bluuebunny/crossref_metadata_2025 huggingface dataset:
Transient latency in masking level difference
Authors: Kado Hisashi , Chiba Shigeru , Ohta Kohzo , Miura Hajime , Fukumoto Masaaki
Published: October 2005

The threshold was measured for a signal S0 of 100 ms long at various timing points in a noise burst by a sequential searching procedure. The noise burst lasted from t = −1000 ms to t = 1000 ms. At t = 0 ms, the noise was changed from N0 to Nπ. The threshold was expected to decrease just after t = 0 ms. The latency was defined as a time constant of the decreasing characteristic of the threshold. In the case of S0 being a pure tone, the results showed artifacts at the N0 area and it was hard to define the latency. In the case of S0 being a vowel (female /a/, /i/ and male /i/), the latency was about 100 ms when subjects were required to identify the signal, and the latency was about 10 ms when subjects were required to detect the signal. The equalization and cancellation model could not explain the 10-ms latency, because it is not reasonable to assume such fast feedback in the model. It is speculated that both the addition and subtraction of dichotic and/or diotic signals are sent to a higher level of the hearing system in such fast latency.
Discrimination of the orientation of a natural sound source
Authors: Zerne Pamela , Perrott David , Cote John , Lira Charles
Published: October 2005

The ability to discriminate the direction that a speaking individual is facing (i.e., toward, away, to the right, or to the left relative to the listener) was explored in a free-field environment under monaural and binaural listening conditions with relative distances ranging between 1.5–12.0 m. All sessions were conducted under double-blind conditions. Performance under binaural conditions clearly exceeded chance at all orientations and distances. The ability to resolve that the speaker was facing right or left was significantly impaired when binaural cues were eliminated. This surprising ability to resolve the relative orientation of a human speaker in the right-left dimension cannot readily be explained by current theories of auditory spatial processes. [Work supported by NSF and NIH.]
Simultaneous modeling of EGG, PGG, and glottal flow
Authors: Cranen B.
Published: October 2005

For obtaining insight into basic aspects of voice quality, an adequate parametrization of the voice source is mandatory. Theoretical studies have shown that changes of the glottal geometry in the direction of flow are an essential prerequisite for self-oscillation of the vocal folds. Thus it is attractive to use stylized glottal shapes as a basis for voice source parametrization, and try to extract the geometry parameters (semi-) automatically from indirect measurements like the electroglottogram (EGG) and photoglottogram (PGG). Titze [J. Acoust. Soc. Am. 75, 570–580 (1984)] presented a model with which he simulated simultaneous measurements of PGG and EGG. It is thought that EGG and PGG are not sufficient for inferring all relevant aspects of glottal geometry. In this paper, it is shown that glottal flow supplies additional information that can be used to impose extra restrictions on the model parameters. Simulations show that when simultaneously modeling EGG, PGG, and glottal flow, it is crucial to assume that the opening of the vocal folds occurs more gently than the closing. Implications of this finding for the description of vocal fold movements in modeling EGG and PGG are discussed.
The fundamental frequency-subglottal pressure ratio in speech
Authors: Boves Louis , Strik Helmer
Published: October 2005

It is known that subglottal pressure PS is a major factor in the control of fundamental frequency (F0) in speech. Yet, the details of this relation remain unclear. Estimates of the dF0dPs ratio obtained from speech and special phonation tasks yield values between 5 and 13 Hz/cm aq. ” “Push-in-the-stomach” experiments, on the other hand, tend toward values of 3–5 Hz/cm aq. The experiments discussed here aim at resolving this discrepancy. Simultaneous registrations have been made of subglottal and oral pressure, laryngeal EMG, EGG, and lung volume during a number of phonation tasks. Present results suggest that in the push-in-the-stomach experiments F0 lags PS to such an extent that the full effect of changes in PS is not attained before the subject starts compensating (in one way or another) for the disturbance in PS. Thus these experiments tend to underestimate the dF0/dPs ratio in undisturbed phonation tasks. Implications for the explanation of declination in speech will be discussed. [Research supported by the Foundation for Linguistics, funded by N. W. O.]
Control of fundamental frequency and intensity in running speech
Authors: Strik Helmer , Boves Louis
Published: October 2005

This study explores the control of fundamental frequency (F0) and intensity level (IL) in running speech. To that end, simultaneous recordings of speech, electroglottogram, lung volume, sub- and supraglottal pressure (Psb and Psp), and EMG activity of cricothyroid, vocalis, and sternohyoid were obtained for three Dutch subjects. After preprocessing, the data were subjected to a stepwise multiple regression analysis. Here, F0 and IL were used as dependent variables. Results show that the pressure signals are the most important factors in the control of both F0 and IL. However, results are dependent on the method of analysis used. On sentence level, Psb appears to be the most important mechanism controlling F0, while on word level Psp and muscle activity become more important. For IL, on sentence level Psb and Psp seem to contribute equally to its control via transglottal pressure. But on the level of individual words Psp alone explains approximately 80% of the total variance of IL. [Research supported by the Foundation of Linguistics, funded by N. W. O.]
Acoustic description of rehearsal effects on the voice
Authors: Ingrisano Dennis , Chicouris Cynthia
Published: October 2005

The vocal characteristics of six amateur singers were recorded longitudinally as the performers prepared for a Carnegie debut. The demands of rehearsals increased as the singers neared the performance date. Recordings were taken before and after rehearsal for a 3-month time period. Voice samples derived from reading material and sustained phonation were analyzed for frequency and amplitude perturbation; noise components associated with vocal use were also estimated. Results are discussed with reference to vocal fold overuse in this subject group and in previously reported literature [N. Punt, J. Laryngol. 97, 13–17 (1983); P. Ward and G. Berci, Laryngoscope 92, 13–77–1382 (1982)].
Control of Japanese pitch accent by electrolarynx talkers
Authors: Kobayashi Noriko
Published: October 2005

Japanese word accent is known to be characterized by changes in vocal pitch. For speech with an electrolarynx of transcervical type, production of pitch accent is a difficult speech task, since most electrolarynges are not designed to facilitate quick pitch changes. However, skilled Japanese electrolarynx talkers manage to produce contrasts of word accent to a certain extent. This paper reports some perceptual cues and their effects for word accent produced by Japanese electrolarynx talkers. Subjects are four male laryngectomees who use electrolarynges with good speech intelligibility. Audio recordings were made during multiple repetitions of ten types of word pairs. Each pair consisted of two-mora words with identical phoneme sequences and contrasting accent types. Acoustic analyses revealed that the talkers successfully produced accent contrasts mainly by changing the segmental duration. Discussion will be made on some speech strategies that are not used by normal talkers for producing major perceptual cues but which are sometimes effective for the speech handicapped population for whom normal cues are not available.
Noise measurements of adult men's and women's voices
Authors: Nittrouer Susan , McGowan Richard S. , Beehler Donna
Published: October 2005

Two algorithms that were designed to detect noise in voiced speech were applied to the middle portion of vowels spoken by men and women in running speech. It was found that the women had as high a signal-to-noise ratio as the men, indicating that the women did not produce more turbulence noise than the men. Also, the ratio of the amplitude of the fundamental to first harmonic (the H1-H2 ratio) was found to be higher for the women than the men. This ratio is a measure of breathiness, which is sensitive to the abruptness of vocal fold closure [C. Bickley, MIT Working Papers, Vol. 1]. The evidence here indicates that turbulence noise is independent of the H1-H2 ratio and the abruptness of fold closure to some degree. The absolute jitter was found to decrease with frequency, corroborating the findings of others. Comparisons for the effect of time of day showed that jitter increased with time of day. [Work supported by NIH grants to Boys Town National Institute and NIH Grants NS-13870, NS-13617, and HD-1994 to Haskins Laboratories.]
Analysis of hoarse voice applied to the diagnosis of laryngeal disease
Authors: Koizumi Takuya , Taniguchi Shuji
Published: October 2005

A hoarse voice seems to have some acoustic properties that are associated with, and thus serve to indicate, the cause of hoarseness, that is, a pathological condition of the larynx. Hence it appears to be possible to determine, to some extent, the nature of laryngeal disease through an analysis of the hoarse voice caused by it. This work is concerned with the diagnosis of laryngeal disease by a hoarse voice analysis. This procedure of diagnosis is based on techniques of feature extraction and categorization in pattern recognition. Given samples of hoarse voices, a set of characteristic features is extracted from the samples by applying an appropriate analysis to them. The observed features expressed in the form of pattern points in a multidimensional pattern space are then classified into several different pattern classes, each of which represents a laryngeal disease. Among several methods of analysis that have been tried, two specific methods including ordinary spectral analysis by FFT have been found to be useful in this particular classification, or diagnosis, scheme.
Release mechanisms for stop and nasal consonants
Authors: Stevens Kenneth N.
Published: October 2005

Theoretical models have been developed to account for the rapidly changing acoustic events at the release of stop and nasal consonants with different places of articulation. The model for stop consonants predicts the level and spectrum of the initial transient, the burst of noise, aspiration noise, and formant transitions, and shows differences in the contribution of each of these components over the initial 10–20 ms for labial, alveolar, and velar places of articulation. For nasal consonants, the abrupt change in spectrum at the release can be explained by rapid movement of the zeros of the transfer function of the oral-nasal system, and by a somewhat slower movement of the poles. The pattern of movement of the zeros and hence the nature of the spectrum change depend on the consonantal place of articulation. Spectra data for spoken stop and nasal consonants, obtained with fine time resolution, show general agreement with the theoretical predictions, although the lack of quantitative data on dynamic and kinematic articulatory parameters makes detailed comparison difficult. [Work supported in part by a grant from NINCDS.]
A cross-linguistic contrast in consonant and vowel timing
Authors: Smith Caroline L.
Published: October 2005

Two opposing explanations of the timing of consonants and vowels are that (1) they are timed relative to each other, or (2) vowels are produced in a continuous rhythm with consonants superimposed on them [Fowler, J. Exp. Psychol. 112, 386–412 (1983)]. Languages with different temporal properties, such as Japanese, a mora-timed language, and Italian, a syllable-timed language, might be expected to exemplify these different relationships. Speakers of each of these languages were recorded producing pairs of disyllabic words with medial consonants of contrasting length (single or geminate). Evidence from measures of acoustic duration and vowel-to-vowel coarticulation, shown by contextual changes in F2, suggest that Fowler's model (2) predicts the timing patterns found in Italian, while the other model (1) predicts the behavior of Japanese. [Work supported by NSF.]
Wave-vector filtering of holographic data on point-driven cylinders
Authors: Grosh Karl , Williams Earl G.
Published: October 2005

Generalized nearfield acoustical holography was used to provide the radial velocity ν(z,φ,ω) at over 8000 locations on a complete cylindrical surface tangent to a point-driven, submerged capped cylinder. Because of circumferential periodicity, circumferential waves can be extracted by the use of simple FFT methods, yielding ν(z,n,ω)einφ, where n is the circumferential wavenumber. To obtain an axial decomposition of the waves, the FFT fails due to insufficient resolution and spectral leakage. Instead a high-resolution method is used, the extended Prony method. Key to the success of this method is the use of singular value decomposition to estimate the number of waves (model order) present at a particular frequency and value of n. With the model-order estimation, the Prony method provides accurate location of the poles corresponding to the desired wavenumbers. An iterative scheme is used to refine the whole process. The resulting waves can be related to the fluid-loaded modes of the driven structure.
Spectral parametrization of wave scattering from a rigid aperture coupled enclosure with interior loading
Authors: Felsen L. B. , Vecchi G.
Published: October 2005

Wave interaction with complex structural environments can be analyzed by regarding the overall response as the response from coupled subsystems. The decomposition into subsystems is wavenumber-scale dependent, and the “best” classification involves weak coupling between subsystems but strong coupling of wave types within a subsystem. How to effect the classification is illustrated here for a cylindrical thin smoothly convex rigid shell, which grants access to an enclosed cylindrical convex rigid interior load via a narrow-slit aperture. The geometry suggests a parametrization of exterior wave phenomena by geometrically reflected, slit diffracted, and surface guided creeping waves, and of interior wave phenomena by guided local modes in the nonuniform waveguide formed by the region between the shell and interior boundary. The slit produces coupling among the exterior wave types and among the interior wave types, as well as between the exterior and interior. These couplings cause spatial wavenumber conversions from trapped, to radiating, etc. A system of state vectors, propagation matrices, and coupling matrices renders the overall description self-consistent, and permits the development of reduced forms by loading a significant (for example, resonant) subsystem with nonresonant remainders. The dynamics of the parametrization is illustrated by considering the numerical example of plane wave scattering as a function of aspect and frequency when the interior and exterior boundaries are eccentric circular cylinders. [Work supported by ONR and David Taylor NRDC.]
Examples of two wavenumber spectra in nonhomogeneous one-dimensional structures
Authors: Kennedy Robert M. , Strawderman Wayne A.
Published: October 2005

Structures of interest to hydroacoustic research frequently have spatially varying properties that cause the field variable to be statistically nonhomogeneous. Two wavenumber spectra of one-dimensional nonhomogeneous fields have been defined [W. A. Strawderman, J. Acoust. Soc. Am. Suppl. 1 80, S15 (1986)], but there exists little experience in interpreting these spectra. This paper presents a first look at the two wavenumber spectra of various theoretical and measured examples of nonhomogeneous fields. The examples are chosen to form a progression of two wavenumber spectra from simple canonical forms of exponentially damped traveling waves to more complex measured nonhomogeneous fields on axisymmetric periodic structures. The desired two wavenumber spectra are obtained from calculated or measured cross-specral density matrices by use of an efficient algorithm. A comparison of the spectra of both the canonical and measured fields displays a common structure observed in both. One and two wavenumber spectra of measured data are compared to illustrate the potential simplification and interpretive role of two wavenumber spectra.
Speeding up the IFD model by high-order numerical methods
Authors: Lee Ding , Saied Faisal
Published: October 2005

The implicit finite difference (IFD) model implements an IFD scheme of the Crank-Nicolson type to accurately solve a wide angle wave equation. To maintain the desired accuracy, in some cases, the IFD requires small step sizes in both depth and range directions, which increases the computation time. A number of high-order finite difference methods for solving equations of the Schrödinger type have been developed. These high-order methods are not only accurate but also allow the use of larger step sizes in both depth and range directions. A fourth-order implicit finite scheme (IFD4) is used to solve the parabolic wave equation as a demonstration of the speed advantage. While accuracy is maintained, the IFD4 offers much faster speed than the Crank-Nicolson IFD model. Numerical results will be presented to show the savings in computing time achieved by these methods. Theoretical developments and computational aspects will be discussed. [Work supported jointly by NUSC and ONR.]
Parametric measurement of sound source directivity: Effect of the source nearfield
Authors: Sample John D.
Published: October 2005

The suggested use of a parametric receiving array to measure the directivity of a distributed sound source in a multipath environment is complicated by the disparity between the beam patterns of the difference frequency and linear sound fields. This disparity can be understood by considering the interaction volume as two independent sources: one representing the volume in the nearfield of the source and the other representing the farfield volume. The interaction volume in the farfield of the source has the same directivity as the linear radiation of the source, but the measured difference frequency directivity is contaminated by the contribution from the nearfield volume. The nature of the contamination in the case of a Gaussian-shaded pump interacting with an approximation of a circular piston is analyzed using a previously developed computer model. The nature of the differences between linear and difference frequency directivities is described and the dependence on range and pump location is studied. The cause of these differences is identified as difference frequency sound produced in the nearfield.
Nonlinear interaction of collinear sound beams in the nearfield
Authors: Kamakura Tomoo , Kumamoto Yoshiro
Published: October 2005

Many spectral components generated by nonlinear interaction of two collinear sound beams can be calculated using Aanonsen's method [J. Acoust. Soc. Am. 75, 749–768 (1984)]. Aanonsen's initial pressure condition is extended to the case where a radiating wave at the source consists of two adjacent harmonies. Numerical computations are performed for a nearfield of a Gaussian source in air. Propagation curves and beam patterns of the primary and secondary waves are given for various source levels. When the source intensity is increased, the higher frequency primary wave fades out more than the lower frequency wave, and the harmonics of the difference frequency increase. Parametric generation of the difference frequency and its second harmonic component for AM excitation are also considered.
Propagation of the difference frequency wave generated by a truncated parametric array through a water-sediment interface
Authors: Wensen Liu , Zhenxia Xu
Published: October 2005

T. G. Muir et al. observed experimentally that the maximum of the received sound pressure in the sediment insonified by a parametric array departed significantly from the prediction of Snell's law. The wave fronts penetrated more steeply into the sediment and the attenuation with depth was less than predicted by plane-wave theory at the postcritical incidence. It was found that, due to the variation of the length of the parametric array and the variation of the attenuation in the sediment, the maximum of the received sound pressure occurs at the line-of-sight between the projector and the hydrophone. It has been proved both theoretically and experimentally that Snell's law is still valid when the length of the parametric array and the attenuation in the sediment are kept constant. Due to the contribution of the secondary sources close to the boundary, the postcritical penetration of the parametric array can be deeper. The lateral wave should be considered at the postcritical incidence.
Acoustic wave propagation employing Gaussian wave packets
Authors: Ryan F. J.
Published: October 2005

Recently, there has been much interest in using Gaussian beam methods to solve wave propagation problems in spatially inhomogeneous media. A new full-wave propagation technique, multiple Gaussian wave packets (MGWP), will be described, which combines some features of Gaussian beam methods and the split-step PE algorithm. Briefly, the MGWP technique consists of expanding the initial wave field at some starting range into a series of complex Gaussian wave packets and then allowing the wave packets to evolve with range. Each wave packet has the functional form of a Gaussian with complex parameters that control the phase-space distribution of the wave packet. The range evolution of the Gaussian parameters is governed by a Schrödinger equation and is exact for refrative index profiles that are quadratic. Comparisons of the MGWP method with a normal mode propagation model will be shown. [Work supported by NOSC IR.]
Benchmarking range-dependent, ray-tracing codes in non-Cartesian coordinates
Authors: Tan Sze M. , Bold Gary E. J.
Published: October 2005

The problem of validating computer codes for numerical ray tracing in range-dependent, sound-speed profiles will be discussed. To find accurate travel times for eigenray computation, one must obtain precise solutions of the ray equations parametrized by time. A method for finding nontrivial sound-speed variations based on conformal transformations is described that allows analytic solutions from simpler ray-tracing problems to be used for computing ray paths through the resulting range-varying medium. Besides its application to validating computer codes, the method can be used to convert a ray-tracing or eigenray-finding problem originally formulated in terms of a circular or elliptical coordinate system into an associated problem on a Cartesian coordinate system. Sound-speed fields specified on the natural grid for the non-Cartesian system map directly onto the Cartesian grid, allowing the use of more computationally efficient Cartesian ray-tracing algorithms. Travel times are not affected by the transformation. Hence, the method is particularly suited to predicting arrival times associated with eigenrays. Illustrative ray traces and results will be shown.
Three-dimensional acoustic mode propagation in the Gulf Stream
Authors: Chiu Ching-Sang , Ehret Laura L.
Published: October 2005

Based on the coupled mode theory, an efficient 3-D (i.e., three-dimensional) acoustic code for the computation of sound propagation through mesoscale ocean features was developed. The technique numerically integrates a set of first-order differential equations governing the complex envelopes that modulate, mode by mode, the adiabatic mode solution. Sensitivity studies showed that the slowly varying envelopes associated with the forward propagating components can be computed accurately using a step size much longer than the acoustic wavelength. Calculations further showed that the backscattered field is negligible even in frontal systems having extremely large sound-speed gradients. Gulf Stream sound-speed fields generated by a Harvard University ocean forecast model were used to investigate the three-dimensional environmental effects on sound propagation, both cross and along stream. In order to examine the significance of horizontal sound diffraction, the 3-D solution was compared to the N by 2-D solution. Comparison between the 3-D coupled mode and adiabatic approximation calculations was also made in an effort to quantify the validity of the adiabatic approximation.
Interactive 3-D canonical acoustic modeling
Authors: Nghiem-Phu Lan , Daubin Scott C. , Tappert Frederick D.
Published: October 2005

There is often the question of whether the behavior of acoustic signals can be predicted in the complex and changing ocean environment. Our deplorable state of prediction is either blamed on limitations of acoustic models, or on the usually incomplete knowledge of the ocean environment, or on both. Despite the fact that efforts are being made to provide the critical links between the fields of oceanography and acoustics, still lacking is a comprehensive strategy to measure or predict oceanic features in order to improve our acoustical predicting capability. In a companion paper, a generalized canonical sound-speed (GENCASS) numerical environmental model is discussed. This GENCASS model is implemented in the Pesogen computer system [J. Acoust. Soc. Am. Suppl. 1 75, S26 (1984)] for illustration of the feasibility of using such a technique in an interactive acoustic modeling machine to better understand the interrelationships between complicated environmental conditions and their acoustical consequences. The interactive nature of this process allows rapid understanding of the database requirements, in preparation for setting environmental knowledge bounds toward better predicting capability. Examples will be shown to demonstrate the realistic nature of the canonical oceans.
The impact of a pH-dependent attenuation formula on previous estimates of surface loss and bottom loss
Authors: Browning David G. , Scheifele Peter M. , Mellen Robert H.
Published: October 2005

Determination if surface loss and bottom loss from at-sea measurements requires the assumption of a propagation loss model. In most cases, this has consisted of a simple spreading loss (spherical and cylindrical) model plus attenuation. The recent development of a pH-dependent attenutation formula will have an impact on previously reported values of loss that were obtained using the old Marsh-Schulkin or Thorp attentuation formulas. Due to the depth dependence of a typical pH profile, this impact will depend on the configuration of the measurement in the water column. For example, previous values of surface loss that were obtained from propagation loss measurements in a surface duct (where the pH and, hence, the attenuation have the highest values) will be too high since the previously assumed value of attenuation was too low. Estimates are made of the possible impact on some of the most widely used formulas. [Work supported by NUSC.]
Evaluation of Japanese speech intelligibility for the sound system of an auditorium by STI
Authors: Oguchi Keiji , Nagata Minoru
Published: October 2005

Subjective hearing tests and STI measurements were carried out in a church and in six auditoriums. The relationship between the intelligibility and the directivity of the loudspeakers was studied for Japanese speech. In the church, the experiment was performed with four types of loudspeakers having different radiation directivity. At the point of 4*Dc (Dc is the critical distance) from the loudspeaker, STI was about 50%, and the intelligibility was found to be “fair.” STI measurements were successively carried out in six auditoriums with clustered loudspeaker systems designed to cover the audience area within 4* Dc. The results showed almost the same relationship between the STI and the ALcons given by T. Houtgast even for Japanese speech. Finally, the validity limits of STI as parameter for evaluating the performance of sound systems in auditoriums is discussed.
Vowel durational characteristics daring simultaneous communication
Authors: Whitehead Robert L. , Whitehead Brenda H.
Published: October 2005

The purpose of this investigation was to study vowel durations during speech produced simultaneously with sign language and fingerspelling and to determine whether final consonant influences on vowel durations, which occur naturally in speech, also occur in speech produced during simultaneous communication. Vowel durations were obtained for the vowels /ɑ/, /ɪ/, and /æ/, which were embedded in CVC words in which the final consonant was systematically varied. All CVCs met the criteria of having a common sign and of being phonetically and orthographically correlated. The CVCs were embedded in a carrier phrase and were uttered by ten normally hearing speakers fluent in sign language, under conditions of: speech, speech combined with sign language, and speech combined with signing of the carrier phrase and fingerspelling of the CVC. Results indicated that vowels produced with accompanying sign language and fingerspelling were significantly longer in duration than those produced during speech alone. Further, it was found that in both the signed and fingerspelled conditions, as in speech alone, vowels followed by a voiced consonant were longer in duration than vowels followed by their voiceless cognate.
Durational rules from a speech data base
Authors: Carlson Roll , Granström Björn
Published: October 2005

Rules for segmental duration have been studied in the context of a speech data base that is under development in our department. The data base search procedures include the same kind of context sensitive rules that are used in our speech synthesis project [Carlson and Granström, Phonetica 43, 140–154 (1986)]. This affords the possibility of making a direct comparison to the data base durations when developing durational rules. Different kinds of speech material have been studied, including a novel and read sentences. Corresponding rules will be compared. Some different descriptive frameworks have been tried. A modified version of a rule structure suggested by Klatt has proven to be especially useful. [This work has been supported by grants from the Swedish National Board for Technical Development and the Swedish Telecom.]
Motor control mechanisms of stress production
Authors: Gracco Vincent L. , Haggard Patrick
Published: October 2005

For a variety of behaviors, emphasizing certain movements in a sequence can be used to establish perceptual saliency or vary communicative intent. The present investigation, part of a larger investigation of speech and nonspeech motor control mechanisms, was designed to evaluate modifications in movement sequences when subjects produced sentences under various emphatic stress conditions. Lip and jaw movements were compared using measures of displacement, velocity, duration, and relative timing of opening and closing. A secondary focus involved within-subjects comparison of the kinematic patterns of speech stress with those of stressed repetitive tapping. As in previous phrase-level speech investigations, local (stressed) and remote (nonstressed) timing effects were observed. In speech, all movements in the sequence were modified, not only the emphasized segment. The pattern of adjustments characterizing the local motor effects for speech was qualitatively similar to the motoric effects for stressed tapping. Emphasis of a particular component in a movement sequence may reflect a general motor strategy allowing flexibility while minimizing the number of basic motor processes. Specific kinematic adjustments will be discussed in relation to the underlying control mechanisms. [Work supported by NIH.]
Temporal compensation in interaccent intervals and polysyllabic words in spoken French
Authors: Fletcher Janet
Published: October 2005

“Syllable-timed” descriptions of French assume a monotonic increase in interaccent interval and polysyllabic word duration with increasing syllable count, unlike “stress-timed” languages. Two sets of French data consisting of six excerpts of spontaneous speech and a corpus of nonsense word data were analyzed to test these claims. Acoustic measurements of nonprepausal syllable and interaccent interval duration in the first corpus revealed that the latter was positively correlated with the number of syllables contained. There was evidence of negative acceleration of increasing unit length, an effect not reported previously. Temporal compression was most evident between monosyllabic and disyllabic units, radically reduced between disyllabic and trisyllabic units, and completely missing beyond three syllables. The second corpus revealed similar patterns of compression in tokens of one to three syllables in length. These results are not unlike those reported by Port (1981) for American English although the “absolute compression levels” were smaller in these French data. This relates to the vowel-quality preserving nature of French in unaccented contexts as opposed to an “underlying rhythmic tendency” to equalize syllable durations.
Prosodic components of speech in the expression of emotions
Authors: Kitahara Yoshinori , Tohkura Yoh'ichi
Published: October 2005

For the purpose of a natural and high-quality speech synthesis, the role of prosody in speech perception has been studied. Prosodic components, which contribute to the expression of emotions and their intensity, were clarified by analyzing emotional speech and by performing listening tests on synthetic speech. It has been confirmed that prosodic components, which are composed of pitch structure, temporal structure, and amplitude structure, contribute to the expression of emotions more than the spectral structure of speech. Listening test results also showed that the temporal structure was the most important for the expression of anger, while both amplitude structure and pitch structure were much more important for the intensity of anger. Pitch structure also played a significant role in the expression of joy and its intensity. These results suggest the possibility of converting a neutral utterance (i.e., one with no particular emotion) into utterances expressing various kinds of emotions. These results can also be applied to controlling the emotional characteristics of speech in synthesis by rule.
Nonlinear interaction of an acoustic wave and mean flow at a stagnation point (model verification)
Authors: Thompson Charles , Manley Martin
Published: October 2005

A model has been developed to describe the nonlinear interaction of an acoustic disturbance and the mean flow over a bluff body near the stagnation point. The model identifies the neutral stability condition and predicts the evolution in space and time of disturbances in unstable flow. The available experimental data regarding this interaction are extremely limited. Two sets of data that do shed light are those of Hassler (1971) and Colak-Antic (1971). These experiments concerned the effects of unsteady disturbances on a mean flow for a geometry similar to the model geometry. The flow visualizations and hot-wire anemometer measurements of these reports illustrate some of the complex phenomena involved in the interaction. Interaction model predictions will be compared with experimental results. [Work supported by Analog Devices Professorship.]
Nonlinear variation in waveform and attenuation of tone-burst sound waves with finite amplitude
Authors: Nakamura Akira
Published: October 2005

Propagation in a circular pipe of tone-burst waves with finite amplitude was simulated by a computer. The results are compared with some experimental results [Y. Watanabe and Y. Urabe, Proc. 11th ICA, Paris, Vol. 1, pp. 337–340 (1983)]. The attenuation is separated into two parts in the time profile of the tone-burst waveform for comparison. One is the attenuation of energy effectively corresponding to a period given by a summation of the head and tail half-periods in the time profile. The other is the attenuation per period of the sinusoidal part located between the head and tail parts. It is found that (1) the attenuations of the head plus tail are considerably smaller than the attenuation of the sinusoidal part, and agree with the theoretical values for N waves and also with the experimental results, and that (2) the attenuations of the sinusoidal part agree with the theoretical values for repeated sawtooth waves but does not agree with experimental values, because the envelope of the profile used in the experiments had been deformed into an irregularly shaped rectangle.
Acoustical considerations for two music instruction buildings
Authors: Richards Roy L.
Published: October 2005

The acoustical design features and performance data for music instruction and performance facilities at George Fox College in Newburg, Oregon (completed in 1982) and Whitman College in Walla Walla, Washington (completed in 1985) will be discussed. Since these facilities house high level activities that demand virtually no intrusion of sound from adjacent spaces, methods for achieving a high degree of sound isolation will be emphasized. At George Fox, the rehearsal rooms were located in a former gymnasium, thereby imposing design restrictions in addition to those dictated by a limited construction budget.
Sound reflections and their optical counterparts
Authors: Hook Julian L. , Gullerud Arne S. , Schomer Paul D. , Schousboe Ingvar
Published: October 2005

Light reflections can provide an easily understandable analogy to some acoustical features of architectural spaces. The interior surfaces of a 30-× 60-ft lecture/conference room were covered with reflective plastic. Reflections from various light sources were observed and photographed. Sound blasts were generated in the same room and the resulting reflections were recorded and analyzed. Results from the two experiments were compared in order to determine the nature and extent of the correspondence.
Optimizing home listening rooms
Authors: D'Antonio Peter
Published: October 2005

Various aspects of the listener, the loudspeaker, and the listening room will be discussed. The psychoacoustic mechanisms used by the auditory system are briefly reviewed to understand how the listening room can corrupt spatial and spectral textures. Experimental polar patterns, measured at the ear drum, for a human ear, a dynamic speaker, a dipole speaker, and an omnidirectional speaker, will be presented. TEF measurements will be used to demonstrate how the loudspeaker polar response dictates the type of acoustical treatment necessary. After a discussion of the principles behind the designs which comprise the RPG Home Concert Hall, a detailed outline of three listening room designs for dynamic speakers (Opus I), dipole speakers (Opus II), and spatially oriented or omnidirectional speakers (Opus III) will be presented. Experimental before and after TEF ETC measurements are presented and discussed.
The significance of background sound in acoustical privacy for multifamily dwellings
Authors: Foulkes Timothy J.
Published: October 2005

Background sound is generally recognized as an important consideration in achieving acoustical privacy for open plan as well as enclosed offices. Too often in the design of multifamily structures little systematic attention is given to the background sound levels that will actually exist in the completed dwelling spaces and therefore the ultimate acoustical privacy that will be experienced by the occupants. A number of recent case histories have been examined in terms of the sound isolation rating (NIC or STC) and background sound level (dBA) versus satisfaction. This effort suggests criteria in terms of both STC and background sound levels are necessary to adequately predict occupant satisfaction.
Scanning laser vibrometer system for structural intensity measurements
Authors: Stuart Alan D. , Pechersky Martin J. , Hayek Sahib I. , Suen B. C. T.
Published: October 2005

The steady-state real-time velocity response at successive locations on a beam are measured with a laser vibrometer and stored in a computer. The scanning system associated with the vibrometer consists of precision linear translation stages to control a lens/mirror combination. The laser beam is scanned along the length of the beam and the flexural vibration of a sinusoidally driven beam is measured at several locations. The amplitude and phase data are recorded at each location as well as a signal proportional to and in phase with the driving force. Knowing the distance between measurement locations, the recorded data are used to compute any of the following: spatial derivatives, transfer functions, and intensity.
Measurement of structural intensity in submerged plates and shells using nearfield acoustical holography
Authors: Williams Earl G. , Romano Anthony J.
Published: October 2005

Nearfield acoustical holography provides a complete mapping of the normal surface velocity distribution on the surface of a plate or cylindrical shell. For plates this measurement completely determines the full structural intensity (SI) in the plate and no assumptions need to be made about the wave field on the plate. In shells this normal velocity is not sufficient to determine the SI accurately (below the ring resonance) because of the coupling between in-plane velocity and out-of-plane velocity. Several techniques are presented to predict the in-plane velocities from a knowledge of the normal (radial) velocity taken from measured holographic data and the corresponding SI is calculated and compared. In addition, the instantaneous energy exchange between the shell and the nearfield in the fluid (the coupling between structural and acoustic intensity) is obtained from measured data and presented.
The use of optical techniques for monitoring fluid-structure interactions
Authors: Berthelot Yves H. , Lee Dowon , Jarzynski Jacek
Published: October 2005

The use of coherent light from laser sources has revolutionized the capabilities of measurement techniques in experimental fluid mechanics. In particular, laser Doppler velocimetry has become a standard tool for measuring nonintrusively the small-scale structure of turbulence in fluids. Similarly, laser vibrometers are becoming common instruments for detecting vibrations on solid surfaces. Interferometric measurements (homodyne or heterodyne) can provide very accurate surface vibration measurements, with resolution of a fraction of an Angstrom; subsequently, they are a powerful tool for monitoring fluid-structure interactions, especially for small scale phenomena. At larger scales, another powerful tool is the laser speckle and holographic interferometry which, when combined with optical Fourier transform techniques, can yield a direct visualization of wave propagation of the ω-k space (wave vector filtering). A recent effort has also been made to design a simple and rugged fiber optic laser probe that would be used to measure noninvasively the vector displacement of a vibrating structure. Such a probe allows the identification of both in-plane (short wavelength, acoustically inefficient) and out-of-plane (long wavelength, acoustically efficient) modes of vibration, and the conversion between these modes at discontinuities such as ribs on the surface. The relation between such vector measurements with acoustical holography and structural intensity will be discussed together with the use of scanning techniques. [Work supported by ONR.]
Simulation of array processing in three-dimensional noise fields: Suggested experiments
Authors: Perkins John S. , Pasewark Bruce H. , Kuperman W. A.
Published: October 2005

The growing capability to model three-dimensional noise fields in complex ocean environments taken together with concurrent recent developments in matched-field processing (MFP) suggests noise experiments that will shed light onto the physical processes generating and propagating the noise fields. These experiments should especially yield information concerning the noise field as it impacts on signal and/or array processing. Some of the expected (modeled) characteristics of low-frequency ambient noise in a deep ocean basin with realistic complexity and its subsequent impact on MFP are reviewed. For example, the effects on MFP of down-slope conversion from discrete sources (surface ships) and distributed sources (storms), and the effectiveness of various rejection techniques are demonstrated. These results suggest experiments to investigate the most important processes.
Update on an evolving model for predicting thermally induced noise from Arctic pack ice
Authors: Stein Peter J. , Lewis James K. , Denner Warren W.
Published: October 2005

Fracturing of Attic pack ice due to thermal stresses is known to be a source of higher frequency (> 300-Hz) Arctic ambient noise. Recently, Lewis and Denner [J. Acoust. Soc. Am. 84, 1444 (1988)] reported on a numerical model for predicting temperature profiles through the ice. They showed that ice temperatures, and thus the stresses that lead to fracturing, are a function of sensible heat flux, solar radiation, and long wave radiational heat flux. This implies a dependence on snow and cloud cover and explains some of the variations in higher frequency noise. Here an extension of the model to include estimation of stresses in the ice via a stress-strain rheology that includes creep is reported. These calculations can be used to predict failure of the ice at a given depth in the ice. The ice was found to fail not only near the surface, where the maximum temperature variations occur, but also deep within the ice. Acoustic data show that the radiation from the surface fracturing is stronger than the radiation from the deep fracturing. Variations in acoustic source strength for a crack in the ice as a function of depth within the ice may explain this feature. [Work supported by ONR.]
A switched-source model for simulating Arctic undersea noise
Authors: Nagle Samuel M.
Published: October 2005

A switched-source model is developed for simulating the impulsive character of Arctic undersea noise. The model is based on one proposed by S. V. Czarnecki [“Nearly optimal detection of signals in non-Gaussian noise,” Ph.D. thesis, Dept. of EECS, Princeton Univ. (October 1983)] where impulsive and normal background noise regions are treated as coming from two independent Gaussian sources with differing variance. P. K. Willet and J. B. Thomas [IEEE J. Ocean. Eng. OE-12, 29–37 (1987)] have suggested that the dual mode noise sequence can be treated as stationary and dependent if the state of the source selection switch is governed by a two-state Markov process. In this paper a statistical analysis is conducted on a 10-min time series of Fram 2 noise data in order to provide a complete stochastic description of real noise data within the framework of such a model. An earlier point process analysis is extended by examining the duration and amplitude of burst events. Results of the analysis are used to specify the dual source characteristics, and the terms of the transition matrix for the Markov process.