bluuebunny/crossref_metadata_2025 huggingface dataset:
Functional ultrasound localization microscopy in the murine brain: Challenges and new techniques
Authors: Wang Yike , Shin YiRang , You Qi , Lin Bing-Ze , Lowerison Matthew R. , Song Pengfei
Published: July 2024

Functional ultrasound localization microscopy (fULM) is a new technique that combines the principles of ULM and functional ultrasound (fUS) to achieve brain-wide and micrometer-scale mapping of brain neural activities based on neurovascular coupling. The unique combination of high imaging spatial resolution, large imaging field-of-view, and deep imaging depth of penetration makes fULM a potentially transformative technology for numerous neuroscience applications where activities from both global neural networks and local neurocircuits need to be recorded simultaneously and continuously. At present, however, fULM suffers from many technical and pragmatic challenges, including low sensitivity and specificity to neural activities, the need of long data acquisition with continuous infusion of microbubbles and repeated simulations, and the lack of viable 3D imaging solutions that are essential for neuroscience research. In this presentation, I will first introduce the principles and technical challenges of fULM, followed by recent advances achieved by our group including (1) enhanced microbubble localization, tracking, and other post-processing techniques to boost fULM’s sensitivity to neural activities; (2) 3D fULM based on 2D matrix arrays that are compatible with mainstream 256-channel ultrasound systems; and (3) an awake fULM imaging platform for mice and rats that allows whole-brain, microscopic-scale recording of functional neural activities in awake animals.
Monitoring of neoadjuvant chemotherapy response of breast cancer with ultrasound localization microscopy
Authors: Porte Celine , Kohlen Matthias , Lisson Thomas , Magnuska Zuzanna , Winkler Brigitte Sophia , Rix Anne , Dencks Stefanie , Koczera Patrick , Schmitz Georg , Stickeler Elmar , Kiessling Fabian
Published: July 2024

Neoadjuvant chemotherapy (NAC) is the standard treatment for high-risk breast cancer, but less than 30% of patients exhibit a complete response, necessitating better preselection and monitoring. Ultrasound localization microscopy (ULM) offers potential improvements by providing super-resolution images of vasculature and functional features. To assess its efficacy, we applied ULM to breast cancer patients undergoing NAC, comparing their responses based on ULM features. Patients were evaluated before their first, second, and fourth NAC cycles, assessing tumor volume and employing contrast-enhanced ultrasound (CEUS) in split-screen mode. CEUS videos underwent postprocessing, involving MB localization and tracking, and motion compensation. ULM images, derived from tracked MBs, generated parameter maps for analyzing vascular changes and differences between responders and non-responders. Preliminary results of 14 patients revealed that during the first three cycles of NAC, the tumor volume as well as vessel coverage (i.e., ratio of vessel to tumor surface) of responders noticeably dropped. In contrast, non-responders showed only minor tumor size reduction and overall no decrease in coverage. Furthermore, the mean distance to the closest track was noticeably higher in non-responders. These findings, though preliminary, hint at ULM's potential for enhancing preselection and monitoring of NAC patients.
Acoustic emissions based estimation of the temporal changes in microbubble radius during ultrasonic excitation
Authors: Lee Hohyun , Arvanitis Costas
Published: July 2024

Our ability to study microbubble dynamics in vivo and link them to distinct mechano-biological effects hinges on our ability to accurately estimate the temporal changes in MB radius during ultrasonic excitation. Here, we hypothesize that real-time passive cavitation detection (PCD) monitoring combined with linear acoustic wave propagation theory can accurately estimate stable MB radius dynamics under in vivo conditions. To test our hypothesis, we employed numerical simulations, based on Rayleigh–Plesset modeling, followed by experimental validation, using calibrated PCDs with concurrent optical imaging of MB dynamics using high frame rate microscopy. Our method termed linear acoustic wave propagation and superposition (LAWPS) algorithm, combines Fourier series expansion with Euler’s relationship to estimate the acoustic emission (AE) from single MB, which is considered as a monopole source (i.e., R0 + ΔR < λ). LAWPS algorithm, which is independent of MB properties and, thus, can be linearly reversed to calculate MB oscillation radius from AE, was able to accurately capture the radiated pressure generated from a Rayleigh–Plesset MB modeling. Crucially, inverse LAWPS algorithm onto AE generated by Vokurka et al. resulted in the original MB model. Experimental observation using monodisperse MBs was able to accurately estimate the temporal changes in MB radius during 0.5 MHz ultrasonic excitation
Investigating the resonance response of a system of two ultrasound-driven lipid encapsulated microbubbles confined within a viscoelastic vessel
Authors: Yusefi Hossein , Helfield Brandon
Published: July 2024

Lipid encapsulated microbubbles, strongly characterized by the initial phospholipid concentration, are clinical ultrasound imaging agents. These microbubbles are commonly used as an ultrasound contrast agent and are being developed for therapeutic applications. In this work, we investigate the vibration dynamics of two microbubbles confined within a viscoelastic vessel. We developed a finite element model to study radial microbubble dynamics in a two-bubble system, as typical clinical doses result in closely spaced bubbles. Specifically, we study the effect of the vessel wall viscosity on the resonance behaviour of microbubbles in the frequency range of 2– 8 MHz. For two identical microbubbles, we observed a decrease in 50% in resonance amplitude as we increased the vessel viscosity from 0.1 to 1 Pa s as well as an 8% shift of peak resonance activity towards higher frequencies. Furthermore, we investigated the same system consisting of microbubbles with a lower initial phospholipid concentration and showed the same decrease in amplitude; however, the direction of shift of peak resonance was towards lower frequencies by 4%. Our work suggests that microbubble resonance behaviour is greatly affected by the vessel viscosity and that the extent and direction of bubble dynamics changes are dependent on shell characteristics.
A parametrization study of TEULM’s image reconstruction performance
Authors: Tuccio Giulia , Afrakhteh Sajjad , Demi Libertario
Published: July 2024

Time efficient ultrasound localization microscopy (TEULM) allows imaging the microvascular structures with reduced frame rates compared to standard ULM. The quality of reconstructed images relies on different parameters. In this study, we aim at understanding the links between TEULM performance and three key parameters: SVD k-value (representing the number of components considered as noise), the maximum linking distance (indicating the assumed maximum distance that a microbubble can cover between two successive frames), and the minimum length of a track. We generated TEULM density and dynamics maps, singularly varying these three parameters. Next, we evaluated the quality of TEULM images by means of a root mean squared error (RMSE), dice score, and Fourier ring correlation (FRC) analysis. A publicly available preclinical in-vivo dataset was used for this study. Results demonstrate that minimum track length and k-value have the greatest impact on both density and dynamic maps RMSE, whereas the minimum linking distance is the key factor influencing the dice score. Additionally, the relationship between these parameters and metrics is non-linear. Furthermore, the resolution measured by the FRC is negatively affected by increasing the SVD k-value and by increasing the maximum linking distance but positively affected by increasing the minimum track length.
Granular activated carbon sound absorption predictions made using measured material parameters
Authors: Yang Huawei , Shi Tongyang , Bolton J. S.
Published: July 2024

Granular activated carbon (GAC) is hierarchical porosity material that yields better in low frequency sound absorption performance compared with many traditional porous materials due to the sorption effect created by nanometer-scale pores within the particles. In 2017, a triple porosity model accounting for the sorption effect in the micropores was proposed by Venegas et al. In the proposed model, some of input parameters (i.e., mesopore size and micropore effective diffusion coefficient) were fitted by matching the model to measured the surface impedance of a GAC stack; however, some fitted values are questionable from an inorganic material perspective. In the present work, the GAC material parameters, such as micro- and meso-pore sizes, were estimated from a standard isotherm measurement. The measurement results showed a standard Langmuir type isotherm behavior at different temperatures: i.e., 273.15 and 293.15 K. Thus, if the isotherms can be described with the Langmuir model, then the Langmuir constant and heat of adsorption can be estimated based on the isotherms. Finally, these parameters were used as the input to the GAC model and the absorption coefficient was calculated. The calculated result was also compared with the absorption coefficient measured following the E1050 standard.
Architectural acoustics: Buildings and beyond
Authors: Woolworth David S.
Published: July 2024

Architectural acoustics not only covers buildings and the environment around them but also human perception of the acoustic environment, indoors and outdoors. As a technical committee of the acoustical society, our members are spread over research, academia, practitioners and industry. Architectural acoustics is not reserved for concert halls and opera houses but applies to all occupied spaces and has a direct impact on quality of life of any user of the space. Specific topics within the discipline include but are not limited to environmental sound, speech privacy, and speech intelligibility, simulated acoustic environments, annoyance, human hearing, airborne and structureborne noise, sound and impact isolation, loudspeakers and microphones, room acoustics, soundscape, and acoustical measurements. The technical committee on noise is often a cosponsor of specials sessions by the TCAA, as noise control via architectural means is common practice. This presentation will provide an overview of the TCAA and the field of architectural acoustics and provide examples of current research and projects of interest.
Introduction to the Technical Committee on Engineering Acoustics
Authors: Haberman Michael R.
Published: July 2024

This talk will introduce ongoing work in the Technical Committee on Engineering Acoustics (TCEA) of the Acoustical Society of America. Engineering Acoustics encompasses the theory and practice of creating tools to generate and investigate acoustical phenomena and then to apply the knowledge of acoustics to practical utility. This includes the design and modeling of acoustical and vibrational transducers, transducer arrays, and transduction materials or systems in all media and frequency ranges. It is also concerned with the design of acoustical instrumentation, metrology, and the calibration of those systems. It further considers all aspects of measurement, fabrication, and computational techniques as they relate to acoustical phenomena and their utility. The talk will provide an introduction of a broad range of research topics in TCEA, with specific highlights on exciting new areas of research.
Comparison between the performance of as-designed and as-built phononic pseudocrystal isolators
Authors: Swift S. Hales , Denison Michael , Cillessen Dale E.
Published: July 2024

Many phononic crystal studies involve fabrication of a physical object and predicting its vibrational properties and then compare these to the measured properties; however, fewer studies examine whether the differences between the as-designed and as-built versions of the finished object are relevant to its measured performance. This study considers the effects of geometric differences between as-designed and as-built phononic pseudocrystal isolators implemented in steel using laser powder-bed fusion and compares the results of measurement with simulation of the as-designed and as-built versions of the isolator to show that these differences can be significant and typically tend to degrade performance. [SNL is managed and operated by NTESS under DOE NNSA Contract No. DE-NA0003525.]
Multiple timescales of context shape the perceptual sensitivity to natural pairings of musical pitch and timbre
Authors: Stilp Christian E. , Adames Isabel , Shorey Anya E.
Published: July 2024

Musical pitch and timbre (specifically, spectral shape) covary perceptually: lower pitches are associated with darker timbres (less higher-frequency energy) and higher pitches are associated with brighter timbres (more higher-frequency energy). We examined this relationship at multiple timescales of context: trial-level (rates of performance improvement within a testing block), block-level (differences in performance across blocks), session- level (performance as a function of testing block order), and longer-term experience (musical training / background). Musical pitches were labeled as low (C4) or high (G4) from various instruments (trumpet, oboe, trombone, tuba). Testing blocks paired pitch and timbre together to either respect (Consistent) or violate (Reversed) their covariance. All timescales of context contributed to performance, producing clear patterns across experiments. Pitch labeling was poorer in Reversed blocks, but showed steeper rates of improvement than did Consistent blocks (which were often near/at ceiling levels). These patterns were moderated by which condition was tested first in the experiment and by the introduction of trial-by-trial feedback. Greater musical training was consistently correlated with higher accuracy, but adding feedback extinguished this pattern for Consistent blocks. Thus, context on a host of timescales shapes perceptual sensitivity to the natural covariance between musical pitch and timbre.
Sensitivity to spectral and temporal cues in music with a cochlear implant in single-sided deaf listeners
Authors: Galvin John J. , Lang Sean , Stupak Natalia , Landsberger David
Published: July 2024

Despite the poor sound quality with the cochlear implant (CI), single-sided deaf (SSD) CI users often prefer to listen to music with binaurally combined acoustic and electric hearing. The source of this binaural benefit is unclear. Is the benefit due to gross binaural restoration or synchronous temporal envelope information across ears? Does the detail of the spectral and/or temporal content in the CI ear matter? We investigated sources of binaural benefit for music quality in SSD-CI users by manipulating the input to the CI. Unprocessed music was presented to the acoustic-hearing ear. Experimental stimuli were delivered directly to the CI ear: unprocessed (same as everyday listening), reduced temporal modulations (using a sinewave vocoder to restrict the input to the CI), reduced spectral information (wideband noise modulated by the music temporal envelope), or wideband noise. Preliminary results suggest sensitivity to the spectral and temporal information delivered to the CI ear; however, this sensitivity was highly variable across participants. Binaural benefits were not observed when only temporal cues or white noise were presented to the CI ear. Manipulation of vocoders presented to the CI ear may be a promising approach to evaluate perception of spectral and temporal cues with the CI.
Adjusting listening effort relative to expected value of listening
Authors: Winn Matthew B.
Published: July 2024

Listening effort is a commonly reported difficulty among those who have hearing loss. A person’s ability to engage or disengage mental resources at strategic times could be an important signature of a person’s capacity to guard against wasted effort. This experiment gave listeners an opportunity to voluntarily reduce effort at specific moments based on the expected value of the incoming signal. First, sentences presented in the clear were immediately repeated, inviting reduced attention to the first presentation. In a second condition, the immediate repetition was randomly dropped on some trials, inviting increased vigilance to the first presentation. In a third condition, the first sentence was presented with degraded quality, inviting increased attention to the repetition to disambiguate misperceived words. Pupillometry was used as an index of moment-to-moment changes in listening effort. Data showed elevated pupil dilations linked in time with the disambiguated words and diminished pupil size specifically when there was less value in attending to the signal. These results support the need to expand the concept of listening effort beyond a “more” or “less” framework, toward a framework of efficiency.
The impact of hearing-aid amplification and its integrated tinnitus feature on tinnitus management
Authors: Ishida Ieda , Sun Wei , Cui Eric , Stropahl Maren , Keller Matthias , Rivera Rosario Elizabeth , Conenna Julia , Wan Celine , Dimaculangan Ivy , Hensler Stefanie , Wenhart Teresa , Qian Jinyu
Published: July 2024

Tinnitus is the potentially debilitating perception of phantom sound with no current cure. Although some management approaches are available, the benefits of hearing aid amplification and its added noiser are uncertain. This study assessed impacts of hearing-aid amplification, and amplification with an added noiser feature, on adults with hearing loss and chronic bothersome tinnitus. Thirty adults [42–75 (Mean = 61.1) years old; 18 males], with mild to moderate sensorineural hearing loss but no previous amplification exposure; and bothersome tinnitus [Tinnitus Functional Index (TFI) baseline scores of at least 20], were randomly assigned to one of two groups in a cross-over study to experience amplification-only, and amplification + noiser for one month each, following one month of no intervention. Study hearing aids were worn minimally for 5-h/day. TFI questionnaires evaluated tinnitus severity before and after each condition. A one-way repeated measures ANOVA with 30 participants revealed a significant effect on TFI across baseline, amplification-only, and amplification + noiser conditions (p = .023), suggesting tinnitus improvement across conditions. Further post-hoc tests indicated lower TFI scores in the amplification + noiser condition (p = 0.048), identifying its distinct benefit. Preliminary analysis suggests benefit of hearing aid amplification, with a prominent advantage of the noiser feature on tinnitus management.
Visual cues influence prosody perception among individuals with cochlear implants
Authors: Fleming Justin T. , Wheeler Harley J. , Winn Matthew B.
Published: July 2024

Understanding a talker’s intention conveyed through prosody is essential for successful speech communication. Although visual speech cues are typically characterized by lip movements, there are also visual gestures including head tilts and eyebrow raises that signal prosody. Listeners with cochlear implants (CIs) may rely on these visual cues to solidify their prosody perception and guard against misinterpretations, particularly because of their poor perception of voice pitch. This study used audio-visual recordings of sentences in which a talker sometimes focused one word to signify a change in meaning. After characterizing acoustic and visual prosody cues in this stimulus set, we made prosodically mismatched variants of the stimuli by transplanting prosodically focused audio onto broad focus (i.e., prosodically unfocused) video, and vice versa. Visual influences on prosody perception were measured using acoustic analysis of participant reproductions in a vocal mimicry task. Results show reproduction of F0 contour—a key acoustic marker of prosodic focus—is influenced by perception of visual prosody cues. Specifically, visual cues indicating a focused word led to higher peak F0 in vocal reproductions of that word in the sentence. These results underscore the importance of multisensory information in supporting prosody perception for listeners with hearing loss.
Feel sounds with your hands: Exploring tactile frequency-following response
Authors: Sharp Andreanne , Belen Carbajal Chavez Ana , Chauvette Loonan , Zatorre Robert , Coffey Emily
Published: July 2024

Auditory perception is often influence by other senses. Prior studies have documented that the auditory cortex can respond to vibration, but the nature of this neural response remains unclear. The frequency-following response (FFR) is a non-invasive evoked brain response that can be used to study the fidelity of periodicity encoding of complex sounds. The main goal of this study was to investigate if tactile processing of sounds retains periodicity information as measured by the FFR. We acquired electroencephalography while participants were presented with repetitions of a synthesized speech syllable /da/ under three conditions (Auditory, Tactile, and both). A technology developed within our laboratory (Multichannel Vibrotactile Glove) was used to present sounds to all fingers. Results reveal that it is possible to measure a tactile FFR using vibrotactile stimulation, which is similar to the auditory FFR, but exhibits somewhat different characteristics as compared to unimodal auditory FFR, including lower amplitude and no sensitivity to harmonics. These findings suggest that these modalities interact, opening up questions about the origins and pathways responsible for the phenomena and introduces potential uses of tactile perception to mitigate the effect of hearing loss in speech and music perception.
Ocean sound speed field reconstruction beyond tensor neural network
Authors: Cheng Lei , Li Siyuan , Chen Panqi , Zhang Ting , Li Jianlong
Published: July 2024

Obtaining accurate ocean sound speed fields (SSFs) across a three-dimensional (3D) geographic region is vital for various underwater acoustic tasks. However, the scarcity of measurements due to the high cost of underwater sensors, combined with the high dimensionality of complex 3D SSF, makes the reconstruction problem highly ill-conditioned, thus demanding advanced models and methods. Our recent work has analyzed the reconstruction error and identified one promising way: finding a representation model that is both concise and expressive. Following this path, we proposed a tensor neural network (TNN) model, which leverages the conciseness of tensor models and the expressive power of deep learning. However, existing TNN-based approaches have two limitations: (1) they are unable to capture long-range correlations within the SSF and (2) they can only handle discrete-indexed tensor data. To overcome these limitations and fully unleash the power of deep tensor learning, we seamlessly introduce attention schemes into the existing TNN framework without compromising its interpretability. Additionally, we employ Gaussian process models to evolve the original parameterized tensor model into a new functional tensor model, enabling reconstruction with a continuous grid. Numerical results obtained from real-life datasets demonstrate the superior performance of our approach compared to state-of-the-art methods.
Exploiting passive acoustic recordings of seismic survey datasets
Authors: Douglass Alexander S. , Abadi Shima
Published: July 2024

Marine seismic reflection surveys provide a dense and abundant dataset covering a large region of geological interest in the ocean. These data provide an opportunity for acoustic analysis with varying environmental characteristics, both in the water column and the seabed. In a typical survey, an airgun array is fired tens to hundreds of thousands of times, and hundreds of receiver channels record the acoustic signal reflected from the seabed after each shot. Additionally, the high amplitude signal broadcast from airgun arrays used in these surveys may be measured passively by hydrophones located close to the survey. In this work, we consider the data measured by Ocean Observatories Initiative (OOI) hydrophones adjacent to two seismic surveys, MGL1905, and MGL2104. In each case, a 6600 in3 airgun array is fired ∼every 37.5 m along multiple survey lines extending 10s to 100s of kilometers. Each survey generates multiple terabytes of acoustic data, and many of the shots are also captured by OOI hydrophones. This work aims to combine these two datasets to evaluate the acoustic behavior of airgun shots over a variety of conditions and examine the relationship between various environmental factors and acoustic propagation behavior. [Work supported by ONR.]
Analysis of gas evolution in the heart, liver, and kidney of turtles presenting with gas embolic pathology based on ultrasonography
Authors: Eltz Katherine M. , Crespo Jose-Luis , Azarang Arian , González Emma , Garcia Daniel , Fahlman Andreas , Papadopoulou Virginie
Published: July 2024

Human-caused disturbances of sea turtles can result in them presenting with gas embolic pathology which often leads to severe injury or death. While gas embolism has been previously observed in turtles using MRI and x-ray/CT, as well as ultrasound to a lesser degree, how the distribution of gas evolves in different organs over time, and its possible correlation to outcome, is poorly understood. We hypothesize that ultrasound imaging of the heart, kidney, and liver over time can help differentiate pathology resolution or worsening trajectory and may help refine veterinarians’ treatment algorithm in this population. The liver, kidney, and heart of 100 by-caught turtles were imaged, and gas amount in each ultrasound scan was graded on a scale from 0 (no gas) to 5 (gas completely shadowing organ anatomy). Turtles scanned on the boat had higher grades in all organs compared to turtles first scanned at shore which was on average 163 minutes later. Average pixel brightness in the top half of cardiac scans increased with grade as expected, apart from grade 5 likely due shadowing. Ultrasound brightness could become a quantitative metric for veterinarians to determine which turtles need hyperbaric oxygen treatment and which can be released.
Contrast-free microvessel imaging using null subtraction imaging combined with harmonic imaging
Authors: Kou Zhengchang , Miller Rita , Oelze Michael L.
Published: July 2024

Ultrasound localization microscopy (ULM) has superior spatial resolution; however, it requires contrast agents and long data acquisition and processing time. Null subtraction imaging (NSI) is a nonlinear beamforming technique that improves the spatial resolution and reduces grating lobes with low computational cost. We combined pulse-inversion (PI) nonlinear imaging with NSI to increase resolution. Pulses with center frequency of 10.42 MHz and its inverted version were transmitted to obtain the second harmonic at 20.84 MHz (wavelength of ∼74 μm). The transducer pitch was 35% larger than the wavelength of the receive signal, which would introduce grating lobes in the field of view. A total of 1000, 9-angle (−8 to 8 degree in 2 degrees step) coherently compounded frames were acquired in 1 s. SVD filters were applied in raw RF data to filter out tissue signal. The dc offset was set to 0.1 in NSI imaging. Grating lobes, which were obvious in DAS images, were removed in the NSI images. Higher spatial resolution and contrast were observed from the NSI microvessel images. The spatial resolution of the NSI images using harmonic imaging approached one fourth of a wavelength with computation time increased by only 40% compared to DAS.
Directional wave spectrum evolution modelling of ship noise
Authors: Brown Michael G.
Published: July 2024

A new underwater acoustic propagation model that is well suited to modelling ship noise is described. The model describes the spatio-temporal evolution of the directional energy spectrum of a sound field. The governing equation can be thought of as an advection-diffusion equation for spectral energy in phase space (position, angle). Numerical simulations of sound fields excited by both isotropic compact sources and by highly anisotropic ship noise provide confidence that the model works well, with caveats that will be discussed. [Work supported by ONR.]
Sound attenuation performance at high sound pressure level of micro-perforated panel sound absorber with embedded resistive screen
Authors: Laly Zacharie , Atalla Noureddine
Published: July 2024

In this paper, a composite sound absorber made of a micro-perforated panel (MPP), an air cavity with embedded resistive screen and a rigid back plate is investigated at high sound pressure level (SPL). The sound absorption coefficient predicted theoretically is compared with the experimental measurement at 150 dB and a good agreement is obtained. It is demonstrated that the incorporation of resistive screen within the air cavity improves significantly the sound absorption that presents a large frequency band and remains almost identical with respect to the SPL compared to a classical MPP absorber whose sound absorption peak varies with the SPL. The MPP absorber with the resistive screen glued on the MPP is studied and different resistive screens are compared at 150 dB and it is observed that the sound absorption coefficient increases with a large frequency band, which depends on the airflow resistivity of the screen. A sensitivity analysis shows that the resistance per unit area of the screen affects the acoustic properties of the absorber at low SPL while at high SPL, the acoustic properties are mainly controlled by the perforation ratio of the MPP and the acoustic orifice Mach number.
Long-range electrostatic forces in periodic structures: The development of adjustable wave filters
Authors: Farzbod Farhad
Published: July 2024

In this work, we examine the effects of electrostatic forces on wave propagation in periodic structures. The research explores how these structures, a type of metamaterial, can have their vibrational characteristics altered by interactions that are non-local. In this work, it is demonstrated how electrostatic forces influence dispersion curves and the resultant metamaterial properties. These findings have implications for developing tunable metamaterials, with potential applications in various fields, such as tunable wave-beaming devices and filters. This research contributes to a deeper understanding of the complex interactions in metamaterials and their practical applications.
Statistical correlations between construction parameters and radiated sound in a set of professional-level violins
Authors: Gonzalez Sebastian , Kwan Mary Jane , Antonacci Fabio , Zygmuntowicz Sam
Published: July 2024

Violin making is perhaps one of the most mysterious crafts in the western tradition of instrument making. The current approach to crafting musical instruments relies heavily on intuition and accumulated knowledge, transmitted through generations in a traditional master-apprentice format. The extended time required for both instrument creation and the development of the skills and intuition essential for this craft makes the learning process highly time-consuming. The fundamental question in violin making is how construction and material parameters influence the acoustic response of the instrument. By analyzing data recorded for over 20 years of career, we are able to obtain strong correlations between material, design and acoustic characteristics for a set of instruments by the same maker. This is, to the best of our knowledge, the most complete dataset in the world. Applying least square fitting to the power emitted by the violins in different bands, we are able, for the first time, to find statistically significant correlations between construction parameters and acoustic response in a set of professional-level instruments.
Timbral effects of col legno tratto techniques on bowed cello sounds
Authors: Pàmies-Vilà Montserrat , Saitis Charalampos
Published: July 2024

There are several playing techniques for bowed-string instruments that make use of the wooden stick of the bow. The stick is quite often used to strike the strings gently (col legno battuto) and less commonly to bow on them (col legno tratto). Col legno has existed since the 17th century, and it is often used in modern compositions. When the stick is drawn across the string (tratto), the contact between the scrubbing stick and the string introduces noise. The player may choose to combine both hair and stick, depending on the desired sound. To evaluate the timbral effects of col legno tratto on the cello sound, the current study compares three variations across ordinary and contemporary bowing techniques: using only the hair, using both hair and stick, and using only the stick. Motion capture and audio-video recordings with expert cello players show how the bow tilt varies greatly between the three cases. Suitable audio descriptors of timbre are evaluated, which may help to correlate the observed playing parameters and sound properties with the semantic attributes used by experts to describe the timbre of these techniques.
Development of a far-field prediction model for tactical jet noise spectra
Authors: Pratt Hunter J. , Mathews Logan T. , Gee Kent L.
Published: July 2024

Semi-empirical models for predicting far-field jet noise radiation are computationally efficient. One historical example is NASA SP-8072 (1971), which couples source sound power spectra with frequency-dependent directivity indices to obtain far-field radiated spectra for rockets. This paper applies the SP-8072 framework to develop spectra for the T-7A trainer aircraft. Data at 38 and 76 m arcs are used to obtain sound power spectra and frequency-dependent directivity indices for four different engine conditions ranging from 36% thrust through maximum afterburner. Application of a ground reflection correction model is discussed. The model is applied to obtain results at distances between 19 and 229 m and the performance of the model is evaluated using measured data. [Work supported by ONR Grant No. N00014-21-1-2069.]
Comparison of two acoustic test fixtures for measuring impulse level dependent attenuation
Authors: Murphy William J. , Flamme Gregory , Tasko Stephen M. , Deiters Kristy K. , Meinke Deanna K. , Finan Donald S. , Lankford James E. , Stewart Michael
Published: July 2024

In the American National Standards Institute (ANSI) S12.42-2010 standard for measuring insertion loss of hearing protection devices (HPDs) in impulsive noise, the range of peak sound pressure levels for the impulses is 132 to 168 dB peak sound pressure level (dB pSPL). The specification of the acoustic test fixtures (ATFs) included an IEC 60318-4 ear simulator fitted with a microphone. The microphones typically used are a ¼” cartridge and have a dynamic range up to about 169 dB pSPL. For most small caliber firearms, the peak SPLs are less than 170 dB SPL at the location of the shooters ear (Schulz et al. 2013). For some military weapon systems that produce impulses greater than 170 dB pSPL, impulse insertion loss cannot be assessed without exceeding the microphone maximum dynamic range. Some condenser microphones have maximum dynamic ranges of 190 dB pSPL. This paper compares insertion losses for HPDs measured on two GRAS 45CB ATFs with microphones with maximum dynamic ranges of 169 and 193 dB pSPL. Waveform distortion, field probe to unoccluded transfer functions between the ATF and field probe will be examined for distortion and accuracy when estimating the impulse level dependent attenuation.
Development of a biofidelic acoustic test fixture and evaluation in impulsive noise
Authors: Wilbur Jed C. , Graybill Brian , Clavier Odile
Published: July 2024

Here, we describe the development and use of a novel biofiedlic head surrogate for evaluating head and hearing protection devices against impulsive, shock, and blast insults. The head surrogate, derived from biomedical imagery, includes biofidelic pinnea, ear canals, and skull. In addition to microphones positioned at the ear canal terminus, the surrogate includes accelerometers and a hydrophone to provide an estimate of sound propagation through the bone-conduction pathways. This allows use of the surrogate to estimate a device's ability to attenuate bone-conducted pressure waves. We discuss the tradeoffs between biofidelity, manufacturability, instrumentation, and cost. We will show example data from various test campaigns, including the estimating the attenuation of the bone-conduction pathway afforded by different helmet systems during a 178 dB SPL (peak) shock insult. We will conclude with a look towards the future, including potentially updating the underlying three dimensional models to align with modern biomedical models and databases.
Toward a standard for assessing civilian firearm suppressor noise reduction: Environmental and procedural considerations
Authors: Tasko Stephen M. , Murphy William J. , Flamme Gregory , Deiters Kristy K.
Published: July 2024

Currently, no consensus standard exists for measuring firearm suppressor noise reduction (FSNR). NATO developed a military standard to measure suppressor performance for an environment that does not generalize well to the recreational shooter. We propose a FSNR measurement standard using maximum accumulated A-weighted energy. Test environments included an outdoor space and a reverberant (indoor) facility with dimensions expected to provide similar results to the outdoor space. Two standard test barrels (0.308 and 0.223 caliber) mounted on a universal receiver system were used. For each environment and caliber, two ammunition types and three suppressors were tested, along with an unsuppressed condition. Ten discharges were recorded for each condition. Five field microphones were positioned at four locations around the universal receiver. Impulses in quasi-free field and reverberant environments are compared and the impact of combustion gases within the suppressor and the number of discharges to achieve stable estimates of noise reduction are considered. Similar FSNRs were observed in the environments. Clearing the suppressor of combustion gases had variable effects on impulse level, and relatively stable estimates of suppressor attenuation were achieved with seven test discharges.
Military health system auditory blast injury prevention standard
Authors: Brokaw Elizabeth B. , Gupta Raj K. , Spencer Rachel , Lalis Lisa
Published: July 2024

The Department of Defense (DoD) lacks a single medical standard for prevention of auditory blast injury, relying on the Service Branches to develop their own guidance. The DoD Executive Agent established the Blast Injury Prevention Standards Recommendation (BIPSR) process, led by the DoD Blast Injury Research Coordinating Office (BIRCO), to investigate the effects of blast injuries on warfighters. The BIPSR Process implementation of the Auditory Blast Injury Type illuminated characteristics, capabilities, and limitations of current capabilities to predict and prevent auditory injuries. The evaluation resulted in the recommendation of 8-h Equivalent Level (LAeq8hr) as the interim MHS Auditory Blast Injury Prevention Standard to serve as the cross-Service standard while the community performs additional research to fill critical knowledge gaps. BIRCO is working to formalize the Military Health System Auditory Blast Injury Prevention standard to support updates and coordination across DoD guidance including military design standards and health protection policies.
Revising normative standards for personal noise dosimeters
Authors: Hanes Peter
Published: July 2024

Personal noise dosimeters are designed to monitor noisy environments and are usually intended to attached to an individual person in order to estimate their exposure to noise over a given period of time. These devices are often used to indicate sound exposure as a percentage of a predetermined criterion. However, different jurisdictions employ different definitions of such quantities and different criteria for permissible exposure. Therefore, existing normative standards for measurement instruments differ in their specifications. For example, while the ASA/ANSI S1.25 standard Specification for Personal Noise Dosimeters makes provisions for use of three level-time exchange rates (3, 4, and 5 dB per doubling of exposure time), the international standard for personal sound exposure meters (IEC 61252) permits only an exchange rate of 3 dB. The International Electrotechnical Commission is revising IEC 61252 to modernize and harmonize requirements for the instruments to reflect the actual practice of measurements of noise exposure worldwide. The technical aims of the revision are to provide realistic specifications, consistent methods for testing all relevant characteristics of a model of instrument, and affordable methods for periodic testing of individual instruments. Potential consequences of the likely changes to IEC 61252 are presented and discussed.
Utilizing Near-Ultrasound Inaudible Trojan (NUIT) to compromise microphone security
Authors: Chen Guenevere (Qian)
Published: July 2024

Voice Control Systems (VCSs) provide a user-friendly interface for issuing voice commands to smart devices. However, the security of VCSs remains a challenge, as evident from two distinct attack classes: (i) inaudible attacks, feasible when the attacker is in proximity to the victim, and (ii) audible attacks, which can be executed remotely by embedding attack signals into audio. In talk introduces a novel class of attacks known as Near-Ultrasound Inaudible Trojan (NUIT). NUIT attacks combine the advantages of both classes, being both inaudible and capable of remote execution. Additionally, NUIT attacks can achieve end-to-end unnoticeability, a crucial aspect often overlooked in the literature. Notably, NUIT attacks leverage victim speakers to compromise victim microphones and associated VCSs, eliminating the need for specialized speakers. The feasibility of NUIT attacks is demonstrated, and an effective defense against them is proposed.
Estimating infrasonic noise levels using a high resolution weather model
Authors: Assink Jelle D. , Smink Madelon , Bosveld Fred , Evers Läslo G.
Published: July 2024

The presence of turbulence and other wind-induced pressure fluctuations are considered a nuisance in infrasound monitoring. For this reason, wind noise filters are typically in place for suppression. In this study, we establish a relation between microbarometer observations and in situ turbulence measurements at the Cabauw Atmospheric Research Site in The Netherlands. Using this relation, we forecast turbulent pressure levels using forecasted levels of turbulence kinetic energy (TKE) that are computed as part of the high-resolution (2.5 × 2.5 km grid scale) HARMONIE weather model. The estimates are compared with pressure noise levels as a function of frequency. This approach has two foreseen applications: (1) the forecasted turbulence fields could possibly help in site selection for infrasound arrays and (2) microbarometer observations could possibly be of use in the further refining of sub-grid scale turbulence schemes in weather models.
Seismometers as infrasound sensors
Authors: Costley Richard D. , McComas Sarah , Simpson Christopher , Hayward Chris , McKenna Mihan
Published: July 2024

An experiment was conducted in West-Central Mississippi in which five explosive charges were detonated. The TNT equivalent sizes of the charges ranged from 0.57 to 10.91 kg (1.25 to 24 lb). Among the arrays of sensors deployed, seismometers were deployed near microphones at distances of 0.5, 2.1, and 8.4 km from the source. The blast wave at these distances had decayed in amplitude to an acoustic wave. The coherence between the seismometer and microphone signals showed that the seismometer provided reasonable representation of the acoustic wave over limited frequency bands; however, these bands changed between sensor locations. In addition, two 3-component seismometers were deployed near each other 8.4 km from the source. These seismometers were of different types, one having a resonance frequency of 1 Hz and the other at 4.5 Hz. The signals from the horizontal components of these seismometers were analyzed to determine their effectiveness as vector sensors. The results showed that the back-azimuth determined from the seismometers agreed reasonably well with ground truth for the first arrival of the acoustic wavefront; however, the results degraded as the trailing part of the wavefront passed. Permission to publish was granted by the Director, Geotechnical and Structures Laboratory.
Auditory processing in neurodiverse children
Authors: Lau Bonnie K. , St. John Tanya , Estes Annette , Dager Stephen
Published: July 2024

Many neurodiverse individuals experience auditory processing differences including hyper- or hyposensitivity to sound, attraction or aversions to sound, and difficulty listening under noisy conditions. However, the origins of these auditory symptoms are not well understood. In this study, we tested 7-to-10-year-old autistic children and age and sex-matched neurotypical comparison participants. To simulate a realistic classroom situation where many people are often speaking simultaneously, we obtained neural and behavioral measures of speech perception in both quiet and noise conditions. Using electroencephalography, we recorded neural responses to naturalistic, continuous speech to assess the cortical encoding of the speech envelope. We also obtained behavioral multitalker speech perception thresholds and estimates of spatial release from masking, a binaural hearing phenomenon in which speech perception improves when distracting speakers are spatially separated from the target speaker. Our preliminary results from both neural and behavioral measures suggest that the autistic group shows worse speech perception in noise and less spatial release from masking than the neurotypical group. These findings suggest that autistic children may benefit from environments with reduced noise to facilitate speech perception. These findings also warrant further investigation into speech perception under real-world conditions and the neural mechanisms underlying sound processing in autistic children.
Perceptual training facilitates Mandarin tone production for preschoolers with cochlear implants: Evidence from acoustic analysis
Authors: Zhang Hao , Xu Lele , Ma Wen , Ding Hongwei , Zhang Yang
Published: July 2024

This study primarily aimed to investigate the benefits of an established perceptual training in the production of lexical tones for Mandarin-speaking preschoolers with cochlear implants (CIs). Thirty-two pediatric CI recipients were tested in this study. Half of the child participants received five sessions of high variability phonetic training (HVPT) within a period of three weeks, whereas the other half served as control who did not receive the formal training. Production of Mandarin tones was recorded before the provision (pretest) and after (posttest) the completion of the training protocol, which was coded and analyzed acoustically with automatic pitch tracking implemented in the software of Praat. Results showed significantly enhanced concave characteristic of dynamic pitch contours for the trained children’s Mandarin tones produced in posttest relative to pretest using growth curve analysis. Moreover, a tonal ellipse analysis indicated significantly improved tone differentiability and tone hit rate from pretest to posttest following training. By contrast, no significant changes were observed in the control children between the two test sessions. The findings represent initial acoustic evidence of HVPT-induced benefits in lexical tone production for CI users, which supports the application of this perceptual training protocol to aural rehabilitation practice.