bluuebunny/crossref_metadata_2025 huggingface dataset:
Near-field correlation and coherence of military jet noise
Authors: Harker Blaine M. , Gee Kent L. , Neilsen Tracianne B. , Wall Alan T. , James Michael M. , McInerny Sally A.
Published: September 2012

Correlation and coherence analyses in the near field of military jet noise provide insight into source and radiation characteristics. Data were measured parallel to the exhaust centerline of an F-22A Raptor and spatial correlation and coherence values were calculated. Low spatial correlation at the sideline indicates radiation dominated by multiple incoherent sources. In contrast, the downstream region is characterized by high spatial correlation, suggesting radiation primarily from large-scale turbulent structures. Variations in spatial correlation in the axial direction can be related to the spectral dependence on measurement location, which supports the idea of a two-source jet-noise model. Coherence calculations, which decompose the correlation information into narrow frequency bands, further support this idea. [Work supported by the Office of Naval Research.]
Nusselt numbers of laminar, oscillating flows in stacks and regenerators with pores of arbitrary cross-sectional geometry
Authors: Brady John
Published: September 2012

General expressions for the Nusselt numbers of laminar oscillating flows within the pores of stacks and regenerators are derived from thermoacoustic theory developed by Rott and Swift. These expressions are based on bulk (velocity-weighted, cross-sectionally averaged) temperature, rather than the cross-sectionally averaged temperature. Two cases are considered: flow with oscillating pressure and no external temperature gradient, and oscillating velocity within an external temperature gradient and negligible pressure oscillations. These expressions are then applied to parallel plates, circular pores, rectangular pores, and within the boundary layer limit. Steady-flow Nusselt numbers are recovered when the thermal penetration depth is at least as great as the hydraulic radius of the pore. In addition, temperature and flow profiles within this regime are like those of steady flows.
Acoustic radiation force and radiation torque on Rayleigh particles
Authors: Lobo Tiago P. , Silva Glauber T.
Published: September 2012

In this work, the acoustic radiation force and radiation torque exerted by an arbitrary shaped wave on a spherical particle in the Rayleigh approximation (i.e. the incident wavelength is much smaller than the particle dimensions) are discussed. The host fluid in which the particle is suspended is assumed to be inviscid. Expressions for the force and the torque are obtained in terms of the incident acoustic fields, namely pressure and particle velocity. As it turns out, the obtained radiation force expression represents a generalization of Gor'kov's formula [Sov. Phys. Dokl. 6, 773-775 (1962)]. Moreover, the radiation torque can be expressed in terms of the incident Reynolds' stress tensor. The method is applied to calculate both radiation force and radiation torque produced by Bessel beams. It is demonstrated that only the first-order Bessel vortex beam generates radiation torque on a particle placed in the beam's axis. In addition, results involving off-axial particles and Bessel beams of different order are illustrated.
Impact of rigid sphere scattering on measurement of acoustic shocks
Authors: Muhlestein Michael B. , Thomas Derek C. , Gee Kent L.
Published: September 2012

Multi-microphone arrays embedded in a rigid spherical housing have been used to estimate field quantities such as vector intensity. However, the measured pressure waveforms are modified by the scattering of the incident pressure wave on the sphere. The frequency response function and the corresponding impulse response function for microphones in a sphere can be created using Mie scattering theory. This permits analysis of the scattering effect on pressure measurements for shock-containing broadband waveforms, such as those produced by solid rocket motors. The abrupt pressure rises associated with shocks are seen to be either overestimated or underestimated depending on the angle of the measuring microphone. These shocks are the most affected portion of the waveform due to their high frequency content. In addition, deconvolution of measured rocket signals using the predicted impulse responses of the microphones in the array provides an apparently consistent estimate of the free-field signal at the probe center.
The nonlinearity parameter, B/A, in FC-43 Fluorinert up to 373 K and 13.8 MPa
Authors: Sturtevant Blake T. , Pantea Cristian , Sinha Dipen N.
Published: September 2012

Acoustic imaging systems based on the parametric array concept utilize a nonlinear medium for mixing high frequency sound into a beam of low frequency collimated sound. Fluorocarbon fluids are very appealing as nonlinear mixing media with values of the nonlinearity parameter, B/A, typically greater than 10 at ambient temperature and pressure. To design acoustic imaging systems for high temperature and high pressure environments, such as found in geothermal and petroleum wells, it is important to know how B/A varies with temperature and pressure. This work reports the determination of B/A in FC-43 at temperatures up to 373 K and pressures up to 13.8 MPa using the thermodynamic method. Sound velocities were measured using Swept Frequency Acoustic Interferometry at 11 pressures between ambient and 13.8 MPa along 6 isotherms between ambient and 373 K. A 3rd order least-squares fit of measured sound speeds was used to determine temperature and pressure dependence. The B/A of FC-43 was found to increase with both temperature and pressure near ambient conditions and to go through a maximum around 340 K and 6 MPa.
Temporal weighting of interaural time and level differences carried by broadband noises
Authors: Stecker G. C.
Published: September 2012

Localization of real sounds involves integrating acoustic spatial cues as they evolve over time. This study measured binaural sensitivity over time, in the form of temporal weighting functions (TWFs) for trains of of noise bursts. Each stimulus comprised sixteen 1-ms bursts of white noise, presented at an interval (ICI) of 2 or 5 ms. In separate conditions, noise samples were either repeated (“frozen”) or newly generated (“fresh”) across bursts. On each of many trials, listeners indicated the apparent lateral position of a stimulus along a horizontal scale displayed on a touch-sensitive device. Lateral positions varied across trials as interaural time (ITD) and level (ILD) differences ranged +/-500 µs ITD or +/-5 dB ILD. Interaural differences of individual bursts in each train received additional random variation (ranging +/-100 µs and +/-2 dB) to allow calculation of TWFs by multiple linear regression of normalized responses onto per-burst ITD and ILD values. Consistent with past studies, TWFs for “frozen” noise-burst trains demonstrated large ICI-dependent weights on the initial burst (“onset dominance”), elevated weights near offset, and lower weights for interior bursts. Flatter TWFs, smaller onset/offset weights, and greater interior weights were measured for “fresh” vs “frozen” noise burst trains. [Supported by R01 DC011548.]
Response to a pure tone in a nonlinear frequency-domain model of the cochlea
Authors: Meaud Julien , Grosh Karl
Published: September 2012

The nonlinear response of the cochlea to a pure tone is simulated using a novel computational model. In this physiologically-based finite element model, the three-dimensional intracochlear fluid dynamics are coupled to a micromechanical model of the organ of Corti and to electrical potentials in the cochlear ducts and outer hair cells (OHC). Active feedback due to OHC somatic electromotility is represented by linearized piezoelectric relations and is coupled to the nonlinear hair-bundle mechanoelectrical transduction current. Using an alternating frequency/time method and a single set of parameters, we simulate the compressive nonlinearity, harmonic distortion and DC shifts in the response of the cochlea to a single tone. Model predictions agree well with available experimental data.
Pole-zero characterization of middle ear acoustic reflectance data
Authors: Robinson Sarah , Nguyen Cac , Allen Jont
Published: September 2012

Middle ear acoustic reflectance (AR) measurements have valuable clinical applications. AR is measured using a foam-tipped probe sealed in the ear canal, containing a microphone and receiver (i.e. MEPA3 system, Mimosa Acoustics). From the complex pressure response to a broadband stimulus, the acoustic impedance and reflectance of the middle ear can be calculated as functions of frequency. A sizeable pool of normal and pathological AR data, collected by various researchers, indicates that many pathological ears have an AR that systematically differs from normative data. Assessment of such data typically relies on consideration of the magnitude AR, or separate consideration of AR magnitude and phase. By fitting poles and zeros to AR data, we have achieved a compact and accurate representation of the complex data (<5% RMS relative error). It was found that removing an approximated ear canal phase delay from AR data before fitting allowed for better comparison across ears, and better comparison with existing network models of the middle ear. Pole-zero fits indicated isolated regions of individual variation for normal ears, and showed differences between normal and pathological ears. Pole-zero fitting shows promise for more quantitative, robust diagnosis of middle ear pathology than AR magnitude alone.
Structural acoustic optimization of ribbed panels excited by complex forcing functions
Authors: Shepherd Micah R. , Hambric Stephen A.
Published: September 2012

Structural acoustic optimization is performed on a ribbed panel exited by diffuse acoustic field and turbulent boundary layer (TBL) flow. In order to vary the rib location during the optimization, component mode synthesis (CMS) was used with the rib and plate treated as separate substructures. The CMS approach couples the individual modes of the rib and plate using impedances at the connection points thus only requiring full eigenanalysis and radiation resistance calculations once and allowing for more rapid function evaluation during the optimization. The optimization was then performed using an evolutionary strategy with covariance matrix adaption. The rib location and properties were varied by the optimizer to find the best low-noise panel. An exhaustive search was performed to verify the optimum solution and compare results for several objective functions. Alternative design variables and constraints will also be discussed.
Inverse acoustic source identification in a massively parallel finite element framework
Authors: Walsh Timothy , Aquino Wilkins , Ridzal Denis , Young Joe
Published: September 2012

Characterizing the frequency spectrums of acoustic sources from measured accelerometer or microphone data is a common inverse problem in engineering acoustics. Applications include acoustic testing of aerospace structures, room acoustics, and underwater acoustics. Typically, accelerometer or microphone pressures are measured, and it is desired to characterize the acoustic sources that produced these measurements. Many of these applications of interest involve large acoustic domains and high frequency ranges, thus making a finite element solution an attractive option for the forward problem. In this talk we will present a partial differential equation (PDE) constrained optimization approach for solving the inverse problem that is based on a coupling between a finite element-based massively parallel structural dynamics code (Sierra-SD) and a massively parallel optimization code (Rapid Optimization Library (ROL)). Gradients and solution iterates are exchanged between the codes during the solution process. The gradients for the optimization solver are computed using the adjoint method, which translates to forward and adjoint Helmholtz solves in the frequency domain. We will present results on several problems of interest. Sandia is a multiprogram engineering and science laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the US Department of Energy's National Nuclear Security Administration. (DE-AC04-94AL85000)
Effects of articulatory planning factors on children's production of plural -s
Authors: Theodore Rachel M. , Demuth Katherine , Shattuck-Hufnagel Stefanie
Published: September 2012

Children’s early use of grammatical morphemes is notoriously variable. Recent findings indicate that some variability in early productions is systematically related to speech planning factors, suggesting that variability in morpheme production is not solely the consequence of impoverished syntactic representations. For example, research has shown that plural -s is produced more reliably in utterance-final compared to utterance-medial position. Here we examined the locus of the positional effect for plural -s . Productions of eight plural nouns in utterance-medial and utterance-final position were elicited from three groups of 2-year-olds. Across the groups, we manipulated articulatory difficulty of the medial context such that it consisted of a stop consonant (e.g., dogs bark), a stressed vowel (e.g., dogs eat), or an unstressed vowel (e.g., dogs arrive). Results showed a robust positional effect for the difficult context created by the stop consonant. The positional effect was not observed for the simple articulatory context created by the stressed vowel. However, planning difficulty for the unstressed vowel was sufficiently increased such that the positional effect again emerged in this context. These results suggest that production of grammatical morphemes is influenced by articulatory planning factors, which points to specific constraints for theoretical accounts of language acquisition.
Linguistic effects on the timing of gestural coordination in Modern Greek consonant clusters
Authors: Yip Jonathan C.
Published: September 2012

Although position in word, order of place of articulation, and manner of articulation have been shown to influence gestural timing in CC clusters in various languages, there is no consensus on whether these timing patterns are due to biomechanical or perceptual-recoverability constraints (or both) on production. This study of Modern Greek speakers’ CC productions investigates the effects of within-word position (initial, medial), place order (front-to-back, back-to-front), C1 manner (plosive, fricative), and C2 manner (plosive, fricative, liquid) on articulatory lag between C1 and C2. A perception-oriented account predicts an influence of both C1 and C2 manner on gestural lag when acoustic masking is most likely (i.e. when CC is word-initial and back-to-front), whereas a biomechanical account predicts no such effect. To assess relative degree of gestural lag, ultrasound imaging and lip video are used to track the timing patterns of labial, tongue-tip, and tongue-dorsum constrictions during production. Preliminary data on word-initial CC sequences show clear gestural onset lag and achievement lag in [kt] relative to [ks] and [kl], but no onset or achievement lag in [pt] relative to [ps] and [pl], consistent with the perceptual-recoverability hypothesis.
Prosodic position effects on the statistical relationships between distinctive features and acoustic-phonetic properties of English consonants
Authors: Silbert Noah H. , de Jong Kenneth J. , Regier Kirsten , Albin Aaron
Published: September 2012

Previous research has shown that distinctive features must interact extensively to account for the location and shape of phonological consonant categories in multidimensional acoustic space (de Jong, et al., 161st ASA Meeting). The current analysis focuses on how syllable position (onset vs. coda) modulates feature interactions in the consonants /p, b, t, d, f, v, s, z/. Statistical model comparisons indicate that models allowing pervasive interactions between features and syllable position fit better than do more restrictive models with few or no interactions. Some interactions between syllable position and features are well-documented, such as vowel duration distinguishing voicing more robustly in coda position than in onset position. Other such interactions are novel. For example, consonant duration can cue both voicing and manner contrasts, with duration differences corresponding more strongly to manner contrasts in onset position and more strongly to voicing contrasts in coda position. Similarly, measures of noise power distinguish coronals from labials in onset position, whereas place and voicing interact in codas. These results contribute to a picture of the acoustic distribution of consonants being not only segment-specific, but also determined substantially by the position of the consonant within a syllable.
Phonetic effects of distance in Burmese
Authors: Butler Becky
Published: September 2012

This study investigates the phonetic effects of distance from phonological boundaries. Burmese, a Sino-Tibetan language, has a set of words of the shape Cə.Cə.(CV), in which the last syllable is footed, may contain any vowel in the inventory, and carries tone; whereas unfooted syllables contain only the vowel [ə] and do not have lexical tone (Green 1995, 2005). Under a purely phonological interpretation, we may expect all unfooted syllables to be identical in terms of duration and vowel quality. However, Chitoran and Hualde (2007) show that for Romance languages, distance from stress - a phonological entity - can cause significant durational differences between pretonic and pre-pretonic vowels. Similarly, the present study finds that although formant values between prefooted and pre-prefooted vowels in Burmese are not significantly distinct for any speakers - suggesting that vowel quality in all unfooted syllables is similar - distance from the tone-bearing syllable causes significant durational differences for three of five speakers (p < 0.0001). These results suggest that the data can be explained by neither phonological categorality nor phonetic gradience alone, but that both play a role in speech production and that the importance of each varies across speakers.
Acoustic and aerodynamic characteristics of nasal diphthongs in Brazilian Portuguese
Authors: Demasi Rita , Demolin Didier
Published: September 2012

Previous studies describe acoustic and aerodynamic aspects of nasalized vowels in Brazilian Portuguese. However, there are few studies characterizing nasal diphthongs in this language. The aim of this work is to analyze acoustic and aerodynamic characteristics of nasal diphthongs of Brazilian Portuguese spoken in the city of São Paulo. We compared oral and nasal diphthongs to identify the main features of these sounds and to understand the timing of velum movements. Our data was recorded with the Portable EVA 2 workstation. The corpus of this experiment was made of ten oral and ten nasal diphthongs, with back and front glides at the end: /aw/ and /ej/; /ãw̃/ and /ẽj̃/. Words were inserted in the following sentence [i.gʊ___kadɐ iɐ] and [i.gʊ___todʊ iɐ]. The first phrase was repeated three times with six subjects and the second with three subjects. The corpus was analyzed with the Signal Explorer and Phonédit Softwares. The aerodynamic parameters analyzed were duration, peak and volume of nasal airflow. The acoustic parameters analyzed were formants patterns and FFT spectrum. Aerodynamic and acoustic data show that in nasalized diphthongs, the nasalized vowel is followed by a nasal glide and a short nasal appendix. The peak of nasal airflow at the end of the nasal diphthong is due to the fact that the oral closure, which is made for the following voiceless stop, is produced with an open velum.
Hierarchical Bayesian modeling of vowel formant data: Speaker-intrinsic and speaker-extrinsic approaches compared
Authors: Albin Aaron L. , Rankinen Wil A.
Published: September 2012

Vowel formant data is traditionally normalized across speakers by transforming a set of ‘raw’ measurements into ‘standardized’ ones in one of two ways. With a speaker-extrinsic method, data from each individual is normalized with respect to external baseline measures calculated across the population of all speakers in a corpus, whereas a speaker-intrinsic method normalizes entirely with respect to speaker-dependent variables. The present study reports on implementations of both these methods in terms of hierarchical statistical models whereby probability distributions for various model parameters can be obtained using Bayesian analysis (rather than merely ‘converting’ the measurements). In this new framework, a speaker-extrinsic approach can estimate (1) the size and shape of each speaker’s vowel space, (2) the locations of vowel categories across a speech community within a normalized space, and (3) individual speakers’ deviations from the community norms. However, this process relies on a number of assumptions that are not needed with a speaker-intrinsic approach, which instead makes many low-level discrete ‘decisions’ on a speaker-by-speaker basis. By testing multiple models on the same dataset (a large corpus of vowel data collected from 132 speakers of American English), the present study explores the comparative merits of speaker-extrinsic and speaker-intrinsic Bayesian models.
The effect of physical appearance and accent on the elicitation of vowel hyperarticulation by British English native speakers in speech to foreigners
Authors: Kangatharan Jayanthiny , Uther Maria , Gobet Fernand
Published: September 2012

Speech aimed at infants and foreigners has been reported to include the physical exaggeration of vowels, that is vowel hyperarticulation. Although infants have been demonstrated to experience hyperarticulated vowels in speech directed at them, little research has been done on whether vowel hyperarticulation occurs as a result of foreign appearance, foreign accent or as a consequence of both looking and sounding foreign. The present study explored if appearance and speech separately affect the native speakers’ hyperarticulation. Fifty-two White British adult speakers communicated with one of four different confederate groups (2 types of appearance x 2 types of accent) to solve three modified versions of the DiapixUK tasks. Results indicate that not appearance but speech had an effect on native speakers’ production of vowels. Specifically, vowel space was significantly larger in speech directed to foreign-accented individuals than to individuals with native accent irrespective of their physical appearance. The acquired samples of hyperarticulatory speech will be used in perceptual identification and clarity tasks to ascertain which speech samples help native speakers to understand speech better.
Relationship between articulatory acoustic vowel space and articulatory kinematic vowel space
Authors: Lee Jimin , Shaiman Susan
Published: September 2012

The current study examines the relationship between articulatory acoustic vowel space and kinematic vowel space with an emphasis on the range of tongue movement by utilizing electromagnetic articulography. Subject population is 20 healthy female speakers. Electromagnetic articulography (AG-200) and a synchronized separate digital audio recording system were utilized to obtain kinematic and high quality acoustic data. Three coils on the tongue (tip, body, and dorsum) and one coil on the lower lip were used. To examine both intra- and inter- speaker relationship between articulatory acoustic and kinematic spaces, speech samples of ten different tasks that elicited various articulatory space sizes were collected. Each speaker produced three repetitions of four corner vowels in /h/-vowel-/d/ and /d/-vowel-/d/ consonant environments embedded in a carrier phrase in five different speaking styles (habitual, fast, slow, loud, and soft). Articulatory working space was generated from coordinates of first and second formant frequencies from acoustic data, and position X and Y from each coil kinematic data. Both acoustic and kinematic coordinate data are obtained at the same time sampling point. Results will be discussed in terms of amount of variance of acoustic vowel space explained by kinematic articulatory space and issues of interpretation of acoustic vowel space.
Predictability effects on vowel realization in spontaneous speech
Authors: McAuliffe Michael , Babel Molly
Published: September 2012

Previous research on vowel realizations within the formant space has found effects for lexical factors such as word frequency in both laboratory settings (Wright, 2004; Munson & Solomon, 2004; and others) and in spontaneous speech (Gahl, Yao, & Johnson, 2012). In addition to lexical factors, semantic context has also been found to influence vowel realizations in laboratory settings, such as emphatic/non-emphatic contexts (Fox & Jacewicz, 2009) and whether a word is predictable from the preceding words (Clopper & Pierrehumbert, 2008). The current project looks at whether effects on vowel realization for semantic context from the laboratory can be extended to spontaneous speech. As in Gahl, Yao, and Johnson (2012), the Buckeye Corpus (Pitt et al., 2007) will be used, with the same predictors used there with the addition of a semantic predictability measure. Semantic predictability for a given word will be calculated based on relatedness of that word to words five seconds before the word or less, where relatedness will be calculated based on WordNet (Princeton University, accessed 2012). As a listener can rely more on context for disambiguation, words that are predictable from their preceding context are hypothesized to contain less distinct vowels than words that are not predictable from context.
Acoustic and physiologic measures of register transitions sung by females
Authors: Morris Richard J. , Okerlund David , Dolly Claire E.
Published: September 2012

The purpose of this study was to examine the physiological and acoustical adjustments made by trained female singers to transition across vocal registers when singing a chord triad. Ten female singers participated in this study. A microphone was placed 30 cm from the corner of the subjects mouth and EGG electrodes were positioned over their thyroid laminae. Audio and EGG signals were channeled to Voce Vista Pro software. Each singer was presented the starting pitch of A3 or 220 Hz, by the experimenter and directed to sing a chord triad using an [a:] vowel. Each triad was sung in a single breath at an andante tempo. The EGG measurements included the closing quotient (CQ) and the FFT spectrum measurements include the harmonic number, frequency, and amplitude of the harmonic with the greatest amplitude. Four singers lowered CQ, two raised CQ, and four maintained a steady CQ when changing vocal register. The frequencies and amplitudes of the peak harmonic remained fairly steady across the register shift. These changes indicated that the singers were tracking their vocal tract resonance to their CQ. The more trained singers used the third harmonic in their chest register and the second harmonic in middle register.
The effect of segmental makeup on Mandarin tone coarticulation
Authors: Lai Yuwen , Huang Hui-Ting
Published: September 2012

The effect of segmental make-ups on tonal coarticulation was investigated in Mandarin. Target syllables differ in coda (no coda, alveolar nasal or velar nasal) and initial sonorancy (obstruent or sonorant) were embedded in trisyllabic non-words templates, in the form of trisyllabic names. Twenty native speakers were recorded and the F0 contours of all syllables were measured at a 10-ms time step. The coarticulation effect of four Mandarin tones are examined in three different positions with 4 (initial position), 16 (medial position), and 4 (final position) tonal contexts. Moreover, the phonetic variations of each tone in different prosodic positions were examined. The preliminary results indicate that the coarticulation effect is less prominent when intervened by obstruents whereas nasal codas amplify the effect. The realization of this modulating effect on the directionality of tonal coarticulation (carryover and anticipatory) will be discussed. The magnitude of coarticulation in compatible (adjacent tones have similar registers) and conflicting (adjacent tones with large register difference) environments will also be compared.
Acoustic differences in adult-directed and child-directed monosyllabic Mandarin tone productions
Authors: Wong Puisan , Yu Xin , Zhang Guanjin , Zhu Jiulin , Yeung Tina
Published: September 2012

To investigate the acoustic differences in adult- and child-directed monosyllabic Mandarin tone productions, twenty-one mothers of preschool children labeled pictures that represented monosyllabic words to their children and to another adult. Their productions were low-pass filtered to eliminate lexical information. Five judges determined the target tones based on the filtered stimuli. Acoustic analyses were performed on the productions in which the target tones were correctly identified by four or more of the judges. Preliminary results showed no duration difference in the four tones in adult-directed and child-directed productions. Overall, all the four tones were produced at significantly higher f0s in child-directed productions than in adult-directed productions. Specifically, child-directed Tone 1 productions were produced at significantly higher f0s, and the f0 contours exhibited higher positive f0 slopes and were not as level as in adult-directed Tone 1 productions. Child-directed Tone 2 productions were produced at higher f0s, spanned at larger f0 ranges but maintained the same rising slopes as in adult-directed productions. Child-directed Tone 3 and Tone 4 productions had the same f0 shapes as in adult-directed productions but were produced at higher f0s (Work supported by NIDCD).
Perception and production of Mandarin tones by English vocalists and instrumentalists
Authors: Lu Shuang , Kirkham Joe , Wayland Ratree , Kaan Edith
Published: September 2012

Musical training has been found to positively affect non-native lexical tone perception and production (e.g. Wong et al., 2007). While there are comprehensive studies on trained instrumental musicians, relatively little is known about formally trained vocal musicians. The present study compares English vocalists and instrumentalists to see which type of musical training is more advantageous to lexical tone perception and production. Stimuli consisted of six syllables ([thi], [li], [mi], [tho], [lo], [mo]) associated with four Mandarin tones (high-level, high-rising, low dipping, and high falling). Native Mandarin non-musicians, native English non-musicians, vocalists, and instrumentalists (n =15 per group) were tested in a same/different discrimination task and an imitation task. In the discrimination task, the English vocalists [d’ = 3.12] performed significantly better than the English non-musicians [d’ = 2.41; p = 0.04]. The vocalists also numerically outperformed the instrumentalists [d’ = 2.84], who in turn outperformed the English non-musicians. Analyses on the “different” and “same” tone-pairs showed that the vocalists are marginally more accurate than the instrumentalists for T2-T2 pair-type only [p = 0.067]. In the imitation task, the three English groups did not differ in how their productions were evaluated by the native Mandarin judges.
Prosodic characteristics of three sentence types in Thai
Authors: Silpachai Alif
Published: September 2012

This study presents an acoustic analysis of three sentence types in Thai (declarative, interrogative, and emphatic) with the goal of providing a basic characterization of their prosody. To investigate prosodic realizations of sentence final syllables, we placed, in a sentence-final position, a target word which varied in one of the 5 lexical tones in Thai. We also varied the tonal context before the target word so that the pre-target word ends with low (21), mid (31), or high (45) tones. Preliminary results from one speaker show that F0 measures, especially f0 maximum, minimum, and range, differed across sentence types. In particular, emphatic sentences were distinguished from non-emphatic sentences by expanded F0 range, whereas target words in questions were distinguished from those in declarative sentences by both higher F0 maximum and minimum. Syllable duration also played a role in signaling emphasis and question: emphatic sentences were significantly longer than non-emphatic sentences, and questions were significantly shorter than declarative sentences. Interestingly, the tonal pattern of the target word changed for the case of emphasis when the target word had 31 and 45 tones. We will present findings from four additional Thai speakers and discuss their relevance to the intonational phonology of Thai.
Brazilian Portuguese intonation: A comparison between automatic and perceptual analyses
Authors: Ferreira Netto Waldemar , Martins Marcus Vinicius Moreira , Peres Daniel Oliveira , Rosa Renata Cezar de Moraes , Medeiros Joice
Published: September 2012

The present work aims to determine the most appropriated automatic analysis of phrasal intonation patterns in Brazilian Portuguese, understood as the variation of F0. In order to evaluate the automatic analysis done by the software ExProsodia a perceptual analysis was carried out and its results were compared to the ones given by the software. The corpus consisted of one sentence produced three times by 11 female subjects. In the perceptual analysis an intuitive evaluation was done considering the syllabic nuclei as intonation units (control group). The data from the automatic analysis were analyzed in three different ways: i) the cumulative mean of all points of intonation curve; ii) the cumulative mean of points higher than 0Hz; iii) and the cumulative mean of the points selected by ExProsodia. The acoustic parameters considered for the automatic analysis were: F0- from 50Hz to 700Hz; duration- from 20ms to 600ms; intensity- higher than 10% of RMS mean of intonation curve. A Dunnett's test compared the control group with other groups from the automatic analysis (α = 95%, n = 33). In the comparison between the control group and i & ii, it was obtained p < 0.05. It was verified that the units established by the interval given by ExProsodia (iii) were the only ones that showed no significant differences when compared to the control group. The results indicate a similarity between the automatic and perceptual analyses. The automatic analysis done by ExProsodia seems thus trustworthy.
Language grouping based on pitch interval variability
Authors: Stojanovic Diana
Published: September 2012

Language rhythm has been discussed so far as a consequence of regularity, phonological differences, and in most recent literature as a result of durational variability. Original support coming from perception experiments is recently often questioned at least in terms of how well listeners can classify language samples stripped of all but durational information. In particular, pitch has been suggested to play a significant role in perceiving rhythmic differences. In Patel 2006, language and music rhythm differences between English and French were measured by means of durational and melodic measures. It was shown that the variability of pitches did not distinguish between two languages, but the variability of pitch excursions was significant. In this paper, we use pitch excursion variability as a measure applied to read samples of several languages. Preliminary results on 30 sec samples show that Brazilian Portuguese, French, Hawaiian, and Indonesian group together compared to English and German. The first group has more frequent but less prominent excursions (60 Hz) while the second group has less frequent but larger excursions (100Hz). Based on these results, originally proposed regularity can at least partly be explained by the variability of pitch intervals, grouping languages into “smooth” vs. “more prominent”.
Discriminating languages with general measures of temporal regularity and spectral variance
Authors: Carbonell Kathy M. , Brenner Dan , Lotto Andrew J.
Published: September 2012

There has been a lot of recent interest in distinguishing languages based on their rhythmic differences. A common successful approach involves measures of relative durations and duration variability of vowels and consonants in utterances. Recent studies have shown that more general measures of temporal regularities in the amplitude envelope in separate frequency bands (the Envelope Modulation Spectrum) can reliably discriminate between English and Spanish [Carbonell et al. J. Acoust. Soc. Am. 129, 2680.]. In the current study, these temporal structure measures were supplemented with measures of the mean and variance of spectral energy in octave bands as well as with traditional linguistic measures. Using stepwise discriminant analysis and a set of productions from Japanese, Korean and Mandarin speakers, this suite of both acoustic and linguistic measures were tested together and pitted against each other to determine the most efficient discriminators of language. The results provide insight into what the traditional linguistic measures of speech rhythms are telling us about how language type structures the acoustic signal.
Phonetic characteristics of syllable reduction and enhancement in American English
Authors: Tajima Keiichi , Shattuck-Hufnagel Stefanie
Published: September 2012

Syllables have been argued to play an important role in the prosodic organization of spoken language, but the number of syllables that speakers produce or listeners hear in an utterance is not always clear-cut, and may vary in subtle ways. For example, speakers may reduce or delete unstressed vowels in casual speech, e.g., producing support as s’port, on one hand, or insert vowels in careful speech, e.g., producing please as puh-lease, on the other. Relatedly, duration differences in a non-vowel segment may lead to changes in word identity based on the presence/absence of an unstressed vowel, as when different durations of /l/ in blow are sufficient to lead listeners to perceive either blow or below. The present study investigates how often such apparent changes in syllable count occur in spoken English, which phonetic contexts they tend to occur in, and to what extent these changes are probabilistic, by analyzing productions from a phonetically annotated corpus of conversational American English. Preliminary results suggest that unstressed vowels are often reduced enough to be omitted from the transcription, and this occurs more in certain phonetic contexts than others. Further results, and implications for theories of speech production and perception, will be discussed. [Work supported by JSPS.]
Acoustic contrastivity in soft, conversational, and loud speech
Authors: Kim Yunjung , Beslin Ali
Published: September 2012

Increasing vocal effort is frequently used in clinical practice as a strategy to enhance speech intelligibility of individuals with various speech problems, particularly dysarthria. However, it is not straightforward why this strategy might yield better speech intelligibility, although some potential contributors have been suggested including hyperarticulation of vowels, greater presentation level of sounds (for consonant identification accuracy) or both. This presentation focuses on the change of relative contrastivity within utterances that were produced with gradually increasing vocal efforts (soft, conversational and loud, see Kim, ASA, 2011) to examine whether acoustic contrastivity is exaggerated with increasing vocal intensity and to identify the acoustic variables that produce contrastivity that are more or less sensitive to changes in vocal intensity. In this presentation, data on the ratio of vowel durations (long vs short), formant structures of vowels (tense vs lax) as well as the ratio of M1 of /s/ vs /∫/ will be compared across soft, conversational and loud speech conditions produced by young female adult speakers.
Cross-correlations of diffuse ocean noise using eigenvalue based statistical inference
Authors: Menon Ravi , Gerstoft Peter , Hodgkiss William S.
Published: September 2012

Cross-correlations of diffuse noise fields can be used to extract environmental information. The influence of directional sources (usually ships), often results in a bias of the travel time estimates obtained from the cross-correlations. Using an array of sensors, insights from random matrix theory on the behavior of the eigenvalues of the sample covariance matrix (SCM) in an isotropic noise field are used to isolate the diffuse noise component from the directional sources. A sequential hypothesis testing of the eigenvalues of the SCM reveals eigenvalues dominated by loud sources that are statistical outliers for the assumed diffuse noise model. Travel times obtained from cross-correlations using only the diffuse noise component (i.e., by discarding or attenuating the outliers) converge to the expected travel times (i.e., unbiased estimates) and are stable temporally. Data from the Shallow Water 2006 experiment demonstrates the effectiveness of this approach and that the SNR builds up as the square root of time, as predicted by theory.
Computational model for the eigenvalue density function of a cylindrically isotropic noise sample covariance matrix
Authors: Tuladhar Saurav R. , Buck John R. , Wage Kathleen E.
Published: September 2012

Adaptive beamformers (ABFs) rely on the knowledge of ensemble covariance matrix (ECM), which is usually not known a priori. The ECM is often estimated from the sample covariance matrix (SCM). When the sample size is limited, the SCM may not converge to the ECM. ABF performance is then determined by the SCM eigenstructure. Random Matrix Theory (RMT) provides a helpful framework to analyze the asymptotic behavior of the SCM eigenstructure. This talk presents a computational model for the SCM's asymptotic eigenvalue density function (EDF) for a uniform linear array in a cylindrically isotropic noise field. Cylindrically isotropic noise fields are common models for shallow water environments, including the Kuperman-Ingenito noise model. The proposed method employs Nadakuditi and Edelman's polynomial method to model the EDF as the product of a deterministic matrix and a Wishart matrix. The model exploits properties of free multiplicative convolution to reduce the required polynomial order, resulting a substantial computational savings. The model EDF exhibits good agreement with eigenvalue histograms from simulations. A model for the SCM EDF is a necessary first step for accurate bearing dependent detection thresholds in cylindrically isotropic noise environments. [Supported by ONR.]
High-frequency hearing in seals and sea lions and the implications for detection of ultrasonic coded transmitters
Authors: Cunningham Kane A. , Hayes Sean A. , Rub Michelle W. , Reichmuth Colleen
Published: September 2012

In order to better understand the ability of pinnipeds to detect acoustic signals from ultrasonic coded transmitters (UCTs) commonly used in fisheries research, high-frequency hearing thresholds were obtained from a trained Pacific harbor seal (Phoca vitulina) and a trained California sea lion (Zalophus californianus). Using a 69 kHz, 500 ms, narrow-band FM sweep stimulus, detection thresholds for the harbor seal and the sea lion were determined to be 106 dB and 112 dB re 1 μPa respectively. While the harbor seal threshold falls within the range of existing data, the sea lion threshold is 33 dB lower than expected based on previous reports. This finding indicates that sea lions may be more sensitive to the output of UCTs than previously thought, and allows for the possibility that acoustically tagged fish may be selectively targeted for predation by sea lions as well as seals. These hearing thresholds, combined with ongoing work on the effect of signal duration on high-frequency hearing, will help estimate the ranges at which certain UCTs can be detected by these species. Detection range estimations, in turn, will allow fisheries researchers to better understand how fish survivorship data obtained using UCTs may be skewed by pinniped predation.
Comparison of the first-year response of beaked and sperm whale populations to the Northern Gulf oil spill based on passive acoustic monitoring
Authors: Sidorovskaia Natalia , Ackleh Azmy , Tiemann Christopher , Ioup Juliette , Ioup George
Published: September 2012

This paper continues a discussion on using passive acoustic methods to study the environmental impact of the recent oil spill in the Northern Gulf of Mexico on resident populations of marine mammals. The Littoral Acoustic Demonstration Center, possessing several broadband acoustic datasets collected near the spill site before and after the event, is in a unique position for monitoring long-term environmental impacts in the vicinity of the incident The pre-spill recordings provide a baseline which, when combined with post-spill measurements, give important indicators of changes in the local populations. Ackleh et al., J. Acoust. Soc. Am. 131, 2306-2314, provide a comparison of 2007 and 2010 measurements showing a decrease in acoustic activity and abundance of sperm whales at the 9-mile distant site, whereas acoustic activity and abundance at the 25-mile distantsite has clearly increased. This may indicate that some sperm whales have relocated farther away from the spill subject to food source availability. This paper reports on applying developed population estimation techniques to monitor beaked whale response that appears to be different from that of sperm whales. Follow-up experiments will be critical for understanding the long-term impact on different species. [Research supported by SPAWAR, NSF, and Greenpeace.]
Population density of sperm whales in the Bahamas estimated using non-linked sensors
Authors: Küsel Elizabeth T. , Mellinger David K. , Thomas Len , Marques Tiago A.
Published: September 2012

Estimates are presented of sperm whale click detection probability and sperm whale population density at the U.S. Navy’s Atlantic Undersea Test and Evaluation Center (AUTEC) in the Bahamas. The estimation of the probability of detecting whale echolocation clicks at multiple non-linked sensors uses estimates of sperm whale source level distribution, beam pattern of click emission, distribution of whale locations and orientations with respect to the sensors while clicking, acoustic transmission loss from source (whale) to receiver (bottom hydrophone), and noise levels at the receiver. These data are combined in a Monte Carlo model that propagates simulated clicks from whales at various random positions to each receiving hydrophone to estimate the signal-to-noise ratio at the receiver and the detection function, the probability of detecting clicks as a function of distance. The estimated detection function for each receiving hydrophone is then combined with information on the detector’s rate of missed calls and false detections as a function of signal-to-noise ratio, average sperm whale click rates, and the actual number of clicks detected in a given period of time in order to estimate population density. Results are compared to multi-sensor cases where detection functions were estimated analytically.