bluuebunny/crossref_metadata_2025 huggingface dataset:
Beatboxing: Teaching technical acoustical concepts through pop culture
Authors: Brown Alex C. , Shepherd Micah , Neilsen Tracianne B.
Published: July 2024

The motivation for this presentation is to demonstrate that vocal percussion, or “beatboxing,” can be a rich method of teaching and demonstrating various introductory acoustical concepts. Beatboxing can be an entertaining way to demonstrate the different acoustical sources of energy—namely burst, noise, and voice—and how they can be combined to create familiar and unfamiliar phonemes, such as the “PF” snare. It also provides an engaging way to introduce the anatomy of the vocal tract as the students can see and hear how vibrating different parts of the mouth and throat (e.g., vocal cords, epiglottis, vestibular folds, lips, etc.) alter the sound. Finally, beatboxing can be used to demonstrate the source-filter model of speech production through altering the sound source in the throat and displaying how to change your mouth shape to produce different formant-altering effects, such as the rapid formant shifting that gives a record scratch its characteristic sound. Beatboxing provides an entertaining and effective way to demonstrate technical concepts to students in an artistic format which captures the attention, especially of younger audiences. [Undergraduate research supported by the College of Physical and Mathematical Sciences, at Brigham Young University.]
An artistic approach is taken that uses principles in quantum mechanics to understand the signature sound created by granular synthesis in an undergraduate course on music synthesis techniques
Authors: Linz Jill A.
Published: July 2024

Music Synthesis Techniques is an advanced undergraduate course that explores how various methods are used to create and manipulate synthesized sounds used in sound design and audio production. Students explore their understanding through the creation of a series of short, one-minute compositions that utilize each technique. This paper focuses on that of granular synthesis. Granular synthesis is a music synthesis technique that is used to create unique and alluring sounds that has captivated modern music listeners. For audio engineers and sound designers, the term granular synthesis has always held an aura of mystery surrounding it. Recent developments in plug-ins for digital audio workstations allow them to easily create its signature sound, which have created a way to use granular synthesis as an art form. Unlike other methods, granular synthesis is rooted in the laws of quantum mechanics. The Heisenberg Uncertainty Principle is explored to understand how granular synthesis creates its signature sound, which in turn is then used to create artistic compositions through the manipulation of the variables. Several examples from student work as well as collaborative work will be included.
Fantastic acoustics: A magazine describing the importance and the scope of acoustics research in Québec
Authors: Robin Olivier , Krpic Tamara , Carrion Alexis , Proulx François , Demuynck Michel , Gallerand Lucie , Fraisse Valérian , Trudeau Christopher , Tarlao Cynthia , Perrier de la Bathie Cécile , Bernier-Breton Coralie , Dupont Thomas , Doutres Olivier , Voix Jeremie , Cauchy Pierre , St-Onge Guillaume , Guastavino Catherine
Published: July 2024

It's often difficult for the general public and young people to grasp the importance of acoustics in everyday life and its many branches and fields of application. However, it's equally complex for people working or studying acoustics to communicate to this audience while avoiding the same focus on detail as scientific publications. Science communication skills are seldom taught, and multi-disciplinary approaches are little used. This paper describes the work carried out as part of the ‘Fantastique acoustique—Fantastics acoustics' project, which aims to raise awareness of the acoustics-related research at four Québec universities and train students in science communication. Eight student teams were partnered with cartoonists to produce 3-page comic strips and an associated corpus (including references and videos). The steps involved in producing the magazine are described, as are some of the final works. In particular, a survey including the students and the artists identifies the main positive points and the most significant challenges of such a partnership.
Spectral analysis of the air flow pattern near the labium of a recorder
Authors: Giordano Nicholas
Published: July 2024

Navier-Stokes-based simulations of the air flow through a recorder allow detailed tests of analytic theories of how the pattern of flow—specifically the creation and time evolution of vorticity near the labium—gives rise to the sound of the instrument. A new spectral analysis algorithm has been developed to extract the flow pattern at the fundamental frequency for a soprano recorder playing a steady tone. This analysis allows the flow pattern at the fundamental frequency to be separated from the flow patterns at other frequencies and from the uniform flow pattern, i.e., the time independent flow associated with the air jet emerging from the flue. This gives an especially clear elucidation of the time dependent process in which vortices are created and evolve during the course of a musical tone. This analysis technique can also be used to extract the flow patterns at the frequency of the second partial and at the frequency of the recently discovered half harmonic [1], which show a geometrical structure that is distinctly different from that found at the fundamental frequency. Our spectral analysis technique should allow more detailed tests of the theory of vortex produced sound for a flue instrument than have been possible to date. N. Giordano and K. L. Saenger, J. Acoust. Soc. Amer. 154, 2917 (2023). [Work supported by NSF under Grant No. PHY2306035.]
How can acoustic measurements help us understand severe weather phenomena such as lightning?
Authors: Farges Thomas , Coulouvrat François , Bestard Damien
Published: July 2024

Lightning is an indicator for monitoring severe weather events like heavy precipitation, flash floods, hail… It is also a climate variable for monitoring global warming. Lightning emits light, sound and radioelectromagnetic fields, allowing remote detection and analysis. Acoustic measurements can be used to, for instance, track global warming over more than 70 years via the keraunic level (the number of thunderstorm days per year in a specific location), or detect and monitor severe weather events such as cyclones, e.g. the Medicanes, or characterize optical phenomena such as sprites associated with violent thunderstorms, or highlight temporal changes in the upper layers of the atmosphere, such as the semi-annual oscillation of stratospheric winds in tropical zones. At closer ranges, less than 30 km, acoustic network measurements complement electromagnetic observations to reconstruct the 3D structure of cloud-to-ground and intra-cloud discharges. Recently, it has been shown possible to provide the 3D structure of acoustic power within the lightning source. From flash to flash, this power shows four orders of magnitude variations, similarly to electromagnetism or optics. Moreover, it outlines that large variations of power also exist even within a lightning flash, reflecting heterogeneities in conductivity within the discharge.
Measurements of nonlinear electric-acoustic interactions in lead zirconium titanate
Authors: Lirette Robert , Karpisz Tomasz , Musiał Małgorzata , Petculescu Gabriela , Hagerstrom Aaron , Orloff Nathan , Stelson Angela C.
Published: July 2024

When electric and acoustic waves simultaneously pass through a piezoelectric material, nonlinearities can arise. The electric and acoustic waves can mix, generating a signal consisting of both sum and difference spectral components. Here we present a method of directly measuring the nonlinearly mixed electric-acoustic signal using a vector network analyzer (VNA). In normal VNA operation, sources and receivers operate at the same frequency. In our measurements, we employ a frequency offset mode, where receivers in the VNA can be tuned to a frequency different from the source frequency. Here, we measure at the expected mixing product frequency of the electrical and acoustic signals we introduce into the measurement to capture nonlinear electric-acoustic mixing. We present measurements of electric-acoustic mixing in a block of lead zirconium titanate (PZT) mounted on top of an electric co-planar waveguide connected to the VNA. The results show the presence of many coupled electric-acoustic modes. To interpret these modes, we characterized the PZT block with modal analysis and finite element simulations. Some of the observed nonlinear electric-acoustic modes directly correlated with the mechanical modes of the block, while others did not. Overall, this method allows for direct probing of non-linear electric-acoustic mixing in materials and devices.
Effects of auditory processing ability on the phonological and acoustic processing of Mandarin tone by Thai speakers: An ERP study
Authors: Zou Yu , Cheng Bing , Zhang Yang
Published: July 2024

This study investigated how Mandarin-naïve Thai speakers’ auditory processing ability affects their phonological and acoustic processing of Mandarin tone. The participants were 20 native Mandarin speakers and 19 Mandarin-naïve Thai speakers. A 10-step computer synthesized Tone 1 (T1)–Tone 2 (T2) continuum was manipulated for identification task. The stimulus 1, 3, 5, 7, 9 from the T1–T2 continuum were used in a multi-feature passive oddball ERP paradigm, encompassing within-category and across-category stimuli with equivalent large-scale and small-scale acoustic intervals. We used pitch discrimination, melody reproduction, and rhythm reproduction to assess participants’ auditory processing ability. The identification results showed that Mandarin-naïve Thai speakers’ exhibit a weaker categorical perception (CP) of Mandarin tones compared to the native Mandarin speakers, a pattern consistent with ERP results observed at both sensor and source levels. Further analysis revealed higher auditory processing ability leads to enhanced CP of Mandarin tone for learners from Thai, and the same improvement is observed in the melody memory for acoustic processing of Mandarin tone. These findings add to our understanding on how individual differences influence phonological and acoustic processing of Mandarin tone during the initial stage of second speech learning.
Uncertainty quantification for acoustical problems
Authors: Gerstoft Peter , Khurjekar Ishan D.
Published: July 2024

Acoustical parameter estimation is a routine task in many domains and is typically done using signal processing methods. The performance of existing estimation methods is affected due to external uncertainty and yet the methods provide no measure of confidence in the outputs. Hence it is crucial to quantify uncertainty in the estimates before real-world deployment. Conformal prediction is a simple method to obtain statistically valid prediction intervals from an estimation model. In this work, conformal prediction is used for obtaining statistically valid uncertainty intervals for various acoustical parameter estimation tasks. We consider the tasks of DOA estimation and localization of one or more sources in an acoustical environment. The performance is validated on plane wave data with different sources of uncertainty including ambient noise, interference, and sensor location uncertainty, using statistical metrics. Results demonstrate that conformal prediction is a suitable and easy-to-use technique to generate statistically valid uncertainty quantification for acoustical estimation tasks.
Design considerations for mass timber in commercial buildings
Authors: Manley David
Published: July 2024

Mass timber commercial buildings can significantly shift the building and design industry to a more sustainable path, but integrating architectural, engineering, and acoustic systems within this relatively new superstructure presents many challenges for designers. This talk will discuss DLR Group’s integrated design approach and mass timber research including architectural design, structures, and acoustics.
Of bats and robots
Authors: Müller Rolf , Westcott Ben , Nnoka Chi
Published: July 2024

Some bat species feature joint adaptations to their biosonar sensing and flight systems that allow them to navigate and hunt in dense vegetation. Understanding how biosonar sensing and flight are connected in these species poses a challenge: Kinematics recordings of bat-flight can document the system outputs, but due to various limitations, especially on processing, analysis of bat flight has been limited to minimal numbers of flights and hence has had difficulty to capture the natural variability in flight maneuvers. On the input side of the bats' flight-control system, it is necessary to understand the stimulus ensemble that guides flight in dense vegetation. Navigation in these cases must be based on clutter echoes, i.e., signals consisting of many unresolved components. Since the biosonar inputs into a bat are difficult to record without heavy interference with the animals' behaviors. Hence, biomimetic sonar robots can be used to collect stimuli from natural environments and their recreations. With their superior abilities to find patterns, deep-learning offer an opportunity to cut through the complexity of the input and output data of bat flight control and elucidate how clutter echoes are interfaced with the high-dimensional flight kinematics of bats to create the animals' exceptional maneuvering capabilities.
The acoustic trap theory and its application to lung ultrasound
Authors: Demi Libertario
Published: July 2024

In this lecture, the acoustic trap theory, as first introduced in 2016 in the context of lung ultrasound (DOI: 10.7863/ultra.15.08023), will be illustrated. Recent publications focusing on the design and validation of lung mimicking phantoms (DOI: 10.1038/s41598-017-13078-9, 10.1121/10.0001797, 10.1121/10.0007482) will be reviewed in the light of this theory. Moreover, its relevance to the monitoring and diagnosis of lung diseases by means of quantitative lung ultrasound spectroscopy will be discussed. To this end, results obtained within published (DOI: 10.1109/TUFFC.2020.3012289, 10.1121/10.0001723) and ongoing multicenter clinical studies, performed with dedicated multi-frequency imaging modalities implemented on open research scanners, will be presented and looked at through the lens of this theory.
Predicting the spontaneous vaporisation of superheated perfluorocarbon droplets
Authors: Bau Luca , WU QIANG , Ovenden Nicholas , Stride Eleanor P.
Published: July 2024

Superheated perfluorocarbon droplets have been widely explored as agents for ultrasound imaging and therapy, as well as for other applications such as radiation dosimetry. Submicrometre, or “nano” droplets offer a number of potential advantages over microbubbles, e.g., longer circulation half-lives, higher surface area-to-volume ratio and the ability to perfuse the microvasculature more easily. A key challenge in the use of nanodroplets, however, is the need to avoid spontaneous vaporisation whilst keeping the energy required for acoustic activation within the range of pressures that can be used safely in humans. This is especially important for imaging applications. Perfluoropropane (C;3F;8) microbubbles can be condensed to form liquid nanodroplets that offer a good trade-off between thermal stability and acoustic vaporisation threshold. Anecdotal reports, however, suggest that C;3F;8 droplets can spontaneously vaporise, and may therefore pose a potential safety risk, especially if bubble coalescence occurs. The aim of this study was to build on recent theoretical models of droplet vaporisation and investigate the probability of vaporisation as a function of temperature and interfacial tension. The results are compared with experimental measurements of vaporisation rates for different droplet formulations.
Microcavitation dynamics of vaporized perfluorocarbon nanodroplets captured with an acoustical camera
Authors: Burgess Mark , Ketterling Jeffrey A.
Published: July 2024

Perfluorocarbon nanodroplets are on-demand cavitation nuclei for numerous biomedical applications. These nanodroplets remain in a metastable state until an ultrasound pulse of sufficient negative pressure initiates conversion from a liquid droplet into a gaseous micro- or nano-bubble in a process termed acoustic droplet vaporization (ADV). Extensive research has gone into understanding their interaction with ultrasound at varying acoustic and ambient conditions. Recent studies have detected intra- and post-excitation collapse emissions indicative of inertial cavitation. This study aims to further understand the post-ADV dynamics of perfluorocarbon nanodroplets with an acoustical camera technique. Nanodroplets were activated with a low-frequency ultrasound pulse (5 MHz) while being insonified with a high-frequency (35 MHz) probing wave. The side scattered emissions from the probing wave were captured with another matched high-frequency transducer. The amplitude modulation of these emissions is proportional to the radial strain; thus, a relative radius-time curve can be extracted from the scattered signal after filtering and enveloping. Results show that this technique can capture the radial growth and collapse curves of these newly formed bubbles and aligns well with intra- and post-excitation emissions indicative of inertial cavitation. This approach could be useful to understand post-ADV dynamics of various droplet formulations.
Acoustics at UMass Dartmouth
Authors: Brown David A. , Buck John R. , Gendron Paul J.
Published: July 2024

The University of Massachusetts Dartmouth has a long history spanning 5 decades of graduate courses offerings and research in underwater acoustics, transduction and signal processing leading to M.S. and Ph.D. degrees in Electrical Engineering. Collaborations between Marine Science, Physics, Mechanical, Bioengineering, and Electrical Engineering departments offer many interdisciplinary opportunities in Acoustics. Courses include Fundamentals of Acoustics, Vibrations, Underwater Acoustics, Electroacoustic Transducers, Medical Ultrasonics, Sonar, Digital Signal Processing, Array Processing, Random Signals, Information Theory, Communications, Detection and Estimation. Many unique facilities including an Underwater Acoustic Test Tank, Open-Ocean water access, and Unmanned Underwater Vehicles support both undergraduate and graduate projects. Research focuses include transducers and transduction science, materials characterization, calibration, array and sonar signal processing, animal bioacoustics, communications, detection and estimation, active and passive sonar funded by Office of Naval Research and Industry.
Investigating sonic booms using impulse metrics
Authors: Sorrell Avery K. , Anderson Mark C. , Nyborg Kaylee , Gee Kent L.
Published: July 2024

As an impulsive sound, a sonic boom exhibits traits similar to other transient acoustic impulses, such as a single strike of a sledgehammer strike or an exploding firework. Although several metrics exist to assess the nature and potential acoustic hazards of these other impulsive sounds, these metrics are rarely applied to sonic booms. This paper investigates the use of several metrics commonly applied to impulsive sounds, such as B and D durations or the kurtosis of the pressure waveform, for sonic booms recorded during previous NASA flight test campaigns, including CarpetDIEM (Carpet Determination in Entirety Measurements) and QSF18 (Quiet Supersonic Flights 2018). Understanding the behavior of these metrics in urban (QSF18) and rural (CarpetDIEM) environments adds to the larger body of knowledge concerning sonic boom measurements and properties and may be useful in quantifying sonic boom variability in communities.
Assessment of noise complaints as an indicator of long-term effects of aircraft noise on communities surrounding aerodromes
Authors: Novak Colin , Jovanovic Julia
Published: July 2024

Aircraft noise is considered by many as the most burdensome part of aircraft operations. Communities neighbouring airports often express concerns about the possible health effects of chronic exposure to noise. To quantify the long-term effects of environmental noise exposure, researchers often use the metric of annoyance. Annoyance is widely considered to be the most well-corroborated health effect of aircraft noise and a moderating factor for other suspected health effects. Annoyance can also be correlated to average cumulative noise levels, such that higher levels of chronic noise likely evoke higher levels of annoyance within the population. Annoyance data is typically collected using extensive surveys and/or interviews, which are costly and time-consuming. In the absence of annoyance data, complaints are often used as a proxy for annoyance. This research used complaint, noise and annoyance data to demonstrate that complaints do not equate to annoyance, nor do they correlate to cumulative noise metrics. Thus, while complaint data may prove useful in analyzing short-term response to operations, it should not be relied upon for the assessment of long-term impacts from aircraft noise exposure, nor should it be used to direct noise and annoyance mitigation initiatives.
On the sensitivity and noise of acousto-optic sensing: Exploring the detection limits
Authors: Ishikawa Kenji
Published: July 2024

Acousto-optic sensing has garnered increasing attention in recent years due to its non-contact nature, gaining importance in a range of acoustic measurement applications. Although its potential is widely recognized, the signal-to-noise ratio often requires enhancement in practical applications, which can impede further development. While more sensitive measurement methods have been evolving, the discussion around noise and detection limits in acousto-optic sensing remains limited. This presentation will highlight the author's recent findings on sensitivity and noise in acousto-optic sensing. It aims to illuminate the achievable detection limits through a detailed analysis of optical and acoustic noises. The insights provided will offer a deeper understanding of the complexities involved and potentially guide future advancements in this field.
Sensing viscous acoustic flow: Using spider silk to hear
Authors: Zhou Jian , Lai Junpeng , Miles Ronald
Published: July 2024

Measurements obtained with a laser vibrometer show that a single strand of spider silk captures sound with almost full fidelity across a broad frequency range from infrasound to ultrasound, surpassing the performance of any known microphone or ear. The high responsivity of the silk to acoustic particle velocity enables the orb-weaving spider to hear sounds from meters away by utilizing its web—a hearing mechanism distinct from that of other animals that rely on an organ within their body. Laser-based measurements have also revealed that small creatures like mosquitoes can hear far-field sounds, similar to the spider, by sensing acoustic particle velocity rather than pressure. These findings offer insights for designing novel acoustic flow detectors and have led to the development of a recently commercialized flow microphone.
Spectral resolution and voice cue weighting in adults with normal hearing
Authors: Sevich Victoria A. , Tamati Terrin N.
Published: July 2024

Cochlear implant (CI) users use acoustic voice cues differently than normal hearing (NH) adults to identify a talker’s gender. Specifically, whereas NH listeners weight a talker’s fundamental frequency (f0) and resonance (operationalized as vocal tract length or VTL) equally, CI users rely almost exclusively on f0. CI users’ abnormal cue weighting may partially arise due to degraded auditory information delivered by the CI. We hypothesized that altering the amount of spectral information in the signal impacts voice cue weighting in NH listeners. Thirty NH adults performed a gender identification task. Auditory stimuli were monosyllabic words synthesized to have one of five f0 values and one of five VTL values. Synthesized voices were processed using a 16-, 8-, and 4-channel noise-band vocoder. Perceptual weights for each voice cue were estimated as the coefficients for f0 and VTL in regression models, with higher coefficients corresponding to stronger perceptual weightings. Listeners relied more on f0 in conditions with less spectral resolution than in conditions with greater spectral resolution. Cue weights for VTL did not change across conditions. Results suggest that removing frequency information from the auditory signal can modify the extent to which listeners use f0 to identify the gender of a talker.
Acoustic divergence from the training sample determines talker identification accuracy for emotional voices
Authors: Shen Lue , Wang Yuxuan , Wong Patrick , Perrachione Tyler K.
Published: July 2024

Different emotional states introduce substantial acoustic variations in talkers’ voices. It remains unclear how within-talker variability across emotional states affects listeners' ability to maintain perceptual constancy during talker identification. Here, we investigated (1) how changes in talkers’ emotional state affected talker identification accuracy, (2) how emotional state affected key features of voice acoustics, and (3) how emotion-related changes in these acoustic features affected listeners’ talker identification performance. Forty-eight listeners learned to identify talkers from speech expressing one emotional state (neutral, fearful, or angry) and then attempted to generalize that knowledge to speech expressing another emotional state. Talker identification accuracy was significantly worse in untrained emotions. Changes in voice acoustics across emotions were characterized for mean F0, F0 variability, jitter, HNR, speaking rate, and mean F2. To determine how emotion-related acoustic changes affected talker identification, we modeled talker identification accuracy as a function of difference in these features between training and test stimuli. Accuracy decreased as acoustic differences increased, regardless of talkers’ emotion. Thus, perceptual constancy depends on acoustic similarity to prior experience with a talker’s voice. Larger acoustic deviations, like those introduced by changes in emotional state, are more likely to cause a listener to misidentify a talker.
Ultrasonic characterization of material anisotropy in additively manufactured AlSi10Mg
Authors: Turner Joseph A. , Matz Nathanial , Brandl W. T. , Kumar Pulkit , Roberts Ronald A. , Collins Peter C.
Published: July 2024

Metal additive manufacturing (AM) based on laser powder bed fusion (LPBF) generates components by melting metal powder on a layer-by-layer basis. The melting and cooling process often generates samples with a preferred material symmetry aligned with the build direction. This anisotropy affects mechanical performance and can be challenging to characterize nondestructively. Here, LPBF was used to create samples of AlSi10Mg with specific geometries to affect the overall anisotropy. In addition, the hybrid AM process of interlayer milling was used to impact the microstructure and residual stress of some samples. Ultrasonic measurements were used to characterize the samples using both coherent wave and diffuse wave experiments to capture the anisotropic nature of the wave speed and scattering. The material symmetry and morphology of the grains affect the wave speed, attenuation, and backscatter with respect to direction. Furthermore, spatially resolved acoustic spectroscopy was used to provide insight regarding the localized wave speeds with respect to sample location and propagation direction. The experimental data were used collectively to quantify differences between the AM processes used to create the samples. Such information can be used to guide AM process parameters to optimize sample performance. Finally, prospects for characterization of residual stresses will be discussed.
Beyond visual primes: Audiovisual integration of racial identity and sentence intelligibility
Authors: Nickel Eleanor , Tripp Alayo , Schutt Enengy , Munson Benjamin
Published: July 2024

There is no biological basis for racial categories. Yet, the presentation of racialized stimuli impacts psycholinguistic processing, suggesting that a talker’s racial identity affects measures of intelligibility (Babel & Russell, 2015; McGowan, 2015). Previous work has used static visual primes, presenting images accompanied by acoustic sentence stimuli. Static visual primes may prime expectations of the person’s speech, with unexpected pairings decreasing intelligibility. These findings show that social expectations affect speech intelligibility and have broad implications for real-world speech perception in high-stakes educational (Evans, Munson, & Edwards, 2017), social (Purnell, Baugh, & Idsardi, 1999), and legal (Rickford & King, 2016) contexts. Expanding our understanding of the psycholinguistic and psychophysical mechanisms behind these phenomena requires experimentation with dynamic, audiovisual speech rather than static visuals. The current experiment presents conflicting visual and auditory cues indexing the white and Black racial identities of the talkers. The talker who is seen (the ‘visual’ talker) and the racial identity of the talker who is heard (the ‘audio’ talker) are fully crossed. This design allows us to examine how intelligibility is influenced by visual racial identity, audio racial identity, and the audiovisual (mis)match between them. Data collection is currently in progress and includes groups of both white and Black listeners.
Using computational models to study accent adaptation: A tutorial
Authors: Moore Leo , Chiu Samantha , Kutlu Ethan
Published: July 2024

One of the limitations in accent perception research is the difficulty of quantifying how much exposure is needed to observe adaptation to a novel accent. While numerous studies have investigated this issue (Baese-Berk et al., 2013; Clarke & Garrett, 2004), it has been impossible to control for individual-level differences and solely focus on linguistic differences with human participants. However, computational models can be intentionally set in terms of these features to better understand the process of adaptation to novel accents. Here we discuss how machine learning models can be implemented using PyTorch, a framework in Python made by Meta. PyTorch allows for the easy creation of language learning models that can be used in speech-recognition experiments (Paszke et al., 2019). Here we use the Wav2Vec2 model created by Meta, pre-trained on 960 hours of the Librispeech ASR corpus (Panayotov et al., 2015). We discuss importing the model and fine-tuning it using samples of different accents. Next, we demonstrate building a decoder using a greedy algorithm to transform the model's classification into a transcript. Our goal is to compare simulations against data from human participants and tease apart the direct effects of individual variability on accent perception.
Assessing retroflex and alveolar liquid perception and production in heritage Tamil speakers
Authors: Muthukumarasamy Kamala , Narayan Chandan
Published: July 2024

In this presentation, we explore factors affecting and the relationship between perception and production of the alveolar-retroflex liquid contrast ([l]-[É­]) in heritage Tamil speakers. In particular, we examine the connection between language and identity in the maintenance of this acoustically fragile contrast with similar spectral characteristics, shown through low perceptual salience. Tamil speakers (n = 18) completed an AX discrimination task with non-word Tamil VCVs was administered. D-prime, a bias free measure of perceptual distance, was computed from the discrimination data. Additionally, participants provided minimal pairs with the target consonants in an elicited production task. An F3-F2 (Hz) score was taken as a measure of productive salience, with alveolars having a larger difference than retroflexes. Quantitative results showed a high degree of variation in productive salience, as some speakers clearly produce the contrast while others did not. Perceptual distance was also variable, with some participants clearly showing categorical discrimination while others did not. Qualitative results revealed that a concrete ties to tangible culture and a strong linguistic identity can serve as an indicator of accuracy in perception and production. This research addresses whether acoustically fragile contrasts are realized in heritage Tamil and provides new insight into heritage phonological contrast retention and maintenance.
Application of deep learning methods for obstacle classification in ultrasonic surround sensing
Authors: Eisele Jona , Gerlach André , Maeder Marcus , Koch Andreas , Marburg Steffen
Published: July 2024

Ultrasonic sensors are widely used in driver assist systems for close-range surround sensing. Based on the pulse-echo method, the distance to obstacles is calculated, particularly in scenarios such as parking and maneuvering. For advanced ultrasonic perception systems, however, the classification of obstacles should be considered, too. For instance, it is relevant to distinguish between traversable and non-traversable objects, as well as to detect pedestrians. Classifying obstacles by ultrasonic echoes remains an area of ongoing research, and, in contrast to ultrasonic ranging, implementation in current systems is rudimentary at best. This work examines the application of deep learning methods for ultrasonic-based object classification in driver assist systems. Features based on raw time signals, amplitude- and phase-based echo features as well as time-frequency images are compared. The preprocessing and feature extraction methods are evaluated based on experimental data captured in low and high clutter environments. Promising classification results are achieved using convolutional neural networks, demonstrating a significant improvement over traditional methods. Finally, we discuss the benefits of employing small aperture ultrasonic sensor arrays to increase classification robustness using beamforming methods.
Direction of arrival estimation with convolutional neural networks and multiple signal classification
Authors: Bell Christopher J. , Adhikari Kaushallya , Freeman Lauren
Published: July 2024

Recently, there has been a proliferation of applied machine learning (ML) research, including the use of convolutional neural networks (CNNs) for direction of arrival (DoA) estimation. With the large increase of research in this area, it is important to balance the performance and computational costs of CNNs with classical methods of DoA estimation such as Multiple Signal Classification (MUSIC). We outline the performance of both methods of DoA estimation for single source and two source cases and compare them to the Cramer-Rao lower bound (CRLB). For each source case, a CNN was trained for a perfect uniform line array (ULA), a perturbed ULA, and a ULA with missing sensors. The three cases are interesting studies as classical methods for DoA estimation such as MUSIC assume perfect array conditions, whereas the CNNs assume nothing about the structure of the data. The training data for each network was created by leveraging a signal model to create synthetic data at different SNRs. The results for each network are then compared to the results for MUSIC using the same signal case and array condition. The results indicate that for the single source case the CNN only performs significantly better than MUSIC for the perturbed array case. For the two-source case, the CNNs significantly outperform MUSIC for all ULA conditions, however, when compared to the CRLB it is shown that the CNN typically produces a biased estimate.
Using deep learning for recreating binaural audio
Authors: Sloan Will , Laghai Amir
Published: July 2024

In recent years, there has been an increase in research around generating spatialized audio using a mono audio signal. Methods like using neural networks which combine image segmentation with object location for adding back the spatial qualities are often developed. Instead, our project focuses on taking arbitrary mono input sound and an input angle, and outputting spatial stereo audio of the input sound with the directionality of the angle. This is different from current implementations as it is a simpler approach to what spatial audio generation is, and it allows for the use in the model in new areas. Using a binaural microphone and a custom-made anechoic chamber, 120 hours of labelled binaural audio was recorded for use in our model. The audio consists of frequency sweeps, pink noise, and phonetically balanced speech. Our method is to predict a complex short-time Fourier transform mask which will contain the phase and amplitude within it. The model is an autoencoder based on the U-NET model, which is applied to the mono input before being compared to the labelled data for training. With this simpler approach, we hope to make spatial audio more accessible for a variety of applications.
Case study of noise intrusion into glass facade residential building
Authors: Hougland Dana S.
Published: July 2024

A combined residential and hotel building with a glass facade adjacent to a major transportation corridor provided challanges for the owner and designers in selecting an appropriate quantitative metric for evaluating the subjectively acceptable level of noise intrusion. Surveys at a series of buildings with similar proximities were evaluated to compare subjective impressions to quantitative projections.
Residential outdoor-to-indoor acoustic conditions: Method and pilot data
Authors: Cunha Iara B. , Veitch Jennifer A. , Nixon Ashley , Mueller-Trapet Markus , Skoda Sabrina , Mahn Jeffrey
Published: July 2024

Health and well-being of people is directly influenced by the indoor environmental quality of the buildings they occupy. Noise exposure, for example, is not only a cause of annoyance but it is established as a risk factor for the development of cardiovascular diseases and it is a cause of sleep disturbance. As part of a broader research project focused on establishing guidance for suitable interior conditions for adults as they age, the National Research Council of Canada is developing a field study to measure, among other environmental conditions, outdoor-to-indoor noise conditions at homes. Objective parameters such as sound pressure levels will be monitored for a period of time and compared to residents’ health and well-being assessments through sensors and surveys. The methodology and instrumentation used for the acoustic measurements will be presented as well as the early results from pilot tests. The future outcomes of this study will contribute to guidance for both new-build and retrofit scenarios of dwellings for aging in place.
Heterogeneous ultrasonic wave properties in leg cortical bones of Thoroughbreds
Authors: Kodama Shuta , Tsubata Taisei , Tamura Norihisa , Mita Hiroshi , Chiba Ko , Matsukawa Mami
Published: July 2024

Safe and inexpensive diagnosis of leg bone disease in the field is very important for Thoroughbreds and large animals, because large animals are difficult to transport, and prompt diagnosis is required. The quantitative ultrasound (QUS) is attracting attention for the evaluation of leg bones because it can give us information of elasticity, which is related to the bone quality. For the development of a QUS system of animal leg bones, understanding of characteristic ultrasonic wave properties (velocity and attenuation) is a key issue. Therefore, wave properties in Thoroughbreds’ leg bones were obtained experimentally using an ultrasonic pulse technique. Precise measurements showed clear heterogeneity of ultrasonic wave properties due to the location. Opposed to the other large animals like bovines, high wave velocities were found in the medial and lateral parts, which possibly tells the effects of hard training in the fields. From a clinical perspective, the medial and lateral parts are less prone to diseases such as periostitis. The attenuation was greater in the posterior part, especially in the porous area near the trabecular bone. We also found that attenuation depended on bone matrix. Further investigation is necessary to discuss on the heterogeneity of wave properties in detail.
Automotive tire facility noise characteristics
Authors: VanDelden Peter , Carboni Lorenzo , Grozev Slavi
Published: July 2024

The environmental noise influence of facilities that change, replace or repair tires has notable acoustic characteristics, including the sound from air impact wrenches. Air impact wrenches are a ubiquitous tool at such facilities, where they are used to remove and replace the nuts that hold wheels on cars and trucks. The sound is commonly emitted through open doorways. Tire facility sound data was evaluated for impulsive characteristics using procedures described in the newest version of ISO 1996-3. The dynamic nature of air impact wrench sound also allowed the ISO 1996-3 approach to be evaluated.
Relationship between intra-community noise tolerance distributions and fitted dose-response funtions
Authors: Horonjeff Richard D.
Published: July 2024

Increasingly, researchers are employing fitted exposure-response functions to not only characterize the relationship between sound level and prevalence of annoyance but also to compare the relative noise tolerance of individual communities. The sound level at which 50% of the population is annoyed has been advanced as a community noise tolerance metric. This paper combines prior research and recent simulations to reframe the discussion in terms of plausible distributions of individual (personal) noise tolerances within a given community; the integrals of those (density) distributions become the (cumulative) observed exposure-response relationships. Various tolerance distributions are developed, their resulting cumulative exposure-response relationships calculated, and the ability of commonly-employed functional forms to represent those cumulative relationships presented. The results of the current investigation strongly suggest that data sets which include annoyance fractions of 50% have the greatest chance of accurately predicting the 50%-annoyed sound level. The further the data set lies from the 50%-annoyed point the more dependent an extrapolated estimation becomes on the fitted functional form accurately representing the true cumulative relationship. Errors of estimation are shown for a number of tolerance distributions, functional forms and experimental data ranges. Finally, some remedial recommendations are offered.
Neurophysiological biomarkers of speech-in-competition performance under different conditions of attentional load
Authors: Correa-Medina Erick , Solís-Vivanco Rodolfo , Koerner Tess , Gallun Frederick J. , Seitz Aaron , Lelo de Larrea-Mancera Sebastian
Published: July 2024

A body of research has identified a complex integration of perceptual and cognitive processes that can modulate comprehension of speech-in-competition (SIC). However, it is not well understood how the neurophysiological correlates associated with SIC performance vary under different conditions of attentional load. Here, we analyzed the neurophysiological correlates of a SIC task using variations in masker type (spatialization, gender, language), target-to-masker ratios (TMRs), and presence of a simultaneous working memory (WM) task to manipulate attentional load during SIC performance. We used a counter-balanced block design to record EEG in each condition in 15 undergraduate young adults without hearing difficulties. SIC was assessed using the spatial release from masking task in the PART digital application. Behavioral results indicated significant differences in accuracy depending on TMR across types of maskers. We did not observe behavioral differences in SIC performance associated with the inclusion of a parallel WM task. Quantitative EEG showed a series of potential EEG biomarkers that can complement behavioral measurement in discriminating different attentional load conditions of SIC performance. These post hoc observations are discussed in relation to the extant literature and will be further investigated in future work.
Profile analysis in the inferior colliculus: physiology and modeling studies
Authors: Agarwalla Swapna , Guest Daniel R. , Carney Laurel H.
Published: July 2024

Profile-analysis is a strategy for assessing sensitivity to differences in spectral shape [Green, Oxford University Press, 1988]. Despite extensive behavioral data, the neuronal mechanisms underlying profile-analysis remain elusive. To bridge this gap, extracellular recordings were made in awake rabbit inferior colliculus (IC) and simulated using a computation model. The standard stimulus was a log-spaced, n-component, zero-phase, equal-amplitude complex tone, presented diotically. The central component was incremented in the target stimulus. The discharge rate as a function of characteristic frequency (CF) was inferred by shifting the stimulus spectrum past the CF of each neuron. When the increment frequency was near CF, IC neurons had rates that decreased as the increment increased, contradicting a simple energy-based code. In some cases, the differences between rates for target and standard were largest for stimuli with component spacing that yielded the lowest thresholds in listeners. Responses of IC neurons that were excited by amplitude-modulated stimuli were consistent with model predictions for profile-analysis stimuli [Maxwell et al., JASA 147, 3523 (2020), Guest et al., bioRxiv (2023)]; however, the models did not explain responses of other types of IC neurons. Potential factors contributing to this discrepancy, such as off-CF inhibition and chirp selectivity, will be further explored. Support: NIHR01-DC010813
Real-time, sample-by-sample estimation of multiple signal waveforms from acoustic array data using B-splines
Authors: Frazier Garth
Published: July 2024

This work presents a real-time signal processing algorithm that estimates time-domain waveforms of multiple plane wave signals on a sample-by-sample basis from data measured by an acoustic array. Moreover, the algorithm provides sample-by-sample estimates of the direction-of-arrival (DOA) of the waveforms. In this case sample-by-sample means that as each sample of data is measured by the array estimates of the waveforms and their directions-of-arrival are updated. While the basic idea can be based on almost any finite-dimensional approximation to a function space, this algorithm makes use of B-spline basis for the signal waveforms. Other features of the approach include no restrictions on signal waveform shape, automatic estimation of the number of signals present, automatic step-size adjustment for correction of signal waveform and direction-of-arrival parameters to achieve good performance while guaranteeing stability, and the use of circular (spherical) statistical models for 2-D (3-D) DOA estimates. The approach contrasts with blind source separation (BSS) methods that are based on non-Gaussian statistical assumptions and that do not assume a known array geometry nor a propagation model. This method is closely related to algorithms based on block-of-data by block-of-data processing but does not require stitching results from block processing to create time-domain waveform estimates.