bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermoacoustics in irregular media.
Authors: Jensen Carl , Raspet Richard
Published: October 2013

One approach to acoustics in random porous media is to use fitting parameters to match theoretical models derived from exact parallel pore theory to measured values of the media’s acoustic properties such as the complex compressibility and complex density. [Roh et al. J. Acoust. Soc. Am., 121, 1413–1422 (2007)] extended these ideas to the more complicated thermoacoustic case of an applied temperature gradient by using empirical factors to reshape the known solution for thermoacoustics in a regular framework of rigid tubes to RVC and aluminum foam samples. The validity of this model has been investigated by directly simulating the sound propagation through several irregular, 3-D geometries using a thermal fluid solver. The acoustic and thermoacoustic simulation results for several geometries will be presented and compared to the theoretical results.
Miniature traveling wave thermoacoustic engine.
Authors: Rodriguez Ivan A. , Symko Orest G.
Published: October 2013

Five high frequency annular thermoacoustic traveling wave devices have been developed and characterized. A 1.27 cm bore diam 2 kHz engine was optimized, increasing its maximum acoustic output from 140 to 167 dB. A new 1.60 cm bore diam 2 kHz engine has been assembled with the expectation of even higher acoustical power output because power is proportional to cross-sectional area. In the 3 kHz regime, two geometries were investigated, an oval shape and more square version, which is easier to assemble. These devices were found to have comparable outputs suggesting that the square geometry is a viable alternative, and, thus, all additional devices were constructed this way. A 4 kHz engine was also studied. In order to measure the effects of the heat exchangers and regenerator assembly on the acoustic flow, a resonator tube was constructed. This tube was fitted with the device innards and driven by a speaker. An absorption coefficient of 0.4 was measured. This information along with the 916 T across the regenerator allows for an estimate of the limit on the acoustic gain of the system to be calculated. [Research supported by the U.S. Army Space and Missile Defense Command/U.S. Army Forces Strategic Command.]
Shampooing, skydiving, and the cochlear amplifier.
Authors: Shera Christopher A.
Published: October 2013

What is the evidence that the mammalian cochlea amplifies traveling waves? Although mechanical nonlinearity and physiological lability are both widely cited as such, neither constitutes evidence for actual power amplification. In fact, the only real evidence comes from cochlear modeling. In this presentation I describe two modeling strategies, “shampooing” and “skydiving;” discuss the relative strengths and weaknesses of the two approaches (more conventionally dubbed the forward and inverse method, respectively); and illustrate their application to cochlear mechanics. Skydiving with a parachute provides compelling evidence that the mammalian cochlea operates as a biological, hydromechanical analog of a laser amplifier. [Work supported by the NIH/NIDCD.]
Development of a revised loudness model.
Authors: Moore Brian C. J.
Published: October 2013

The loudness model developed in my laboratory was based on models developed by pioneers such as Fletcher and Zwicker. Their models involved calculation of an excitation pattern for the sound of interest, from the long-term average spectrum of the sound, transformation of the excitation pattern to a loudness pattern (specific loudness plotted as a function of frequency on a perceptually based frequency scale), and calculation of loudness from the area under the loudness pattern. The innovations used in the Cambridge model were: (1) Incorporation of a linear filter as a first stage, to account for the transmission of sound through the outer and middle ear; (2) Calculation of excitation patterns from extensive measurements of auditory filter shapes, using the notched-noise method; (3) Transformation of the frequency scale to the ERBN-number scale, which is similar conceptually to the Bark scale, but is different numerically, especially at low frequencies; (4) Transformation of excitation to specific loudness using a function such that loudness has a finite value at the absolute threshold, as opposed to zero loudness. More recently, the model has been modified to include the concept of binaural inhibition, to accommodate experimental evidence indicating that loudness does not simply sum across ears.
Binaural interaction modeling based on physiology.
Authors: Colburn H. Steven
Published: October 2013

Since psychophysical performance is based on information encoded by peripheral sensory receptors, this encoding and the resulting internal representation of sensory information impose limitations on psychophysical abilities. When enough knowledge and data are available to characterize the activity of the neurons carrying the relevant information, it is possible to derive implications for performance and constraints on mechanisms of performance. This approach has been applied for many years to multiple sensory modalities including vision and audition [e.g., Siebert, Kybernetik (1965)]. In this presentation, the impact of these ideas on understanding binaural processing will be discussed. As argued in many talks in this session, explicit models with the potential for quantitative predictions are an effective means to represent current understanding to explore hypotheses. [Work supported by NIDCD, grant No. DC-00100.]
Theories of hearing.
Authors: Viemeister Neal F.
Published: October 2013

One of the more compelling and important aspects of auditory science has been the ability to relate perception to physiology and physics. This challenging endeavor has attracted fine minds from various disciplines and has provided theoretical frameworks for rigorously studying and describing at various levels many basic aspects of hearing. An example is the application of “signal detection theory” and its collection of tools for empirical and theoretical investigation of certain aspects of audition. But what of the future? Do we have comparable tools to construct quantitative theories that enable prediction of complex aspects of audition? Do we need new tools? Definitive answers may or may not be provided during this session.
Relevance of psychoacoustical theory.
Authors: Hartmann William
Published: October 2013

Historically, the principles of psychoacoustics have been described in terms of mathematical theories. Are such mathematical theories now obsolete? Have they been replaced by computer algorithms? Do contemporary answers now come from simulations in computational toolboxes? The case for psychoacoustical theory can be made anew: Mathematical psychoacoustical theory has value because of the transparency of its assumptions and the universality of its language. It has an unparalleled ability to inspire extensions and revisions in order to evolve. It illuminates new conceptual directions through analogies with other sciences subserved by similar mathematical structures. Theory consolidates large amounts of otherwise unrelated data and serves as a guide to future experiments. Mathematical theory is the practical realization of images about the way the auditory world works, images that promote understanding because of their intuitive appeal. Theory is at its best when the ordinary operations of mathematics transform an initial model into logically inescapable new insights unlikely to have arisen by other avenues. [Work supported by the NIDCD, Grant DC-00181.]
Midfrequency acoustic radiation analysis.
Authors: O’Regan Stephen D.
Published: October 2013

Boundary, finite, and infinite element methods have proven useful for solving the 3-D acoustic wave equation at low frequencies. For high frequency, localized formulations such as plane-wave and ray-tracing methods have been applied successfully. These methods are impractical, inaccurate, or both for treating midfrequency problems. Low-frequency methods make very large demands on computer processing while high-frequency methods account only for local effects. Full-spectrum methods have been developed which apply interpolation between the low and high ends of the frequency range to estimate the response in the midfrequency. While these methods have provided some insight to trends as one moves toward the midfrequency range, it is not well established that they can reliably solve problems well away from their established limits. For surfaces with features having dimensions close to midfrequency wavelengths, the physics is distinct from those that govern low and high frequencies, and is not merely a linear combination of the two. This presentation reports on research to develop a midfrequency analysis tool that directly addresses the midfrequency physics. The author will identify the challenges in a physics-based method, discuss an approach to address them, and report on simulations exercising the approach.
The discontinuous enrichment method for multiscale and higher-frequency wave propagation problems.
Authors: Farhat Charbel , Tezaur Radek
Published: October 2013

Wave propagation problems pertain to many technologies including sonar, radar, geophysical exploration, medical imaging, nondestructive testing, and structural design. In the medium frequency regime, the analysis of these problems by the standard finite element method is either computationally unfeasible or simply unreliable, because of the well-known pollution effect. In practice, the higher-order (or p-type) finite element method alleviates this effect, but only to some extent. Alternative approximation methods based on plane waves have recently emerged to address this issue. The discontinuous enrichment method (DEM) is such an alternative. It distinguishes itself from similar approaches by its ability to evaluate the important system matrices analytically, thereby bypassing the typical accuracy and cost issues associated with high-order quadrature rules. DEM also provides a unique multiscale approach to computation by employing fine scales that contain solutions of the underlying homogeneous partial differential equation in a discontinuous framework. The theoretical and computational underpinnings of this method will be overviewed. Then, recent applications to underwater acoustic and elastoacoustic scattering as well as automotive structural vibrations in the midfrequency regime will be discussed. Accuracy of 1 to 2 orders of magnitude and/or solution time improvement over the higher-order Galerkin method will be demonstrated in three dimensions.
Recent innovations and current performance of conventional boundary element computations.
Authors: Fahnline John B.
Published: October 2013

As long as boundary element methods have existed, research has been ongoing to make the calculations faster and applicable for larger problems. The rapid rise in computing power, both in terms of processor speed and storage capacity, has increased the problem size that can be addressed and has led to many novel strategies for reducing the computational burden. For example, many of the matrices can be stored at coarse frequency spacing over the range of interest and interpolated at much finer resolution, reducing the computation times enormously. Other strategies for speeding the computations that will be discussed include condensed acoustic meshes, optimized math kernel libraries, and multipole expansions. Results will be presented to indicate typical computation times and problem size limitations.
Locating arbitrary noise sources in three-dimensional space in real time.
Authors: Zhu Na , Wu Sean
Published: October 2013

A portable, easy to use and effective device using four microphones only is developed for locating arbitrary noise sources in 3-D space in real time. The microphones can be placed anywhere in space so long as they are not on the same plane. This provides application flexibilities. Using cross-correlations, the differences in arrival times of these four microphone channels can be specified. This information together with a spherical spreading assumption of acoustic wave traveling in a free field enables one to determine the (x, y, z) coordinates of target sources. Error analyses are conducted and the impacts of signal noise ratios, microphone spacing, source distances, and frequencies on the accuracy of localization are examined. In particular, an empirical formulation for estimating the errors in locating a target source is developed. Using this empirical formulation, one can locate a target source for any given signal noise ratio, microphone spacing, source distance, and frequency range. Numerical simulations and experimental validations are conducted to check the effectiveness of this device to locate a variety of real world sounds, including truck pass-by noise, thundering, human voices, etc. Satisfactory results are obtained in most cases, even when the sources are behind the measurement microphones.
Low frequency radiation from a (compact) structure with and without sound holes.
Authors: Martini Kyle
Published: October 2013

At long wavelengths, a force driven, closed elastic structure radiates as a dipole. However, this may or may not be the case in the presence of a sound hole. Radiation remains dipole-like when the interior volume behaves as an acoustic fluid coupled to the structure. This is commonly referred to as the sound hole sum rule in musical acoustics [Weinreich (1985)]. However, should the interior acoustic volume be uncoupled, or simply ignored, the radiated field is dominated by a monopole contribution. For example, this may occur with mechanically isolated, piping systems exposed to the exterior medium. In this situation, the monopole or dipole nature of the radiation depends on the effective number of sound holes, for example, whether the driven system is well connected to the exterior along both the inlet and outlet. Finite element structural-acoustic models are developed and exercised to investigate these systems and issues. In addition, a substructuring technique is utilized to account for the potential influences of interior structural complexity.
The perception of word-final nasals in Southern Min and Mandarin Chinese.
Authors: Chen Ying , Guion Susan G.
Published: October 2013

There is a historical pattern of word-final nasal merger in Chinese languages. Some languages preserve the old Chinese final nasals /m, n, ŋ/, others preserve only /n, ŋ/, while others preserve only /ŋ/. The pattern of merger and loss, /m/ > /n/ > /ŋ/, may be due to a hierarchy of confusability among the nasals. Here, relative confusability of nasals was examined in identification tasks. Effects of vowel quality and lexical tone were also considered. First, perception of final nasals in the Quanzhou dialect of Southern Min, which preserves /m, n, ŋ/, found that /m/ was most often confused, while /n/ was least often confused. High vowel /i/ conditioned more mishearing than mid vowel /ə/ and low vowel /a/; low-level tone conditioned more mishearing than high-level, midlevel, midlow-rising and midhigh-falling tones. Second, perception of final nasals in Mandarin, which preserves /n, ŋ/, found that /n/ was more often confused than /ŋ/. High vowel /i/ again conditioned more mishearing than /ə/ and /a/; low-dipping tone conditioned more mishearing than high-level, midrising, and high-falling tones. The results do not strongly support the hierarchy of confusability among the nasals but suggest that high vowels and low tones condition more misidentifications.
Velarization of word-initial /l/ in African American English.
Authors: Van Hofwegen Janneke , Thomas Erik R.
Published: October 2013

Word-initial /l/ was examined in African American English in North Carolina, with comparisons with European American English, archival interviews with ex-slave African Americans and Spanish. The degree of velarization was measured using the F2-F1 difference in Bark. Interactions with formant values of the following vowel and the duration of /l/ were examined. Past research has produced conflicting results. First, initial /l/ in English is regarded as relatively unvelarized, but some research has found it to be velar. Second, there is disagreement about whether velar or nonvelar /l/ shows greater duration. Third, there has been controversy over whether velarization of /l/ is categorical or scalar. Results showed that English speakers exhibited significantly more velarization than Spanish speakers. Moreover, the degree of velarization increased across generations of African Americans. Less velarized /l/ proved to show greater duration than more velarized /l/. Velarization was quite scalar: there was no discernable division between more and less velarized tokens. /l/ tended to be more velar before a back vowel than before a front vowel, but this correlation showed no interaction with the observed generational and individual differences in velarization. [Work supported by NSF.]
Sound change and perceptual weight of acoustic correlates to Korean stops.
Authors: Kang Kyoung-Ho , Guion Susan
Published: October 2013

The Korean stop system is experiencing a sound change. Younger Korean speakers born in the 1970s or after produce aspirated and lenis stops differently from older speakers. Results from clear speech production experiments revealed differences in clear speech enhancement patterns. Older speakers enhanced voice onset time (VOT) difference, whereas younger speakers primarily enhanced F0 difference [K.-H. Kang and S. G. Guion, J. Acoust. Soc. Am. 124, 3909–3917 (2008)]. These results indicate that older and younger speakers have different phonetic targets for the production of stops. The primary goal of the current study was to examine any perceptual differences related to the production differences. In order to assess the extent to which acoustic correlates to the stops contribute to the identification of the Korean stops, a perception experiment using resynthesized stimuli was conducted. Younger (n= 10, mean of 20.2 years old) and older listeners (n= 10, mean of 48.5 years old) participated in a stop identification task. The results suggested that F0 is a more weighted correlate than VOT for younger listeners for the distinction of the aspirated and lenis stops.
Phonation categories in Cajonos Zapotec.
Authors: Tejada Laura
Published: October 2013

Phonation categories such as breathy, modal, and creaky have been described using the acoustic measurements (H1–H2) and (H1–A1). The measure (H1–H2) is the difference in dB between the first and second harmonics and is used to approximate the proportion of a glottal cycle in which the glottis is open (the open quotient). (H1–A1) is the difference in dB between the first harmonic and the most prominent harmonic in the F1 region. (H1–A1) is used as a measure of F1 bandwidth that is related to degree of glottal opening. These measures were applied to an undocumented variety of Villa Alta Zapotec spoken in San Miguel Cajonos. Acoustic data from four speakers were analyzed. Measures were taken at four evenly spaced points in time for /i/, /e/, /a/, and /o/. Results show that (H1–H2) and (H1–A1) discriminated correctly between the categories breathy, modal, and creaky with varying percentages of accuracy at different time points. (H1–H2) had a (58%) accuracy rate at time point three, compared with (63%) for (H1–A1). Combining the two measures showed that the accuracy rates rose from point one (50%) through points two (61%) and three (65%), and fell slightly at point four (58%).
The phonetics of contrastive phonation in Gujarati.
Authors: Khan Sameer ud Dowla , Thatte Victoria
Published: October 2013

Gujarati is known for distinguishing breathy and modal phonation in both consonants and vowels [(Cardona and Suthar, 2003)], e.g., /ba:r/ “twelve” versus /Ba:r/ “burden” versus /bA:r/ “outside,” where uppercase represents breathiness. The current study investigates acoustic and glottographic properties of this three-way contrast. [Fischer-Jo/rgensen (1967)] and [Bickley (1982)] showed that the H1-H2 measure can reliably distinguish breathy and modal vowels, and [Esposito (2006)] further found that Gujarati listeners exclusively attend to H1-H2 to categorize audio samples from other languages, even when H1-H2 did not reliably distinguish contrastive voice quality in those languages. However, do other acoustic properties also distinguish breathiness in Gujarati? In addition what physiological differences underlie the acoustic differences? The current study tests the reliability of several phonetic measures (e.g., H1-H2, H1-A1, CPP, CQ, etc.) to distinguish 33 (near-) minimal sets contrasting breathy and modal segments in audio and electroglottographic data produced by both male and female Gujarati speakers. [Work supported by NSF].
A study of articulatory kinematics of American English diphthongs.
Authors: Lee Sungbok , Byrd Dani
Published: October 2013

Diphthongs are acoustically characterized by formant movements between initial and final vocalic segments [cf, Holbook and Fairbanks, J. Speech Hear. Res., (1962); Thomas Gay, J. Acoust. Soc. Am., (1968)]. It has been observed that the initial (onset) and final (offset) portions may not correspond to typical monophthongal vowels and that there exists more acoustic variability in the offset portions than in the onset portions. Spectral transition rates have been found to be different from diphthong to diphthong. In the current study, the articulatory properties of American English diphthongs are investigated in tandem with their acoustic properties. We collected both acoustic and articulatory data of five diphthongs and seven monophthongs in [b-t] context embedded in a carrier sentence using electromagnetic articulography. The data were recorded from two male and one female subjects, and each diphthong was repeated five times. The main analysis focus is on the kinematic characteristics of the three different tongue sensors (tongue tip, tongue dorsum, and tongue rear) in each diphthong production and the comparisons to monophthongs that are close to either the onset portion or the offset portion of the given diphthong. [Work supported by NIH.]
An articulatory study of lexicalized and epenthetic schwa using real time magnetic resonance imaging.
Authors: Lammert Adam , Bresch Erik , Byrd Dani , Goldstein Louis , Narayanan Shrikanth
Published: October 2013

Debate exists about the nature of schwa in terms of articulatory planning and execution. It is commonly believed that schwa lacks a specific constriction target. Another view is that the constriction target for schwa is the mean of the language’s targeted vowels. Some have argued that both lines of thinking are correct [I. Smorodinsky, J. Acoust. Soc. Am. 109, 2446 (2001)]. Specifically, epenthetic schwas (e.g., needed) may indeed be targetless, while lexical schwas (e.g., panda) have a target. To investigate this, we collected midsagittal realtime l MR images [S. Narayanan et al., J. Acoust. Soc. Am. 115, 1771 (2004)] from two native English speakers. The speakers read sentences aloud which contained, variously, lexical or epenthetic schwas in multiple contexts. Images of the various schwas were extracted from the MR data and a profile of the vocal tract was fit to the image. If both targeted and targetless schwas exist, then they should be evident by examining the vocal tract shape in these images. Lexical schwas, if they are targeted, should have relatively low variability as compared to epenthetic schwas. Conversely, the vocal tract shape during epenthetic schwas should be highly correlated with the surrounding vowel context. [Work supported by NIH.]
Evidence of an articulatory saturation effect in the production of /s/ in American English.
Authors: Perkell Joseph S. , Matthies Melanie L. , Tiede Mark
Published: October 2013

Previous work [JSLHR, 47, 1259–1269 (2004)] demonstrated that speakers of American English who consistently activated a contact sensor on the lower alveolar ridge with the tongue tip during /s/ but not /sh/ tended to produce greater sibilant contrast than speakers who did not consistently show this contact difference. This result is compatible with the existence of a sublingual cavity during /sh/ that is eliminated by the tongue-ridge contact for /s/, which creates an abrupt decrease in volume and resulting rapid increase in resonant frequency of the cavity anterior to the sibilant constriction. This study uses data from articulatory movements (EMMA), contact of the tongue tip with the alveolar ridge, and analysis of the acoustic signal to investigate a hypothesized articulatory saturation effect: abrupt articulatory and acoustic changes result from continuous forward movement of the tongue, which does not have to be controlled precisely in stopping at /s/ onset. In tentative support of this hypothesis, preliminary observations from productions of continuous /sh/-to-/s/ transitions show movements of tongue-blade points, which slow but do not stop immediately following articulatory contact and/or a rapid rise in sibilant spectral mean. Additional tests of the hypothesis and corresponding results will be reported. [Work supported by NIDCD.]
Relation of vocal tract constriction location to identification of voiced stop consonants.
Authors: Story Brad H. , Bunton Kate
Published: October 2013

Consonant identification experiments are typically based on stimuli produced with a formant synthesizer where a particular acoustic characteristic is varied along some continuum of values (e.g., onset frequency of F2). In this experiment, however, vowel-consonant-vowel (VCV) stimuli were generated with a synthesizer based on a kinematic model of the vocal tract shape [B. H. Story, JASA, 117(5), 3231–3254 (2005)] where the acoustic characteristics result from the time-varying tract configuration. Each VCV was produced by superimposing a constriction at a particular location within the vocal tract on an underlying vowel-vowel sequence. Five different vowel-vowel sequences were produced, and for each, a constriction was imposed at 20 consecutive locations extending from the lips to approximately the velum. VCVs were presented in random order, ten times each, to ten listeners, using a forced choice paradigm where only the voiced English consonants /b, d, g/ were available. Listener responses indicated that the relation of formant frequencies near the consonant, to those of the preceding or succeeding vowel can provide reasonably accurate predictions of regions within the vocal tract that correspond to specific consonants. It was also revealed that the location and length of each region is dependent on the vowel. [Research supported by NIH R01-DC04789.]
Phonetic properties of syllabic consonants in Slovak.
Authors: Pouplier Marianne , Beňuš Štefan
Published: October 2013

Studies on the articulatory correlates of syllable structure have shown that onset and coda consonants differ systematically in the timing and amplitude of their movements, and their temporal coordination with the vocalic syllable nucleus. Little is known, however, about consonants functioning as syllable nuclei. We present EMA data on Slovak, a language that allows the liquids /l/ and /r/ to be syllabic nuclei of CCC syllables. Phonologically, syllabic consonants behave like vocalic nuclei. We investigate the kinematic properties of syllabic consonants, and potential differences between vocalic and consonantal nuclei in their patterns of coordination with onsets and codas. Our data indicate that liquids in onset clusters are shorter than singletons (e.g., /r/ in “mrak” < “rak”), yet syllabic consonants (/r/ in “mrk”) pattern durationally with singletons. Generally, Slovak onset clusters show little or no overlap, which may result in an open transition schwa. For C1C2C3 syllables, C1-C2 show more overlap compared to an onset cluster, yet open transition schwas can still be observed (“m̂rk”). C2-C3 overlap less than C1-C2 in terms of movement onset, yet C1-C2 show a bigger plateau lag. These data contribute to our knowledge about the phonetic nature of syllabic consonants and articulatory correlates of syllable structure.
Rate conditioned variability in Western Andalusian Spanish aspiration.
Authors: Parrell Benjamin
Published: October 2013

Western Andalusian Spanish normally shows aspiration of /s/ in coda position, but post-, rather than pre-, closure aspiration in /s/ + /p,t,k/ sequences. This has been hypothesized to be the result of gestural reorganization, with pre-closure aspiration the result of anti-phase coordination and post-closure the result of in-phase [Torreira, 9th HLS, 2007]. This experiment explores this hypothesis by leveraging the fact that fast speech can lead to instability in gestural organization and even a spontaneous switch from anti- to in-phase coordination [Turvey, Am. Psych., 1990]. Subjects produced words with the target /s/+/p,t,k/ sequences in time with an acoustic metronome that steadily increased in rate. Results show three patterns of production: consistent preaspiration, consistent postaspiration, and a transition from pre- to post-aspiration as rate increased, corresponding to anti-phase, in-phase, and an anti- to in-phase transition, respectively. Excluding the trials with consistent postaspiration, which would not be expected to transition given their stable in-phase coordination, postaspiration increases as rate increases. If there were no change in gestural coupling, we would expect the opposite pattern: as rate increases, VOT should decrease. The result thus supports the original hypothesis that postaspiration in these sequences is the result of gestural re-phasing.
A production study on phonologization of /u/-fronting in alveolar context.
Authors: Kataoka Reiko
Published: October 2013

Recently many researchers modeled sound change as the result of phonologization [Hyman (1976)], a process whereby coarticulatory perturbation of a speech sound becomes intended properties of the sound. Although phonologization is a useful concept, diagnostic criteria have yet to be proposed. By using /u/-fronting in alveolar context in American English as a case study, this paper demonstrates how production data of various speech rates may be used to differentiate phonologized speech variations from mechanically caused variations. English speakers produced /CuC/ forms where the place of both Cs was either alveolar (text context) or other (control context), in fast, medium, and slow speech rates. [Lindblom (1963)] demonstrated that the magnitude of coarticulatory influence on the vowel reduces as the vowel’s duration increases. Thus, if the fronting of the vowel in alveolar context persists regardless of its duration, then this would constitute as evidence for phonologization. The results from a study with 30 speakers show that the vowels had significantly higher mean F2 values in alveolar contexts than in bilabial or zero contexts even in slow speech rate, suggesting that speakers have distinct production goals for /u/s in different contexts, or /u/-fronting has been phonologized.
Acoustic analysis of the tones and tone sandhi in Hakka Chinese.
Authors: Zee Eric , Lee Wai-Sum
Published: October 2013

This paper analyzes F0 contours of (i) the six citations tones of Hakka Chinese which consist of four long tones that occur on open syllables and closed syllables with a nasal and two short tones on checked syllables and (ii) tone contours on 36 bisyllabic compounds, representing possible permutations of the six citation tones, and 120 commonly used trisyllabic compounds. Based on the F0 data, (i) tone values are assigned to the citation tones and (ii) tone patterns on the bisyllabic and trisyllabic compounds are defined. Tone sandhi rules are formulated, summing up the phonological changes in the citation tones when juxtaposed. Phonetic tonal co-articulations are also examined. The F0 data show that the citation tones may be represented in terms of tone letter as [53 31 33 11] (long) and [5 32] (short). Major tone sandhis include [33] becoming [35] and [53] becoming [55] before [11], [31], or [53]; and before another [31], [31] becomes [33]. Process such as [53 53 53 53] becoming [5 5 5 53] illustrates simultaneous application of tone sandhi to only tones on the non-compound-final syllables, and [5 33 11 53 31] do not undergo tone sandhi before [5] or [33].
Contextual tonal variation in level tone languages.
Authors: Yu Kristine M.
Published: October 2013

While contextual tonal variation in languages with contour tones has been well studied [Han and Kim (1974); Gandour (1992); Xu (1994)], contextual tonal variation has been less well-studied in level tone languages [Meyers (1976)]. The acoustic variation of tones due to different tonal contexts in Hausa, Bole (with two tones H and L) and Yoruba (with three tones H, M, and L) will be investigated. The description of cross-linguistic contextual tonal variation is essential for understanding the task that infants are undertaking in acquiring tonal categories in the face of variance in tonal realization. The focus of the investigation will be how the acoustic variation compares to that in languages with contour tones and if there are general patterns across languages or language-specific differences in variation.
Perceptional experiment on Mandarin tones by Mandarin, Spanish, and Cantonese speakers.
Authors: Ke Yi-Chu , Teng Mu-Ling , Chen Chu-ting , Ip Lai-Iok , Lu Bo-hong , Chen Shih-wen , Yu Hsiu-Min , Pan Ho-hsien
Published: October 2013

This paper discussed perception of three contrastive Mandarin tones: high tone (Tone1), rising tone (Tone2), and falling tone (Tone4). Based on the previous study by Hallé (2004), in which tone (Mandarin) and non-tone (French) speakers joined, our perceptional experiment employed both identification and discrimination paradigm, and categorical result of tones was expected. We recorded two Mandarin words “tu” and “wa” in those three contrastive tones, and these six words were manipulated into same duration. We then synthesized the F0 of Tone1 to Tone2, Tone1 to Tone4, and Tone2 to Tone4 in seven steps. Subjects were separated in accordance to their mother tongues, namely Mandarin, Spanish, and Cantonese. Categorical perception is obvious in Mandarin group. Cantonese speakers revealed a similar categorical pattern to Mandarin speakers, while Spanish speakers showed no categorical pattern. On the whole, Mandarin speakers had an earlier dropdown on second or third step over each pair of tone stimuli.
Breathing behavior in relation to prosody and linguistic structure in spontaneous speech.
Authors: Watson Peter J.
Published: October 2013

Hird and Kirsner [K. Hird and K. Kirsner, Brain Lang., 80, 536–555 (2002)] reported that F0 is reset at higher values at the beginning of grammatically complete sentences during spontaneous speech. Hird and Kirsner reported that inspirations taken at the beginning of complete sentences “appeared” to be deep, but they did not make physiological measures of breathing behavior. [Watson, et al. J. Acoust. Soc. Am., 113, 2812–2819 (2003)] found that when sentences were read aloud at higher values within the vital capacity they were initiated at higher F0s; however, these measures were not made during spontaneous speech and grammatical structure was not varied. For this study, we measured breathing behavior using Respitrace while three women and one man were interviewed. Posthoc, breath groups were grammatically organized according to the method used by Hird and Kirsner. On average, breath groups that comprised complete sentences were initiated from higher lung volumes and F0 was reset at higher levels at the beginning of these breath groups. Results will be discussed in relation to the interaction of linguistic structure and breathing behavior.
How do ordinary listeners perceive prosodic prominence? Syntagmatic versus paradigmatic comparison.
Authors: Mo Yoonsook , Cole Jennifer , Hasegawa-Johnson Mark
Published: October 2013

In comprehending speech, listeners are sensitive to the acoustic variation encoding the prosodic structures that mark phrasing and prominence. The present study, based on prosody transcriptions of untrained listeners (74 monolingual American English speakers), tests which acoustic feature or feature combinations cue prosodic prominence, and specifically, whether ordinary listeners perceive prosodic prominence based on changes in acoustic measures in the local context (syntagmatic comparison) or based on the value of an acoustic measure relative to the distribution of that measure across all instances of the specific phoneme in the listener’s experience (paradigmatic comparison). Subjects listened to 36 short excerpts (11–25 s) of spontaneous speech from the Buckeye Corpus, and marked prominent words on a transcript. After evaluating intertranscriber agreement rates, acoustic measures (duration, intensity, subband intensities, F0 max, and formants) were extracted from stressed vowels and normalized within two domains (syntagmatic/paradigmatic). The results show that all the acoustic measures are correlated with perceived prominence and combinations of the acoustic measures account for the variability in listeners’ perception of prominence. Moreover, syntagmatically normalized acoustic measures explain more of the variability, indicating that ordinary listeners perceive prosodic prominence based on local changes in acoustic measures and especially in changes in overall intensity.
Computational modeling of juncture strength using articulatory synthesis of prosodic gestures.
Authors: Lee Sungbok , Parrell Benjamin , Byrd Dani
Published: October 2013

Prosodic boundary gestures or “pi-gestures” (Byrd and Saltzman, J. Phonetics, 2003) have been introduced to model the local slowing or lengthening of articulatory gestures in the vicinity of phrase boundaries. Computational modeling of articulatory dynamics is an important tool in assessing the predicted effects of pi-gestures of varying boundary strength on constriction gestures in varying contexts. We simulate pi-gestures within the TaDA task dynamics computational model [Nam and Kim, JASA, 116, 172–185 (2004)] and examine how functional data analysis can provide a tool for connecting articulatory lengthening with underlying pi-gesture activation strength. Specifically, the model is applied to the articulatory synthesis of two sequences: [CV#CV] and [CVC#CV], where C is bilabial or alveolar. The pi-gesture’s midpoint is coordinated synchronously with the midpoint of following consonant’s constriction gesture, and pi-gesture activation strength and duration are manipulated. Results indicate that pi-gesture activation strength has a much stronger effect on slowing than its duration. The slowing effect is asymmetrical, skewed earlier than the midpoint in the pi-gesture interval. After removing linear-time slowing effect (i.e., after length normalization), the slowing effect is slightly stronger in [CV#CV] than in [CVC#CV]. The strength of pi-gesture also affects spatial articulatory characteristics depending on constriction location and sequential context. [Work supported by NIH.]
Boundary- and prominence-related lengthening and their interaction.
Authors: Katsika Argyro
Published: October 2013

The durational effects of prosodic boundaries and prosodic prominence are well known, but their interaction is less well-understood. Recent studies in English [Turk and Shattuck-Hufnagel (2007); Byrd and Riggs (2008)] indicate that the two effects might be interdependent. Two acoustic experiments are presented, examining the role of boundary- and prominence-related lengthening and their interaction in Greek. The first experiment explores the effects of boundary-adjacent lengthening (conditions: no boundary, intermediate phrase, intonational phrase) and prominence (on the first, second, and third syllable away from the boundary). The second experiment examines these same effects, but post-boundary. Data from eight speakers were collected. The results from five speakers are presented. Results show that pre-boundary, both prominence and boundary have an effect on segment duration. Two prosodic levels (the level of word and one higher level) are distinguished. Furthermore, for two speakers, there is an interaction effect, such that three prosodic levels are distinguished when the prominent syllable is boundary-adjacent. The post-boundary condition shows less systematic results, with different speakers exhibiting different patterns. These results suggest that prosodic effects are speaker dependent, more stable pre-boundary, and that prominence and boundaries interact, increasing prosodic boundary marking. Implications for models of prosodic structure are discussed.
Rhythmic structures in content word untterances.
Authors: Lee Joo-Kyeong , Kang Sunmi
Published: October 2013

This study investigates rhythmic structures in the utterances composed of only content words. Content words are potentially accentable in utterance, and English necessitates a rhythmic alternation between strong and weak beats. What will happen if only content words are sequenced and they are all one-syllable words? A phonetic experiment was conducted to see if a rhythmic pattern is still produced in content word utterances and how it is manifested along the intonational contours. Results showed that merely 7% of the utterances were produced with every content word accented. Most utterances were rhythmically produced with every two (38%) or three (26%) words accented, and the other patterns such as a H* and L* alternation, two H*’s intervened with L-, and consecutive downstepped H*’s were interpreted as conforming the tonal rhythm [J.-K. Lee and S. Kang, Korean J. Speech Sci., 10(2), 303–317 (2003)]. In two-syllable content word utterances, the patterns where two words were unaccented suggest that strong and weak rhythmic beats should be counted with the number of words rather than syllables at the level of utterance. It is proposed that it is an accentual foot as opposed to a lexical foot at the level of lexical word.
Perception of intonation as a function of sex.
Authors: Chen Yu-Wen , Watson Peter J.
Published: October 2013

Fitzsimons et al. [M. Fitzsimons, N. Sheahan, and H. Staunton, Brain Lang. 78, 94–108 (2001)] reported differences in the production of intonation between men and women during speech production. A relationship between the production and perception of segmental variables has been recognized [J. Perkell et al., Speech Commun. 22, 227–250 (1997)]; however, little information is available about the relationship of prosodic perception and production. Five men and five women listened to sentences produced by one man and one woman. The fundamental frequency (F0) of each sentence was resynthesized with 22 levels of F0 variation ranging from no variation to F0 variation that was 3.5 times greater than the typical variation of a sentence. For each sentence, a listener was randomly presented one of the levels of F0 variation and asked to adjust variation up and down until they were satisfied that the variation of that sentence sounded the most “natural.” Additionally, each subject read a set of sentences aloud, and the F0 variation of these productions was analyzed. Results will be discussed in relation to the production and perception of intonation within and between the men’s and women’s groups.
Perceived sexual orientation and speech style: A perceptual and acoustic analysis of intentionally clear and conversational speech.
Authors: Munson Benjamin , Ferguson Sarah Hargus , Connealy Catherine L.
Published: October 2013

Munson et al. [Journal of Phonetics (2006)], found a correlation between perceived speech clarity and perceived sexual orientation (PSO) of male talkers: those who had been rated to sound gay were rated by an independent group to produce speech clearly. A smaller, opposite influence was found for women talkers. Munson et al. hypothesized that gay male speech styles might be based, in part, on clear speech styles. One weakness of Munson et al.’s study was that none of the speech examined was intentionally clear. This study follows up on this finding. A new group of 29 listeners rated the PSO of four men and four women producing conversational and intentionally clear speech, recorded as part of a larger study on interspeaker differences in talker intelligibility. PSO was rated using a five-point scale. Speech style had a moderate, statistically significant influence on PSO. In contrast with previous research, both men and women were rated as gayer-sounding when producing clear styles than when producing conversational ones. The differences in mean ratings were small. This investigation, thus, partly supports Munson et al.’s findings. The relatively small influence of speech style on PSO likely reflects the complex, content-dependent nature of gay speech styles and PSO.
Enhancing passive automation performance using an acoustic propagation simulation.
Authors: Llorens Ashley J. , Philip Trudy L. , Schurman Iman W. , Lorenz Cory R.
Published: October 2013

During an at-sea encounter, signatures of interest can exhibit characteristics that differ from those observed in previously recorded data. These differences can occur due to variations in a number of factors including encounter geometry, propagation channel, and receiving sensor configuration. This paper presents a simulation technique that imposes low-frequency propagation effects on a time-domain signal using a normal mode method. High-quality, time-varying recorded signatures are used as inputs into the algorithm, which outputs band-limited time-series data for a selected geometry and environment. The output time-series are phased to simulate the time-varying pressure amplitudes that would be received by a towed array or any multielement passive sensor configuration operating in a realistic multipath environment. These capabilities enable the simulation of signatures of interest as captured under a broad range of littoral conditions by various passive sensors. These simulated data are used to augment scarce signature collections for training and assessing the performance of passive sonar automation.
Pulse propagation and classification in time/frequency and position/wave number phase space.
Authors: Loughlin Patrick
Published: October 2013

In dispersive pulse propagation, different frequencies travel at different velocities, and, hence, the pulse is nonstationary in that it changes over time and distance. Joint phase space representations, such as the Wigner distribution and the spectrogram, are often employed to study nonstationary signals, and, hence, it is natural to consider their application to dispersive propagation. We consider position/wave number and time/frequency representations of a pulse propagating with dispersion and damping. We give the Wigner distribution of the pulse at a particular time/position in terms of the Wigner distribution of the initial pulse. Approximations of this result are derived, which are accurate and remarkably simple to apply, as compared to the stationary phase approximation. The approximations provide insights as well, in that they show how each point in phase space propagates at the group velocity, and lead to new features for classification, based on local phase space moments, that are invariant to the propagation effects of dispersion and damping. Examples relevant to sound propagation and classification in shallow water are presented. [Work supported by ONR Grant No. N00014-06-1-0009.]