bluuebunny/crossref_metadata_2025 huggingface dataset:
Prominence and tone in the Koasati nominal system
Authors: Gordon Matthew K. , Martin Jack
Published: November 2019

This paper presents results of an acoustic study of tone and prominence in nouns in Koasati, an endangered Muskogean language spoken in Louisiana and Texas. Certain nouns in Koasati are lexically marked for tone whereas, in most nouns, the first syllable is impressionistically most prominent (Gordon et al. 2015). In the present study, a list of Koasati nouns, comprising both words with and words without lexical tone, was recorded from six speakers in order to explore the phonetic realization of lexical tone and default word-level prominence. Target words, which ranged from two to six syllables in length, were embedded in a carrier phrase and repeated twice by each speaker. Duration, intensity, and several F0 measurements (mean, maximum, time of maximum, minimum, time of minimum) were logged for segments in the target words. Results indicate that the lexical tone is a LH bitonal sequence, which phonetically varies in its timing and scaling as a function of multiple factors including syllable type, following consonant, and speaker. The default prominence on the first syllable is associated with increased intensity and higher F0 (but not greater duration) and may be interpreted as either word-level stress or a phrase-level intonation effect. [Work supported by NSF.]
A simplification analysis of Andalusian aspirated stop clusters
Authors: Gylfadottir Duna
Published: November 2019

Weakening or “aspiration” of syllable-final /s/ is a widespread phenomenon in Spanish. When /s/ precedes a voiceless stop in varieties with /s/-aspiration, the result is normally a pre-aspirated stop [ht]. Some speakers in southern Spain now realize /s/ + stop (sC) clusters as post-aspirated stops, particularly in Western Andalusian Spanish (WAS) [Ruch and Harrington, J. Phonics 45(1), 12 (2014)]. Previous studies have analyzed this change as a timing realignment [Parrell, J. Phonics 40(1), 37 (2012)] or articulatory overlap [Torreira, JIPA 42(1), 49 (2012)]. The current study is the first to investigate sC clusters in naturalistic data. The data consist of 34 sociolinguistic interviews with WAS speakers. Preliminary results based on 10 speakers indicate a negative correlation between closure duration and VOT, and lower overall duration of post-aspirated clusters. Affrication of /ht/ to [ts] occurred at a rate of 7%, and deletion of the vowel in 4% of /ht/ tokens in vowel-initial words (e.g., [tha] for está), a phenomenon not reported in laboratory speech. We argue that low-level gestural realignment cannot account for the naturalistic variability in sC clusters, and argue for an account involving simplification to a single post-aspirated stop.
An acoustic view of the local Thai “Lae” reading and singing
Authors: Roengpitya Rungpat -.
Published: November 2019

This paper explores the acoustic characteristics of the local Thai “Lae” reading, as opposed to the singing one. The so-called “Lae /læ̀æ/” with the contents based on the local Thai culture has been the traditional Thai singing for centuries and has been enculturated only within the families of professional vocalists. In this paper, an acoustic study was conducted. Two professional Thai vocalists (one female and one male) were asked to read aloud and sing two Lae songs: the gac song (n = 236 syllables) and the song of the Mahasawat Canal (n = 272 syllables). There were a total of 2032 tokens (508 syllables X 2 speakers X 2 types). All the tokens were digitally recorded in a sound-proof room and acoustically analyzed in the Praat program. The results revealed that, in singing, the vowel duration and the final sonorants (if any) were two-three times longer; the vowels and diphthongs were lower (with higher F1); and the F0 levels for Thai tones were higher than the reading counterparts. Additionally, in vocalization, both female and male vocalists inserted extra syllables and glottalization while singing. It is hoped that this acoustic study will help glocalize and preserve the local Thai Lae singing.
An acoustic study of Iu-Mien tones with a special focus on the role of laryngealization in low tone differentiation
Authors: Thurgood Ela
Published: November 2019

The interaction of fundamental frequency (f0) and phonation types has been analyzed both in tonal languages in which phonation varies with tone [e.g., Jingpho (Maddieson and Ladefoged, 1985), Green Mong (Andruski and Ratliff, 2000), Jalapa Mazatec (Garellek and Keating, 2011), White Hmong (Esposito 2012)] and in tonal languages in which phonation is not contrastive. Patterns in the distribution of a non-contrastive phonation over tones have also been studied, for example in Mandarin (Keating and Esposito, 2007; Yu, 2010) and Cantonese (Yu, 2010). Previously unnoticed, however, is a phenomenon in which the same phonation type differentiates between two tones exclusively on the basis of differences not in its presence but in its distribution over the duration of the vowel. Here we explore an apparent case of this, investigating how f0 and laryngealization interact in Iu-Mien low tones and how this interaction is manifested across the vowel. The results show that low tones correlate with non-modal phonation. What is more, the study also shows that the distribution of laryngealization across the vowel length separates the low rise tone from the low rise-fall tone despite their pitch contours having been run together. This finding points to the development of contrastive phonation in Iu-Mien.
Improved array weighting for short nested arrays
Authors: Edelmann Geoffrey F. , Nordenvad Magnus L.
Published: November 2019

Often linear acoustic arrays are comprised of shorter nested subcomponent arrays cut for higher frequencies. This reduces costs and complexity by trading-off performance, specifically in resolution, SNR, and grating lobes. Typically each sub-aperture is processed individually, and the results incoherently combined over a frequency bandwidth of interest. Here several methods are shown superior to conventional bearing time records on measured at-sea data. Only methods that can be implemented in real-time and on low size, weight, and power systems are considered. Min and product array processing across the sub-apertures results are shown to have advantages, even though the nulls and grating lobes are not optimally coordinated. Finally, convex optimization methods are used to create array weights, over the entire irregularly spaced array. Stability is enforced via a regularization criteria added to the objective function. [Work Supported by ONR and the Royal Swedish Navy.]
Deployment of static underwater acoustic recorders in high tidal flow environments
Authors: Lepper Paul A. , LLoyd Steven , Benjamins Steven , Wilson Ben
Published: November 2019

The growth of interest in the development of harnessing tidal energy has also led to the requirement of assessment of underwaters sound fields in these environments. The radiated acoustic signatures of underwater systems in these environments is of significant interest. The measurements of the sound field in tidal flow areas however offer a number of major challenges. In a high flow environment, a static hydrophone would often suffer from significant flow noise. This parasitic noise is not real in the environment but a result of water column particle interaction with the hydrophone surface and has the capability of severely limiting the systems dynamic range for assessment of the true acoustic environment. Drifting system, moving at the speed of the water flow minimise this by reducing fluid particle to sensor interactions however are constrained by both temporal and spatial variations during the drifting limiting the ability to continuously monitor a system. Flow shield technology (sonar domes) have however been used extensively of the reverse problem of high-quality sound reception from a moving platform essentially suffering from the same problem. Work is presented on the use flow shield concept for a proto-type seabed mounted static recorder deployed in a high flow environment.
Experimental progress of noise measurements in reverberation tanks
Authors: Tang Rui , Li Qi , Zhang Yiming , Yu Xinyue
Published: November 2019

The methods and means for measuring the radiation characteristics of underwater sound sources have been developed under the conditions of reverberant tanks. From the perspective of experimental research, this paper introduces the methods of measuring the radiated sound power of steady-state sound sources and transient sound sources in reverberation tanks. The experimental subjects include the typical transducer under steady-state excitation, the cylindrical shell under steady-state excitation, the transient CW pulse sound signal and the underwater transient spark sound. The measurement principles, experimental system and measurement accuracy involved in each experiment are also listed. The experimental results show that the reverberation tank is an effective experimental device for measuring the acoustic characteristics of underwater sound sources, which has the advantages of simple experimental conditions, high measurement efficiency and strong tolerance for different types of sound sources.
Measuring the modal shapes of elastic targets using modulated radiation pressure
Authors: Abawi Ahmad T. , Kirsteins Ivars P. , Marston Philip L. , Daniel Timothy D.
Published: November 2019

In earlier work [T. Daniel et al., JASA 140, 3123 (2016)], we had shown experimentally that the resonance modes of elastic targets in water could be excited using modulated radiation pressure (MRP) generated by focused ultrasound to create detectable sound emissions. A potential advantage of the MRP approach is that the narrow ultrasound beam permits the generation of point-like forces on the target’s surface with surgical precision. In addition to exciting target modes with this technique, we show that by physically scanning the surface of the target with the point-like force generated by MRP, the mode shape of the target itself can be determined. The mode shapes are determined from the variations of the amplitude and phase of the radiated sound or the target’s surface velocity obtained using a laser vibrometer as a function of force locations. Theory will be developed, and results will be presented from experiments conducted in a tank at Washington State University. In these experiments, the mode shapes of small plates, cylinders, and UXOs were measured with MRP using hydrophone and laser vibrometer measurements and compared against those computed using finite element models.
Automatic detection and classification of fish calls in the Northern Gulf of Mexico using energy detectors and a convolutional neural network
Authors: Waddell Emily , Frasier Kaitlin E. , Hildebrand John , Širović Ana
Published: November 2019

Passive acoustic monitoring (PAM) is a relatively low-cost way to collect long-term datasets of animal occurrence, which is particularly effective when the animals are not constantly present. However, these long datasets can require substantial effort for manual analysis; therefore, automatic methods are a more effective way to conduct these analyses and extract calls of interest. In this study, acoustic recordings from the northern Gulf of Mexico, about 60 km north of the 2010 Deepwater Horizon oil spill location, collected between July 2010 and May 2017 were analyzed to determine if fish call abundance and diversity has changed after the oil spill. An energy detector was created to extract seven likely fish calls found in these data and a neural network was subsequently applied to classify the detections into different call categories. Daily, monthly, and yearly patterns in calls were investigated and a hypothesis was tested that there was an increase in call abundance and diversity over time, indicating recovery of fish populations since the oil spill. Such long-term studies demonstrate that PAM can be used as a population assessment tool for fisheries management.
Near-surface underwater noise generated by internal solitary waves in the South China Sea
Authors: Reeder D. Benjamin , Yang Yiing Jang , Ramp Steven R. , Jan Sen , Chang Ming-Huei
Published: November 2019

Underwater noise measurements were made over the steep continental slope east of Dongsha Atoll in the South China Sea during a field experiment from 23 May to 25 June, 2019. A single hydrophone was mounted at a depth of 20 m on a mooring deployed at 300 m water depth; temperature/pressure sensors and current meters were also deployed to monitor the water column temperature and velocity structure. Anticipated sources of underwater noise included ship traffic, wind waves and associated near-surface bubbles. Unique to this deep water environment are currents generated by the world’s largest observed internal solitary waves (ISWs) which generate noise associated with flow and bubbles subducted to depths in excess of 30 m. The observed noise variability primarily consisted of tidal- and subtidal-scale fluctuations, superimposed upon which were short timescale fluctuations generated by the ISWs. The noise levels observed during typical ISW passage exhibited a non-linear relationship with frequency, increasing by 5–10 dB at mid-frequencies (>1 kHz) and by 10–20 dB at low frequencies (<1 kHz).
Characterization of sound induced by bubbles released from nozzles
Authors: Zhang Likun , Fan Xudong , Lu Zhiqu
Published: November 2019

In an oil spill event, the leaked crude oil creates underwater sound through bubble oscillations and fluid jets. In this laboratory study, sound induced by bubbles in two types of oil leakage were simulated: a few bubbles and constant flow bubbles. We investigated sound emitted by bubbles released from nozzles, aiming to obtain the characteristics of the oil leakage from the recorded sound signals. For the few bubble case, the dependences of bubble size and frequency on the nozzle diameter were measured. A relation between the average size of bubble and acoustic frequency with the nozzle diameter was used to explain the measurements. In the case of constant flow bubbles, different flow rate was tested. The relation of acoustic energy with the flow rate was obtained from the experimental data. Bubble size distribution was obtained from the spectrum of recorded sound signals. The physical modeling of the bubble sound will be presented and discussed. [Funded by the Gulf Research Program of the National Academy of Sciences.]
Measurement of acoustic backscattering from rocky outcrops in Monterey Bay
Authors: Gruber Jen , Olson Derek R.
Published: November 2019

Acoustic scattering is an interaction between acoustic waves and inhomogeneities (interface or volume) which results in acoustic energy being dispersed in all directions. Scattering strength, a measure of the incoherent scattered energy, depends on grazing angle, frequency, bottom roughness, and/or sediment type and can be a source of false alarms for target detection systems. Understanding acoustic backscatter relationships of the sea floor allows for remote sensing applications, as well as target detection performance, in these areas. Acoustic backscatter from sand and mud bottoms has been studied extensively, but only six rocky bottom studies have been performed to date, motivating our study of high frequency acoustic scattering from rocky environments. For this project, acoustic data were collected and analyzed to measure the acoustic backscattering strength of rocky seafloors as a function of grazing angle, bottom roughness, and frequency in Monterey Bay, CA. High-frequency acoustic surveys with two narrowband split-beam echosounders, 200 kHz and 420 kHz, were conducted. Backscatter measurements were compared to existing bathymetric and geologic surveys from California State University, Monterey Bay and the California Geologic Survey to qualitatively compare backscattering strength to roughness features and geology.
Measurements of high-frequency acoustic scattering from sea ice over one season in the Chukchi Sea
Authors: Lyons Anthony P. , Deemer Gregory
Published: November 2019

Understanding recent and rapid changes in Arctic sea ice calls for extensive and continuous observations of the ice cover. In-situ stations are spatially limited and satellite remote sensing techniques miss key variables of internal sea-ice structure. Utilizing a dataset obtained with 38, 70, and 200 kHz upward-looking transducers in the northeast Chukchi Sea, we take a first look at how acoustic scattering changes in response to environmental forcing. A complete annual cycle of narrow band scattering returns from the winter of 2017–2018 are investigated with comparisons to the overlying sea ice cover. The initial effort in this research is constrained to the stable growth phase of sea ice in winter through the early melt onset the following spring. Individual, minimally deformed ice floes are identified and tracked when located over the deployment sites. Additionally, atmospheric conditions relevant to changes in the internal properties of sea ice are cross-compared to scattering returns. Results from this preliminary analysis will guide pending Arctic fieldwork and the future development of inverse methods for acoustic remote sensing of sea ice.
Estimation and validation of sediment properties by normal-incidence echosounder
Authors: Shearer Lucas , Gunderson Aaron , Isakson Marcia J.
Published: November 2019

Broad implementation of normal-incidence echo sounding has generated a need for sediment characterization models. These models may utilize the magnitude, phase, and/or envelope shape of reflected acoustic waveforms to infer physical, geoacoustic, and engineering properties of ocean sediment. Normal-incidence echo soundings enable the remote survey of vast underwater areas at a fraction of the cost of ground truth sampling methods, i.e., cores and grabs. In collaboration with the Dauphin Island Sea Lab, acoustic data was collected in the Petit Bois Pass off of the Alabama coast. The magnitude, pulse width, and skew ratio of the matched filter output were measured and quantified as bottom loss, full-width at half-max, and the ratio of half-width at half-max, respectively. Bottom loss measurements were used to determine the index of impedance which, through the application of empirically based regression equations, was then used to calculate sound speed ratio, density, mean grain size, and porosity of the sediment along the survey track. The estimated values of sediment properties are generally in agreement with those measured in the laboratory by ground truth survey. [Work supported by the Office of Naval Research, Ocean Acoustics.]
Brain-wide pulsatility mapping with gated ultrasound localization microscopy in vivo
Authors: Bourquin Chloé , Porée Jonathan , Lesage Frédéric , Provost Jean
Published: November 2019

Cardiovascular diseases are associated with cognitive impairment. Aging arteries increased stiffness leads to an increased pulsatility in downstream vessels and brain structural damage. Hence, brain-wide pulsatility maps could yield a powerful biomarker for neurodegenerative diseases. Ultrasound Localization Microscopy (ULM) can probe the rodent brain smallest vessels, but is currently limited to averaged velocities over multiple cardiac cycles. The objective here was to map the pulsatility using ULM in a rat brain in vivo using a cardiac-gated approach. Rat brains were imaged following craniotomy with a Vantage system (L22-14, Verasonics, WA). ECG-gated frames were acquired in groups of 400 (1000 fps) during 8 min following a microbubble injection. More than 20 × 106 bubbles were detected and tracked to map local velocities. Significantly distinct velocities could be measured during systole and diastole in the entire rat brain. Pulsatility indexes from 0.15 in cortical branches to 0.30 in the anterior cerebral artery could be measured, with an increase in blood velocities of 8% to 15% during systole compared to diastole. To our knowledge, this study reports for the first time the mapping of small vessels pulsatility in the entire rodent brain. [We acknowledge the support of IVADO, TransMedTech and Apogée/CFREF.]
The parabolic approximation in therapeutic ultrasound
Authors: Soneson Joshua
Published: November 2019

An ideal mathematical model is both accurate and tractable. It must predict the physics of interest and produce solutions in an efficient manner. In the field of therapeutic ultrasound, where simulations of finite-amplitude sound beams are an important adjunct to bench testing, the parabolic approximation of the wave equation often strikes a balance between these two requirements. In this presentation the common approaches to computing ultrasound fields are introduced and a family of high-order parabolic models is derived and analyzed. This analysis provides the framework for addressing a challenge often encountered in medical ultrasound modeling: controlling spurious effects associated with steep gradients in the source boundary condition. The accuracy of the resulting high-order propagation models is assessed by comparing against solutions of the full wave equation and the degree to which these models capture the salient characteristics of ultrasound beams is analyzed. This approach brings to therapeutic ultrasound a “wide-angle” parabolic model with improved diffraction modeling capability and no penalty to computational efficiency.
Connecting high-power jet noise characteristics with human annoyance
Authors: Downing Micah , James Michael M. , Calton Matt , Salton Alexandria R. , Gee Kent L. , Vaughn Aaron , Wakefield Gregory H.
Published: November 2019

DoD has funded the development of advanced modeling tools for community noise exposures and for exploring noise reduction techniques. However, inadequate understanding of high-power jet noise sources and the effects of radiated noise on people are both limiting factors in mitigating community noise exposure. In the meantime, both ground personnel and community noise exposure lead to annoyance and disturbance, costly noise mitigation, and burdensome restrictions on operations. Therefore, DoD is exploring acoustical metrics that may better correlate jet noise exposure to human response. More broadly, DoD and the jet noise research community desire an increased understanding of jet noise source characterization to best focus on promising strategies for reducing jet noise impacts. This research project seeks to address these two needs by increasing the understanding of tactical jet noise sources and by correlating their physical noise features, such as noise source distribution, directivity, and shock content, with human response related to annoyance, disturbance, and the perception of crackle. This presentation will provide an overview of the project’s objectives. [Work Supported by AF SBIR Program.]
Spectral comparisons between ground runup and flyover operations of a high-performance military aircraft
Authors: Ward Jacob A. , Gee Kent L. , Downing Micah
Published: November 2019

Prior work has shown differences between ground runup and flyover noise levels for military aircraft [B. O. Reichman et al., AIAA Paper 2018-3614]. This presentation describes a continuation of that effort to better understand spectral differences as a function of propagation distance, angle, and engine power. Acoustical measurements of a high-performance military jet aircraft made during both ground runup and flyover operations are described. The ground runup and flyover spectra show substantial differences in both shape and levels. In particular, more high-frequency energy is seen in the forward direction in the flyover data, which is believed to be from nonlinear propagation. This analysis examines in greater detail the increased nonlinearity in the forward direction, which is important to improved modeling of the noise from these aircraft. [Work supported by AFCEC.]
Underwater characterisation of acoustic modes supported by structured and unstructured elastic plates
Authors: Starkey Timothy , Graham Thomas , Hibbins Alastair , Sambles J Roy
Published: November 2019

Surface waves are supported by unstructured, or appropriately structured, elastic materials. Unstructured plates typically support a number of Surface Acoustic Waves (SAWs) that propagate at the boundary of the elastic materials—these can be bound or leaky. Whilst plates with appropriate structure can support bound Acoustic Surface Waves (ASWs) which propagate in the fluid at the fluid/solid boundary. In this talk, we present the underwater acoustic characterisation of both SAWs and ASWs supported by unstructured and structured aluminium plates. First, we measure the dispersion of the symmetric and antisymmetric leaky Lamb modes of an unstructured aluminium-alloy plate using a broadband ultrasound technique. Beaming of acoustic power over a narrow frequency band is observed. This is attributed to the first order symmetric leaky Lamb mode, which exhibits Negative Group Velocity (NGV) in a small region of its dispersion. Finally, we show that a perforated elastic plate supports a bound ASW. We characterize the dispersion of the supported modes using time-domain measurements of the surface wave pressure recorded as a function of position, and observe acoustic beaming of surface energy over a narrow frequency band. All results show close agreement with numerical models.
Study of wave propagation through porous lattices with buckling instabilities in an aqueous environment
Authors: Konarski Stephanie G. , Naify Christina J. , Rohde Charles
Published: November 2019

Elastic lattices with cylindrical air-filled voids may undergo significant topology changes when deformed due to the buckling instabilities of the thin elastic ligaments between voids. Such phononic crystals are of interest to, for example, achieve auxetic behavior and create tunable stop bands that vary as a function of the deformation. Most studies reported in the literature by others focus on lattices made of soft elastomers, and the resulting nonlinear deformation or elastic wave propagation due to low-frequency vibrations in air. The current research focuses on transitioning these previously studied concepts on buckling lattices to an aqueous environment. Initial investigations presented here are for 3-D printed lattices comprised of rigid plastic and deformed by leveraging shape memory effects that result in softening and hardening of materials under heating and cooling, respectively. The use of rigid plastic addresses inherent difficulties that arise with soft elastomers, including high loss, fabrication at scales of interest, and appropriate frequency range for wave propagation. The present work focuses on numerical simulations and experimental measurements of wave propagation through finite, plastic lattices with air-filled voids in water. [Work Supported by the Office of Naval Research.]
Cortical dynamics of word-in-noise recognition
Authors: Choi Inyong , Kim Subong , Schwalje Adam , Woo Jihwan
Published: November 2019

Understanding speech in background noise is a crucial function for communication. Despite the growing body of research on this topic, it is still unexplained how the neural processes for spoken-word recognition are affected by the acoustic degradation of target speech. To address this question, we utilized high-density EEG simultaneously measured during a word identification task with varying levels of background noise. We hypothesize that, if background noise degrades speech sound, listeners will exhibit less immediate processing of speech information, waiting to access lexical entries until most of the word has been heard. We showed that, as we hypothesized, in the more difficult lower-SNR condition, cortical evoked response to target word is weaker in the auditory cortex while the induced and evoked responses from the inferior frontal cortex are delayed but greater, which may imply delayed lexical processing. This study elucidates what neural mechanisms underly effortful speech understanding in challenging acoustic conditions.
Pitch perception conveyed by cochlear implant and tactile stimulation
Authors: Bissmeyer Susan R. , Hwang Juri , Goldsworthy Raymond L.
Published: November 2019

The healthy auditory system encodes acoustic frequency as a tonotopic and synchronous neural response. Cochlear implants (CIs) excite tonotopic organization through place of stimulation and excite a synchronous neural response through stimulation timing, but typically limited to amplitude modulations less than 300 Hz. The results from two experiments will be presented. The first experiment uses CI stimulation to examine the contributions of place and rate of stimulation to pitch perception. Frequency discrimination thresholds were measured in adult CI users for fundamental frequencies ranging from 100 to 1600 Hz. Stimulation was controlled to probe pitch sensitivity as conveyed by place, rate, and covaried place and rate of stimulation. Subjects received a significant low-frequency benefit from combined stimulation, which diminished above 400 Hz as stimulation rate no longer provided a salient sense of pitch. The second experiment considers how well tactile stimulation can be used to augment pitch perception in CIs. Tactile discrimination thresholds were measured for 55 and 110 Hz. Preliminary results will be presented for the second experiment designed to test how well CI users can combine pitch cues provided by stimulation rate and by tactile stimulation.
Can word frequency norms based on small spoken corpora compete with norms based on popular written corpora?
Authors: Abrahamyan Hayk
Published: November 2019

Current word frequency norms used in speech research are based on written corpora. Recently, Brysbaert and New (2009) presented newer frequency counts based on larger corpus of film and television subtitles, on the idea that these would more closely approximate actual spoken frequencies. Although Brysbaert and New (2009) showed that their frequencies significantly better predict visual reaction time data, they still used corpora with text that was originally written and perhaps heavily edited. In general, most speech researchers prefer using norms from a larger written corpora as norms from spoken corpora are often based on smaller number of tokens (i.e., less then one million). However, many studies use only a small subset of words, frequencies for which may not benefit from a large corpus. Furthermore, many studies dichotomize words into high- and low-frequency groups, thus rendering fine distinctions between frequencies of words computed using a large corpus potentially less useful. The first goal of the current project is to compute word frequency norms using only material from spoken corpora. The second goal is to compare predictions of performance from speech processing experiments of norms from spoken corpora with norms based on popular written corpora. Our preliminary results indicate that for the vast majority of familiar words that are likely to be used in small research studies, any frequency norm even from a small spoken corpus predicts equivalent amount of variance in lexical decision data.
Perceptual grouping modulates level-increment discrimination in stop consonant noise bursts
Authors: Espinoza-Varas Blas , Guo Shaoxuan
Published: November 2019

Does perceptual grouping modulate the ability to discriminate level increments (ΔL) in stop-consonant noise bursts? In consonant-vowel-consonant (CvC) words comprising an ≈80-dB vowel (v), a pre-vocalic (Cv) and a post-vocalic (vC) stop-consonant noise burst (≈ 60-dB SPL), we measured ΔL thresholds for bursts in isolation or in CvC context. Each interval of 2I-2AFC tasks presented a CvC word (e.g., /pæk/ /pæk/), and participants had to discern ΔL in Cv or vC. Relying on linguistic labels, the auditory events are perceived as two auditory objects (Cv-v-vC and Cv-v-vC) that group bursts and vowels together, hampering attention to ΔL. To discern ΔL in Cv or vC, events must be reorganized into three auditory objects: the to-be-attended pre-vocalic (Cv-Cv) or post-vocalic burst pair (vC-vC), and the to-be-ignored vowel pair (v-v). Relative to bursts in isolation, bursts in context produced higher thresholds (context effect), which depended on the time separation between the bursts and the vowel: lower for the object apart from (post-vocalic) than for the object adjoining (pre-vocalic) the vowel (temporal-position effect). In addition to being robust and persistent, these effects are relatively general, evincing in tasks with one or two observation intervals, with or without variability in the temporal position of ΔL.
F0 as a secondary cue for consonant aspiration in Mandarin Chinese
Authors: Guo Yuting , Kwon Harim
Published: November 2019

Previous studies on stop production in Mandarin Chinese have reported conflicting results on consonant-induced F0 perturbation (e.g., Xu and Xu, 2003, Luo, 2018). This study investigates whether Mandarin listeners use F0 information as a cue for consonant aspiration when F0 perturbation is limited and inconsistent in production. Specifically, we examine Mandarin listeners' perception of phonological /th/-/t/ contrast, focusing on how voice onset time (VOT) and post-stop F0 influence their perceptual judgments. Mandarin listeners heard /tu/∼/thu/ syllables with the initial stop co-varying in its VOT and post-stop F0 in the four lexical tone contexts, and were asked to identify the syllable they heard. Results demonstrate Mandarin listeners relied mainly on VOT for /th/-/t/ contrast, but the effect of VOT interacted with post-stop F0 and lexical tone. F0 did not influence the perceptual judgments when VOT was unambiguous. However, when VOT was ambiguous, Mandarin listeners identified the stops with high F0 as /th/, and those with low F0 as /t/. Lexical tones mediated this effect: Tones with low pitch onset elicited more unaspirated responses than those with high pitch onset. These findings suggest that Mandarin listeners use F0 as a secondary cue for consonant aspiration, but to different extent in different lexical tones.
Container ship source level and directionality measurements
Authors: Gassmann Martin , Wiggins Sean M. , Kindberg Lee B. , Hildebrand John
Published: November 2019

Underwater radiated noise from container ships was measured opportunistically from multiple spatial aspects to estimate directionality and signature source levels. Transiting ships were tracked via the Automatic Identification System in a shipping lane while acoustic pressure was measured at the ships’ keel and beam aspects. Port and starboard beam aspects were 15, 30, and 45 deg in compliance with ship noise measurements standards [ANSI/ASA S12.64 (2009) and ISO 17208-1 (2016)]. Source levels were derived with a spherical propagation (surface-affected) or a modified Lloyd’s mirror model to account for interference from surface reflections (surface-corrected). Ship source depths were estimated from spectral differences between measurements at different beam aspects. In addition, recordings were made at a ∼10 deg starboard aspect and utilized to measure and compare signatures of MAERSK G-class container ships before and after the ships were equipped with new propellers as part of MAERSK’s $100+ million Radical Retrofit Program.
International standards for the measurement of underwater noise from vessels: Numerical modelling in support of a shallow water standard
Authors: Humphrey Victor F. , Cen Yin , Robinson Stephen P. , Wang Lian
Published: November 2019

ANSI and ISO have issued standards for the measurement of the radiated noise level of surface vessels in deep water. In addition, a draft standard for the conversion of such measurements into a monopole source level, as required for environmental noise models, is at an advanced stage. However, many operators and investigators are constrained to making measurements in shallow water where both sea-surface and seabed effects are important. In order to study the influence of these effects a numerical study has been performed using both an image source model and OASES, with very good agreement. The goal of this work has been to understand the variability of the correction factor required to convert measurements of received pressure, at short range, into the equivalent source level in such an environment. These calculations have included the effects of reflection at both the sea-surface and an attenuating seabed. The influences of the water depth, seabed type, distance of closest approach, and number and location of the hydrophones have been investigated. The results show how the correction factor varies and indicate the extent to which simplified approximations can be used for the correction factor.
“Who”: Perception of talker properties
Authors: Bent Tessa
Published: November 2019

Spoken language simultaneously provides listeners with linguistic content and information about the person speaking. Listeners can identify specific individuals from auditory-only speech signals. Furthermore, listeners can identify a range of physical and socio-cultural talker characteristics (indexical characteristics) with above chance accuracy. Listeners are sensitive to relatively stable aspects of a talker's identity, such as their age, height, gender, race/ethnicity, sexual orientation, region of origin, native, and language status. Talkers also transmit more transitory information (e.g., current health status or emotional state). The mental representations that listeners build for individual talkers and speaker groups interact with the processing of linguistic information, such that the same physical acoustic signal can be interpreted in different ways depending on the talker's perceived indexical characteristics. In this talk, I will focus on how these mental models can allow for more efficient and accurate processing of speech signals. For example, listeners are more accurate at identifying words from familiar than unfamiliar talkers. Likewise, listeners more accurately understand speech from non-native speakers after a period of exposure. Research on the “who” of speech perception demonstrates the need for considering the interaction between talker characteristics and listener knowledge when making decisions about speech privacy.
EarthScope-Oceans: An array of floating MERMAID instruments for earthquake seismology
Authors: Simons Frederik J. , Simon Joel D. , Hello Yann , Nolet Guust , Obayashi Masayuki , Chen Yongshun J.
Published: November 2019

Mapping the Earth's uncharted interior through global seismic tomography is dependent on increasing the number of seismic stations in the oceans. We have developed a low-cost, autonomously floating hydrophone to capture earthquake signals suitable for the study of the interior of the Earth and the tectonically and magmatically active underwater realm, while it maintains its potential to be an environmental monitoring device. MERMAID is a freely drifting diver that combines (1) a hydrophone, (2) GPS, (3) an on-board digitizing and processing unit that uses wavelet detection and discrimination algorithms, and (4) an iridium unit for near real-time data transfer with two-way communication. The instrument, 50 kg in air, submersible to 3000 m water depth, with a projected lifetime of up to 5 years, is commercially available from OSEAN SAS. Some 60 units will have been deployed in the Pacific Ocean by the Fall of 2019. With up to 7 kg of sensor payload, additional configurable sensors today include a Sea-Bird SBE 41 CTD, and, in the future, a suite of other instruments with utility in bioacoustics, environmental monitoring, meteorology, bathymetric determination, and chemical and physical oceanography. We report on the performance of our instruments as regards teleseismic event recovery, and on the development of a new method for extracting high-resolution travel times from the first ~1500 seismograms reported live from the Pacific Ocean.
Characterization of HIFU fields inside of a tissue-mimicking HIFU phantom
Authors: Howard Sam , Zanelli Claudio I.
Published: November 2019

The use of a tissue-mimicking, scatterer-free polyacrylamide gel phantom for HIFU has been previously described [1]. This transparent material combines with a marker with an absorption of 0.6 dB/cm MHz which turns opaque when the temperature exceeds 65 °C. After a brief review of the material properties and their validation, we discuss typical uses of the phantom as part of QA and protocol development and discuss comparisons between phantom and free-field measurements in water at high intensities. Comparisons are also made to new investigations where in situ pressures have been measured by embedding a fiber-optic probe into a sample of a phantom material. [1] S. Howard, J. Yuen, P. Wegner, and C. Zanelli, “Characterization and FEA simulation for a HIFU phantom material,” in IEEE Ultrasonics Symposium (2003), pp. 1270–1273.
Shear wave attenuation measurement of tissue-mimicking materials using a two-point frequency shift method
Authors: Kijanka Piotr , Urban Matthew W.
Published: November 2019

Shear wave elastography (SWE) is a method used in several clinical applications for assessment of soft tissue viscoelastic properties. SWE uses an acoustic radiation force (ARF) to produce laterally propagating shear waves to obtain the wave velocity. Here, we present a two-point shear wave attenuation coefficient measurement method without using a rheological model. The technique uses information related to the magnitude spectrum frequency shift of shear waves measured at only two lateral locations. We examined how the distance from the start of the ARF push and the distance between the two locations affected the attenuation coefficient estimates. We tested this method on digital phantom data created using local interaction simulation approach in viscoelastic media and on data acquired from phantom and ex vivo liver experiments. We compared the results from the two-point method with other two techniques used for assessing shear wave attenuation: the frequency-shift-based (FS) method and attenuation measuring ultrasound shearwave elastography. In comparison with the FS method, our technique does not assume that the shape parameter of the Gamma function is constant over a lateral distance. Tests conducted showed that the proposed method is feasible to provide robust attenuation estimates based on two measurement points in tissue-mimicking materials and ex vivo liver tissue.
Numerical modeling of collinear mixing of compressional and shear waves in nonlinear elastic media using the iterative nonlinear contrast source method
Authors: Selvam Sundaraelangovan , Volker Arno , van Neer Paul L. , de Jong Nico , Verweij Martin D.
Published: November 2019

In nondestructive testing, nonlinear wave mixing could be used to obtain the nonlinearity parameters of an elastic medium and thereby get information about its state, e.g., aging and fatigue. To better understand the mixing mechanisms and optimize the design of measurement setups, a physics-oriented tool for the simulation of nonlinear elastic wave propagation would be valuable. In this presentation, we extend the iterative nonlinear contrast source method (INCS) to study the nonlinear mixing of two plane, collinear bulk waves (one compressional, one shear) in a homogeneous, isotropic, elastic medium with two independent coefficients of nonlinearity (βL and βT). The method successfully captured the resonant wave generated due to the mixing (one-way and two-way) of primary waves of different frequencies. The obtained results for the resonant wave were in good agreement with the results reported in the literature. In addition, the contrast source allowed the propagating and evanescent components of the scattered wave field to be studied in the wavenumber-frequency domain, which provides physical insight into the mixing process and explains the propagation direction of the scattered wave. Thus, the INCS method seems to be a useful tool to investigate and predict wave mixing in nonlinear elastic media.
Noise source modifications to enhance performance of an acoustic modulation system
Authors: Hall Melissa A.
Published: November 2019

The ability to simulate extreme flight environments of aerospace structures, such as high-intensity thermal acoustic loading, is achieved through the use of a progressive wave tube facility. This valve modulation system, used to create the random acoustic wave, behaves like an electromagnetically driven spring-mass system that uses electro-pneumatic, vibrating-vane air valves as the noise source. Each valve requires an electrical input and reaction with a magnetic field to generate the force necessary to overcome the spring stiffness of the outer portion of the valve. This force, driven by a current carrying wire, opens and closes the modulation slots, creating airflow pressure pulses necessary to generate higher sound pressure levels. Several physical characteristics of the noise source can be modified to generate a higher force on the spring section of the valve. This work documents the increase in the overall sound pressure level output of the noise source by varying the cross-sectional area and gage size of the current carrying wire, documenting performance of materials which strengthen the magnetic field, and by comparing the frequency about which the narrow band drive signal was centered. Based on the results of these comparisons, an optimal combination of physical characteristics will be discussed.
Co-speech laughter in a conversational speech task
Authors: Perkins Booker Nynaeve , LaRoque Cheyenne M. , Danner Samantha G. , Krivokapic Jelena , Byrd Dani
Published: November 2019

Laughter plays a role in the natural flow of conversation. This study examines four dyads participating in a semi-structured collaborative conversational speech task to assess the effects of participant role—listener versus speaker—and the location of laughter within a speech turn on laughter distribution and duration. We hypothesize that speakers’ laughter will be more constrained than listeners’ due to its limitation to speech turn boundaries and its accommodation of a speaker’s ongoing speech planning requirements. Additionally, based on prior findings on acoustic phrase-final lengthening in speech prosody, we expect that laughter at the end of a speech turn will be longer than turn-initial or -medial laughter. Our results demonstrate substantial individual variability, with a majority of participants having longer laughter duration as listeners than as speakers, in part, we propose, due to laughter’s use as a form of backchanneling. Participants also demonstrate longer durations of turn-initial laughter than turn-final or turn-medial laughter. This unexpected result may be due to overlapping speech and laughter that is often seen at the end of speech turns. Our results suggest that the patterning of laughter with respect to speech turns may help structure interactive speech discourse. [Work supported by NIH.]
Voice actors simulating small vocal tracts: A study using 3-D ultrasound
Authors: Feehan Colette
Published: November 2019

Voice actors are an interesting population for linguistic study because their professional field requires them to perform complex vocal tract manipulations in order to consistently and believably convey many different character types. Previous investigations have looked at how voice actors manipulate laryngeal setting and voice quality, to portray specific types of characters in animation (Teshigawara and Murano, 2004; Starr, 2015), but investigations of articulatory manipulations employed by voice actors are rare. This study uses 3-D ultrasound and acoustic analyses to compare the different kinds of articulatory and phonatory strategies that different actors use in order to approximate a smaller vocal tract and achieve a similar ‘childlike’ percept. Preliminary analysis shows that one amateur actor relies on manipulation of articulatory setting by implementing hyoid bone raising, gesture fronting, and tongue grooving, whereas one professional actor relies more on manipulation of laryngeal structures and prosody. Despite these differences in approach, the two actors still achieve similar child-like percepts. This poster will compare strategies from two female and two male subjects as well as describe within-subject variation across each actor’s adult and imitated child voices.