bluuebunny/crossref_metadata_2025 huggingface dataset:
The localization of virtual source reproduced by the crosstalk cancellation system under different direct-to-reverberation energy ratios conditions
Authors: Tan Wei , Rao Dan , Wang Yewei , Yu Guangzheng
Published: November 2023

This study explores the localization of virtual sources reproduced by the crosstalk cancellation (CTC) system under reverberation environments with different direct-to-reverberation energy ratios (DRRs). Binaural room impulse responses in rectangle rooms are simulated by high-order image source method. Two independent key variables, the reverberation time (RT) and the distance of the sound source to the listener, are employed to manipulate DRR through simulation. Subsequently, a subjective localization experiment based on the CTC system is virtually conducted using earphone reproduction. The results show that the azimuth localization in horizontal plane is almost impervious by RT but is subjected to the change of the source distance. Specifically, as the distance of sound source increases, the perceived azimuth of lateral virtual sources exhibits a bias towards the front, accompanied by larger variances. The results indicate that reflections with small delays have a more detrimental effect on sound localization compared to the late reverberation with large intensity, which may be associated with the inhibition of late reflections based on the precedence effect. Additionally, the localization data are analyzed and explained using binaural cues, including the interaural cross-correlation coefficient, the interaural time difference (ITD), and interaural level difference (ILD).
Underwater acoustic surveys in the eastern Clarion Clipperton Zone
Authors: Parnum Iain M. , Flynn Adrian , Donnelly David M. , Clarke Michael
Published: November 2023

A drifting, underwater sound recording system was developed and deployed for acoustic surveys of vocalizing marine mammals in the eastern Clarion Clipperton Zone (CCZ), Northern Tropical Pacific. The system was designed to position an Ocean Instruments Sound Trap 500HF recorder and hydrophone at a depth of 450 m. A depressor vane was inserted halfway along the drop line, with shock cord, to minimize hydrodynamic noise. The surface line included a Spotter V2 buoy that provided real-time tracking of the location of the surface line. The recording system was deployed ten times in the CCZ, between November 2020 and October 2021. Deployment length was between two and seven days. All deployments were set to continuously record underwater sound with a sample frequency of 288 kHz. Acoustic data were analyzed using the CHORUS software to manually review recordings, and an FM signal detector (in MATLAB) was used to detect potential biological sounds. A variety of marine mammals were detected, including Delphinidae species, Physeter macrocephalus (sperm whales); and clicks likely to be from Ziphiidae species (beaked whales). Beaked whales have been previously visually sighted in the CCZ, but to our knowledge these might be the first acoustic recordings of them in the CCZ.
Real-time cavitation monitoring based on the entropic analysis of ultrasound RF signals
Authors: Tu Juan , Song Renjie , Guo Xiasheng , Zhang Dong
Published: November 2023

The violent inertial cavitation activity generated in high intensity focused ultrasound (HIFU) treatment has a risk of damaging healthy tissues around the target area, so that it is necessary to monitor the degree of cavitation during the treatment. Entropy, as a non-model-based statistical parameter, can effectively characterize the effect of cavitation on the structure of scatters within tissues. Thus, a real-time cavitation monitoring system was established based on the entropy analysis of ultrasound radio frequency (RF) signals, and the degree of cavitation was evaluated through entropy images. Based on the two-dimensional average filtering method, we achieved real-time monitoring of cavitation through the reconstruction of entropy image and the binarization of cavitation regions, breaking the inherent limitation of current systems that can only perform cavitation monitoring between HIFU pulses. The results showed that the entropy image retained more frequency components, which could determine the time and location of cavitation earlier and display cavitation areas. Moreover, as the acoustic pressure increased, the advance of cavitation indication in the entropy images became earlier. This method might provide a feasible evaluation scheme for improving real-time cavitation monitoring during HIFU treatment and was expected to become an effective reference index for imaging in HIFU surgery.
Ultrasound-responsive hydrogel microcapsules for on-demand drug release
Authors: Field Rachel D. , Jakus Margaret A. , Chen Xiaoyu , Human Kelia A. , Zhao Xuanhe , Chitnis Parag V. , Sia Samuel K.
Published: November 2023

Hydrogel-based implantable systems offer viable solutions for localized drug delivery but often lack the ability to easily achieve on-demand actuation or real-time tuning of release kinetics in response to physiological changes. Here, we present a hydrogel microcapsules produced using two-phase microfluidics that can release drugs on demand as triggered by focused ultrasound (FUS). The biphasic microcapsules consist of an outer phase of mixed molecular weight (MW) poly(ethylene glycol) diacrylate that mitigates premature payload release and an inner phase of high MW dextran with payload that breaks down in response to FUS. Compound release from microcapsules could be triggered as desired; 0.4 μg of payload was released across 16 on-demand steps over days. We detected broadband acoustic signals amidst low heating, suggesting inertial cavitation as a key mechanism for payload release. Overall, FUS-responsive microcapsules are a biocompatible and wirelessly triggerable structure for on-demand drug delivery over days to weeks.
Acoustic lens that diffuses plane waves composing of multiple spherical obstacles
Authors: Masukawa Hidetoshi , Takahashi Yoshinori
Published: November 2023

Recently, a non-electrical smartphone loudspeaker based on acoustic horn has been created and marketed. An acoustic horn is directional and has the advantage of propagating strong sound pressure in the direction the horn is facing. However, it has the disadvantage that sound pressure cannot be expected in any direction other than the direction in which the form facing. This study proposed an acoustic lens in the form of a cylinder composed of multiple spherical obstacles. The density of the sphere was calculated using the phase difference equation and the equation proposed by Kock et al. The density of the sphere at the center of the lens is lower than at the circumferential direction. This change in density slows down the apparent sound speed passing through the further from the center. In this work, FDTD simulations were performed to evaluate the sound directivity for the acoustic lens. This work also test manufactured the acoustic lens and performed an experiment in an anechoic chamber to evaluate the characteristics of the lens.
Investigation of heat transfer at the outer combustor wall on self-sustained thermoacoustic oscillations in a Rijke tube
Authors: Evans Molly , Zhao Dan
Published: November 2023

Thermoacoustic oscillations have plagued combustion systems for decades and are becoming increasingly relevant as engines become more powerful, more compact, and more eco-friendly. These oscillations arise from constructive coupling between unsteady heat release and acoustic pressure waves, and result in strong pressure oscillations that can inhibit flame stability and induce component failure. In this work, a simple numerical model is used to study the effects of the temperature distribution of the outer combustor wall on the thermoacoustic stability of a Rijke tube. A Galerkin series expansion of the linearized acoustic governing equations is coupled with a classical G-equation premixed flame model to determine the minimum energy required to maintain stability for various system configurations, and results are compared against computational fluid dynamics simulations for select cases.
Enhancing heat-driven acoustic characteristics of standing wave thermoacoustic engines by using corrugated stack
Authors: Guo Lixian , Zhao Dan
Published: November 2023

The present work considers the heat-driven acoustic characteristics and dynamic thermal-fluid flow fields of a standing-wave thermoacoustic engine (SWTAE) by using sinusoidally shaped corrugated stack surfaces. 3-D numerical SWTAE models are developed and validated, aiming to examine the heat-driven acoustic effects caused by different corrugation amplitudes and wave-lengths of the sinusoidal stack surface. The results demonstrate that corrugated-shaped stack channels increase the contact area of the working gas in the stack area, and the thermos-acoustic conversion is more amplified. Compared to the SWTAE with uniform-shaped stack, the corrugated-shaped stack exhibit enhanced acoustic power output while maintaining a constant acoustic oscillation frequency. With the corrugation peak and wave-length of the sinusoidal stack are 2 and 0.2 mm, respectively, the amplitude and acoustic power of the acoustic pressure oscillations increase by 10.12% and 17.31%, respectively, in comparison with that of the conventional SWTAE. However, when the corrugation peak exceeds 0.4 mm, stronger nonlinear acoustics and flow effects are observed in the stack channels, leading to a reduction in the heat-driven acoustic power output, and thermo-acoustics energy conversion efficiency. The developed model highlights the effects of the corrugated-shaped stack on enhancing acoustic power output and thermo-acoustic conversion efficiency.
Effects of temperature difference and operating pressures on heat-driven acoustic characteristics and nonlinear behaviors in a looped tube traveling wave thermoacoustic engine
Authors: Guo Lixian , Zhao Dan
Published: November 2023

In this work, the output heat-driven acoustic characteristics and dynamic thermal-fluid flow fields in a looped-tube traveling-wave thermoacoustic engine (TWTAE) are numerically investigated. Emphasis is placed on optimizing acoustic power output from the TWTAE by varying its operating pressure and temperature difference across the regenerator. For this, a time domain full-scale 3-D traveling-wave TAE model is developed, and then validated by comparing with those results obtained from the experimental data available in the literature. The present results indicate that the acoustic pressure oscillations and the acoustic power are increased with increased operating pressure of the working gas. Furthermore, nonlinear acoustics and flow dynamics in the heat-driven acoustic and flow fields of the TWTAE such as vortex generation around the regenerator and Gedeon streaming are observed. Considering the comprehensive acoustic characteristics, the optimal heat-driven acoustic power output, and thermo-acoustics energy conversion efficiency are achieved, as the working air pressure is set to 0.4 MPa. Increasing the temperature difference across the regenerator can further improve the acoustic power output from the TWTAE. In summary, the present 3-D model can be used as a design tool for predicting and optimizing looped tube traveling-wave TAE performances with detailed thermos-fluid dynamics and acoustics characteristics.
An experiment to measure changes in violin frequency response due to playing-in
Authors: Piacsek Andrew A. , Lowery Seth
Published: November 2023

There is a widespread (but not universal) conviction among luthiers and performers of stringed instruments that a new instrument will sound “better” after it has been played for a certain amount of time. It is not uncommon for instruments to be mechanically stimulated to accelerate the process. The goal of the present experiment is to determine whether sustained mechanical stimulation of previously unplayed violins produces measurable changes in bridge admittance or radiativity. Our test instruments comprised three sibling violins (Andre Tellis, model 200), two of which were excited continuously for 12 weeks using different methods, while the third served as a control. Once per week during the excitation period, we measured bridge admittance with a laser vibrometer and radiativity in an anechoic chamber for each violin using the hammer tap method. The mass of each violin was also recorded prior to each measurement to account for fluctuations in moisture content. The resulting frequency response functions were analyzed within specific bands for changes that followed a trend over time or exceeded the standard deviation derived from a set of baseline measurements. Preliminary results do not show any significant changes in either the bridge admittance or radiativity for any of the violins.
Lab-scale research on acoustically transparent stacks for hot exhaust jets in cooler cross-flow
Authors: Leav Orddom , Cazzolato Benjamin , Howard Carl
Published: November 2023

From the exhaust stack of open cycle gas turbine power stations, the sound radiated is strongly refracted in the near-field by the thermal and velocity gradients of the jet. Research undertaken by the authors has identified that the presence of a cooler cross-flow leads to a bent-over plume downwind of the exhaust stack and a significant increase in sound in the far field by up to 10dB downwind when compared to spherical spreading. This paper is the first in a series that explores a unique “acoustically transparent silencer,” which prevents this by separating the sound from the flow. The concept of the approach is demonstrated in this paper, with aero-acoustic simulations conducted on a supercomputer and small-scale experiments in a wind tunnel. The numerical simulations have predicted the effects of using an acoustically transparent exhaust stack to reduce the refraction of sound in the near field, which reduced the lobes in the acoustic directivity downstream of the exhaust by up to 4.5 dB. This was further supported by experimental results in a wind tunnel with a reduction of up to 4 dB. These results were used to assist in the second iteration of designs for the Refrastack in a subsequent paper.
Development of a thermal aging model for sound-absorbing polyurethane foam
Authors: Yang Sung Soo , Kang Yeon June , Lee Jung Wook , Park Sung Hwan
Published: November 2023

This research aims to establish a reliable thermal aging model of sound-absorbing polyurethane foam (PUF). To achieve this objective, accelerated testing was conducted in a heat chamber under various conditions. The transport parameters (open porosity, high-frequency limit of the dynamic tortuosity, viscous characteristic length, thermal characteristic length, and static thermal permeability) of original and aged PUF were characterized and investigated. Curve fitting was performed to predict the value of each transport parameters corresponding to the level of thermal aging from the collected data. The thermal aging model of PUF was constructed using the Layton model and Arrhenius equations, which showed good agreement with the measured data. By employing the proposed thermal aging model, it became possible to forecast the acoustic behavior of PUF at different aging temperatures and aging periods. Subsequent testing of PUF sample materials confirmed the validity and efficiency of the developed aging model. These findings provide a crucial reference for creating a predictive model for the acoustic behavior of PUFs undergoing thermal aging and offer valuable insights for designing an accelerated testing approach.
Determination of sound velocity by resonant ultrasound spectroscopy and complementary inelastic scattering
Authors: Bessas Dimitrios
Published: November 2023

In this talk, I am going to highlight the complementarity of resonant ultrasound spectroscopy and (nuclear) inelastic scattering of synchrotron radiation for determining the sound velocity in condensed matter systems. Following a very brief introduction, characteristic examples of condensed matter systems relevant to material science in which the sound velocity is extracted using both experimental methods at ambient pressure and low temperature will be shown. The strengths of (nuclear) inelastic scattering of synchrotron radiation for obtaining the sound velocity at extreme pressure (up to ca. 200 GPa) and temperature (up to ca. 2000 K) relevant to geosciences will be discussed and relevant examples will be presented.
Neural and behavioral binaural hearing impairment and its recovery following noise-induced cochlear synaptopathy
Authors: Benson Monica A. , Peacock John , Sergison Matthew D. , Stitch Dominik , Tollin Daniel J.
Published: November 2023

Noise-induced cochlear synaptopathy refers to a loss of synapses in the inner ear but no change in audiometric thresholds. Animal studies have focused primarily on peripheral hearing measures to diagnose synapse loss, while suggesting binaural listening deficits such as speech-reception-in-noise result from this disorder, but have not accounted for the possible regeneration of synapses. To address this, we measured binaural physiological and behavioral function in adult guinea pigs with noise-induced synaptopathy. Physiological measurements extended to two months post noise exposure. While common audiological assessments showed temporary threshold loss, reduced evoked potential amplitudes indicative of synaptopathy and measurable binaural electrophysiological hearing deficits post exposure, all measures recovered by two months including binaural behavior. Suspected regeneration of synaptic ribbons occurred by two months post exposure and cochlear histology revealed no synaptic loss two months post exposure. We show that the same noise exposure protocol that caused synaptic loss in prior studies causes physiological binaural processing deficits in the brainstem and that the regeneration of synapses corresponds with recovered binaural processing including behavior. Results suggest that functional recovery of ribbon synapses post a single moderate noise exposure is sufficient to restore binaural hearing abilities.
Clinical relevance of the cat as a model of hearing loss
Authors: Fallon James , Trang Ella , Wise Andrew
Published: November 2023

Reliable, clinically relevant, animal models of hearing loss are vital to both increase our understanding of changes that occur during hearing loss and to test the safety and efficacy of interventions designed to treat hearing loss. This presentation will outline the variety of deafening techniques than can be used in the cat to induce either profound or partial hearing loss over a range of ages (from neonatal to adult). We will also discuss the range of behavioral measures, long-term and acute electrophysiological measures (including DPOAEs, CAPs, ABRs), and histological techniques (including whole cochlea imaging) that are available when using the cat as a model that make it an invaluable resource for the hearing field.
Predicting trends in the sound transmission loss performance of steel-framed wall partitions using yield strength
Authors: Shafer Benjamin M.
Published: November 2023

Mechanical properties of beams and panels are commonly used for calculating structural loads and deformation under stress and strain. Stress and strain analysis for steel beams may result in the determination of yield strength, a commonly reported steel framing property in the steel industry. This characteristic of steel framing is rarely, however, linked to trends in sound transmission loss (STL). This paper provides an analytical basis for linking the yield strength of steel framing to the STL of vertical double-leaf partitions with a focus on acoustic impedance of the beam. Experimental data are shown that validates this analytical basis. These results may be used as evidence for including the reporting of the yield strength in standardized test reports.
Comparison of FEA and SEA methods for predicting railway-induced vibration propagation through over-station developments
Authors: Timms David , Brown Graham , McGuckin Damian
Published: November 2023

The design process for Over-Station Developments (OSDs) includes consideration of the potential impacts of railway-induced vibrations to ensure that structure-borne noise and occupant comfort standards are maintained during railway operations. Should an OSD be identified as sensitive to railway operational structure-borne noise or vibration impacts, the inclusion of adequate track vibration isolation measures becomes essential for mitigation. This paper presents a comparative study of two methodologies for predicting vibration propagation through structures and consequent structure-borne noise levels—Finite Element Analysis (FEA) and Statistical Energy Analysis (SEA). Specifically, this study provides an indication of the range of predicted results and emphasizes the computational efficiency and scalability of these methods when determining track isolation requirements for structures.
Striation-based beamforming using a horizontal array
Authors: Kim Donghyeon , Byun Gihoon , Kim J. S. , Kim Daehwan , Song Heechun
Published: November 2023

Conventional beamforming (CBF) based on plane waves is widely used for direction finding with a horizontal array deployed in ocean waveguides. However, CBF suffers from loss of spatial coherence due to the inhomogeneous field produced by constructive and destructive interference between multipath arrivals. Moreover, the grazing angle propagation leads to a bias in the estimated bearing. In this work, we revisit the striation-based beamforming (SBF) that exploits the waveguide invariant representing the complex wave propagation [Zurk and Rouseff, J. Acoust. Soc. Am. 132, EL264 (2012)]. Our approach involves a preliminary processing to restore the spatial coherence across the horizontal array, followed by CBF. Experimental results illustrate the performance improvement of SBF over CBF in terms of array gain, resolution, and bias.
Pioneering time-of-arrival localization with cable-free and battery-free transponders
Authors: Pu Lina , Luo Yu , Song Aijun
Published: November 2023

In traditional underwater acoustic positioning methods, reliance on systems such as Long Baseline (LBL) and Short Baseline (SBL) localization utilize transponders that actively transmit acoustic pulses. These systems are typically powered by cables and often result in constrictive deployment. The adoption of cable-free and battery-free transponders can greatly enhance the flexibility of deployment. This change facilitates large-scale implementation, thereby providing precise positioning services across extensive areas. However, localization with passive transponders faces unique challenges. It has been widely accepted that battery-free nodes are unsuitable for time-of-arrival (ToA) localization. The primary reason is the wakeup delay varies based on location and environment, which introduces an unpredictable offset into the time lapse between the transmitted and received pulses. To overcome this challenge, we model the wakeup delay of passive node, considering the hardware characteristics of the passive node and the multipath acoustic channel. Moreover, we propose a ToA-based localization framework specifically tailored for battery-free transponders. In this paper, we will verify our wakeup delay model and assess the performance of the proposed localization method through experimental results. This new approach marks a significant departure from the existing effort, making localization with passive transponders feasible.
Sound absorption coefficient measurement for various building elements
Authors: Oh Yang Ki , Kang Min Woo
Published: November 2023

The current sound absorption coefficient testing measurement method, ISO 354, primarily focuses on materials used for surface coverings or equivalent sound absorption objects. However, there are other building elements such as lightweight partition walls and windows that do not have solid structures behind them. These elements may allow sound to transmit to adjacent interior spaces or escape to the outside. On the other hand, the transmitted sound is expected to be rebounded into the measurement room when the test material is placed on a hard and thick surface as described in ISO 354. The test was conducted in a reverberation chamber located at the center of three consecutive acoustic testing chambers: reverberation-reverberation-anechoic. The testing chambers are equipped with test openings between them and are fully isolated from one another. The purpose of the test was to confirm whether the current measurement method reflects the influence of the assumed rebounded sound. The sound absorption coefficients were measured with the specimen installed on the floor, representing the ISO 354 condition, and comparisons were made to the conditions where the specimen was installed in another reverberation chamber opening and in the anechoic chamber opening.
Soundscape of Sandiaoling Ecological Tunnel
Authors: Juan Shiang-I , Chen ChihHsuan , Dinh Quynh X. , Harsono Kevin , Hezekiah Evan , Houssein Mahad Moussa , Kayatekin Fatma , Tamariska Stirena Rossy , Wagiri Felicia , Yang Hao-Chun , Tsaih Lucky
Published: November 2023

The Sandiaoling Ecological Tunnel, originally an abandoned railway, has been transformed into a 1852 m long ecological bike path. Constructed with stones and bricks, the tunnel now features an elevated bike path supported by threaded iron rods, with a gentle water flow beneath. As the tunnel has two main sections and an open transition area in between it, the entrance (open), the middle of the tunnel (enclosure), near the tunnel exit (semi-open), and the transition area between the two main sections are selected as the four soundscape study locations. The study follows ISO-12913 soundscape study method to document essential sound sources, paths, and levels. Odeon Room Acoustic Software is used to study the simulated sound source propagations. The research documents a taxonomy of sound sources, encompassing both natural and man-made sounds. The tunnel's atmosphere is characterized by quietude, monotony, coldness, and resonance. The average equivalent sound pressure level in the four measured locations is 59dBA. Frequency spectrums and simulated reflection patterns are also examined. During the soundwalk, the overall listening impression of the tunnel is described as delightful, relaxing, peaceful, and harmonious with nature. The atmosphere inside the tunnel evokes a sense of serenity and tranquility.
Speed of sound of ultrasonic pulses in fluids relevant to biomedical research
Authors: Nehring Grace I. , Bingham Emily E. , Hoffmeister Brent , Viano Ann
Published: November 2023

Tissue specimens are commonly stored in phosphate buffered saline (PBS) solution and formalin solution. Ultrasonic measurements of tissues may be performed in these same solutions. The goal of the present study was to measure the speed of sound in these fluids over a typical range of room temperature. An aluminum block with a 0.500-in. precision machined step was placed in a 1 L specimen tank containing the fluid of interest. The specimen tank was positioned in an 8 L tank of water with a thermostatically controlled heater and circulating pump, to which cold packs could also be added. A 7.5 MHz transducer was mechanically moved and scanned over the block to acquire echoes from either side of the step. The time difference between echoes received from either side of the step was measured to determine the speed of sound in the fluid. Measurements were performed in 0.5°C intervals from 15.0 to 25.0°C. The speed of sound was found to increase with temperature for both fluids, with ranges of 1484–1512 m/s for PBS and 1509–1532 m/s for formalin.
Ventilated silencer based on layered Helmholtz resonators
Authors: Crivoi Alexandru , Du Liangfen , Fan Zheng
Published: November 2023

This study investigates the performance of a multilayer sound-attenuating metamaterial with ventilation capabilities. The design incorporates arrays of Helmholtz resonators embedded within the wall structure. Each cell of the barrier's front wall is a Euclidean polygon, triangular, square, or hexagonal, housing a parallel array of resonators interconnected via an axial ventilation duct. The sound attenuation performance of these barriers is meticulously examined using the lumped parameter theory and the transfer matrix method (TMM), complemented by finite element (FE) simulations. The results indicate that sound attenuation in the audible frequency range (300–2000 Hz) can be significantly enhanced by employing multiple layers of resonators, each layer assigned a unique peak resonance frequency. Despite the design's inherent trade-offs between barrier thickness, ventilation capacity, operational frequency range, and overall sound attenuation, its structural simplicity and straightforward theoretical performance estimation methods make it a promising candidate for applications requiring a specific attenuation spectrum. The sound-blocking performance of the design is further validated through impedance tube experiments, which show a reasonable agreement with the numerical predictions, thereby affirming the efficacy of the proposed design. The performance of multilayer design is also compared with the similar ventilated barriers proposed in the recent studies.
Computational optimization of acoustofluidic devices for advanced particle micromanipulation
Authors: Kolesnik Kirill , Rajagopal Vijay , Collins David J.
Published: November 2023

Acoustofluidic devices, which combine principles of acoustics and microfluidics, have emerged as a promising platform for biological micro-object micromanipulation due to their non-invasive, accurate, rapid, and label-free qualities. Acoustofluidic devices have found utility in various biomedical applications including single-cell studies, point-of-care testing, lab-on-a-chip studies, and tissue engineering. In this work, we present novel device configurations which enable complex and high-resolution control of suspended micro-objects. The studies presented here utilize computational analysis to optimize (1) traveling surface acoustic wave device dimensions, (2) the configuration of a planar acoustic resonator that integrates a structured surface, (3) the thickness of the coupling layer and superstrate materials for bulk-wave transmission, and (4) the shape of acoustically actuated 3-D microstructures. These devices were verified experimentally to generate highly localized acoustic fields and acoustic streaming effects enabling rapid and spatially controllable particle capture, transport, and patterning. In doing so, this work demonstrates that computational analysis is an integral part of the development of acoustofluidic devices for advanced micromanipulation, which have extensive potential in biomedical applications.
Exploring player’s feelings on clarinet mouthpiece geometry using artificial blowing machines and airflow simulations
Authors: Yoshinaga Tsukasa , Yokoyama Hiroshi , Shoji Tetsuro , Miki Akira , Iida Akiyoshi
Published: November 2023

The mouthpiece geometry of single-reed instruments has been known to have a great impact on sound quality and playability. Although many researchers have investigated the effects of the geometry using artificial blowing machines or user case studies, few attention has been paid to the essential cause of physical changes in the instrument. In this study, we propose a method combining the artificial blowing machine and numerical flow simulations to explore the player’s feelings about the airflow and sound generation in the clarinet mouthpiece. With the artificial blowing machine, the mouth pressure, as well as lip force, were systematically changed using a pressure regulator and strain gauge. At particular conditions, the numerical flow simulation was conducted by solving fluid–structure interactions with the Navier–Stokes equations and the one-dimensional beam equation. The playability of the mouthpiece was shown by the changes in oscillation threshold pressures and sound spectral characteristics, whereas the cause of the changes could be described by the airflow pressures inside the mouthpieces. The results suggest that the combination of the artificial blower and the flow simulations can be effectively used for clarifying the cause of changes in players’ feelings.
Two distinct mechanisms of tonal sound production in supersonic jet impingement
Authors: Edgington-Mitchell Daniel , Weightman Joel , Nogueira Petronio
Published: November 2023

The interaction of high-speed jets with a perpendicular surface produces not only broadband sound, but “impingement tones,” that can be more than 30 dB above the broadband noise. It is well recognized that these tones are the result of an aeroacoustic resonance, driven by a feedback loop between the jet nozzle and the plate. However, the exact mechanism by which the tones are produced remains a topic of some dispute; some researchers locate the source within the core of the impinging jet, others in the wall jet generated after impingement with the plate. In this work, we demonstrate that both camps have correctly identified sources; there are two distinct mechanisms, with two distinct locations. The relative strength of these sources depends on the geometry of the problem, but we show that they can actually coexist at a single condition. Decomposition of high-speed schlieren data directly visualizes the location of these sources as a function of jet operating condition.
A quantified risk-based approach to construction noise and vibration management
Authors: Davis Dave J.
Published: November 2023

The management of environmental noise and vibration impacts from construction activities can significantly influence the scheduling, program, activities, and costs of construction projects. While there are a number of mitigation and management measures available to the construction site to control their environmental impacts upon neighboring sensitive receivers, efforts to reduce impacts should be focused on taking the steps that will result in the greatest reduction to the overall project’s environmental risk profile. In order to identify the countermeasures with the highest efficacy to reduce the overall risk, it is advantageous to quantify noise and vibration impacts based on ordinal metrics such as decibels and degree of annoyance. This paper describes a proposed method to quantify construction noise and vibration risk in order to improve the identification and selection of the countermeasures that should be implemented on site.
Growth rates of harmonics in nonlinear vortex beams
Authors: Gokani Chirag A. , Cormack John M. , Hamilton Mark F.
Published: November 2023

Nonlinear effects in acoustical vortex beams were described originally in a numerical investigation by Marchiano et al. [Phys. Rev. E 77, 016605 (2008)]. The focus of the present investigation is the rate at which nonlinearly generated harmonics grow with distance in the field of a vortex beam radiated by a monofrequency or bifrequency source as a function of the topological charge. The motivation is a paper by Richard et al. [New J. Phys. 22, 063021 (2020)] suggesting that the rate of nonlinear distortion in the direction of the beam axis is increased in a vortex beam due to the lengthened propagation distance along the ray paths spiraling about the beam axis. In the present work, harmonic growth rate is characterized in terms of both amplitudes along different ray paths and total power across the beam. Growth rates are calculated and compared for harmonics generated in nonlinear vortex beams radiated by sources with different topological charges and amplitude distributions. Both unfocused and focused beams are considered. The likelihood of shock formations is also explored. [CAG is supported by the ARL:UT Chester M. McKinney Graduate Fellowship in Acoustics.]
Measuring excess attenuation in littoral environments: Evolution of a measurement system
Authors: Vecchiotti Andrea , Turo Diego , Vignola Joseph , Stengrim Matthew D. , Foeller Jeff , Byrd Maranda , Nguyen Kian , Ryan Teresa J.
Published: November 2023

Atmospheric sound propagation measurements over long distances are generally lacking in the literature. This work presents the evolution of the system deployed to collect high spatial and temporal resolution synchronized acoustic and meteorological data. Specifically, the mature configuration includes: a long-range acoustic device capable of source levels up to 140 dB; up to four 7-channel acoustic arrays; two 7-m temperature profiling masts; and a scanning Doppler LIDAR system for volumetric wind profiling at ranges up to several kilometers. This work presents lessons learned over the various iterations of the system such as the design and evolution of the excitation signal used; physical configuration of the components of the system; logistics and planning concerns; post-processing challenges; and quality control considerations.
High spatial resolution long-term temperature profiling to inform near-shore atmospheric sound propagation
Authors: Stengrim Matthew D. , Vecchiotti Andrea , Foeller Jeff , Nguyen Kian , Byrd Maranda , Turo Diego , Vignola Joseph , Ryan Teresa J.
Published: November 2023

Atmospheric sound propagation depends on factors such as surface characteristics and meteorological parameters. Effective numerical modeling of atmospheric sound propagation requires reliable and realistic input parameters. One of the most influential factors is the air temperature profile. This work examines the application of experimentally determined air temperature profiles in acoustic modeling of littoral environments. Long term measurements of near-surface air temperature profiles over water and marsh grass are presented. Data have been recorded using temperature loggers affixed to two permanent 7 m masts. The loggers were positioned with a 1 m vertical spacing. A common approach to characterize the near-surface boundary layer uses Monin–Obukhov Similarity Theory (MOST). This work compares high spatial resolution air temperature measurements with measurement-informed profiles based on MOST. The development of a more experimentally grounded set of assumptions will ultimately contribute to the improvement of atmospheric acoustic transmission loss models in near shore environments.
Influence of mesoscale meteorological observations on near shore excess attenuation prediction
Authors: Vecchiotti Andrea , Ryan Teresa J. , Vignola Joseph , Stengrim Matthew D. , Foeller Jeff , Turo Diego
Published: November 2023

This work focuses on numerical modeling of atmospheric sound propagation in a near-shore environment that is informed by concurrent meteorological observations. The atmospheric acoustic measurement layout places the source approximately 500 m from shore with one acoustic receiver array at the shoreline and a second acoustic receiver array approximately 350 m inland. The space between the shoreline and the inland receiver array consists of highly uniform marsh grass vegetation. The concurrent meteorological observations include high resolution temperature profiling at two locations (one over land and one over water) along with scanning Doppler LIDAR wind profiling measurements in the source-to-receiver direction. These meteorological measurements inform the input parameters used in a parabolic equation solver. The numerical predictions are compared to the measured transmission loss values to evaluate model sensitivity to input parameters.
Auditory cortical coding of task-relevant variables during active listening
Authors: Schenider Nathan A. , Malina Michael , Krall Rebecca F. , Williamson Ross S.
Published: November 2023

Auditory-guided behaviors are ubiquitous in everyday life, whenever auditory information is used to guide our decisions and actions. The primary route for auditory information to propagate from the ACtx is through intratelencephalic (IT) and extratelencephalic (ET) neurons in layer (L) 5. To investigate the behavioral role of IT and ET neurons, we engaged mice in a head-fixed auditory categorization task and longitudinally monitored populations of L5 IT and ET neurons using two-photon calcium imaging. Clustering analyses of these populations revealed heterogenous response motifs that correlated with various stimulus and task variables, but with distinct expression patterns across learning and task proficiency. Our results suggest a tradeoff of information between two distinct populations within L5, with IT projections playing a role in initial task acquisition, while ET projections are recruited and reinforced throughout the learning process. This underscores the differential roles of distinct descending systems and contribute to our understanding of how auditory information is processed and utilized to guide decision-making and action.
Individual profiles amidst a multiethnolect: Acoustic hetereogeneity in London English
Authors: Kerswill Paul , Gibson Andy , Sharma Devyani , McCarthy Kathleen , Passoni Elisa , Hellmuth Sam
Published: November 2023

Multicultural London English (MLE; Kerswill and Torgersen 2008; Cheshire et al., 2011) arose in working class areas of London around 30 years ago through intensive, multiethnic social contact (Kerswill and Torgersen, 2021). The variety’s highly systematic phonological system has been seen as displacing traditional London vernacular varieties including Cockney, which have moved further East (Fox, 2015). MLE and Standard Southern British English are two strands among many, interwoven with features of the earlier London vernacular and features of non-MLE varieties (Sharma and Sankaran, 2011). Using preliminary data from a new project, Generations of London English, we present an acoustic analysis that shows both the stability and emerging maturity of MLE as well as strands of continuity from the past. The GOAT vowel shows a diverse range of variants indexing social class, ethnicity, age, and gender. By contrast, all Londoners participate in GOOSE-fronting, which is thus primarily an index of age, and women lead FOOT-fronting, a city-wide change showing less ethnic and social class sensitivity. A generalized use of labels such as MLE risks mischaracterizing the sociophonetic reality. We argue for analysis of individual phonetic profiles as unique intersections of historically layered features, diffusing differently through a heterogeneous population.
How does the choice of acoustic measures influence evaluation of voice therapy treatment outcomes?
Authors: Madill Catherine , Chacon Antonia , Szalay Tuende , Nguyen Duy D.
Published: November 2023

There exists a large amount of predominantly low-level evidence that behavioral voice therapy is effective but there is limited evidence that one therapy is more effective than another. Variability in voice therapy treatment outcomes research leaves clinicians with little guidance in the selection of treatment. A range of acoustic outcome measures with differing sensitivity for detecting voice change are used, statistical analyses vary and experimental design presents both pros and cons regarding applicability of outcomes to real-world clinical settings. In this presentation, a review of acoustic outcome measures, statistical methods, and research design used to evaluate treatment for two clinical cohorts—muscle tension voice disorder and gender affirming voice therapy—will be presented. Two treatments investigated across the two cohorts (Resonant Voice Therapy and Sob Voice Therapy) will be used to demonstrate how acoustic analysis has been used and how implications of results differ. Method: Comparison of data available in published literature will be presented alongside new data as yet unpublished. Acoustic measures, research design, and statistical tests used will be evaluated for sensitivity to voice change, level of evidence, and translation to clinical practice.
Deep learning and beamforming comparison of source ranging in a laboratory tank
Authors: Dobbs Corey E. , Neilsen Tracianne B.
Published: November 2023

Deep learning has been shown to be useful for ocean acoustics applications, such as source ranging. The variable nature of the ocean causes difficulty when attempting to apply trained models to new datasets. To explore ways to train supervised deep learning models that are robust to environmental variability, laboratory tank measurements can be used. A laboratory tank presents a system where uncertainty in the acoustic environment can be adjusted in a more controlled manner. In this work, recordings of ultrasonic chirps (50–200 kHz) are obtained at different source-receiver positions. Time-averaged spectral density levels are used to train one-dimensional convolutional neural networks that predict source-receiver range. The trained networks are tested on data obtained under different conditions. Data augmentation techniques are applied to increase the models’ robustness in the presence of limited uncertainty. Metrics such as root mean-squared error and mean absolute percent error are used to quantify the model’s performance. The results from deep learning with single channel recordings and multi-channel recordings are compared with traditional beamforming methods on the multi-channel data. [Work supported by the Office of Naval Research.]
Simulation-aided machine learning: Applications in underwater acoustic perception and explainability
Authors: Hunter Alan , Bryan Oscar , Clark Edward , Sanford Ciaran
Published: November 2023

Underwater acoustic applications of machine learning are challenging due to sparsity, lack of diversity, and often uncertain labeling of training data. This is due to low levels of consumer relevance. One approach to the problem is to collect and label more data. However, this is expensive and unlikely to fully address the issue. A complementary approach is to use simulation for generating synthetic data and augmenting the machine learning pipeline. This also enables explainability by encoding human knowledge of the underlying physics. We present two case studies in simulation-aided machine learning. The first is an application to underwater munition dumpsite characterization using multi-view sonar surveys. Self-supervised learning has been used to pre-train a generative deep neural network to predict alternate views using unlabeled data. Subsequently, training is completed using a small volume of labelled data. Simulation was necessary for successful pre-training to continuously fill viewing angle gaps caused by limited and rigid survey directions. The second application is autonomous tactical planning for uncrewed underwater vehicles. Reinforcement learning policies have been trained to passively detect and localize underwater acoustic sources. These have been trained and evaluated in a fully synthetic environment, using a sophisticated propagation model together with empirical environmental parameters.
Effective feature fusion via analysis of quantitative similarity matrices among various acoustic features for underwater active target detection
Authors: Shin Sungjin , Kim Geunhwan , Hwang YoungSang , Kim Juho , Choo Youngmin
Published: November 2023

For underwater active target detection, using conventional machine learning technique is limited and unsuitable because of small training data samples and diversity of environment. Therefore, to apply conventional machine learning for underwater acoustics target detection, three methodologies can be manipulated (1) feature, (2) architecture, and (3) learning strategy. In this paper, we implement various acoustic features in terms of feature similarity and feature fusion. From numerous studies in field of acoustics, various acoustic feature extraction methods have been proposed such as Mel-frequency cepstral coefficient, Gammatone-frequency cepstral coefficient, cepstral coefficient, short-time Fourier transform, constant Q transform, and wavelet packet decomposition. In this paper, we calculate a quantitative similarity between acoustic features by interpreting their data distributions with the corresponding probability densities in a reduced dimension. Furthermore, we fuse the acoustic features by simple concatenation. Fusion of a strongly correlated two-dimensional features tends to follow the performance of poor one, whereas the fusion of weakly correlated features improves performance remarkably. The performance improvement by the fusion of weakly correlated features is attributable to complementing acoustic information each other.