bluuebunny/crossref_metadata_2025 huggingface dataset:
Infrasound propagation in multiple-scale random media using generalized polynomial chaos
Authors: GOUPY Alexandre , MILLET Christophe , LUCOR Didier
Published: April 2019

Infrasound propagation in realistic environments is highly dependent on the information to specify the waveguide parameters. For real-world applications, there is considerable uncertainty regarding this information, and it is more realistic to consider the wind and temperature profiles as random functions, with associated probability distribution functions reflecting phenomena that are filtered out in the available data. Even though the numerical methods currently-in-use allow accurate results for a given atmosphere, high dimensionality of the random functions severely limits the ability to compute the random process representing the acoustic field, and some form of sampling reduction is necessary. In this work, we use polynomial chaos (gPC)-based metamodels to represent the effect of large-scale atmospheric variability onto the acoustic normal modes. The impact of small-scale atmospheric structures is modelled using a perturbative approach of the coupling matrix. This multi-level approach allows to estimate the statistical influence of each mode as the frequency varies. An excellent agreement is obtained with the gPC-based propagation model, with a few realizations of the random process, when compared with the Monte Carlo approach, with its thousands of realizations. Furthermore, the gPC framework allows computing easily the Sobol indices without supplementary cost, which is essential for sensitivity studies.
Dependence of Rayleigh integral predictions on the ground motion model for acoustic signals produced by underground explosions
Authors: Blom Philip
Published: April 2019

Seismoacoustic signatures are produced by above- and below-ground explosions and are often observed at local, regional, and global distances. In the case of an underground explosion, seismic waves propagate to the surface and produce acoustic signatures via pumping of the atmosphere by the ground motion that can be predicted using a Rayleigh integral analysis. Acoustic signature predictions will be discussed and compared with observations from the Source Physics Experiment (SPE) in two scenarios. First, a rigid piston model of the ground motion will be highlighted as a first order model. Second, a more realistic model treating the ground as an elastic medium with finite compressional wave speed will be developed and discussed to demonstrate how such a model changes predicted acoustic signals at local distances. Acoustic signals predicted using each methodology will be compared with observations from SPE to identify how characteristics of the acoustic signal can be leveraged to improve characterization of the underground explosive source.
Diffuse ultrasonic transport in an unconsolidated glass bead pack
Authors: Weaver Richard , Yoritomo John Y.
Published: April 2019

We study the transport of diffuse ultrasound with frequencies of hundreds of kHz through random aggregates of d = 3.0 and 1.0 mm diameter spherical glass beads in air under static loads of 100 to 300 kPa. Highdensity polystyrene foam on top and bottom transmits the static loads while maintaining ultrasonic isolation. A floating polystyrene foam wall helps establish a uniform hydrostatic load through the 10 to 70 mm depths. Findings include a band gap extending—for the 3 mm beads—from a lower edge at about 200 kHz (that scales weakly with load and inversely with bead diameter.) Amongst the 3mm beads, we observe an upper edge to the band gap at about 900 kHz corresponding to an optical branch passband associated with the lowest internal resonance of an isolated bead. Higher optical branches are observed also. The lower edge at 200 kHz corresponds well with estimates of the upper band edge for the rotational-wave vibrations of a hexagonal close packed array of beads in Hertzian contact. The observed first arrival times correspond well with Hertzian predictions for low frequency effective longitudinal wavespeeds. Within the low frequency pass band we see diffuse transport, with diffusivities comparable to simple theoretical expectations.
An outdoor sound propagation model in concert with geographic information system software
Authors: Tipton Nathan D. , Sparrow Victor
Published: April 2019

As industrial technology advances, man-made noise has increasingly contributed to natural environment soundscapes. To predict how this anthropogenic noise can affect these natural environments, engineers build acoustic models over given terrain; however many current models are not compatible with common Geographic Information System (GIS) software, could become outdated due to software version updates, or are written as proprietary packages unavailable to park management. The goal of this study was to create a true open source outdoor sound propagation model compatible with (but not dependent on) outside GIS software. The model was developed to include uneven terrain, atmospheric absorption, screening, wind effects, and ground effects using ISO 9613-2, an international standard for attenuation of sound during propagation outdoors. Given sound source inputs and locations over an input Digital Elevation Map, GIS compatible file types of spatially explicit sound pressure level predictions can be produced by this model. This tool allows for ecologists and park managers to get a better understanding of how anthropogenic noise is affecting soundscapes in natural environments. [Work supported by United Technologies Corporation Professorship.]
Cortical reorganization following auditory spatial training in listeners with sensorineural hearing impairment: A high-density electroencephalography study
Authors: Nisha K. V. , Kumar Ajith U.
Published: April 2019

The present study is intervention-based research aimed at remediation of spatial deficits in listeners with sensorineural hearing impairment (SNHI), through the use of virtual acoustic technology. A mixed group design comprising both within (pre-test, post-test control group design) and across the groups (standard group) comparisons were performed. The study included 37 participants, who were divided into three groups. Groups I and II consisted of SNHI listeners, while group III comprised normal hearing (NH) listeners. The study was conducted in three phases. At the pre-training phase, electroencephalographic (EEG) recordings were acquired from all the three groups using spatial deviants presented in P300 paradigm. Following this, group I listeners underwent virtual acoustic space training (VAST), and post-training EEG recordings were obtained. EEG recordings were also acquired from group II listeners in second evaluation without subjecting them to any formal spatial training. Results of unpaired t-tests, grand average waveforms and scalp topographies of offline processed waveforms revealed significant differences between SNHI and NH listeners. Furthermore, spatio-temporal analyses showed the emergence of new scalp maps in post-training phase in trained listeners and no topographic changes in untrained SNHI group, suggestive of benefit derived from VAST right at the fundamental level (cortical) of spatial processing.
Influence of semantics on the perception of gender and femininity
Authors: Piol Serena , Levi Susannah V.
Published: April 2019

Research on the perception of femininity of a speaker has either focused on acoustic parameters (e.g., F0) or on lexical differences (e.g., mauve/purple). This study simultaneously examined how acoustic parameters and semantic content affect the perception of a speaker’s gender and femininity. Three speaker groups (cismen, ciswomen, and transwomen) produced sentences that were categorized as containing masculine lexical items (e.g., The boy gave the football a kick), feminine items (e.g., The little girl cuddled her doll), or neutral items (e.g., Airmail requires a special stamp). Listeners were first asked to identify the gender (male/female) and then asked to rate femininity on a visual analog scale. Results revealed no significant differences in femininity based on the lexical category of the sentences. Consistent with previous findings, average F0 predicted femininity ratings. Despite previous research showing differences in speaking rate for cismale and cisfemale speakers, our data revealed no effect of speaking rate on femininity rating.
Dialect-specific features enhance perception of phonetic imitation of unfamiliar dialects
Authors: Ross John P. , Lilley Kevin D. , Clopper Cynthia G. , Pardo Jennifer , Levi Susannah V.
Published: April 2019

Talkers reproduce speech features of their interlocutors through phonetic imitation. In this study, the effects of experience with a dialect on phonetic imitation and the perceptibility of that imitation were explored. Talkers with New York City and General American accents repeated isolated words after model talkers with New York City and General American accents in a shadowing task. Half of the target words contained phonetic features differing between the two accents, including the stressed vowel in words like "cauldron," the stressed vowel in words like "carriage," and the initial fricative in words like "stranger." The other half contained no distinguishing dialect features. Participants from the Midwestern United States completed an AXB task assessing the perceptual similarity of the repeated words to the original stimuli. The results demonstrated that accuracy was above chance overall, suggesting imitation across shadower and model talker accents. Additionally, a significant interaction between the presence of dialect-specific features and shadower dialect was observed: the presence of dialect-specific features facilitated identification of imitations by New York City shadowers, but had no effect on identification of imitations by General American shadowers. These findings suggest that the perception of phonetic imitation of unfamiliar dialects is enhanced by iconic dialect features.
Speech exposure familiarizes listeners with talkers’ vocal identity
Authors: Lee Jayden , Perrachione Tyler K.
Published: April 2019

Talker identification experiments typically explicitly train listeners to identify voices. Ecologically, however, listeners learn to identify talkers without explicit practice. Here, we investigated whether listeners gain familiarity with voices even when they are not explicitly identifying them. Participants were assigned to three different exposure tasks with feedback, exposing them to identical stimuli but differentially directing their attention between talkers’ vocal identity and verbal content: (1) identifying whether the talker and visual cue on each trial matched; (2) discriminating whether the talker was the same as the prior trial; (3) discriminating whether the speech content matched the previous trial. All three groups were then tested on their ability to learn to identify talkers from novel speech content. Critically, we manipulated whether the talkers during this post-test were the same or different than those heard during training. Regardless of exposure task, listeners were significantly more accurate at learning to identify talkers they had previously been exposed to versus novel talkers. The group that practiced identifying talkers during the exposure phase was only more accurate on exposed talkers. These results suggest that listeners learn talkers’ vocal identity during speech perception even if they have not been directed to attend to talker identity.
Speaking rate changes how duration informs phoneme categorization
Authors: Lamont Andrew , Yin Rong , Naik Aneesh , Kingston John
Published: April 2019

Repp et al. J. Exp. Psychol. (1978)] reported that for a given duration of fricative noise, a longer silence was required to shift from a fricative to an affricate percept at a slower than a faster speaking rate. We crossed 5 fricative durations (90–208 ms, 29–30 ms steps) by 5 silence durations (0–120 ms, 30 ms steps) by two speaking rates (slow:fast ratio 1.51). Possible responses were "grey ship," "grey chip," "great ship," or "great chip." The likelihood of responding "ch" relative to "sh" decreased as the fricative lengthened, increased as the silence lengthened, and was more likely at the slow than the fast rate, but neither fricative nor silence duration interacted with speaking rate \--- an apparent failure to replicate Repp, et al. The likelihood of responding "great" relative to "grey" increased with both fricative and silence duration and at the faster than the slower rate. Increasing fricative duration also increased the relative likelihood of responding "great" more at the slower than the fast rate, but increasing silence duration increased "great" likelihood less at the slower rate, which indirectly replicates Repp et al., so long as fewer stop responses stand in for fewer affricate responses.
Adaptive measurement of crossover frequencies for intelligibility prediction
Authors: Whitmal Nathaniel A.
Published: April 2019

In SII theory, frequencies where speech spectra can be divided into two equally-intelligible subbands are called crossover frequencies. These frequencies play a crucial role in SII calculations, and also designate spectral regions that contain important speech recognition cues. Typically, crossover frequencies are found by measuring psychometric curves for speech processed by a series of low-pass and high-pass filters, and then finding the two curves’ intersection: an inefficient, time-consuming process. The present study introduces an up/down quantile estimation algorithm that adaptively steers filter cutoff frequencies toward the crossover frequency. Changes in cutoff frequency are governed by comparisons of block trials for low-pass and high-pass filtered speech that meet theoretical requirements for convergence toward the crossover frequency. Preliminary results for trials with nonsense syllables show that the proposed method’s estimates match those obtained in published trials using the conventional method. Applications in SII measurements and speech recognition cue measurement will be discussed.
Facilitation of speech processing by both expected and unexpected talker continuity
Authors: Carter Yaminah D. , Kapadia Alexandra M. , Lim Sung-Joo , Perrachione Tyler K.
Published: April 2019

Speech processing is faster for one continuous talker than mixed talkers. However, it is unknown whether listeners’ expectations about talker continuity affect this facilitation. We measured response times during three speeded word identification experiments that manipulated listeners’ expectations about talker continuity. First, we manipulated expectations about talker continuity by presenting words in pairs where both words were frequently produced by the same talker (talker-repeat trials) and rarely by different talkers (talker-change trials), or vice-versa. Word identification was faster in talker-repeat trials than talker-change trials, with equal facilitation from both expected and unexpected talker continuity. Unexpected talker changes did not slow processing more than expected changes. Second, a control experiment demonstrated that listeners’ expectations about repetitions of the word itself did affect word identification speed. Third, listeners identified words in conditions with one talker, two talkers presented randomly, or two alternating talkers. Word identification was faster whenever the talker was repeated compared to when the talker switched between trials, even if listeners could perfectly predict the talker switch (i.e., alternating-talker condition); talker continuity also facilitated word identification in the random condition. These results provide converging evidence that talker continuity facilitates speech processing in an automatic, feed-forward way, irrespective of listeners’ expectations.
Restaurant acoustics—Unconducted and sometimes unintended orchestrations—An overview
Authors: Bray Wade
Published: April 2019

The modern restaurant, such as the modern concert hall, is a societal orchestration on many levels including and involving acoustics. The restaurant overlays a business approach, diner tastes, architecture, and other socio-economic factors in superimposed circles of interaction thought to be planned but in action often unanticipated with unwitting consequences. The n-dimensional influences of restaurant acoustics have distinct parallels with the n-dimensional influences of concert hall acoustics. In a concert hall, it is not enough to have architectural beauty, a quiet background and good acoustics in the audience area if onstage acoustics do not support the musicians as individuals in an ensemble. If players must expend concentration on coping instead of elevating unhindered into their art, the quality the audience desires of the music cannot be reached. But if both onstage and audience area acoustics are good, the music soars, audiences keep coming and paying, all participants reap positive rewards, and the organization is successful and self-perpetuating. In this overview, we suggest that the influence of a restaurant’s acoustics on its success/satisfaction outcome is perhaps even more complex with more human dimensions and less known than that of the concert hall but that observing and considering these parallels may be beneficial.
Characterization of restaurant soundscapes based on logged sound levels and occupancy measurements
Authors: Smith Kieren H. , Anderson Victoria R. , Wang Lily M.
Published: April 2019

Sound levels in a restaurant depend on a variety of factors including the restaurant’s room shape, materials, seating layout, and the levels of ambient and human-produced noise. To better understand the characteristics of restaurant acoustics in real world settings, an in situ study has been undertaken in a sampling of sit-down dining venues. Assorted geometric room characteristics, impulse responses, and background noise data were gathered from the spaces. Sound levels were also logged in the restaurants during operating hours simultaneously with occupant count and density using thermal imaging. The gathered data are analyzed to characterize the soundscapes of some existing restaurants. In particular, the research aims to understand how sound levels increase with occupancy and how specific architectural and design features such as seating style and density may contribute to experienced sound levels.
Mosquito hearing is the most sensitive among arthropods—But is the sound level of a male swarm loud enough to be picked up by the female’s particle-velocity sensor?
Authors: Feugère Lionel , Gibson Gabriella , Roux Olivier
Published: April 2019

Males of many mosquito species aggregate in station-keeping swarms, waiting for the arrival of conspecific females to mate with. We test whether audition could be used by a female to locate male swarms and to assess whether the males are conspecific. The sound level resulting from thousands of wing flaps could be loud enough to be heard at a long range (~1 m) via the antennal flagellum (particle velocity sensor, primarily designed for close-range communication). A mosquito hears a conspecific by adjusting its own wing-beat frequency so that the difference tone between its own and the opposite-sex frequencies falls into a narrow band to which the auditory organ is tuned. Indeed, the antennal flagella produce distortion products resulting in difference tones of the nearby soundscape. Swarmsof males were recorded and played-back to females in a 2-m-sided flight chamber. The natural sounds of the males of two species (Anopheles coluzzii and A. gambiae) and related synthetic sounds were played at different sound levels to individual free-flying A. coluzzii females. The mosquitoes’ responses were investigated by analysing changes in three-dimensional-tracked flight trajectories and wing-beat frequencies. The results show that (1) females do respond to the sound of swarming males, (2) a qualitative difference between female and male behaviour, (3) a quantitative effect of the sound stimulus of conspecific males, and (4) verification of previous results suggesting the importance of the first harmonic of their wing beats in mosquito acoustic communication.
Evaluation of a passive super-resolution beamforming technique for B-mode imaging
Authors: Agarwal Anil , Oelze Michael
Published: April 2019

Improving spatial resolution of ultrasonic scanners would allow improved imaging performance. A lateral resolution is limited by diffraction and the width of the beam used to interrogate the medium. Techniques for improving the lateral resolution beyond the diffraction limit have utilized dilute concentrations of microbubbles (MBs) to localize MB locations. These approaches enable the mapping of microvasculature but do not allow improvements in general B-mode imaging. Null Subtraction Imaging (NSI) is a passive nonlinear image processing scheme that constructs images from the nulls in the beam pattern of an array rather than the main lobe. In NSI, envelopes reconstructed with different apodizations are combined to form an image with an improved apparent lateral resolution. NSI is computationally efficient compared to adaptive beamforming approaches and does not need MBs. Experiments have demonstrated improvements in a resolution of over 100 times compared to conventional delay-and-sum beamforming with no apodization. Engineering trade-offs associated with combining different apodization functions, angular steering, and interpolation were assessed using the NSI technique. The utilization of the NSI for specific imaging tasks was also evaluated. The results of the study suggest that NSI could provide improved performance for the detection of small microcalcifications, which has application in detecting and identifying malignant cancers.
On a recovery of hoarseness by reflecting the amplified voice
Authors: Kim Myungsook , Bae Myungjin
Published: April 2019

If you make a loud voice and lecture with a high voice tone, you usually get a hoarse voice. The voice is generated by ejecting air pressure from the lungs through the folder of the vocal cords to create a tonal tone and resonance in the vocal tract. In this paper, we propose a new loudspeaker amplification tone that induces a hoarse voice when loudly voiced for a long time. In the proposed method, when the hoarseness was eliminated, the average sound pressure level was recovered to +5.2 dB and the spectrum in the high frequency range was improved by the average magnitude level of +12.6 dB. It is confirmed that the clarity of vocalization is more than usual in the measurement of vocal clarity.
Loudness growth as a function of presentation method: Comparison of normal hearing children with children using cochlear implants
Authors: Tak Shubha , Yathiraj Asha
Published: April 2019

The loudness of signals is altered in listening devices used by individuals with hearing loss, where soft sounds are made loud and loud sounds made soft. It is speculated that loudness growth would be affected in those using such listening devices. The study aimed to compare the effect of order of intensity presentation on loudness growth in typically developing children and children using monaural cochlear implants. Loudness growth of 3 warble-tones and 3 vowels were examined in 20 typically developing children and 17 children using cochlear implants. The intensity of the stimuli was varied randomly and sequentially. The children rated the loudness of the stimuli on a six-point rating-scale. Only 10 of the 17 children using cochlear implants gave valid loudness growth responses. These 10 children demonstrated no significant difference between the random and the sequential presentation for most of the stimuli. In general, the typically developing children exhibited a significant difference for the extremes in the loudness-growth scale (very soft and very loud). Loudness growth was similar across the methods and participant groups. Thus, a large number of children using cochlear implants are unable to give reliable loudness-growth responses. Those who have a loudness growth perform similar to the typically developing children.
Measuring the transmission coefficient of a steel plate using an angular spectrum approach
Authors: Spratt Kyle S. , Treweek Benjamin C. , Lee Kevin M. , Haberman Michael R. , Hamilton Mark F.
Published: April 2019

Ultrasonic measurements were performed on a thin steel plate submerged in water in order to obtain the plane-wave transmission coefficient as a function of angle and frequency. An angular spectrum approach was utilized wherein the acoustic field parallel to the plate was scanned with sufficient spatial accuracy to obtain a frequency-wavenumber description of the transmitted field, representing an expansion of the field into time-harmonic plane waves propagating within a range of angles. Isotropy of the plate material and symmetry of the measurement configuration allowed for a vast reduction of the number of scan points required in order to obtain the transmitted angular spectrum. Once the transmitted acoustic data is acquired, the specific method of windowing the data in space and time can have a drastic effect on the resulting angular spectrum. With sufficient care, a broadband estimation of the transmission coefficient with a high angular resolution is obtained. Finally, inverse methods were utilized in order to estimate the thickness and material properties of the plate using the measured transmission coefficient data. [Work supported by ONR.]
Generating ultrasonic acoustic holograms with circular arrays
Authors: Johnson Paul T.
Published: April 2019

Acoustic holograms are formed by interfering multiple sonic sources of identical frequency and differing phase. By using ultrasonic transducers, three-dimensional printed arrays, and an iterative approximation algorithm, it is possible to computer generate holographic arrays at 40 kHz in different configurations. By using circular arrays, I am able to explore vortex generation in an ultrasonic with a cost-effective desktop setup. These holograms can be measured and plotted using another transceiver. I also am able to make predictions about how to best optimize the designs for a circular array. This research opens up questions to be explored with even more powerful setups.
A comparative study of the dynamics of laser and acoustically generated bubbles in viscoelastic media
Authors: Sukovich Jonathan R. , Wilson Chad , Hall Timothy L. , Mancia Lauren , Rodriguez Mauro , Johnsen Eric , Xu Zhen
Published: April 2019

Here, we present results from experiments comparing the first-cycle growth and collapse dynamics of acoustically and laser-nucleated single bubbles in water and agarose gels of varying stiffness. Experiments were carried out in a custom-built spherical vessel which allowed both acoustically and laser-nucleated bubbles to be generated at its center. Bubbles were nucleated in water and agarose gels with stiffnesses ranging from 1.13 kPa to 570 kPa. Acoustically nucleated bubbles were generated using pulses delivered from 1 MHz transducer elements mounted in the vessel with pulse durations of <2 acoustic cycles. Laser-nucleated bubbles were generated using a pulsed Nd:YAG laser focused to the center of the vessel through an embedded window. Bubble dynamics were measured via optical imaging. The maximum radii of generated bubbles decreased with the increasing material stiffness for bubbles nucleated by both mechanisms. The growths and collapses of the bubbles occurred symmetrically (in time) about the maximum radius in water but not in gels, where the duration of growth decreased more rapidly than collapse as gel stiffness increased. Nucleation-mechanism-dependent differences in the growth-collapse asymmetry were observed which indicated that the growth duration of the laser-nucleated bubbles was longer than the acoustically nucleated bubbles in water and high water-content gels.
A cross-linguistic comparison on the use of acoustic cues for ambiguity resolution
Authors: Baek Hyunah
Published: April 2019

In producing structurally ambiguous sentences, speakers often rely on prosodic acoustic cues (duration, pitch, and intensity) to enhance communication. This study compared speakers of two languages in their use of these cues for ambiguity resolution. Ten English and 10 Korean speakers completed a production task in their native language. Stimulus sentences included a relative clause which could modify either the first or the second noun (e.g., the boss of the clerk who was dishonest). The participants produced each sentence twice, being directed each time to convey one or the other of the two possible meanings. English speakers used higher pitch and greater intensity on a word when it was being modified, but their use of durational cues was less consistent. Korean speakers, in contrast, consistently used lengthening on phrase-final word and longer pauses at the major constituent break, but their use of pitch and intensity was not consistent. These results suggest that to resolve parallel structural ambiguities, English speakers use pitch and intensity cues while Korean speakers use durational cues. I argue that this difference relates to the prosodic systems of each language, with English using pitch accents associated with words and Korean using boundary tones associated with accentual phrases.
Quantity, quality, both or neither? Vowel contrasts in Hakha Chin monophthongs
Authors: Haley Rebecca , Lotven Samson A. , Wamsley James , Berkson Kelly
Published: April 2019

Hakha Chin—a Tibeto-Burman language spoken in Chin State in western Myanmar—is reported to have phonemic length distinctions in its monophthongs (Melnik, 1997; Peterson, 2003; Maddieson, 2004) (e.g., [ii] vs. [i], [aa] vs. [a]). These pairs are also sometimes represented with tense/lax vowels (e.g., [i] vs. [ɪ], [a] vs. [ə]) (Peterson, 2017). Indeed, the results of a perception study conducted by Mortenson and Van Bik (2002) found variable response patterns in different dialect groups. Listeners from Hakha, the city after which the language is named, relied heavily on spectral cues related to quality to distinguish between long and short vowels, while listeners from the town of Thanthlang relied mainly on durational cues to perform the same task. In the current study, we present the first instrumental acoustic analysis of Hakha Chin vowel quality in order to aid in elucidating the nature of the contrast. Data from three college-aged native speakers (two male) suggest that neither duration nor quality play key roles in distinguishing between the so-called long and short vowels of Hakha Chin. Rather, as originally suggested by Maddieson (2004), the length associated with long vowels is mainly realized through lengthening of sonorant codas.
Nasal consonants block /o/ fronting in white and Lumbee speakers from Robeson County, North Carolina
Authors: Bissell Marie
Published: April 2019

This study examines /o/ fronting in white and Lumbee speakers in a tri-ethnic contact situation in Robeson County, North Carolina. Previously, Thomas (1989) observed that following nasal consonants may be blocking /o/ fronting in Wilmington, North Carolina. The present study examines this hypothesis in more depth in nearby Robeson County. Nine speakers were selected from the Sociolinguistic Archive and Analysis Project (Kendall, 2010). Nucleus and glide measurements were taken for each speaker's /o/ tokens, pre-lateral /o/ tokens, and pre-nasal /o/ tokens. Values were then Lobanov-normalized. Acoustic analysis of individuals speakers' vowel spaces suggests that when /o/ fronts, pre-nasal /o/ remains back along with pre-lateral /o/. While white speakers' pre-nasal /o/ patterns closely with their pre-lateral /o/, Lumbee speakers' pre-nasal /o/ tends to glide in a different direction in what could be considered a three-way allophonic split in the /o/ vowel class. The results of this study indicate that both following lateral consonants and following nasal consonants block /o/ fronting, though the phonological mechanism underlying pre-nasal /o/ backing is in need of further investigation.
Acoustic, non-invasive measurement of velopharyngeal aperture using a high frequency tone
Authors: McGowan Kevin B. , Johnson Michael T. , Combs Aleah D. , Soleymanpour Mohammad
Published: April 2019

Many researchers need access to the real time articulatory state of the velopharyngeal port to investigate the timing and extent of nasal gestures alongside the acoustic consequences of those gestures. While numerous methods exist for the investigation of nasalization (e.g., airflow, velotrace, and nasometer), these methods tend to be invasive, expensive, or to muffle the acoustic speech signal in pursuit of nasal articulatory data. We describe an inexpensive method and procedure for the investigation of nasal gestures using low frequency ultrasound. This system injects a 20 kHz tracer tone into a nostril using inexpensive components and/or three-dimensional printed parts. This signal can then be collected along with the speech signal using microphones typical in speech research. We will compare the results of this system to those of a state of the art airflow collection system and compare cross-participant reliability of both methods.
A non-primary cue in spontaneous imitation of English voiceless stops
Authors: Kwon Harim , Guo Yuting
Published: April 2019

When speaker-listeners are exposed to an exaggerated primary cue, they spontaneously imitate the enhanced cue; e.g., English speakers imitate extended VOTs of voiceless stops (e.g., Nielsen, 2011). Kwon (2015) claims that speaker-listeners enhance the primary cue for the relevant contrast when exposed to an enhanced non-primary cue, showing that Seoul Korean speakers imitated aspirated stops with an enhanced non-primary cue (stop VOT) by exaggerating the primary cue for phonological aspiration in the language (post-stop f0). However, VOT in Seoul Korean, despite being a non-primary cue, may enjoy a special status, since it is required to maintain the full three-way laryngeal contrast in the language. This study examines how the non-primary cue enhancement is imitated when the cue is not necessary for the relevant contrast. Native speakers of American English heard and spontaneously imitated English /t/ with either extended VOT (the primary cue for English voicing contrast) or raised post-/t/ f0 (a non-primary cue). Participants' own productions of English /t/ and /d/ before and after the exposure were compared. Preliminary findings suggest that the participants produced /t/ with longer VOT and higher post-stop f0 after hearing the stimuli with either manipulation but to a lesser degree after the f0-raised stimuli than the VOT-extended stimuli. The role of a non-primary cue in spontaneous imitation will be discussed.
Where the skies are not Cl/aʊ/dy all day: A pilot study of /aʊ/ production of speakers in rural Kansas
Authors: Champagne Matthew J.
Published: April 2019

This study examines cross-generational /aʊ/ production in rural, female speakers from Dickinson County, Kansas. Acoustic analysis of nuclei and glides were BARK normalized for cross-speaker, cross-generational comparison. This study finds older and younger speakers show similar nucleus advancement and glide direction.
Kyoo, what an odd-sounding word! Acoustic analyses of a Cajun interjection
Authors: Vidrine Lauren V. , Shport Irina A.
Published: April 2019

The interjection kyoo is used in English and French spoken by Cajun heritage speakers in Louisiana to express surprise. Cajun and non-Cajun speakers alike comment that kyoo sounds “weird,” as if it has some non-English characteristics. These perceptions may stem from Cajun French influence on Cajun English. Specifically, nasalized vowels and unaspirated stops are reported to occur in this dialect, more frequently in older than younger speakers. This case study investigated kyoo productions in two groups of Cajun English speakers to determine whether the word conformed to French-influenced sound patterns. Acoustic analyses showed that despite speaker auditory perceptions, the kyoo vowel was not nasalized as compared to other English words with oral and nasal codas. The spectral quality of this vowel was most similar to /ɔ/. Furthermore, voice onset time of the initial /k/ was not consistent with that of unaspirated stops. These results suggest the perception of anomalous sounds in this interjection may not be attributed to the acoustic characteristics indicative of French influence. Alternative explanations may include relatively long vowel duration due to speakers’ enthusiasm to perform Cajunness, palatalization of the initial stop followed by the open-mid back vowel, or simply non-standard nature of kyoo stereotyped by speakers.
The relationship between duration and spectral position in white southern US speech
Authors: Forrest Jon
Published: April 2019

Previous research on regional differences in vowel quality and duration found that white Southern speakers make less of a distinction between high and mid tense-lax vowel pairs in both quality and duration than speakers from other regions (Kendall et al., 2014). However, the effect of duration on vowel quality in Southern speech has not been explored to the same degree. This study examines duration, vowel quality (in F1-F2 space), and their relationship. Data come from 80 h of self-recorded and interview speech from 17 white Southern natives with varying degrees of the Southern Vowel Shift (SVS). Measurements for F1 and F2 were extracted at vowel nucleus (25% duration) for the /e/-/ɛ/ and /i/-/ɪ/ pairs both implicated in the SVS. Formants were Lobanov-normalized and both duration and vowel quality were examined with mixed-effects linear regression. Results show that most speakers maintain a durational distinction between tense-lax pairs, but the effect of duration on vowel quality varies greatly from speaker to speaker. Those speakers who exhibit higher degrees of SVS shift show individual slopes for duration in the opposite direction than less-Southern counterparts. First, these results demonstrate that controlling for individual differences in duration is important for properly analyzing Southern speech corpora. Second, they suggest that duration, vowel quality, and their relationship all play a role in regional distinction.
Application of simulated annealing particle swarm optimization in underwater acoustic positioning optimization
Authors: Li JiangQiao , Hui Juan , Huangpu Li , Bu Xianzhong
Published: April 2019

In the calculation of underwater acoustic positioning, the errors of element position measurement, time delay measurement, attitude accuracy and sound velocity measurement will lead to the calculation errors of final positioning solution. The optimization method of solution is also one of the key technologies of location solution. The traditional statistical methods of solution mostly use arithmetic average optimization method and Newton iteration method. In this paper, the particle swarm optimization method based on simulated annealing is used to improve the estimation accuracy of location solution. The effectiveness of this method is verified by computer simulation and comparative analysis. First, the spherical intersection method of synchronous positioning and the hyperbolic intersection method of asynchronous positioning are introduced in this paper. Then, the method of measuring time delay and filtering signal is introduced. Finally, another factor affecting positioning accuracy is discussed. The method of solving non-linear equation is discussed. By comparing the root mean square error of three methods under different signal-to-noise ratios, the signal-to-noise ratio is obtained. The accuracy of the three algorithms is almost the same when compared with each other, but at low SNR, the simulated annealing particle swarm optimization (SA-PSO) algorithm can calculate more accurate positioning solutions.
Rehearsal initiates systems memory consolidation, sleep makes it last
Authors: Himmer L. , Schönauer M. , Heib D. P. J. , Schabus M. , Gais S.
Published: April 2019

Rehearsal shifts mnemonic processing from the hippocampus to the posterior parietal cortex, sleep stabilizes the transition.
The short-chain fatty acid propionate increases glucagon and FABP4 production, impairing insulin action in mice and humans
Authors: Tirosh Amir , Calay Ediz S. , Tuncman Gurol , Claiborn Kathryn C. , Inouye Karen E. , Eguchi Kosei , Alcala Michael , Rathaus Moran , Hollander Kenneth S. , Ron Idit , Livne Rinat , Heianza Yoriko , Qi Lu , Shai Iris , Garg Rajesh , Hotamisligil Gökhan S.
Published: April 2019

Propionate activates the insulin counter-regulatory hormonal response in mice, resulting in insulin resistance and weight gain.
A decade of
Science Translational Medicine
Authors: Edelman Elazer R. , FitzGerald Garret A.
Published: April 2019

Science Translational Medicine
’s co-Chief Scientific Advisors discuss challenges and opportunities for the next decade of translational research.
Diversity of Contact-Dependent Growth Inhibition Systems of Pseudomonas aeruginosa
Authors: Allen Jonathan P. , Hauser Alan R.
Published: April 2019

Contact-dependent growth inhibition (CDI) systems are used in bacterial competition to hinder the growth of neighboring microbes. These systems utilize a two-partner secretion mechanism to display the CdiA exoprotein at the bacterial cell surface.
Draft Genome Sequence of a “
Candidatus
Phytoplasma asteris”-Related Strain (Aster Yellows, Subgroup 16SrI-B) from South Africa
Authors: Coetzee Beatrix , Douglas-Smit Nicoleen , Maree Hans J. , Burger Johan T. , Krüger Kerstin , Pietersen Gerhard
Published: April 2019

Here, we report the draft genome sequence of a phytoplasma discovered in grapevine. The genome size is 600,116 nucleotides (nt), with 597 predicted open reading frames.
Draft Genome Sequence of
Anaerosphaera
sp. Strain GS7-6-2, a Coccal Bacterium Isolated from a Biogas-Related Environment
Authors: Rettenmaier Regina , Neuhaus Klaus , Liebl Wolfgang , Zverlov Vladimir V.
Published: April 2019

Strain GS7-6-2 was isolated from a mesophilically operated biogas fermenter. The 16S rRNA gene sequence (93.27% identity to
Anaerosphaera aminiphila
WN036
T
) indicated that GS7-6-2 represents a putative novel species within the genus
Anaerosphaera
(family
Peptoniphilaceae
).
Draft Genome Sequence of a Medium- and Long-Chain
n
-Alkane-Degrading Bacterium, Tsukamurella tyrosinosolvens Strain PS2, with Two Genetic Systems for Alkane Degradation
Authors: Romanova Valeriya A. , Boulygina Eugenia A. , Siniagina Maria N. , Markelova Maria I. , Grigoryeva Tatiana V. , Laikov Alexander V.
Published: April 2019

Here, we report the genome sequence of
Tsukamurella tyrosinosolvens
strain PS2, which was isolated from hydrocarbon sludge of an organic synthesis factory. This strain was able to utilize a wide range of
n
-alkanes, from C
16
to C
35
, as sole carbon sources.
Complete Genome Sequences of Two Methicillin-Susceptible Staphylococcus aureus Clinical Strains Closely Related to Community-Associated Methicillin-Resistant S. aureus USA300
Authors: McClure Jo-Ann , Zhang Kunyan
Published: April 2019

Predominant community-associated methicillin-resistant
Staphylococcus aureus
strain USA300 is believed to have originated from an ancestral methicillin-susceptible strain, although the details of that evolution remain unknown. To help understand the emergence of this highly successful strain, we sequenced the genomes of two methicillin-susceptible
Staphylococcus aureus
clinical strains that are very closely related to USA300.
Repeatability of choroidal thickness measurements with Spectralis OCT images
Authors: Lau Jason K , Cheung Sin Wan , Collins Michael J , Cho Pauline
Published: April 2019

Objective

To investigate the repeatability of choroidal thickness measurements determined from enhanced depth imaging optical coherence tomography (EDI-OCT) images of eyes after wearing single-vision spectacles (SV) and orthokeratology (ortho-k) lenses.

Methods and analysis

Two EDI-OCT images of 40 children (SV: 20, ortho-k: 20) taken at a single visit were analysed twice. Subjects in the ortho-k group had been wearing ortho-k for 1–4 weeks. The choroidal thickness was determined from each image using a graph theory-based software and, where appropriate, manual correction of choroidal boundaries was undertaken by an experienced examiner.

Results

The mean (±SD) choroidal thickness was 227.3±42.2 µm for the SV subjects and 251.1±54.4 µm for the ortho-k subjects. The interimage differences in choroidal thickness were −0.99±3.54 and −1.14±5.03 µm for the SV and ortho-k subjects, respectively, and the limits of agreement were +5.96 to −7.93 and +8.72 to −11.00 µm, respectively.

Conclusion

The coefficients of repeatability of choroidal thickness measurements from two EDI-OCT images taken at a single visit were 7.08 µm (SV) and 10.06 µm (ortho-k), suggesting that a change in choroidal thickness of less than 10 µm may not indicate a real change resulting from ortho-k lens wear.
Spatial and genetic structure of the lodgepole × jack pine hybrid zone
Authors: Burns Ian , James Patrick M.A. , Coltman David W. , Cullingham Catherine I.
Published: April 2019

In north-central Alberta, lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia) and jack pine (Pinus banksiana Lamb.) form a mosaic hybrid zone, the spatial extent of which remains poorly defined. We sought to refine the genetic and geographic distribution of this hybrid zone in western North America to provide information important in predicting future risk of mountain pine beetle (Dendroctonus ponderosae Hopkins) outbreaks. We used 29 single nucleotide polymorphism (SNP) markers to discriminate lodgepole pine, jack pine, and their hybrids. We compared and contrasted spatial patterns of hybridization in northern and southern forest zones based on the colonization history of the two species. We found that patterns of introgression were more similar between the zones than expected by chance, but there were significant differences between these regions at specific loci. Using logistic regression, we created a robust predictive model to distinguish among lodgepole pine, jack pine, and their hybrids using a combination of geographic and environmental predictors. Using model selection based on Akaike information criterion, we found that location, elevation, and moisture are important predictors for species class. Quantification of the genetic differences between these two regions, combined with an accurate model for predicting the spatial distribution of lodgepole pine, jack pine, and their hybrids, provides essential information for continued effective management of forest resources.
Terahertz multi-band unidirectional reflectionless phenomenon in a MIM plasmonic waveguide system based on near-field coupling
Authors: Dai Tianyi , Zhao Fei , Zhang Cong , Jin Xing Ri , Zhang Ying Qiao , An Chengshou , Lee Young Pak
Published: April 2019

Dual-band unidirectional reflectionlessness is investigated in a system consisting of three stub resonators side-coupled to a metal-insulator-metal plasmonic waveguide based on near-field coupling in terahertz domain. Reflectivities of [Formula: see text] and [Formula: see text], respectively, at two exceptional points 4.11[Formula: see text]THz and 4.695[Formula: see text]THz are obtained for forward (backward) direction. More than that multi-band unidirectional reflectionlessness is demonstrated based on multi-stub resonators side-coupled to an MIM plasmonic waveguide.
Questioning quantum
Authors: Edwards Chris
Published: April 2019

Researchers hunt for ways to keep quantum computing honest.