function of the acoustic stapedius reflex was measured in subjects with normal hearing and sensorineural hearing loss of cochlear origin. The effects of age and magnitude of hearing loss were controlled. Activating stimuli were 500-, 1000-, and 2000-Hz tones and broadband noise. Stapedius muscle activity was inferred from acoustic impedance measures in the contralateral ear. The mean growth functions were essentially linear in log-log plots with the rate of growth equal for the two groups. The mean growth function for the noise signal was curvilinear for the normal-hearing group and linear for the hearing-loss group. Comparison of slope functions derived from the fitted data indicated that the normal rate of reflex growth for the noise signal, over a limited range above reflex threshold, increases in ears with cochlear lesions. For higher-level noise signals, however, the normal rate of reflex growth is unchanged by these lesions. The effect of a cochlear lesion on the input-output function of the cochlea for both tonal and noise stimuli is to maintain the rate of reflex growth but shift the function along the intensity axis by an amount equal to the shift in reflex threshold.