bluuebunny/crossref_metadata_2025 huggingface dataset:
Using machine learning to evaluate the fidelity of acoustic simulations
Authors: Miller Andrew J. , Sommerfeldt Scott D. , Blotter Jonathan D.
Published: December 2020

There has been a longstanding tradeoff in evaluating the quality or fidelity of sound recordings: subjective listening tests are time consuming and expensive, but objective measures often fail to capture the nuances of human perception. The research presented here seeks to address this problem by investigating the use of machine learning to evaluate the fidelity of acoustic simulations. To begin, we created a dataset of recordings representing varying levels of audio fidelity. Participants listened to each of the recordings and subjectively classified the perceived fidelity. Various audio features were extracted from the recordings, including several psychoacoustic sound quality metrics and other features commonly used in speech recognition/assessment and music genre classification. These features were input to various machine learning algorithms to test which best modeled the human classifications. A logistic regression model was initially determined to be the most advantageous, dependent on using binary classification. Introducing a reference sound, and calculating each feature relative to the reference, significantly improved accuracy.
Comparisons of integral equations and theoretical models of scattering from layered, rough seafloors
Authors: Olson Derek R.
Published: December 2020

Several models have been proposed for acoustic scattering from layered seafloors with rough interfaces. These include the small perturbation method, the Kirchhoff approximation, and three different small-slope approximations. In some situations, all of these models disagree. It is therefore advantageous to understand which model is appropriate to use in these circumstances. In this work, we use the integral equation to obtain exact, Monte-Carlo estimates of the reflection coefficient and scattering cross section. The exact results is compared to models for a single layer with a rough water-sediment interface, and a flat sediment-basement interface. It is found that the method of Jackson and Olson performs the best out of all models, although some of them agree when the rms roughness is small compared to the wavelength.
Graduate programs in acoustics at the University of Salford, United Kingdom
Authors: Hargreaves Jonathan A.
Published: December 2020

Salford is one of the UK's leading centers for research and teaching in acoustics and audio. The courses are delivered by a research-active academic team at the very pinnacle of the profession, with an attractive staff to student ratio. Our taught courses are well-established and well-respected—we have offered postgraduate programs in acoustics since 1999. By studying with us, you will be joining a community of alumni working at the heart of many leading sound and acoustics-focused companies and organizations throughout the world. In addition, we offer MPhil and PhD programs, for those wishing to follow a purely research track. Our courses are suitable for numerate science graduates, who wish to make the transfer into the sound and acoustics industry. Study can be conducted full or part-time and can be delivered on-campus or via distance learning. Building on engineering fundamentals, it provides you with the specialist expert knowledge and a practical skill set, leaving you ready to develop a career as a future leader in audio technology or environment acoustics.
Graduate research and education in architectural acoustics at Rensselaer Polytechnic Institute
Authors: Xiang Ning , Braasch Jonas , Brooks Todd
Published: December 2020

The Graduate Program in Architectural Acoustics has been constantly advanced from its inception in 1998 with an ambitious mission of educating future experts and leaders in architectural acoustics, due to the rapid pace of change in the fields of architectural-, physical-, and psycho-acoustics. Recent years the program's pedagogy using “STEM” (science, technology, engineering, and mathematics) methods has been proven to be effective and productive, including intensive, integrative hands-on experimental components that integrate architectural acoustics theory and practice. The graduate program has recruited graduate students from a variety of disciplines including individuals with B.S., B.Arch. or B.A. degrees in Mathematics, Physics, Engineering, Architecture, Electronic Media, Sound Recording, Music and related fields. Graduate students under this pedagogy and research environment have been succeed in the rapidly changing field. RPI's Graduate Program in Architectural Acoustics has since graduated more than 120 graduates with both M.S. and Ph.D. degrees. Under the guidance of the faculty members they have also actively contributed to the program's research in architectural acoustics, communication acoustics, psycho-acoustics, signal processing in acoustics as well as our scientific exploration at the intersection of cutting edge research and traditional architecture/music culture. This paper illuminates the evolution and growth of the graduate program.
Effects of face masks and speaking style on audio-visual speech perception and memory
Authors: Keerstock Sandie , Meemann Kirsten , Ransom Sarah M. , Smiljanic Rajka
Published: December 2020

Though necessary, protective mask wearing in response to the Covid-19 pandemic presents communication challenges. Speech produced through these masks is quieter, muffled, and lacks important visual cues for listeners. The present study examines how such loss of visual information and signal degradation affects intelligibility and auditory memory of non-native speech. Additionally, we examined whether clear speaking style can alleviate some perceptual difficulty for masked speech. One non-native English speaker recorded short, educationally relevant video clips in three conditions: casual speech without a mask, and casual and clear speech with a mask. In an online study, native English listeners were presented with 15 video clips in each of the three mask / style conditions and transcribed what they heard. Following each condition, listeners answered questions about the content of the clips. Word recognition and memory accuracy will be analyzed. Detailed acoustic analyses will be conducted to assess how face masks and speaking style affect speech production. The results will allow us to quantify speech communication challenges arising from the widespread use of masks. The findings will have implications for communication in classrooms and hospitals where listeners have to understand teachers and healthcare providers, often time non-native speakers, through their protective barriers.
Impact of social distancing on persons with sensory loss during COVID-19 pandemic
Authors: Nelson Peggy , Wu Walter Yueh-Hsun , Oeding Kristi , Anderson Elizabeth , Teece Katherine , Legge Gordon
Published: December 2020

Recent mandates for social distancing due to the COVID-19 pandemic have had significant effects on the lives of older persons. Social distancing might have unequal effects on the lives of people with hearing impairment and vision impairment, possibly affecting their emotional well-being. We remotely surveyed 55 persons between the ages of 57–80 years (13 who were legally blind, 24 with significant hearing loss, and 18 healthy controls.) Initial surveys took place in April as shutdowns were mandated; these included current and retrospective responses concerning pre-pandemic conditions. Subsequent surveys of current experiences were conducted approximately monthly. Survey items included: number of weekly in-person and electronic interactions, satisfaction with access to communication, worry/concern levels, and effects of physical distancing and mask wearing on communication and stress. We noted an initial substantial reduction of in-person interactions for all groups, remaining low throughout. While remote electronic communications increased initially, electronic interactions for persons with sensory loss remained steady over time and for some these even decreased. Persons with hearing loss reported significant communication challenges due to mask wearing; persons with vision loss reported significant loss of connection due to physical distancing. Results show both widespread effects and specific effects on those with sensory loss.
Assessing how face masks affect speech intelligibility
Authors: Randazzo Melissa , Priefer Ryan , Koenig Laura
Published: December 2020

To limit transmission of Covid-19, the Centers for Disease Control recommends covering the mouth and nose with a mask while interacting in public. Although face masks protect public health by containing respiratory aerosols and droplets, they can hinder speech perception by filtering the acoustic signal. Here, we assess how masks affect speech intelligibility in audio-only conditions. Four young adult native speakers of American English, naÃ¯ve to the purpose of the experiment, produced short low-probability sentences in four conditions: dual-layer cloth, disposable surgical, N95, and no mask. Multitalker babble was applied to the stimuli. Listeners recruited through Amazon Mechanical Turk rated the intelligibility of the sentences, with speaker and mask condition counterbalanced. Along with obtaining overall intelligibility ratings as a percentage of words recognized, we will also compute intelligibility for consonants that are known to be differentiated by high-frequency spectral cues, and assess the long-term average spectra for the different mask types. We hope that the information from this study will help us understand the impact of masks on speech perception. Going forward, we will carry out parallel experiments with older individuals and those with hearing loss.
Multiclass sound event detection for respiratory disease diagnosis
Authors: Grant Drew , McLane Ian , West James
Published: December 2020

Recordings from daily life contain a mix of sound types such as speech, coughing sounds, breathing sounds, and environmental noise, which provide a wealth of information related to linguistic messages, acoustic scenes, and health. These sounds in their unprocessed form overlap in both time and frequency domains, posing challenges to current methods for information extraction and analysis. To address this challenge, we introduce a novel multiclass sound event detection system that discriminates between speech, coughs, breathing, and other miscellaneous sounds (e.g., dogs barking, toilets flushing, babies crying) in the Coswara database, a crowdsourced database using a website application launched in response to COVID-19. This method extracts a feature set that includes Zero Crossing Rates, Short-Term Energy, and Mel-Frequency Cepstral Coefficients and uses Random Forests for multiclass classification. Preliminary results of the system yield a balanced accuracy of 87.5% detecting between speech, coughs, breathing, and other miscellaneous sounds. Using the multiclass sound event detection system, a time and acoustic-mediated forced-alignment technique is employed to discriminate complex sounds in real-time. We envision that the system could be used on devices with existing information extraction methods formonitoring respiratory diseases, such as pneumonia, pertussis, and COVID-19.
Atom music: Acoustical realizations of the atomic world through sonification
Authors: Linz Jill A.
Published: December 2020

Atom Music is an experimental music project that uses music synthesis techniques to create sonifications of atomic structure. It was first presented at the 178th meeting of ASA in San Diego, CA. Several realizations of atom music as it applies to science and to art have occurred with collaborations using both the atom tones and atom scales. Atom Music has become a unique way for people to learn about atoms and molecules. The idea of creating tones unique to each element as well as musical scales also based on each element has inspired people from many disciplines. This talk will focus on two separate collaborative endeavors. The first is an artistic collaboration that began as an interactive educational experience and resulted in six separate sound experiences. The second collaboration resulted in the creation of unique tones for each element, which can then be used as an acoustical periodic chart. The uses for this are varied. Several examples of how the acoustical periodic chart can be used will be discussed.
Metamaterial solutions for noise management in hospital settings
Authors: Chisari Letizia , Bonoldi Lorenzo , Memoli Gianluca
Published: December 2020

Hospital were noisy places even before the recent pandemic, but the need to save lives have made them even noisier, with potential impacts on patients and staff. In this work, we present a feasibility study on the use of acoustic metamaterials in this context. Acoustic metasurfaces of different geometries, labyrinthine or not, have been tested using a commercial package for finite-element simulations, both separately and in composite combinations. The results are compared and benchmarked with measurements, to optimise the materials' ability to control sound transmission while allowing air to flow through. A discussion on the limitations and the perspectives of this approach completes the study.
Declaration and verification of product noise emission levels and the new ANSI/ASA S12.61 standard
Authors: Nobile Matthew
Published: December 2020

The primary goal of any product noise declaration (or “labeling”) initiative is to enable consumers and other purchasers to make informed buying decisions. It doesn't matter if the product is relatively low-noise and the concern is one of annoyance or if the product is very loud and the concern is one of noise hazard. The purchaser still needs to know the noise level in order to make a prudent choice. This should be easy, right? We bring the product into a test lab and measure its sound power level. Then we report that number, correct? Yes, that would be true for testing and reporting a single unit. The problem comes when we are attempting to declare (label) an entire production series ( “batch”). The 100 000 Model XYZ leaf blowers will each have slightly different levels. Suddenly we are talking about population parameters, sampling, and (because we also have to verify that the declared value is correct) statistical inference and probability of acceptance. It soon gets complicated. This paper will go over some of the basic concepts needed to understand product noise declarations and verifications and will describe the newly published ANSI/ASA standard S12.61 that sets forth the requirements for making these.
Perceptual consequences of spectral manipulations for cisgender and transgender speakers
Authors: Merritt Brooke , Bent Tessa
Published: December 2020

Fundamental frequency and vowel formant frequencies are reportedly the most salient acoustic-phonetic cues used to judge speaker gender. However, the influence of these cues on listeners' extraction of gender and lexical information from spontaneous speech is poorly understood. This study evaluated the perceptual impacts of modifying fundamental frequency and formant frequencies in spontaneously produced speech by cisgender and transgender individuals. Spontaneous speech samples from 12 transgender (6 transfeminine and 6 transmasculine) and 12 cisgender (6 male and 6 female) speakers were included in three tasks: a speech-in-noise intelligibility task, a two-alternative forced-choice gender identification task, and a masculinity/femininity rating task, in one of two conditions: an unmodified condition or a modified condition in which fundamental and formant frequencies were manipulated to fall within either prototypical cisgender male/female range for the transgender speakers or an intermediate, gender-ambiguous range for the cisgender speakers. Results suggest shifting fundamental frequency and formant frequencies toward prototypically male/female ranges in connected speech can effectively alter listeners' gender identification judgements, but these variables alone may not be sufficient to alter perceived vocal masculinity/femininity to within typical cisgender ranges for transgender speakers. Further, strategies used by transfeminine speakers to achieve gender-congruent voice may negatively affect speech intelligibility.
Effect of hesitation sound phonetic quality on perception of language fluency
Authors: Trebon Tillena , Baese-Berk Melissa M.
Published: December 2020

Nonnative speech differs from native speech in various ways, including different pausing patterns. There are two types of pauses: filled and unfilled. Unfilled pauses are silent. During filled pauses, speakers make a sound. Different languages use different sounds for filled pauses; this is described as phonetic quality. English speakers use “uh” to hesitate. Spanish speakers use “eh” to hesitate. When the phonetic quality of a hesitation sound is consistent with the hesitation sound used by native speakers, the hesitation sound is “native.” A hesitation sound with phonetic quality inconsistent with a native speaker hesitation sound is “non-native.” Production studies show that proficiency and speech community influence whether second language speakers produce native or nonnative hesitation sounds. However, no study has investigated the perceptual consequences using nonnative versus native hesitation sounds. This study investigates the effect of hesitation sound phonetic quality on perception of language fluency by comparing fluency ratings of sentences with nonnative hesitation sounds to fluency ratings of sentences with native hesitation sounds. This research answers questions such as: Do listeners judge non-native speakers to be less fluent when speakers produce non-native hesitation sounds? Is it beneficial for L2 learners to use native hesitation sounds to achieve perceived fluency?
Different facial cues for different speech styles in Mandarin tone articulation
Authors: Garg Saurabh , Tang Lisa , Hamarneh Ghassan , Jongman Allard , Sereno Joan , Wang Yue
Published: December 2020

Research has shown that facial articulatory cues aid speech perception. However, how such cues are employed in different speech styles remains unclear. This study examined facial articulatory features of Mandarin tones in clear versus conversational speech styles produced by 20 native Mandarin speakers. Using computer-vision and image-processing techniques, keypoints representing each speaker's head, eyebrow and lips were identified on video, and their movement trajectories during tone productions were tracked. Thirty-three features based on distance, time and kinematics (e.g., velocity) were subsequently computed to characterize the movements. Random forest and t-test analyses were then conducted to identify the significant features between the two speech styles. Results reveal that, across tones, clear relative to conversational style involves greater movement distance and velocity, reaching articulatory targets faster. Individual tone analyses further indicate that the faster target approximation in clear speech occurs for contour tones (2-4) but not the flat tone 1. The increase in distance and velocity in clear speech is reflected on more features for the most dynamic tone 3 than for the other tones. These results suggest that clear-speech modifications for tones can be exhibited through facial movements, involving hyper-articulation across tones and tone-specific adjustments aligned with individual tone trajectories.
Users' head movement obtained from avatars in social VR applications
Authors: Farr Chloë , Liu Yadong , Gick Bryan
Published: December 2020

Virtual Reality has been endorsed as a highly beneficial tool for face and hand-head gesture research [Sidenmark and Gellersen (2019), ACM Trans. Computer-Human Interaction 27(4)]. Studies have shown [i.e., Xu, X. et al., J. Biomech. 48(4), 721–724 (2015)] that avatars accurately simulate user movements and allow researchers to obtain users' movements remotely without in-person contact or external recordings taken by the users. This study examines head movements of avatars in three popular social VR applications (Altspace, Oculus Home, and vTime XR) using Openface 2.0 [Baltrusaitis et al., in 13th IEEE International Conference on Automatic Face & Gesture Recognition (FG 2018) (2018), pp. 59–66], software that measures head movements in a video. In each of these three platforms, we recorded a user making a sequence of head movements, rotating side-to-side and up-and-down to their maximum extension. Pilot results show that avatar movements in all three apps could be tracked by OpenFace 2.0. Further analysis will include which application's avatars best represent the user's real-time movements. This study provides insight into speech behaviour research and whether user movements are analysable via an avatar, without in-person contact or lab facilities under the new COVID-19 regulations.
Integration of soft-robotics and deep learning to assess the coordinated emission and reception dynamics in hipposiderid bats
Authors: Zhang Shuxin , Yin Xiaoyan , Wang Ruihao , Müller Rolf
Published: December 2020

Some echolocating bat species with sophisticated biosonar systems such as the Old World leaf-nosed bats (Hipposideridae) change the shapes of their ultrasound emission (noseleaves) and reception baffles (pinnae) during the diffraction of the incoming and outgoing acoustic waves. Our prior research has shown that these noseleaf and pinna deformations are coordinated, but a functional significance for this coordination has yet to be demonstrated. Here, we combine a soft-robotic reproduction of the dynamic biosonar periphery in hipposiderid bats with deep neural networks to assess the impact of the coordination between the emission and reception dynamics. The biomimetic noseleaves and pinna are equipped with soft pneumatic actuators to accomplish life-like deformations. Control over this system allows us to reproduce not only the coordination patterns seen in bats but also other possible patterns that appear to be absent in bats. Comparing the suitability of these different coordination schemes between emission and reception could be used to assess which coordination pattern is best suited for a given task. As a first task, a direction finding paradigm has been selected for this assessment and work on identifying a network architecture that can take advantage of the dynamic nature of the echoes is currently in progress.
Development of foliage echo simulations based on generative adversarial networks
Authors: Goldsworthy Michael , Müller Rolf
Published: December 2020

Through the use of biosonar, bats exhibit extraordinary navigation and localization capabilities, vastly outperforming any engineered sonar systems, especially while traversing complex cluttered environments, such as dense foliage. Therefore, computer simulation of foliage echoes has great potential to aid in studying and understanding bat biosonar, and thus may aid the development of technologies that deal with cluttered acoustic signals in air as well as in water. Generative Adversarial Networks (GANs) are a machine learning tool that have produced useful results in many computer vision tasks, but have only relatively recently been applied to acoustic signals. The work presented here uses GANs trained on a large dataset of recorded leaf echoes to create plausible acoustic models of tree echoes from the generation of impulse responses from single leaves placed in virtual 3-D space by tree generation algorithms. The generated foliage echoes show significant similarity to real foliage echoes and outperform previous simulation methods in terms of the realism of the results. These simulated echoes may be used to devise navigation methods that could be transferred to real robotic systems. In future work the focus will be on generating entire environment impulse responses in a variety of bat habitats.
Acoustical design challenges of colossal public interiors
Authors: Sü Gül Zühre , Caliskan Mehmet , Bora Ozyurt Zeynep
Published: December 2020

In this study, a long-term experience with public buildings are discussed over architectural and acoustical parameters. Different codes and standards apply for a variety of public buildings in different countries. The criteria are generally set and can be satisfied for sound insulation metrics without an over-use of material. However, room acoustics design is always a challenge especially when the indoor space is excessive in scale, yet the criteria are also not always well-defined. In this contemporary era, the architectural styles emphasize even more the flexibility and the flow of spaces by connected volumes. This approach commonly ends up with linked circulation zones, huge foyers or almost monumental entrances. To exemplify and further discuss some of these cases, this study is framed around two buildings of different functions. The first case is Heydar Aliyev Center in Azerbaijan, with coupled inner galleries of circulation of museum and library zones and a grand foyer of the auditorium. Second case is the Kuwait International Airport Terminal possessing a grandeur of interior voids of check-in and concourse halls. For both cases the optimization of excessive reverberation is the major issue in a struggle of not overly applying acoustical materials. The selected indoor spaces at some locations demonstrate almost a free-field behavior. Accordingly, this study questions the use of common parameters, including reverberation time, strength and sound levels and the setting of proper criteria for such large public interiors.
Near real time passive acoustic monitoring in the Santa Barbara Channel
Authors: Wood Megan , Baumgartner Mark , Visalli Morgan , Širović Ana
Published: December 2020

The coastal waters off Southern California are feeding grounds for a variety of baleen whale species including blue whales, fin whales, and humpback whales. The feeding grounds overlap with highly used shipping lanes in the Santa Barbara Channel (SBC), increasing the risk of ship-whale interactions. In November 2019, a buoy equipped with a digital acoustic monitoring (DMON) instrument was deployed in the SBC and has been actively recording sounds and transmitting detection information in near real time since then. Data are transmitted in fifteen-minute summary periods of detected pitch tracks, which are reviewed by an analyst onshore for blue, fin, and humpback whale calls. Humpback whales were the most prolific callers, with detection rates reaching 80% of daily summary periods, whereas fin and blue whales rarely exceeded 20%. Baleen whale detections were low in late fall, with humpback whale detections increasing throughout winter and in spring and blue whale detections peaking during the summer. As part of the Benioff Ocean Initiative project to reduce whale strikes, these data are combined with visual surveys in the SBC and habitat models to produce a whale presence metric. This metric can be used by regional stakeholders to guide policy decisions and enhance conservation efforts.
Parametric imaging of ultrasonic backscatter of fixed sheep brain
Authors: Labuda Cecille , Newman Will R. , Hoffmeister Brent K.
Published: December 2020

Ultrasound backscatter properties of aggregate brain tissue are available in the literature, however, reporting on the spatial variation of backscatter over tissue volumes is limited. The spatial variation of the apparent integrated backscatter (AIB) and the logarithmic backscatter amplitude decay constant (BADCL) was characterized for 1-cm thick samples from the coronal, sagittal and transverse anatomic planes of fixed sheep brain. Submerged samples were exposed to ultrasound using broadband transducers with center frequencies of 3.5, 5.0, 7.5, and 10 MHz by scanning over the samples in half-beamwidth step sizes to measure the backscattered signal. Parametric images of the AIB and BADCL showed a clear correlation between morphological features in the tissue samples and the images with the AIB giving the better representation of the overall tissue structure. Over all samples and frequencies, the range of the spatial mean of the AIB was −77.7 to −59.8 dB with the standard deviation ranging from 3.14 to 6.99 dB. The spatial mean of the BADCL ranged from 0.0350 to 0.152 μs−1 with standard deviations ranging from 0.0820 to 0.111 μs−1. For both parameters, morphological features of the tissue become more distinctive with increasing frequency.
Influence of phononic material filters on nonlinear ultrasound measurements
Authors: Smith Elizabeth , Matlack Kathryn
Published: December 2020

Nonlinear ultrasound (NLU) is a nondestructive evaluation method that is sensitive to microscopic material damage, which is highly desirable information to prevent failure of critical components. The damage is correlated to the second harmonic generated by a sinusoidal signal as it propagates through a material. However, measurements of the second harmonic are plagued by experimentally induced nonlinearities and require careful calibrations that have limited them to laboratory measurements. Here, we propose the use of phononic materials with ultrasonic filtering properties to reduce extraneous nonlinearities. Finite element simulations were used to design phononic materials to transmit an ultrasonic wave but forbid the propagation of its second harmonic. Phononic filters were fabricated with additive manufacturing and experimentally characterized in the ultrasonic regime. Results show that the phononic materials behave as low-pass filters, where the cut-off frequency is controlled by the phononic material’s unit cell geometry. Filters were then incorporated into NLU measurements. Experimental results show that the phononic filter decreases the measured second harmonic amplitude and removes extraneous nonlinearities from the transducer, therefore better isolating second harmonic generation in a material. This work suggests that phononic materials could enable in situ NLU measurements and of critical components.
Numerical study of an acoustic leaky wave antenna
Authors: Bustamante Omar A. , Romero-Vivas Eduardo , Velasco-Segura Roberto
Published: December 2020

Acoustic leaky wave antennas (LWAs), introduced as frequency scanning devices, have been studied in recent years for Direction of Arrival (DOA) and highly directional frequency-selective transmission due to their advantages over multi element arrays such as compactness and low-power requirements. This work presents a numerical study through Finite Element Method (FEM) that solves the Helmholtz Equation using code based on the open-source FEniCS Project. The model under study is a one-dimensional acoustic LWA with axysimetric open channels that performs as a transmitter from broadside to endfire directions. We describe the numerical method applied and validate the code with a lumped-element analysis approximation over the frequency range of interest, showing good agreement in the results. Visualization of different aspects of the LWA like the dispersion relation and scattering parameters, among others are presented. Discussion also focus on the scripting possibilities for automation and inspection of large parameter spaces. This approach proves useful when considering termination effects like end-correction or when exploring new designs with irregular geometries that could provide better performing, but where theoretical modeling turns complicated. [Work supported by UNAM-PAPIIT TA100620.]
A finite element model to study the earplug contribution to the objective occlusion effect
Authors: Carillo Kévin , Doutres Olivier , Sgard Franck
Published: December 2020

The use of earplugs is commonly associated with an amplification of low frequency physiological noises in the earcanal referred to as the occlusion effect. In the literature, the type of earplug has been shown to significantly influence the occlusion effect in particular when inserted deeply enough. However, few studies have investigated the physical mechanisms that rule the earplug contribution. Their understanding is necessary to ultimately act on the earplug to reduce the occlusion effect. Classical lumped element models usually simplify the earplug as an impedance connected to the earcanal cavity. Intricate couplings of the earplug with the earcanal wall and the earcanal cavity are thus neglected. Finite element models can account for these couplings and thus make it possible to study the earplug contribution. In this work, the physical mechanisms that explain the earplug contribution to the objective occlusion effect are investigated. For this purpose, a 2-D axi-symmetric finite element model of an outer ear is used. Two types of earplug (foam and silicone) as well as two insertion depths (medium and deep) are considered. The earplug influence is interpreted in terms of volume velocity imposed to the earcanal cavity and related to its mechanical properties and its insertion depth.
Ambisonics and blind source separation in virtual acoustics: Sound field reproduction of separated sources
Authors: Dermagne Louis J. , Gauthier Philippe-Aubert , Berry Alain
Published: December 2020

Blind source separation (BSS) has many applications: sound scene analysis, speech recognition, medical signal processing, etc. However, most of these applications concern the temporal separation of signals. Studies have shown the effectiveness of separation in the ambisonic domain with spherical microphone recordings. Thanks to the ambisonic approach, it is possible to separate the directions of arrival of the sources. As such, BSS becomes a promising tool for sound field reproduction with loudspeakers arrays (WaveField Sythesis or Higher-Order Ambisonics). Thanks to spherical microphone arrays and Ambisonics principle, both spatial and temporal information are available. Therefore, it would be possible to reproduce the individual sound field of each separated source. Thus, one can remove a given source from a recording and reproduce the remaining sound field. The main objective of this work is to reproduce the sound field of one of the captured sources by removing the rest of it (sources or noise). The first part of the paper presents the methods for the BSS and corresponding sound field reproduction. The second part presents simulation results and investigates effect of measurement noise, spatial source separation, and reflection. [Work supported by NSERC Discovery grant.]
Animating sound using neurally multiplexed holograms
Authors: Athanassiadis Athanasios G. , Schlieder Lennart , Melde Kai , Volchkov Valentin , Fischer Peer
Published: December 2020

Acoustic holograms are a simple yet powerful tool to project structured pressure fields for applications including acoustic manipulation, ultrasonic therapy, and compressed sensing. However current holographic projectors lack the ability to dynamically change the pressure field, which is necessary for real-time manipulation and control of acoustically excited systems. A promising solution is to use hybrid projectors: multi-element phased arrays combined with high-resolution static holograms. Such a system was recently built to dynamically translate high-resolution pressure fields for particle manipulation in water. Here, we extend this paradigm and introduce a more general hybrid acoustic projector capable of projecting distinct high-resolution pressure fields using arrays with only a few elements. Each input element excites a distinct output field through a multi-plane hologram, whose phase delays are calculated by representing pixels in each phase plate as neurons in a diffractive neural network. This representation allows us to efficiently multiplex the holograms so that all of the input-output transformations are performed by a single set of static phase plates. We experimentally characterize the output of our device and show that by cycling through the different inputs, the projected acoustic field can be changed in real time, creating an “acoustic animation.”
The production and perception of prevelar/æ/-raising by Canadian and American english speakers
Authors: Sullivan Lisa
Published: December 2020

Pre-velar /æ/-raising occurs when /æ/ is raised before /g/ relative to other contexts. This study examines the extent of phonological conditioning of /æ/-raising between /g/ and /k/ in production and perception. First, I tested the extent to which 18 Canadian and American English speakers raise /æ/ before /g/ (vs. /k d t/) using a wordlist reading task with words containing /æ/ and /ɛ/ in the relevant contexts. Consistent with previous studies (Stanley, 2018; 2019), Canadians, but not Americans, tended to raise /æ/ before /g/. Second, I tested whether the same effect exists in perception using a forced-choice nonce-word identification task with 9-step continua from /æ/ to /ɛ/ before /g/ and /k/. Are speakers who /æ/-raise in production more likely to identify the manipulated vowel as /æ/ before /g/ than /k/, especially when it is ambiguous? Perception has not been tested in previous work, though anecdotal evidence suggests differences in perceptual saliency – Americans, but not Canadians, are aware of /æ/-raising, suggesting that a relationship may exist. Contrary to the anecdotal evidence, there was no correlation between production and perception at the group (nationality) or individual level. However, /æ/ was perceived more before /g/ than /k/ overall, suggesting that /æ/-raising influences perception.
Increased vowel contrast induced by adaptation to a non-uniform auditory perturbation in speech
Authors: Niziolek Caroline A. , Parrell Benjamin
Published: December 2020

When auditory feedback is perturbed in a consistent way, speakers learn to adjust their productions to compensate, a process known as sensorimotor adaptation. Typically, feedback perturbation experiments employ a transformation that targets a single vowel, or that affects all vowels in the same way, resulting in a uniform change across the vowel space (e.g., raising the first formant). Here, we examine speakers’ ability to compensate for a non-uniform perturbation field which was explicitly designed to affect vowel distinctiveness, applying a shift that depended on the vowel being produced. Twenty-five participants were exposed to a “vowel centralization” feedback perturbation in which the first two formant frequencies were shifted towards the center of each participant’s vowel space, making all vowels sound more like schwa. Speakers adapted to this non-uniform shift, learning to produce corner vowels with increased average vowel spacing (AVS) to partially overcome the apparent centralization. This increase in AVS remained significant after the feedback shift was removed, persisting even after a 10-minute silent period. These findings establish the validity of sensorimotor adaptation paradigms to lead to increases in vowel contrast, an outcome that has the potential to enhance intelligibility.
Effects of high variability phonetic training on cue reweighting in non-native vowel perception by adult Chinese learners
Authors: Cheng Bing , Zhang Xiaojuan , Qin Dandan
Published: December 2020

While native English speakers have been found to primarily use vowel spectrum on /i/-/ɪ/ perception, Chinese learners of English dominantly use vowel duration. This study examined training effects on cue reweighting in perceiving /i/-/ɪ/ by Chinese learners. We modified the canonical HVPT paradigm with introducing variability along the secondary dimension for the contrast distinction (i.e., duration). Forty native Chinese-speaking adults were randomly assigned to two groups: the training group and the control group. Pre- and post- training tests used the tasks of natural word identification and synthetic phoneme identification. Synthesized phoneme stimuli were the two-dimensional (spectrum and duration) stimulus continua ranging from English /i/ to /ɪ/, and the natural word stimuli included both trained and untrained words produced by novel talkers. The results demonstrated that the training group showed more reliance on the primary spectral cue and less reliance on the secondary durational cue after training. The corroborating data from the word identification showed the training group improved significantly and generalized learning to new talkers and phonetic contexts. The control group did not show similar changes. These results indicated that high variability phonetic training is effective on helping L2 learners to retune attention to primary cues which facilitate generalization outcomes.
A theory of the piezoelectric slotted cylinder projector
Authors: Cochran John C. , Brown David A.
Published: December 2020

The energy method is used on the radial and circumferential displacement mode shapes of tapered piezoelectric slotted cylinder projectors to determine the electro-mechanical equivalent circuit parameters for the transducer. Results are determined for acoustically unloaded conditions for any degree of shell tapering. The resonance frequency (fr), mechanical quality factor (Qm), and electro-mechanical coupling factor (keff) are calculated and compared to measured data.
Acoustic features of infant-directed speech to infants with hearing loss
Authors: Lovcevic Irena , Kalashnikova Marina , Burnham Denis
Published: December 2020

This study investigated the effects of hearing loss and hearing experience on the acoustic features of infant-directed speech (IDS) to infants with hearing loss (HL) compared to controls with normal hearing (NH) matched by either chronological or hearing age (experiment 1) and across development in infants with hearing loss as well as the relation between IDS features and infants' developing lexical abilities (experiment 2). Both experiments included detailed acoustic analyses of mothers' productions of the three corner vowels /a, i, u/ and utterance-level pitch in IDS and in adult-directed speech. Experiment 1 demonstrated that IDS to infants with HL was acoustically more variable than IDS to hearing-age matched infants with NH. Experiment 2 yielded no changes in IDS features over development; however, the results did show a positive relationship between formant distances in mothers' speech and infants' concurrent receptive vocabulary size, as well as between vowel hyperarticulation and infants' expressive vocabulary. These findings suggest that despite infants' HL and thus diminished access to speech input, infants with HL are exposed to IDS with generally similar acoustic qualities as are infants with NH. However, some differences persist, indicating that infants with HL might receive less intelligible speech.
A seminal paper linking ocean acoustics and physical oceanography
Authors: Colosi John A. , Worcester Peter F.
Published: December 2020

The Reflections series takes a look back on historical articles from The Journal of the Acoustical Society of America that have had a significant impact on the science and practice of acoustics.
Jadwiga Folliot ou la diffusion d’une pratique semi-professionnelle dans le hand-ball français amateur de la fin des années 1970
Authors: Cardin Lise , Bolz Daphné , Saint-Martin Jean
Published: December 2020

« Quand je suis arrivée en France, […] tout ça, au fait, que j’avais vu, j’ai vécu en Pologne, j’ai transmis en France » (Folliot, 22 avril 2017). Cette notion de transmission semble importante pour Jadwiga Folliot, elle-même, lorsqu’elle décrit son parcours handballistique. Elle apparaît même comme un devoir au regard de sa trajectoire de vie. Née en 1953 à Cracovie, en Pologne, Jadwiga Nowak fait partie des meilleures juniors polonaises avant d’intégrer à 33 reprises, l’équipe nationale. Lorsqu’elle arrive en France le 1er décembre 1974, en pleine Guerre froide, des différences majeures transparaissent dans l’organisation du handball, et plus généralement dans la gouvernance du sport, entre la France et la Pologne. A partir de témoignages, de coupures de presse mais également d’archives institutionnelles de la Fédération Française de Handball, nous avons identifié les différents rôles assumés par Jadwiga Folliot dans le développement du handball au sein de l’Association Sportive de Mantes la Jolie, puis du département des Yvelines et plus largement au niveau de l’équipe de France qu’elle va intégrer en décembre 1975.Si elle ne peut importer le système sportif professionnel polonais en France, pays dans lequel le handball est encore amateur, il semble qu’elle ait réussi à importer certains aspects qui ont ensuite permis de hausser le niveau technique non seulement de son équipe de club, l’AS Mantaise, mais aussi et surtout de l’équipe de France féminine de handball.
Groundwater production from geothermal heating on early Mars and implication for early martian habitability
Authors: Ojha Lujendra , Buffo Jacob , Karunatillake Suniti , Siegler Matthew
Published: December 2020

Geothermal basal melting of thick ice sheets may solve the faint young Sun paradox on Mars.
Pattern blending enriches the diversity of animal colorations
Authors: Miyazawa Seita
Published: December 2020

Comprehensive analyses of fish colorations illuminate a simple mechanism creating intricate patterns on animals.
Spontaneous chemical functionalization via coordination of Au single atoms on monolayer MoS
2
Authors: Liu He , Grasseschi Daniel , Dodda Akhil , Fujisawa Kazunori , Olson David , Kahn Ethan , Zhang Fu , Zhang Tianyi , Lei Yu , Branco Ricardo Braga Nogueira , Elías Ana Laura , Silva Rodolfo Cruz , Yeh Yin-Ting , Maroneze Camila M. , Seixas Leandro , Hopkins Patrick , Das Saptarshi , de Matos Christiano J. S. , Terrones Mauricio
Published: December 2020

Single Au atoms on MoS
2
monolayers offer an effective way to control optical, electronic, and thermal properties of 2D materials.
BRAF inhibition protects against hearing loss in mice
Authors: Ingersoll Matthew A. , Malloy Emma A. , Caster Lauryn E. , Holland Eva M. , Xu Zhenhang , Zallocchi Marisa , Currier Duane , Liu Huizhan , He David Z.Z. , Min Jaeki , Chen Taosheng , Zuo Jian , Teitz Tal
Published: December 2020

Dabrafenib, an FDA-approved oral anticancer drug, prevents cisplatin- and noise-induced hearing loss in animal models.
Satellite-based estimates of decline and rebound in China’s CO
2
emissions during COVID-19 pandemic
Authors: Zheng Bo , Geng Guannan , Ciais Philippe , Davis Steven J. , Martin Randall V. , Meng Jun , Wu Nana , Chevallier Frederic , Broquet Gregoire , Boersma Folkert , van der A Ronald , Lin Jintai , Guan Dabo , Lei Yu , He Kebin , Zhang Qiang
Published: December 2020

Satellite reveals 10-day mean and spatially explicit variations in China’s CO
2
emissions during and after COVID-19 lockdown.
In Vitro
Susceptibility Testing of Omadacycline against Nontuberculous Mycobacteria
Authors: Brown-Elliott Barbara A. , Wallace Richard J.
Published: December 2020

Infections caused by nontuberculous mycobacteria (NTM) are increasing globally.
Mycobacterium avium
complex (MAC) and
Mycobacterium abscessus
complex are the most frequently encountered NTM, and oral treatment options are extremely limited for these pathogens, especially for the
M. abscessus
complex. In this study, the
in vitro
potency of omadacycline, a new tetracycline derivative, was tested against 111 isolates of NTM.
Assessing the Genetic Diversity of Austrian Corynebacterium diphtheriae Clinical Isolates, 2011 to 2019
Authors: Schaeffer Justine , Huhulescu Steliana , Stoeger Anna , Allerberger Franz , Ruppitsch Werner
Published: December 2020

Diphtheria is a vaccine-preventable disease with a high potential for reemergence. One of its causative agents is
Corynebacterium diphtheriae
, with some strains producing diphtheria toxin.