bluuebunny/crossref_metadata_2025 huggingface dataset:
Collecting population statistics: The discriminant power of clicks
Authors: Gold Erica
Published: October 2011

This research gathers population statistics on clicks for use in likelihood ratios (LRs). As reported in Gold and French (2011), clicks have been analyzed by 57% of experts in forensic speaker comparison cases and 18% of experts find them to be useful speaker discriminants. Eight minutes of speech from 100 male speakers of Southern Standard British English were analyzed from the DyVis Database, using categorical annotations of clicks (Wright, 2007). The distribution of click use in subjects is highly skewed with a large majority not clicking. However, the distribution of clicks is highly variable with non-clickers ranging from 25–44% of the population depending on the length of the speech sample. The same 100 speakers were also analyzed for click use when speaking with two additional interlocutors. Again the results are highly variable, which suggests the intra- and inter-speaker instability of clicks, the lack of overall robustness, and the accommodation of clicks in speech. This study serves as a beginning point in incorporating previously unreported population statistics into LRs, and specifically examining the potential of including higher order and paralinguistic features in a Bayesian framework. [Research funded by the European Community's Seventh Framework Program (FP7/2007-2013) under grant agreement #238803].
Dispersion and variability of vowels of different inventory sizes
Authors: Lee Wai-Sum , Zee Eric
Published: October 2011

This study investigates dispersion and variability in the vowels of systems with different phonemic inventory sizes in three Chinese dialects. Yongding Hakka, Hong Kong Cantonese, and Wenling Wu have three, seven, and eleven vowel phonemes, respectively. Measurements of formant frequencies were obtained through a spectral analysis of speech data from twenty male and twenty female speakers of each dialect. Results show that the size of acoustical vowel space in the F1F2 plane increases with an increase in vowel inventory size. The finding supports the vowel dispersion theory (Lindblom, 1968; Liljencrants and Lindblom, 1972) which claims that the larger the inventory is, the more expanded the vowel space will be. However, the prediction by the theory that variability in vowel formants is inversely related to the vowel inventory size is not supported by the vowel formant data from the three Chinese dialects. In Fant (1966, 1975), female vowels are said to exhibit greater between-category dispersion in the F1F2 plane than male vowels. The observation is supported by the vowel formant data from the three Chinese dialects. However, this is true before vowel normalization, but not after. Lastly, no gender-related patterning of vowel dispersion is observed in the three Chinese dialects.
Effects of speaking rate, sentential position, and coda voicing on formant frequency
Authors: Evanini Keelan , Ko Eon-Suk
Published: October 2011

This study examines the effects of speaking rate, sentential position, and coda voicing on formant frequency values in English. Some previous studies have found gestural undershoot for formant target values in words with shorter durations, e.g., Lindblom (1963), although other studies have shown little to no effect of duration, e.g., Gay (1978), and the effects of the other factors are less-studied. This study examines formant frequencies of three different vowels (/i/, /e/, and /ae/) in CVC words containing both voiced and voiceless codas produced in three different sentence positions (initial, medial, and final) and three different speaking rates (slow, habitual, and fast). In total, seven speakers (five female and two male) of the Northern dialect of American English produced 1295 tokens, and vowel formant measurements were extracted at 1/3 of the duration of each vowel token. Separate linear regression analyses of the three vowels for the male and female speakers show that F1 and F2 target values do not vary systematically with vowel duration. In many cases, however, sentence position and coda voicing do have significant effects: in general, F1 and F2 values are more peripheral before voiced codas and in sentence-initial position.
Three-dimensional underwater sound propagation using a split-step Padé parabolic equation solution
Authors: Collis Jon M.
Published: October 2011

The majority of current three-dimensional (3-D) parabolic equation propagation model development work has been focused on implementations. Recent attention has been on the modeling of internal wave fields and propagation in the presence of strong internal tides and eddies. State of the art solutions are experimental water-tank comparisons against azimuthal schemes [Sturm etal., JASA 113] and split-step Fourier based propagation models [Lin etal., JASA 126]. A current thrust is to establish 3-D benchmarks for propagation simulations in range-dependent environments where effects due to generic bottom features are present. In this paper, a 3-D extension to current 2-D split-step Padé solutions is developed and benchmarked. Transverse and depth operator discretizations are performed using a Galerkin method. Cartesian versus cylindrical coordinate systems are discussed as is the nature of the acoustic source in either geometry.
Human error rates for speaker recognition
Authors: Shen Wade , Campbell Joseph P. , Schwartz Reva
Published: October 2011

It is commonly assumed that speaker identification by human listeners is an innate skill under certain conditions. As such, human listening tests have served as the benchmark for automatic recognition systems. In recent evaluations comparing human and machine performance on a speaker comparison task, error rates of naïve human listeners far exceed those of machines [special session on Human Assisted Speaker Recognition, IEEE ICASSP, Prague, 2011]. In this presentation, we quantify the performance of naïve listeners in a variety of challenging channel conditions and we compare these results against automatic systems and trained human listeners. The results of these experiments impact the admissibility of both forensic voice analysis and courtroom testimony by human listeners.
Progress toward a forensic voice data format standard
Authors: Wayman James L. , Campbell Joseph P. , Torres-Carrasquillo Pedro , Higgins Peter T. , Martin Alvin , Nakasone Hirotaka , Greenberg Craig , Pryzbocki Mark
Published: October 2011

The de facto international standard for the forensic exchange of data for biometric recognition is ANSI/NIST ITL-1/2, “Data Format for the Interchange of Fingerprint, Facial, and Other Biometric Information.” This format is used by law enforcement, intelligence, military, and homeland security organizations thoughout the world to exchange fingerprint, face, scar/mark/tatoo, iris, and palmprint data. To date, however, there is no provision within the standard for the exchange of audio data for the purpose of forensic speaker recognition. During the recent 5-year update process for ANSI/NIST ITL-1/2, a consensus decision was made to advance a voice data format type under the name “Type 11 record.” Creating such an exchange format type, however, is far from straight forward—the problem being not the encoding of the autio data, for which many accepted standards exist, but rather in reaching a consensus on the metadata needed to support the varied mission requirements across the stakeholder communities. In this talk, we'll discuss the progress that has been made to date, the questions that remain, and the requirements for additional input from the broader stakeholder communities.
Development of speech motor control: Lip movement variability
Authors: Lfqvist Anders , Frid Johan , Schötz Susanne
Published: October 2011

This study examined variability of lip movements across repetitions of the same utterance as a function of age in Swedish speakers. Subjects were 37 typically developed Swedish children and adults (19 females, 18 males, aged 5–31 yr). Lip movements were recorded during 15–20 repetitions of a short Swedish phrase using articulography, with a sampling rate of 200 Hz. After correction for head movements, the kinematic records were expressed in a maxilla-based coordinate system. Movement onset and offset of the utterance were identified using kinematic landmarks. The Euclidean distance between receivers on the upper and lower lips was calculated and subjected to functional data analysis [Ramsay etal., J. Acoust. Soc. Am. 99, 3718–3727 (1996)] to assess both temporal and spatial variabilities. Results show a decrease in both indices as a function of age, with a greater reduction of amplitude variability. [Work supported by grant 349-2007-8695 from the Swedish Research Council.]
Imaging and quantification of glottal kinematics with ultrasound during speech
Authors: Parrell Benjamin , Lammert Adam , Goldstein Louis , Byrd Dani , Narayanan Shrikanth
Published: October 2011

Most examinations of glottal abduction and adduction during speech have employed laryngoscopic video or transillumination (Hoole, 2006). While these provide accurate information about timing of glottal movements, they are invasive and cannot provide absolute measurements about glottal width. At the same time, recent medical studies have used ultrasonic imaging to accurately capture glottal movements and laryngeal anatomy [Hu, J. Ultrasound Med. (2010); Jadcherla etal., Dysphagia (2006)]. We demonstrate novel methods of using ultrasound to measure both temporal and spatial aspects of glottal movements during speech. While previous work on glottal ultrasound has been limited by the need to manually analyze each acquired frame, we present methods to automatically quantify glottal aperture in ultrasound images. Finally, since glottal ultrasound does not interfere with the acquisition of supra-laryngeal articulatory data, we present the results of preliminary experiments that record laryngeal and supra-laryngeal speech movements simultaneously using ultrasound concurrently with electromagnetic articulometry. This allows the analysis of relative timing between movements in the two systems as well as examination of changes in timing or magnitude due to variables such as prosodic structure or speech rate. [Work supported by NIH.]
The scope of phrasal lengthening: Articulatory and acoustic evidence
Authors: Riggs Daylen , Byrd Dani
Published: October 2011

The temporal lengthening that occurs at phrase edges is known as phrasal lengthening. The scope of phrasal lengthening refers to the distance both before and after a phrase edge that phrasal lengthening can occur. This paper examines the influence of prosodic prominence on the scope of phrasal lengthening in articulation. Pitch accent was placed immediately adjacent to the phrase edge and at varying distances before and after the phrase edge. Articulatory durations of gestures were measured in the pitch-accented syllables and in the syllables intervening between the phrase edge and the pitch-accented syllables. Acoustic measurements of consonant, syllable, and vowel duration were also examined. These constriction durations were compared to those for gestures in phonologically parallel control sentences that lacked a phrase boundary. The results indicate that phrasal lengthening is most systematic immediately adjacent to the phrase edge. However, pitch accent can attract phrasal lengthening. One subject showed phrasal lengthening in a pitch-accented syllable, three syllables away from the boundary. Finally, when the remote pitch-accented syllable showed phrasal lengthening, gestures intervening between the phrase edge and the pitch-accented syllable also showed phrasal lengthening. These patterns are evaluated in the context of the prosodic gestural model of Byrd & Saltzman (2003).
Can you say [v] or [x]? Aerodynamics of nasalized fricatives in Scots Gaelic
Authors: Brenner Daniel , Davis Andrea , Warner Natasha , Carnie Andrew , Fisher Muriel , Schertz Jessamyn , Hammond Michael , Archangeli Diana
Published: October 2011

Scots Gaelic is said to have nasalized fricatives ([ṽ, x̃, h̃] etc.). Nasalized fricatives may be aerodynamically impossible (except [h̃]), because opening the velum would vent the high oral pressure required for frication (Ohala 1975). However, phonologically nasalized fricatives which are realized some other way phonetically are possible, and [h̃] is possible because the frication occurs behind the velic opening. The current work presents oral and nasal airflow data from 14 native speakers of Scots Gaelic, primarily from the Skye dialect, to investigate the nasalized fricative distinction. Results indicate that the most common solution to the aerodynamic problem is to neutralize the distinction: most phonological nasalized fricatives, from most speakers, are simply not nasalized at all ([v] for [ṽ]. Some tokens show nasalization during the preceding vowel ([ãv] for [aṽ]). Some tokens in which the expected fricative is pronounced as an approximant (common in Scots Gaelic) show nasalization w̃ for [ṽ]). Furthermore, [h̃] occurs. Very rarely, there may be slight nasalization overlapping part of an oral fricative. Thus, the data show that conflicting aerodynamic demands are resolved variably: in this dialect, the distinction is usually neutralized; when it is not, several alternatives that avoid the aerodynamic conflict are produced.
An articulatory and acoustic investigation of Mandarin apical vowels
Authors: LEE SANGIM
Published: October 2011

The present study investigates the articulatory and acoustic properties of apical vowels in Mandarin Chinese using ultrasound and acoustic measures. Instead of the high front vowel, dental and retroflex sibilants are known to be followed by apical vowels made with tongue tip/blade, rather than the tongue body. The ultrasound images of one Beijing speaker confirmed that the tongue tip/blade gesture indeed remains unreleased during the production of these vowels. However, it also revealed that the tongue body for apical vowels is significantly retracted with a relative order of the vowel following dentals being more retracted than the vowel following retroflexes. This gave rise to a consistent acoustic consequence; the second formant of the vowel after dentals of six Mandarin speakers was significantly lower than that of the vowel after retroflexes. In addition, the third formant of the vowel after a retroflex was significantly lowered and nearly merged with the second formant, indicating that the vowel is also strongly retroflexed. The correct analysis is thus claimed to include the apical gestures as secondary features added to the main articulation of the tongue body as in the following notation: a dentalized back vowel and a retroflexed mid vowel.
Identifying relevant analysis parameters for the classification of vocal fold dynamics
Authors: Voigt Daniel , Eysholdt Ulrich
Published: October 2011

In the previous work, a computer-based analysis framework was proposed, which is capable of objectively and automatically classifying vocal fold vibrations as captured by high-speed videoendoscopy during phonation. The method is based on quantitative feature extraction from Phonovibrograms combined with nonlinear machine learning techniques, allowing for the discrimination of normal and pathological laryngeal movement patterns. The diagnostic reliability and potential of this analysis approach were demonstrated. However, the practically relevant question, whether certain control parameters of the procedure can lead to increased classification accuracy, remained partially unanswered. In this study, the following parameter sets of the analysis framework were investigated in a systematic manner: method of feature extraction, type of feature aggregation and normalization, number of considered oscillation cycles, feature laterality, classification task, and employed machine learning algorithm. For this purpose, more than 150 000 experiments were conducted using a data set of 105 laryngeal high-speed video recordings, comprising various clinical cases with non-organic findings and subjects from a healthy control group. The results of this extensive study show the particular suitability of certain parameter combinations, helping to further improve the practical application of the automated classification framework for vocal fold dynamics.
The prosodic structure of Koasati
Authors: Gordon Matthew , Langley Linda , Martin Jack
Published: October 2011

This paper presents results of the first systematic acoustic investigation of the prosodic system of Koasati, an endangered Muskogean language of Louisiana. Koasati is prosodically complex, featuring lexically marked pitch accents in nouns and verbs, as well as phonologically predictable pitch accents and boundary tones assigned by the intonational system. While most nouns are characteristically associated with a final F0 rise attributed to a phrase-level tone, some have an additional lexically marked high pitch accent on a non-final syllable. The pitch accent system in verbs is more intricate and consists of different types of aspectually determined accents (termed ‘grades’ in the Muskogeanist literature) and concomitant segmental changes including lengthening, nasalization, or aspiration. Koasati also has a rich intonation system featuring at least two levels of prosodic constituents, the accentual phrase and the intonational phrase, which are associated with boundary tones and/or pitch accents that often temporally overlap with lexically specified pitch accents. Our results will be compared with those for Creek (Johnson and Martin 2001, Martin and Johnson 2002) and Chickasaw (Gordon 1999, 2003, 2004, 2005, 2007, Gordon etal. 2000, Gordon and Munro 2007), Koasati's prosodically best described relatives. [Work supported by NSF.]
Louder is longer: Amplitude conditioned lengthening in diasporic Siraiki
Authors: Arora Aditi , Dutta Indranil
Published: October 2011

Based on a longitudinal study of three generations of diasporic Siraiki speakers in India, it is shown that first generation (Gen1) implosives develop into lengthened plosives, intervocalically, in the subsequent two generations (Gen2/Gen3). Historically, Prakrit geminates developed into Siraiki and Sindhi implosives. Ohala (1992a) observes that maintaining voicing during intervocalic geminates is facilitated by increased oral cavity volume, achieved by lowered larynx (LL). The consequence of this cavity enlargement is listener misperception of the accompanying cues that lead to the genesis of implosives in the intervocalic position in Sindhi (Ohala, 1993). Closure voicing durations, root mean square (rms) amplitude during closure, and f0 following release are measured in this study. It is observed that in contexts where the Gen1 speakers produce increased rms amplitude at the release of implosives, the subsequent Gen2/Gen3 produce lengthened plosives. Increased peak-amplitude has been shown to be a weak cue for initial voiceless long consonants in Pattani Malay (Abramson, 1998). Based on the evidence from this study and Pattani, it is argued that the acoustic consequence of the feature LL, mainly increased amplitude, allows a Gen2/Gen3 mapping of the Gen1 implosives onto lengthened plosives. This mapping suggests that in addition to listener misperception, sound changes result from articulatory-acoustic mismatch.
Phonetic vowel hiatus in Spanish
Authors: Varis Erika
Published: October 2011

Phonologically, Spanish tolerates sequences of adjacent vowels at a word boundary, but coalescence and deletion have been impressionistically identified at this juncture as phonetic resolution strategies (Alba, 2006). In other languages, phonetic measurements of vowels in hiatus show gradient distinctions between different prosodic environments, supporting a gestural overlap analysis that produces the perception of deletion or coalescence (for example, Igbo, Catalan, and Greek). The current experimental study investigates phonetic manifestations of vowel hiatus in four prosodic environments (IP, PP, Pwd, and clitic) in Spanish to determine whether hiatus resolution is accomplished by vowel deletion or gestural overlap. The study was conducted with nine native speakers of Peninsular Spanish. The duration and formant frequencies of vowel sequences was measured in read sentences that manipulated boundary strength separating the two vowels. Higher-level prosodic boundaries IP and PP produced no significant hiatus effects, but vowels separated by lower-level Pwd and clitic boundaries showed formant influences of one vowel on the other. The durations of the two-vowel sequences were longer than singleton controls across all conditions, indicating no vowel deletion. The results support an analysis of vowel gesture overlap and reject deletion, contrary to auditory impressions but consistent with the findings in other languages.
Intonation of Mandarin speakers in their English as a Foreign language
Authors: Barto-Sisamout Karen
Published: October 2011

Does the prosody of speakers' first language (L1) influence their prosody in their second language (L2)? The current work investigates this for tone languages (Beijing Mandarin and Taiwanese Mandarin) as L1, and an intonation/stress language, English, as L2. English uses F0 contours in the intonation system, to signal syllabic prominence in a word, word prominence in a phrase, and the difference between questions and statements. In English, there is a pitch peak delay, where the F0 peak occurs after the stressed syllable in two-syllable stress-initial words. Conversely, tone languages use F0 contours lexically, and in the case of Mandarin, the F0 peak is on the stressed syllable. Thus, F0 measurements were taken from three subject groups (Beijing Mandarin L1, Taiwanese Mandarin L1 and Native English) who produced narrow and broad focus statements and questions, to learn if the Mandarin speakers lack pitch peak delay in English like in their L1, or delay some of their pitch peaks beyond the corresponding syllable offset, like English speakers. Further, all groups produced contrastive focus statements and questions, to see to what degree differences in the L1 system impact L2 production, as Beijing and Taiwanese Mandarin differ in these structures. Data analysis is ongoing.
Acoustic correlates of spanish speech rhythms
Authors: Harris Michael J. , Gries Stefan Th.
Published: October 2011

This paper describes a study of the acoustic correlates of speech rhythms of Hispanic Bilinguals living in California and Mexican Monolinguals living in Mexico City in order to study the effect of bilingualism on language, especially on rhythm classes, and the reliability of acoustic correlates in distinguishing these classes. This study addresses stress-timing versus syllable-timing as described in Pike's pioneering work (1945). Ten monolingual speakers from Mexico and ten bilingual Spanish–English speakers born and raised in California to Mexican parents were recorded speaking spontaneously. Fifty vowel durations per speaker were collected from phrases in these recordings and explored statistically and graphically with R.2.12.2 (R Development Core Team, 2011) in order to determine the reliability of various acoustical correlates of language rhythms in differentiating speech rhythms between varieties of Spanish. Specifically the Pairwise Variability Index, introduced by Low and Grabe (1995), and interval measures, such as the standard deviation and normalized standard deviation of vowel durations, were explored. The effects of word frequencies, as determined by relevant files from the Corpus del Espa'ol (Davies, 2002), were also considered in the analysis of the data. [Work supported by a grant for the University of California Institute for Mexico and the United States (UC Mexus).]
Effect of linguistic background on convergence of prosodic rhythm
Authors: Rao Gayatri , Smiljanic Rajka , Diehl Randy
Published: October 2011

Speech patterns of the interlocutors become more similar to each other over the course of an interaction. These spontaneous speech adaptations, or phonetic convergence (PC), have been demonstrated for segmental features, such as vowels and voice onset times (VOT) and for suprasegmental features, such as stress. In this study, speaker adaptations to speech rhythm are examined before and after an interactive map task. Using American English and Indian English speakers, convergence was measured using the centroid of the envelope modulation spectrum (EMS + centroid, Rao & Smiljanic, 2011). This spectral measure of rhythm goes beyond considering consonantal and vocalic duration variability, as used in the traditional rhythm measures, and includes information about syllable prominence, stressed and unstressed syllable variation and distribution, and pauses and disfluencies. This research will allow us to examine whether language background has an effect on convergence of global speech properties, such as linguistic rhythm. The results of this study add to our current knowledge of features that are subject to imitation in the speech of dialogue partners.
A biologically inspired neural network for modeling phrase-final lengthening
Authors: Rusaw Erin C.
Published: October 2011

This work proposes a central-pattern-generator-inspired neural network model for the interaction between phrase-final lengthening and stress. Recent work in the area of speech prosody has been concerned with the mechanisms involved in phrase-final lengthening, and specifically how phrase-final lengthening interacts with stress or prosodic prominence. The current study investigates the interaction of stress and lengthening at the end of English phrases. Adult American English speakers were recorded reading aloud sentences in which phrase boundaries had been manipulated so that the target words were either phrase-final or phrase-medial, and the durations of syllables in the target words were compared between the two conditions. Results so far support previous findings that phrase-final lengthening in English affects stressed syllables near phrase boundaries and phrase-final syllables while leaving unstressed syllables between the two unaffected [Turk and Shattuck-Hufnagel, 2007]. Domain-based models of prosodic lengthening have so far been unable to provide a unified account of this phenomenon. A biologically plausible artificial neural network is shown which provides a model of the mechanism behind this interaction using three oscillators with differing periods which input to three interconnected thresholded integrate-and-fire artificial neurons, the output of which determines the timing of the syllables, stress feet, and phrase.
Boundary enhanced scattering by solid metallic simple geometric shapes: Experiments and modeling
Authors: La Follett Jon R. , Marston Philip L.
Published: October 2011

The presence of a flat reflecting boundary can enable target scattering mechanisms that are not possible for objects in the free field. Experimental results demonstrating a strong boundary related backscattering feature for a solid aluminum cylinder near an air–water interface will be presented. This effect has been modeled previously [J. R. La Follett, Ph.D. thesis, WSU (2010)] by treating the volume of water bounded by the top surface of a solid cylinder and the air–water interface as a waveguide; qualitative agreement between the model and experimental results was demonstrated. In the present work that model is extended to incorporate aspects of the scatterer geometry. Monostatic and bistatic experimental measurements were obtained by suspending a solid aluminum cylinder, solid steel sphere, and a rectangular aluminum bar through the air–water interface of a tank. Model predictions for a solid cylinder are in good agreement with the observed dependence of the feature on the distance from the cylinder to the air–water interface. [Research supported by the NSWC PCD In-house Laboratory Independent Research program.]
Sound speed, pulse spreading, and reverberation in muddy bubbly sediments
Authors: Carey William M. , Pierce Allan D.
Published: October 2011

The sound speed characteristic of the high-porosity mud has been found to have sonic speeds lower than expected. Since the presence of bubbles is known to be an important factor in decreasing the sound speed, these low sound speeds are attributed to methane microbubbles that result from biological decay. A theoretical treatment of “muddy sediments,” the Card House Theory (Pierce and Carey, POMA (5), 7001, 2009), estimated the slow sound speed and frequency dispersion proportional to mud porosity, Cmud ∼ (0.91–0.97)Cw. The presence of microbubbles can lower the sound speed consistent with the Mallock-Wood equation [Carey and Pierce, A 1aUW6, J. Acoust. Soc. Am. 129(4,Pt2) April 2011]. The recent Dodge Pond experiment found low sound speed estimates consistent with bubble volume fractions between 10–4 to 10–5. The experiment has also produced estimates of pulse time spreading and reverberation. This paper interprets these results in terms of a three-component mixture with the bubbles distributed in a random Poisson process. Since measurement of the bubble size distribution within the mud is difficult, limits on the distribution may be obtained by the frequency dependent nature of the sound speed, pulse spreading, and reverberation characteristics. [Work sponsored by ONR OA and NSWC PCD.]
Variability of horizontal interference structure of the sound field in the presence of moving nonlinear internal waves
Authors: Badiey Mohsen , Katsnelson Boris , Malikhin Andrey
Published: October 2011

Variations of the low-frequency sound field when a train of nonlinear internal wave (NIW) crosses the acoustic track are considered. Three positions of moving NIW train, during 10:30 to 11:37 GMT on 19 August 2006 are examined. During this time, three periods of sound transmission took place, each lasting about 7.5 min. These periods referred to as starting time (10:30–10:37.5 GMT), mid-time (11:00–11:07.5 GMT), and the end-time (11:30–11:37.5 GMT). Low frequency modulated signals centered at 300 Hz, and bandwidth of 60 Hz with duration of about 2 s were transmitted. During this time, NIW consisting of 6-7 separate solitons was shifted in horizontal position by 2.5 to 2.8 km, moving toward the coast at the velocity of about 0.75 m/s. Fluctuations of the sound field in horizontal plane are described in detail for three periods of the sound pulses radiation: near the forward front, in the middle of the train, and near the back front using the fluctuations of an angle of horizontal refraction. Estimation of this angle using experimental data and those of the corresponding theory show the same value. [Work supported by ONR.]
Statistical analysis of northern Philippine Sea underwater sounds
Authors: Moskovitz Brianne , D'Spain Gerald , Worcester Peter , Dzieciuch Matt , Heaney Kevin D. , Mercer Jim , Baggeroer Art
Published: October 2011

The deep ocean experiment, PhilSea09, was conducted April–May, 2009, in the central part of the northern Philippine Sea. The deep 1000-m section of the distributed vertical line array (DVLA), which was composed of 30 elements (upper 10 at 90 m spacing starting at 4285 m depth, and 5 m spacing for the deepest 20 elements over the depths 5185–5280 m), recorded primarily four types of sounds not created as part of the experiment: wind noise, ship noise, airgun signals, and earthquake T-phases. The statistical properties of these sounds are examined quantitatively using non parametric statistical tests operating on the single element and beam level narrowband envelope time series. These statistical tests include the Wald-Wolfowitz runs test for mutual independence of the data samples, the Kolmogorov-Smirnov two-sample test for stationarity, and the Lillifors test for Gaussianity. One result is that these sounds, except for wind-dominated noise, fail the test for Gaussianity. Higher-order spectral analysis is performed to quantify the degree of non-Gaussianity. In addition, analytical probability density functions are fit to the histograms of the envelope values. Physics-based models are developed to predict the statistical characteristics of some of these sounds. [Work supported by the Office of Naval Research.]
A scaled physical model to study underwater noise from impact pile driving
Authors: Woolfe Katherine F. , Shahab Shima , Morales Juan , Hastings Mardi C.
Published: October 2011

Development of computational models to predict underwater noise from impact pile driving is limited because of the difficulty and cost involved in collecting acoustic field data for model verification during construction activities. To alleviate this situation, a scaled physical model for marine pile driving was designed and implemented in a 500-gallon shallow water tank, 3.5 m long and 0.85 m wide. The scaled piles are steel pipes having lengths up to 1 m, and radius-to-wall thickness and length-to-radius ratios similar to large cast-in-shell steel (CISS) piles. The wavelength-to-depth ratio for the primary breathing mode of the fully submerged scaled piles and a fully submerged CISS pile of diameter 2.4 m and length 30 m is between 2.0 and 2.5. The impact force is generated and measured with an impulse hammer, and sound field data are collected using a small 2-D hydrophone array. Data are correlated with the results of numerical and analytical models developed to predict sound radiation from CISS piles to verify that the scaled physical model accurately represents their structural acoustics behavior. [Work supported by the Georgia Institute of Technology and the Oregon Department of Transportation.]
Non-cavitating propeller noise source inversion
Authors: Seong Woojae , Lee Jaehyuk , Hyun Ara , Lee Junghoon
Published: October 2011

Ship's propeller cavitation generates major inboard noise and vibration over the aft body surface of a ship. During the last decade, cavitation-induced hull pressure forces have been reduced considerably leading to reduced noise and vibration levels owing to cavitation, in which case the non-cavitating components of propeller excitations have to be considered: pressure fluctuations due to blade loading and blade thickness. In this work, an algorithm to invert for the non-cavitating propeller noise source parameters based on the experimental data in a cavitation tunnel is shown. The fluctuating hull pressure is estimated by forward modeling based on acoustic boundary element method (BEM). The propeller blade loading and thickness noise sources are modeled using rings of dipoles and quadrupoles, respectively. The inversion for these pseudo sources are carried out by matching the data obtained from a cavitation tunnel experiment, where several hydrophone are flush mounted on the ship's surface near the propeller. Proper inversion results are obtained when six or more dipole and quadrupole rings are placed at each blade. Using the inverted source parameters, hull pressures were estimated, which show good agreement with the experiment data.
Anatomy of a Northeastern Pacific Ocean Sciaenid Fish, the White Weakfish (Atractoscion nobilis)
Authors: Schilt Carl R. , Cranford Ted W.
Published: October 2011

Anatomy of a Northeastern Pacific Ocean Sciaenid Fish, the White Weakfish (Atractoscion nobilis) Carl Schilt, Bigleaf Science Services, North Bonneville, WA and Ted Cranford, San Diego State University, San Diego, CA. The bony fish family Sciaenidae, commonly called the croakers, grunts, and drums, are as bioacoustically interesting as their names suggest. Although the anatomy and bioacoustics of some North Atlantic Ocean forms have been investigated, those of the Pacific Ocean are less-well studied. The white weakfish (or white seabass, Atractoscion nobilis) is a near-shore marine sciaenid of the West Coast of North America and is the target of sport and commercial fisheries and the subject of a substantial stock enhancement program. Two fresh post-mortem specimens of the white weakfish were subjected to CT scanning on two different spatial scales. The full body of the larger animal, about 1 m long total length (TL), was scanned at a 0.625 mm voxel size whereas the head of a much smaller specimen (about 20 cm TL) was scanned in a “micro-CT scanner with a voxel size of 90 μm. Images and measurements of both specimens, especially bioacoustically relevant anatomy and comparisons with other sciaenid species, will be presented.
Characterization of shape diversity in bat biosonar beampatterns
Authors: Motamedi Mohammad , Cai Lvyin , Xu Qiuping , Mio Washington , Müller Rolf
Published: October 2011

Numerical beampattern estimates for a large digital shape data set with 361 three-dimensional models of the pinna and noseleaf shapes from 106 different bat species are currently in preparation. Shape samples in this data set have been selected to represent taxonomic diversity and balance noseleaves versus pinnae. The data set will be used to analyze the biodiversity in bat beampatterns. In order to facilitate the extraction of interspecific patterns, spherical harmonics are being evaluated as an analysis tool to describe the spatial frequency content of the beampatterns. Spherical harmonics are the angular portion of a set of solutions to Laplace's equation represented in a system of spherical coordinates. The higher the harmonic, the more solutions are in the respective set. Regardless of the number of solutions, each set forms an orthogonal system. For a compressed characterization of the beampatterns, the representation of the beampattern shape at a given frequency is expressed as a power spectrum; the norm of the vector of the weighting coefficients for all basis functions in the set of a harmonic is taken to represent the portion of the total power explained by a particular harmonic. This power spectrum was found to reflect several beampattern properties well.
Reception beamforming in horseshoe bats is a dynamic process
Authors: Feng Lin , Müller Rolf
Published: October 2011

Horseshoe bats execute conspicuous pinna movements as part of their biosonar behaviors. These movements contain rigid rotations as well as deformation components that can result in considerable changes to the pinna shapes. Since pinna shape determines the biosonar system's sensitivity as a function of direction and frequency, these non-rigid deformations could be functionally relevant. In the work reported here, it has been investigated how the non-rigid deformations of pinna shape relate to the arrival of echoes. For this purpose, multi-camera high-speed video recordings of both pinna of a bat were synchronized with ultrasonic recordings of the emitted pulses and the returning echoes from a microphone placed next to the head of the animals. Landmark dots were painted on the pinna to enhance the determination of position and velocity from stereo pairs of video recordings. It was found that the pinnae were deformed between as well as during echo receptions. Hence, the echoes were received by different static each pinna shapes (e.g., bent or upright) as well as by pinna shapes that underwent non-rigid deformation within the duration of the echo. As a consequence, echo reception by horseshoe bats involves dynamic beampatterns that can change between as well as during echoes.
A semi-analytical ray method to predict the propagation of long-range vertical noise: Application of NORD 2000 to the prediction of aircraft en-route noise
Authors: Poulain Kieran , Sparrow Victor
Published: October 2011

In the past, considerable efforts were made into developing models for the prediction of short-range propagation, in the context of airport noise (Integrated Noise Model, FAA) or more generally for short-range horizontal community noise propagation (NORD 2000, Delta Inc.). Recent research efforts have focused on the prediction of aircraft en-route noise for flights above 18 000 feet above ground level (AGL) (5.49 km AGL), in order to estimate the noise impact in U.S. National Parks and other quiet areas. Unlike other community noise issues, long-range vertical propagation requires an altitude-stratified and realistic atmosphere, which directly impacts the geometrical and absorption losses as well as the ground effects. Given the large distances involved, the use of a semi-analytical propagation model based on the ray theory could prove to be useful in reducing the computation time. NORD 2000, based on semi-analytical ray theory, was modified for use with aircraft en-route noise. A comparative study against AERNOM (Advanced En Route NOise Module, based on the numerical ray method) from Penn State is presented. [Work supported by VOLPE National Transportation Systems Center. The findings are the views of the authors and do not necessarily reflect the views of VOLPE, the FAA, NASA, or Transport Canada.]
Evaluation of procedural changes for minimizing noise impact near military airfields
Authors: Christian Andrew , Sparrow Victor , Downing Micah , Bradley Kevin
Published: October 2011

Over time, communities surrounding military airfields tend to grow, while the noise generated by subsequent generations of military aircraft tends to increase. This creates an accelerating problem of human exposure to noise. One technique to alleviate this disparity is to modify attributes of flight trajectories in a way that reduces the sound exposure of the population. This involves the changing of flight ground tracks, profiles, and power settings within linear and non-linear boundaries which can include exceptions (such as no-fly-zones.) To demonstrate the effectiveness of these changes, DNL levels are calculated for real world population distributions and existing Navy departure procedures. These values are generated computationally using the widely accepted NoiseMap model. It is shown that significant reductions of exposure averaged over the population can be achieved in this way. Possible methods for automating this procedure are discussed. Properties of the objective function spaces are explored (e.g., convexity) and the appropriateness of different optimization methods is discussed. [Work supported by Naval Air Warfare Center.]
Theoretical and numerical modeling of a parallel-baffle rectangular duct
Authors: Borelli Davide , Schenone Corrado , Pittaluga Ilaria
Published: October 2011

The paper describes the theoretical and numerical analysis of sound attenuation in a parallel-baffle rectangular ducts. Insertion losses in a frequency range up to 8000 Hz were predicted by means of a FEM numerical model and by means of analytical models from Sabine and Kurze. The models were then validated in the frequency range from 125 to 8000 Hz by comparing theoretical and numerical results with experimental data obtained in accordance to EN ISO 11691 and EN ISO 7235 standards. The results of the comparison indicate that the behavior of such a dissipative/reactive silences, with its internal-reflections and energy dissipation phenomena, can be predicted quite well by the FEM model on the whole frequency range. On the contrary, analytical models show little accuracy and such predictions are not always so accurate as design requires; besides, the complexity of the analytical approach tends to limit its application to the common design practice. Overall comparisons suggest that FEM modeling can be an accurate and inexpensive way to predict sound attenuation in parallel-baffle mufflers and fulfile the ever rising needs of proper methods in acoustic design of AC and ventilation plants.
Sound quality characteristics for transient noise of high speed railway interior
Authors: Park Buhm , Lee Sinyeob , Choi Sunghoon , Park Junhong
Published: October 2011

This study presents interior noise characteristics of Korean high-speed train under different operation conditions. The interior noise was measured for various operating conditions such as different speeds, concrete and ballast track, and open and tunneled track, passing by another moving train. The transient variation of the sound pressure was recorded. The objective and subjective sound quality evaluation of the interior noise was performed. For quasi-static sounds measured for open lands and in tunnel, Zwicker's loudness has dominant impact on the annoyance. When there are transient variations in the sound pressure encountered during entrance, exit, and passing by, the sharpness and roughness also have significant impact on the perceived annoyance. The obtained data are useful for the design of interior of the train since the transient variation of the sound pressure level is influenced also by the sound environment in the room.
Measurement and analysis of squeal noise of vehicle wiper system
Authors: Min Dongki , Jeong Seongbin , Kang Heewon , Yoo Honghee , Park Junhong
Published: October 2011

The squeal noise occurring from rubber and hard surface is an important issue, especially for vehicle wiper system. The noise is generated at relatively high frequency ranges, and its generation mechanism during the wiper operation is not straight forward to understand. In this study, experimental setup to generate the squeal noise in a consistent manner is designed using a rotating glass table. The wiper is located on the glass table in compressed status so that to simulate the wiper in the actual operating system. While the glass was rotating with constant velocity, the windshield washer fluid was sprayed on the glass. Under the normal constant velocity of the wiper operation, the condition (temperature, moisture contents, velocity) of continuous occurrence of the squeal noise was identified. The friction coefficient was measured, and its impact on the squeal noise generation was identified. The influence of various parameters such as the compression ratio, temperature, types of the wiper, angle of wiper installation, kinds of washer liquids was investigated using the suggested experimental setup. This provide the required information to design the vehicle wiper system that does not induce the squeal noise during the normal operation.
A cross-linguistic investigation of word segmentation by monolingual infants learning Spanish and English
Authors: Sundara Megha , Mateu Victoria
Published: October 2011

Infants' ability to find words in fluent speech is affected by their language experience. The focus of this study was the extent to which monolingual Spanish- and monolingual English-learning 8-month-old infants' segmentation abilities are tied to their familiarity with the rhythmic properties of their native language. Spanish and English are considered to belong to different rhythm classes; the former is syllable-timed, whereas the latter is stress-timed. However, in both languages CVC.CV words are predominantly trochaic—i.e., words with stress on the initial syllable (Cutler Carter, 1984; Pons Bosch, 2010). We tested segmentation of trochaic words of the form CVC.CV in Spanish and English. Spanish word segmentation was tested using the Headturn Preference Procedure and English word segmentation using the visual fixation procedure. According to Jusczyk et al.'s rhythm hypothesis, infants should fail to segment words in a rhythmically different language. Contrary to the rhythm hypothesis, preliminary data indicate that Spanish-learning infants are successful in segmenting trochees in both Spanish and English. Thus, successful transfer of word segmentation abilities by infants seems to depend upon a match in the prosodic shape of the target word across the two languages.