bluuebunny/crossref_metadata_2025 huggingface dataset:
Passive acoustic monitoring of biological soundscapes in a changing climate
Authors: Freeman Lauren A. , Duane Daniel , Freeman Simon
Published: April 2023

Passive acoustic monitoring of biological soundscapes offers a long-term view into ecosystem state. This is particularly well studied for coral reefs and tropical littoral systems with evidence for similar capability in temperate and deep ocean biologically rich ecosystems. Monitoring ecosystem state under both climate change impacts and changing human usage is a critical piece of understanding how climate change and human use impact ecosystems. Passive acoustics allow for wide area coverage of an ecosystem heartbeat, and changes in key bioacoustic metrics in coral reefs indicate shifts from healthy coral dominated systems to more degraded systems with increased macroalgal cover. These shifts are typically associated with increased ocean temperatures and/or increased human use. The primary controls on coral reef soundscapes are time of day and year. Here, broad comparisons between warmer and cooler years at long term coral reef monitoring sites in Hawaii will be discussed, as well as summer versus winter biological soundscapes at temperate sites in New England. Reef soundscapes encompass contributions from a wide variety of marine flora and fauna, some of which can be identified to species level through characteristic calls and tracked with a high degree of fidelity through passive acoustics alone.
Climate-induced changes in temperature, salinity, and sound speed in the global ocean
Authors: Madiligama Madusanka , Zhang Likun
Published: April 2023

Oceans play a significant role in climate change by absorbing the earth's excess heat and transporting heat from one location to another. Melting and reducing ice coverage, rising sea levels, ocean acidification, and changes in underwater sound propagation are a few impacts of global warming on oceans. Marine lives have been threatened by many of these alterations, such as interference of their communications and reduction of their habitable places, resulting in the ocean ecosystem imbalance. Ocean datasets containing temperature and salinity are necessary to measure the warming rates and places, access the magnitude and extent of the impacts, and consider mitigation policies. Data collected by traditional in situ measurement techniques are insufficient for this purpose because of the scarcity of the measurements in the vast ocean. Here, an idea to overcome the limitation is proposed by using machine learning to infer the ocean temperature and salinity from satellite-observed sea surface temperature and salinity data that are broadly available. Following the predicted temperature and salinity values, global warming indicators, such as ocean heat content and mixed layer depth, are examined. Also examined are the underwater sound speed variations.
I know what you did last winter: Bowhead whale anomalous winter acoustic occurrence patterns in the Beaufort Sea, 2018–2020
Authors: Diogou Nikoletta , Halliday William D. , Dosso Stan , Mouy Xavier , Niemi Andrea , Insley Stephen
Published: April 2023

Global warming is affecting the Arctic at a faster pace than the rest of the world, causing an urgent need to monitor ecosystems to detect possible climate-related changes. To this end, five passive acoustic datasets were recorded in the southern Amundsen Gulf (eastern Beaufort Sea) from September 2018 to September 2020 and analyzed for Bering-Chukchi-Beaufort (BCB) bowhead whale calls using a combination of automated and manual detections. Results indicate a large variation in bowhead occurrence patterns between the two years. For 2018–2019, we obtained the first evidence of bowheads overwintering in what is typically their summer foraging ground. Examination of the following year’s recordings sheds light on whether this interruption in bowhead annual migration was an anomaly or part of an ongoing phenological shift due to climate change. Time series of remotely sensed sea ice concentration at the study area were considered over the last seven years in interpreting differences in migratory behavior of the whales. Statistical quantification of seasonal patterns and habitat preferences of bowheads, based on the 2018–2019 acoustic data, are presented to provide context to BCB bowhead ecology. Passive acoustic monitoring is an indispensable tool in discerning whale responses to a changing ocean in the Arctic.
Ocean acoustics and the UN decade of ocean science for sustainable development
Authors: Becker Kyle M. , Spence Heather , Smarsh Grace
Published: April 2023

The United Nations Decade of Ocean Science for Sustainable Development (Ocean Decade) was initiated in 2021 and runs until 2030. The Ocean Decade seeks transformative ocean science solutions that connects people to our oceans to bring about positive change. This motivated an idea that ocean acoustics has a role to play among the larger ocean sciences as they relate to climate change and the emerging blue economy. On World Ocean Day 2021 (June 8), the Ocean Decade Research Programme on the Maritime Acoustic Environment (OD-MAE) was included among the first Ocean Decade actions endorsed by the United Nations Intergovernmental Oceanographic Commission of UNESCO (IOC). Inspired by Lindsay’s “wheel of acoustics,” the OD-MAE program is envisioned as a hub for coordinating studies involving rigorous and principled used of sound to address questions relating to all aspects of ocean science and engineering, development, policy, and management. The program seeks to support the development of both people and capabilities that enable a quantitative linkage between an acoustic environment and the physical and biological components and processes occurring within that environment. This presentation will introduce the OD-MAE program, describe some of the initiative underway within it, and provide information on how to get involved.
Temporal dependence of acoustic propagation in a seagrass meadow over diurnal and annual timescales
Authors: Lee Kevin M. , Ballard Megan , Capistrant-Fossa Kyle , McNeese Andrew R. , Cushing Colby W. , Jerome Thomas S. , Wilson Preston S. , Dunton Kenneth H.
Published: April 2023

Seagrasses serve major ecological roles in biodiversity promotion, coastal protection, and nutrient cycling. Furthermore, seagrasses have been proposed as a nature-based solution to mitigate effects of climate change due to their capacity for sequestering marine carbon. Current global estimates of seagrass coverage are uncertain; therefore, developing improved methods to assess seagrass coverage and rates of decline are critical to promote sustainable seagrass conservation efforts. Acoustic propagation in seagrass meadows is highly sensitive to oxygen bubble production via photosynthesis and gas volumes encapsulated within seagrass tissue, both acting as biophysical markers. This paper discusses an acoustic method to monitor seagrass oxygen production and biomass with high temporal resolution and over long time-scales. An 18-month acoustic propagation experiment was conducted in a seagrass meadow located in a shallow bay on the Texas Gulf of Mexico Coast. A piezoelectric sound source transmitted broadband frequency-modulated chirps (0.5–100 kHz) every ten minutes, and the signal was measured on horizontal hydrophone array. Dissolved oxygen, photosynthetically active radiation, water temperature, salinity, and depth were concurrently measured with oceanographic probes. Additionally, cores were collected for point-estimates of seagrass biomass. Our work demonstrates that acoustic propagation offers a valuable alternative to experimental measurements of photosynthesis. [Work sponsored by NSF.]
Small animal cerebral microvascular imaging with super-resolution ultrasound: Techniques and applications
Authors: Song Pengfei
Published: April 2023

Super-resolution ultrasound (SR-US) is an emerging microvascular imaging technology that provides a micron-scale spatial resolution with tens of millimeters of depth of imaging penetration. The unmatched combination of high spatial resolution and deep imaging penetration opened new doors for many brain imaging applications that benefit from cerebrovascular biomarkers. Recently, SR-US has found its niche in small animal brain applications thanks to its unique capabilities of extending the optical-imaging-level spatial resolution to subcortical, deep brain regions. In this presentation, I will first introduce existing SR-US imaging techniques that are tailored to small animal brain imaging applications. Topics include fast SR-US methods, 3D SR-US imaging, and phase aberration correction for intact skull imaging. I will then focus on reviewing brain imaging applications that use SR-US to characterize cerebral mirovasculature in the aging, stroke, and Alzheimer’s Disease brain. Finally, I will introduce the new functional super-resolution imaging technique that combines SR-US with functional ultrasound (fUS) to realize whole-brain neural activity recording at a micron-scale spatial resolution.
Ultrasonic subwavelength imaging with blind structured illumination
Authors: Lin Jinuan , Ma Chu
Published: April 2023

The resolution of ultrasonic imaging systems suffers from the diffraction limit. To solve this problem, we develop a blind structured illumination microscopy (blind-SIM) system that achieves far-field subwavelength resolution in underwater ultrasonic imaging systems. By illuminating the object with multiple structured illumination (SI) patterns generated by scattering media with subwavelength features, the spatial frequency mixing between the object and the SIs converts evanescent waves to propagate waves that can reach sensors in the far field. In this work, the acoustic SIs are generated by randomly distributed micro particles in water. The image of the object is then reconstructed from multiple measurements (each produced by a SI pattern) utilizing computational reconstruction algorithms where the precise knowledge of the SIs is not required. The developed ultrasonic blind-SIM system has the potential in improving the ultrasonic imaging resolution in medical diagnoses, underwater acoustic imaging, and communications. Our system largely reduces the imaging hardware complexity and improves the imaging speed compared with existing ultrasonic subwavelength technologies that mostly rely on the precise localization of time-varying contrast agents.
Ultrasound modulation of neurons by sonogenetics
Authors: Chen Hong
Published: April 2023

Focused ultrasound (FUS) can noninvasively deliver ultrasound energy to target any area in the whole brain with combined depth penetration and spatial focusing that cannot be achieved with other external stimulations. Sonogenetics, integrating focused ultrasound with genetic engineering, can achieve noninvasive control of neurons genetically modified with ultrasound-sensitive ion channels. Crucial to the development of sonogenetics has been the identification of ultrasound-sensitive probes to control neurons. FUS propagation through the tissue can generate mechanical and thermal effects within its focal region. This talk will present recent progress in the development of mechanosensitive and thermosensitive ion channels as sonogenetic probes. Recent success in using sonogenetics for noninvasive and cell-type-specific behavior control of freely moving mice will also be presented. This noninvasive and cell-type-specific neuromodulation approach has the promise to advance the study of the intact nervous system and uncover new ways to treat neurological disorders.
Drug-mediated acoustic reporter genes for mammalian cell ultrasound imaging
Authors: Welch Phoebe J. , Howells Alessandro R. , Kim John , Forest Craig R. , Lian Xiaojun L. , Shi Chengzhi
Published: April 2023

The newly established field of genetically encoded ultrasound contrast agents in the form of gas vesicles could expand the uses of medical ultrasound imaging for cell specific deep tissue imaging. However, current gene constructs encoding for these gas vesicles require significant cell processing to ensure sufficient gas vesicles are formed within the cell to produce ultrasound contrast. Here, we describe a drug-inducible and drug-selectable acoustic reporter gene construct that can enable gas vesicle expression in mammalian cell lines, which we demonstrate in wild type HEK293T cells. Plasmid integration was validated using fluorescence microscopy, and flow cytometry was used to establish single cell clones of the cells. Gas vesicle expression was optically and ultrasonically verified, with an 80% improved signal to noise ratio in cells expressing gas vesicles compared to negative controls. This technology presents a new reporter gene paradigm by which ultrasound can be harnessed to visualize specific cell types in vitro and invivo for various applications, including cellular reporting and cell therapies.
Cellular response to photo-mediated ultrasound therapy
Authors: Subramanian Karthikesh Madhumithra , Yang Xinmai
Published: April 2023

Photo-mediated ultrasound therapy (PUT) is a novel technique that combines relatively low-pressure focused ultrasound and low-fluence laser to enhance cavitation inside blood vessels. Due to the increased shear and circumferential stresses, the enhanced cavitation activity can achieve anti-vascular effect. The role of endothelial cells in the antivascular effect of PUT was explored by quantifying the release of vasodilators-nitric oxide and prostacyclin from endothelial cells after PUT, laser-only, and ultrasound-only therapies in an in vitro vessel mode. PUT was able to suppress both the vasodilators by more than 5% with concurrently applied 0.5MPa ultrasound pressure at 500 kHz and 15 mJ/cm2 laser fluence at 532 nm. Both the laser-only and ultrasound-only therapies at the similar levels resulted only in elevation of these vasodilators with respect to control. The suppression of vasodilators by PUT was justified with cavitation signals observed using passive cavitation detection and apoptosis observed with Annexin V-fluorescein isothiocyante (FITC), at respective levels. The endothelial cellular response to PUT further motivated us to evaluate the effect of PUT on melanoma cells and evaluate cytotoxic effect through MTT assay. PUT was able to destroy cancer cells through the cavitation effect when compared to laser-only and ultrasound-only therapies at the similar energy levels.
Assessing the effects of ultrasound parameters on P-selectin expression for active targeting of nanotherapeutics
Authors: Burgess Mark , Tylawsky Daniel , LaPlant Quincey , Heller Daniel
Published: April 2023

P-selectin is a nanotherapeutic target for enhanced passage of nanoscale drug delivery systems across the vascular barrier and into tumors via transcytosis. While many tumors express P-selection, radiation can be used to induce expression in tumors devoid of P-selectin. This study aims to test whether ultrasound can elicit a similar response through mechanical or thermal bioeffects. Preliminary experiments were performed in vitro using brain tissue derived mouse endothelial cells. A Vevo SoniGene system was used to sonicate cells with low-intensity (2 W/cm2) pulsed ultrasound in a 12-well cell culture plate. Upregulation of P-selectin was seen using a 60 second treatment duration at 50% and 100% duty cycles via flow cytometry analysis. The mean fluorescence intensity, normalized to nontreated cells, was 32 + /- 17.4 and 103 + /- 37.2 for 50% and 100% duty cycles, respectively. Viability remained high with 72.6 + /- 14.5 and 77.5 + /- 8.3% of cells viable for both 50% and 100% duty cycle groups, respectively. These results highlight the potential of ultrasound for active targeting using non-ionizing energy and for tumors where radiation is not feasible. Future studies will identify associated bioeffects and compare ultrasound with radiation for nanotherapeutic delivery in small animal tumor models.
Ultrasound-spectroscopic-imaging study on the effects of local mechanical stimulation on living human induced pluripotent stem cells
Authors: Fujiwara Natsumi , Matsumoto Takaki , Nagakubo Akira , Kino-oka Masahiro , Ogi Hirotsugu
Published: April 2023

Living cells sense various mechanical stimuli and respond to them by adjusting their tissue morphogenesis, self-renewal, and differentiation. Because stem cells seem to be more sensitive to the stimuli, many studies have been conducted to control their behavior. However, many of these mechanisms remain unexplored, because stimulus extends throughout the cells or causes cell-damaging. In this study, we have developed a focused ultrasound spectroscopic technique for noninvasively applying local mechanical stimulation in a single cell and combined it with an optical microscopy to systematically investigate its effects on the function and morphology of the cell. Our original system allows ultrasonically monitoring living cells for longer than 24 h. Appling this technique for human iPS cells, we find out an ultrasound absorption band at ∼160 MHz, which we attribute to the resonance of the nucleus. This indicates that we can stimulate cell nucleus selectively and effectively. Furthermore, we have established a method to evaluate the height distribution of cell colonies and revealed that human iPS cell colonies show very characteristic changes in height distribution during their growth.
Tuning microbubble-mediated endothelial drug delivery outcome with monodisperse microbubbles of different sizes
Authors: Wang Yuchen , Li Hongchen , Meijlink Bram , Beurskens Robert , van der Steen Antonius F. , Johnson Benjamin , Kooiman Klazina
Published: April 2023

Microbubble-mediated drug delivery using polydisperse microbubbles has shown differences in drug delivery outcome due to the microbubble’s differences in size and, thus, acoustic response. The aim of this study was to investigate whether monodisperse microbubbles can achieve controllable sonoporation and tunnel formation. Using the Horizon microfluidics platform, monodisperse phospholipid-coated microbubbles were produced with radii of 1.25–3.5 μm. Single microbubble-endothelial cell interactions (n = 82) upon insonification at 2 MHz (200 kPa PNP, 10 cycles) were investigated in vitro using confocal microscopy and ultra-high-speed imaging (10Mfps). No cellular response was observed for the 3.5 μm microbubbles having excursion amplitudes (Rmax-R0) ranging from 0.3 to 0.6 μm. PI uptake and resealing pores were observed more often for the 1.5 μm microbubbles (50%) with excursion amplitudes ranging from 0.5 to 0.9 μm than for the other microbubble sizes. PI uptake and tunnel formation was most observed for the 1.25 μm microbubbles (46.6%; 0.4–0.6 μm excursion amplitudes) and least for the 3 μm microbubbles (4.2%; 1.0 μm excursion amplitude). No other cellular responses were observed for the 3 μm microbubbles. The excursion ratio (Rmax-Rmin/R0) better separated the tunnel formation events (>0.6) from other cellular responses (0.1–0.6). This study shows the importance of monodisperse microbubbles for tuning drug delivery.
Ultrasounds trigger reversible permeability of the cerebrovascular endothelium in a novel 3D-bioprinted model of the human blood-brain barrier
Authors: Mirheydari Mona , Pun Sirjana , Haworth Kevin J. , Pomeranz Krummel Daniel , Barrile Riccardo
Published: April 2023

The blood-brain barrier (BBB) restricts the penetration of therapeutic agents to the brain. Focused ultrasound (FUS) insonation of microbubbles has enhanced drug delivery via a temporary opening of the tight junctions of the BBB. Rodents are often used for testing novel therapeutic strategies. However, biological discrepancies existing between rodents and humans impedes the translation of some results. We investigated the effect of FUS transient disruption of a human microphysiological model of the BBB consisting of human brain endothelial cells cultured within a 3D-bio printed scaffold designed to reconstitute the architecture of a perfused blood vessel. Cavitation activity was detected in the model when perfused with Lumason microbubbles and exposed to 500 kHz ultrasound at 0.4 MPa for 10 ms pulse duration and 2 Hz pulse repetition frequency. An increase in extravasation of a dye beyond the endothelial layer was detected within 2–3 h of ultrasound insonation. Our results support that this system could be used for targeted BBB opening with a human cell culture model. Moreover, this system holds a promise to further the translational study on US-mediated drug delivery and the development of personalized therapies for patients with brain cancer and other neurovascular disorders.
Investigation of the ultrasound-mediated toxicity mechanisms of various sonosensitive drugs
Authors: Singh Kritika , Vasilyeva Alexandra , Hu Luna , Ruan Jia-Ling , Gray Michael , Stride Eleanor P.
Published: April 2023

There is a current pressing need to develop novel platform cancer therapeutics that are efficient, reduce side effects, and are minimally invasive. One of these platforms is photodynamic therapy where light is used as an external stimulus to activate drugs at a target location; however, clinical applications are limited due to poor light penetration. Previously, it has been shown that ultrasound with and without cavitation nuclei can be used to activate photodynamic drugs (sonodynamic therapy – SDT); however, the mechanism of this activation remains unclear. Recently, sonoluminescence has been detected in real time using a photomultiplier tube setup, up to millisecond temporal resolution; however, the spectra of light produced as well as the associated intensity has yet to be characterized. A proposed mechanism for SDT is that this light produced can activate photodynamic drugs at the target location resulting in reactive oxygen species (ROS) production (which leads to cell death). However, through temporal uncoupling of ultrasound application and compound administration in vitro and in vivo, this work shows that intracellular uptake of compound via cell permeabilization (sonoporation) plays an important role in SDT-induced cell death and potentially explains the high levels of cell death observed for comparatively low concentrations of ROS.
Real-time musical performance across and within extended reality environments
Authors: Hamilton Rob
Published: April 2023

The design of real-time digital musical instruments, both novel as well as the emulation of traditional musical performance practices using computer systems, has always required nearly imperceptible latencies between controlling gesture and expressed sound. Sound and music based experiences built within immersive visual rendered spaces often struggle to provide seamless articulate control of rendered dynamic output. Working across and within extended reality environments, the complexity of the challenge continues to evolve with current generations of hardware and software pushing core and graphics processors to their respective limits. The introduction of networked performance spaces has only added to the complexity, resulting in the need for additional latency mitigation strategies from both the technical and artistic domains. This paper will discuss recent creative and technical strategies and concerns in the design, development and use of real-time virtual musical instruments.
Real-time considerations for a source-time dominant auralization scheme
Authors: Christian Andrew , Ali Randall
Published: April 2023

A well-designed recording system can capture a moving source without risk of distortions, knowledge of the source or path, or transmission of information back to the source (i.e., a smartphone can reasonably record a plane flying overhead). This necessarily happens in real time. It would be good if signal processing schemes for auralization possessed these properties. Recent work on the NoTAP method of auralization proposed an asynchronous sample rate conversion scheme that keeps track of the (nonuniform) rate of incoming samples to formulate an effective incoming sampling frequency. This value allows the method to predict what frequency regions at the receiver are vulnerable to aliasing or imaging artifacts. Strategies of oversampling and filtering can be used to eliminate these problem regions while preserving as much of the original content as possible given the desired receiver sampling frequency. This approach creates a situation where the receiver processing can run independently of the source/path processing making it attractive for real-time implementation. This presentation discusses the challenges associated with producing a truly real-time scheme. A three-way tradeoff emerges between an interpolation mechanism that generates decorrelated noise, the computational burden, and the nearness to absolute real-time with which one wants the scheme to run.
Testing and modeling of nozzle and eartip acoustics for balanced armature tweeter implementation in earphones
Authors: Varanda Brenno R.
Published: April 2023

Balanced armature (BA) receivers can be used as tweeters in earphones to increase their treble and ultra sound bandwidth. Key factors that influence the 9–20 kHz response of earphones when implementing BA tweeters are shown through experimental validation and comparison to newly-developed SPICE lumped parameter models (LPM). While the BA location and acoustic passage inside the earphone are important factors, the study focuses on how changes to the design of the earphone’s nozzle and the choice of ear-tips affect the 9–20 kHz frequency response. Improvements to existing SPICE LPM elements are provided, based on finite element analysis of the acoustic passageway that is formed between the compressed eartip and ear-simulator couplers. The model is compared to measurements from various nozzle and eartip configurations, validating its effectiveness to capture the earphone’s high frequency response due to changes to the earphone’s nozzle and eartip geometry.
Aluminum foams with complex pore topologies for acoustical applications
Authors: Kankanamalage Pulitha G. , Puppo Jake , Schaffarzick Denver , Sharma Bhisham
Published: April 2023

Metal foams are used in various industries due to the great variety of properties they possess such as high strength-to-weight ratio, high energy absorption, and the ability to endure extreme conditions. However, despite their desirable properties, traditional metal foams lack acoustic absorption properties because of their stochastic open porous structure—a function of the foaming process. Additive manufacturing (AM) can allow the fabrication of more complex foams; however, current metal AM methods provide significant processing and scalability challenges, especially in printing aluminum parts. Here, we present an alternative method for fabricating open-celled aluminum sound absorbers with controlled cellular architectures. The method relies on modeling the cellular templates using an implicit, field-based modeling method. The templates are then fabricated by combining polymer-based AM techniques and converted into aluminum Duocel® foams using ERG Aerospace Corporation’s proprietary foaming technology. The acoustical properties of the fabricated foams are then measured using a normal incidence impedance tube method. Our results show that this method allows the fabrication of highly complex cellular architectures that may be optimized to obtain application-specific multifunctional performance.
Implementation of active cancellation of noise entering a window
Authors: Nelson Robert , Dittberner Andrew , Thompson Stephen C.
Published: April 2023

Environmental noise propagating through an open window may be cancelled by a sparse array of transducers placed in the window frame. This approach towards global noise cancellation mitigates noise pollution at its source while retaining the light and ventilation received from an open window. While theoretical work has been established for this process, all calculations have relied on far field equations leaving the near field not well understood. This was resolved by modeling the system in COMSOL Multiphysics with increasing complexity. Experimental implementation revealed additional flaws in the design including undesired vibrations and insufficient power from the key transducers. Vibrations in the window’s crossbar were identified via accelerometers and suppressed by the addition of an aluminum brace. Experimental results will be presented.
Numerical prediction nonlinear heat-driven acoustics behaviours in standing-wave thermoacoustic engines using stress-blended Eddy simulation method
Authors: Guan Lixian , Zhao Dan
Published: April 2023

The present work investigated a standing-wave heat-driven thermoacoustic engine (SWTAE) system by capturing its nonlinear thermoacoustic features with three-dimensional (3D) unsteady Reynolds-Averaged Navier-Stokes (URANS) and hybrid URANS/LES (large Eddy simulation) models such as detached-Eddy simulations (DES) and stress-blended Eddy simulation (SBES) models. The comparison studies show that the prediction of the acoustic power of SWTAE using URANS is about 21.0% lower than that using LES, while the results from SBES and DES are relatively in good agreement with LES. Comparative studies of nonlinear hydrodynamics in the flow fields show that the results from SBES are closer to LES than DES, which can be attributed to the SBES model providing a faster transition to an explicit LES model outside the wall boundary layer. Furthermore, the heat transfer characteristics are compared by analyzing heat leaks and transversal heat flux, and it is found that the URANS model over-estimates the heat transfer characteristics, while the results of the other three models are relatively smaller than those obtained by URANS. In conclusion, the SBES model has great potential to be applied in simulating thermoacoustic nonlinear, heat transfer and flow behaviors of heat-driven SWTAEs.
Experimental investigation on microfluidic devices for particle separation using standing surface acoustic waves
Authors: Zhao Dan , Yang Justin Tay Jun
Published: April 2023

In this work, we designed and experimentally tested a microfluidic device for particle separation by using standing surface acoustic waves (SSAW). Emphasis is being placed on an effective microfluidic device being capable of continuous separation of particles in a microchannel design on its size. For this, we developed a miniaturized (e.g., lab-on-a-chip) system for biological and chemical analyses. For demonstration, we experimentally demonstrated that separation of dissimilarly-sized polystyrene particles suspended in water medium was successfully achieved. Numerical simulations were conducted by using COMOSL Multiphysics 5.0 to investigate the effects of sheath layer thickness and particle size on separation efficiency of the microfluidic device. The present numerical and experimental findings were then applied to propose an improved design and fabrication process of Standing surface acoustic waves devices, which has great potential for biological applications.
Circular breathing—An introspective study across all types of wind-instrument generators
Authors: Braasch Jonas
Published: April 2023

Circular breathing is an extended technique for wind instruments to play a continuous sound. To do so, the performer pushes out air temporarily stored in the cheeks while inhaling. In the second part of the cycle, the player exhales, refilling the air in the cheeks while driving the wind instrument. The two main challenges of this technique are maintaining a constant embouchure and air supply. This talk spans from the author’s Hyperspecialization technique on the soprano saxophone that involves all major types of wind-instrument generators, including brass, flute, double-reed, single-reed, and free-reed generators. The history, difficulty, and outcome for each generator type will be discussed. The free-reed generator is the easiest to perform with circular breathing because the free-reed resonance frequency only depends on fingering and cannot be controlled by embouchure. The embouchure for the flute generator is very different from the other circular breathing techniques, and transferred knowledge and experience can hardly be applied. The type of wind-instrument generator itself is not always a good indicator of the easiness of performing circular breathing. For brass embouchures, for example, the didjeridu adapter was much easier to perform with circular breathing than the cornetto mouthpiece because of the latter’s tight embouchure requirements. For double reeds, the duduk reed was more challenging than the bassoon reed, because it requires much more air to excite the instrument.
Bifurcation behavior and underblowing on the bass crumhorn
Authors: Campbell Murray , Maugeais Sylvain , Woolley Alan
Published: April 2023

The crumhorn is a double reed musical wind instrument with a narrow cylindrical bore and a characteristic hook-shaped curve near its open end. It is played by blowing air through a narrow slit into a windcap which surrounds the reed. Crumhorns were made in several sizes, from soprano to contrabass, and in the sixteenth and early seventeenth centuries were frequently employed in wind ensembles in Germany, Italy and the Netherlands. Since no lip control of the reed is possible, the instruments cannot be overblown, and the playing range of a standard crumhorn is limited to a major ninth. On the bass crumhorn, however, a sixteenth century source mentions a technique for extending the lower range of the instrument by up to a perfect fifth by reducing the blowing pressure below its normal level. In 2000, Gibiat and Castellengo investigated these underblown notes experimentally and associated them with period doubling cascades. In the present work, the bifurcation behavior of an artificially blown bass crumhorn has been studied experimentally, and the results are compared with bifurcation diagrams calculated using a continuation method.
Experimental tests of free reed instrument simulations
Authors: Foti Quinn , Sabin Max , Cottingham James P.
Published: April 2023

Recent simulations using finite element software have been used to study the fluid dynamics, pressure acoustics, and structural mechanics couplings involved in self-sustained reed oscillation and reed-pipe coupling in free reed instruments. This paper reports on two experimental studies related to these simulations. One of these involves reeds of the type used in harmonicas and accordions. The results verify that the assumed dependence of sounding frequency on blowing pressure, which has long been used as a benchmark for a successful simulation is correct for blowing pressures close to those normally used in playing the instruments. At higher pressures, however, a variety of anomalous results can occur. The second study involves finite element models of pipes from the free-reed Asian khaen. Pipe simulations produce results for the input impedance of the pipe that agree very well with experimental measurements. A pressure acoustics model of the khaen pipe coupled to a free reed produces results that appear realistic for sound radiation but does not realistically capture the mechanism of the self-sustained oscillation of the reed driven by airflow. Measurements in the current study show that this model does provide approximate quantitative agreement with the predictions of the simulation.
Evaluating the efficacy of music programs in hearing aids
Authors: Sandgren Emily , Alexander Joshua M.
Published: April 2023

Hearing aid processing of music is much less thoroughly researched than hearing aid processing of speech. This study evaluates the efficacy of programs specifically designed for music listening in state-of-the-art hearing aids. Normal-hearing participants rated the sound quality of music samples recorded from seven hearing aid brands in programs designed for speech or music. Preliminary results confirm the significant degradation of music quality caused by hearing aids. However, the music programs for three of the seven manufacturers significantly improved music quality compared to their speech programs. An analysis of signal processing and acoustic features relating to efficacy will be presented.
A brief rocket noise introduction for the interested ASA meeting attendee
Authors: Gee Kent L. , Hart Grant W. , Lubert Caroline P.
Published: April 2023

It can be difficult for ASA meeting attendees to find an entry point into topical special sessions; they may be interested in learning about a field outside their own but are unfamiliar with terminology, physical processes, and the challenges that motivate different research studies. For the topic of rocket noise, this presentation is intended to help attendees from different ASA technical areas feel more prepared to understand the significance and details of the other talks in this session. But because there is far more to discuss than can be addressed in a single presentation, attendees are also referred to a recent review article on launch vehicle acoustics [C. P. Lubert et al., J. Acoust. Soc. Am. 151, 752-791 (2022)].
Updated frequency-dependent directivity indices for large solid rocket motors
Authors: Hart Grant W. , Gee Kent L. , Cook Mylan R.
Published: April 2023

For many years, empirical models for rocket noise radiation relied on the directivity indices published in NASA SP-8072 (K. Eldred, 1971). Because these indices had known issues, NASA led a campaign to update the indices using a Space Shuttle reusable solid rocket motor (RSRM). The RSRM measurements, involving a polar arc at a radius of about 80 nozzle exit diameters, resulted in updated directivity indices (Haynes and Kenny, AIAA 2009–3160). However, because the arc origin was placed at the nozzle exit plane, James et al. [Proc. Mtgs. Acoust., 18, 040008 (2012)] corrected the low-frequency indices using an estimated dominant source position for each frequency and assumed spherical spreading. This paper revisits that correction effort by using near-field vector intensity measurements from a similar, but smaller diameter and lower thrust, GEM-60 motor to determine the frequency-dependent origin to adjust the apparent angles and distances of the measurements. Additionally, an effort is made to account for RSRM plume impingement downstream that likely resulted in lower high-frequency levels than would have been measured if the plume had been entirely free. This analysis results in updated, frequency-dependent directivity indices for a large solid rocket motor. Their applicability to other rockets will be discussed.
Rocket noise predictions and scaling methods based on outdoor acoustic measurements
Authors: Kerrian Peter , McShane John , Larson Dan , Shah Parthiv , Cloutier David , Yang Michael
Published: April 2023

This paper will present follow-on work to the outdoor acoustic measurements that were presented at the May 2022 ASA conference for a static hot fire test of a rocket engine. The focus is on scaling the measured sound pressure levels to predict the acoustic performance of a different sized engine. Source models were developed based on the near field acoustic measurements and compared to far field measurements.
Acoustic overview of the Delta-IV Heavy NROL-91 launch
Authors: Yancey Matthew G. , Moats Levi T. , Cook Mylan R. , Hall Lucas K. , Anderson Mark C. , Hart Grant W. , Gee Kent L.
Published: April 2023

As commercial space launches continue to become more common, there is increasing interest in the subject of noise. The United Launch Alliance Delta IV Heavy is particularly interesting because of its three-core design with three widely separated engines. Measurements made by Brigham Young University at the NROL-91 launch on September 24, 2022, feature several microphones placed in an arc surrounding the launch facilities of the NROL-91 launch, ranging in distance from 670 m to 1.8 km. In addition, two long-range measurement locations (13.4 and 19.5 km) were included for propagation comparisons with an earlier Delta IV Heavy launch measurement (NROL-82). This presentation focuses on a description of the measurement made and several results, including spectra, directivity, and the sound power level calculated for the launch vehicle, as well as comparisons with the NROL-82 data.
Mobile sensing for the localization and tracking of acoustic sources in urban environments
Authors: Davis Dorian , Mahmoud Wagdy , Denis Max
Published: April 2023

In this work, the localization and tracking of acoustic sources in an urban environment is presented. Of particular interest is the performance of mobile acoustic sensors. In real world situations, sources are moving making it difficult to track their location especially in changing environments. The performance of mobile acoustic sensors is investigated. Beamforming and TDOA based techniques will be employed in various non-line of sight scenarios. The results and limitation of these techniques both numerically and experimentally will be discussed.
Wind-induced noise estimation of wind speed and direction within urban microspaces: Characterizing flow condition of urban environments
Authors: Mandjoupa Lirane , Gaye Samba , Mahmoud Wagdy , Denis Max
Published: April 2023

In this work, the flow conditions within urban microspaces are predicted from wind-induced noise. Wind speed and direction are estimated by fitting the spatial coherence of the wind noise distribution among closely spaced microphones measurements to the Corcos model in the least squares sense. The estimated wind speed and direction are compared to measure results. The estimated flow conditions of the measured urban areas are discussed.
Model based spectral feature analysis in reverberant acoustic fields
Authors: Aoki Emi , Gandhi Pratik , Norceide Flore , Chandra Kavitha , Thompson Charles
Published: April 2023

The spectral features of a reverberant acoustic field that can lead to improved source localization methods are investigated. Of particular interest are identification of deterministic and probabilistic features that characterize the environment and models of the acoustic transfer function that generate such features. For example, models that predict Schroeder’s invariant standard deviation in the pressure response at source-receiver distances where the direct sound approaches the reverberant field energy are proposed. Models examined include non-stationary Gaussian processes for the acoustic reverberant components and all-pass parametric models of the acoustic impulse response.
Remote acoustic sensing for urban air quality assessment
Authors: Estevez Hernandez Juan , Mahmoud Wagdy , Denis Max
Published: April 2023

In this work, sound pressure levels and air quality are measured around near roadways in urban areas. The measured sound pressure level data are compared to the air quality index to investigate the relationship between roadway traffic levels and particulate matter concentration. Additionally, the effects of wind speed and direction are investigated. Of particular interest are the upwind and downwind conditions. The results of this work will be presented and discussed.
Gunshot detection from audio excerpts of urban sounds using transfers learning
Authors: Ancel Jamelia , Mahmoud Wagdy , Denis Max
Published: April 2023

In this work, a pre-trained convolutional neural network is employed to detect gunfire from audio excerpts of urban sounds. The pretrained convolutional neural network is fined-tuned with transfer learned features to a new task using a smaller number of training signals. Two CNN methods are applied to the time-frequency representation of the audio signals. The first CNN method is based on classifying specific events in audio signals. The second CNN method is an image-based analysis method. The accuracy of the two CNN results will be compared and analyzed based on gunfire type and retrieved urban multipath conditions. A k-means clustering algorithm is employed to identify gunfire types and parametric modeling to retrieve the urban multipath conditions.
Cooperative verification of urban noise sources from generated acoustic and seismic waves
Authors: Abdulbasit Telha , Mahmoud Wagdy , Denis Max
Published: April 2023

In this work, co-operative verification of acoustic and seismic wave generating noise sources within an urban environment is presented. Sound and soil vibration produced from everyday urban noise sources including trains and vehicles are measured. Acoustic and seismic sensors can detect vehicles passively, independent of weather and daylight, at long ranges. Both signals contain contributions from the engine. Simulated and measured results will be presented and discussed
Acoustic energy harvesting of ambient noise urban environment
Authors: An Justin , Mahmoud Wagdy , Denis Max
Published: April 2023

In this work, the efficiency of engineered materials for converting ambient acoustic noise into electrical power is investigated. Of particular interest are 3D-printed acoustic metamaterials. Initial investigation will focus on sonic crystals acoustic metamaterials. Numerical simulations of the acoustic wave and sonic crystals interaction will be conducted. Of particular interests are the strong scattering interactions. 3D-printed samples will be measured and tested. The simulation and measurement results will be presented and discussed.
Comparing outcomes with the cloud-based and portable versions of an open-source hearing aid
Authors: Rallapalli Varsha H. , Hunt Martin , Garudadri Harinath
Published: April 2023

The open-source speech processing platform (OSP) is an open-source hearing aid (HA), developed to overcome proprietary restrictions of commercial HAs and pave the way for innovative HA technology through rigorous and reproducible research. This study evaluates portable and cloud-based platforms of the OSP that will enable a wide range of lab and field applications. The two platforms share common software applications for HA signal processing and objective outcome assessments (HO2). The cloud-based platform is hosted on a web server whereas the portable platform is accessed on a browser via a WiFi-enabled portable communication device. Listeners with mild to moderately severe hearing loss or normal hearing completed a word identification task (Modified Rhyme Test) in a 6-alternate forced choice paradigm using the HO2 app. Words were mixed with different levels of speech-shaped noise; presented via calibrated headphones or behind-the-ear receivers-in-the-canal for cloud-based and portable platforms, respectively. Signals were processed with individualized gain and compression ratios based on a clinically validated prescriptive formula. Results-to-date from four listeners show comparable range of word identification scores between platforms. The full dataset will also compare phoneme-level scores and response time measures generated from the HO2 app. Clinical research applications will be discussed. [Work supported by NIH-R44DC020406.]
Monte Carlo simulation of pure tone audiometry reveals threshold-dependent differences in error
Authors: Perry Trevor T. , Brungart Douglas S.
Published: April 2023

This study used a Monte Carlo simulation to evaluate the reliability of pure tone audiometry while incorporating information about the population distribution of thresholds. Results confirm that audiometric error (outcome threshold minus modeled threshold) is symmetric when simulated data are binned by modeled threshold. However, when data are binned by outcome threshold, the error depends on the relative distribution of modeled thresholds. When a realistic distribution is used, outcome thresholds of 0 dB HL show the lowest error rate. Bins with outcome thresholds <0 dB HL show a negative median error (outcome threshold < modeled threshold) and bins >0 dB HL show a positive median error (outcome threshold > modeled threshold). These results suggest that a substantial proportion of individuals who obtain a very good threshold during audiometric testing (−5 or −10 dB HL) are individuals who actually have higher thresholds, which are being underestimated. These findings are relevant for hearing conservation programs, which monitor for upward shifts from baseline thresholds. [The views expressed in this abstract are those of the authors and do not reflect the official policy of the Department of Army/Navy/Air Force, Department of Defense, or U.S. Government.]