bluuebunny/crossref_metadata_2025 huggingface dataset:
Complexity-entropy based approach for detection of fish choruses
Authors: Siddagangaiah Shashidhar
Published: October 2018

Increasing anthropogenic noise around the world ocean are affecting the marine ecology. Recently, acoustic indices (AI) were utilized to quantify the biophony in the marine soundscape. However, these AI’s employed in complex marine environment, dominated by several anthropogenic and geophonic sources are yet to be understood. In this study, we have introduced a method based on complexity-entropy (C-H) for detection of biophonic sounds originating from fish chorus. The fish chorus detection performance of C-H was compared with AI’s such as acoustic complexity index (ACI), acoustic diversity index (ADI), and bioacoustics index (BI). We have utilized the data collected at Changhua (A1) and Miaoli (N1). During the Spring of 2016 and 2017, the region N1 was exposed to continual shipping activities, due to which there was ~10 dB increase in the low frequency (5–500 Hz) noise levels. This enabled us to evaluate the fish chorus detection performance of various AI’s and C-H method, and the robustness in the presence and absence of shipping activities. The results presented in this study shows that, during the fish chorusing hours, the introduced entropy is positively correlated with Pearson’s correlation coefficient (Pcc) > 0.95 and complexity is anticorrelated with Pcc < -0.95. Therefore, the introduced C-H method has potential implication in efficient detection of fish chorus and overcome the limitations confronted by AI’s such as ACI, ADI, and BI.
Double-difference tracking of migrating Bowhead Whales using autonomous vector sensors in the Beaufort Sea
Authors: Tenorio-Hallé Ludovic , Thode Aaron , Conrad Alexander , Blackwell Susanna B. , Kim Katherine H.
Published: October 2018

Passive acoustic monitoring has become a standard method for detecting bowhead whale (Balaena mysticetus) activity in Arctic waters. Between 2007 and 2014, over 40 autonomous vector sensors, known as DASARs, were deployed in the Beaufort Sea during the bowhead whale migration season. Individual DASARs can estimate azimuth, allowing calls to be localized by triangulation using multiple DASARs. However, these bearings are subject to calibration biases, and individual sensors were not precisely time-synchronized, making relative time-of-arrival information unreliable for standard localization purposes. Double-difference methods have previously been applied in seismology to obtain high-precision relative positions of earthquakes by measuring changes in relative travel-times between multiple events over widely distributed seismic sensors. This same concept has also been used to track fin whales on a seafloor seismic network. Here, the double-difference method is applied to previously localized bowhead whale calls in order to improve their relative positions. The approach uses changes in both relative call travel-times and bearings, detected at multiple DASARs, to determine high-precision relative locations of these calls despite the presence of systemic timing and bearing errors in the measurements. The resulting positions may allow tracking of individual whales, which would provide insight into the function of these calls.
Estimating North Pacific Right Whale calling depths in the Bering Sea via modal dispersion
Authors: Wright Dana , Thode Aaron , Bonnel Julien , Thieury Margaux , Fagan Aileen , Verlinden Chris , Berchok Catherine L. , Crance Jessica
Published: October 2018

Calling depth distributions and ranges are estimated for two types of calls produced by critically endangered eastern North Pacific right whales (NPRW) in the Bering Sea, using passive acoustic data collected with bottom-mounted single-hydrophone recorders at the 50 m isobath. Nonlinear time resampling of 12 NPRW “upcalls” and 20 broadband “gunshots” typically isolated 3 to 4 individual mode arrivals below 200 Hz. Matched-mode processing (MMP) methods were then used to estimate range, depth, and propagation environment. When plotted as a function of range and frequency, MMP ambiguity surfaces reveal the existence of large sound speed gradients in the sediment, along with strongly downward-refracting sound speed profiles during certain summer/fall seasons. Refractive propagation effects from these profiles can induce dramatic changes in signal structure that required new developments in “warping” techniques. Gunshot sounds were generally produced at a few meters depth, while upcall depths clustered between 10 and 25 m, consistent with previously published bioacoustic tagging results from North Atlantic right whales. Current work is examining whether consistent differences exist in the calling depths of bowhead, humpback, and right whales, which could potentially provide a feature for species classification of ambiguous calls. [Work sponsored by NPRB.]
Multi-year measurements of the underwater noise field directionality in the shallow Beaufort Sea during open-water and drifting ice flow conditions
Authors: Thode Aaron , Blackwell Susanna B. , Kim Katherine H. , Conrad Alexander
Published: October 2018

Between 2007 and 2014, over 35 Directional Autonomous Seafloor Acoustic Recorders (DASARs) were deployed over a 280 km swath of the Beaufort Sea continental shelf (20–55 m depth) during the open-water season, in order to monitor the fall (westward) bowhead whale migration. DASARs have one omnidirectional pressure sensor and two orthogonal particle motion sensors, which permit instantaneous measurements of the azimuths of both transient signals and continuous noise between 20 and 500 Hz. The lack of significant shipping or industrial noise in this region provided a rare opportunity to directly measure the properties of wind-driven noise in expanding ice-free regions. Here, we map the azimuthal directionality of the diffuse Beaufort ambient noise field as a function of frequency and space across seven seasons. The dominant directionality of the diffuse ambient noise field varied strongly with frequency and was highly correlated with the received power spectral density. Certain directional features of the ambient noise field remained stable over seven deployment seasons, suggesting that judicious processing of the ambient noise soundscape could provide underwater navigational information in arctic waters. The influence of local drifting floes and sheets of ice on this directionality is also examined. [Work sponsored by ONR.]
Low frequency (20 kHz), patch-like ultrasound applicator for chronic wound treatment
Authors: Lewin Peter A. , Ngo Olivia , Niemann Evan , Gunasekaran Vivinya , Sankar Prabagar , Lafontant Alec , Nadkarni Sumati , DiMaria-Ghalili Rose Ann , Neidrauer Michael , Zubkov Leonid , Weingarten Michael , Margolis David
Published: October 2018

Chronic wounds, such as venous and diabetic ulcers, cost the U.S healthcare system alone, close to $25 billion annually. Hence, a reduction of healing time directly translates into savings of treatment related expenses. This work describes the implementation of patch-like, un-tethered and clinically viable therapeutic ultrasound applicator. The device uses well-defined non-cavitational and non-thermal levels of ultrasound energy; its peak acoustic output pressure amplitude was intentionally limited to 55 kPa, corresponding to a spatial peak temporal peak intensity of 100 mW/cm2. A small (n = 8) pilot study targeting diabetic ulcers treatment was performed and indicated that with its light weight (<20g), and circular (40 mm dia) disk shape architecture this applicator is suitable to be embedded in wound dressing. The average time to wound closure was 4.7 weeks for subjects treated with the active device, compared to 12 weeks for subjects treated with a sham applicator, suggesting that patients with diabetic ulcers may benefit from the proposed treatment. [Work supported by the NINR grant5R01NR015995. The contents of this presentation are solely the responsibility of the authors and do not necessarily represent the official views of the NIH.]
Creating uniform ultrasound fields in the brain without an array
Authors: Richards Luke A. , Cleveland Robin , Stride Eleanor P.
Published: October 2018

There has been a recent interest in using patient specific ultrasound lenses to correct for the phase aberration caused by the skull in focused transcranial ultrasound. Here, we apply acoustic lenses to the problem of creating a highly uniform field inside the skull, motivated by the requirements of targeted and ultrasound responsive nanodroplets being developed for the treatment of brain metastases. The phase and amplitude required for uniform sonication was determined from simulations of ultrasound propagation utilising CT data as a basis for the geometry of the patient’s skull. From these simulations, silicone lenses were produced, capable of introducing phase inhomogeneity in the incident ultrasound beam to compensate for the effects of transmission through the skull. Experimental measurements with an ex vivo skull showed that phase uniformity could be at least partially restored within the skull cavity. Methods for modulating the amplitude of incident ultrasound have also been investigated. Stereolithography was used to directly print in highly attenuating (15 dB/cm at 1 MHz) materials, allowing rapid production of customised and selective acoustic absorbers. A 3D printed transducer backing was also studied, able to suppress transducer output in certain regions, and provide up to 15 dB dynamic range across the surface of a planar ultrasound transducer.
Prediction of noise from an automotive turbocharger centrifugal compressor using three-dimensional computational fluid dynamics
Authors: Dehner Rick , Selamet Ahmet , Selamet Emel
Published: October 2018

The noise generated by centrifugal compressors for automotive turbochargers consists of narrow and broadband components. Narrowband noise occurs near integer multiples of the shaft rotational frequency, and the prevailing order is typically equal to the number of main impeller blades (impeller blade-pass frequency). However, for a centrifugal compressor without a ported shroud recirculating casing treatment, such as the current contemporary configuration, broadband noise is dominant, typically in the 4–12 kHz range. This study applies a three-dimensional computational fluid dynamics model to this compressor installed on a steady-flow turbocharger stand. As the compressor flow rate is reduced at constant rotational speed, broadband noise is elevated as a result of deterioration of the flow-field near the inducer (inlet) of the impeller, due primarily to flow separation from the suction surface of impeller blades. Detached eddy simulations provide reasonable agreement with the corresponding experimental measurements in terms of capturing performance, as well as acoustics, thereby shedding insight into this noise source mechanism associated with such flow separation.
An investigation of the interactions between impulsively started and steady supersonic jets
Authors: Natarajan Karthikeyan , P Suriyanarayanan , Venkatakrishnan Lakshmi , Sathiyavageeswaran Sankaran
Published: October 2018

The ignition of the solid rocket booster strap-on and the following IOP wave have a severe influence on the dynamic as well as the acoustic loads experienced by a launch vehicle during lift-off. The jet from the strap-on interacts with the core jet and its established flow over the jet blast deflector, influencing the acoustic field experienced by the launch vehicle. The existing literature provides very little understanding of such interactions. This work investigates the interaction between the jet from SRB and the core, by simulating them with an impulsively started supersonic jet in close proximity to another established jet. While the flow for the core nozzle was allowed directly from the settling chamber, a novel approach using a quick opening valve was used for initiating the flow through the strap-on nozzle. The evolution of a strong shock wave emanating from the strap-on nozzle and the ensuing vortex ring, their interaction with the core jet flow, etc., was captured using schlieren. The results document the fluid dynamic interactions such as the evolution of a strong shock wave emanating from the strap-on nozzle and the ensuing vortex ring, their interaction with the core jet flow, etc., using flow visualizations and acoustic measurements.
Flow and acoustics of an isothermal supersonic 2:1 rectangular jet with an adjacent surface
Authors: Gutmark Ephraim , Baier Florian , Karnam Aatresh
Published: October 2018

In integrated airframe/propulsion system configurations, additional noise sources can be created from the interactions between the jet flow and the adjacent airframe surfaces. Another situation of surfaces of close proximity occur during takeoff and landing when the ground is close enough to cause the jet-surface interference. The impact of a plate oriented parallel to the axis of a 2:1 rectangular supersonic jet (De = 20.65mm) at the minor axis side is studied. Plate offset (h) distances of h = 0, 1, 2, and 3 equivalent diameters from the nozzle lip to the surface are included. The impact of the plate is studied at nozzle pressure ratios (NPRs) of 2.5–4.5 when the design Mach number is 3.67, at a temperature ratio of TR = 1.1. Mean and turbulent flow field data are acquired using streamwise particle image velocimetry (PIV). Trends of shock cell spacing, potential core length, and shear layer development are analyzed. Near and far field data are taken and correlated with the flow field details. The offset from the nozzle is shown to vary flow and acoustic properties and impact screech tones.
Coherence analysis of the simulated sound field of a highly-heated laboratory-scale jet
Authors: Leete Kevin M. , Gee Kent L. , Liu Junhui , Wall Alan T. , Swift S. Hales
Published: October 2018

Large eddy simulations (LES) have successfully reproduced the flow and acoustic fields generated by laboratory-scale jets. However, laboratory-scale test conditions ordinarily do not match those of full-scale military aircraft. Recently, Liu et al. (AIAA 2016–2125) showed that accounting for a variable ratio of specific heats leads to increased accuracy in LES simulations of heated jets. As a step towards modeling operating parameters similar to military aircraft, they produced a simulation of a highly-heated jet with a temperature ratio of seven. This paper shows the levels in the field as well as the axial and azimuthal coherence trends of this simulated jet. Large axial coherence lengths are found in the direction of maximum radiation with decreased coherence towards the sideline. Azimuthally, coherence length scales are greatest in the region of maximum radiation and generally decrease with increasing frequency. Additionally, evidence is seen for multiple self-coherent and mutually-incoherent radiation lobes within the region of maximum radiation. [Work supported by USAFRL through ORISE.]
Updated evaluation of sonic boom noise metrics
Authors: Loubeau Alexandra , Wilson Sara R. , Rathsam Jonathan
Published: October 2018

There is no internationally agreed-upon standard noise metric that can be used to quantify sonic boom levels from overflight of supersonic aircraft. Several laboratory studies have investigated perception of sonic booms in outdoor environments, as well as in indoor environments, where transmission loss alters the spectral content and level of the sonic boom and additional factors such as secondary rattle noise and vibration affect perception. Each study has previously been evaluated separately for performance of noise metrics, and the results do not clearly indicate a preferred metric. Meta-analyses have also been performed to evaluate the performance of metrics across five of these studies. An additional sixth study of human response that incorporates rattle noise resulting from sonic booms at representative levels was recently conducted and has been added to the meta-analysis. The analysis considered thirteen metrics with three meta-analysis methodologies: individual subject ratings for indoor studies, mean ratings for indoor studies, and mean ratings for both indoor and outdoor studies. Considering both indoor and outdoor studies, this latest analysis confirmed previous results on the five metrics with highest correlation (r2) across studies: PL, BSEL, DSEL, ESEL, and ISBAP (Indoor Sonic Boom Annoyance Predictor).
Sea surface contribution to sound transmission loss: Numerical comparison between three-dimensional and cylindrical symmetry approximation solutions
Authors: Vecchiotti Andrea , Gasparini Luca , Ryan Teresa J. , Vignola Joseph F. , Turo Diego
Published: October 2018

The atmospheric sound propagation over the sea depends on several factors including but not limited to temperature, wind speed, relative humidity, and roughness of the surface. The objective of this study is to determine the contribution to sound transmission loss of the sea surface roughness. The governing equations are implemented for a three-dimensional domain using a finite element method solver. The sea surface is assumed to be perfectly reflective and its shape is pseudo-randomly generated by using the Pierson and Moskowitz model. In previous studies, the cylindrical symmetry approximation has been widely used to allow a fast computation of the equations. However, the implementation of a three-dimensional domain allows a more realistic scenario and is here used as a tool to quantify the deviation from the approximated solution. An appropriate correction factor to be used when applying the cylindrical symmetry approximation is determined.
On atmospheric humidity and acoustic ducts
Authors: Vignola Joseph F. , Turo Diego , Judge John , Ryan Teresa J.
Published: October 2018

The development of various propagation ducting phenomena (elevated or surface) has been studied extensively for electromagnetic and electro-optical wave propagation. The influence of changes in temperature, pressure, and humidity gradients on the strength and geometry of the duct in the electromagnetic propagation problem is well-documented, and there is substantial literature regarding the influence of temperature gradient on atmospheric acoustic propagation. Analytical results indicate that moisture gradients in warm air above a sea surface contribute meaningfully to the refraction of sound. This work uses numerical simulation to explore the atmospheric conditions that would support development of acoustic ducts or wave guide conditions during moderate range (<1 km) acoustic propagation. The aim of this overall effort is an improved numerical model of acoustic refraction and attenuation over moderate to long distances above a sea surface that accounts for sea state as well as boundary layer wind, temperature, and humidity profiles.
Changes in the minimum audible angle may be related to systematic distortions in sound localization and motion perception
Authors: Brimijoin W. Owen
Published: October 2018

Systematic distortions in our perception of acoustic space have been repeatedly documented in the literature. For example, listeners exhibit a characteristic overestimation of azimuth when they are asked to point a laser at a sound source while keeping their head and eyes fixated ahead of them. Motion perception also appears to be non-uniform as a function of azimuth, as demonstrated by the fact that listeners need roughly twice as much motion at the side than at the front to judge the two motions as equivalent. This talk will make the case for a common source of these two perceptual inconsistencies, namely, the change in minimum audible angle (MAA) as a function of azimuth. Classically speaking, the MAA is thought of as a threshold measure that increases at more eccentric angles because of a change in the availability of binaural cues. Regardless of the source, we argue here à la Fechner that azimuth overestimation and motion perception non-uniformity are suprathreshold consequences of the change in acuity. By treating, e.g., 20° of acoustic space at the side as equivalent to 10° at the front, a model of the perceptual topology of acoustic space can capture several previously reported findings in spatial hearing.
Effects of interaural delay, center frequency, and no more than ”slight” hearing loss on binaural processing: Behavioral data and quantitative analyses
Authors: Bernstein Leslie R. , Trahiotis Constantine
Published: October 2018

Recent neurophysiological studies concerning “hidden hearing loss” have motivated investigators to attempt to uncover behaviorally-measured auditory deficits that might exist in human listeners who would be categorized via standard audiometry as having normal hearing or, at most, “slight” hearing loss. We hypothesized that behavioral measures of binaural auditory performance could reveal the presence of deficits that may not be discoverable via standard audiometric testing or via measures of monaural processing. That hypothesis was based on the notion that monaural (perhaps, peripheral) deficits would be effectively multiplied via binaural interaction. Groups of listeners, all having no greater than “slight” hearing loss were tested. Binaural detection thresholds were elevated across a wide range of center frequencies for listeners whose absolute thresholds at 4 kHz exceed 7.5 dB HL. Quantitative predictions made via an interaural correlation-based model of binaural processing suggest that the elevated binaural detection thresholds observed for listeners having slightly elevated absolute thresholds stem solely from their having elevated levels of internal noise. They appear to stem neither from reduced sensitivity to signal-dependent changes in information derived from the stimuli as processed internally nor from increased noise along the listener’s putative internal delay line.
Does electrode placement affect the interaural-time-difference acuity in bilateral cochlear-implant listeners?
Authors: Stakhovskaya Olga A. , Bernstein Joshua G. , Noble Jack H. , Jensen Kenneth K. , Hoa Michael , Kim Hung J. , Goupell Matthew
Published: October 2018

Postlingually deafened bilateral cochlear-implant (CI) listeners can show limited interaural-time-difference (ITD) sensitivity, even when tested using highly controlled time-synchronized research processors. It is assumed that ITD discrimination requires interaural frequency-matched inputs. However, current bilateral CI programming procedures do not account for potential interaural place-of-stimulation mismatch. This study investigated the magnitude of interaural place-of-stimulation mismatch and its effects on ITD sensitivity in bilateral CI listeners. Ten bilateral CI listeners were tested on a two-interval left-right ITD discrimination task. Loudness balanced, 300-ms, 100 or 200 pulse-per-second, constant-amplitude, monopolar pulse trains were delivered to single-electrode pairs using time-synchronized research processors. ITD just noticeable differences (JNDs) were measured for five reference electrodes evenly distributed along the array in one ear, and for at least five comparison electrodes, generating ITD tuning curves. The interaural mismatch was estimated using both the ITD tuning curves and differences in the angular insertion depth from computed-tomography (CT) scans. Data showed that ITD tuning curves were relatively broad when compared to the amount of physical interaural place-of-stimulation mismatch from the CT scans. This suggests that most bilateral CI listeners do not experience appreciably reduced binaural sensitivity due to differences in electrode placement.
Effect of the resonance frequency on the work flow with adjusting the internal temperature of the stack in a standing-wave thermoacoustic-system
Authors: Sugimoto Mana , Sakamoto Shin-ichi , Kurata Yuya , Kawashima Yuto , Watanabe Yoshiaki
Published: October 2018

We discuss the stack which is the key device of the thermoacoustic system. We elucidate the stack mechanism to realize further energy conversion efficiency improvement. We propose installing a heater inside the stack. This heater adjusts the internal temperature of the stack and controls the heat flow in the stack. Controlling the heat flow in the stack can also affect the mutual conversion of the heat flow and the work flow. In this report, the effect of the resonance frequency with the standing-wave thermoacoustic-system and the internal temperature of the stack on the heat flow in the stack was experimentally investigated. The resonance frequency was changed with the total length of the system. As a result, the lower the frequency, the larger the amount of the work flow generated in the stack. This can be influenced by the increase and decrease of the dissipation with changing the resonance frequency. Also, at any resonance frequency, the amount of the work flow generation increased with controlling the heat flow in the stack. The heat flow can be controlled by adjusting the internal temperature of the stack at any resonance frequency.
Phase diagram of coupled thermoacoustic chaotic oscillators
Authors: Delage Rémi A. , Takayama Yusuke , Moeko Sato , Hyodo Hiroaki , Biwa Tetsushi
Published: October 2018

Linear analysis of thermoacoustic oscillations have been extensively made, but there is still a lack of knowledge on nonlinear phenomena such as synchronization and chaotic oscillations. Thermoacoustic chaotic oscillations have been reported in Taconis and combustion oscillators but these systems do not allow a well-controlled experiment because of the extreme temperature conditions. By making the system acoustically dissonant, we recently succeeded in generating thermoacoustic chaotic oscillations with modest temperatures. In this study, we present spatiotemporal evolution of thermoacoustic chaos from pressure measurements, and report an experimental bifurcation diagram when two thermoacoustic chaotic oscillators are dissipatively coupled to each other. The two-parameter bifurcation diagram is constructed by varying the frequency mismatch and the coupling strength. Complete chaos synchronization is observed in the region with a frequency mismatch of less than 1% of the uncoupled oscillator, with on-off intermittency phenomenon for low coupling strength. In other regions, synchronization between quasiperiodic oscillations and that between limit-cycle oscillations and oscillation death are observed as well as asynchronous states.
Evidence for a 3-component model of speech production with phonology-extrinsic timing
Authors: Turk Alice , Shattuck-Hufnagel Stefanie
Published: October 2018

This talk will present evidence supporting a model of speech production which includes phonology-extrinsic timing, and consists of 1) a Phonological Planning Component to plan the goals for an utterance, including the segmental and prosodic structure for an utterance and non-grammatical goals such as speaking quickly or in a particular style, 2) a Phonetic Planning Component to plan the quantitative details of the acoustic goals and how they will be achieved articulatorily, and 3) a Motor-Sensory Implementation Component to ensure that the goals are achieved on time. Supporting evidence from the literature includes findings of greater timing precision at movement endpoints compared to other parts of movements, suggesting the separate control of the timing of movement endpoints compared to other parts of movement. This evidence presents a challenge to models in which all parts of a movement trajectory are controlled by the same equation of motion, but is consistent with models in which 1) abstract, symbolic phonological representations map onto spatial and temporal characteristics of movement endpoints, 2) movements are planned to reach the endpoints on time, and 3) speakers give priority to the accurate implementation of the part(s) of movement most closely related to the phonological goals.
Coupling tonetics and perceptual attunement: The psychophysics of lexical tone contrast salience
Authors: Burnham Denis K. , Singh Leher
Published: October 2018

As with the coupling phonetics and psycholinguistics by such luminaries as Sereno and Jongman, we couple (a) discrepant cross-lab results in infant lexical tone perceptual attunement studies and (b) an adult cross-language lexical tone perception study. Three trajectories of lexical tone perception over infants’ first year have been found over labs, in which infants from differing language backgrounds have been tested with differing stimulus materials, viz., (i) Incremental (Singh’s lab—Singaporean Mandarin vs Singaporean English language background infants, Singaporean Mandarin tone contrasts; Tsao’s lab-Taiwanese and English language infants, Taiwanese Mandarin contrasts); (ii) Decremental (Burnham’s lab—Australian English but not for Cantonese or Mandarin language infants, Thai contrasts; Yeung/Werker’s lab—American English but not for Mandarin and Cantonese language infants, Cantonese contrasts); and (iii) U-shaped (Kager’s lab—Dutch infants, Mainland Mandarin contrasts). To investigate these discrepancies, we tested discrimination of Singaporean Mandarin, Beijing Mandarin, Hong Kong Cantonese, and Bangkok Thai tone contrasts by Singaporean Mandarin, Beijing Mandarin, Hong Kong Cantonese, Bangkok Thai, and Sydney Australian English listeners. Despite some discrepancies, this coupling revealed some congruences between psychophysical level of difficulty of tone contrasts within and between languages in the adult study, and the different developmental trajectories in the infant studies.
Investigating the representation of tonal alternations in context
Authors: Chien Yu-Fu , Yan Hanbo , Sereno Joan A.
Published: October 2018

Phonological alternations pose challenges to models of spoken word recognition in how surface information is mapped onto stored representations in the lexicon. In Mandarin, a full Tone3 (213) is reduced to an abridged tone (21) (half-third sandhi) when followed by Tone1, Tone2, or Tone4. In addition, Mandarin Tone3 is replaced by Tone2 when followed by another Tone3 (third-tone sandhi). Two experiments used auditory-auditory priming lexical decision to investigate the alternating representations of Tone3. In Experiment 1, targets consisted of disyllabic words with a half-third or full-third FIRST syllable. These targets were preceded by either a half-third prime, a full-third prime, or a control Tone1 prime. RT data showed facilitation effects for both half-third and full-third prime conditions, with no first syllable by prime type interaction. In Experiment 2, third-tone sandhi targets consisted of disyllabic words with a half-third or full-third SECOND syllable. These targets were preceded by either a half-third prime, a full-third prime, or a control Tone1 prime. The data also showed both half-third and full-third priming effects, without any second syllable by prime type interaction. The results suggest that Mandarin Tone3 is stored as half-third (21) and full-third (213) forms, with both of these tone3 phonological alternations activated.
Perception of voiceless nasals in Mizo and Angami
Authors: Gogoi Pamir , Wayland Ratree
Published: October 2018

This study is a perceptual analysis of place of articulation of voiceless nasals and their voiced counterparts in Mizo and Angami, two Tibeto-Burman languages spoken in North-East India. The voiceless nasals in Mizo and Angami differ in terms of their characteristics of voicing. In Mizo, there is a portion of voiced nasal murmur before the vowel starts, which has been compared to the voiceless nasals in Burmese (Bhaskararao & Ladefoged,1991). However, in Angami, the nasal murmur remains voiceless throughout (Bhaskararao & Ladefoged,1991; Blankenship et al.,1993). A previously performed acoustic analysis of cues for place of articulation in both the languages shows that the cues were more robust in the transition portion of the vowel following the voiceless nasal (Gogoi, 2018). The perception of voiceless nasals by native speakers have not yet been studied. However, existing literature on Burmese voiceless nasals have shown that there are sufficient acoustic cues in the voiced murmur portion of the voiceless nasals for discrimination of the place of articulation (Dantsuji,1986). This study investigates whether the perception results correspond to the acoustic analysis previously observed.
Characterizing the coordination of speech production and breathing
Authors: Kallay Jeffrey , Redford Melissa , Mayr Ulrich
Published: October 2018

A robust, positive correlation between inhalation depth and subsequent utterance length in read speech has been interpreted as an anticipatory effect. Since anticipatory posturing of the respiratory system during phrase preparation has important theoretical implications, the present study was designed to rigorously test the effect. Healthy college-aged participants learned by rote a passage with equal numbers of short and long sentences, which were randomized to create a zero (lag-1) autocorrelation sequence that controlled for priming effects. Rote learning was used to control for visual cues to utterance length. Multiple repetitions of the passage produced by six speakers were acoustically segmented into pause-speech intervals for preliminary analyses, with pause intervals coded for breath intake or no intake. Analyses on data that retained the experimental structure indicated a strong effect of preceding utterance length on the presence/absence of breath intake, but no effect of subsequent utterance length. Analyses of breath pause durations indicated only significant negative correlations with utterance length, and no relation between intake duration and utterance length. Together, the results suggest only an effect of physiological recovery on speech breathing under conditions that better approximate spontaneous production than in previous studies. [Work supported in part by NIH award number R01HD087452.]
Cue enhancement and effects in [l] and [n] identification in L2 English
Authors: Li Bin
Published: October 2018

[l] and [n] in English sharing certain articulatory characteristics are acoustically similar (Ladefoged 2003, Lass 1996), which has been reported to cause confusion in consonant recognition (Mermelstein 1977, Espy-Wilson 1992, Pruthi 2004), and adds significantly to the perceptual challenge that Chinese L2 learners of English are faced with (Li 2006). Young Cantonese speakers, for example, often get confused with the English contrast because /l/ and /n/ are considered in free variation and in the process of merging into one in contemporary Cantonese. Despite the articulatory and acoustic similarities, [l] and [n] differ in many ways such as consonantal duration and changes at the constriction release (Li, Zhang, Wayland 2012). This study modified temporal and spectral correlates of the two consonants at various positions in a word, so as to test if cue enhancement could affect L2 consonant perception. University students in Hong Kong were recruited to identify sounds of the contrasting pair in English. Their results suggest that lengthening the consonant and consonant-vowel transition may help the learners better identify the sounds.
The perception-production link in sibilant convergence
Authors: Long Yanyu
Published: October 2018

Many theories suggest a link between perception and production, but evidence for such a link is inconsistent. This study addresses this issue by looking at the relationship between perception of sibilants before [u] or [a] and production change when imitating words starting with a lower-frequency [s] before [u] or [a]. Sibilants were measured by center of gravity. The results at first showed no relationship between production change and perception. However, a closer look revealed that some participants converged to the stimuli while others did not. Mixed effect models showed that for people who converged, larger difference between the perception distribution and the stimuli corresponds to more convergence. This is consistent with the observation that people converged more in the [sa] words, since [s] before [a] has higher perception distribution, hence more distant from the stimuli. No difference was observed between the [u] and [a] contexts in terms of the coefficients of perception in predicting convergence. The results show that no matter what the phonetic context is, inputs are recoded in terms of their distance from the perception distribution before influencing production. With larger such distance, the chosen production targets are farer away from the baseline, resulting in more convergence.
Gender, the individual, and intelligibility
Authors: McCloy Daniel , Panfili Laura , John Cornelia , Winn Matthew , Wright Richard
Published: October 2018

In the clinic and in the laboratory, opinions differ on the relative intelligibility of the speech of women and men. However, the effect of gender alone has rarely been studied explicitly. Here we present a study of 30 talkers (15 male) and 32 listeners assessing intelligibility of a 180-sentence subset of the IEEE sentences presented in steady-state speech-shaped noise. Four signal-to-noise ratios (−4, −2, 0, + 2 dB SNR) were tested with 45 sentences each. Results showed substantial overlap between intelligibility scores for each gender. Although standard statistical approaches show a slight advantage for female talkers at all SNRs, post-hoc analyses indicated that the gender effect is an artifact driven by a few particularly unintelligible males. These results do not address intrinsic gender-related differences in speech intensity, or in the ability to overcome background noise by speaking clearly, but suggest that gender-related differences are negligible when those factors are controlled. More generally, even with a large sample of talkers, the high degree of talker-intrinsic variability in intelligibility can lead to conclusions that do not generalize to the population of interest, an issue that could affect comparisons rooted in gender, dialect, or other social factors.
Effect of distributional shape on learning a target sound
Authors: Sadlier-Brown Emily , Hudson Kam Carla L.
Published: October 2018

Vowel pronunciations (measured in Hz) form distributions that vary from normally distributed to quite skewed. Labov (2001) noted that vowels undergoing change tend to be skewed, while stable ones are not. We ask if the different distributions are causally related to change. We exposed participants (n = 238) to a positively skewed, negatively skewed, or normal distribution of pure tones varying in pitch (to mimic how vowels vary in quality). Participants were told they were listening to notes played by amateur musicians who’d been aiming for the same note. In each trial, participants listened to 20 tones then played the note they thought was the target. Output pitches were compared to the input. The question was whether learners would play a tone corresponding to the mean or the mode of the set or would instead “shift” the note. In the two conditions analyzed so far (normal and positively skewed), participants output pitches that were slightly higher than the mean of the input set, indicating shift in both conditions; however, the difference between conditions is not significant. There is also an effect of the final note in the set, evoking the well-established recency effect in memory. Analysis of the third condition is ongoing.
Bayesian association of multiple infrasound events using long-range propagation models
Authors: Millet Christophe , Bertin Michael , Mialle Pierrick
Published: October 2018

The International Monitoring System (IMS) is a worldwide network of monitoring stations that helps to verify compliance with the Comprehensive Nuclear Test-Ban Treaty by detecting events that might indicate violations of the treaty. The IMS uses a combination of four technologies: seismological, radionuclide, hydroacoustic, and infrasound. An important limitation of these technologies is related to the fact that the structure of the propagation medium is partially unknown. This is especially true for the infrasound technology, and indeed, a current trend is to undertake the impact of atmospheric variability on waveforms using computational models. Simulation-based predictions, however, are inherently limited by large uncertainties. Further, many thousands of detections are recorded per week and thus, the problem of calculating plausible waveforms for subsets of detections often leads to computational demands that exceed available resources. In this paper, we present a new powerful statistical model for analyzing and interpreting large-scale IMS data. The method is based on a parallel Markov chain Monte Carlo algorithm and full-wave modeling. The method can detect association when multiple, interacting events are present in the data. The posterior probability of no association can be estimated, thereby providing a way to reduce the false alarm rate in operational-like environments.
Blind equalization and automatic modulation classification of underwater acoustic signals
Authors: Marcoux Caitlyn N. , Chandna Bindu , Blair Ballard J.
Published: October 2018

It is useful to passively characterize the underwater acoustic communications environment for a variety of purposes, including interference avoidance and enforcement of restrictions protecting marine mammals. Automatically determining the modulation of a received waveform can permit sonar or communications operations within the same bandwidth with a minimum of collisions, and it can identify a particular system operating outside its permitted regime. The characterization system needs to both determine the modulation and an unknown, time-varying channel impulse response since the transmitter and receiver are not coordinating. In this work, we demonstrate the use of blind equalization along with Convolutional Neural Networks for automatic classification of underwater signals. Our current research focuses on classification of constant modulus signals and demonstrates an approximate 30 percent improvement in modulation classification, compared to approaches without equalization, and a significant reduction in the amount of data needed for training. We considered BPSK, QPSK, MSK, FSK and 8-PSK modulations using simplified synthetic channels simulated via MATLAB to demonstrate our results. Future work is aimed at demonstrating classification improvement using realistic channel models simulated via the Sonar Simulation Toolkit, real underwater channels gathered from data collects, and additional underwater acoustic signal types.
Optimal experimental design for machine learning using the Fisher information matrix
Authors: Neilsen Tracianne B. , Transtrum Mark K. , Van Komen David F. , Knobles David P.
Published: October 2018

Optimal experimental design (OED) refers to a class of methods for selecting new data collection conditions that minimize the statistical uncertainty in the inferred parameter values of a model. The Fisher information matrix (FIM) gives an estimate of the relative uncertainty in and correlation among the model parameters based on the local curvature of the cost function. FIM-based approaches to OED allow for rapid assessment of many different experimental conditions (e.g., input data type, parameterizations, etc.). In machine learning models, accurate parameter estimates are often not a priority (nor even desirable) as they have no direct physical meaning. Instead, one would like to minimize the uncertainty in the model predictions for several quantities of interest. FIM approaches to OED can be generalized to minimize statistical variance, not in parameters, but in predictions of the quantities of interest. This approach has been applied, for example, to systems biology models of biochemical reaction networks [Transtrum and Qiu, BMC Bioinformatics 13(1), 181 (2012)]. Preliminary application of the FIM to optimize experimental design for source localization in an uncertain ocean environment is a first step towards an efficient machine learning algorithm that produces results with the least uncertainty in the quantities of interest.
Reductions in underwater radiated noise from shipping during the 2017 Haro Strait vessel slowdown trial
Authors: MacGillivray Alexander O. , Li Zizheng
Published: October 2018

During 2017, the Vancouver Fraser Port Authority's Enhancing Cetacean Habitat and Observation (ECHO) program carried out a voluntary slowdown trial in Haro Strait (British Columbia) to investigate whether limiting vessel speeds to 11 knots would decrease noise in Southern Resident Killer Whale habitat. During the trial, JASCO collected source levels measurements on two underwater listening stations situated adjacent to the Haro Strait traffic lanes, while a third listening station in Georgia Strait measured noise from vessels outside the slowdown zone. Acoustic data from these three listening stations were analyzed using JASCO's PortListen® system, which tracks vessels using the Automated Identification System (AIS) and automatically measures the source levels of passing vessels, according to the ANSI standard for ship noise measurement (12.64-2009 R2014). The effects of voluntary slowdowns on vessel noise emissions were investigated, on a per-class basis, by comparing measurements of participating vessels with measurements obtained during control periods before and after the trial. Analysis of the trial data showed that speed reductions were an effective method for reducing broadband source levels for five categories of piloted commercial vessels: containerships, cruise vessels, vehicle carriers, tankers, and bulk carriers.
Toward efficient shipping noise probability density function estimation using sea-lane source decomposition and probability theory
Authors: Aulanier Florian J.
Published: October 2018

One goal of the Canadian Ocean Protection Plan (OPP) is to understand the potential effects of shipping noise on endangered whale species in order to mitigate them. Shipping noise environmental impact risk assessment requires the understanding of large scale, high-resolution time-space shipping noise distributions. The computation of such shipping noise probability density functions (pdf) requests considerable computing resources, especially when propagation occurs in complex and varying environments like shallow waters, canyons, or fjords. Besides, input parameters variability and uncertainties analyses require multiple hindcast, nowcast or forecast scenarios to be run when using a direct Monte-Carlo approach. In order to reduce the computation effort, sea-lane shipping traffic decomposition and probability theory are jointly used to derive shipping noise probability density functions with a logarithmic complexity algorithm, as opposed to the linear complexity of direct Monte-Carlo methods. First, a theoretical model is derived for straight shipping routes using simplified logarithmic propagation, validated with numerical examples, and used to perform a sensitivity analysis of shipping noise pdf to speed and route closest point of approach. The improvement in numerical efficiency is shown on a more realistic four sea-lane case scenario mimicking part of the summertime St. Lawrence estuary traffic. Eventually, in situ measurements will be available for comparison.
An introduction to sound in the sea
Authors: Dakin Thomas
Published: October 2018

This introductory talk will address why underwater acoustics are important, its uses, how sound propagates so far in the ocean, man-made sounds, including shipping noise, and the impact of noise in the ocean. A short overview of organizations working on the issue of underwater noise will be given including those around the Salish Sea where the conference is being held. The way sound is measured and analyzed will be shown with local examples of marine life, earthquake and anthropogenic noise. A short exercise to show the effects of acoustic masking will be given, followed by an explanation of echolocation use by the Southern Resident Killer Whales and the implications of acoustic masking on finding food for this local and endangered species.