bluuebunny/crossref_metadata_2025 huggingface dataset:
Extended optical theorem in elastic solids: Applications to Bessel beam scattering
Authors: Lopes J. H. , Leao J. P. , Baggio A. L. , Silva Glauber T.
Published: November 2016

We derive the extended version of the optical theorem for the scattering of an elastic wave with arbitrary wavefront by an inclusion of any shape embedded in a solid medium. The inclusion can be made of an elastic, viscoelastic, fluid, and rigid material or be an empty cavity. The extended optical theorem relates the extinction cross-section, which is defined as the time-averaged power extracted from the incident wave per incident intensity, in terms of the coefficients of the partial-wave series representation for the incident and scattered waves. With this formalism, the optical theorem for a longitudinal Bessel beam scattering is obtained in a solid for the first time. Additionally, we established the connection between the optical theorem and radiation pressure exerted on a spherical inclusion by a longitudinal and shear plane wave. In conclusion, the developed framework might be useful for beamforming in ultrasound nondestructive test and ultrasound imaging of biological tissue.
Within- and between-frequency gap duration discrimination as a function of the standard duration
Authors: Cho Hyunsoo , Ito Kazuhito , Hirose Nobuyuki , Mori Shuji
Published: November 2016

It is well known that individuals exhibit worse performance during between-frequency gap detection than during within-frequency gap detection. A similar performance difference is also found between within- and between-frequency gap duration discrimination involving undetectably short standard durations. This is reasonable because such discrimination could be considered to be a variant of gap detection. However, because of the paucity of existing data, it is unclear whether frequency differences affects gap discrimination tasks involving longer standard durations. In this study, we measured within- and between-frequency discrimination thresholds in the presence of various standard durations from 1 to 100 ms. As a result, it was shown that the within-frequency thresholds were significantly lower than the between-frequency thresholds when a standard duration of 1-ms was employed, whereas there were no significant differences between them when the standard duration was >50 ms. This implies that the within- and between-frequency gap discrimination processes become equivalent as the standard duration increases.
Comparison of 226 Hz and 1000 Hz tympanometry results in infants
Authors: Oster Monika-Maria , Werner Lynne A.
Published: November 2016

Tympanometry with a 226 Hz probe tone is a reliable indicator of middle ear disease in adults and older children. However, it is reported to produce a high rate of false-negatives in young infants. Tympanometry with a 1000 Hz probe tone has been reported to better indicate middle ear dysfunction in infants. However, age-graded norms for 1000 Hz tympanometry are currently not available. Furthermore, the results of 226 Hz and 1000 Hz tympanometry have not been compared in large numbers of infants of different ages. Tympanograms with 226 and 1000 Hz probes were analyzed from 1879 7- to 40-week-old infants to determine whether tympanometric compliance changes with age during infancy, whether 226 Hz compliance predicts 1000 Hz compliance and whether tympanometric screening results obtained with these probe frequencies agree. Preliminary results indicate that infants with 226 Hz compliance of 0.1 mmh had low 1000 Hz compliance. For infants with mean (0.3 mmh) or high (0.5 mmh) 226 Hz compliance, 1000 Hz compliance increased with age. Controlling for age, 226 Hz compliance predicted 1000 Hz compliance. For infants younger than 24 weeks, screening results nearly always agreed. For infants older than 24 weeks, 29.3% of infants passed screening at 226 Hz but failed at 1000 Hz, while almost all who passed, passed at both frequencies.
Bandwidth discrimination in normal-hearing listeners
Authors: He Yuan , Lentz Jennifer
Published: November 2016

People’s ability to discriminate between different noise bandwidths has not been fully studied. Only a few terms such as “less fluctuating” or “less noisy” are used to describe perceptual changes caused by bandwidth differences. This current study was designed to examine the discrimination threshold of bandwidth in band-pass white noises in normal-hearing listeners. In three experiments, we explored whether center frequency region and base bandwidth would affect discrimination performances, whether discriminating a broader bandwidth is easier than a narrower one, and whether bandwidth discrimination relies on additional cues provided by fixed center frequencies. Thresholds were estimated in a three-interval-three-alternative forced choice task using a three-down one-up adaptive procedure and an oddball paradigm. Visual feedback was given to aid learning about oddball stimulus. We varied the intensity level for sounds within and across trials to avoid the use of intensity cues in all experiments. We also varied the center frequency from interval to interval in one of the experiments to investigate the center frequency cues. In general, we found that normal-hearing listeners may not be very good at discriminating noise bandwidths, especially without the assistance of fixed center frequencies. Large individual differences were observed in all three experiments.
Perception of the weight of a falling ball
Authors: Torii Kenji , Hasegawa Hiroshi
Published: November 2016

Among perceived qualities, perceived weight is connected with the feeling of luxury. Many studies of methods for controlling the perception of weight have been reported; most concern visual and haptic effects, but auditory effects have not been considered. This presentation reports analysis of how the perception of weight changes with changes of visual and auditory stimuli in videos in which a falling ball strikes a flat plate. We made 6 balls and 4 plates of different materials with the same size but different weights. We made 24 sets (6 balls × 4 plates) and recorded scenes in which each ball struck each plate. Eleven subjects evaluated the perception of the weight of the ball on a scale of 1 to 7 in all 552 pairs of video comparisons (24 × 23). Scheffé’s paired comparison test revealed that not only visual stimulus but also auditory stimulus can affect the perception of weight.
Influence of sound source arrangement on the precedence effect
Authors: Abe Koji , Takane Shouichi , Nishiguchi Masayuki , Watanabe Kanji
Published: November 2016

As such robot audition, problem of estimating the direction of the sound image from the physical sound signal has high necessity. In order to develop an estimation system of the direction of sound image corresponding to the multiple sound sources, it is necessary to know the behavior of the precedence effect in comprehensive sound source arrangement. So, we investigated the influence of the sound source arrangement on the precedence effect experimentally. The minimum angle between the directions of two sound sources is 30 degrees. Experimental method is a three Alternative Forced Choice Task. The three choices are in the direction of two sound sources and its intermediate. In the case of a bilaterally symmetrical arrangement of sound sources, our experimental results were in good agreement with the findings obtained in previous studies. However, our experimental results show that deviation of the localized direction of sound image is dependent on the sound image arrangement. Particularly, in the case of left-right asymmetrical and front-back symmetrical arrangement, shift of a sound image direction with respect to time difference had a characteristic trend.
Effect of age and hearing loss on spectral integration and speech identification
Authors: Shrivastav Mini N. , Eddins David
Published: November 2016

The goals of the project were to determine how advancing age and hearing loss affect the integration of acoustic features across the audio-frequency spectrum. Several experiments were designed to test listener’s abilities to either combine or compare intensive and spectral information in non-speech and speech stimuli across frequency channels, and the association between spectral integration and speech recognition. Listeners included were 16 young normal-hearing, 16 older normal-hearing, and 16 older hearing-impaired individuals. The results indicate that age and/or hearing loss impact aspects of feature encoding as well as the ability to combine intensive information across channels. Also, age-related but not hearing-loss-related deficits were observed in spectral integration of temporal information with deficits in encoding as well as the ability to compare temporal information across channels. Taken together, the results are consistent with the notion that age- and hearing-loss-related deficits in spectral integration have both peripheral and central components. Results also indicate that the ability to finely discriminate intensive and temporal changes across frequency may not be strongly associated with the ability to recognize meaningful speech, even though speech is also comprised of dynamic changes in intensive and temporal features.
A neural network model for top-down regulation of sensory plasticity
Authors: Zhang Yu-Xuan , Tang Dinglan , Xiong Ying-Zi , Yu Cong
Published: November 2016

Auditory cortex displays remarkable plasticity, but how such plasticity relates to human perceptual learning remains unclear. Here, we present a neural network model that attempts to link the two. The model consists of an encoding layer, a decoding/decision layer, and an interneuron that receives both top-down regulation and bottom-up stimulation. The interneuron, once activated, implements a neural learning mechanism such as reorganization of the tonotopic map or lateral inhibition. During active training, top-down regulation sensitizes the interneuron and initiates the learning process. Depending on the relative influence of top-down regulation and bottom-up stimulation, learning ranges from partially to completely stimulus specific, consistent with empirical observations. For stimulus-specific learning, we have recently shown that passive exposure to an untrained frequency after, but not before active training induces transfer to that frequency. The model displays similar behaviors regardless of the specific neural learning mechanism (remapping or inhibition) implemented. Overall, the simulation results indicate that auditory cortical plasticity is subject to top-down regulation and that the plasticity, once unlocked, can afford perceptual learning with bottom-up stimulation only.
Assessment of the middle-ear assumption of the auditory hazard assessment algorithm for humans
Authors: Jones Heath G. , Greene Nathaniel T. , Fasanya Bankole K. , Hollonbeck Sean A. , Ahroon William A.
Published: November 2016

The Auditory Hazard Assessment Algorithm for Humans (AHAAH) is an electrical equivalence model of the human ear designed to reproduce sound transmission from the outer into the inner ear in order to predict potential injury from a given sound exposure. This model was generated and validated using a (mostly) feline model, thus several key assumptions may not hold when adapted to the human. The current project aims to test some of these assumptions, such as the effects of middle-ear muscle contraction (MEMC) on sound transmission and whether the MEMC can be elicited by a conditioning stimulus prior to sound exposure (i.e., a “warned” response). In order to quantify the MEMC, we use laser-Doppler vibrometry to measure tympanic membrane motion in response to a reflex-eliciting acoustic impulse. After verifying the MEMC, we will attempt to classically condition the response by pairing the reflex-eliciting acoustic impulse (unconditioned stimulus, UCS) with a light from a LED display (conditioned stimulus, CS). Changes in the magnitude and/or time-course of the MEMC following repeated UCS-CS pairings will be evidence of MEMC conditioning. Validation of these effects will allow updates to Damage-Risk Criteria to better protect the hearing of Soldiers and civilians exposed to high-level impulsive noises.
Estimation of auditory compression and filter shape of elderly listeners using notched noise masking
Authors: Matsui Toshie , Irino Toshio , Inabe Hazuki , Nishimura Yuri , Patterson Roy D.
Published: November 2016

Notched-noise (NN) masking and the compressive GammaChirp (cGC) auditory filter have recently been used to estimate auditory compression and filter shape simultaneously with young normal-hearing (NH) listeners. This paper reports an extension of the paradigm to measure compression and filter shape in elderly listeners with a range of hearing losses. Six elderly listeners (65-75 year old, male) participated in a compact NN experiment with one probe frequency, 2.0 kHz. There were 21 NN conditions chosen to maximize sensitivity to compression in the mid-level range. The listeners’ hearing levels (HLs) at 2.0 kHz ranged from 10 to 50 dB. The cGC filter was fitted to the threshold data to derive level-dependent filter shapes of individuals and their cochlear compression functions. The slope of the central portion of the compression function was normal for all of the listeners except the one with the 50 dB HL, whose slope was close to unity (>0.8 dB/dB). The filter bandwidths were marginally wider than those of young NH listeners. Gathering thresholds in the 21 NN conditions took approximately 3 hours per listener. This is acceptable for laboratory studies with the elderly but still somewhat long for clinical applications.
Computer-controlled audiometer's application as an earplug fit-testing tool
Authors: Stefanson J. R. W. , Ahroon William A.
Published: November 2016

Clinical audiometers are usually coupled with a calibrated pair of TDH-39 headphones, supra-aural earphones that rest on a person’s ears. Hearing protector testing with these types of earphones is problematic due to a couple of reasons; the earplug may protrude from the ear canal and come in contact with the earphone thereby alerting the individual that the earplug is likely not inserted adequately or the earphone may impend on the position and affect the seal of the earplug and thereby void any measurement data. Deeper supraural ear-cup cushions were 3D printed for the TDH-39 headphones in order to allow for an insert earplug to be fit-tested without interference. The 3D printed set of ear-cups was calibrated to the computer-controlled audiometer and 20 subjects were tested in the unoccluded and occluded conditions. The differences between the two measurements at each of the seven frequencies tested (i.e., 500, 1000, 2000, 3000, 4000, 6000, and 8000Hz) were averaged across subjects, personal attenuation ratings computed. Results are compared with a commercially available hearing protective device field attenuation estimation system (i.e., fit-check or fit-test system).
What underlies across-channel gap detection: Overview
Authors: Mori Shuji
Published: November 2016

Gap detection, which measures a person’s ability to hear gaps in tones and noises, is commonly used to assess auditory temporal resolution. There are a variety of ways to measure the minimum detectable gap duration, or gap threshold, including across-frequency gap detection (detecting a silent gap between two spectrally different markers) and between-ear gap detection (detecting silence between a leading and trailing maker delivered to separate ears). A topic of particular interest concerns across-frequency gap detection, where the gap threshold has been found to be an order of magnitude larger than that obtained for a within-frequency task. The between-ear task has also been demonstrated to yield much longer gap thresholds than the within-frequency task. A number of studies have attempted to resolve the discrepancies between within-frequency and between-frequency/ear tasks (termed jointly as across-channel tasks), and research is still ongoing with a number of different approaches and avenues: psychoacoustic experimentation, electrophysiological measurements at the brainstem and cortical levels, as well as mathematical modeling. In this talk, I will provide an overview of research on across-channel gap detection, including the studies conducted at our laboratory.
Simultaneously modeling of multiple fluid-structure interaction subsystems of the human vocal folds
Authors: Oakey Ryan M. , Alvarez Eduardo J. , Thomson Scott L.
Published: November 2016

Voice production is a direct result of vocal fold flow-induced vibration. Air from the lungs dynamically interacts with vocal fold tissue to generate self-sustained vocal fold oscillation, which in turn creates a fluctuating pressure field that is the source of sound for voice and speech. In addition to this primary air-tissue interaction that drives vocal fold vibration, other fluid-structure interactions (FSIs) occur within the interior regions of the vocal folds. For example, during voicing, the vocal fold vasculature is subjected to a time-varying displacement field as the tissue vibrates, thereby potentially affecting blood flow dynamics. Additionally, in benign vocal fold lesions comprised of fluid-filled pockets within the vocal folds, known as polyps, there are significant interactions between the fluid within the polyps and the surrounding tissues. The vocal fold system, therefore, potentially consists of multiple subsystems with different types of fluid-structure interactions that are distinct, yet coupled. In this presentation, experimental and computational studies that have focused on simultaneous modeling of these multi-FSI subsystems will be discussed. Methodologies for modeling the various FSI components will be described, sample results will be presented, and current capabilities and limitations of the various approaches will be summarized.
Structural vibration of an elastically supported plate due to excitation of a turbulent boundary layer
Authors: Diaz Jonmarcos , Maki Kevin , Vlahopoulos Nickolas
Published: November 2016

High-Reynolds number turbulent boundary layers are an important source for noise and structural vibration. Indeed small features of a structure can have important influence on the resulting noise and vibration. In this work we develop a new method to couple a high-fidelity fluid solver with a dynamic-finite-element solver for the structure. The flow solver is based on the OpenFOAM opensource CFD toolkit. The fluid solver uses the Large-Eddy Simulation closure for the unresolved turbulence. Specifically, a local and dynamic one-equation eddy viscosity model is employed. The fluid pressure fluctuation on the structure is mapped to the dynamic finite element model with a suitable interpolation routine. A modal decomposition of the dynamic finite-element model is used to reduce the number of degrees-of-freedom of the numerical structural model. The numerical method is validated for the turbulent flow over a flat plate. The plate is elastically supported along its edges, and the turbulence is excited upstream of the plate by the means of a solid obstruction. Results for the structural vibration on the plate will be compared with previously published experimental measurements. Furthermore, the results will be compared with other numerical predictions in which the fluid forcing is determined using statistical methods
English-as-a-second-language speakers’ perception of personality in English speech
Authors: Li Bin , Cui Yingting , Dou Yan , Liu Yan
Published: November 2016

We make inferences on speaker’s personality and emotion from their voices. This study aims at English-as-a-second-language (ESL) speakers’ perception of personality as reflected in public speech online given by native English speakers. Phonetic parameters such as speaking rate and pitch are manipulated and combined in different ways to examine their effects on perceptual judgement of personality and content comprehension. Our ESL listeners are 50 university students who are native speakers of Cantonese and fluent users of English. They answer questions on the content of the speech samples, and also make judgement on various traits of the speaker’ personality. The correct percentage and the judgement scores are recorded and examined for correlation between manipulation types and listening comprehension as well as that between phonetic parameters and perception of personality. Modification to the speaker’s pitch seem in general improve listeners’ comprehension accuracy as well as results in higher scores of personality perception, whereas that to the speaking rate does not show positive influence on speech comprehension or personality judgment. Our findings will provide insights to general phonetics and speech communication, but also pedagogical implications to academic English in nonnative settings.
Perception of speech rate in speech rate perception
Authors: Aldholmi Yahya , Park Hanyong
Published: November 2016

This study investigates what influences a listener’s perception of speech rate. Three factors were investigated: pause type, actual speech rate, and utterance type (native, accented, and unfamiliar). Using manually accelerated vs. decelerated but structurally-identical sentences with three-type pauses (long, short, and filled) in accented, native, and unfamiliar language (Spanish) utterances, a group of Arabic speakers judged whether the sentences they heard were slow or fast, and rated the speed on a 1-7 scale (1 = slow, 7 = fast). The findings show that long pauses triggered lower ratings, while filled pauses achieved ratings higher than both long and short pauses. Unfamiliar language received the highest ratings while the accented speech received the lowest. This suggests that, regardless of actual speech rate, silent pauses affect our perception of speech rate, and that when the duration of silence differs, our perception of speech rate will differ accordingly. The results also show that we tend to think of accented speech as being slower and of unfamiliar speech as being faster even when the two speech samples have the same length and pause types.
English listeners’ judgments of Japanese-accented English vowel productions: Relation to acoustic and kinematic characteristics
Authors: Mehta Sonya , Katz William F.
Published: November 2016

The present study investigates how monolingual English listeners categorize foreign (Japanese) productions of English tense and lax vowels with the aim of relating vowel identification to the acoustic and kinematic vowel space. American English front vowels (/i/, /ɪ/, /e/, /ɛ/, and /æ/) were elicited in /hVd/ context from ten Japanese adults who learned English as a second language (ESL). Listeners categorized these vowel productions in a six-alternative, forced-choice paradigm (including the choice /ʌ/). Vowels produced by two native English speakers were included in the perceptual task for comparison. Preliminary results showed higher perceptual accuracy for tense vowels than for lax vowels. As expected, vowels from English talkers were more accurately identified than those from Japanese ESL speakers. To determine whether listeners’ perceptual categorization corresponded with acoustic and kinematic patterns, perceptual data for contrasting vowel categories were compared with measured differences in formant (F1/F2) and articulatory space. Pilot data suggest a strong relation between acoustic and kinematic measures, but a weaker correspondence between these two data sources and listeners’ perceptual judgments. Additional factors, including the roles of duration, talker and listener variability, and vowel similarity between languages, will be explored.
Transferring cue-weighting from second language into first language: Group trends and individual differences
Authors: Dmitrieva Olga , Conklin Jenna , Nigmatulina Yulia
Published: November 2016

Second language learning has been shown to affect first language production (Flege, 1987; Major, 1992; Sancier & Fowler, 1997, inter alia). Less is known about whether and how experience with another language may affect first language perception. The present study examines the use of preceding vowel duration vs. voicing during closure as cues to word-final and word-medial stop voicing by three groups of listeners: native speakers of American English (34), native speakers of Russian (34), and Russian expatriates in the United States (24). The results suggest that bilingual listeners are transferring a greater reliance on vowel duration, characteristic of English perceptual mode, into native speech categorization. The transfer occurred in word-final condition where vowel duration as a correlate of voicing is of very different importance in the two languages. Individual trends revealed that bilinguals’ reliance on vowel duration may even be exaggerated in native, compared to non-native, speech perception. The use of vowel duration in bilinguals was positively correlated with such individual differences as length of residence in the United States and average amount of speaking English per week. The triggers and possible benefits of such perceptual transfers are discussed in the context of language use in the expatriate communities.
The effects of prenasal raising of American English /æ/ on the identification of American English vowels by native Japanese and Korean listeners
Authors: Nozawa Takeshi , Cheon Sang Yee
Published: November 2016

This study attempts to investigate the effect of prenasal raising of American English /æ/ on the identification of the vowel by native Japanese and Korean listeners by comparing the identification accuracy of /æ/ in preplosive and prenasal context by these two listener groups. Native Japanese speakers generally equate /æ/ with Japanese low vowel /a/ whereas native Korean speakers identify /æ/ with Korean mid front vowel /e/, and /æ/-/ɛ/ is one of the most difficult English vowel pairs for Korean speakers to discriminate (Ingram & Park 1997, Frieda & Nozawa 2007). It was expected that Korean listeners would identify raised /æ/ in prenasal context as /ɛ/ or /eɪ/, but they mistakenly identified /ɛ/ and /eɪ/ as /æ/ far more frequently than /æ/ as /ɛ/ or /eɪ/. The results revealed that while Japanese listeners' identification accuracy of /æ/ is significantly lower in prenasal context than in preplosive context, Korean listeners' identification accuracy of /æ/ is unaffected by the raising of /æ/. Korean listeners far more often mistakenly identify /ɛ/ as /æ/ in preplosive context than the other way around, and this tendency stays the same even when /æ/ is raised in prenasal context.
The effects of acoustic and lexical factors on perception of accented speech
Authors: Tzeng Christina Y. , E.D. Alexander Jessica , Nygaard Lynne C.
Published: November 2016

Foreign-accented speech differs from native pronunciation on a variety of spectral and temporal properties that affect both accentedness and intelligibility. The specific acoustic correlates, however, as well as the role of signal-independent lexical characteristics on accentedness judgments and intelligibility, remain unclear. The current study examined the potential contribution of particular acoustic (F1, F2, duration) and lexical (frequency, neighborhood density) factors to native speakers' ratings of accentedness and assessments of intelligibility for English words spoken by native Spanish speakers. Previous research has found that in native English speech, hard words (low frequency, high neighborhood density) have more dispersed vowel spaces relative to easy words (Pardo et al., 2013). Preliminary findings in the current study indicate the opposite pattern such that foreign-accented easy words exhibited more vowel dispersion than hard words. Further, vowel dispersion measures for easy, but not hard, words predicted accentedness and intelligibility such that as speakers' vowel spaces became more dispersed, the more accented and less intelligible their utterances were rated. Together, these findings suggest that signal-dependent and signal-independent factors have differential effects on the production and perception of accented versus native speech, implying a complex relationship between acoustic and lexical properties that is unique to foreign-accented speech.
Effects of native language on the use of segmental and suprasegmental cues to stress in English word recognition: An eye-tracking study
Authors: Connell Katrina , Hüls Simone , Martínez-García Maria Teresa , Qin Zhen , Shin Seulgi , Yan Hanbo , Tremblay Annie
Published: November 2016

This study investigates whether the presence of lexical stress in the native language (L1) determines second-language (L2) learners’ ability to use stress in L2 lexical access. It focuses on (standard Mandarin) Chinese and (Seoul) Korean listeners’ (and native English listeners’) use of segmental and suprasegmental cues to stress in English word recognition. Stress placement in English is signaled by segmental (vowel reduction) and suprasegmental (fundamental frequency, duration, and intensity) cues. Chinese has full-full and full-reduced words that differ in stress placement, with segmental and suprasegmental cues signaling stress. By contrast, Korean does not have lexical stress. Participants completed an eye-tracking experiment. They heard stimuli containing a target word with initial stress (parrot), and saw four orthographic words in the display, including the target and one of two competitors (stress match: parish; stress mismatch: parade). The first syllable of the target and stress-mismatch competitor differed in both segmental and suprasegmental information (parrot-parade) or only in suprasegmental information (mystic-mistake). Growth-curve analyses on fixations revealed that only Chinese and English listeners used stress to recognize English words, confirming L1 effects on the use of stress in L2 lexical access. Furthermore, only English listeners made greater use of stress in the presence of vowel reduction.
Informational masking of six-talker babble on Mandarin Chinese vowel and tone identification: Comparison between native Chinese and Korean listeners
Authors: Xu Can , Zhang Hui , Wang Yuxia , Ding Hongwei
Published: November 2016

The goal of this study was to investigate the informational masking (IM) of Mandarin six-talker babble on Mandarin vowel and tone perception for native Chinese and Korean speakers with high and medium Mandarin proficiency. Mandarin Chinese speech sounds (vowel plus tone) were presented in quiet and two noises: six-talker babble and babble-modulated noise, which was spectrally and temporally matched with babble. The IM was computed as the difference in the identification scores between the two types of noises. Overall, all the four factors (listener group, noise type, vowel-plus-tone category, and SNR) significantly affected participants’ identification of Mandarin stimuli. Particularly, in both quiet and noisy conditions, Chinese listeners had comparable performance with Korean listeners with high Mandarin proficiency, while Chinese listeners significantly outperformed Korean listeners with medium Mandarin proficiency. However, no significant difference was found in IM among the listener groups. In conclusion, at the syllabic level, highly-proficient Korean listeners had native-like performance of Mandarin vowel and tone identification in quiet and noise, whereas Korean listeners with medium proficiency had greater difficulty, specifically in noise, likely due to their lower capacity to process phonemic and tonal information, rather than the IM of babble.
Pitch accents in the Spanish of Japanese-Spanish bilinguals
Authors: Flores Tanya
Published: November 2016

This study examines supra-segmental traits in the Spanish speech productions of thirteen Japanese L1—Spanish L2 speakers living in Valencia, Spain. The analysis presented here will focus on the use of pitch accents and final syllable lengthening. The data in this study shows speakers using Japanese pitch accent patterns in Spanish words, often as the only phonetic indicator of second language speech. The goal of this study is to identify specific Japanese pitch accent patterns used and determine if and how they are systematically transferred into Spanish. Following the autosegmental-metric model (SpToBI), pitch accents will be measured using Praat. Findings will contribute to the currently limited acoustic research on supra-segmental or prosodic traits of L2 speech in language contact situations.
Japanese singleton and geminate stops mispronounced by non-native speakers
Authors: Yamakawa Kimiko , Amano Shigeaki
Published: November 2016

Non-native Japanese speakers often mispronounce Japanese singleton and geminate stops. However, it has been unclear how durations of speech segments in their mispronunciation differ from those of correct pronunciation by native Japanese speakers. This study analyzed mispronunciation of singleton and geminate stops by non-native speakers (8 English, 12 French, and 10 each of Korean, Taiwanese, Thai, and Vietnamese). Non-native speakers' mispronunciations were identified based on 10 native Japanese speakers' production boundary between singleton and geminate stops. It was revealed that when non-native speakers mispronounce a singleton stop as a geminate stop, stop closure is longer whereas its previous mora is shorter than in native speakers' correct pronunciation. Meanwhile, when non-native speakers mispronounce a geminate stop as a singleton stop, stop closure is shorter whereas its following mora is longer. These findings indicate that non-native speakers’ mispronunciations are caused not only by the durations of closure but also by the lengths of the previous/following mora. [This study was supported by JSPS KAKENHI Grants Number JP 25284080, 26370464, 15H03207, and 16K13221. It was also supported by a special-research grant of Aichi Shukutoku University in 2015-2016.]
Non-native perception and production of lexical tones before and after high-variability training
Authors: Chen Yan
Published: November 2016

This study investigates non-native perception and production of lexical tones. 26 English speakers received 3 hours of high-variability AX training to perceive tonal contrasts in Cantonese. Half of them were trained with additional iconic tone marks (AV) and half of them were not (AO). Pre-test and post-test were conducted and both of them consisted of high-variability AXB followed by delayed repetition using the stimuli from AXB. Preliminary results showed that T2 (high-rising) vs. T5 (low-rising) and T3 (mid-level) vs. T6 (low-level) were the most difficult pairs in AXB, with about 70% correct for T2-T5 and slightly above chance performance for T3-T6 in post-test. AV listeners did not achieve significantly higher accuracy than AO listeners. In delayed repetition, both groups produced distinct contours for T2 and T5 and for T3 and T6 even in pre-test, which did not differ significantly from post-test. Exposure to pre-test AXB might have facilitated talker normalization and tone production in the delayed repetition task. In addition, AV subjects had slightly more semitone difference in the second half of rhyme (offset—50% of rhyme duration) for T2 in post-test than AO subjects, but this effect of iconic visual information is limited.
Lexical training using accented speech improves non-native contrast discrimination
Authors: Viswanathan Navin , Olmstead Annie J.
Published: November 2016

Native American-English (AE) listeners have difficulty distinguishing between dental and retroflex stop consonants. For example, when asked to classify voiceless retroflex and dental stops, AE listeners typically label both items as the alveolar /t/. While AE lacks the dental-retroflex distinction, varieties of Indian English (IE) use this contrast to instantiate the AE /t/-/ð/ distinction (tanks vs. thanks). Specifically, the dental /t̪/ is used in instances where /ð/ would be used in AE while the retroflex /ʈ/ is used in place of /t/. This situation provides us with the opportunity to present the dental-retroflex difference in naturally produced tokens of English. In the current set of experiments, we examine the effect of exposure to IE tokens on AE listeners’ discrimination of /t̪/ and /ʈ/. Participants transcribed English words spoken by an IE speaker. The critical items were words that began with either /t/ (e.g., take), /ð/ (e.g., thorough), or were /t/-/ð/ minimal pairs (tanks vs. thanks). An AXB discrimination task performed before and after the transcription showed that AE speakers improved in their discrimination of /t̪/ and /ʈ/ after transcription. Subsequent studies examine this learning effect to investigate the role of specific lexical contexts and of speaker-specific information.
Adaptation and aftereffects in response to bite block perturbation
Authors: Myers Brett , Mefferd Antje
Published: November 2016

Although speakers can instantly adapt to the presence of a bite block (BB), they also refine their compensatory behavior over time. However, the extent to which BB perturbations elicit aftereffects and the mechanisms that contribute to refinement and aftereffects remain unknown. In this study, speakers belonging to either a practice or a no-practice group produced sentence repetitions under five conditions: PRE-BB (jaw-free), BB1 (jaw-fixed, initial BB exposure), BB2 (jaw-fixed, after 20 minutes of BB exposure), POST1 (jaw-free, immediately after BB removal), POST2 (jaw-free, one minute after BB removal). All speakers held a 10mm BB in place for 20 minutes with the practice group reading aloud and the no-practice group sitting quietly. Jaw and posterior tongue kinematics were examined during the vowel /i/ embedded in the word “please” using electromagnetic articulography. Preliminary findings (14 speakers) revealed a significant main effect of condition only. That is, relative to PRE-BB, tongue height did not significantly change during BB1 and BB2 (indicating successful adaptation), but significantly increased during POST1 and POST2 (indicating an aftereffect). Jaw height remained unchanged from PRE-BB to POST1 and POST2 (indicating no aftereffect). Findings will be discussed with regard to internal models and the roles of proprioceptive and acoustic feedback.
Three-dimensional image reconstruction of objects using synthetic aperture sonar
Authors: Plotnick Daniel , Marston Timothy M.
Published: November 2016

Synthetic aperture sonar imaging is typically considered for the case of linear or circular scans, where the reconstructed acoustic image is a two-dimensional representation of the true three-dimensional scattering from some object. However, a multi-dimensional aperture may be used to create a 3-D or volume image reconstruction of the acoustic scattering by that object. The 3-D image reconstruction may be performed using a delay-and-sum algorithm, or using comparatively fast wavenumber based methods. Simulated point scatterers will be used to initially demonstrate the algorithms, followed by a demonstration involving a simple object near a reflecting boundary. For objects that are located close to a reflecting boundary there exists a rich 3-D scattering structure. When imaged in two dimensions, object features becomes distorted due to the projection of scattering loci (e.g. the broadside reflection from a cylindrical target) that may be located outside of the image plane [Plotnick et al., J. Acoust. Soc. Am. 139, 2053 (2016)]. Volume images of such targets move these scattering loci to new locations in 3-D space, which may aid in understanding the target’s shape and orientation. The point spread function and 3-D sampling requirements will also be considered.
The Advanced Synthetic Aperture Sonar Imaging eNgine (ASASIN), a time-domain backprojection beamformer using graphics processing units
Authors: Gerg Isaac
Published: November 2016

We present a synthetic aperture sonar beamforming engine called ASASIN. ASASIN is a graphics processing unit based time-domain backprojection beamformer for Windows and Linux utilizing the NVIDIA architecture. It supports arbitrary array geometries and has a modular data input system. ASASIN uses one or more graphics processing units to beamform synthetic aperture sonar data faster than real-time. Its interface is suitable for operators and research scientists. In this talk we discuss ASASINs algorithms and computational performance along with the choices confronted (both algorithmic and computational) in its design. Finally, we discuss its computational performance across a variety of NVIDIA graphics processing units including their embedded models.
Spatial dependence of very low frequency wind-generated noise in the sound channel
Authors: Nichols Stephen M. , Bradley David L.
Published: November 2016

Storm-driven non-linear interaction of ocean waves excites Very Low Frequency (VLF) (<5 Hz) sounds locally. As the surface wind speed increases, the slope of the VLF acoustic spectrum approaches approximately -20 dB/octave, corresponding to a similar behavior observed in the surface wave spectrum. The amplitude of the measured acoustic spectrum in this frequency region is strongly correlated with local surface wind speeds [J. Acoust. Soc. Am. 139(3), 1110 (2016)]. Due to the sound propagation conditions in the open ocean, it is expected that sound from distant storms will also provide a significant contribution to the measured sound field. The impact of distant meteorological activity on the local acoustic spectrum is examined by comparing the ambient noise recorded by the Comprehensive Nuclear-Test Ban Treaty Organization’s (CTBTO) hydro-acoustic monitoring system to global records of surface wind speed, remotely sensed via satellite.
Presence of ribbon seal vocalizations are related to sea ice extent in the Nemuro Strait, the Okhotsk Sea
Authors: Otsuki Mayuko , Akamatsu Tomonari , Nobetsu Takahiro , Mitani Yoko
Published: November 2016

Vocalizations of ice-breeding ribbon seals Histriophoca fasciata were recorded using underwater passive acoustic methods from November 2012 to March 2014 off the Nemuro Strait, Japan. Seal presence in the strait was examined in relation to the sea ice extent in the Okhotsk Sea. Ribbon seal downsweeps were only detected when sea ice was present in the strait (February and March), with more detections in March leading up to the spring breeding season. Since ribbon seals require ice for breeding, underwater communication for breeding could be needed during the sea ice presence in this strait. Northeasterly winds were another indirect driver of ribbon seal occurrence, since winds from this direction likely transport sea ice from the central Okhotsk Sea into the Nemuro Strait. Downsweep detections decreased in the middle of the day, which is consistent with observations that seals hauled out on the ice during this time, and thus were producing fewer underwater vocalizations. Our results suggest that a decrease in the sea ice extent in the Okhotsk Sea may change the distribution of ribbon seals and impact their breeding behaviour since the Nemuro Strait region of the Okhotsk Sea is likely the southern limit of their breeding range.
Effect of sand and silt particles on the attenuation of compressional waves in marine mud sediments
Authors: Pierce Allan D. , Siegmann William L. , Brown Elisabeth
Published: November 2016

Mud in marine sediments is a mixture of clay, sand, and silt particles. Present paper follows up on a suggestion by Holland and Dosso (JASA, 2013) that the variability of the measured frequency-dependent compressional wave attenuation may be caused by the variability of the amounts of sand and silt particles. The premise is that the porosity for the mud is high and that the sand and silt particles are in suspension. They do not settle out to the bottom of the layer because the card-house fabric of the clay particles tends to hold them in place. This supposition leads to a theory where the clay configuration gives a base-line attenuation, and the contribution from the individual sand and silt particles is additive. The estimation of the latter is distinguished from the existing theories of attenuation of sound in sandy/silty sediments in that the particles are presumed not to touch each other. Particles are assumed to be spherical and there is no slip between particle surfaces and the surrounding water. Earlier theories of attenuation in suspensions by Lamb (Hydrodynamics), Urick (JASA. 1948), and others are criticized because of their assumption that vorticity in fluid is zero. The present theory predicts that the attenuation contribution from a given category of particle is proportional to the square of the frequency and to square of particle diameter, and inversely proportional to the viscosity, in the limit of low frequencies. It approaches a frequency-independent constant at higher frequencies. [Work supported by ONR.]
On using multi-look synthetic aperture sonar analysis for the investigation of scattering mechanisms
Authors: Lyons Anthony P. , Brown Daniel C.
Published: November 2016

Multi-look coherence explores the information content of synthetic aperture sonar (SAS) images by splitting the total angle and frequency spectral bandwidth of a complex SAS image into sub-bands. In the presence of a random distribution of surface or volume scatterers, the spectral coherence is proportional to the degree of overlap in sub-bands of the SAS image. Consequently, for a perfectly random distribution of scatterers, the spectral coherence should be zero when the sub-bands do not overlap. If the scatterer distribution deviates from this basic random distribution, the spectral coherence may be non-zero for special cases that would be related to scattering from specific structures such as points or facets. For that reason it appears to be possible to separate coherent features from the random scattered background signal using spectral coherence, suggesting possibilities for detecting and/or characterizing objects (especially in low signal-to-reverberation situations). In this talk, we will discuss the concept and the utility of using the complex coherence between a series of sub-look SAS images to investigate different scattering mechanisms as well as show examples of the technique using real and modeled SAS data. [Work performed under ONR Grants N00014-16-1-2469 and N00014-16-1-2313.]
Audio service for elderly people in broadcasting
Authors: Komori Tomoyasu , Sugimoro Takehiro , Imai Atsushi
Published: November 2016

Elderly viewers sometimes feel that the background sound (music and sound effects) in television programs is too loud or that the narration or speech is too fast to understand. We attempted to solve these problems by two methods: improvement of the receiver system and the development of a new broadcasting system. We prototyped a receiver system in which loudness balance between the dialog (narration or speech) and background sound can be adjusted, as well as the speech rate. The results of subjective evaluation experiments with elderly viewers showed that the use of this system could significantly facilitate listening to television sound. In 2016, we started test broadcasting of 8K Super Hi-Vision (8K SHV) programs that have highly immersive surround sound produced through 22.2 multichannel (22.2ch). With the aim of improving the functionality of 8K SHV sound as a broadcasting service, a domestic standard has been established for the dialogue control functions, including the dialog enhancement and a dialog replacement function. In this presentation, we show these two types of audio service for elderly people.