bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of experience and tonal contour: A preliminary study of perceived duration on Mandarin tones
Authors: Lu Yu-an , Chang Yu-Ming , Chen Yang-Yu , Chen Peichun , Jin Shao-Jie , Lee Cheng-Huan , Lu Waan-Rur , Lu Yen-Ju , Nan Yu
Published: October 2018

Mandarin tones are shown to be produced with different lengths (i.e., from longer to shorter: T3 > T2 > T1 > T4) (cf. Wu & Kenstowicz, 2015). An AX rating experiment in which Taiwan Mandarin listeners were asked to rate the relative durations of syllables ([pa], [pi], [ta], [ti]) manipulated into five different duration steps (290 ms, 320 ms, 350 ms, 380 ms, and 410 ms) in Mandarin tones (high-level T1, rising T2, dipping T3, reduced low-level T3, and falling T4) compared with an anchor stimulus ([pa] with 350 ms in mid-level tone) showed that the complex contour tone (T3) was rated as longer than simple contour tones (T2 and T4) and simple contour tones were rated as longer than level tones (T1 and reduced T3). Between the simple contour tones, T2 was rated as longer than T4. Between the level tones, the reduced T3 was rated as longer than T1. The explanations to these tonal perceptual differences are tied to the typological correlation between rime duration and the complexity of tonal targets (T3 > T2/T4 > T1/T3) (e.g., Zhang 2001) as well as to the listeners’ experience to the durations of different tones (T2 > T4 and reduced T3 > T1).
Acoustic and articulatory evidence on incomplete syllable-final nasal mergers in Taiwan Mandarin
Authors: Chiu Chenhao , Lu Yu-an , Weng Yining
Published: October 2018

Previous studies reported that syllable-final nasals in Taiwan Mandarin, /n/ and /ŋ/, exhibit merging to different degrees in the vowel contexts of /i/ and /ə/ (e.g., Ing 1985, Kubler 1985, Hsu & Tse 2007, Fon et al., 2011). However, the discussion has been mainly on the merging directions, ethnic groups that display the mergers, and attitudes towards the different merging directions. Apart from the large evidence of merging from perceptual identification of the final nasal, this study employs ultrasound imaging technique to examine tongue postures of the syllable-final nasal following /i, a, ə/ vowel contexts. Preliminary results showed that /n/ and /ŋ/ were distinct both acoustically and articulatorily in the context of /a/, echoing earlier findings (e.g., Fon et al., 2011). On the other hand, while the contours of tongue shapes demonstrate extensive overlapping between /n/ and /ŋ/ following /i/ and /ə/, their correspondent acoustics display different degrees of nasalization on the preceding vowels (cf. Chen, 2000). More generally, the results suggest that the merging in syllable-final nasals undergoes an incomplete process and the acoustic contrasts might have lie in the nasalization of the preceding vowels and less so in syllable-final nasals.
The acoustics of the “Witches Valley”
Authors: Berardi Umberto , Iannace Gino , Trematerra Amelia
Published: October 2018

According to legend, witches were women with magical knowledge that with the use of herbs could cure illnesses or perform spells. In 1639, the book “De Nuce Maga Beneventana” was published and described how the place where the “witches” gathered was an area south in South Italy in a long, narrow gorge with high rock walls, called the “Stretto di Barba.” The legend of the witches originated with the invasion of southern Italy by the Longbards who, according to legend, under a walnut tree performed sacred rituals with dances and chants accompanied by the rhythm of drums. To make the rituals more effective, mysterious, and emotionally involving for the people take, it was necessary to amplify the sounds generated. This could only take place in the presence of a narrow gorge with flat and parallel rock walls where the reflecting of the sound generated echoes. The aim of this paper is to verify whether the “Stretto di Barba” has the acoustic characteristics that create echoes and sound amplification effects to confirm the legend that the Longbards performed their rituals here.
The determining factor of L2 vowel perception: The establishment of L2 categories
Authors: Hu Wei , Tao Sha , Wang Lihong , Liu Chang
Published: October 2018

The L2 speech learning theories argue that the perception of L2 phonemes is mainly influenced by the relationship between and among L1 and L2 phonemes. In the present study, we hypothesized that L2 vowel identification is primarily determined by the solidity of the L2 vowel category establishment and the perceptual distance between L2 vowel categories. A group of 31 native Mandarin Chinese-speaking listeners and a control group of 9 native English-speaking listeners participated in the study. All listeners were asked to identify natural English/Chinese vowel identification and categorize and rate synthetic English/Chinese vowels. Major findings include: 1) Chinese learners’ English vowel perception was associated with their capacity to establish English vowel category; 2) the perceptual distance between English vowel contrasts played a key role in Chinese learners’ English vowel perception, rather than the distance between the Chinese vowel and English counterpart. Overall, results of this study suggest that the individual variability of Chinese-native listeners’ English vowel perception is interpreted by the establishment of English vowel categories. [Work supported by China Natural Science Foundation 31628009.]
Study on the structure of an efficient receiver for multi-sensors using direct sequence spread spectrum
Authors: Lee Ahyun , Baek Chang Uk , Jung Ji Won , Do Dae Won
Published: October 2018

In underwater acoustic communication, there has been a lot of interest in detection and acquisition of information about multiple sensors as well as detection of information on a single sensor. However, research on multiple sensors access is lacking. In order to acquire information from each sensor in multiple sensors access underwater communication, we mainly use the spreading method which can obtain information of each sensor individually at the receiving side by multiplying the code with different orthogonal components in the same frequency band. In the case of multiple sensors, successive interference cancellation is used to remove interference from other sensor and apply the RAKE method. However, in a multiple sensor communication environment, if the channel information is not perfect, the performance is reduced. In this paper, we propose a transceiver structure for multiple sensor covert acoustic communication using the spread spectrum method and RAKE method, and propose and effective receiver structure to overcome drawbacks. An actual underwater experiment was conducted to analyze the performance of the covert underwater acoustic communication. The result of experiment indicated that the transmission and receive structure proposed through the actual underwater experiment was well-suited to the communication model for covert multiple accesses.
Potential changes in the communication space of humpback whale social sounds in increasing wind and vessel-dominated noise
Authors: Dunlop Rebecca
Published: October 2018

An animal communication network involves complex acoustic interactions between multiple senders, receivers, and eavesdroppers. Any reduction in communication space, due to signal masking, may have detrimental effects on their ability to obtain social information. Humpback whales use social sounds (vocal and surface-generated percussive sounds) for within-, and between-, group communication. To generate masking models, and infer communication space, changes in signal-above-noise and frequency content of received humpback whale social sounds were modelled with the combined effect of increasing background noise (wind or vessel-dominated) and distance from the source (signalling whale). Results suggest that the signaler’s communication space in increasing wind-dominated noise (shallow water) was maintained out to approximately 3 km by using a Lombard response. In high wind noise (over 105 dB re 1 μPa; 12–15 knots), the vocal communication space was significantly reduced, though the increased use of surface-generated sounds likely aided in maintaining this space. In vessel-dominated noise, communication space was significantly reduced in levels exceeding 110 dB re 1 μPa (vessel within approximately 2 km), with no evidence that the signaler switched to using surface-generated sounds. These models can be updated as more information on humpback auditory capabilities becomes available.
Assessing risk of underwater noise impact on marine mammals throughout a new methodology
Authors: Mauran Marie , Le Courtois Florent , Cachera Marie , Stéphan Yann , Spitz Jérôme , Kinda G. Bazile
Published: October 2018

Shipping noise has been identified as a threat on underwater ecosystems. In particular, several impacts have been documented on cetaceans, e.g., communication’s masking and stress increasing. To assess the risk related to such anthropogenic noise requires both quantifying the noise levels and estimating the distribution of the cetaceans’ population. However, current methods evaluating the risks related to anthropogenic pressures generally rely on strong expert priors, which may be difficult to define. This presentation aims at introducing a new framework for the comparison of anthropogenic pressure levels maps and cetaceans’ distribution in order to infer the risk of impact and provide management solutions. The methodology, combining simple statistical analyses and a theoretical representation tool was applied to the Bay of Biscay using shipping noise model and fin whale observation from regular surveys for the years 2012 and 2016. Relationships between cetaceans’ distribution and noise levels were investigated and linked to mammals theoretical responses to pressure. A trend analysis between 2012 and 2016 was also proposed to identify the noise hotspots. The results were interpreted in both terms of ecological meaning for fin whale and conservation measures for shipping noise, according to marine policies requirements.
Estimating received levels for acoustically tracked whales from Navy mid-frequency active sonar
Authors: Martin Cameron R. , Martin Stephen W. , Henderson E. E.
Published: October 2018

Multi-channel passive acoustic data were collected from bottom-mounted hydrophones off the coast of Kauai, HI at the U.S. Navy Pacific Missile Range Facility’s instrumented range. In February 2017, data were recorded during the Submarine Command Course (SCC) training event that included mid-frequency active sonar (MFAS). Data were post-processed for minke whale (Balaenoptera acutorostrata) vocalizations and MFAS with automated detection, classification, and localization algorithms. Semi-automated processes were used to perform spatio-temporal associations of whale localizations to create individual whale tracks and to associate localized MFAS transmissions with positional data from multiple ships. For each whale track, the received level from each MFAS transmission was estimated using a parabolic equation propagation model that statistically represented the uncertainty of whale location and depth. Exposures were accumulated over the duration of each whale track to estimate the cumulative sound exposure level (cSEL; dB re: 1μPa2s). Twenty-three minke whales were exposed to MFAS during the SCC; the maximum exposure was 169.8 dB cSEL, and the minimum distance to a ship transmitting MFAS was 4.8 km. Currently, statistical analyses of track kinematics and call characteristics are being conducted to quantify any significant changes between animal track kinematics with and without MFAS training presence.
Localizing bioacoustic signals with long-baseline hydrophone arrays
Authors: Hendricks Benjamin T. , Gulliver T. Aaron , Wray Janie L. , Keen Eric M. , Alidina Hussein M. , Picard Chris R. , Meuter Hermann
Published: October 2018

Real-time localization and tracking of vocalizing marine mammals is a powerful tool to a) mitigate the risk of ship strikes and disturbance of the animals as well as b) to understand the impact of anthropogenic noise on habitat use of cetaceans. A long baseline hydrophone array has been installed in Squally Channel, a culturally, ecologically, and economically important marine environment in northern British Columbia, Canada. The array consists of four synchronized bottom-mounted hydrophones that permanently record and radio-transmit data to a land-based laboratory. Automated analysis tools have been developed to detect and localize transient bioacoustic signals from three or more hydrophones in real-time. They comprise the correlation of hydrophone signals, the construction of a replica surface using acoustic propagation models, and signal localization from a spatial likelihood surface. An overview of the localization method is presented. We assess spatial localization precision and discuss random and systematic sources of error stemming from the signal type and quality, bathymetry, sound speed profile, as well as the spatial distribution of hydrophones and acoustic sources. Simulation results are compared to field measurements. Based on our findings, challenges and opportunities associated with localization using long baseline arrays in coastal environments are discussed.
Acoustic signature and footprint of artificial nurseries in harbors
Authors: Lossent Julie , Gudefin Anais , Gervaise Cédric , Foncuberta Amélie , Gilles Lecaillon , Iorio Lucia D.
Published: October 2018

Underwater soundscapes are used as a cue by vertebrate and invertebrate larvae and post-larvae to locate suitable settlement habitats. In the project SEANAPS, we investigated if soundscapes can play a role in ecological restoration actions. We assessed whether Biohuts® (artificial nurseries installed in harbors) have a distinct acoustic signature from the harbor and the natural environments. We conducted four acoustic measurement sessions in Cap d'Agde (France) and a simultaneous monitoring of vagile fauna present in Biohuts®. Directional listening networks allow us to locate the broadband transient sounds from benthic invertebrates and fish, build maps of these emissions and isolate the biophony emitted by the vagile fauna of Biohuts®. The Biohuts® produced 78 emissions/min/m², which represent 200 and 130 times more than a pseudo-natural habitat (seawall) and a natural rocky habitat, respectively. The acoustic footprint of the Biohuts® signatures is 120 m radius in the harbor and 500 m in the harbor road. The harbor road is a naturally silent corridor, which could slow down the larval recruitment by its lack of attractive acoustic signature. This information can be used to resize the network of Biohuts®. Moreover, we demonstrated that the acoustic signature of a Biohut® informs about the vagile fauna it hosts.
Novel sonification and haptic displays of physiologic variables to improve patient safety
Authors: Schlesinger Joseph , Combs Taylor , Holmberg Megan , Jorgensen Seiver , Kultgen Samantha
Published: October 2018

Auditory medical alarms in healthcare are uninformative, poorly localizable, have a low positive predictive value, and are set at thresholds forcing practitioners to be reactive instead of proactive. Sonifying patient physiology as it transitions from normal to abnormal will allow practitioners to respond before the patient status devolves into an emergency. Multimodal interactions have the potential to enhance future sonification tools by reducing alarm fatigue—the addition of haptic cuing to novel physiologic sonification may improve patient safety. To increase the overall efficiency of alarm design in healthcare, we propose reducing alarm fatigue by integrating multisensory streams. We present an experiment that characterizes how the integration of tactile and auditory signals affects the speed and accuracy of alarm responses. Participants received multisensory auditory and haptic input while performing a task designed to tax attentional resources mimicking working in the ICU. Our results indicate there is a trend towards increased perception of change of physiologic variables with concordant haptic stimuli and participants are significantly better at determining the direction of change versus the physiologic variable of change. Future directions include simplification of the sonification schemata and increasing information complexity in the haptic modality to utilize multisensory integration.
Investigating individual susceptibility to the detrimental effects of background noise and reverberation in simulated complex acoustic environments
Authors: Ward Kristi M. , Peng Z. Ellen , Landi Maryam , Burleson Andrew , Souza Pamela , Grieco-Calub Tina M.
Published: October 2018

On a daily basis, individuals perform a variety of tasks in complex acoustic environments that contain background noise and reverberation. Previous research has demonstrated that, when tested in a laboratory setting, background noise and reverberation impair speech recognition and disrupt cognitive processing. These detrimental effects are especially pronounced for young children, older adults, and individuals with hearing loss. However, the specific environmental and individual factors that account for performance declines in the presence of background noise and reverberation, and whether these relations are generalizable to real-world complex acoustic environments, remains poorly understood. In the present study, children and adults performed speech recognition and speech comprehension tasks amidst background noise and reverberation in a state-of-the-art virtual sound room (ViSoR). ViSoR contains a Variable Room Acoustics System, which simulates the acoustic properties of real-world environments in a free-field test setting. Participants also completed standardized measures of attention, auditory working memory, and receptive vocabulary, which will be used to quantify the extent to which individual factors contribute to the observed changes in speech recognition and comprehension. Together, the findings from this study will provide additional insight as to the factors that underlie individual susceptibility to the detrimental effects of background noise and reverberation.
Acoustic conditions for students’ engagement in active learning classrooms
Authors: Hadavi Shiva , Lee Joonhee
Published: October 2018

Educators have developed innovative teaching strategies in order to maximize learning outcomes in classrooms. Active learning classrooms are new learning spaces that facilitate the teaching strategies with enhanced students’ engagement and collaborative discussions. Previous studies showed that the design of the space impacts on students’ achievement. However, acoustic requirements of the active learning classrooms have not been investigated yet. This paper presents, thus, the acoustic conditions of the active learning classrooms located in Montreal. The acoustical parameters such as background noise, reverberation time, and speech transmission index in unoccupied conditions and occupied noise levels during learning activities are examined. The results are compared with conventional classrooms. Since active learning classrooms are more prone to acoustic deficiencies, the results of this paper can provide a better understanding of the acoustic design requirements for these spaces.
Measurement and calculation of lateral trapping strength of focused beams generated by a two-dimensional ultrasound array
Authors: Ghanem Mohamed A. , Maxwell Adam D. , Khokhlova Vera A. , Sapozhnikov Oleg A. , Bailey Michael R.
Published: October 2018

This study is aimed at developing a method to controllably manipulate kidney stones in the human body using a single ultrasound source. Calculation and measurement of the lateral force on a sphere using various acoustic beams (vortex and radially-varying phased beams) were compared. A 256-element, 1.5-MHz array was used to synthesize the beams. Spheres of 1–6 mm (6 < ka < 20) diameter made of glass, ceramic, or brass were positioned on an acoustically matched platform at the focus rigidly attached to the transducer by a frame. The transducer and platform were rotated to the angle at which the trapped sphere fell. The acoustic power was <9 W and was adjusted by the duty cycle (10–60%) to control the range of the trapping angle. Maximum temporal average intensity ISPTA was 46.5 W/cm2. The acoustic force was calculated numerically as in Sapozhnikov and Bailey [JASA, 133, 616 (2013)] and the angle calculated with static force equilibrium equation. Good agreement between calculation and measurement was observed, with an average error in angle measured of 11.3%. The maximum lateral forces were 80% of the axial radiation force and 52% the gravitational force. [Work supported by NIH P01-DK043881, K01-DK104854, R01EB7643, and RBBR 17-02-00261.]
Challenges and opportunities in bridging behavior, physiology, and anatomy in translational hearing research
Authors: Lauer Amanda , Kim Ye-hyun , Schrode Katrina
Published: October 2018

The Acoustical Society of America has a long, rich history of physiology research aimed at understanding the neural mechanisms underlying hearing and hearing dysfunction. In particular, this research has included pivotal studies in animal models that reveal the neurobiology of hearing and hearing disorders. More recently, research in animal models and research in human subjects have been considered in completely separate conferences or sessions. This situation presents a barrier to communicating important scientific information and fostering collaborations that bridge the gap between research in animal models and human listeners. It is crucial that the two types of research interface and inform one another to maximize translational potential and converge on fundamental knowledge. Experimental manipulations can be performed in non-human animals that cannot be performed in humans, but human and non-human animals can also be tested using similar techniques to increase translatability. Examples of mouse models tested using detailed analysis of synapse-level changes, clinically relevant evoked potentials, and behavioral tests will be presented. Areas for mutually beneficial interdisciplinary investigation will be discussed with the intention of inspiring new lines of communication between researchers focused on non-human animal and human subjects research.
Suprathreshold hearing in middle age and relationship to cochlear synaptopathy
Authors: Bharadwaj Hari M. , Flesher Brooke , Mai Alexandra , Dougherty Kelsey , Simpson Jennifer M. , Heinz Michael G.
Published: October 2018

Animal models have demonstrated that the afferent synapses and nerve terminals innervating the cochlea are vulnerable to damage from acoustic overexposure and aging. This synaptopathy can occur without hair-cell loss, or more severely when accompanied by permanent audiometric shifts. In humans, postmortem temporal bone studies have shown that cochlear synaptopathy occurs throughout adulthood, decades before audiometric loss nominally occurs. However, effective non-invasive assays of synaptopathy have yet to be established in humans (or genetically heterogeneous animal cohorts). Moreover, whether synaptopathy contributes to age-related temporal perception deficits is debated. We are currently studying young and middle-aged humans with clinically “near-normal” audiograms using physiological and perceptual measures. Preliminary results suggest that although high-frequency audiometric shifts occur with age as previously known, middle age per se is associated with physiological effects consistent with cochlear synaptopathy. Further, we find that the effects of age and threshold elevation can oppose and obscure one another on certain perceptual measures. Finally, with speech-in-noise measures designed to degrade high-frequency envelope cues, perceptual deficits associated with middle age per se are apparent and consistent with synaptopathy. These results will be discussed in light of the ongoing debate about the prevalence and consequences of synaptopathy in humans.
Geminated liquids in Japanese
Authors: Morimoto Maho , Kitamura Tatsuya
Published: October 2018

Liquid geminates are uncommon and disfavored in Japanese native phonology. However, instances of emphatic expressions and loanwords from languages with liquid geminates such as Italian or Arabic suggest that they are not impossible. The current study examines the durational, acoustic, and articulatory properties of geminated liquids in Japanese to obtain further insights into the nature of /r/ in Japanese and the process of gemination in general. We report on a production experiment whereby eight native speakers of Japanese pronounced mimetics of the form CVCVCVCV with and without emphatic gemination (e.g., kirakira > kir:akira “shiny”). In addition to the audio, tongue movements were recorded using the EMA technology. Preliminary durational analysis suggests that singleton-geminate ratio is about 1:3, which is slightly larger than the ratios previously reported for geminated obstruents. We explore what articulatory strategies speakers employ to lengthen the liquid consonant whose prototypical singleton production is [ɾ].
Distributional patterning of reflex cough during telephone conversations
Authors: Llorens Mairym
Published: October 2018

Reflex cough and speech are two behaviors that make use of the same end effectors—the respiratory and vocal tract subsystems. How do talkers engaged in conversation resolve conflicts between the communicative necessities involved in speech planning and their physiological reflexes? Coughing is a complex reflex arc triggered in the airway that leads to an urge to cough and, at some latency, the deployment of a coordinated vocal-respiratory response to that urge. However, research on factors that influence urge-cough latency is limited. Hypothesizing that talkers may actively delay coughing, this present study examines 200 instances of reflex cough from the Switchboard and CallHome corpora of spontaneous, dyadic telephone speech. Coughing events in both corpora are always flanked by acoustic silences, with the majority of coughing events occurring at interlocutor turn exchanges. Assuming that urges to cough can arise at anytime, we interpret the restriction of cough occurrence to pauses and turns as evidence that talkers can and do delay coughing until the end of their intonational phrases or to floor exchanges with their interlocutor. This further indicates a degree of linkage between the non-speech motor system and the prosodic speech planning system. [Work supported by NIH.]
Cross-linguistic lateral bracing: An ultrasound study
Authors: Tong Felicia , Liu Yadong , Choi Dawoon , Keough Megan , Gick Bryan
Published: October 2018

Lateral bracing refers to intentional stabilizing of tongue contact with the roof of the mouth along the upper molars or the hard palate. Previous research has found evidence of lateral bracing in individual speakers of six languages [Cheng et al. 2017. Can. Acoust. 45, 186]. The current study examines lateral bracing cross-linguistically at a larger scale using ultrasound technology to image tongue movement. We tracked and measured the magnitude of vertical tongue movement at three positions (left, right, and middle) in the coronal plane over time using Flow Analyzer [Barbosa, 2014. J. Acoust. Soc. Am. 136, 2105] for optical flow analysis. Preliminary results across all languages (Cantonese, English, French, Korean, Mandarin, and Spanish) show that the sides of the tongue are more stable than the center and maintain a relatively high position in the mouth throughout speech. The magnitude of movement at the sides is significantly smaller than at the center of the tongue. Further, lateral releases vary in frequency for different languages. This evidence supports the view that bracing is a physiological property of speech production that occurs irrespective of the language spoken. [Funding from NSERC.]
Pitch duration as a cue for declination
Authors: Wu Lihan , Lin Hua
Published: October 2018

An utterance of a language often demonstrates the effect of declination, usually understood broadly as a reduction in certain physical or acoustic signals. Previous research on declination focuses primarily on the acoustic measures of pitch (such as the movement of pitch or the alternation of pitch span) or intensity. Neglected in the matter is the third acoustic dimension of speech duration. This paper reports on an experiment on declination focusing on pitch duration. The language studied is Mandarin Chinese. Six native Mandarin speakers are recruited. A total of 864 utterances of 2-to-9 syllables in four tones and four functional intonations are recorded and analyzed on Praat. The results show that the declination of pitch duration goes side by side along the pitch declination, both of which share the same physiological basis. Specifically, (1) the average pitch duration within the prosodic unit decreases gradually from the sentence-initial prosodic unit to the sentence-final one, (2) the pitch duration of the left-most syllable of the prosodic unit decreases gradually from the sentence-initial prosodic unit to the sentence-final one, and (3) the pitch duration of the right-most syllable of the prosodic unit decreases slightly from the sentence-initial prosodic unit to the sentence-final one.
Fully-automated tongue detection in ultrasound images
Authors: Karimi Elham , Menard Lucie , Laporte Catherine
Published: October 2018

Tracking the tongue in ultrasound images provides information about its shape and kinematics during speech. Current methods for detecting/tracking the tongue require manual initialization or training using large amounts of labeled images. This work introduces a new method for extracting tongue contours in ultrasound images that requires no training or manual intervention. The method consists in: (1) application of a phase symmetry filter to highlight regions possibly containing the tongue contour; (2) adaptive thresholding and rank ordering of grayscale intensities to select regions that include or are near the tongue contour; (3) skeletonization of these regions to extract a curve close to the tongue contour; and (4) initialization of an accurate active contour from this curve. Two quality measures were also developed that predict the reliability of the method so that optimal frames can be chosen to confidently initialize fully automated tongue tracking. Experiments were run on 16 free speech ultrasound recordings from healthy subjects and subjects with articulatory impairments due to Steinert's disease. Fully automated and semi automated methods result in mean sum of distances errors of 0.92mm + /- 0.46 mm and 1.04 mm + / 0.5513 mm, respectively, showing that the proposed automatic initialization does not significantly alter accuracy.
Speech adaptation to palatal perturbation: Evidence for sensorimotor reorganization across the workspace
Authors: Shiller Douglas , Barbier Guillaume , Menard Lucie , Baum Shari
Published: October 2018

Competent speakers demonstrate a high degree of precision in speech production, but also considerable flexibility in speech motor patterns used to attain speech goals. This flexibility is evident in studies examining adaptation to sensory perturbations, including physical manipulations that alter both auditory and somatosensory feedback (e.g., using a palatal prosthesis to disrupt the production of the alveolar fricative /s/). While the acoustic effects of such perturbations (and subsequent adaptation) have been well explored, their underlying articulatory basis remains poorly understood. In this study, we explored speech adaptation to a palatal perturbation in 9 adult speakers using acoustic and articulatory measures of adaptation (using electromagnetic articulography) during the production of various consonants and vowels. Acoustic measures showed effects of both the perturbation and subsequent compensation (following 15 minutes of speech practice) across the consonants and vowels. Analysis of tongue kinematics confirmed the global nature of these effects, including significant changes in sounds involving no physical interaction with the palate. Furthermore, directional analyses revealed a degree of fine-tuning in motor adaptation across phonemes. The findings indicate that even localized changes in palate shape induce complex compensatory changes in speech motor control across the articulatory workspace.
Nasal rustle: An evidence-based description, II
Authors: Rollins Michael , Oren Liran , Padakanti Srujana , Gutmark Ephraim , Kummer Ann W. , Boyce Suzanne E.
Published: October 2018

This research extends a previous study investigating the sound source of audible nasal emissions associated with a small velopharyngeal (VP) opening (herein “nasal rustle,” but also “nasal turbulence” elsewhere). This extension includes more speech sounds than the original study, which only considered /s/. Speech sounds susceptible to nasal rustle were recorded from ten pediatric patients with VP insufficiency via high-speed nasopharyngoscopic video at the superior VP port and simultaneous nasometry. The total pixel intensity was summed in each video frame to generate a video intensity signal. For each speech sound token, a cross-correlation was computed between this video intensity signal and each of the nasometer’s acoustic signals; this measures similarity in frequency content between motion at the superior VP port and acoustics exterior to the lips and nares, respectively. The difference between the video-nasal cross-correlation and the video-oral cross-correlation over a frequency bandwidth including the dominant frequencies observed in the video intensity signal (<100 Hz) has a positive association with the number of mucus movements, meaning the motion of mucous secretions correlates more strongly with acoustic energy exterior to the nares than exterior to the mouth. This indicates that mucus motion could be a dominant sound source of nasal rustle.
Detection and tracking in very shallow water
Authors: Jobst William , Whited Lawrence , Smith David
Published: October 2018

In our previous work, we demonstrated a low power, m-sequence based, bistatic acoustic system that detected and tracked a -20 dB target at a range of 172 m in a water depth of 2 m. To our knowledge, similar results have not been obtained with non-biological systems. Unfortunately, we were not able to repeat these results under similar, or possibly better, environmental conditions. This work addresses the reasons for failure to reproduce our original experimental results and suggests an approach that should result in very shallow water detection and tracking at much longer range.
Monitoring of moving surface ship using a four-element planar hydrophone array installed on the seabed
Authors: Byun Sung-Hoon , Kim Sea-Moon
Published: October 2018

This talk presents the analysis result of underwater sound measurement data which were recently gathered in the shallow water near South Korea. For the underwater sound measurement, a four-element planar hydrophone array developed by KRISO was installed on the seabed and recorded a month-long acoustic data. The result shows that the measured sound level is usually higher in the morning time and this is ascribed to the surface boats which are presumably in fishing activity. We deal with the identification of the sound sources via various modulation analysis methods which can discriminate the sound induced by rotating propellers and also discuss the direction finding by beamforming of the planar hydrophone array data. [This work was financially supported by the research project PNS3120 funded by KIGAM.]
Comparing neural networks with conventional classifiers for fin whale vocalizations in beamformed spectrograms of coherent hydrophone array
Authors: Garcia Heriberto A. , Penna Seth , Topple Jess , Makris Purnima R.
Published: October 2018

A large variety of sound sources in the ocean, including biological, geophysical and man-made activities can be simultaneously monitored over instantaneous continental-shelf scale regions via the passive ocean acoustic waveguide remote sensing (POAWRS) technique by employing a large-aperture densely-sampled coherent hydrophone array. Millions of acoustic signals received on the POAWRS system per day can make it challenging to identify individual sound sources. An automated classification system is necessary to enable sound sources to be recognized. Here a large training data set of fin whale and other vocalizations are gathered after manual inspection and labelling. Next, multiple classifiers including neural networks, logistic regression, support vector machine (SVM) and decision tree are built and tested for identifying the fin whale and other vocalizations from the enormous amounts of acoustic signals detected per day. The neural network classifier will use beamformed spectrograms to classify acoustic signals, while logistic regression, SVM, and decision tree classifiers will use multiple features extracted from each detection to perform classification. The multiple features extracted from each detection include mean, minimum, and maximum frequencies, bandwidth, signal duration, frequency-time slope, and curvature. The performance of the classifiers are evaluated and compared using multiple values including accuracy, precision, recall, and F1-score.
Quantifying seabed and other environmental information contained in ocean ambient noise
Authors: Siderius Martin , Gebbie John
Published: October 2018

The ocean ambient noise field contains a surprising amount of information about the environment. Information about the seabed includes, layering structure, sound speed, density, and attenuation. There is also information about the ocean environment such as water column sound speed, volume attenuation, and the sea-state. Estimators for these quantities have been developed based mostly on vertical hydrophone arrays and beamforming. Although this has led to some simple and direct estimates for important quantities such as bottom loss, these estimates may be less than ideal in some cases. For example, when using inadequately sampled arrays or in certain unfavorable measurement geometries. The Fisher information can be used to quantify the basic information available in the noise measurements; and its inverse, the Cramér-Rao lower bound (CRLB), provides the lower limit on the variance of any unbiased estimator. The CRLB can be used to study the feasibility of various measurement configurations and parameter sensitivities. In this presentation, an overview will be given specifying the variety of environmental information contained in ocean noise. Parameter sensitivities and performance of beamforming estimators relative to the CRLB will also be discussed. [Work supported by the Office of Naval Research Ocean Acoustics Program.]
Trans-dimensional geoacoustic inversion on the New England Mud Patch using modal dispersion data
Authors: Bonnel Julien , Dosso Stan E. , Eleftherakis Dimitrios , Chapman N. Ross , Dall'Osto David R. , Dahl Peter H.
Published: October 2018

This paper presents trans-dimensional geoacoustic inversion of two low-frequency broadband signals recorded during the Seabed Characterization Experiment (SBCEX). The considered sources are a chirp emitted by a towed J15 source and an underwater impulse created by a combustive sound source (CSS). Corresponding received signals are recorded on single hydrophones, and the two source/receiver configurations are reciprocal, on the same track. Input data for inversion are modal time-frequency dispersion curves, estimated using warping. Inversion is then performed within a Bayesian framework. A trans-dimensional inverse algorithm is used to estimate the model parametrization (i.e., number of seabed layers), and the mode covariance matrices are estimated as a first-order autoregressive error process. Inversion results on the two reciprocal tracks are consistent with the modal information available in each dataset. Results are also consistent with what is known about the area.
Some comments on acoustic sensing at a single point in space
Authors: D'Spain Gerald L. , Pagniello Camille , Rowell Timothy
Published: October 2018

The directionality provided by an acoustic vector sensor can be viewed in the context of a Taylor series expansion of the acoustic pressure field. From this perspective, acoustic pressure and acoustic particle velocity are but two of an infinite number of acoustic field variables. The purpose of this presentation is to examine some of the properties of these higher order field variables, including their energetics and the behavior of their spatial cross spectra in homogeneous, isotropic noise. Analytical expressions for those spatial cross spectra involving the normal strain rate parallel to the direction of separation decrease rapidly with increasing separation, and then continue to oscillate with a sinc function behavior. In contrast, those involving the normal strain rate perpendicular to the direction of separation decrease more slowly so that significant positive coherence exists at half-wavelength spacing, but then decay to, and remain near, zero at larger spacings. Accurate estimates of the range to a near-field point source can be obtained from the in-phase and quadrature components of normal strain rate with respect to pressure. Do animals in the ocean exploit the properties of these higher-order field variables?
Exploiting ambient noise for coherent processing of mobile vector sensor arrays
Authors: Sabra Karim G. , Nichols Brendan , Martin James S. , Verlinden Christopher M.
Published: October 2018

A network of mobile sensors, such as vector sensors mounted to drifting floats, can be used as an array for locating acoustic sources in an ocean environment. Accurate localization using coherent processing on such an array dictates the locations of sensor elements must be well-known. Achieving this for a mobile, submerged array composed of individual drifting sensors is usually challenging. However the coherent processing of the ambient acoustic noise between sensor pairs can provide the separation distance between them and thus an opportunity to correct sensor location errors. Here a stochastic search algorithm is presented for identifying hidden coherent noise arrivals when the separation distance is changing faster than the required averaging time to extract such arrivals from a fixed sensor pair. The accuracy of this method matches that of GPS-derived array element positioning and its performance is shown to be improved when using directional vector sensors instead of omnidirectional hydrophones. The proposed approach is demonstrated experimentally using ambient noise recorded by drifting vector sensors deployed in the Long Island Sound and is used to enable tracking of surface ships by coherent processing of the drifting sensors.
Frequency warping transform of the vertical energy flux and its use for passive source ranging
Authors: Qi Yubo , Yu Mengxiao , Zhou Shihong , Zhang Renhe , Du Shuyuan , Sun Mei
Published: October 2018

The frequency warping transform of the vertical energy flux and a passive impulsive source ranging method with a single acoustic vector sensor are presented in this paper. The cross-correlation component of two different modes in the vertical energy flux is transformed into separable impulsive sequence. With a guide source, the source range is extracted from the relative delay time of the impulsive sequence. Comparing with warping the pressure autocorrelation function, there is no need to delete the modal autocorrelation component for warping the vertical energy flux, especially for its real part. Besides, the source ranging result based on the time delay of the warped vertical energy flux is much better for closer range. The frequency warping transform of the vertical energy flux and the passive source ranging method are veriﬁed by experimental data.
Implementation of Nuttall’s vector-sensing target motion analysis algorithm
Authors: Cray Benjamin
Published: October 2018

Direction cosine measurements, obtained from an array of vector sensors, are processed and used to estimate the location and motion of a moving source. Nuttall derived this unpublished TMA algorithm in 2006, which recently was reviewed, implemented, and evaluated using newly collected experimental data. Both stationary and moving sources are examined. It is assumed that the array element positions are known; however, at any given time instant, the measured direction cosines are presumed noisy. Originally, Nuttall’s formulation only utilized the three orthogonal components of acoustic particle velocity at each array location, however adding acoustic pressure is straight-forward and resolves bearing ambiguity. For a non-moving source, the TMA processor (linear in source position variables) generates a 3-by-3 set of simultaneous equations, with solution vector for the source position (xs, ys, zs). Range from any array element to the source can then be estimated. For a moving source, a 6-by-6 set of simultaneous equations is obtained; the solution vector is now the initial source position (xs, ys, zs) and the source velocity components (a, b, c). It is presumed that the source velocity is constant over the observation interval.
A tale of three models, two loudspeakers, and one install
Authors: Lamour Croteau Liz
Published: October 2018

It’s commonplace to use an acoustic modeling software to confirm room conditions and loudspeaker coverage when designing a sound system. It is also becoming more commonplace for different loudspeaker manufacturers to publish—and require—the use of their own “homemade” proprietary software for modeling. In this survey, three separate software applications were utilized to model two loudspeaker options for a lecture hall at a local university with one loudspeaker solution ultimately being selected and installed. The university required graphic evidence of adequate coverage from both solutions and an on-site loudspeaker “shoot out” to determine final loudspeaker selection. Data collected along the journey includes room coverage maps for each loudspeaker with graphic elements adjusted for close-to-equal comparison, rough pink noise octave-band measurements during the demo, and final installed analysis and comparisons.
Method of predicting Composite Sound Transmission Class rating of composite wall assemblies that do not extend to deck
Authors: Pettyjohn Steve
Published: October 2018

Predicting the sound transmitted through a partition can be very difficult because of the range of unknowns. Typically, Sound Transmission Class, STC, data provided by vendors is available to select the appropriate wall or floor/ceiling assembly. However, when partitions are made of multiple building elements, the difficulty increases. Calculating the area of each element and having an STC rating for each element allows the Composite STC rating to be calculated from the total area divided by the Total area times the transmission loss coefficient. The larger the STC rating, the smaller the Transmission Loss Coefficient. Thus, even small areas with very low STC ratings diminish the Composite STC rating. For a wall partition that stops 15 cm above the ceiling, the area and STC rating of the common area must be included in the calculation. This means that the area of the ceiling, the penetrations of the ceiling, and the area from the top of the partition must be computed. A method has been developed to account for all the paths between two spaces that provides a good estimate of the Composite STC/NIC rating of any partition. Examples and details will be provided.