bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluating numerical techniques with HPC systems in predicting vibratory responses of large finite element models
Authors: Bennett Alyssa , Flores Hector , Wu Kuangcheng , Wong Steve , Bonomo Anthony L.
Published: April 2023

Finite element (FE) analyses have been widely used to support design optimizations in various disciplines to improve performance and possibly save material, cost, and schedule. As computational resources (i.e., CPU, memory, storage, and accelerator) are getting more powerful and cost effective, the complexity and model sizes of numerical models are greatly increasing to capture geometry details and features of the design. Correspondingly, the computational time for complex and large FE models are significantly growing. Traditional brute-force approach is not quickly enough to support design iterations. In this presentation, various numerical techniques are investigated and exercised in the DoD High Performance Computing systems to identify their advantages and limitations in conducting large FE analyses. Those techniques include utilization of GPGPU, direct versus iterative solvers, approximation of frequency sweep, etc. As a benchmark case, frequency response functions of a flat plate with viscoelastic material is exercised at the DoD HPC systems to examine the numerical techniques' impacts.
Low-frequency acoustic rotorcraft classification
Authors: Ochi Gordon M. , Blevins Matthew G.
Published: April 2023

Rotorcraft emit unique acoustic signatures tied primarily to their blade pass frequencies. In this study, we examine the ability of artificial neural network machine learning methods to successfully classify several distinct types of rotorcraft based on their low-frequency acoustic signatures. Time series, power spectral density, and Welch power spectral density input types are examined, corresponding to convolutional neural networks for the first input type, and multi-layer perceptrons for the latter two input types. A K-fold cross-validation is used to initially assess the generalization performance of the various models, along with confusion matrices for a deeper dive into the model performance. Ablation studies are discussed for insights into model behavior. These insights are used to showcase further enhanced neural network models with increased robustness and accuracy.
Capturing the sounds of the stratosphere using solar hot air balloons
Authors: Bowman Daniel , Albert Sarah , Krishnamoorthy Siddharth , Hough Emalee , Yap Zach , Silber Elizabeth , Lees Jonathan
Published: April 2023

Low frequency sounds can travel vast distances across the planet, carrying information about the events that generated them as well as the medium through which they travel. These sounds are usually recorded on surface-based sensors. Recently, however, sensors have been lofted on high altitude balloons, where they have revealed a rich soundscape quite different than that of the Earth’s surface. Here we describe acoustic observations of the lower stratosphere conducted using inexpensive microbarometers lofted via passive solar hot air balloons. We discuss background noise as well as individual events, some of whose origins remain enigmatic. We delve into how to carry out an acoustic sensing mission using our instrumentation and flight system. Finally, we outline future directions for this technology, including deployment on extraterrestrial bodies such as Venus. [SNL is managed and operated by NTESS under DOE NNSA under Contract No. DE-NA000352.]
Measurement of electroacoustic transducer sensitivity in extreme hydrostatic pressure environments
Authors: Brown David A. , Aikins Eric K.
Published: April 2023

The measurement and acoustic calibration of electroacoustic transducers for underwater sound under extreme pressures (to 10,000 psi / 7km depth) and variety range of temperatures is a great challenge. Specialized facilities consisting of large pressure vessels with pressure and temperature control do exist at Navy faciliites (www.navsea.navy.mil + USRD) but operate to moderate pressures, have limited availability, are expensive and limited access. An alternative or supplement is to measure the change in the electro-mechanical impedance of the of a transducer and use equivalent electrical cirucuit analysis to determine the resulting change in all electrical, electromechanical, and mechanical properties. Having the pressure and temperature depedence of all the consitutent parameters allows an accurate pediction of the transduer performance sensitivity and frequency response (such as TVR Transmit Pressure per Volt, and receive voltage per pressure sensitivity. We measured transducer performance of several devices in the laboratory pressure vessels up to 10 000psi and report on findings.
AudioMoth adventures: How does a low-cost recording device perform in extreme environments?
Authors: Wolek Nathan
Published: April 2023

When it was originally released in 2018, the AudioMoth acoustic recording device delivered an attractive new platform for passive acoustic monitoring. With a price point under 100 US dollars, a size smaller than a deck of cards, and open-source software, the AudioMoth is an exciting option for getting started with bioacoustics monitoring. However, these same features often invite skepticism from those who have never used it. How good is the recording quality from its tiny MEMS microphone? How does it hold up to extreme outdoor conditions? The addition in 2022 of the HydroMoth for underwater recording, only invited more questions about its ability to perform in extreme environments underwater. This presentation will offer personal reports of the author's own experiences using the AudioMoth and HydroMoth. It will also include original field recordings captured in extreme environments like strong winds, heavy rains, and salt water lagoons. Special attention will be given to the two hurricanes that hit Florida in 2022, which were both captured by the author during a HydroMoth deployment. The audience will leave with a better idea of what to expect from the AudioMoth platform should they consider using it for their own projects.
Ultrasonic damage detection in lithium-ion cells with localized thermal abuse histories
Authors: McGee Tyler , Neath Barrett , Matthews Samuel B. , Ezekoye Ofodike A. , Haberman Michael R.
Published: April 2023

Electric vehicles require nearly 1000 individual lithium-ion batteries to provide appropriate power and capacity. It has recently been shown that ultrasonic inspection can detect localized heating in a LIB cell with a combination of input frequencies and propagation paths [J. Acoust. Soc. Am. 152, A283 (2022)]. However, monitoring the thermal conditions of every cell in a battery pack is highly challenging to implement. This work explores the use of ultrasonic inspection to diagnose LIB cells with damage histories due to local, thermal abuse. LIBs were interrogated with ultrasonic waves while subjected to electrical and thermal loading, specifically, standard charge-dischargecycling followed by moderate localized thermal abuse and another phase of charge-discharge cycling. Ultrasonic signals from each portion of the test and data for the cycling before and after heating are directly compared for indicators of past abuse. Experimental data are compared to a transfer-matrix model to simulate the time-of-flight (TOF) through an individual cell using temperature-specific material properties for individual components to simulate the effect of heat on TOF. Experimental results indicate that deviations in time-domain features of the received signals can be used to detect previous thermal abuse via ultrasonic testing during charge-discharge cycling after thermal abuse.
Percussion instruments and their relationship to well-known structural radiators
Authors: Shepherd Micah
Published: April 2023

Several structural radiators have been well studied in the past century and are commonly used to illustrate principles of structural-borne acoustic radiation. These structural radiators include the membrane, thin beam and thin plate. The principles of vibration and acoustic radiation of these radiators will be overviewed in terms of their normal modes. The standard assumptions which allow these structures to be useful in illustrating general principles of structural acoustics will also be outlined. The relationship of common percussion instruments to these structural radiators will then be presented with emphasis on which of the previously discussed assumptions hold for each instrument and which assumptions do not. Modern methods for studying the vibration and acoustic radiation of these instruments will then be outlined.
Characterizing the vibrational behavior of steelpans with a reduced number of notes
Authors: Morrison Andrew C.
Published: April 2023

The skilled artisans who construct lead (tenor) steelpans generally attempt to tune the first three resonances of each note harmonically. When successful, the tuning leads to neighboring notes sharing the same frequency for the first two harmonics of each note on the outer ring of the steelpan. The sympathetic excitation of the neighboring notes is believed to contribute significantly to the unique timbre of the steelpan's characteristic sound. A series of custom steelpans with fewer notes was commissioned to understand better the nature of the coupling between the struck note and sympathetically vibrating notes. Electronic speckle pattern interferometry was used to compare the coupling between notes on standard tenor steelpan with the coupling between notes on the customized steelpan having fewer notes.
Environmental noise modeling: A case study near the busiest airport in the world
Authors: Clements Jessica S. , Garretson John
Published: April 2023

This case study examines modeling and measurements taken at a project site in Atlanta, Georgia. The site is an expansion of a movie studio to encompass 18 new large sound stages, 8 fixed stages, and support spaces. The site is located just inside the Atlanta I-285 perimeter and directly under a major flight path from Hartsfield Jackson Atlanta International Airport. The studio includes 8 existing sound stages located 3 miles from the expansion. Both long term and short term measurements were take and used to confirm the environmental noise modeling. Modeling was used to predict the impacts on the site and inform the building shell design. At late stages of the project, the Department of Transportation purchased land adjacent to the site and planned to regrade and move a major exit ramp closer to the site. This case study will review the multiple challenges of the project and the environmental noise modeling performed. The project is on-going and not in construction.
Validation of sound propagation from outdoor music venues—A comparison of measurement and models
Authors: Woolworth David S.
Published: April 2023

The post pandemic United States has seen a surge in new outdoor entertainment venues springing up with various levels of planning in regard to sound impact on communities. The variability of sound systems, artists, audio engineers and operators, low frequency content ratios, and weather conditions beg the need to predict potential impact of venues on communities and understand what sound management is possible. Two venues will be shown with controlled sound system tests measured compared with propagation computer models. In addition, iterative design efforts with architectural noise control to reduce impact on the nearby community will be shown, in particular an attempt to reduce low frequencies and the limits of modeling standards in regard to diffraction.
Comparison of soft ground and miscellaneous attenuation in pastureland of the American West
Authors: Miller Robert D.
Published: April 2023

Environmental noise measurements were performed in American West pastureland including incremental measurements over soft ground and miscellaneous attenuation through thick willow brush. Measurements will be compared with standard prediction methods such as ISO 9613. Additional distant highway measurements complimented by an ambisonic microphone will also be discussed.
Verification of an acoustic model of outdoor sound propagation from a natural resource compressor station over complex topography
Authors: Phillips James E.
Published: April 2023

Outdoor sound propagation from a natural resource compressor station with multiple, large, reciprocating compressors enclosed within a structure was modeled using DGMR iNoise. Data from sound level measurements taken near the station were used to estimate the sound power of the operating compressor station equipment and used as input to the model. The model was then used to project the sound pressure levels at multiple measurement locations over complex topography. Good agreement was achieved between the projected and measured sound pressure levels as far as ½-mile from the station, particularly after accounting for meteorological influences upon sound propagation in the field. Observations and lesson learned while measuring and modeling the sound propagation will be discussed.
Validation of environmental noise models from a manufacturer's persepctive
Authors: Smith David J. , Notario Antonio
Published: April 2023

Validation is a critical part of the modelling process. Without this stage, it may be impossible for users to tell how close their model is to the real world. Validating an environmental noise model can be tricky, but there are some important ideas to keep in mind that can help you. DataKustik, the developers of the environmental noise prediction software CadnaA, and Scantek, Inc., the sole distributor of DataKustik products in North America, would like to offer some dos and don’ts of validating an environmental noise model from a manufacturer’s point of view.
Environmental noise modeling, quality control, verification, and validation concepts
Authors: Forschner Hans J.
Published: April 2023

Over the past 30 + year's noise modeling has developed in all engineering fields. ISO 9001 has developed detail simulation validation criteria's for variouse engineering fields. Engineering software application for environmental noise modeling are just one of many fields that offer advanced simulation options. Unfortunately, the validation of environmental noise simulation is still under development. With the increase of environmental noise projects the model validation between test and simulation is scrutinized by the public or in court. The presentation discusses the definition of Model, Mathematical Model, Computational Model and Conceptual Models and the definition of Verification, Validation and Updating. What are the tools for quality assurance (QA) for the noise modeling software, software verification and project quality control (QC)? What is the state of noise modeling standards in North America? What are the uncertainties and variabilities that the environmental noise engineer can control? Are we sure that we are modeling a worst-case scenario? What can consultants do to improve the quality of noise simulations.
Managing community noise impacts from blasts
Authors: Manuel Gethin , Waddington David
Published: April 2023

The aim of this work is to examine noise impacts at long range from a variety of blast and explosion testing. This work forms part of an ongoing collaborative research project on blast noise supported by DNV and carried out at their Spadeadam Testing & Research site in the UK. The site carries out full-scale major hazards research to support safety concerns associated with industry decarbonization sectors and protect people and property from accidental and intentional threats. The diversity and novelty of blast testing involve a variety of source characteristics that need to be understood to make predictions of long-range environmental noise at off-site residential and recreational locations. Range-dependent ground impedance and complex topography surround the site, and local meteorological features are difficult to predict in advance of testing, leading to difficulties in making long-range sound predictions via computational methods. Presented here is a data-driven heuristic method developed upon a database of off-site noise measurements and meteorological data. It is concluded that meteorological forecasts can be used to make useful predictions of noise from a variety ofblast testing at long-range receivers. It is proposed that further measurements at additional receptor points are made to improve the performance of the model.
Assessment of sound propagation for the urban air mobility
Authors: Malbéqui Patrice R.
Published: April 2023

The noise generated by vertical takeoff and landing vehicles (VTOL) operating in urban environnement is a determinant factor for the community acceptance. The ray-tracing method used for predicting road and raylway noise in urban areas can also be applied to the Urban Air Mobility context. In densely populated urban area, the multipath of sound wave occurs due to numerous reflections on the buildings walls. Such a configuration generates both constructive and destructive interferences, given rise to a complex shape of the spectra, that can be difficult to explain. To assess ray codes dedicated to road noise for this kind of configurations, simple test cases such as a corner and a canyon based on image sources are proposed. The prediction is performed in octave bands in the frequency range 63 Hz to 8000 Hz, including acoustical source at high altitudes to account for the VTOL flight. A good agreement is found between the reference solution derived from the image-source and the ray tracing technique. In particular close to the corner a significant increase of about 9 dB can be found. When both the source and the microphone are in the canyon, an inscrease up to 14dB can be found.
Turbulence effects on shaped booms: Finite impulse response filter development
Authors: Downs Robert , Barzach Michael , Klos Jacob , Lonzaga Joel B. , Doebler William , Parker Peter A. , Loubeau Alexandra
Published: April 2023

Numerical simulations of propagation through turbulent atmospheres can quantify effects on ground waveforms, but such simulations are computationally expensive. To enable quick turnaround analyses as required by NASA’s Quesst Mission, updating the N-wave filtering approach developed by researchers at The Pennsylvania State University to include shaped booms is proposed as an alternative method for estimating turbulence effects on acoustic metrics more quickly. Beginning with a nearfield pressure cylinder modeled after the on-design X-59 configuration, a database of propagation results at 45 turbulence conditions was compiled using nonlinear turbulence propagation modeling code (KZKFourier) and used as input to a process for generating finite impulse response (FIR) filters. Ground waveforms distorted by turbulence were selected to represent mean and mean±standard deviation levels for six metrics, and corresponding FIR filters were generated through a matrix deconvolution process. In order to evaluate how well the FIR filters perform, additional KZKFourier verification cases were devised with different input conditions, and results used as a benchmark. Convolution of shaped boom waveforms modeled using nonturbulent propagation simulations with the new FIR filters showed better agreement on average with KZKFourier statistical results than the N-wave-based FIR filters.
Nonlinear acoustic propagation in low-density media
Authors: Lonzaga Joel B.
Published: April 2023

Nonlinear acoustic propagation in the atmosphere is usually modeled using an augmented Burgers equation accounting for atmospheric absorption and weak nonlinearity. However, the weak-nonlinearity assumption may not apply to acoustic signals propagating from the lower atmosphere that are subsequently refracted downward from the upper atmosphere (e.g., stratosphere and thermosphere) due to the decreasing air density with increasing altitude [Lonzaga, et al., Geophys. J. Int. 200(3), 1347–1361]. Consequently, this paper discusses the effects of a strong nonlinearity that lead to an amplitude-dependent increase in signal propagation speed. This propagation speed is obtained using a perturbation expansion where the leading-order term is simply the small-amplitude sound speed while the first-order term is the existing expression that gives rise to waveform steepening and stretching. Furthermore, the second-order term is proportional to the spectral density of the acoustic signal and is inversely proportional to the local density of the medium. Consequently, for an impulsive signal such as a sonic boom or an infrasound, the second-order effect causes a dispersion of the signal similar to the observed dispersion of acoustic signals from supersonic Concorde as well as from large explosions. This paper also discusses the extension of these results in general low-density propagation media.
Wind profiles measurements and predictions for atmospheric acoustic propagation modeling
Authors: Vecchiotti Andrea , Turo Diego , Vignola Joseph , Foeller Jeff , Ryan Teresa J.
Published: April 2023

This work presents a comprehensive experimental system to measure meteorological conditions with both anemometers and a three-dimensional scanning Doppler LIDAR wind profiler. The LIDAR system captures real-time wind speed gradients at many locations along a particular heading. This work describes a method for extracting a cartesian grid of wind speeds gradients from a range height indicator (RHI) scan pattern. The LIDAR derived wind profiles are compared to logarithmic wind profiles based on single point traditional anemometer measurements. Differences in wind speed profiles observed using the two methods are presented and the implications on long range acoustic propagation modeling are discussed.
Modeling sea state induced atmospheric sound transmission loss
Authors: Vecchiotti Andrea , Ryan Teresa J. , Vignola Joseph , Turo Diego
Published: April 2023

This work presents a numerical study on atmospheric sound propagation over rough rigid surfaces. The intent is to simulate acoustic propagation over water. Methods to estimate sea state induced atmospheric sound transmission loss and relative uncertainties are evaluated. In previous studies, a flat surface with an equivalent impedance was used to account for the effect of surface roughness on sound transmission loss. Equivalent impedances were estimated based on time-domain numerical simulations of atmospheric sound propagation above pseudorandom sea surfaces coherent with a Pierson-Moskowitz spectra. Estimation of equivalent impedances using time- and frequency- domain approaches are compared for cases up to sea state 4. Acoustic excess attenuation due to propagation over a rough surface was predicted by the authors, in a previous work, by correcting the excess attenuation of a propagation over a flat, perfectly reflecting surface. The correction factor was frequency and sea state dependent and included an additional term to account for the uncertainties characteristic of different sea states. Excess attenuation predictions estimated using the equivalent impedance approach are compared with those obtained from the authors’ previous study. Implications of the use of these methods for source detectability determinations are discussed.
Air temperature profiling over different littoral surfaces
Authors: Stengrim Matthew , Obando Nicole , Blackburn Hannah , Vecchiotti Andrea , Turo Diego , Vignola Joseph , Foeller Jeff , Ryan Teresa J.
Published: April 2023

There are many factors that must be considered in the study of atmospheric sound propagation over long distances; these include surface characteristics as well as wind speed and air temperature profiles. This work presents measurements of air temperature profiles over various surfaces. Building a catalogue of this type can enable more realistic case assumptions to be made in an atmospheric acoustic transmission loss model. Accurate air temperature profiles are critical because of the potentially significant impact on the transmission loss predictions. Air temperature profile measurements have been collected by solar radiation shielded temperature loggers mounted 1 m apart on a 7 m mast. Long duration measurements were taken to capture the variability in day and nighttime temperature differentials present over surfaces such as: gravel, vegetated shoreline, marsh grass, lawn grass, water, and asphalt. In particular, measurements performed off shore were done by placing the sensor array on the deck of a pontoon boat. The initial results revealed that this configuration captures a very low elevation warming due to re-radiation from the deck of a boat instead of the true over water temperature. This study highlights the influence of wind speed on the development of the near surface temperature inversions.
Perception of global properties, objects, and settings in natural auditory scenes
Authors: McMullin Margaret A. , Higgins Nathan C. , Gygi Brian , Kumar Rohit , Elhilali Mounya , Snyder Joel S.
Published: April 2023

Theories of auditory scene analysis suggest our perception of scenes relies on identifying and segregating objects within it. However, a more global process may occur while analyzing scenes, which has been evidenced in the visual domain. In our first experiment, we studied perception of eight global properties (e.g., openness), using a collection of 200 high-quality auditory scenes. Participants showed high agreement on their ratings of global properties. The global properties were explained by a two-factor model. Acoustic features of scenes were explained by a seven-factor model, and linearly predicted the global ratings by different amounts (R-squared = 0.33–0.87), although we also observed nonlinear relationships between acoustical and global variables. A multi-layer neural network trained to recognize auditory objects in everyday soundscapes from YouTube shows high-level embeddings of our 200 scenes are correlated with some global variables at earlier stages of processing than others. In a second experiment, we evaluated participants’ accuracy in identifying the setting of and objects within scenes across three durations (1, 2, and 4 s). Overall, participants performed better on the object identification task, but needed longer duration stimuli to do so. These results suggest object identification may require more processing time and/or attention switching than setting identification.
Effects of face masks on novel word learning in preschool children
Authors: Grieco-Calub Tina M. , Gordon Katherine R. , Lalonde Kaylah , Cortez Diana M. , Lowry Stephanie L. , Dwyer Grace A.
Published: April 2023

Face masks worn by talkers compromise the speech signal children use to learn language. There is debate, however, about which type of face mask will be more supportive of language learning in young children. Although clear masks provide more visual access to the talker’s face than surgical masks, they distort the speech signal more than surgical masks. Our goal is to better understand the effects of different face masks on word learning in preschool-age and kindergarten-age children. To achieve this goal, we are comparing children’s ability to learn novel words in conditions that vary on the spectral fidelity of speech and visual access to the talker’s face to simulate the effects of different mask types. Children’s performance is quantified by the number of words learned and the phonological precision of words learned. To date, twelve children have completed the protocol, and the study is ongoing. We will compare children’s word-learning across conditions and evaluate the influence of individual factors such as visual speech reading skills, verbal working memory, and vocabulary knowledge on children’s performance in the various conditions. These findings will have implications for supporting word learning in young children in educational and childcare settings when masks are used.
Single-trial decoding of stimulus pitch from EEG-FFR
Authors: Ho Letitia , Veillette John , Nusbaum Howard
Published: April 2023

The frequency-following response (FFR) is a phase-locked evoked response recorded at the scalp that directly mirrors the frequency content of acoustic stimuli. While once believed to be primarily of subcortical origin, MEG and EEG research has more recently shown that the FFR originates from multiple subcortical and cortical neural sources (Coffey et al., 2016; Hartmann and Weisz, 2019; Tichko and Skoe, 2017). The present study tests whether the frequency of the stimulus can be reliably decoded from frequency-specific power of single-trial high-density EEG, despite the extremely small amplitude of the FFR relative to the background EEG. Since the amplitude of the FFR contributions from the multiple constituent cortical and subcortical sources can be modulated independently, it is reasonable to posit that the scalp distribution of the FFR may be malleable to psychological processes such as selective attention. Past studies on the attentional modulation of the FFR have been inconclusive (e.g., Forte et al., 2017; Hoormann etal., 2004). We therefore also examine the accuracy of the single- trial FFR-based decoding as a function of different attention manipulations.
Voice cue perception and voice gender categorisation via a humanoid robot interface
Authors: Rachman Laura , Meyer Luke , Araiza-Illan Gloria , Gaudrain Etienne , Baskent Deniz
Published: April 2023

Two voice cues, fundamental frequency (F0) and vocal-tract length (VTL), are important for characterising voice gender. Due to their often repetitive nature, psychophysical tests evaluating perception of these vocal cues can at times cause individuals to lose engagement during the test. To help with this, we propose the use of an interactive humanoid NAO robot as an alternative to the conventionally used laptop interface. As a first step, we compare the performance of two psychophysical tests between the robot and laptop interfaces. Experiment I measured F0 and VTL cue perception through an adaptive test in just noticeable differences (JNDs). Experiment II measured voice gender categorisation using F0 and VTL manipulated stimuli. The robot implementation made use of the tactile sensors on the hands and head of the robot for response logging. Performance accuracy between the computer and robot interfaces was functionally similar, confirming data reliability. Test duration comparison showed that both experiments were longer on the NAO robot than the laptop. Despite potential design limitations of the robot interface, both interfaces showed that the F0 and VTL JNDs are very small in normal-hearing listeners, and that normal-hearing listeners make effective use of F0 and VTL cues for voice gender categorisation.
On the influence of the middle ear on the sound pressure level generated in open and occluded earcanals under a bone-conducted stimulation
Authors: Carillo Kévin , Sgard Franck , Ramadier Guillaume , Doutres Olivier
Published: April 2023

The occlusion effect is an acoustic discomfort commonly encountered by earplugs’ users, which corresponds to the increased auditory perception of the bone-conducted sound mainly at low frequencies. This perception is accompanied by the augmentation of the sound pressure level in the earcanal when occluded by the earplug compared to the open case. While the source of the SPL generated in the earcanal in both open and occluded cases is mainly attributed to the vibration of the earcanal wall, the sound radiation of the tympanic membrane that stems from the middle ear vibration is commonly considered as not significant. To investigate this phenomenon, a finite element model that incorporates the middle ear components into a realistic human outer ear is developed. First, the finite element model is evaluated by comparing the acoustic impedance computed at the eardrum surface to literature data obtained on human subjects. Second, the finite element model is used to quantify the contribution of the sound radiation that originates from the middle ear on the sound pressure level generated in both open and occluded earcanals under a bone-conducted stimulation.
Evaluating compliance on a gamified auditory training task in Veterans
Authors: Mendiola Jessica G. , Lelo de Larrea-Mancera E. S. , Gallun Frederick J. , Seitz Aaron , Diedesch Anna C.
Published: April 2023

Service members and Veterans are regularly exposed to environmental factors that have been shown to contribute to hearing deficits. These listening deficits may present as auditory processing complaints such as difficulty listening in background noise in the absence of a peripheral hearing loss. The public app, Listen: An Auditory Training Experience, developed by University of California Riverside Brain Game Center, aims to improve overall speech comprehension by targeting skills related to spectro-temporal modulations, spatialized sound cues, and auditory memory tasks. Ten Veterans participated in a two-week gamified auditory training program. Compliance on the auditory training tasks was assessed by monitoring the number of trials accomplished each day, accuracy above chance, reaction time, and improvements in performance over time. Improvements were also monitored for untrained auditory tasks, such as speech-in-noise performance and a battery of central auditory processing assessments.
Long-latency component of stimulus frequency otoacoustic emissions: Relationship to behavioral measures
Authors: Akhtar Uzma S. , Moleti Arturo , Sisto Renata , Dhar Sumitrajit
Published: April 2023

Uncertainties regarding the generation mechanism and source of human stimulus frequency otoacoustic emissions (SFOAEs), as well as the possible generation of artifacts, have previously restricted the use of SFOAEs in clinical settings for assessing cochlear function. Over the years, advanced time-frequency analysis of SFOAEs, using models of SFOAE delays as a function of frequency, have been implemented in an effort to isolate the long-latency (LL) component of SFOAEs—improving the signal-to-noise ratio and the artifact rejection as noteworthy byproducts. In order to test the hypothesis that behavioral measures and SFOAE LL component both reflect the activity of limited cochlear regions, the relationship between SFOAE LL component and behavioral measures was investigated. SFOAEs, behavioral thresholds and psychophysical tuning curves (PTCs) were measured for probe frequencies centered around 0.75, 1, 2, 4, 8, 10, 12.5 and 14 kHz. Stimulus levels for PTCs (10 dB SL) and SFOAEs (10, 20 and 30 dB SL) were referenced to behavioral thresholds at each frequency. Using the same in situ calibration technique using Thevenin-equivalent source parameters, behavioral thresholds and SFOAE-estimated thresholds from input-output functions of the SFOAE LL component were strongly correlated. Furthermore, there was a strong correlation between SFOAE-based and psychophysical tuning estimates.
Portable automated rapid testing: Validation of automated testing on listeners from India
Authors: Prabhu Prashanth , Pattundan Vardha , Priya Sonal , Das Dibyendu , Patro Chhayakanta , Srinivasan Nirmal Kumar , Gallun Frederick J.
Published: April 2023

Portable Automated Rapid Testing (PART) is an iPad application (https://braingamecenter.ucr.edu/games/p-a-r-t/) capable of measuring various psychoacoustic thresholds (speech on speech masking, temporal, spectral, and spectrotemporal modulation detection, temporal gap detection, frequency modulation tasks, and pure tone detection in noise) in an automated and rapid format using commercially available headphones. The app has been validated previously in native speakers of English and an adapted version of the app has been validated in young normal hearing listeners from Mexico. Here, we present psychoacoustic threshold data for a large cohort of younger college going listeners from India whose native language is not English but are proficient in English. The thresholds obtained from this group will be compared against previously published thresholds based on native speakers of English. It is hypothesized that there will not be any significant differences in thresholds between listeners from India and the thresholds published in the literature. These results will give us the required evidence to start using this freely available app to measure reliable thresholds of various central auditory processing measures in non-native speakers of English who are proficient in the language as well.
Vibratory responses to outer hair cell-generated distortion products along the width of the mouse organ of Corti
Authors: Dewey James
Published: April 2023

Mammalian hearing sensitivity depends on the amplification of cochlear vibrations by outer hair cells (OHCs). OHCs are thought to generate amplifying forces through electromotility, i.e., voltage-driven changes in cell length, though how exactly these forces influence the motion of the surrounding organ of Corti structures remains incompletely understood. Here, in the mouse cochlear apex, optical coherence tomography was used to characterize electromotility-induced vibrations along the axis of the OHCs and along the widths of both the basilar membrane (BM) and reticular lamina (RL). Two-tone stimuli were used to elicit OHC-driven vibrations at a variety of intermodulation distortion-product (DP) frequencies. For a wide range of DP frequencies, out-of-phase motions were observed between the bottoms and tops of the OHCs, as well as between the tops of the OHCs and the lateral supporting cells. However, along the BM, phase variations were only observed at frequencies above the characteristic frequency (CF), with in-phase motions being observed at lower frequencies. The data indicate that OHCs can rapidly deform the top of the organ of Corti, while the BM response is more complex, likely being dominated by traveling-wave energy at and below the CF. [Work supported by NIH/NIDCD R21 DC019209 and the Hearing Health Foundation.]
Group conversation assessment in realistic acoustic scenes
Authors: Klockgether Stefan , Cattaneo Manuel , Weiss Robin , Derleth R. Peter
Published: April 2023

Successful communication in background noise is a continuous interaction between conversation partners. They continuously exchange conscious, unconscious, verbal, and non-verbal information regarding how well the other person is understood. Human communication is not limited to one-on-one interactions but can also happen in group conversation situations. The complexity of taking an active part in a group conversation is much higher though, since the continuous interaction happens with more than one conversation partner at the same time. To investigate human communication behavior, real conversations between groups of six people were observed in the Sonova Real Life Lab. All participants were allowed to move around freely within the lab space. The head position and orientation of all six participants was continuously monitored with an optical motion capturing system. The voices of all participants were recorded with wireless headset microphones, which allowed to assess individual vocal effort. During the conversation situation, background noise was played from all four directions simultaneously and systematically varied in overall level. The individual position data and vocal effort were used to estimate perceived communication difficulty and signal to noise ratios. The head orientation data was analyzed to estimate which individuals the participants were talking and listening to.
Rate dependence in outer hair cell mediated active processes: Determining Prestin’s Speed Limit
Authors: Grosh Karl , Cai Wen
Published: April 2023

The electromotility of the outer hair cell (OHC) contributes to the sensitivity of the mammalian cochlea by amplifying traveling waves through electrical-to-mechanical energy conversion realized at the molecular level by an electromotile protein called prestin. Rate-dependent effects, including viscous damping, transmembrane electrical impedance, and state-dependent conformal transitions, hold the potential to attenuate OHC-mediated active processes at high frequencies thereby rendering prestin ineffective in high frequency cycle-by-cycle amplification. Determining the upper frequency limit of prestin remains a central challenge in cochlear biophysics. In this study, we will build a simplified OHC model to explore the influence of the rate dependence on active force generation and power deposition. Through numerical investigations, the proposed model can be used to model charge and electromotility data from in vitro experiments, but subtle variations in the rate parameters significantly change the predictions of electromechanical force as well as the power deposition. Based on these theoretical considerations, we propose an experimental approach to consistently determine the rate dependence and other OHC response parameters by characterizing the electrical and mechanical behavior about a resting position. This approach holds the potential to conclusively determine the upper frequency limit of prestin under physiological resting conditions.
A molecular psychophysical approach to identify cues for tone-in-noise detection in simultaneous masking
Authors: Jennings Skyler G. , Schwarz Douglas M. , Carney Laurel H. , Henry Kenneth S.
Published: April 2023

Experiments involving the detection of a tone presented in noise form the basis of many models of psychophysics that are used to estimate frequency resolution and cochlear compression for listeners with normal and impaired hearing. Despite the wide-spread application of tone-in-noise experiments, the cues used by listeners to detect the tone are a matter of debate. Here we adopt a molecular psychophysics approach – decision variable correlation (DVC) – to evaluate the extent to which trial-by-trial responses are consistent with candidate decision variables, including stimulus energy or the temporal envelope. We measured detection thresholds in normal-hearing adults for a 1000-Hz tone presented in one-third octave noise centered on the tone frequency. The tone and noise were gated simultaneously and thresholds were measured for durations of 10, 20, 50, and 100ms. We limited the reliability of energy-based cues by incorporating a roving-level paradigm. Similarly, the use of short tones (e.g., 10 ms) limited the reliability of envelope-based cues. Our results reveal that listeners adopted a strategy that emphasized energy-based cues for short-duration tones and envelope-based cues for long-duration tones. This finding suggests that models of human psychophysics may benefit from incorporating a decision device that adjusts cue weights based on stimulus duration.
Is the rapid decline in interaural time difference sensitivity above 700 Hz explained by downward spread of excitation into the frequency dominant region?
Authors: Goupell Matthew J. , Stecker G. Christopher , Tollin Daniel J.
Published: April 2023

Low-frequency temporal-fine-structure interaural time differences (ITDs) are so important that they almost completely dominate localization of broadband sounds. This “Dominant Region” occurs at ∼700 Hz and also coincides with best ITD discrimination sensitivity. Above this frequency range, ITD sensitivity worsens, until ∼1400 Hz where it rapidly becomes impossible. Explaining how listeners’ ITD sensitivity transitions from best sensitivity to impossible to detect within ∼1 octave challenges models of ITD processing. One possible explanation is that listeners continue to use binaural information from the Dominant Region even for higher-frequency pure tones. Within this explanation, the steep decline in ITD sensitivity reflects the high-frequency limb of peripheral frequency tuning for neurons within the Dominant Region (i.e., downward spread of excitation). To test this hypothesis, we measured the upper frequency limit of ITD processing as a function of stimulus level. Normal-hearing listeners were tested on a left-right ITD discrimination task. Stimuli were pure tones with 500–1500Hz frequencies and 10–50 dB sensation levels. It was hypothesized that the upper frequency limit of ITD processing would decrease in frequency with decreasing level, which would indicate that the downward spread of excitation into the Dominant Region at least partially explains the rapid decline in ITD sensitivity.
A physiological study of forward masking: Recovery of discharge rate to probe tones in inferior colliculus
Authors: Agarwalla Swapna , Carney Laurel H.
Published: April 2023

In forward masking the perception of a target sound (probe) is degraded due to the presence of a preceding sound (masker). Two factors contributing to the probe response are (i) the temporal separation (delay) between the masker and probe and (ii) the interstimulus interval (ISI). Human listeners recover from forward masking to quiet probe thresholds for delays of 150–300 ms [Jesteadt et al., JASA 71, 950 (1982)]. Similarly, physiological studies have reported neural correlates of behavioral forward masking at the level of the inferior colliculus (IC), with 300-ms recovery of neural thresholds to the probe [Nelson et al., J. Neurosci. 29, 2553 (2019)]. Here, we estimated recovery of the discharge rate of IC neurons after forward maskers. We also quantified the impact of previous masker trials on IC rates by varying ISI. We recorded from the IC of awake rabbits using gaussian noise forward maskers and pure-tone probes. Interestingly, we observed significant effects of prior masking trials on discharge rates in response to the probe, even for ISIs larger than those typically used in psychophysical experiments. Our results show that ISIs of at least 1.5 s were required for full recovery of discharge rates after 70 dB SPL gaussian noise maskers. [NIH-NIDCD-010813.]
Speech recognition in the presence of speech maskers in children
Authors: Balan Jithin R. , Fu Qian-Jie , Galvin John J. , Mishra Srikanta K.
Published: April 2023

Listening to a target talker in the presence of other talkers follows a protracted developmental period. Such listening skills are critical for speech-language development and have clinical value. The purpose of the present study was to examine speech-in-speech recognition ability using digits in children. The major advantages of using digits are that it overcomes the biggest challenge of test administration, and digits are among the few first words children learn. Data were collected from 32 normal-hearing children (4–12 years) using full bandwidth speech materials. The test had four conditions like the Listening in Spatial Noise test. (1) Low cue: The target (male talker) and two male maskers were presented from the front. (2) Talker advantage: The target and two female maskers were presented from the front. (3) Spatial advantage: The target was presented from the front, and two male maskers were presented, one each from ±90°. (4) The target was presented from the front, and two female maskers were presented, one from ±90°. Results demonstrate developmental effects, good test-retest reliability, and feasibility of the computerized version of the test. Furthermore, results will be discussed in the context of various conditions and potential clinical applications.
The effects of preceding sound on three measures related to gain reduction
Authors: Strickland Elizabeth A. , McNeill Madison , Park Heesun
Published: April 2023

The medial olivocochlear reflex (MOCR) decreases the gain of the cochlear active process in response to sound. We have used psychoacoustic techniques to show behavioral effects of gain reduction, which could be consistent with the MOCR. We have used forward masking paradigms understood to measure frequency selectivity and the input/output function at the level of the cochlea using stimuli (masker and signal) that should be too short to evoke the MOCR. A precursor sound is then presented before these stimuli to evoke the MOCR. In previous studies, we have shown that a precursor: (1) increases signal threshold more after an off-frequency masker than the on-frequency one for forward maskers matched in effectiveness to increase signal threshold to 5 dB SL, (2) may increase on-frequency masker threshold required to mask a signal of 15-20 dB SL, and (3) may decrease suppression in forward masking. All of these effects would be consistent with a reduction in gain by the precursor, possibly by the MOCR. In the current study, these effects are all measured within the same listeners, using a more effective precursor than has been used in previous studies. The relationship between the measures will be discussed.