bluuebunny/crossref_metadata_2025 huggingface dataset:
Stimulus and rate effects on central vowels in young adult and aged adult speakers
Authors: Natzke Phoebe , Fourakis Marios
Published: October 2011

The central vowels caret and schwa occur frequently and contribute significantly to the rhythmic (prosodic) characteristics of English (Umeda, J. Acoustic. Soc. Am., 1975). Appropriate prosody contributes to the intelligibility of speech (Klopfenstein, Int. J. Speech Lang. Path., 2009), and there is evidence that it is disturbed in the speech produced by aged adults (Benjamin, Lang. Comm., 1986). The present study explores the effects of speech rate and speech material on these central vowels in the aged population, as compared to a group of young adult speakers. In addition, it contributes to the relatively scarce published research on the acoustics of speech produced by geriatric adults (Zraick etal., J. Med. Speech Lang. Path., 2005). The study reports temporal and spectral data of the vowels caret and schwa occurring in a variety of words produced at three different speech rates. Speakers included 10 healthy young speakers and 10 healthy geriatric speakers, with five men and five women in each group. [Work supported by NIH T32 DC 005359.]
Phonetic imitation in contexts of stimulus-directed and non-stimulus-directed attention
Authors: Abel Jennifer , Babel Molly , Black Alexis
Published: October 2011

Research suggests that phonetic imitation is an automatic and subconscious process, but it is clearly a behavior that is variable across participants and conditions. This experiment explores how a participant's amount and type of attention to the speech signal moderates their amount and type of imitation. Six paired conditions varied the activities of participants (all native speakers of English) while listening to the model talker (a female speaker of North American English): blocked exposure (no instructions for listening block) vs immediate shadowing; math task vs picture-drawing task; and word-memorization task vs talker-description task. In all conditions, participants' baseline productions of the stimuli list were recorded prior to exposure to the model talker. Early analyses of whole word duration suggest participants are more likely to imitate the model when their attention is not directed toward the stimuli (i.e., no particular redirection or redirection through a picture-drawing task) than when their attention is stimulus-directed (i.e., being instructed to memorize the words or describe the talker). Further analyses of other acoustic parameters which may reveal imitative behavior are currently underway and include measures of vowel duration, vowel spectra, and f0.
Sub-phonemic correlates of gender and regional identity in California
Authors: McGuire Grant L. , Aiello Angela R. , De Leon Jackie L. , El-Gabalawy Tariq , Negrete Lauren , Vanpykeren-Gerth Kasondra
Published: October 2011

Given that the Northern and Southern California have large metropolitan areas geographically and culturally separated from each other, it is to be expected that each is developing a unique linguistic identity. Despite a handful of ethnographic studies showing otherwise (e.g., Hall-Lew 2009), the West has generally been lumped into a single dialect region (Labov etal. 2006). This paper presents data showing sub-phonemic differences between the regions that break along gender lines. Vowel productions from 14 (female = 8) Northern Californians (NCs) and 15 (female = 8) Southern Californians (SCs) were analyzed for regional differences in normalized vowel quality, voice quality (spectral tilt), pitch, and duration. No major differences in vowel quality were found. However, interactions were found between region and gender for duration and voice quality. Specifically, NC females had significantly longer word durations than NC males, with no difference between genders for SC. For voice quality, H1-H2 and H1-A3 measures both demonstrated significant differences between males and females for SC, with female voices being breathier, but with no differences for NC. Currently, a perception experiment is underway to determine if listeners can use these differences to categorize voices by region.
Dynamic differences in the production of diphthongs by French–English bilingual children
Authors: Chanethom Vincent
Published: October 2011

This study examines the cross-linguistic phonetic interactions in the production of diphthongs by French–English bilingual children. Tautosyllabic vowel-glide combinations in English and French have different phonological statuses. This combination corresponds to a single segment (i.e., a diphthong) in English, but two separate segments (i.e., vowel+glide) in French. Using a picture-naming experiment, the study aims to investigate (1) whether English diphthongs (e.g., /aI/ as in bye) and French tautosyllabic vowel-glide combinations (e.g. /aj/ as in baille ‘yawn’) have different phonetic implementations and, if so, (2) whether bilingual children maintain two separate categories. Diphthongs were recorded for six monolingual speakers of French and English, and four 6-7 year-old bilingual French-English speakers living in the US. To best capture the dynamic properties of diphthongs, the curves corresponding to F1 and F2 trajectories were submitted to statistical comparisons using the Smoothing Spline ANOVA. The cross-linguistic comparisons from the adult monolingual data indicate distinct phonetic properties for the two categories. The child bilingual data, on the other hand, show variation from one child to another as a function of amount of input. Children who attend English-only schools show greater degrees of language interference than those who attend French–English bilingual schools.
Clear speech production by nonnative English speakers
Authors: Luque Jenna Silver , Bradlow Ann R.
Published: October 2011

Clear speech is an intelligibility-enhancing mode of communication often used when speakers have trouble being understood. Previous work has established that both native and non-native listeners can receive a clear speech perception benefit, though possibly to differing degrees (Bradlow and Bent, 2002). Few studies have looked at whether nonnative talkers can induce this clear speech benefit (e.g., Smiljanic and Bradlow, 2007; Rogers etal., 2010). The current study examined English clear and conversational speech by nonnative speakers from three language backgrounds (Japanese, Portuguese, and Turkish) and two proficiency levels to determine their effect on the inducement of a clear speech benefit. Native English listeners repeated back semantically anomalous sentences. The signal to noise ratio was adjusted to the level at which they could correctly repeat 50% of the words using an adaptive test similar to the Hearing in Noise Test (Nilsson etal., 1993). The results suggest that the speaker's native language may play a role in the size of the induced clear speech benefit independently of proficiency level. Additionally, accent ratings indicated a dissociation of intelligibility and accentedness. These results are consistent with the notion that variability in intelligibility is subject to language-specific knowledge by both the talker and the listener.
Temporal characteristics of child-directed speech
Authors: Ko Eon-Suk , Soderstrom Melanie
Published: October 2011

Child-directed speech (CDS) is produced with a slower tempo compared to adult-directed speech (ADS). Yet the characterization of CDS as simply slowly spoken speech masks a number of underlying subtleties. We investigated temporal characteristics of CDS as a function of speech register based on a highly controlled set of elicited data. six sentence forms containing five monosyllabic words were read several times in declarative and question intonation with three focus conditions in CDS and ADS. After an evaluation of the data through a perceptual rating task, 2301 sentences produced by one mother and five theater students were segmented at the word-level using forced-alignment tools (Yuan and Liberman, 2008). We found strong effects of the CDS register on duration across the entire sentence. Additionally, elongation in CDS applied even to the syllables without an explicit focal accent and to function words. Our data also demonstrated a highly consistent ratio of the final syllable to the sentence duration both in CDS and ADS across all subjects. These results suggest that the slow speaking rate in CDS cannot be attributed to any single effect such as the exaggerated utterance-final lengthening (Church etal., 2005) or effects of lexical categories (Swanson etal., 1992).
The development of neutral tone in Mandarin-speaking children
Authors: Yang Jie , Davis Barbara
Published: October 2011

Besides the four citation tones in Mandarin stressed syllables, neutral tone usually occurs in unstressed syllables. The fundamental frequency (F0) contour and height of neutral tone are determined by the preceding tones. Neutral tone was also considered to have lower intensity and shorter duration compared to citation tones (Cao, 1986; Chao, 1968). Li and Thompson (1977) suggested that neutral tone was not fully acquired by Mandarin-speaking children of age 2. However, the acoustic characteristics of neutral tone in the extended period of acquisition were not explored. The present study compared acoustic realizations of neutral tone in children's production with adults. Eight 5-yr-old and eight 8-yr-old mono-lingual Mandarin-speaking children and young adults participated. Bi-syllabic target words containing neutral tone in the second syllable was elicited by picture-naming tasks. F0, duration and intensity of neutral tone syllables were measured. The ratio of these acoustic parameters between the first and second syllable was calculated. Results indicated that 5-yr-old children started to produce F0 contour and height of neutral tone according to the preceding tone.
Executive abilities for spoken-word commands: Inhibiting conflicting responses in voice-tone classification by adolescents and adults
Authors: Espinoza-Varas Blas , Jang Hyunsook , Lack Caleb , Luna Beatriz
Published: October 2011

The inhibition of responses prompted by conflicting laterality cues and response-mapping rules was studied while participants classified the voice-tone of word commands. Announced by the cue words /left/ or /right/, target word commands for impeding or instigating actions (e.g., /quit/ or /go/), spoken in stern or lenient tone, stimulated the left or right ear. Each trial presented a cue followed by a target (e.g., left-quit), and participants classified the target voice tone as lenient or stern with a left or right (or the reverse) response for impeding (or instigating) commands. Within a trial block, laterality-conflict conditions presented impeding or instigating words only and, on each trial, the cue and ear side were congruent or in conflict with the correct response side. Response-mapping conflict conditions presented impeding and instigating words within each trial block, and correct classification required adhering to the respective mapping. Without conflict, error percent was larger with instigating than impeding commands, and in adolescents than adults. With instigating commands, laterality conflict increased the errors in both groups but only in adolescents with impeding commands. Errors increased further with laterality and mapping conflict, especially in adolescents. The adolescent response inhibition is inferior to the adult. [Funded by ABMRF.]
Propagation of coupled modes in three dimensions
Authors: Pannatoni Ronald F.
Published: October 2011

A time-harmonic acoustic field in an ocean can be represented in terms of local normal modes. This representation may include leaky modes to account for radiation into the bottom. A system of coupled elliptic equations governs the amplitudes of these modes. If there is a primary horizontal direction of propagation, it may be possible to approximate these equations by parabolic equations. The resulting system of coupled parabolic equations can be integrated in the direction of propagation only if a certain linear transformation is nonsingular. This constraint limits the size of the system and the amount of coupling among the modes that are consistent with the parabolic approximations. A method for integrating the coupled parabolic equations numerically is discussed, and it is applied to a problem of three-dimensional propagation and scattering around a conical seamount in a deep ocean.
Mapping the landscape of soundscape research
Authors: Kobayashi Hill , Saito Saoru
Published: October 2011

In this paper, I give a personal view on what could be the landscape of soundscape research. I will describe the philosophical content of this discipline, the current state of aesthetic aspect, the challenges in technical issues and the future direction of Soundscape activities among researchers, practitioners, designer, and composers. Given that to map a landscape of this discipline with discussion is a very challenging task. It requires us to connect knowledge from different disciplines with perceptional sense. The paper aims to address recent collaboration opportunities for interdisciplinary engagement and key topics for debate.
Sounds in cause: Soundscape and evolution
Authors: Berenguer José Manuel
Published: October 2011

Beyond the therm of landscape, that has often been defined as “a painting, drawing, or photograph depicting natural scenery,” the concept of soundscape should lack any aesthetic significance and be thought as a technical therm naming the whole sonic experience of animals having sense of hearing. In general, from a methodological point of view, approaches describing landscape as “a view of some natural place” does not seem to be useful, because artificial and natural are often indistinguishable. Soundscape does not need to be considered natural or artificial. For instance, it seems evident that in a city, most sources of sound objects in soundscapes are human activities; anyway, even in a city, sounds produced by non-human species can easily be found. Soundscapes are complex structures that can be considered in terms of evolution. They evolve sound sources adapt their sonic productions to sonic productions of other sound sources sharing the same environment. It happens in human and non-human soundscapes. This way of thinking underlies sounds in cause, a project that started building a database of soundscapes recorded following a strict methodology and now proposes an Internet2 Network of Laboratories and Stations for Permanent Listening to the Soundscape.
Using a soundscape approach to develop an acoustic ecology plan for a city
Authors: Lavia Lisa R. , Dixon Max , Axelsson Osten , Witchel Harry
Published: October 2011

Sounding Brighton is a collaborative project exploring practical approaches toward better soundscapes focusing on soundscape issues related to health, quality of life, and restorative functions of the environment. The project provides the opportunity to raise awareness and promote communication on soundscapes among the general public, stakeholders and those involved in policy, including encouraging exploration of new ways of listening in local soundscapes, and new ways of tackling noise and improving local soundscape quality. The project is working to provide opportunities to discuss how soundscape concepts might, alongside tackling conventional noise problems, contribute to local planning and environmental improvement as part of a city wide engagement process in the city of Brighton and Hove in England in the United Kingdom. A range of environments, e.g., seafront, foreshore, historic terraces, squares, lanes, parks, and gardens, are being considered. A soundmap of the city is being developed utilizing the Swedish Soundscape-Quality Protocol (developed by Osten Axelsson, Mats E Nilsson and Birgitta Berglund); a public outreach exhibition is being developed; and a night noise intervention study is planned to explore the relationship between soundscapes and the brain, community well being, social cohesion, and the physical and mental health of individuals.
Successfully merging architectural and electronic acoustical treatments
Authors: Barbar Steve
Published: October 2011

In enclosed volumes, the integration of electronic acoustical components with architectural surface treatments forms a hybrid system that produces the perceived acoustical conditions. Since the underlying operating principles for electro-acoustic enhancement systems differs considerably between manufacturers, the requirements for system infrastructure are not germane, nor is the optimum integration of architectural treatments. As a result, the nature of the work performed by the acoustical consultant changes to accommodate optimum performance of the specific “hybrid” system, which may also include other forms of variable treatments.
Various applications of active field control
Authors: Watanabe Takayuki , Ikeda Masahiro
Published: October 2011

Several types of various active field control (AFC) applications are discussed, while referring to representative projects for each application. (1) Realization of acoustics in a huge hall to classical music program, E.g., Tokyo International Forum: This venue is a multi-purpose hall with approximately 5000 seats. AFC achieves “loudness” and “reverberance” equivalent to those of a hall with 2500 seats or fewer. (2) Compensation of acoustics on stage without rigid shell using the electro-acoustic method. E.g., High school auditoriums: In these renovation projects, AFC achieves “acoustical support” for performer on stage and “uniformity” throughout the auditorium from the stage to the audience area, etc. (3) Improvement of the acoustics under the balcony in auditoria. E.g., Experiments on a full-scale model and the school auditorium. The system is a non-regenerative system, and the loudspeakers, located at positions corresponding to measurement points across the balcony, recreate the reflecting sound from above the balcony area, which otherwise fail to reach to the listeners under the balcony. The results of the experiment show that the system is significantly better for all tests to the use of no system and that the system is superior to a standard PA (delay system).
Acoustic repair: Recent experience with the acoustic control system (ACS) for improving acoustic conditions in two existing venues
Authors: Gulsrud Timothy E. , van Maurik Arthur
Published: October 2011

Active acoustics systems are becoming more prevalent in architectural acoustics practice, particularly in the context of repairing or improving acoustics in existing venues. Governmental policies to reduce funds and subsidies put into new facilities for the performing arts are another reason for designers to consider the use of active acoustics. This paper highlights two recent examples of such installations of ACS systems, one at the Sydney Opera House Concert Hall, and the other at MBCCH, Winnepeg, Canada. Collaboration between the system designer, the musicians, and the acoustics consultant will be emphasized, along with techniques used to evaluate the systems' performance in the halls.
Acoustical design of Soka University Performing Arts Center
Authors: Kallas Kayo , Komoda Motoo , Toyota Yasuhisa
Published: October 2011

The Soka University Performing Arts Center and Academic Building will open in September 2011. The $73 million performing arts center is open to the public, hosting various types of performing arts. For lovers of the performing arts, the center will become another choice among the many fine venues in Orange County. The building houses a 1000-seat multipurpose hall, a 150-seat black box theater, support spaces, and classrooms. The multipurpose hall was designed primarily as a concert hall, and later to become suitable for dance, plays and musicals. To satisfy these flexible programs, the design features a curtain system for variable acoustics and an automated stage lift to accommodate concert, thrust, and convocations stage settings. The seating layout of the multipurpose hall was arranged in the arena style. The room shape and interior materials were carefully selected to optimize the acoustics of the space, including the two layered ceiling design: one for aesthetics and the other for room acoustics. Acoustical design and characteristics of the new multipurpose hall will be reported.
Passive acoustic monitoring of sperm whales during and after the Deepwater Horizon oil spill
Authors: Merkens Karlina , McDonald Mark A. , Baumann-Pickering Simone , Frasier Kaitlin , Wiggins Sean M. , Hildebrand John A.
Published: October 2011

The Deepwater Horizon oil spill during the summer of 2010 impacted a region of sperm whale habitat along the continental slope and deep waters of the Gulf of Mexico. Passive acoustic monitoring was used to study the potential impact of the oil spill on sperm whales by recording trends in their characteristic sounds, such as echolocation clicks and foraging creaks. High-frequency Acoustic Recording Packages (HARPs) were deployed shortly after the oil spill began; one was located close to the Deepwater Horizon well, above which the sea surface was contaminated by oil throughout the summer of 2010, and another was deployed in a region of sperm whale habitat that remained unexposed to surface oil to function as a “control” site. At both sites, sperm whales were detected on a majority of days during the nearly year-long recording period. Sperm whale presence was evaluated from detected clicks and creaks, and changes in these sounds over time and between sites were compared.
Effects of physical properties of the skull on high intensity focused ultrasound for transcranial sonothrombolysis
Authors: Selvaraj Prashanth , Okita Kohei , Matsumoto Yoichiro , Voie Arne , Hoelscher Thilo , Weiss Hope , J. Szeri Andrew
Published: October 2011

The use of high intensity focused ultrasound (HIFU) in transcranial sonothrombolysis is emerging as a promising therapeutic intervention after stroke. Of interest in the present study is the evolution of the wave from transducer to focus, with special attention to two aspects. One is the attenuation of the wave before it reaches the focus, the other is the scattering of the wave at tissue interfaces leading to alteration of the focus. A code developed for tissue ablation (Kohei Okita, Kenji Ono, Shu Takagi, and Yoichiro Matsumoto, Int. J. Numer. Methods Fluids 65:43–66 (2011)), has been modified to study the effect of the physical properties of the skull on the focusing of the HIFU waves. Phase delay of the array transducer is employed to focus the waves. A basic model illustrative of the calvaria of the skull has been used as only the physical properties of the bone are of interest here. Microbubble cavitation has been shown to enhance sonothrombolysis; hence, the altered wave is examined from the point of view of the bubble dynamics it engenders.
Acoustic particle velocity amplification with horns
Authors: Donskoy Dimitri M.
Published: October 2011

Previously [Donskoy and Cray, J. Acoust. Soc. Am., 129(4), Pt. 2, 2644 (2011)] the authors numerically investigated an acoustic particle velocity amplification effect with conical open-ended horns. Here, using Webster's approach, an analytical solution for the particle velocity response of conical horns (single and double) is derived and analyzed. The solutions are verified by comparison with direct numerical computations and supported with experimental measurements. It is shown that small horns, compared to the acoustic wavelength, are capable of providing substantial particle velocity amplification. For example, a 20 cm horn, in-water, can deliver nearly 10 dB of amplification over a very broad frequency range (from zero to 1000 Hz) without significant amplitude and phase distortion. Another unique feature of the velocity horn is its dipole directionality. The paper presents a thorough analysis of horn's amplification versus geometrical parameters. [This work is supported in part by the ONR summer fellowship program].
Ares I scale model acoustic test lift-off acoustics
Authors: Counter Douglas D. , Houston Janice
Published: October 2011

The lift-off acoustic (LOA) environment is an important design factor for any launch vehicle. For the Ares I vehicle, the LOA environments were derived by scaling flight data from other launch vehicles. The Ares I LOA predicted environments are compared to the Ares I scale model acoustic test (ASMAT) preliminary results.
Ares I Scale Model Acoustic Test above deck water sound suppression results
Authors: Counter Douglas D. , Houston Janice
Published: October 2011

The Ares I Scale Model Acoustic Test (ASMAT) program test matrix was designed to determine the acoustic reduction for the LOA environment with an above deck water sound suppression system. The scale model test can be used to quantify the effectiveness of the water suppression system as well as to optimize the systems necessary for LOA noise reduction. Several water flow rates were tested to determine which rate provides the greatest acoustic reductions. Preliminary results are presented.
Hybrid computational fluid dynamics and computational aero-acoustic modeling for liftoff acoustic predictions
Authors: Strutzenberg Louise L. , Liever Peter A.
Published: October 2011

This paper presents development efforts at the NASA Marshall Space flight Center to establish a hybrid computational fluid dynamics and computational aero-acoustics (CFD/CAA) simulation system for launch vehicle liftoff acoustics environment analysis. Acoustic prediction engineering tools based on empirical jet acoustic strength and directivity models or scaled historical measurements are of limited value in efforts to proactively design and optimize launch vehicles and launch facility configurations for liftoff acoustics. CFD based modeling approaches are now able to capture the important details of vehicle specific plume flow environment, identify the noise generation sources, and allow assessment of the influence of launch pad geometric details and sound mitigation measures such as water injection. However, CFD methodologies are numerically too dissipative to accurately capture the propagation of the acoustic waves in the large CFD models. The hybrid CFD/CAA approach combines the high-fidelity CFD analysis capable of identifying the acoustic sources with a fast and efficient boundary element method (BEM) that accurately propagates the acoustic field from the source locations. The BEM approach was chosen for its ability to properly account for reflections and scattering of acoustic waves from launch pad structures. The paper will present an overview of the technology components of the CFD/CAA framework and discuss plans for demonstration and validation against test data.
Measurement and propagation of supersonic aeroacoustic noise sources using continuous scanning measurement technologies and the fast multipole boundary element method
Authors: Yang Michael Y. , Vold Havard , Shah Parthiv N.
Published: October 2011

ATA Engineering has developed a technique which uses a continuous scanning robot to take high-resolution measurements of supersonic jet plumes. The jet noise was modeled using a reduced-order model and propagated to far field microphone locations in the free-field. It is shown that the pressure at these microphones was successfully reconstructed across a range of frequencies. The capability to make predictions when scattering surfaces are present is also demonstrated using the fast multipole boundary element method in VA One. This work was originally designed for supersonic jets but can also be used for static firing tests of launch vehicle engines. The measured data could then be used for analytic predictions of the liftoff environment.
The shopping sound experience
Authors: Jung Ralf , Kahl Gerrit , Spassova Lbomira
Published: October 2011

The attempt to influence the shopping behavior of customers in a supermarket through music often fails due to the different music preferences. In this work, a method to bring personalized music in the supermarket is presented by providing a location-aware playback and notification service. By using a web interface, customers are able to create an electronic shopping list, associate list items with music tracks, and thus create an individual shopping playlist. These product-associated music tracks start playing at the customer's instrumented shopping cart when he enters specific product departments where an item from the shopping list is located. Additionally, a service to provide product-awareness through non-speech audio cues is presented. This location-aware service notifies customers when they come closer to products that are listed on their shopping list. A two-stage notification approach is used to create user-centric notification zones. Depending on the customer's distance to the product, he gets notified by an ambient or arousal noise that is mixed into the background music. In addition, further information about the detected product is displayed on the screen that is mounted at our instrumented shopping cart.
Statistical analysis of constriction task and articulatory posture variables during speech and pausing intervals using real-time magnetic resonance imaging
Authors: Ramanarayanan Vikram , Goldstein Louis , Byrd Dani , Narayanan Shrikanth
Published: October 2011

We have shown previously using real-time magnetic resonance imaging data (Ramanarayanan etal., 2011, ISSP Montreal) that it is more likely that articulatory posture variables (such as jaw angle) are controlled to achieve articulatory settings during pausing intervals in read speech than constriction task variables (such as lip aperture, tongue tip constriction degree, etc.). In this study, we extend this work to examine correlations between constriction task variables and articulatory posture variables during both speech and pause intervals. This work serves to deepen our understanding of the differences in postural motor control of the vocal tract observed during speaking and pausing. [Work supported by NIH.]
An ultrasound study of Canadian French rhotic vowels
Authors: Mielke Jeff
Published: October 2011

Some speakers of Canadian French produce the vowels /o// and /œ/ with a rhotic perceptual quality, leading pneu, docteur, and brun to sound like /pnr/, /dOktarR/, and /bRr/. English /r/ can be produced with a variety of tongue shapes (including bunched and retroflex variants; Delattre and Freeman 1968, etc.), raising the question of whether French rhotic vowels are also produced with categorically different tongue shapes. Mid-sagittal ultrasound video was recorded for three native speakers of Canadian French producing words containing /œ/, /œR/, and /o// in a carrier phrase. Acoustic analysis of rhotic- and non-rhotic-sounding vowels reveals that the rhotic perceptual quality is associated with a low third formant, which is an important acoustic cue for English /r/. Two of the subjects produced rhotic vowels with a tip-down bunched tongue shape closely resembling Delattre and Freeman's type 4 and one subject produced them with a retroflex tongue shape. The study provides articulatory data on retroflex vowels, which are typologically rare, and on bunched-retroflex variation in a language other than English. The parallel cases of articulatory variability in French and English raise opportunities for investigating articulatory-acoustic mapping in bilinguals.
A two-dimensional/three-dimensional hybrid structural model of the vocal folds
Authors: Cook Douglas , George Pradeep , Julias Margaret
Published: October 2011

The spatial dimensionality of the vocal fold vibration is a common challenge in creating parsimonious models of vocal fold vibration. The ideal model is one that provides acceptable accurate with the lowest possible computational expense. Inclusion of full three-dimensional (3D) flow and structural vibration typically requires massive amounts of computation, whereas reduction of either the flow or the structure to two dimensions eliminates certain aspects of physical reality, thus making the resulting models less accurate. Previous two-dimensional (2D) models of the vocal fold structure have utilized a plane strain formulation, which is shown to be an erroneous modeling approach since it ignores influential stress components. We herein present a 2D/3D hybrid vocal fold model that preserves three-dimensional effects of length and longitudinal shear stresses, while taking advantage of a two-dimensional computational domain. The resulting model exhibits static and dynamic responses comparable to a 3D model and retains the computational advantage of a two-dimensional model.
Emotion effects on speech articulation: Local or global?
Authors: Lee Sungbok , Kim Jangwon , Byrd Dany
Published: October 2011

Although differences in overall articulatory behaviors in emotional speech production have been well acknowledged in the literature, it is not well known whether such articulatory differences are distributed or localized along the time axis. In this study, we examine the lower lip and tongue tip trajectories of a perceptually evaluated EMA (electromagnetic articulography) emotional speech database of one male and two female subjects. The speech material is a set of sentences repeated at least three times, and the emotion types investigated are neutral, angry, and happy. Timing differences between repetitions as well as across emotions are normalized by the FDA (functional data analysis, Ramsay and Silverman, 1997) time- alignment technique so that important kinematic land-marks (e.g., velocity maxima) are aligned with respect to each other. Therefore, not only differences in timing but also differences in movement range and velocity can be investigated along the time line. The normalized quantities are sampled along the time line every 10 ms, with a 20-ms window, and their differences along the time line are compared as a function of emotion. Final results as well as their relation to pitch patterns and other acoustic measures will be reported. [Work supported by NIH and NSF.]
Effects of morpheme boundaries in /n/ palatalization in Korean
Authors: Sung Jae-Hyun
Published: October 2011

Korean palatalization is known to be one of the rare palatalization phenomena where the morpheme boundary plays a role. For example, /mat+i/ ‘the elderly’, where a morpheme boundary exists between /t/ and /i/, becomes [madi] by the palatalization process, while a tautomorphemic word /mati/ ‘joint’ is realized as [madi] (*[madi]), with no palatalization. The present study investigates whether the effect of morpheme boundaries is also at play in allophonic /n/ palatalization in Korean as well as in /t/ palatalization using ultrasonic analysis, and shows that morpheme boundaries contribute to allophonic variation. This study uses ultrasound imaging and audio recordings of 6 native speakers of Korean to examine the difference in palatalization between two morphologically different words in Korean—tautomorphemic words (e.g., [koni] ‘swan’) and heteromorphemic words (e.g., [muni] (/mun+i/) ‘door + nominative marker’). Comparison of the degree of palatalization before [i] shows there is stronger /n/ palatalization in tautomorphemic /n/ + [i] words than that in heteromorphemic /n/ + [i] words, in contrast to /t/ palatalization. The results from this study are in line with the reported language-universal tendency for greater palatalization in tautomorphemic environments.
Acoustic cues to prominence in children's speech
Authors: Shport Irina A. , Redford Melissa A.
Published: October 2011

Previous work indicates that phrasal prominence patterns are not yet adult-like in 6-year-old children's speech. Perception of prominence in English is influenced by temporal patterning, amplitude changes, and fundamental frequency variations across the phrase. This study examined the relative weightings of these cues to prominence in adult judgments of 6-year-old children and college-aged adults' speech. Eleven adult judges listened to two—word phrases produced by 25 children and 25 adults in a counting task designed to induce stress shift (thirtéen banana versus thirtéen barbeque). The judges decided which word was most prominent in the phrase: number, noun, or equal prominence. Although the number word was always judged to be prominent regardless of speakers' ages or context, initial results indicate that agreement between judges varied systematically with different cues in children and adults' speech. More judges agreed that the number word was prominent in children's speech when the first syllable of this word was produced with an especially high F0 and long duration, but only the relative intensity of the initial syllable predicted inter-judge agreement for adult speech. The results have implications for understanding the development of cue integration in the prominence production. [Work supported by NIH/R01HD061458.]
Prosodic pattern detection based on fuzzy set theory
Authors: Bacuez Nicholas
Published: October 2011

This research utilizes fuzzy logic and fuzzy set theory to experimentally abstract the mental representations of prosodic contours otherwise not accessible to speakers or researchers. I have developed a pattern recognition system to extract approximations of these representations and their range of variation from speech datasets. Following the principles of fuzzy set theory, a prosodic contour is defined as a category and the variation range of its components is expressed in terms of degree of membership to the category, from 0 (excluded) to 1 (included). Subsequently, the system analyzes the prosodic contour of new sentences by assessing through fuzzy matching their degree of membership to previously identified categories: 1 is perfect, 0.5 is borderline, and 0.1 is improbable. In the current study, I have used closed questions obtained experimentally from native French speakers. The prosodic contour of closed questions is non problematic and ensures the controllability of the output. The model output is an array storing the ideal curve and its degrees of variation. Fuzzy matching reveals that most closed questions from the dataset are in medium range (0.5). This materializes the idea that vagueness (Russell, Wittgenstein), the linguistic correlate to fuzzy logic, is a natural property of language.
On Rayleigh and Mie scattering
Authors: Caruthers Jerald W.
Published: October 2011

Scattering described today as “Rayleigh scattering" represents something that is far short of what Rayleigh actually contributed to the topic in both optics and acoustics. This limited view seems to lie in a few papers in which he truncates series solutions for practical computations, thus leading to scattering of the form (ka)4 for ka≪ 1, where k is the wavenumber and a is the radius of the sphere and for selected limitations on index of refraction. These approximations led optical scientists to equating “Rayleigh scattering" to little more than “the blue sky.” In 1908, Gustav Mie developed a theory for plane-wave scattering from a sphere to which the names “Mie theory” and “Mie scattering” have been indelibly attached to many applications in optics. It is virtually unknown, especially in optics, that Rayleigh actually developed the full theory of plane-wave scattering from a sphere in 1878 (primarily Section 334, Vol. 2, The Theory of Sound, Macmillan), including original contributions in the concurrently developing mathematics of Bessel functions. The motivation of this presentation is to establish a means of treating weak scattering from bubbles based on their contribution as a distribution of spheres by combining Rayleigh and Mie.
Spectral effects of nonlinear internal waves on narrowband shallow-water signal propagation
Authors: Smith Chad M. , Bradley David L.
Published: October 2011

Water column, bathymetry, and acoustical sediment properties collected during the transverse acoustic variability eXperiment (TAVEX) of 2008 are used to create a 30 km computational environment for propagation models. These models are used to display internal-wave-induced acoustic variability which is characteristic of the shallow-water northern East China Sea environment where the experimental work took place. Analyses of computational models are then compared to narrowband acoustic recordings made during the experiment using a spectral and time-of-arrival analysis approach. The expected acoustic effects and computational impact of specific internal wave characteristics on acoustic arrivals will be discussed along with recorded data comparison. [Work supported by the Office of Naval Research.]
Refraction of horizontal rays and vertical modes from receding solitary internal wave front in shallow water
Authors: Badiey Mohsen , Grogorev Valery , Katsnelson Boris
Published: October 2011

Previously, it was shown that on the approach of an internal wave to an acoustic source-receiver track in shallow water, interference between a direct and a horizontally refracted acoustic path can occur (J. Acoust. Soc. Am. 129(4), EL141, 2011). This phenomenon that is dependent on the angular geometry between the solitary internal wave (IW) front and the acoustic track is similar to the well known Lloyd mirror interference phenomenon in optics. In particular, for a specific time during the SW06 experiment, it was shown that the refracted pulse propagating along horizontal ray, corresponding to the fourth vertical mode arrives with temporal delay relative to the direct horizontal ray. In this paper, we show this phenomenon occurring on the back front of the solitary IW. On the receding front, the forth mode of the refracted signal occurs with an increasing delay in the modal arrival time as the IW leaves the acoustic track. This separation between the direct and the refracted path continues while it gets larger until the IW is far enough from the track for refraction not to occur. A theoretical description of this phenomenon in support of the experimental observation is also presented. [Work supported by ONR.]
A model for noise radiated by submerged piles and towers in littoral environments
Authors: Hay Todd A. , Ilinskii Yurii A. , Zabolotskaya Evgenia A. , Wilson Preston S. , Hamilton Mark F.
Published: October 2011

Pile driving in shallow water during the construction of bridges and other structures can produce transient broadband noise of sufficient intensity to kill fish and disturb marine mammals. Sustained tonal noise radiated by towers supporting offshore wind turbines contains energy in frequency bands that may inhibit detection of coastal activities via passive sonar and seismic sensors. Understanding the generation and propagation of underwater noise due to pile driving and wind farms is important for determining the best strategies for mitigating the environmental impact of these noise sources. An analytic model, based on a Green's function approach, is presented for the sound radiated in the water column by a submerged cylindrical structure embedded in horizontally stratified layers of sediment. The sediment layers are modeled as viscoelastic media and the Green's function is derived via angular spectrum decomposition. Noise radiation due to both vibration of the structure and impulses delivered to the sediment is considered. Contributions to the pressure field in the water column due to radiation directly into the water, radiation from the sediment into the water, and Scholte waves propagating along the sediment-water interface will be discussed. [Work supported by the ARL:UT IR&D program.]
Performance of an echolocating bottlenose dolphin in the presence of anthropogenic masking noise
Authors: Wezensky Eryn M. , Finneran James J. , Mulsow Jason , Martin Cameron R. , Branstetter Brian K. , Moore Patrick W. , Houser Dorian S.
Published: October 2011

To study the effects of acoustic masking from anthropogenic noise, bottlenose dolphin (Tursiops truncatus) echolocation performance was assessed in the presence of different masking noise types using Navy relevant source transmissions. Echolocation clicks produced by the dolphin were detected with a hydrophone, then digitized within a phantom echo generator (PEG). The PEG converted the received clicks into echoes, delayed appropriately for the simulated target range. The echoes were then broadcast to the dolphin via a sound projector while masking noise transmissions were held constant. Using an acoustic response and a modified method of constants procedure, the echolocation performance of the dolphin was computed as a function of range between 3 and 17 m. Comparative echolocation performance to different masking noise type categories was analyzed between intermittent and continuous noise, direct path transmissions and multipath exposure, and mid frequency versus high frequency bands. These results expand the limited understanding of biosonar processing capability and signal characteristic alterations used to discriminate and resolve changes in small scale features while exposed to potential noise interference types. [Work supported through the Office of Naval Research.]
Subject-based calibration of a jawphone transducer with a bottlenose dolphin (Tursiops truncatus)
Authors: Mulsow Jason , Brewer Arial M. , Finneran James J.
Published: October 2011

Hearing studies with odontocete cetaceans often use suction-cup transducers known as``jawphones” to imitate underwater stimulus transmission. Jawphones are typically calibrated by measuring a frequency-response curve with a receiving hydrophone placed at a controlled distance in an underwater direct field. This procedure is somewhat controversial, as it may not sufficiently reproduce the odontocete sound reception pathway. This study calibrated a jawphone by comparing two behavioral audiograms for a single bottlenose dolphin. The first audiogram comprised underwater hearing thresholds (in dB re 1 μPa) measured using direct-field stimulation, the second comprised thresholds (in dBV) measured using a jawphone. All thresholds were measured using a psychophysical staircase procedure at frequencies from 14.1 to 150 kHz. The calibration curve was calculated by subtracting, at matched frequencies, jawphone thresholds from underwater direct-field thresholds. The resulting curve had the shape of a bandpass filter, with highest levels at frequencies from 56.6 to 130 kHz. This subject-based curve was similar in shape to a previously obtained direct-field calibration curve, although the subject-based values were higher above 20 kHz. These results are especially relevant to auditory evoked potential hearing studies that measure thresholds in odontocetes that are untrained for psychophysical procedures. [Work supported by ONR.]
Non-rigid pinna deformations in bats—Behavioral adaptation or dynamic sensing?
Authors: Müller Rolf , Gao Li , Feng Lin
Published: October 2011

Mammal groups with exceptional spatial hearing abilities, bats and primates in particular, are known to have intricate pinna shapes. These shapes determine the monaural spatial hearing sensitivity as a function of direction and frequency, i.e., the reception beampattern. Since even comparatively small, local pinna features can have profound effects on the beampattern, it is possible that some of the interspecific diversity in these pinnae represents spatial hearing adaptations on an evolutionary time scale. In addition, some bat groups, such as horseshoe bats, have elaborate muscular actuation mechanisms that can produce non-rigid pinna deformations. These mechanisms could enable beampattern control on a much shorter, behavioral time scale. This could add considerably to the capabilities of the biosonar systems in these species, because by switching between different pinna shapes—and hence reception beampatterns—could meet even conflicting demands of different biosonar tasks. However, since pinna deformations in horseshoe bats can happen on comparatively short time scales (i.e., one tenth of a second), it is also conceivable that the bats' pinnae are in motion during the reception of an echo. It is not clear at present if and how such a dynamic receiver paradigm could be utilized to enhance biosonar performance.