bluuebunny/crossref_metadata_2025 huggingface dataset:
Improving the quality of speech in the conditions of noise and interference
Authors: Kostek Bozena , Kąkol Krzysztof
Published: October 2018

The aim of the work is to present a method of intelligent modification of the speech signal with speech features expressed in noise, based on the Lombard effect. The recordings utilized sets of words and sentences as well as disturbing signals, i.e., pink noise and the so-called babble speech. Noise signal, calibrated to various levels at the speaker's ears, was played over two loudspeakers located 2 m away from the speaker. In addition, the recording session included utterances in quiet, which constitute a reference to the received speech signal analysis with the Lombard effect. As a part of the analysis, the following parameters were examined with regard to prosody: fundamental frequency F0, formant frequencies of F1 and F2, duration of the utterance, sound intensity, etc., taking into account individual sentences, words, and vowels. The PRAAT program was used to process and analyze speech signals. Next, a method for modifying speech with the features of speech spoken in noise was proposed. Subsequent analyzes have shown that noisy speech modified by the Lombard effect features is characterized by higher values of the PESQ (perceptual evaluation of speech quality) speech quality indicator compared to noisy speech without the features incorporated.
Contribution of the tongue tip retraction in the articulation of high vowels
Authors: Jang Hayeun
Published: October 2018

This study shows that the retraction of the tongue tip contributes to the raising of the tongue body in the articulation of high vowels /i/ and /u/ by using qualitative simulations of tongue deformation by using a biomechanical 3D tongue model of Artisynth (Lloyd et al. 2012) and the analysis of tongue configuration in X-ray microbeam data (Westbury 1994). The simulations qualitatively replicated the tongue shapes at the temporal mid-point of /i/ and /u/ in rtMRI data by manipulating the activation values of tongue muscles in Artisynth. The results show that the tongue tip retraction helps to raise the tongue body higher in both /i/ and /u/. In the simulations of /i/, the tongue tip retraction raises the tongue body even without moving the tongue body. The results of x-ray microbeam analysis confirm those findings of simulations. The mixed linear regression model of tongue configurations in the tasks of sentence and paragraph production shows that more tongue tip retraction (a shorter horizontal distance between two anterior tongue pellets) significantly correlates with a higher position of the tongue body (higher one between two posterior tongue pellets) in both /i/ and /u/ and the correlation is stronger in /i/ than in /u/.
Articulatory feature extraction from ultrasound images using pretrained convolutional neural networks
Authors: Xu Kele , Zhu Jian
Published: October 2018

Feature extraction is of great importance to ultrasound tongue image analysis. Inspired by the recent success of deep learning, we explore a novel approach to feature extraction from ultrasound tongue images using pre-trained convolutional neural networks (CNN). The bottleneck features from different pre-trained CNNs, including VGGNet and ResNet, are used as representations of the ultrasound tongue images. Then an image classification task is conducted to assess the effectiveness of CNN-based features. Our dataset consists of 20,000 ultrasound tongue images collected from a female speaker of Mandarin Chinese, which were manually labeled as containing one of the following consonants: /p, t, k, l/. Experiment results show that the Gradient Boost Machines (GBM) classifiers trained on the CNN-based features achieve the best performance, with a classification accuracy of 92.4% for ResNet and 91.6% for VGGNet, outperforming the benchmark GBM classifier trained on the features extracted using Principal Component Analysis (PCA), which only achieves an accuracy of 87.5%. In this preliminary dataset, our method of feature extraction is found to be superior to the PCA-based method. This work demonstrates the potential of applying the pre-trained convolutional neural networks to ultrasound tongue image analysis task.
A mechanical deformation model of the tongue during speech production considering personalized anatomical structure
Authors: Takenaka Shun , Yoshinaga Tsukasa , Nozaki Kazunori , Ii Satoshi , Wada Shigeo
Published: October 2018

In the previous studies, several tongue models have been developed to investigate the relationship between the contraction of tongue muscles and the deformation of the tongue during speech. However, the tongue deformation is highly subject-specific and their modellings are insufficient to uncover the detailed mechanism. In this study, a mechanical tongue model considering personalized anatomical structure of tongue myofiber is proposed. A set of reference geometries of tongue and jaw is constructed from the medical images of computer tomography (CT) and the magnetic resonance imaging (MRI) for a Japanese male adult. In addition, we reflect the information of tongue myofiber orientations evaluated from the medical images of diffusion tensor imaging (DTI) on the model using a smoothing extrapolation technique. The tongue deformation is calculated by solving a force-equilibrium equation using a continuous Galerkin finite element method with a hyperelastic material, where the deformation is driven by active contraction of the tongue muscles. We examined the tongue deformations under several contraction conditions during speech and confirmed reasonable numerical reproductions of actual tongue motion and shape. These results indicate that the proposed model reflecting personalized information including myofiber orientations has a potential to identify the tongue muscle contractions in speech production.
Co-mingling effects of dialectal and stylistic variation due to choice of speaker normalization
Authors: Rankinen Wil A. , de Jong Kenneth
Published: October 2018

This paper explores how a speaker normalization routine can result in co-mingling effects of dialectal and stylistic variation. To this end, the paper examines a database of vowel formants in a passage and a wordlist task collected from 88 monolingual American English speakers in Michigan’s Upper Peninsula; this corpus is further stratified by ethnic-heritage, age, sex and educational attainment. Two different speaker normalization routines, Lobanov (Adank et al., 2004) and Labov ANAE (Labov et al., 2006), were used; however, each routine yielded differences in a paralleled analysis. The Lobanov normalization routine removes much of the ethnic-heritage effect that appears in the analysis using the Labov ANAE normalization routine. Examining the cause of these different results reveals that 1) the Lobanov routine removes any mean shifts in formant values that run orthogonal to anatomical variation (i.e., vocal tract length effects) and 2) the ANAE routine only removes shifts which are correlated across formants. The ethnic-heritage effect in this dataset involves mean shifts that are negatively correlated to typical anatomical variation, which results in the ANAE routine potentially amplifying such effects. We discuss the import of these findings for vowel space variation and language change.
Comparing passive localization methods for ocean vehicles from their underwater sound received on a coherent hydrophone array
Authors: Zhu Chenyang , Wang Delin , Tesei Alessandra , Ratilal Purnima
Published: October 2018

Simultaneous localization and tracking of multiple ocean vehicles over instantaneous continental-shelf scale regions using the passive ocean acoustic waveguide remote sensing (POAWRS) technique employs a large-aperture densely-sampled coherent hydrophone array system to monitor the underwater sounds radiated by ocean vehicles. Here, particle filtering is implemented for bearings-only localization and tracking of surface ships where the estimated bearing-time trajectories of ship-radiated underwater sound detections are used as inputs to provide two-dimensional horizontal position estimates. Coherent beamforming of the acoustic data received on the hydrophone array not only provides estimates of ship bearing, but also significantly enhances the signal-to-noise ratio. Results of passive acoustic surface ship localization and tracking from recordings in the Gulf of Maine and the Norwegian Sea are presented. The particle filtering approach for passive source localization are compared with three other approaches: moving array triangulation (MAT), array invariant (AI), and modified-polar-coordinates extended Kalman filter (MPC-EKF). The passive source localization accuracies, determined by comparison with the GPS-measured position of the surface ships, are dependent on numerous factors such as source-receiver geometry, range, and relative speed. By combining several of these approaches, which have respective pros and cons under different circumstances, the surface ships can be localized with improved accuracy.
Tracking sperm whales (Physeter macrocephalus) detected with irregular time intervals
Authors: Bai Tian , White Paul
Published: October 2018

Passive acoustic monitoring (PAM) is a method that has been proved to be a powerful tool for monitoring sperm whales. Sperm whales frequently emit loud, short duration, clicks for the purposes of echolocation. The clicks are emitted at intervals of typically once per second, but the exact interval between pulses varies irregularly. To achieve the monitoring goals, it is necessary to localise the vocalising animal. This is typically achieved by detecting the animal’s echolocation clicks on a hydrophone array, estimating time delays between clicks and then employing a localisation algorithm. By adopting a tracking-based approach we are able to smooth the results, based on a model of whale motion, to remove noise and improve the estimates of location. The paper will consider the problem of tracking whales using the data from fixed bottom mounted sensors and using a tracking algorithm to follow the motion of such animals. The tracking will be implemented using a Kalman filter, but in this instance that filter needs to be designed to allow for data measured at irregular intervals. The method uses a version of the Kalman filter using a varying time-step. The time-step varying Kalman filter is applied to track data from simulated and measured datasets. The measured dataset is publicly available as part of the 2nd International Workshop on Detection and Localisation of Marine Mammals, Monaco, 2005 and comprises of a single animal moving within an array of 5 sensors.
Sequential filtering and linearization for inversion in the Seabed Characterization Experiment
Authors: Michalopoulou Zoi-Heleni
Published: October 2018

Using particle filtering we can track arrival times at spatially separated phones and identify them as distinct paths. This method is very well suited to data collected during the Seabed Characterization Experiment at 16 vertically separated phones of an MPL vertical line array. The source signals are mid-frequency linear frequency modulated pulses. Several paths can be identified in the received time-series including the bottom bounce and sediment reflection. These provide a plethora of information on the seabed properties. We combine the particle filter with a linearization approach that first allows us to resolve the geometry of the experiment. For that we build a Jacobian matrix with time derivatives with respect to the unknown parameters. We proceed with an exhaustive search for sediment parameters such as sound speed and thickness. Probability density functions of arrival times are propagated backwards through the inverse model, providing estimates of densities for the unknown parameters. [Work supported by ONR.]
Insights into sediment acoustics from analytic solutions of forward problems
Authors: Godin Oleg A.
Published: October 2018

Closed-form analytic solutions of wave equations are available for a rather limited subset of geoacoustic models of practical interest. Apart from elucidating the challenging underlying physics of wave propagation, the analytic solutions prove to be useful in sediment acoustics when these predict distinct, identifiable features of measured acoustic fields. Theoretical predictions can be used then to identify or constrain the type of sediment stratification, lead to quick, low-parameter inversions, guide application of statistical inversion methods, and help with interpretation of their results. In this paper, application of analytic solutions of forward problems to acoustic remote sensing of marine sediments will be illustrated by results obtained in a few experiments, which involve observations of slow interface waves near the seafloor and/or resonance peaks in either bottom-reflected energy or in the power spectrum of ambient noise. Coupling between shear and compressional waves in the stratified ocean bottom plays a key role in both examples. [Work supported, in part, by ONR.]
Application of geoacoustic inference for ecosystem monitoring of a seagrass meadow
Authors: Ballard Megan S. , Sagers Jason D. , Venegas Gabriel R. , Lee Kevin M. , McNeese Andrew R. , Wilson Preston S. , Rahman Abdullah , Dubin Justin T.
Published: October 2018

Seagrasses provide a multitude of ecosystem services: they alter water flow, cycle nutrients, stabilize sediments, support the food web structure, and provide a critical habitat for many animals. However, due to threats to seagrass meadows and their associated ecosystems, these habitats are declining globally. Since the biological processes and physical characteristics associated with seagrass are known to affect acoustic propagation due to bubble production, which results in dispersion, absorption and scattering of sound, acoustical methods are proposed to assess the health of seagrass meadows. For this purpose, an experiment was conducted in the Lower Laguna Madre where the seabed was covered by a dense growth of Thalassia testudinum. During the experiment, a combustive sound source was used to produce broadband signals at ranges of 20 m to 1000 m from the receiver location. Three sensors were positioned at the receiver location: two hydrophones located within and above the seagrass canopy, and a single-axis geophone. The data were analyzed for the purposes of inferring environmental parameters in the seagrass meadow and to investigate the feasibility of using acoustical methods to monitor ecosystem health. Initial results indicate that water column void fraction can be inferred. [Work sponsored by ARL:UT IR&D and ONR.]
Characteristics of very-low-frequency pulse acoustic fields measured by vector sensor and ocean bottom seismometer in shallow water
Authors: Zhang Renhe , Zhou Shihong , Qi Yubo , Liang Yuquan , Sui Yuanjie
Published: October 2018

In the marine environment, the effects of the seafloor and subbottom elastic media on the propagation of very low frequency (VLF) sound wave should be considered. In order to understand the mechanism of seismoacoustic field propagation, a very-low-frequency sound propagation experiment was conducted in shallow water using seafloor-located acoustic vector sensor and ocean bottom seismometers (OBS) in December 2017. The water depth is about 100 m. Pulse sources detanoted at depths of 7 m and 50 m were employed to emit the VLF signals. Comparing the signals received by OBS with that of the acoustic vector sensor, a narrow-band wave package group at VLF had been observed, which was excited by the interaction of acoustic waves in water with the layered shear seabed. In this paper, the pulse signals are used to analyze the characteristics of sound propagation and spatial correlation, amplitude and phase structure of separated normal modes based on warping transform, horizontal and vertical acoustic energy flow at different ranges. The time arrival structure and time expansion of the elastic-bottom-induced wave package group and its relationship with source distance and depth are also analyzed.
Practical use and extension of methods for improved source realism in auralizations
Authors: Mayell Marcus R. , Dulworth Nicolaus , Miller Gregory A.
Published: October 2018

The effectiveness of an auralization as a learning and decision-making tool is greatest when listeners are able to actively engage in a plausibly realistic experience. Accuracy of the spatially varying timbral behavior of various sound sources within acoustic models has been found to greatly improve the perceived realism in auralizations. Multi-channel/phantom source modeling techniques offer the ability to better emulate sources through improved timbral representation, more authentic 3D imaging, and dynamic directivity—characteristics limited or lost by traditional point source representation methods. This technique realizes and expands upon methods using multichannel recording techniques that have been previously proposed. It offers the ability to expedite the source capture and implementation process, and to more easily represent larger/multiple sound sources while improving the feasibility and opportunity for high quality source content.
Speech Privacy Class calculations and post-construction measurements of a corporate workplace tenant improvement project
Authors: Manley David
Published: October 2018

LEED interior design and construction projects IEQ acoustical credits are particularly difficult to achieve due to broad scope requirements and restrictive credit language. Specifically, the high composite sound transmission requirement between private offices and hallways. DLR Group acoustical staff proposed an alternative compliance path and evaluation focused on lower STC rated partitions with the addition of sound masking systems to increase the background noise levels, with the goal of achieving an equivalent level of speech privacy between offices and hallways. Speech Privacy Class as detailed in ASTM E2638-10 was used as the evaluation metric. Difficulties in analysis and design stage assessment included unknown level difference of constructed partitions and entry doors, correlating subjective Client expectations to objective SPC ratings, and Client sign-off on sound masking approach. Post-construction measurements were conducted before and after sound masking system installation. Significant improvements in objective SPC ratings were measured, although targeted design goal SPC ratings were not achieved in all cases. Measured noise level differences of the glass storefront office partitions and measured sound masking noise spectra were compared to design stage values for further process refinement. Completed space measurement results and design stage comparisons will be reviewed and discussed.
On-stage energy enhancement in a vineyard concert hall verified by scale model measurements
Authors: Phan Anh-Nguyen , Chiang Weihwa , Chen Yi-Run
Published: October 2018

Reflective surface area near the stage of a vineyard concert hall is largely reduced when surrounded by seating terraces as opposed to by perimeter walls in a rectangular hall. Lacking of upper wall surfaces would dramatically reduce reflective energy directed back to the performer himself and to the others. The missing energy could, however, be enhanced by reflective energy from overhead, detached reflectors and other terrace walls in front of the stage. Computer simulations and scale model measurements are conducted considering tilting of side stage walls, form of the overhead reflector and height of the overhead reflector. The enhancement in both early support and reflective sound strength on stage is roughly 2.5 dB. Making the reflector surface highly diffusive causes slight drop in early support but increase in hall-averaged sound strength.
Relationship between cetacean presence, their prey, and oceanographic conditions at an offshore pelagic environment
Authors: Baumann-Pickering Simone , Trickey Jennifer S. , Rice Ally , Širović Ana , Renfree Josiah , Demer David A.
Published: October 2018

Large mobile predators take advantage of offshore pelagic environments that tend to be surveyed at a low temporal scale. We present results from a one-year observation of passive and active acoustics, as well as oceanographic measures, taken at a moored location 150 nmi offshore southern California in 4000 m deep pelagic waters. The passive acoustic data shows presence of delphinids and baleen, sperm, and beaked whales throughout the recording period with species-specific seasonal occurrence. Variability in small pelagics, krill, and diel vertical migrators is evident from the active acoustic data. Multiple upwelling events and associated changes in dissolved oxygen at 500 m water depth, as well as in surface waters, were also recorded over the year. We will present results on the relationships among oceanographic variability, presence of pelagic species, and top predator presence. This study will provide valuable information on ecosystem processes in meso- and epipelagic waters on a relatively small spatial scale but very fine temporal scale.
Acoustic estimation of the biodiversity of fish and invertebrates
Authors: Mouy Xavier , Cabrera De Leo Fabio , Juanes Francis , Dosso Stan E.
Published: October 2018

The increase in climate and anthropogenic stressors in the marine environment can lead to important losses in habitat for fishes and invertebrates. Consequently, monitoring marine biodiversity has become a critical task for ecologists. Traditional biodiversity measurements are costly and logistically challenging and there is an increasing need to develop new techniques that are more suitable for long-term and large-scale monitoring. The objective of this work is to assess the efficiency of active and passive acoustics to monitor the presence and diversity of fish and invertebrates. This work uses a multi-instrument platform, deployed on Ocean Networks Canada’s VENUS cabled observatory in the Strait of Georgia (British Columbia, Canada), comprised of a high-definition video camera with a pair of LED lights, a dual-frequency imaging sonar and a hydrophone. Fish and invertebrates are counted and identified using the data from the video camera and sonar. Several acoustic indices such as acoustic complexity indices and similarity sound clusters are computed from the hydrophone data. The time series of these indices estimated from the passive acoustic data are then compared to the camera and sonar recordings to assess the ability of passive acoustics alone to determine the presence and diversity of fish and invertebrates.
Continuous monitoring and classification of odontocete echolocation clicks from an ocean observatory
Authors: Urmy Samuel S. , Benoit-Bird Kelly J. , Ryan John P. , Cline Danelle E.
Published: October 2018

Passive acoustic monitoring is a valuable technique for detecting the presence and inferring the activities of odontocetes, but is often limited by power and data-storage constraints of self-contained recorders. Since July 2015, a broadband (10 Hz–128 kHz) hydrophone has been recording continuously at the Monterey Accelerated Research System (MARS), a cabled observatory in Monterey Bay, California, USA. This acoustic record is notable for its combination of duration, bandwidth, and completeness. An automated detector identified more than 200 million unique clicks in this dataset, and extracted a variety of time-domain, spectral, and cepstral features from each click. Depending on the criteria used, clustering algorithms identified 4-8 click classes consistent with those of local odontocete species, including dolphins and beaked whales. Clicking rates were highly variable, with a median of 0.2 clicks minute-1 and a mean of 165 (± 130 standard error) clicks minute-1. Echolocation activity was 1-2 orders of magnitude higher at night than during daytime, and was seasonally higher in fall and winter. Prior work has shown that mesopelagic sound-scattering layers in Monterey Bay are densest at these times of year, suggesting higher availability of prey. Continuous passive monitoring has great potential to improve our understanding of these species’ foraging ecology, especially when integrated with environmental measurements and active acoustic measurements of their prey fields.
Analysis of frontal eddies effect and horizontal refraction in Gulf of Mexico with Hybrid Coordinate Ocean Model (HYCOM)
Authors: Xiao Yao , Sabra Karim G. , Li Zhenglin
Published: October 2018

The cold and warm water carried by the eddies can significantly change the structure of the sound speed field, which is the key factor affecting long range deep-water sound propagation. Investigations of individual eddies have typically employed extensive deep bathy thermography readings. However, these procedures typically require a high density of readings throughout the oceanic region containing the eddy, requiring fairly extensive ship time and equipment. Further, results from these procedures are restricted to regions within the eddy where data were acquired. Fortunately, with the development of ocean models, it is convenient to obtain high-resolution ocean state estimates in global ocean as well as in regional ocean areas. In this presentation, we use the Hybrid Coordinate Ocean Model (HYCOM) extensively for high-resolution simulations to quantify the effects of vertical and horizontal refraction caused by a realistic ocean environment and actual bathymetry in Gulf of Mexico. For fixed source and receiver configurations, the impact of frequency, source depth in received pressure field and influence of frontal eddies on the travel time (and arrival angle) are examined. Moreover, the scenario and computational approach for a simulated long-range transmitted signal through a dynamic ocean with eddies is presented. Depth-averaged transmission loss, which computed by averaging the acoustic pressure-squared in the water over depth, is used to facilitate the observation of 3D horizontal refraction through frontal eddies.
Ultrasonic bioreactor to monitor 3D culture human engineered cartilage
Authors: Melchor Juan M. , Lopez-Ruiz Elena , Soto Juan , Jimenez Gema , Antich Cristina , Baena Jose Manuel , Perán Macarena , Rus Guillermo , Marchal Juan Antonio
Published: October 2018

Engineered cartilage tissue is one of the most promising treatments for articular cartilage pathologies. In this work, an ultrasonic bioreactor was designed to implement a non-invasive real-time monitoring of the neo-cartilage tissue formation processes through signal analysis. Polylactic acid (PLA) scaffolds were printed and seeded with human chondrocytes. Then, they were cultured in an ultrasound (US)-integrated bioreactor. The readings from the ultrasonic sensors were analyzed by numerical models of the ultrasound-tissue interaction and by a stochastic treatment to infer the extracellular matrix (ECM) evolution. To reconstruct the velocity and attenuation from the recorded signals, a genetic-algorithm based inverse problem (IP) was combined with an iterative computational propagation. The ultrasonic data were validated against evolution measurements of the in vitro 3D chondrocyte cultures assessed by proliferation and morphological observations, qualitative and quantitative biochemical parameters and gene expression analysis. The significant correlation shown between glycosaminoglycans (GAG) and collagen II (Col II) expression with the elastic damping evolution of the novo ECM (R = 0.78; p<0.001) and (R = 0.57; p<0.01), respectively, reinforces the feasibility of using ultrasound to evaluate chondrocyte functionality. Consequently, US can be used to monitor chondrocyte proliferation and ECM formation in the context of 3D cartilage engineering.
Characterizing tissue calcifications using the color Doppler ultrasound twinkling artifact
Authors: Zinck Scott A. , Simon Julianna
Published: October 2018

Rapid Doppler shifts highlight some kidney stones with a rapid change of color in ultrasound imaging in what is termed the “twinkling artifact.” While many hypotheses exist to describe the origin of twinkling, the currently accepted hypothesis is that surface microbubbles are stabilized in the crevices on the surface of the kidney stone. The objective here is to evaluate the distribution of bubbles stabilized on the kidney stone surface and to determine whether other calcified tissues display the twinkling artifact. A Verasonics® research ultrasound system with the Verasonics® L22-14 and Philips/ATL L7-4 and P4-2 transducers was used to quantify twinkling on kidney stones and in minerals deposited by osteogenic stem cells over a range of frequencies. Preliminary results on kidney stones suggest that surface roughness and chemical composition influence the magnitude of twinkling. Osteogenic stem cells were also found to twinkle when minerals were present; correlating twinkling magnitude with the quantity and distribution of mineral deposition is a topic of ongoing research. The appearance of twinkling on even small tissue calcifications indicates ultrasound is very sensitive to mineral deposition and suggests that bubbles may be byproduct of the calcification process.
Comparing resonance frequencies in muscle tissue before and after exercise induced damage
Authors: Jones Garrett , Smallwood Cameron , Feland Brent , Blotter Jonathan
Published: October 2018

There are various approaches to measuring muscle fatigue, including such simple measures as surveys for qualitative data, and measuring power output for quantitative data. Electromyography is consistently used to determine muscle fatigue. However, a quantitative measure of muscle recovery after exercise-induced damage is yet to be defined. The objective of this study is to measure the resonance frequency of a muscle group using a 3D laser vibrometer system and make a correlation with both elastography stiffness measurements, and with recovery of a muscle group based on standard muscle fatigue measurement techniques. Measurement of the resonance frequency of a muscle group has been successfully performed, and there is good reason to believe that the resonance frequency of the muscle group does shift after exercise-induced damage occurs. The main outcome of this study will determine whether the shift in resonance frequency of a muscle group can be used to track recovery after a damage protocol.
Inciting our children to turn their music down: The AYE concept
Authors: Voix Jeremie , Dumoulin Romain
Published: October 2018

According to the World Health Organization (WHO), more than 1.1 billion people are currently at risk of losing their hearing due to excessive exposure to noise. Of this, a significant proportion consists of children, youth and young adults who are exposing themselves to excessive levels of sound through various leisure activities (music players, concerts, movies at the theatre, dance clubs, etc.). To address this issue, many approaches have been developed, ranging from general awareness messages to volume limiters on personal music players. Nevertheless, it seems that, as with all dangerous behaviors, the most promising approach is a direct one in which a personalized assessment of the risk has been made and the person is made aware of the associated detrimental consequences. The present paper describes a counseling approach whereby the sound exposure is associated with an increased loss of hearing sensitivity. The proposed “Age of Your Ears (AYE)” metric is computed using the ISO 1999 multiregression model and predicts for a given age and a given sound exposure the resulting accelerated aging of the person’s hearing. Preliminary results from pilot studies and focus groups with youths will be presented together with the underlying mathematical and statistical foundations.
Urban soundscape: A case study in Taipei Dome
Authors: Chuo ChiaYuan , Tsaih Lucky S.
Published: October 2018

Taipei Dome (TD) is under construction and located in the heart of Taipei City. It is surrounded by prominent shopping district and popular cultural centers. The capacity of TD is 40,575 seats. Songshan Cultural and Creative Park is within the same block as TD and has retained the remaining green area within the block. Once it is in operation, the impact of the subsequent vehicular and crowd noise to the nearby buildings and green area is inevitable. To understand the nearby soundscape of TD, an itinerary with 8 locations were used. In-situ visual/aural observation with video recording were performed in 4 different time periods during one weekday and one weekend. A list of taxonomy of sounds was derived. While vehicular noise is the dominant sound category, natural sound such as bird chirping and crickets calling were also identified. Traffic counts were conducted. Scooters and cars were the two main vehicular types and with peak volumes during weekend evenings. Sound pressure level of each location was measured. Maximum peak sound pressure level of car noise reached as high as 109.5 dB. Mitigating expected vehicular noise and enhancing natural sound around TD should be considered by its design team.
Acoustic manipulation and actuation of bubbles in complex environments: Beyond the Bjerknes force
Authors: Baresch Diego , Garbin Valeria
Published: October 2018

Micron-sized gas bubbles are notoriously difficult to isolate, handle and remotely control. Their large buoyancy in common liquids will usually force them to rise and burst at any gas/liquid interface or remain trapped against a solid boundary until dissolution. While bubble stability issues against dissolution have found numerous practical workarounds, the challenge remains at isolating and maneuvering a single bubble in free space to, for instance, perform precise single bubble dynamics experiments with applied ultrasound or to use them as active carriers for a specific payload deliverable on demand. Here we demonstrate that single-beam acoustical tweezers [D. Baresch et al, Phys. Rev. Lett., 116, (2016)] can trap and manipulate in 3D a single bubble with the radiation pressure of helicoidal ultrasonic beams. Contrary to the situation where bubbles are trapped in the antinodes of a standing wave, the trapping vortex beam does not require oscillating volume changes of the bubble to generate a force, i.e., the trapping mechanisms cannot be explained in terms of Bjerknes forces. Viscous boundary layer effects and large bubble stability will be discussed. Opportunities for our manipulation technique to probe the high speed dynamics and rheology of particle-laden armored bubbles will also be presented [V. Poulichet et al., PNAS, 112, (2015)].
Neuronal frequency selectivity in the inferior colliculus and cochlear nucleus of the awake behaving macaque monkey
Authors: Burton Jane A. , Ramachandran Ramnarayan
Published: October 2018

Frequency selectivity relates to the ability to process complex signals and can be measured through auditory filters. Behavioral filters show broader tuning compared to cochlear and auditory nerve fiber tuning. To test whether filters evolve across the auditory pathway or if they are established in the periphery, we estimated neural filters in the cochlear nucleus (CN) and inferior colliculus (IC) and compared with simultaneously measured behavioral filters in macaques. Three macaques were trained to detect tones (signal = unit characteristic frequency (CF)) in spectrally notched maskers of varying width while single unit responses were recorded in the CN and IC. Filter shapes and bandwidths were estimated from the masked thresholds using the rounded exponential fit. Behavioral and neural filters increased in bandwidth with increasing CF. Behavioral and neural bandwidths were significantly correlated and not significantly different from each other for the CN and IC. Neural filter bandwidths were variable across units and structures, possibly reflecting heterogeneity of neuronal encoding strategies. These findings support a model in which behavioral frequency selectivity is established early in the auditory pathway. These data form the baseline for ongoing studies of macaques with noise-induced hearing loss and future studies of emerging hearing loss therapeutics.
A cross-linguistic study of phonetic correlates of metrical structure in under-documented languages
Authors: Gordon Matthew K. , Applebaum Ayla , Chacon Thiago , Martin Jack , Rose Françoise
Published: October 2018

Although languages with rhythmic stress have been extensively described and analyzed in the phonology literature, there has been little phonetic verification of the metrical structures suggested by these stress patterns. This paper presents results of a cross-linguistic study of the acoustic correlates of foot structure in several under-documented languages with morphologically complex words providing the necessary backdrop for the realization of rhythmic metrical structure. Various potential acoustic exponents of metrical structure are considered, including duration, F0, intensity, and formant frequencies. The targeted languages include Muskogean languages of the United States (Koasati, Muskogee, and Chickasaw), Circassian languages spoken primarily in Turkey and Russia (Kabardian and Adyghe), the Tukanoan language Kubeo of Brazil and Colombia, and the Arawak language Mojeño Trinitario of Bolivia. The languages differ in their foot templates (trochaic vs. iambic), the direction of their metrical parse (left-to-right vs. right-to-left), their degree of metrical rhythm, and whether they also possess lexical tone or not. Results suggest considerable diversity in the acoustic manifestations of metrical structure (including the possibility of lack of rhythmic feet even in long words) and in the relationship between the word-level metrical system and other prosodic features, including intonation and (in tonal languages) lexical tone.
Phonetic structure of Intonational prominence in 3 Dene/Athabasakn (ISO den) languages
Authors: McDonough Joyce
Published: October 2018

In this paper, we examine the prosodic structure of Y/N Q’s and focus constructions in three related Dene/Athabaskan tone languages spoken in North American: Navajo, Dene Sų́łíne, and North Slavey (Deline), known for their complex polysynthesis, representing a geographically widespread language family, from the American Southwest (Navajo), to northern Alberta (Dene Sųłine) to the arctic (North Slavey). These languages share a strikingly similar phonetic inventory and morphological structure. One interesting feature is the phonotactic structure of the morphology—the monosyllabic verb stem is the location of phonemic contrasts: outside the stem the contrasts are severely reduced, making the stems phonemically and phonetically prominent. The stems are the rightmost elements in the verbal complex and in a sentence (verb final). Navajo has been argued to lack any kind of intonational prominence, but the northern languages show more typical prominence marking. In this study we lay out the difference associated to the demarcation of boundaries and prominence: duration and the acoustic correlates of pitch accent events associated with focus and YN/Q’s and boundary marking. Data is taken from conversation games models on map tasks. Findings indicate while phonetically and morphologically similar great variety is found in the prosody.
Post-tracking range-rate estimation with up/down linear-frequency-modulated pulses
Authors: Abraham Douglas
Published: October 2018

Range-rate (RR) estimation in active sonar is most often accomplished using continuous-wave (CW) pulses. An alternative that is more suited for use with slowly moving objects in reverberation-limited conditions is presented and evaluated. As described by A. Rihaczek [Principles of High Resolution Radar, McGraw Hill, 1969], the approach entails simultaneously transmitting up- and down-sweeping linear frequency modulated pulses (LFM-U&D). The key enabler of the LFM-U&D is the complementary range-bias information relative to using a single LFM sweep type (LFM-U|D). Novel in the proposed LFM-U&D approach is the use of multiple pings after tracking to form improved range and RR estimates. Cramer-Rao lower bounds (CRLBs) on estimator variance as a function of the number of pings illustrate that LFM-U&D is a compromise between the CW and the standard LFM-U|D. Estimates of the RR of clutter tracks from the Target and Reverberation Experiment (TREX13) were used to evaluate the approach. An order of magnitude reduction in the inter-quartile range (IQR) of the RR estimate was observed for LFM-U&D relative to LFM-U|D, which allows a significant reduction in the number of false tracks. The full reduction in IQR predicted by the CRLB was seen to be limited by the effects of surface motion.
DOA estimation in heteroscedastic noise
Authors: Gerstoft Peter , Gemba Kay L. , Nannuru Santosh
Published: October 2018

The paper considers direction of arrival (DOA) estimation from long-term observations in a noisy environment. In such an environment the noise source might evolve, causing the stationary models to fail. Therefore a heteroscedastic Gaussian noise model is introduced where the variance can vary across observations and sensors. The source amplitudes are assumed independent zero-mean complex Gaussian distributed with unknown variances (i.e. the source powers), inspiring stochastic maximum likelihood DOA estimation. The DOAs of plane waves are estimated from multi-snapshot sensor array data using sparse Bayesian learning (SBL) where the noise is estimated across both sensors and snapshots. This SBL approach is more flexible and performs better than high-resolution methods since they cannot estimate the heteroscedastic noise process. An alternative to SBL is simple data normalization, whereby only the phase across the array is utilized. Simulations demonstrate that taking the heteroscedastic noise into account improves DOA estimation.
Multi-frequency sparse Bayesian learning for matched field processing in non-stationary noise
Authors: Gemba Kay L. , Nannuru Santosh , Gerstoft Peter
Published: October 2018

Using simulations and data, we localize a quiet source in the presence of an interferer. The SWellEx-96 Event S59 consists of a submerged source towed along an isobath over a 65 min duration with an interferer traversing the source track. This range independent, multi-frequency scenario includes mismatch, non-stationary noise, and operational uncertainty. Mismatch is defined as a misalignment between the actual source field observed at the array and the modeled replica vector. The noise process changes likely with time. This is modelled as a heteroscedastic Gaussian process, meaning that the noise variance is non-stationary across snapshots. Sparse Bayesian learning (SBL) has been applied previously to the matched field processing application [Gemba et al, J. Acoust. Soc. Am., 141:3411-3420, 2017]. Results demonstrate that SBL exhibits desirable robustness properties and improved localization performance when compared to the white noise constraint and Bartlett processors.
The rate of energy transport and direct measurements of group velocity
Authors: Dahl Peter H. , Dall'Osto David R.
Published: October 2018

The Intensity Vector Autonomous Recorder (IVAR) is a bottom deployed system measuring both particle velocity and pressure (combined sensor). Results using IVAR in the Sediment Characterization Experiment (SCE17) conducted off New England (spring 2017), are presented. Data originate both from ship noise involving the closest point of approach (CPA) of a large transport vessel, and experimental SCE17 signals relating to Signal Underwater Sound (SUS) MK-64 explosive sources. Several vector and scaler metrics emerge based on different combinations of second-order acoustic fields; one is the rate of energy transport (U) to be emphasized here. For the CPA data, estimates of U versus frequency represent the speed of the net transport of acoustic energy [D’Spain et al., J. Acoust. Soc. Am. 89, 1991], and additional interpretations are presented. For the SUS data, arrivals from individual modes are resolved in time-frequency analysis. Vertical intensity is shown to be much less than horizontal, and estimates of U are identified with modal group velocity with some caveats to be discussed. For example, the group velocity associated with the Airy-phase for mode-2 (frequency ~29 Hz) is U ~ 1370 m/s. This estimate emerges directly from the analysis without recourse to range divided by travel time.
Near field scattering measurements using acoustic vector sensors
Authors: Dossot Georges , Barker Jessica A. , Perez Daniel , Barton Robert
Published: October 2018

The objective of this research is to measure and characterize acoustic energy flow surrounding underwater objects in the near field condition. To accomplish this, we employ prototype acoustic vector sensors which simultaneously measure acoustic pressure and three-dimensional acoustic particle acceleration at a singular point, allowing for precise vector field measurements. In March of 2018, a test at the U.S. Navy’s Dodge Pond Test Facility examined the intensity field surrounding hollow spheres at low ka (wavenumber × radius) values. Phase differences between varying acoustic path lengths from reflected, scattered, and creeping waves result in interference patterns around the object. Various intensity processing techniques are used to reconstruct the acoustic field. Instantaneous intensity describes the time-dependent energy flux of the field and can be divided into active (real) and reactive (imaginary) components, which represent physically real elements. Time-averaged intensity shows energy transport and can be visualized in the form of acoustic streamlines.
Ambient vector field measurements in the Northwest Providence Channel
Authors: Deal Thomas J. , Custodio Derrick , Cray Benjamin
Published: October 2018

Data collected by a low-frequency acoustic vector sensor in shallow water west of the Berry Islands, Bahamas, will be presented. The frequency- and direction-dependence of the ambient noise was used to identify potential sources, such as distant shipping, wind-driven surface noise and subsurface currents. Noise sources were validated using recorded Automatic Identification System (AIS) tracks, weather observations and Acoustic Doppler Current Profiler (ADCP) measurements. A model of wind-driven surface noise that accounts for propagation effects due to range-dependent bathymetry, sound speed profiles, and surface waves will also be presented and compared to measured data.
Vector field observations near the continental slope off Big Sur, California
Authors: Smith Kevin B. , Deal Thomas J. , Leary Paul , Seda Steven , Carpenter Benjamin , Laksana Fahmi
Published: October 2018

In this work, data collected approximately 3 km off the coast of Big Sur, California, by a low frequency vector sensor system will be analyzed. Directional and temporal variations in the ambient noise field will be evaluated, and causes will be considered including flow noise due to currents, surface (wind) noise, distant shipping, and marine mammals. Bearing estimation results for shipping will be compared with AIS tracks recorded during the period of deployment. Local sound speed measurements and bathymetry in the vicinity of the deployment area will be used as inputs to a two-dimensional propagation model that properly invokes reciprocity of the acoustic vector field. Surface wave spectra collected by a nearby buoy will be used to generate rough surface realizations in order to evaluate the impact of these perturbations on low frequency vector field structure. These results will be combined with acoustic data observations in attempts to determine the impact of propagation on the structure of the field. Such an approach may allow us to infer acoustic source levels of AIS traffic off the coast.