bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of acoustic metasurfaces for reduction of broadband noise generated by tire-pavement interaction
Authors: Heo Hyeonu , Ju Jaehyung , Neogi Arup , Krokhin Arkadii
Published: May 2022

Noise pollution by traffic is the most widespread environmental problems that cause sleep disturbance, hearing damage, even cardiovascular disease. The primary noise sources of the vehicle are the engine, exhaust, aeroacoustics, and tire-pavement interaction. Among them, a dominant noise within automobiles occurs from the tire-pavement interaction. Most noise suppression efforts aim to use sound absorbers or cavity resonators to narrow the bandwidth of acoustic frequencies using acoustic foams or Helmholtz resonators. However, the effectiveness of existing methods of noise reduction is limited by the design constraints and material itself. In this study, we propose artificially designed reflecting acoustic metasurfaces to control and isolate sound generated by a moving car. The proposed design can significantly reduce the noise arising from tire-pavement interaction over a broadband of acoustic frequencies under 2 kHz and over a wide range of vehicle speeds. A set of experiments with lab-scale and field tests have demonstrated that the lightweight metamaterial displaced inside the tires gives 2—5 dB stronger reduction of 200—300 Hz noise inside the car cabin than currently used acoustic foam. The proposed approach can be extended to other objects generating low-frequency mechanical noise. [Work supported by the National Science Foundation under EFRI Grant No. 1741677.]
Phononic crystal as a homogeneous viscous metamaterial
Authors: Krokhin Arkadii , Ibarias Martin , Zubov Yurii , Arriaga Jesus
Published: May 2022

At low frequencies, a phononic crystal behaves like a homogeneous medium. Different variants of homogenization technique have been recently proposed to calculate the effective elastic parameters of periodic medium. Here, we develop a homogenization theory for a phononic crystal of solid rods in a viscous fluid. Using the plane wave expansion method, we derive analytical formula for the decay coefficient of low frequency sound propagating in a 2D Bravais lattice with arbitrary unit cell. It is shown that due to the formation of a viscous boundary layer around each cylinder, the losses are enhanced by two to four orders of magnitude as compared to the losses in the free fluid. This enhancement depends on the filling fraction of solid rod and it becomes very strong for almost touching scatterers when sound propagates through narrow slits between the neighbouring rods. Also, the decay coefficient in a phononic crystal scales with frequency as ω2, unlike scaling √ω known for free viscous fluid. The enhanced viscous losses are associated with high effective viscosity of phononic crystal. Like other effective parameters the effective viscosity exhibits strong anisotropy, if the unit cell is asymmetric. The proposed theory can be used for evaluation of efficiency of acoustic devices based on phononic crystals. [This study is supported by NSF Grant No. 1741677.]
The evolution and maturation of the electric guitar as a system
Authors: Pastore M. Torben , Deshpande Nikhil
Published: May 2022

The electric guitar came to its initial prominence in the 1940s when its volume allowed jazz guitarists like Charlie Christian to step out in front of the rhythm section like other soloists, competing with the brass, wind, and piano. Further changes in the playing and design of the instrument came with exploitation of the interaction of the electric guitar, tube amplifiers, and analog effects as a larger system. Especially in the rock and funk idioms, the playing and construction of the overall instrument evolved and expanded rapidly with the mainstream embrace of digital technology. This talk will consider the evolution of the electric guitar as a system up through today and consider why it seems the instrument has fully evolved and is unlikely to experience further seismic shifts, especially as the overall thrust of music has shifted to digitally-manipulated sound that is often entirely independent of the physical playing of any instrument.
Characteristics of Lamb waves from 2022 Hunga Tonga volcano eruption detected in the Moscow region
Authors: Kulichkov Sergey , Chunchuzov Igor P. , Popov Oleg , Perepelkin Vitaly
Published: May 2022

We present characteristics (waveform, coherence, phase speed, and propagation directions) of Lamb waves from 2022 Hunga Tonga volcano eruption detected by the network of microbarographs in the Moscow region. The pressure waves were detected both on the day of the volcano eruption (January 15 UTC) and after the time interval during which they circled the entire globe after the first detection and returned to the receiving point (on January 17 UTC). This made it possible to study the change in the waveform and duration of the Lamb wave depending on the distance from the volcanic eruption site and the influence of stratification of wind speed and atmospheric temperature on the signal waveform. [This work was supported by the Russian Science Foundation, Grant No. 21-17-0002.]
Frequencies of atmospheric Schumann resonances correlate with the frequencies of acoustically detected stellar massive particles
Authors: Ostrovskii Igor
Published: May 2022

The Schumann resonances (SR) in Earth’s atmosphere are electromagnetic waves of extremely low frequencies (ELF). The first four modes propagate at 7.4 Hz–26 Hz. Recently, the massive particles emitted by the Sun/stars have been detected by two acoustical methods including the acousto-electric properties of 10 MHz quartz oscillators and ELF vibrations of suspended lightweight crystals. In this work, the frequencies of solar/stellar massive particles propagating through the atmosphere and landing on Earth are revealed and compared with SR frequencies. The measurements of acousto-electric admittance Y of free vibrating quartz oscillators reveal that Y(F) are changed from known resonance-antiresonance curve to a pulse type dependency Yp(F) with a number of deep minima. They occur when piezoelectric crystal axis is oriented toward a star emitting massive particles. The waveforms (WF) of vibrating suspended light-weight quartz crystals were detected by a laser Doppler vibrometer. The Fast Fourier transform spectra obtained from the Yp(F) and WF time dependencies reveal the spectra of massive particles M(F) with which they were hitting the crystals. The M(F) spectra extend from 2 to ∼30 Hz, which correlates with SR spectra. In addition, the maxima in SR modes and M(F) spectra are very close or coincide.
Mars soundscape: Review of the first sounds recorded by the Perseverance microphones
Authors: Chide Baptiste , Lorenz Ralph , Murdoch Naomi , Stott Alexander , Mimoun David , Jacob Xavier , Bertrand Tanguy , Lanza Nina , Maurice Sylvestre , Wiens Roger
Published: May 2022

On February 18, 2021, NASA’s Perseverance rover landed in Jezero Crater carrying the two first microphones operating on the surface of Mars: the SuperCam microphone, positioned on top of the rotating rover’s mast and the EDL microphone fixed on the body of the rover. Working flawlessly since then, they provide the first characterization of Mars’ acoustic environment in the audible range and beyond, from 20 Hz to 50 kHz. Recorded sounds originate from three main sources: the atmosphere (turbulence, wind), the shock-waves generated by the Supercam pulsed laser ablating rocks, and hardware-induced artificial sounds such as the signal generated by the high-speed rotating blades of the Ingenuity helicopter. After one year, the Perseverance playlist features more than 5 hours of martian sounds. In addition to providing an unprecedented short timescale characterization of the wind, temperature fluctuations, and the turbulence dissipative regime, this dataset highlights the unique sound propagation properties of the low-pressure CO2-dominated Mars atmosphere: acoustic impedance varying with the season, large intrinsic attenuation of the high frequencies, and the dispersion of the sound speed in the audible range. This presentation will review these results to date.
Assessing bottom-up and top-down effects on speech-in-noise recognition by adolescents with normal hearing or cochlear implants
Authors: Nittrouer Susan , Lowenstein Joanna , Sinex Donal
Published: May 2022

The terms “bottom-up” and “top-down” effects are commonly used when measuring speech recognition in competing sounds to refer to listeners’ abilities to exploit details of the sensory input and to use linguistic constraints, respectively. The magnitude of each effect has been assessed for listeners with cochlear implants, but typically in separate studies. We varied the availability of bottom-up and top-down information in a single experiment by generating sentences with three kinds of clause structure, from less to more restrictive, in three different babbled backgrounds, with sex and number of talkers varied. Next we examined the factors that might explain abilities to use bottom-up and top-down information in speech-in-noise recognition. Predictor variables included spectral modulation detection abilities, lexical-syntactic knowledge, verbal working memory, and phonological sensitivity. Participants were 14-year-olds with normal hearing (NH; 46) or with cochlear implants (CIs; 46). Adolescents with cochlear implants showed deficits in their abilities both to segregate the target speech from background babble and to benefit from restrictive syntactic constructions. For adolescents with NH, only verbal working memory explained variability in abilities to use bottom-up or top-down information in speech-in-noise recognition. For adolescents with CIs, only spectral modulation detection abilities explained their abilities to apply these effects.
Spoken word recognition by bilingual and monolingual children
Authors: Levi Susannah V. , Karthikeyan Nandita
Published: May 2022

Previous research has demonstrated a bilingual advantage in the domains of executive function and social processing, including a type of social processing tied to speech perception—listening to differences between speakers’ voices. Despite numerous studies showing an advantage, the existence of such an advantage has also been widely challenged. In the current study, we test whether monolingual and bilingual children differ in spoken word recognition for speech produced by foreign-accented speakers, as it may be the case that bilingual children have more experience with foreign-accented speech. Children completed a spoken word recognition task in which they heard high and low familiarity words (e.g., “hair” vs “loom”) mixed with noise. Logistic mixed-effects models revealed the expected effects of word familiarity (high > low) and of age (older > younger). No effect of bilingual status or of language ability were found. Although the findings do not demonstrate a benefit of bilingualism, we argue that it is important to report these findings given the controversy surrounding other bilingual advantage studies. [Work supported by NIDCD 1R03DC009851.]
Super-resolution, time-reversal focusing using path-diverting scatterers
Authors: Golightly Emily D. , Kingsley Adam D. , Higgins Rebekah , Anderson Brian E.
Published: May 2022

This presentation will discuss the possibility of using path-diverting scatterers in time reversal focusing to achieve super resolution. In particular, use of a one-dimensional pipe system with varying lengths of diverting pipes is shown to decrease the effective wave speed. This provides insight, albeit in an extreme case, of how scatterers can force sound to travel a longer path as the waves converge to the focal location. As the effective wave speed decreases, the spatial extent of the focusing decreases, creating an apparent super resolution when compared to the speed of sound in an unaltered pipe system. Previous work achieved super resolution with what they described as scatterers, but it is likely that their scatterers are better classified as resonators, and consequently, it has yet to be shown that scatterers can be used to obtain super resolution.
An n-order hold approach for fractional-delay interpolation in auralization
Authors: Christian Andrew , Ali Randall , Greenwood Eric
Published: May 2022

During the signal processing chain of an auralization simulating the propagation of a sound from a moving source to a stationary receiver, it is often necessary to interpolate between the samples of the source signal in order to arrive at uniformly-spaced samples at the receiver. In some cases, this interpolation is done in the receiver time frame—where the “input” samples of the source have become irregularly spaced due to time dilation effects. Canonical band-limited interpolation methods (i.e., sinc and sinc-derived approaches) cannot be applied in this case as they rely on having a uniformly-spaced input. The use of geometric interpolation methods that can handle irregularly-spaced input may not be grounded in signal processing principles and may produce unwanted artifacts and noise. This presentation outlines the possibility of embedding an irregularly spaced n-order hold signal within a highly over-sampled uniformly-spaced signal and then processing down to the desired sampling rate through successive decimations. Initial distortion and noise characteristics of the approach are shown for some basic propagation geometries. The possible benefits of using such an approach in an auralization scheme with a time-varying Doppler shift are discussed including: the prevention of aliasing, processing time advantages, and real-time processing.
Normal mode acoustic modeling using measurements of ocean sound speed from the Beaufort Sea
Authors: Desrochers Jessica , Van Uffelen Lora , Webster Sarah E. , Muniz Alexander P. , Graupe Cristian E. , Pomales Velázquez Luis O.
Published: May 2022

Over the last few decades, environmental changes in the Arctic have resulted in a subsurface acoustic duct located between 100- and 300-m depth, known as the Beaufort Duct. This subsurface duct allows for long-range acoustic transmission with little to no interaction with the sea surface or seafloor. In a 2017 long-range acoustic tomography experiment, two Seagliders traversed between five active sources moored within the duct which transmitted linear frequency modulated (LFM) sweeps centered around 250 Hz. These Seagliders were equipped with conductivity, temperature, depth (CTD) sensors as well as passive acoustic receivers. The environmental measurements were used to create sound speed profiles for input into broadband parabolic equation and normal mode acoustic propagation models. The normal mode models provide physical insight into the relationship between the peak arrival and the final cutoff of the ducted acoustic receptions. Modal group speeds from the predictions are used to interpret the acoustic arrival patterns measured on the Seagliders.
Midfrequency sound transmission from mobile sources in a deep Arctic ocean at short and medium ranges: Time-domain modeling and data analysis
Authors: Ivakin Anatoliy N. , Joseph John E. , Reeder D. Benjamin
Published: May 2022

Midfrequency (2300–3000 Hz) LFM sweeps (3 s-long, one per minute) and CW 57 s-long signals at multiple frequencies (950, 1050, 1150, 2800, 2900, and 3000 Hz) were transmitted by two mobile sources EMATTs moving at three knots in circular patterns under ice in the Beaufort Sea on March 12, 2016. Acoustic pressure time series were recorded on five vertically and horizontally separated receivers Acousonde, which provided different combinations of source-receiver ranges (0.3–10 km) and depths (45–183 m). A time-domain model of propagation and reverberation is suggested that accounts for refraction in water column and scattering from ocean boundaries (bottom and ice). Effects of spatial variations of the environment, particularly the two shallow ducts, at 0–75 m and 75–250 m water depths, as well as bottom and ice roughness, are demonstrated. Preliminary results of the model-data comparisons are presented. Possibilities for remote sensing of the arctic environment are discussed. [Work supported by ONR.]
Towards developing a generalized semi-coherent three-dimensional energy flux model
Authors: Langhirt Mark A. , Holland Charles W. , Lin Ying-Tsong , Martinelli Sheri , Brown Daniel C.
Published: May 2022

The energy flux method can be interpreted as an integration over propagation angle of a semi-classical (WKB) modal continuum, which yields an averaged incoherent intensity field with depth-dependent intensity bands that decay in range. Range dependence is typically incorporated via the adiabatic modes approximation and use of the ray invariant to map propagation angles. Though the energy flux method averages out nearly all of the field structure, it has the primary advantages of avoiding finding eigenvalues and eigenrays and its computational effort does not directly scale with frequency or range. The method has also been extended in the past decade to include a convergence factor derived from the interference of neighboring modes, producing a semi-coherent solution that captures some convergence structure analogous to high-frequency caustics. Since the development of the semi-coherent energy flux method, it has so far only been applied to Nx2D environmental models, but should theoretically be applicable in a 3D environment without the assumption of azimuthal symmetry or the exclusion of horizontal refraction. This paper will discuss the theoretical derivation and numerical implementation of a generalized semi-coherent three-dimensional energy flux model. [This study is funded by the NDSEG Fellowship program.]
Breast cancer tissue stiffness assessment using transfer learning ultrasound elastography: A phantom study
Authors: An Justin , Abdus-Shakur Tasneem , Denis Max
Published: May 2022

In this work, a phantom study is performed to investigate the feasibility of tissue stiffness assessment of breast cancer masses using transfer learning ultrasound elastography. A transfer learning ultrasound elastography model is developed to classify the breast masses into quantifiable Young’s modulus (kilopascals, kP) values regimes. The transfer learning model combines features of ultrasound elastography elastograms and images from Google’s deep learning models. The elastogram features used in the training and validation of the transfer learning model were obtained from a calibrated elastography phantom with inclusions having various Young’s moduli. The model was tested on a breast phantom with spherical inclusions. Test results show that the transfer learning model yields greater than 88% validation accuracy. Further results and limitations of the transfer learning techniques will be presented and discussed.
Comparison between focused ultrasound and dry needling treatments in a murine Achilles tendinopathy model
Authors: Smallcomb Molly , Khandare Sujata , Elliott Jacob C. , Vidt Meghan E. , Simon Julianna C.
Published: May 2022

Tendinopathy remains a common and debilitating condition that shows mixed success rates in response to treatment. Focused ultrasound (fUS) histotripsy is a non-invasive therapy that can mechanically fractionate soft tissues through bubble creation, oscillation, and collapse. Although collagenous tissues show resistance to full mechanical fractionation, previous studies in ex vivo murine tendons found acoustic parameters that create microdamage while preserving mechanical properties. Our objective is to compare dry needling (DN) or fUS treatments in a murine tendinopathy model. Achilles tenotomy was performed in 26 rats. One week later, tendons were treated with DN (30G needle, five fenestrations over 20 s) or fUS (1.5MHz, 1-ms pulses at 10 Hz for 60 s, p+ = 89 MPa, p− = 26 MPa). Blood was collected from the tail vein immediately before and after treatment and 1-week post-intervention. Tendons were harvested for histology or mechanical testing. Results show no differences between fUS and DN in the release of IGF-I and TGF-β healing factors. No differences were found between interventions and controls in H&E-stained histology. Stiffness and percent relaxation of DN-treated tendons were lower than controls (p = 0.0041, p = 0.0441, respectively), whereas fUS-treated properties were similar. Fromthese results, fUS treatment may be a viable alternative to DN in the treatment of tendinopathy. [Funding: NSF-GRFP-DGE1255832 and NIH-NIBIB-EB027886]
Managing occupational noise from blasts
Authors: Manuel Gethin , Waddington David
Published: May 2022

The aim of this work is to examine the current best practice for the assessment of auditory hazards associated with occupational impulsive noise for a UK-based test site. A summary of the literature is presented on the measurement methodologies, hearing conservation, and relevant guidance for the selection of hearing protection within the context of near-field impulsive noise. The current U,K. best practice recommends the adapted HML method from Defence Standard 0027:2015 using a C-peak measurement of exposure to compare with the national regulations. On-site measurements were made at the DNV Spadeadam Testing and Research Site (STaR), which performs full-scale high-intensity blast testing. Analyses of the trials data show that the C-peak personnel exposures resulted in acceptable levels below the 140dBCpk limit within the national regulations when using the prescribed hearing protection, according to the adapted HML method. It is concluded that the adapted HML assessment is unclear on how excessive low-frequency content and multiple pressure peaks are accounted for. The implication of this work is that further research is required to improve current best practice to quantify the uncertainties introduced by the additional characteristics found within real impulsive noise exposures.
Occluded insertion loss from intracochlear pressure measurements during acoustic shock wave exposure
Authors: Greene Nathaniel , Anderson David A. , Argo Theodore F.
Published: May 2022

Auditory injuries are a common result of high intensity noise exposure, and hearing protective devices (HPDs) can mitigate this injury. Current evaluation methods use manikins to measure ear canal SPLs, but neglect alternate sound conduction pathways. We have previously reported intracochlear pressures in cadaveric human specimens to high-level impulse noise, revealing a substantial bone conducted component. Here, we estimate insertion loss during HPD use from intracochlear pressures in those same specimens. Cadaveric specimens were exposed to shock waves with peak overpressures of 7–83 kPa. Fiber optic pressure sensors were placed in the external, middle, and inner ears and responses measured with ears unoccluded and with four HPDs. Spectral insertion loss was calculated for each exposure level in the frequency domain. Insertion losses calculated from EAC pressures were comparable across levels, consistent with results from acoustic manikins. In contrast, insertion loss calculated from intracochlear pressures were generally lower in magnitude, but increased with the exposure level, likely due to substantial contributions of secondary transmission pathways. Unfortunately, variability in intracochlear pressures limit insertion loss estimate utility. As a proof of concept, we show that averaging multiple exposures increased signal-to-noise considerably, similar noise reduction strategies should be utilized in future studies.
Methods for validation of electromechanical evaluation of hearing protection
Authors: Argo Theodore F. , Brown Andrew D. , Audet David J. , Greene Nathaniel , McCallick Caylin R. , Sammeth Carol A. , Anderson David A. , Rule Gregory T.
Published: May 2022

Preventing hearing injury while maintaining situational awareness is of critical importance while using hearing protection devices (HPDs). Determining the optimal HPD for such varied conditions as operating machinery, riding in aircraft, and using firearms is a non-trivial task. Currently, the Noise Reduction Rating (NRR) is the only required HPD specification; other important characteristics of advanced HPDs are not reported in a standardized manner despite the availability of relevant test standards. Barriers to standardized performance reporting are the use of human subjects and the range of performance capabilities of commercially available HPDs. To complement existing test standards and support standardization of performance reporting across a broader range of performance capabilities, a suite of quantitative, sensor-based tests is being developed to quickly, inexpensively, and comprehensively evaluate candidate HPDs. The five-test battery evaluates signal quality, sound localization, level-dependent frequency response, electronic self-noise, and impulse noise response. In parallel, a set of human subject tests is being developed to validate the electromechanical metrics. Here, we will present (1) preliminary results comparing human performance with complementary electromechanical data and (2) a software tool under development incorporating the electromechanical tests to optimize HPD selection for application-specific hearing protection.
A comparison of methods to measure the sound attenuation of active noise reduction hearing protectors
Authors: Wu Xiaolin , Li Xiaodong , Sang Jinqiu , Cheng Xiaobin
Published: May 2022

Hearing protectors equipped with active noise reduction (ANR) functions have become popular and widespread in recent years. It is important to assess the sound attenuation performance of the ANR hearing protectors properly, which remains a problem. This work studies several typical measurement methods, including the real-ear attenuation at threshold (REAT), microphone in real-ear (MIRE), and the acoustic test fixture (ATF). In order to reduce the masking effect from the noise generated from the ANR electronic system when ANR is turned on during the REAT test, a modified tone sound instead of one-third octave band noise is used as the test signal. The results obtained from the different measurement methods on several ANR headphones and earphones are compared and the differences are discussed. It is found that the measurement differences among those methods are huge. The values of active insertion loss measured by the REAT method are much lower than those assessed by the MIRE procedure. This work contributes to the development of the test methods to assess the sound attenuation of the ANR hearing protectors.
Experimental study of the level-dependent softening of carbon particle stacks
Authors: Song Guochenhao , Bolton J. S.
Published: May 2022

Recently, it has been observed that a particle stack’s elastic modulus and damping change with incident levels. Hence, the measured normal incidence absorption coefficient also varies: i.e., the quarter-wave resonance peak shifts to a lower frequency and grows broader under progressively higher incident sound levels. Therefore, models with strain-dependent modulus and damping have been developed for sand particles based on a series of cyclic triaxial tests, while more recently, a velocity-dependent modulus was proposed to model the acoustically induced elastic softening for the hollow glass beads. To investigate the nature of this nonlinear behavior, the absorption coefficients of a 30 mm carbon particle stack were measured under four types of band-passed input signals (i.e., 500–1000 Hz, 500–2000 Hz, 500–4000 Hz, and 500–8000 Hz), each with 15 levels in steps of 1 dB. The input signals were designed to span the resonance frequency and to extend beyond to various degrees. The integrated sound pressure level, velocity, and displacement at the particle stack surface were calculated and were used to normalize the changing modulus and damping. It was found that only the total rms surface displacement can align the changing properties for all measurements.
Nonlinear acoustic phenomena in high amplitude time reversal focusing of airborne sound in a 1-D system
Authors: Hogg Michael M. , Patchett Brian D. , Clift Jay M. , Anderson Brian E.
Published: May 2022

Time reversal (TR) is a process that can be used to generate high amplitude focusing of sound. It has been previously shown that using TR in reverberant environments to cause high amplitude foci will in fact have multiple nonlinear properties including waveform steepening and a nonlinear increase in peak pressure compressions. This study investigates the removal of one possible cause for these phenomena: free-space Mach stems. By isolating the focus into a 1-D system, the potential formation of Mach stems is eliminated so that remaining effects can be qualitatively observed. To achieve this, a system of pipes is used to restrict the focused waves to be planar in a 1-D reverberant environment. Preliminary results have shown that waveform steepening effects remain as expected but that the nonlinear increase in compression amplitudes disappears, which is consistent with the idea that free-space Mach stems cannot be formed in a 1-D system.
Temporal binding window between three different sensory modalities: Auditory, visual, and tactile
Authors: Oh Yonghee , Borges Kayla , Meyers Kelli , Lopez Altemis , Spratlin Shelbey , Fisch Elizabeth
Published: May 2022

Multisensory integration is crucial to perceptual understanding, but cues from multiple modalities do not necessarily arrive at the brain simultaneously. The window of time in which sensory inputs can be interpreted as simultaneous is termed the “temporal binding window” (TBW). Evidence suggests unimodal temporal discrimination is altered in a series of neurodevelopmental disorders but its relationship to perceptual timing of multisensory events (auditory, visual, and tactile) is not known, even in healthy populations. The purpose of this study was to characterize temporal integration of sensory modalities within a young healthy population. Twenty-five adults participated in TBW measurements with three different modalities. 100-ms stimuli (auditory: beep; visual: flash; tactile: vibration) were presented with various onset asynchrony (-500 to 500 ms) between two stimuli (AV: auditory-visual; AT: auditory-tactile; VT: visual-tactile). Participants were instructed to select “simultaneous” or “asynchronous” responses. Results show that the TBW for the AV condition ranged from 222 to 689 ms (mean ± SD = 418 ± 103), the AT condition ranged from 164 to 666 ms (376 ± 130), and the VT condition ranged from 70 to 751 ms (279 ± 131). These findings suggest that deficits in multisensory temporal function may factor into perceptual and cognitive weaknesses that characterize clinical disorders, raising the possibility that it may be a contributing pathologic factor in these conditions.
The effect of competitor rhythmic structure when recalling vowels in a complex listening environment
Authors: Pearson Dylan V. , Shen Yi , Kidd Gary R. , McAuley J Devin
Published: May 2022

Research has shown that the rhythmic structure of speech is relevant to listening outcomes in complex environments. Several studies have shown that an intact, natural target rhythm facilitates listeners’ perception of auditory signals. However, less is known about the effect of competitor signal rhythmic structure on target recognition. The current study uses a synthetic vowel identification paradigm to investigate the influence of the rhythmic structure of to-be-ignored competing signals on listeners’ ability to identify speech information in a target signal. Listeners were tasked with identifying the last three vowels of target sequences of varying length presented alongside competing sequences consisting of either vowel-like harmonic tone complexes or similar vowels. The inter-onset-intervals in these sequences were manipulated to create conditions where the internal rhythm of the sequences was either isochronous or irregular. Competitor rhythm was found to be a significant factor for target recognition only with the vowel-sequence competitors. Isochronous target vowel recognition was better for vowel-sequence competitors with an irregular rhythm than with a regular (isochronous) rhythm. The results of this study highlight (1) the relevance of the rhythmic structure in selective listening tasks and (2) the importance of target and competitor similarity in determining the influence of competitor rhythm.
Quantifying impacts of hearing protection devices on sound localization in azimuth and elevation: Toward predictors of performance
Authors: Brown Andrew D. , Greene Nathaniel , Audet David J. , McCallick Caylin R. , Sammeth Carol A. , Anderson David A. , Rule Gregory T. , Argo Theodore F.
Published: May 2022

Modern hearing protection devices (HPDs) effectively mitigate the risk of noise-induced hearing loss when used as intended, and some even preserve the audibility of low-to-moderate-intensity sounds. Nonetheless, negative auditory perceptual side-effects continue to limit usability in critical settings. Most notably, dozens of studies have shown that HPDs lead to significant errors in sound source localization. Several studies have specifically linked such errors to HPD-induced distortions of the spectra of transmitted signals. Here we provide an update on a multi-site study designed to capture patterns in sound localization errors (among other impacts) across different classes of HPDs, toward validation of acoustic predictors of HPD performance. At two independent study sites, human listeners localized brief broadband signals with open ears (control) and during use of passive and active earplug and earmuff-style devices. Sources spanning 360° in azimuth and −30° to + 60° in elevation enabled measurement, via wireless head-tracking, of 2-D localization error across a broad range of source locations. New metrics integrating these measurements with acoustic data, obtained via standardized HPD test fixtures as well as in-ear microphones designed to capture individual variation in HPD impacts, will support application-specific selection of existing HPDs and inform the design of new HPDs.
Profile analysis and ripple discrimination at high frequencies
Authors: Guest Daniel R. , Oxenham Andrew J.
Published: May 2022

Profile analysis and spectrotemporal ripple discrimination are psychoacoustic tasks used to probe the auditory system’s spectral and intensity resolution. In the present experiment, we compared performance at low- and high-frequencies in four related psychoacoustic tasks: level discrimination, profile analysis, spectrotemporal ripple detection, and spectrotemporal ripple direction discrimination. The level discrimination and ripple detection tasks were designed so that cues from single auditory filters were sufficient for performing the tasks. The profile analysis and ripple direction discrimination tasks were designed to render cues from single auditory filters insufficient to perform the tasks. Based on data from a group of ∼20 young normal-hearing, listeners, we found that profile analysis was markedly worse at high-frequencies than low-frequencies, even when accounting for differences in level discrimination at low- and high-frequencies. In contrast, no significant differences were observed between low- and high-frequencies for either the ripple detection or ripple direction discrimination tasks. We further analyzed our behavioral data using computational simulations of auditory-nerve and midbrain responses. This analysis suggested that differences in performance at low- and high-frequencies cannot be explained at the level of the auditory periphery, but instead emerge at more central loci. [Work supported by NIH grants F31 DC019247 and R01 DC005216.]
Determination of radiated sound power from acoustic sources using the VBSP method and a transparent acoustic boundary
Authors: Bacon Ian C. , Campbell Gibson H. , Ebeling John C. , Sommerfeldt Scott D. , Blotter Jonathan D.
Published: May 2022

Significant progress has been made to develop a vibration-based sound power (VBSP) method as an alternative means to determine the radiated acoustic energy from structures. This method has been validated for flat plates, cylindrical-shells, simple curved plates, and arbitrarily curved panels. However, many acoustic sources, such as a blender or motor, have sound power contributions that are enclosed within the structure and therefore cannot be scanned properly using a vibrometer. A rigid enclosure with a single mylar face for one side of the enclosure was fabricated to enclose the acoustic source, such as an “acoustic tent” around the structure of interest, so that the VBSP method could be applied to and obtain the radiated sound power. Due to the nature of the sources, this application of the VBSP method will have limitations that are not present in the aforementioned work. A calibration curve was developed to account for the effects that the tent had on the sources used for testing and used to correct the experimental VBSP sound power measurements from the acoustic tent. Results will be shown comparing the sound power obtained from the VBSP method with the sound power of the source in a reverberation chamber using ISO 3741. Funding for this work was provided by the National Science Foundation (NSF). [Funding for this work was provided by the National Science Foundation (NSF).]
A geometrical approach to estimate the modal radiation efficiency of complex structures
Authors: García A. Carlos , Dauchez Nicolas , Lefebvre Gautier
Published: May 2022

The radiation efficiency of plates has been the study of many works. The rectangular simply supported plate is the most studied case, followed by the circular one. Analytical formulas and approximations for multiple boundary conditions, baffled and unbaffled cases have been the subject of study for decades. For a structure with a complex shape, numerical methods are appropriated such as FEM and BEM approaches. Semi-analytical based on Rayleigh’s integral also appear in the literature to calculate the radiation, mixed with the surface velocity calculated by FEM; they are easy to implement but they are resource consuming as large matrices are presented. In this work, we present a method for estimating the modal radiation efficiency of simply supported and clamped complex plates, based on the theory of Greenspan for circular radiators and with a geometrical approach.
The acquisition of gestural timing
Authors: Howson Phil J.
Published: May 2022

Motor plans are complex and consist not only of constriction location and degree, but also gestural timing. For children to acquire adult-like speech, they need to acquire complex timing relationships that can result in delayed acquisition. To examine this phenomenon, we examined long-distance timing patterns for English liquids, /r, l/, and short-distance timing patterns for fricatives, /θ, s, ʃ/, for 5- and 8-year-olds compared to adults. To examine the long-distance timing of liquids, I used an AV-Gated paradigm where participants saw clips of speech and predicted an upcoming /r/ or /d/ (Exp1a) or upcoming /l/ or /d/ (Exp1b). The results revealed long distance timing sequences for /r/ and /l/, with the timing for /r/ extending to at least five segments prior and /l/ 2 segments prior. However, 5-year-olds exhibited extremely long-distance timing for both /r/ and /l/, while 8-year-olds had longer distance timing for /r/ and /l/, but still not adult-like timing. Results suggest long-distance timing must be acquired. In the second experiment, we examined the dynamic COG of fricatives from 5- and 8-year-olds compared to adults. Dynamic COG results revealed significantly more vowel induced variability for/θ/ for adults than for 5- and 8-year-olds, with similar degrees of variability for /s, ʃ/. Overall, the results suggest that acquisition oftiming increases the relative complexity of acquisition, and that segment specific articulation interferes with acquisition of timing in different ways.
What long-distance coarticulation can tell us about coarticulatory development
Authors: Cychosz Margaret
Published: May 2022

It is widely acknowledged that children’s speech gestures overlap more than adults’ in spoken language. Unlike coarticulation in adult speech, which is largely planned (Whalen, 1990), children’s coarticulation appears to stem from their (1) protracted tongue-jaw coordination and (2) inexperience with language. For example, 4- to 7-year-olds with greater phonological awareness tend to coarticulate less within syllables (Noiray, et al., 2019). Long-distance, inter-morphemic coarticulation is another way to demonstrate that children coarticulate for different reasons than adults: by comparing across multiple segments, and contrasting coarticulation within versus across word morphemes, we can invoke speech planning, not just motor control. Since children’s coarticulation is assumed to reflect inexperience and lack of planning, they should coarticulate less than adults in longer-distance environments. N = 51 5- to 10-year-old children and 10 female adults, all bilingual South Bolivian Quechua-Spanish speakers, completed a Quechua morphological elicitation task. Inter-syllabic coarticulation was quantified using a whole-spectrum measure within bare stems (within-morpheme) and inflected nouns (across-morpheme). Results were compared to speakers’ intra-syllabic coarticulation and showed that while children, unsurprisingly, coarticulate more within syllables, they anticipate segments at a longer distance (inter-syllabic and across morphemes) less than adults, only approximating adult-like patterns around age 9.
Anticipatory vowel coarticulation in child versus adult speech and a model of developmental change
Authors: Redford Melissa A. , Davis Maya , Diantoro Carissa A. , Kallay Jeffrey
Published: May 2022

There is by now extensive evidence to suggest that coarticulatory domains are at least as large in children’s speech as in adults’ speech. A series of four experiments that investigated the temporal domain of anticipatory vowel articulation in speech elicited from school-aged children and college-aged adults under different conditions (random elicitation, repetitive elicitation, spontaneous speech) confirms previous findings and suggests a new one: anticipatory cues to an upcoming vowel ramp up more quickly in adult’s speech compared to children’s speech. Both the established and new findings can be modeled with reference to the windows that govern path selection in perceptual-motor space. Specifically, the findings are modeled as a developmental decrease in the size of a lookback window, to be interpreted as a developmental increase in inhibitory motor control. [Work supported by NIH under grant R01HD087452.]
Development tools for deep learning models of acoustical signal processing
Authors: Hawley Scott H.
Published: May 2022

We present a survey of available frameworks for developing acoustical signal processing models based on deep neural networks. Given that this is a dynamic space with new frameworks, libraries, and even companies appearing on timescales measured in months, we provide an up-to-date assessment of the strength, popularity, and near-future directions of several tools and platforms available for research and product deployment for deep learning models of audio signal processing. Similarly, those new to these spaces may be unaware of software systems that will allow them to obtain and interrogate results more quickly and easily, while also integrating the nearly state-of-the-art optimization methods. Included tools, packages and platforms include PyTorch, Tensorflow, Keras, JAX, fastai, PyTorch Lightning, Julia, nbdev, HuggingFace, Weights and Biases, and Gradio. Examples will be drawn from the speaker's recent research publications in musical signal processing and computer vision applied to musical acoustics, as well as recent work by others. The goal of the talk is to provide acoustics researchers, educators, students with a set of helpful possibilities for pursuing and improving their understanding, research practices, and communications.
Bayesian approach to passive receiver localization in a randomly scattered sound field
Authors: Wilson D. Keith , Pettit Chris L. , Ostashev Vladimir , Fragoso Anthony
Published: May 2022

A Bayesian approach is described for localizing sources and receivers in a randomly scattered sound field, for which the complex Wishart distribution represents the joint distribution of the signals at multiple, arbitrarily separated receivers. The signals are assumed to be narrowband and fully saturated by scattering from homogeneous turbulence (or similar scattering processes) as they propagate along line-of-sight paths to the receivers. Here, we consider a scenario in which there is an array of receivers at known locations, a source of opportunity with unknown amplitude at an unknown location, and a single receiver at an unknown location. The objective is to passively determine the unknown receiver location even though the source characteristics are not initially known. A slice-sampling strategy is found to be suitable for solving the problem. Simulations show that a small number of independent signal samples at the receivers initially enables the unknown receiver to be localized on a circle of constant amplitude around the source. With more samples, the correlation characteristics of the field enable full determination of the unknown receiver location.
Exploiting spatio-temporal spectral features of the indoor acoustic field for sound source localization
Authors: Gandhi Pratik , Uhunsere Nathan , Paul Adonai , Chandra Kavitha , Thompson Charles
Published: May 2022

The estimation and classification of spectral features of the spatio-temporal acoustic field in a reverberant rectangular enclosure is undertaken with application to localizing sound sources. The field is constructed using an image source model of the impulse response that captures the acoustic properties of the enclosure boundaries. The received field is examined considering linear and randomly distributed array configurations and spectral peaks are characterized to derive a set of features for classification and source identification. The effects of noise generated by the environment and the diffuse field from multiple reflections is distinguished.
PLASTIC: Pressure and location-based acoustic sensing touch interface using classification
Authors: Anderson David A.
Published: May 2022

A method is described for developing a pressure sensor panel that uses a single small electromechanical exciter, delivering a sawtooth wave, and a single sensor attached to a panel or structure. A trained classifier is able to recognize the pressure and location of a finger-sized object pressing on the panel based on the characteristics of the waveform detected at the sensor. The classification results of three experiments are reported: 55 virtual buttons on a panel, the pressure classification sensitivity of a single virtual button, and the location classification resolution of a tightly packed grid of points. All three experiments show excellent accuracy (99.7%, 85.2%, 96.0%, respectively) using a simple trained linear SVM classifier with a 70/30 training/validation data ratio, demonstrating that the PLASTIC method is an effective method for classifying the location and pressure of a touch on a panel or structure.
Machine learning-based room acoustics using flow maps and physics-informed neural networks
Authors: Borrel-Jensen Nikolas , Engsig-Karup Allan P. , Jeong Cheol-Ho
Published: May 2022

The development of efficient and accurate numerical methods for simulating realistic sound in virtual environments—such as computer games and VR/AR—has been an active research area for the last decades. However, handling dynamic scenes with many moving sources is still challenging due to intractable storage requirements and extensive computation time. A recently proposed physics-informed neural network (PINN) approach learns a compact and efficient surrogate model with parameterized moving sources and impedance boundaries on a grid-less 1-D domain. Contrary to traditional “black-box” deep learning, PINNs minimize the residuals of the governing equations through the loss function. We will extend this work using flow maps implemented as Residual Networks (ResNets). ResNets are interpreted from a dynamic systems perspective as ordinary differential equations that can be used as building blocks to approximate the governing equations in time. We will examine the pros and cons of ResNets in acoustics and compare them with state-of-the-art numerical methods and vanilla feed-forward neural networks in terms of accuracy and efficiency.