bluuebunny/crossref_metadata_2025 huggingface dataset:
SAFE Credit Union Performing Arts Center audio enhancement to support architecture
Authors: Manley David , Hopkins Jonathan , Grant Anat , Krumhansl James
Published: November 2023

Opened in 1976 and without a major renovation since, the 98,000-sf SAFE Credit Union Performing Arts Center was in dire need of transformation. The building’s aging infrastructure needed a comprehensive modernization to meet accessibility requirements, the escalating requirements of contemporary performance, and to present a new face to the public as the premier cultural institution in the state capital. The existing theater’s acoustics represented a challenge to effectively accommodate the wide range of performance types including Broadway roadshows, the Sacramento Choral Society, and the Sacramento Philharmonic and Opera. Major renovations work included a complete exterior renovation; new mechanical, plumbing, electrical, and theatrical systems; and substantial updates to the interior finishes throughout the building. Providing an accessible venue to all patrons and performers was the primary goal of the project. Significant modifications to the external and internal circulation included removal of the entire audience chamber floor and new seating and aisle ways throughout. An electro-acoustic enhancement system was designed to provide an acoustically tunable audience chamber and electronic shell on stage to meet all the needs of the resident companies. Design and implementation of the electro-acoustic enhancement system will be discussed, including challenges of performer buy-in and audio orchestra shell integration.
Examining environmental conditions that influence long-term Antarctic blue whale migration patterns in the Southern Hemisphere using an 18-year passive acoustic dataset
Authors: Truong Gary , Rogers Tracey L.
Published: November 2023

Antarctic blue whales (Balaenoptera musculus intermedia) are difficult to study due to the low numbers and cryptic behaviour. The largest subspecies of blue whale migrates from Antarctic feeding areas to temperate and tropical breeding grounds every year. Their use of these remote areas makes it difficult to detect them using visual survey methods. However, blue whales are vocal animals and sing throughout the year especially during their annual migration. By using passive acoustic monitoring, we can study the long-term migration patterns of Antarctic blue whales across the Southern Hemisphere. Using an 18-year passive acoustic dataset from the CTBTO, we examined the migration patterns of Antarctic blue whales across four different locations spread across all three major ocean basins. We modelled blue whale acoustic detections with environmental variables including El Niño Southern Oscillation, the Southern Annular Mode, and yearly Antarctic sea-ice extent. We also examined krill abundance estimates from Krill Base in our models. We found that the whale call detections at the four sites were correlated with different variables. The variables were also correlated with various degrees of lag. Our study provides evidence that these whales vary their migration patterns from year-to-year with respect to changing oceanic, and climatic conditions.
Suspected evening fish chorusing sounds detected in deep waters off Kauai, Hawaii
Authors: Martin Stephen W. , Alongi Gabriela C. , Helble Tyler A. , Martin Cameron R. , Matsuyama Brian , Henderson Erin E.
Published: November 2023

Noise analyses are crucial to understanding passive acoustic monitoring for marine mammals and their behavioral responses to natural and anthropogenic noises. Suspected biological sounds in the ambient noise data from hydrophones at the Pacific Missile Range Facility (PMRF), Kauai, Hawaii have been found. The sounds are suspected to be chorusing associated with the Deep Scattering Layer (DSL) upward daily vertical migration given they peak around 2 hours after sunset. They have been observed occurring daily including a period in January 2017 when high ambient noise levels during a storm was associated with baleen whale cessation of calling. The sounds occur from 1.4 to 1.8 kHz with the peak near 1650 Hz. They are detectable on multiple broadband hydrophones (21 to 68 km offshore) in deep water (1.5 to 4.7 km), suggesting a large spatial extent. The maximum spectrum level in the 1.6 kHz 1/3rd octave band observed to date was 71 dB re 1 μPa2/Hz. Individual sounds have not been identified to date given the geometries involved and the large spatial extent sensed using deep water hydrophones. These results have similarities to related chorusing research which has suggested a potential link with Myctophidae fishes.
Voices from the deep: Odontocete occurrence patterns relative to oceanographic conditions in the northern California Current System
Authors: Garcia Marissa , Cohen Rebecca , Risien Craig , Barlow Dawn , Derville Solène , Fewings Melanie , Torres Leigh , Klinck Holger
Published: November 2023

Odontocetes play an important ecological role as apex predators in the northern California Current System (CCS), which is characterized by seasonal rises in primary productivity fueled by wind-driven upwelling of cold nutrient-rich water. This productivity sustains higher trophic-level prey optimal for deep-diving odontocetes including beaked and sperm whales. Due to the cryptic ecology of these whales, there are few systematic studies of their occurrence across seasons in northern CCS waters. The Holistic Assessment of Living marine resources off Oregon (HALO) Project—a collaboration between Oregon State University and Cornell University—addresses this gap via quarterly vessel-based visual surveys and year-round passive acoustic monitoring (PAM). Here, we detect and classify species-specific odontocete acoustic signals using long-term spectral averages, automated click detection, and unsupervised clustering of semi-continuous PAM data from 10/2021 to 12/2022. Site-specific occurrence of beaked and sperm whales is revealed on hourly to seasonal temporal scales at three recording sites along a depth gradient spanning the continental slope (300 and 630 m water depth) and abyssal plain (2860 m). By relating odontocete detections to dynamic oceanographic conditions from nearby profiling moorings, we identify likely drivers of prey availability influencing predator distribution. These results will inform conservation efforts of cryptic odontocetes in the face of rapid environmental change.
Interpreting phase shifts of basin-scale arrivals observed in the North Pacific
Authors: Dall'Osto David R. , Gemba Kay L.
Published: November 2023

The 75 Hz Kauai Beacon is well situated for observing the North Pacific Ocean acoustically. Somewhat conveniently, three ocean observing networks, with acoustic receivers located within the deep sound channel: two observatories 4 mm to the East (RCO: Regional Cabled Observatory and MARS: Monterey Accelerated Research System), and the International Monitoring Station at Wake Island 3.5mm to the West. During April–June of 2023, the Beacon transmitted a 37.5 Hz bandwidth m-sequence signal several times a day every 4 days. Upon processing, a persistent arrival structure is identified, which for which each arrival exhibits a unique, yet relatively steady phase over the course of a 20-min transmission. Leveraging acoustic propagation models to better understand the effect of the fluctuating ocean environment, we address the stability of the arrivals over the 20-min transmissions, from hour to hour, and over the course of the 3-month study. This includes examination of potential causes for the slow-phase shifts observed at all of the stations, and how it relates to Doppler. This talk concludes with a discussion on the future utility and research topics of interest, including long-range geo-positioning (underwater GPS), communications, thermometry, and tomography.
Detecting the Kauai source beacon with ocean observatories innitiative hydrophones
Authors: Ragland John , Durofchalk Nicholas C. , Gemba Kay L. , Abadi Shima
Published: November 2023

In March of 2023, a sound source off the coast of Kauai began regularly transmitting a 75 Hz signal into the ocean, six times a day, every fourth day. The regular transmission of this signal allows for the long-term measurements of ocean basin scale temperature changes using the technique of acoustic tomography, as well as further investigations of long-distance acoustic propagation. The Ocean Observatory Initiative (OOI) has, as part of its suite of oceanographic sensors, 11 hydrophones that are continually recording ambient sound. These hydrophones are in various diverse environments in the north-east pacific including bottom mounted in shallow environments, deep environments, on top of seamounts, and moored at 200 m below the ocean surface. In this talk, we present preliminary results of acoustic propagation modeling and data analysis towards receiving the Kauai signal with the OOI hydrophones. The diverse environments of the hydrophones allow us to investigate how different levels of ambient sound and environmental factors, such as proximity to the sound channel affect the ability to detect a positive reception of the Kauai source across the ocean basin. [Work supported by ONR.]
SMART submarine cable technology can facilitate acoustics on the global scale
Authors: Howe Bruce
Published: November 2023

The submarine cable industry is beginning to share their infrastructure for ocean observing. Science Monitoring And Reliable Telecommunications (SMART) Subsea Cables is working to integrate temperature, pressure, and seismic acceleration sensors into commercial cables (∼70 km spacing) to support climate monitoring and disaster risk reduction on the global scale. The seismic and pressure sensors are expected to have sensitivity at low acoustic frequencies, (e.g., <50 Hz and <5 Hz, respectively); future systems could include hydrophones and other sensors. Further, telecom rated branching cables supporting multipurpose “nodes” are becoming a reality (per existing dedicated science cable systems). These can support low frequency transceivers and autonomous undersea vehicles (AUVs). With cabled power, these would be part of the fixed/mobile acoustic tomography system measuring ocean heat content and more generally for transporting energy, data, and acquiring multidisciplinary data throughout a large volume of the ocean. A 3700 km SMART ring system in Portugal will be ready in 2026 and one connecting Vanuatu and New Caledonia is starting. Others in planning stages that could include these concepts are: Far North Fiber connecting Norway/Finland/Ireland with Japan, the NSF proposed SMART cable connecting New Zealand with Antarctica, New Zealand-Chatham Islands, and Lisbon-Egypt through the Mediterranean.
Tangent linear approximations for split-step Padé solutions of the parabolic-equation method in two dimensions
Authors: Lee Brandon M. , Dowling David R.
Published: November 2023

The parabolic-equation (PE) method is a popular technique in underwater acoustics for obtaining 2D and 3D acoustic-field predictions in spatially-dependent environments. Tangent linear models for these PE solutions relate perturbations in the environmental properties (inputs) to corresponding changes in the acoustic field-solutions (outputs), enabling efficient schemes for approximately transferring parametric uncertainties through to acoustic-field uncertainty or computing the sensitivity of the acoustic-field to these parameters for adjoint-based acoustic inversions. Previously, first-order and higher-order tangent linear models have been developed with respective square-root operator splitting schemes for use with finite-difference and split-step Fourier PE solutions. This presentation describes the findings of an investigation into using these previously developed tangent linear models with the popular split-step Padé method in 2D problems. Additionally, two new tangent linear models are proposed based on directly perturbing: (1) the combined exponential operator in the analytical solution of the one-way wave equation and (2) the split-step Padé solution itself. The forward errors of these tangent linear models are compared analytically and across a variety of computational examples. The numerical stability of each approach is also important and of interest. Finally, the computational savings (if any) from using each approximation over the original split-step Padé model are discussed.
Acoustic radiation characteristics according to the vibration area of OLED panel speakers
Authors: Park Hyungwoo , Lee Sungtea , Park Kwanho
Published: November 2023

Previous studies have introduced the potential of flat OLED panels to be utilized as multiple-channel speakers. Subsequent research has also focused on improving sound quality and implementing multi-channel audio system in OLED TV. For personal displays using OLED panels find diverse applications, offering comfortable and accessible viewing for OTT services with top-notch video and audio quality. Moreover, they excel in delivering crucial audio information during various gaming experiences. In this study, we present a film-based Cinematic Sound OLED (CSO) technology, directly vibrating a single flat OLED panel, which extends the vibrational area compared to previous studies and can reproduce two or more independent sounds. In particular, the proposed method transmits information by generating sound directly on the screen. This method is as sophisticated, accurate, and realistic as the method using headphones. Headphones or earphones generate sound close to the human auditory system, potentially harming auditory health. However, the proposed method aligns the focus of the display and sound, maintaining a certain distance from the user's auditory system. In this paper introduced the advantages of the proposing method and discuss a personal high-performance display device and an appropriate advanced audio generation method.
Head-related transfer functions upsampling with physics-informed spherical convolutional neural network
Authors: Chen Xingyu , ma fei , Samarasinghe Prasanga N.
Published: November 2023

Head-related transfer functions (HRTFs) play a crucial role in virtual acoustics and spatial audio applications. However, obtaining personalized, high-resolution HRTFs remains challenging due to the time-consuming and expensive measurements. Recently, deep learning-based methods have shown promise in predicting high-resolution HRTFs from sparse measurements. Nevertheless, most of these methods often treat HRTF upsampling as an image super-resolution task, which overlooks critical spatial information and acoustic principles, leading to overfitting on datasets. This paper proposes a physics-informed spherical convolutional neural network for HRTF upsampling. First, spherical convolutional layers are used to capture spatial features on the sphere, allowing efficient handling of spherical sampled HRTF data. Second, in the upsampling process, the proposed method incorporates the Helmholtz equation as a constraint, adhering tothe physics of the acoustic system. This method ensures the generation of physically feasible HRTF interpolations, thus promoting better generalization.
Reassessing the anomalous low frequencies in the Japanese koto
Authors: Coaldrake Kimi
Published: November 2023

A previous study reported on a finite element model of an indigenous Japanese 13-stringed zither (the koto) based on a CT scan. Frequencies above 100 Hz were relatively easy to account for, while those below 100 Hz were more problematic. Low frequencies have also been reported for the piano, another zither of similar length. The model has now been updated in a range of critical areas, including damping. The updates have resulted in a more precise resolution of the model. It allows us to reassess the anomalous low frequencies to determine if they have other rational explanations. This work continues to expand knowledge of the koto’s complex resonances and has broader applications for understanding the characteristic sounds of other wooden indigenous musical instruments.
Optimized muffler design and its performance evaluation to environmental noise reduction on classrooms
Authors: Arifianto Dhany , Firda Jamiatul , Asyraf Muhammad A.
Published: November 2023

Generators powered by diesel engines are widely used as a backup source of electrical energy. However, the generator produces very high noise, which is around 73–110 dBA. In this study, we designed a muffler and optimized to the highest possible noise reduction. We constructed and installed the designed muffler to evaluate the performance an absorptive muffler on the exhaust pipe of the simulated muffler with the installed one. We measured the sound pressure level (SPL) at the source of exhaust gas noise before the proposed muffler installed and after installation, including inside the surrounding classrooms. A survey was also conducted to determine the annoyance response of the teachers and the students. The results show that the presence of an absorptive muffler can reduce noise by 10 dBA and attenuate more at high frequencies (<500–16000 > 500–16000 Hz) at the source of the noise and also in the surrounding environment. The annoyance rating for generator exhaust noise is moderate to very disturbing for listeners who are outside the room and moderate for listeners positions in the room.
Topology optimization of array of split-ring resonators in two-dimensional acoustic waveguide for low-frequency transmission problems
Authors: Lam Wai Kit , Krynkin Anton , Tang Shiu Keung
Published: November 2023

This work focuses on the topology optimization of an array of split-ring resonators to achieve nearly zero transmission in the low-frequency regime ranging from 500 Hz to 1000 Hz in 2D waveguide, under the condition of normal-incident plane wave and based on a homogenization scheme known as the Effective Medium Approach (EMA). The EMA transforms each individual resonator defined by its outer radius (rout), neck thickness (h), and the slit width (d), into a homogenous medium characterized by frequency-dependent physical parameters. The transmission coefficient (Tcoeff) of the array can thus be easily evaluated without relying on computationally expensive Finite Element (FE) software. Two optimization algorithms, namely “Sequential Quadratic Programming (SQP)” and “Genetic Algorithm (GA),” have been implemented to the abovementioned topological parameters with sum of Tcoeff being the objective function to minimize. Accuracy of the results has also been validated using software COMSOL Multiphysics® and the satisfactory level of accuracy has proven this approach to be a more efficient and time-saving method to conduct topology optimization of split-ring resonators in low-frequency regime. Moreover, it is noteworthy that the optimized dimensions of resonators are over 20 times smaller than the wavelength in the low frequency range where almost-zero transmission is achieved.
A risk-based approach to precinct planning
Authors: Jenkin Lance , Scully Rick A.
Published: November 2023

As urban populations increase more people being affected by noise. Industrial precincts are a key component of the economy, but they are placed near existing resident. Planning is an important tool to manage the noise exposure from these areas. This paper describes the method we developed to help with deciding where noisy activities, and the amount of mitigation required, to reduce the risk of annoyance from the precinct. Our method is based on modeling the impact from a grid of sources overlayed on the precinct boundary. The transfer functions for each source to all sensitive receiver is calculated using a standard noise propagation model. An optimization algorithm is used to fairly calculate the maximum sound power for each grid point without exceeding the noise management levels. Risk maps are created using contours based on standard industrial sound power densities to define 3 zones: the central, intermediate, and interface. The risk maps are a useful tool for planners for deciding where to locate projects and the amount of mitigation required.
Sources of anthropogenic sound in the Svalbard environment
Authors: Piechowicz Janusz , Wiciak Jerzy , Mlynarczyk Dorota , Malecki Pawel
Published: November 2023

Svalbard is one of the few sparsely populated areas of the Earth. Settlement is not favored by the climate, permafrost and difficult weather conditions. But even here, settlements inhabited by people are developing. And when there are people, there is also noise. In our research, we addressed the issue of identifying sources of noise generated in human settlements; traffic noise, industrial noise and tourist noise. We have carried out a number of measurement sessions to determine the sound power of individual sources in the city, as well as the history of temporal changes in A-weighted sound levels in 24-hour periods in Longyearbyen, the capital of Svalbard.
Battery energy storage systems environmental noise emission
Authors: Eriksson Linnea , Lai Zhang
Published: November 2023

The use of Battery Energy Storage Systems (BESS) in the electricity grid is rapidly growing due to its ability to bridge the gap between times of energy needs and when certain renewable sources are not generating. The use of battery storage helps the grid to remain stable due to its ability to respond quickly to changes in energy demand. Grid-scale battery storage has the potential to significantly assist in the renewable energy transition. Noise has emerged as a key environmental impact challenge in the development of BESS. But why? In our work with BESS, the noise is commonly associated with the battery and inverter modules’ heating and cooling systems, with the use of fans and compressors being the main emitters. However, the noise levels emitted are highly variable and depend on several factors, including operating conditions, ambient temperatures, and speed drives. We will explore the noise emissions of BESS, and key challenges like: —pathways for mitigating noise, including discussion of options at different project stages, ranging from site selection to commissioning. —challenges in accurate noise emission modeling —explore lessons learnt from a project from the design stage to post construction commissioning testing. Including the noise modeling predictions and their accuracy.
Acoustic cavitation detection in biomedical and underwater systems
Authors: Elliott Jacob , Rokni Eric , Trzcinski Paul , Krane Michael , Harris Jeff , Simon Julianna
Published: November 2023

In the past decade, significant progress has been made in detecting and localizing cavitation for treatment monitoring in biomedical acoustics. Here, we compare passive cavitation imaging (PCI) and passive cavitation detection (PCD) during histotripsy in tissue-mimicking polyacrylamide (PA) hydrogels; PCI and bubble Doppler ultrasound are also used to evaluate flow-induced cavitation in a water tunnel. A Philips/ATL L7-4 transducer driven with a research ultrasound system was used for both PCI and Doppler imaging; a Sonic Concepts Y-107 transducer was used for PCD. PA hydrogels were treated with 1.5 MHz focused ultrasound (10-ms pulses with p + = 127 MPa/p− = 35 MPa repeated at 1-Hz for 60 s). In the 12-in. water tunnel, cavitation on a 1-in. diameter steel cylinder was imaged through a 0.5-inch-thick acrylic window while flow increased from 30–35 ft/s. High-speed cameras were also used in both experiments. In PA hydrogels, cavitation was observed with both PCI and PCD, although signal trends differed over the treatment. In the water tunnel, both PCI and Doppler ultrasound detected and localized cavitation events such as the horseshoe vortex, with measured amplitudes increasing with flow speed. These results show that cavitation imaging can be applied to multiple areas of acoustics. [Tissue work supported by NIHR01EB032860].
Bioeffects of microbubbles in tissue engineering: Modeling collapsing jets and microstreaming
Authors: Sarkar Kausik
Published: November 2023

Ultrasound contrast agents are micron-sized bubbles coated with lipids/proteins to stabilize them in the bloodstream. Apart from enhancing the contrast of the image, they have been implicated in numerous harmful and beneficial bioeffects. I will present an overview of our research emphasizing recent efforts on microbubbles-based non-invasive pressure estimation and ultrasound-assisted bone and cartilage tissue engineering in 3D printed scaffolds. Low-intensity pulsed ultrasound (LIPUS) in conjunction with microbubbles has been shown in our lab to facilitate bone and cartilage formation from mesenchymal stem cells. We will discuss nonlinear shape oscillations of microbubbles and acoustic microstreaming that are responsible for such bioeffects. We studied them using boundary element (BEM) simulation and perturbative analysis of an encapsulated microbubble near a vessel wall. For the BEM solution, the coating of the microbubble is modeled as a viscoelastic interface using an in-house developed strain-softening model (exponential elasticity model). The influence of the shell model on the stability of the numerical simulation during the microbubble jet formation has been investigated. The effects of ultrasound excitation parameters and mechanical properties of the coating, i.e., shell viscosity and elasticity, on the bubble behaviors and the velocity and pressure in the surrounding fluid, have been studied.
Preliminary study to scale up microbubble generation with acoustic wave
Authors: Jung Minuk , Kim Joseph (Yeo Cheon) , Bournival Ghislain , Ata Seher
Published: November 2023

This research focuses on the utilization of acoustic wave to control the generation of microbubbles from a capillary tube, aiming for mass production with porous media. Initially. ultrasonic standing wave is employed to generate small-size microbubble since high amplitude is required for the pipette with smaller pore size which has high resistance. However, for large bubble generation, secondary acoustic radiation force between bubbles is increased and induces bubble coalescence. Pulsing wave can reduce the force strength by reducing wave cycles (apparent frequency) and increasing the distance between bubbles by controlling bubble generation frequency. Finally, maximum bubble generation frequency is calculated at each bubble size based on calculation of limiting factors such as gas permeability and secondary acoustic radiation force. The research will contribute to generate wide size range of multiple bubbles in aqueous solution and set up its limitation regarding bubble generation frequency through theoretical calculation. The data will be utilized for multiple bubble generation with porous media.
Potential of focusing retroreflectors as passive acoustic beacons for flash sonar
Authors: Cabrera Densil , Holmes Jonothan , Hasegawa Yoshimi , Lu Shuai , Sun Huiyuan , Jin Craig
Published: November 2023

Human echolocation, in the form of flash sonar, can support spatial awareness and navigation for vision-impaired people. This paper examines the potential of acoustic focusing retroreflectors to support echolocation within an area. Parabolic dihedra and trihedra, along with other variants of focusing retroreflectors, return much stronger reflections to an arbitrarily located source than equivalent flat surfaces. A head-and-torso simulator was used to quantify the oral-binaural reflected energy for various surfaces, including physical focusing retroreflectors. The effect of focusing is most advantageous in relatively close-range scenarios (within a few metres). Suggested designs and application scenarios are presented.
Frequency dependent emotional responses to sound: A cross-modal analysis of electroencephalogram band power and emotion perception
Authors: Kumar Manish , Abhayapala Thushara , Samarasinghe Prasanga N.
Published: November 2023

Enabling machines to comprehend human emotions serves as the motivating factor for our research. This effort significantly contributes to advancing emotion recognition and human-computer interaction. Our study explores the fundamental associations between emotional responses and auditory characteristics, with a primary focus on frequency. To achieve this, we conducted a two-stage perception test, aiming to identify the interplay between EEG band power and dominant emotion class as a function of frequency. Musical notes, ranging between 110 Hz and 973 Hz, served as our stimuli. During the first stage, we collected participants' EEG data, categorized it into distinct energy bands (Alpha (α), Beta (β), Delta (δ), Theta (θ), and Gamma (γ)), and analyzed band power and ratios. In the subsequent stage, we had participants evaluate their emotional responses to each stimulus. Our results from this two-stage perception test suggest that an increased tangent of the α / β band power ratio corresponds to Low-Arousal emotions, while a diminishing tangent correlates with High-Arousal emotions. Furthermore, we observed a crossover point for four primary emotions within the 417–440 Hz frequency range. This finding supports the hypothesis that the 432–440 Hz range is emotionally neutral.
Lightweight soundproofing meta-panel for two separate broadband noises
Authors: Kim Jiwan , Jeon Wonju
Published: November 2023

We propose a lightweight soundproofing meta-panel, with a multi-scale lattice structure sandwiched between thin membranes, effectively suppressing two separate broadband noises. By adjusting the geometrical parameters, the meta-panel is designed to induce negative effective mass density and negative effective bulk modulus for two distinct target frequency bands: 100–500 Hz and 1000–1500 Hz, thereby achieving high transmission loss that outperforms the mass density law. A meta-panel sample is fabricated via 3D printing technology and we evaluate its sound insulation performance by measuring transmission loss and insertion loss in an impedance tube and an anechoic chamber. Experimental measurements show that the meta-panel can exhibit excellent insulation performance while being significantly lighter in weight (about 5%) compared to a steel plate, and furthermore, it effectively suppresses low-frequency road noise and high-frequency motor noise from an actual electric car.
Exploring pulse mitigation in heterogeneous granular metamaterials
Authors: Espinosa Cuartas Marcos , Calius Emilio , Hall Andrew , Dodd George , Das Raj
Published: November 2023

Recognizing the need for effective control of vibration and sound propagation in various industries, this study investigates the potential of designing heterogeneous granular networks for vibroacoustic transmission mitigation. It introduces new models of granular systems: decorated, stepped, and tapered 2-level branching structures. The research assesses changes in particle size (5–10 mm radii) and material properties (density and Young's Modulus) to create finely-tuned composites that significantly modulate pulse waves. The discrete element method predicts wave propagation in these granular metamaterials, comparing monodispersed chains, conventional chain networks, and the proposed heterogeneous structures. Their pulse diffusion capacity is evaluated, showing how collective responses can be adjusted by altering physical parameters like particle size and composition. Preliminary findings underscore the utility of these configurations in advancing the development of elastic and acoustic metamaterials, demonstrating a peak amplitude reduction more than five times greater than an equivalent monomer system. With versatility across a wide frequency range, these metamaterials could pioneer a new direction in impact mitigation.
Identification training adapted to the learner’s vowel space aids in improving native Japanese speakers’ pronunciation of American English vowels
Authors: Martens William , Lambacher Stephen
Published: November 2023

Native speakers of Japanese learning English as a foreign language often have difficulty pronouncing certain American English (AE) vowels, such as the mid vowels /ae/, /ɑ/, / ^/, /ɔ/, and /ɚ/, which typically are assimilated to native vowel categories. It was shown that vowel identification training which was adapted to the learner’s vowel space could aid in improving the native Japanese speakers’ pronunciation of a set of 12 AE vowels that included the 5 more difficult mid vowels. Estimates of the vocal-tract length (VTL) for 53 learners were based upon the central tendency and range of the four lowest formant frequencies observed in their recordings of five short statements in the Japanese language. Having thus characterized the individual vowel spaces of 53 learners, 33 were placed in a “longer-VTL” group while the remaining 20 were placed in a “shorter-VTL” group. Those in the “longer-VTL” group were given periodic identification training using examples of 12 American English monophthongs in a consonant-vowel-consonant (CVC) context that sounded as if a male AE speaker with similar VTL had uttered them. The “shorter-VTL” learners heard training examples that sounded as if the CVCs were uttered by a female AE speaker with similarly short VTL.
Modeling reduced speech using a simulated vocal tract and overlapping acoustic events
Authors: Schnoor Tyler T. , Story Brad H. , Tucker Benjamin V.
Published: November 2023

Reduced utterances are characterized by the alteration or deletion of segments (i.e., syllables, words) and often occur in spontaneous or casual speech styles. These reductions are common in everyday communication and are generally understood given sufficient context. However, modeling reduced speech is not trivial, as the effects of context, articulatory limitations, idiosyncrasies, and speech rate need to be considered in order to approximate acoustic observations of reduction. We utilize a speech production model which modulates a simulated vocal tract according to acoustic events organized along a time axis. The present study focuses on validating its capacity for modeling reduced speech. Evidence of its effectiveness is provided by way of synthetic example utterances, each accompanied by a description of the steps taken to synthesize the utterance and acoustic comparison to an unreduced equivalent. Word-medial consonant reductions will be studied first before proceeding to massive reductions where entire syllables and words are affected. We iteratively synthesize reduced utterances until they are evaluated through informal listening to be comparable to real acoustic observations. The results of this study are discussed as validation of the idea that acoustic events can be arranged to model reductions.
Classification of Chubu-region dialects using random forest
Authors: Hattori Kota , Kishie Shinsuke
Published: November 2023

The present study investigated how Japanese dialects in Chubu region are classified using random forest (RF) and an adaptive synthetic (ADASYN) sampling approach. We obtained the written-format pronunciations of 22 words from 884 Japanese speakers (average age = 71.1) who had been residing in their birthplaces. We calculated phonetic distance (ALINE distance) between the dialectal and standard Japanese pronunciations, and ran RF models with 1,000 bootstrap samples. The results of the RF models (ROC = 0.953, F1 = 0.68) demonstrated that speakers with a predicted probability greater than 50 percent (n = 415) were generally located in their residing prefectures, suggesting that each prefecture has its own dialect. Speakers with a predicted probability less than 50 percent were located in both their residing prefectures and the vicinities of the prefectures, particularly those in Aichi, Gifu, Shizuoka, Nagano, Gunma, and Niigata prefectures, suggesting that the speakers in the areas share some characteristics of the prefectural dialects. This potentially led to the poor predictions of the speakers. The expansion of these prefectural dialects seems to be limited by the Japanese Alps; dialects spoken on the eastern and western side of the mountain range are generally widespread only in the area, respectively.
Does language matter in oral diadochokinesis (DDK) performances?
Authors: Kim Yunjung , Berry Jeffrey J. , Lee Seung Jin
Published: November 2023

Oral diadochokinesis (DDK) typically refers to rapid repetitions of monosyllables (e.g., /pʌ/, /tʌ/, /kʌ/) or multisyllables (e.g., /pʌtʌkʌ/). DDK has been frequently included in studies of motor development and disorders and its use has increased over the past decade. One unanswered question in using DDK for investigation of speech motor control is whether the studied language serves as an important factor in DDK performances. Despite the general agreement that DDK performance (mostly DDK rates) is little affected by a speaker’s native language, few data exist on language- or dialect-specific effects on DDK, which may be explained by factors such as speaking rate and rhythmic pattern of the languages. In this study, we compare DDK performances in two languages, American English (AE) and Korean, which were chosen primarily because of the difference in their rhythmic patterns (stressed-timed versus syllable-timed). A total of 80 young adults (40 AE-, 40 Korean-speakers) performed both mono- and multi-syllable repetitions and analysis was limited to the first 5 seconds of each performance. We will present data on several aspects of DDK performance focusing on prosodic patterns (syllable and intersyllable pause durations, intensity, and F0 across syllables) in addition to average DDK rates.
“Do I sound happy?” Acoustic characteristics of affective prosody in older adults
Authors: Oh Chorong , Morris Richard J. , Wang Xianhui
Published: November 2023

It is known that older adults have difficulty comprehending affective prosody. However, it is unclear how well they manipulate affective prosody to express emotion. Five older adults were recorded when they completed three speech tasks: (1) Talking about happy and sad life events; (2) Describing the Refused Umbrella pictures; (3) Explaining how to make a peanut butter and jelly sandwich. Two independent investigators listened to the recordings and parsed them into utterances considering pauses and connectivity. Afterwards, the investigators identified the primary emotion (i.e., happy, sad, neutral) in each utterance. The recordings were acoustically analyzed using Pratt for rate, pitch, and amplitude measures. The rate measures included speech and articulation rates and the pitch/amplitude measures contained initial, final, minimum, maximum f0/dB and the difference between the maximum and minimum f0/dB. Multivariate ANOVAs with Tukey post-hoc test were conducted to analyze the acoustic data. Among the acoustic measures, all rate and pitch measures were significantly different across the three emotions. However, none of the amplitude measures differed significantly. Research on production of affective prosody in healthy older adults has been scarce and this study may serve as a catalyst for further exploration in this area.
Bubble pulse arrival time calculations to determine SUS charge detonation depths
Authors: Green Haley H. , Ferguson Andrew , Johnston Sydney , Miller James H. , Potty Gopu R. , Dall'Osto David R.
Published: November 2023

As part of the New England Seamount Acoustics (NESMA) project in 2023, experiments were conducted over the Atlantis II Seamount. A total of 216 Signal Underwater Sound (SUS) broadband explosives (150 1.1 oz and 66 1.8 lb net explosive weight) were deployed at multiple locations and two different design depths around the seamount. An acoustic recorder (SoundTrap ST4300), with four hydrophone channels of varying sensitivities, was deployed during each of the SUS events to record the signals generated by the explosives. The recorded signals include arrivals corresponding to the shock wave, subsequent bubble pulses and reflections from the sea surface and sea floor. The time between the first arrival and the bubble pulse was used to calculate the depth at which each SUS charge detonated. The resulting SUS detonation depths from the bubble pulse calculation were compared with depths obtained from surface and bottom reflections to assess the accuracy of the bubble pulse method. A comparison of the results from the two methods shows that using the bubble pulse interval to calculate the SUS detonation depth is reasonable and can be used in propagation models. [Work supported by Office of Naval Research Code 322OA and TFO.]
Aural based scene understanding for sonar applications
Authors: Brown Daniel C. , Cowen Benjamin
Published: November 2023

Acoustic returns scattered from either surfaces or objects are typically interpreted using image processing techniques such as beamforming and computer vision models such as convolutional neural networks. However, image representations can be burdensome to generate, creating delayed responses in real-time scenarios, and difficult to parse from the scene-understanding perspective. This work investigates direct exploitation of the information content from streaming, near-raw sonar time series data for the purpose of scene characterization. Summary statistics drawn from the sonar performance estimation community and communities that study aural-based perception are used to identify scene characteristics such as flat sand, ripples, gravel beds, or sea grass, in side-looking synthetic aperture sonar (SAS) data. An empirical multi-class classification study is presented that explores the performance of seafloor characterization methods on time series versus imagery.
A study on the optimal configuration of absorbing materials of multi-layered silencers for maximizing transmission loss
Authors: Kang Dongheon , Yang Haesang , Seong Woojae
Published: November 2023

This study focuses on the optimal configuration of absorbing materials of multi-layered silencers applied to seawater pipelines. Absorbing materials in silencers are made of poroelastic material, and acoustic wave propagation is analyzed using the Biot-Allard Model. Acoustic transmission loss is computed numerically using COMSOL Multiphysics. It is observed that among various standard polyurethane materials, those with lower density exhibit higher acoustic transmission loss. Finally, optimization is carried out with the objective function of maximizing the transmission loss at target frequencies. Low transmission loss values at specific frequencies of one-layer silencers can be meaningfully increased by optimizing the sequence of various standard polyurethane materials.
Coherent combination of perpendicular synthetic aperture sonar passes
Authors: Dalton Kyle S. , Brown Daniel C. , Blanford Thomas E.
Published: November 2023

Many downward-looking synthetic aperture sonar (SAS) systems form a synthetic aperture in the direction of travel (along-track) and a real aperture in the perpendicular direction (cross-track). At lower frequencies and longer ranges, the difference between the synthetic aperture resolution and real aperture resolution may become significant. Images created with such a spatially-varying resolution may provide an inaccurate depiction of important seafloor features or objects of interest. Combining two perpendicular SAS passes into one “effective” pass provides a synthetic aperture in two orthogonal directions, which should enable the region where the two passes overlap to be imaged with a spatially-consistent resolution. The difficulty in this “multi-pass coherent fusion” (MPCF) comes in quantifying and accounting for all of the sources of error that occur when forming a synthetic aperture. This presentation will outline current work towards the coherent combination of perpendicular SAS passes. We will examine factors that impact the coherence between passes and show how this work relates to existing research in repeat-pass SAS, image co-registration, and SAS micronavigation. Imagery and results from both modeled data and field data will be presented. Finally, future work and applications to automatic target recognition will be discussed.
Arnoux’s beaked whales acoustically misidentified as Type C killer whales in Prydz Bay, Antarctica
Authors: Chambers Lucinda E. , McPhee-Frew Jane , Rogers Tracey L.
Published: November 2023

The Southern Ocean is home to five ecotypes of killer whale, which differ in diet, morphology, behaviour, and vocal repertoire. Recently, fish-eating Type C killer whales were reported in Prydz Bay, Antarctica from sounds recorded in hydrophone data collected in March 2017, on the basis that these sounds bore similarities to acoustic behaviour of Icelandic fish-eating killer whales. Here we re-examine the structure of the sounds identified as Prydz Bay Type C killer whales and we identify the calls to be those of the Arnoux’s beaked whale. The whistles are more structurally similar and fall within the same frequency range as those of the Arnoux’s beaked whale, rather than the killer whale. Of the two killer whale types observed in Prydz Bay, the most common had behaviour and morphology typical of Type B killer whales, while the other had morphology typical of Type A. Although we show that the sounds are not likely to be killer whale Type C calls, this would be the first recorded occurrence of Arnoux’s beaked whales in Prydz Bay. Arnoux’s beaked whales are a rarely seen, cryptic whale species.
Biodiversity and big data to investigate the link between biosonar sensing and flight control in bats
Authors: Müller Rolf , Hu Yihao , Junaidi Bibi , Kramer Samuel , Nnoka Chi , Parisi Phillip M. , Park Jungsoo , Rock Nicholas K. , Shing Jared , Srinivasan Udhaya , Su'eif Muhammad Syafi'ie , Yessayan Danny , Zhang Margaret , Grafe Ulmar , Liyanage Chandratilak De Silva , Malik Owais Ahmed , Ong Wee Hong
Published: November 2023

Any animal with dexterous mobility in complex natural environments needs powerful systems for sensing and mobility that also have to be well-integrated with each other. Echolocating bats that hunt in dense vegetation rely on biosonar integrated with flapping flight to accomplish this. The low-dimensional nature of the biosonar inputs together with the complexity of the bats' flight apparatus make this coupling a fundamental scientific challenge. To understand how bats can control the many degrees of freedom of their wings based on external information that is conveyed by only two one-dimensional echo trains, a flight tunnel has been instrumented with synchronized high-speed video cameras and ultrasonic microphones. The array recordings can provide data volumes that are large enough to enable deep-learning analyses of the biosonar echoes and the flight kinematics. These analyses will be applied to reducing the dimensionality of ultrasonic inputs, the kinematic outputs, and discovering the relationship between the essential dimensions of biosonar and flight. The tunnel has been installed on the island of Borneo to take advantage of the local bat biodiversity as a source of variability that can be exploited in a comparative approach to identify functional traits that are essential to sensorimotor integration in echolocating bats.
Extraction of acoustic features of calls of five Platypleura species using the field recordings
Authors: MATSUO IKUO
Published: November 2023

Five Platypleura species are distributed in the south of Amami Island in Japan. At particular, P. albivannata, and P. yayeyamana are distributed at the same area in Ishigaki island. The survey of P. albivannata, which is endangered species, is important problems for conservation. Although it is necessary to discriminate between these species, it is difficult to discriminate between them from the morphology, that is, visual information. It is necessary to discriminate with these species by using another cue. In this presentation, we proposed the analysis methods to extract acoustic features dependent on Platypleura species to the south of Amami Island in Japan. We primarily aimed to examine whether these classifications correspond to the resemblance in the time and frequency domain of calling songs. Furthermore, we tried to extract characteristics that can be used for species identification in monitoring endangered species, P. albivannata. We found that maximum peak frequencies are feasible for species identification, especially for the detection of P. albivannata in the wild.