bluuebunny/crossref_metadata_2025 huggingface dataset:
Applying intuition to Fourier analysis by rendering images with vibration
Authors: DiPassio Tre
Published: July 2024

It has been said that “Everything in life is vibration.” While this may seem dramatic, it is true that we can describe any shape as a superposition of a structure’s bending modes using Fourier decomposition. In this session, I present an assignment that involves the rendering of images and artwork using only a subset of a rectangular membrane’s mode shapes. This assignment allows students to engage with fundamental concepts such as Fourier analysis and the modal nature of structural vibrations in a way that allows them to see and interact with the results of their work. A natural extension is to simulate the response of a plate to an external stimulus using the Fourier series, and to verify the results of their simulation experimentally using tools such as laser vibrometry. While exciting complex patterns in the vibrational response of a real plate is difficult in practice, this assignment provides a memorable and engaging baseline for understanding the modal composition of induced structural vibrations.
Perceptual consequences of reverberant environments on spatial unmasking
Authors: Weeldreyer Gabriel S. , Wang Lily M. , Peng Z. Ellen
Published: July 2024

Spatial hearing provides access to auditory spatial cues that promote speech perception in noisy listening situations. However, reverberation degrades auditory spatial cues and limits listeners’ ability to utilize these cues for segregating target speech from competing babble. Hence, spatial unmasking—an intelligibility benefit from a spatial separation between a target and masker—is reduced in reverberant environments as compared to free field. To understand the perceptual consequences of poorer spatial unmasking in reverberation, we assessed three aspects of functional spatial hearing in virtual reverberant environments: perceived auditory source width, auditory spatial acuity, and spatial unmasking. Three auditory environments were simulated and auralized using ODEON to vary interaural coherence (IC): (1) a control anechoic environment, (2) a classroom designed to meet classroom acoustics standards (IC = 0.58), and (3) a classroom of the same size with more severe reverberation (IC = 0.37). Individually measured head-related transfer functions were used to binaurally reproduce the auralized signals over headphones. We hypothesize that interaural decorrelation, the result of increasing reverberation, will broaden the perceived auditory source width with a cascading effect of reduced auditory spatial acuity and subsequently poorer spatial unmasking. Preliminary data from normal-hearing adults will be presented. [Work supported by NIH R21DC020532.]
“I feel like a pack a day smoker”: Teacher and student voices from noisy classrooms
Authors: Millett Pam
Published: July 2024

Concerns about the effects of poor classroom acoustics on student learning (particularly on students who are deaf or hard of hearing) have been expressed since the 1950s, yet research continues to indicate that poor classroom acoustics are both common, and related to poorer student outcomes in academic achievement, attention, behavior, and most recently, mental health. Teachers are not immune to the detrimental effects of noise; for them, research indicates a higher incidence of voice problems, absenteeism and job stress. However, little is reported about what teachers and students themselves have to say about their experiences attempting to learn under adverse listening conditions, and what changes for them when acoustical conditions improve. Their voices are largely missing from the research literature but they illuminate the problem in ways that quantitative data does not always capture. This presentation by an educational audiologist with over 35 years of experience in classrooms will provide an overview of the research on learning under adverse listening conditions, with a focus on representing teacher and student voices through qualitative research and anecdotal reports. The title is a quote from a teacher describing her voice problems and fatigue after a day of teaching.
Surfacic characterization of soft tissues biomechanical properties using impact-based methods: A comparative study
Authors: Bouffandeau Arthur , Rosi Giuseppe , Bensamoun Sabine , Flouzat-Lachaniette Charles-Henri , Nguyen Vu-Hieu , Haiat Guillaume
Published: July 2024

Various methods have been developed to assess the skin stiffness in order to assist the clinician for therapeutic monitoring or these diagnoses. The objective of this work was to compare the performances of a new acoustical characterization method based on impact analysis with those of two existing approaches, namely (i) a suction device, the Cutometer®, and (ii) a digital palpation tool, the MyotonPro®. This new impact analysis method is based on the analysis of the temporal variation of the force obtained during the impact of an instrumented hammer on a cylindrical punch placed in contact with a soft tissue mimicking phantom (Technogel®). The performances of the three aforementioned techniques (sensitivity and resolution) were assessed using homogeneous or bilayer structures with various thickness and rigidity, formed by different soft tissues mimicking gel pads. The impact analysis based method (IBAM) was two times better than the other two approaches in terms of reproducibility and sensitivity. The axial resolution of the IBAM was around 20 times better compared to the two other methods. The results open the way for the development of a cheap, non-invasive and objective method that could be used in the future in the cosmetic industry and in dermatology. This project has received funding from the projects OrthAncil (ANR-21-CE19-0035-03) and from the project OrthoMat (ANR-21-CE17-0004).
Validation and verification of models for setting SONAR system requirements
Authors: Cooper Jennifer , Dougherty Jean , Johnson Marina
Published: July 2024

When determining requirements for a SONAR system as a whole, typically very high-level requirements such as number of detections and total false alarms allowed per unit time must be converted into specific requirements for system components. These requirements may include array requirements like hydrophone count and position. Validation of probability of detection via sea test is fraught with complications, not least of which is environmental uncertainty. As a precursor, it is generally advisable to approach and attempt to validate models for each term in the SONAR equation one at a time. The approaches to validation vary depending on the term and can range in complexity from comparison to analytical solutions, to comparison with alternate available models, up through data collections at sea. Each of these approaches comes with its own challenges and limitations, which are discussed.
Ultrasound tongue imaging of vowel spaces across pitches in singing
Authors: Chan May Pik Yu , Kuang Jianjing
Published: July 2024

One important technique in singing is vowel modification: the adjustment of the resonance space based on the sung pitch for more efficient voice production. We explore whether vowel modification is a learned technique for enhanced acoustics, or if it is a necessary articulatory adjustment for high pitch production. 16 participants without vocal training participated in a singing experiment with ultrasound tongue imaging. Participants were asked to sing sets of English vowels across their comfortable pitch range rising by semitone in a steady tempo, resembling a vocal warm up exercise. Participants sang 5 sets of vowels in total, each set consists of 5 target vowels ([i], [ɛ], [æ], [ɑ], [u]) in randomized order with 1 filler ([ɔ]) closing each breath group. Images of tongue position were splined using DeepLabCut. Preliminary results show that untrained singers tend not to adjust their tongue positions by pitch, though cases of tongue lowering occasionally occurred, particularly for the participants who sing a wide pitch range. In contrast, additional pilot data from 2 trained operatic singers showed gradual tongue adjustments across their pitch range, neutralizing vowel contrasts at their highest pitches. We discuss findings with respect to vowel-pitch interaction, drawing implications on theories of voice production.
Short-term retention of popular music in older adults: Support for a plasticity theory of implicit music knowledge acquisition
Authors: Cohen Annabel J. , Collett Corey , Gallant Kristen
Published: July 2024

Based on our Plasticity Theory of Implicit Music Knowledge Acquisition (PTIMKA), we tested the hypothesis that adolescence is a sensitive period for acquiring musical information and lifelong musical grammar. Older adults (N = 27, mean age = 65.7 years; SD = 6.7) identified artist, title, and year of popularity and rated their familiarity for short excerpts of 36 songs popular between 1962 and 2021. Knowledge and familiarity were greater for music popular during the participants’ adolescence. A subsequent surprise retention task required participants to choose which of 2 excerpts had been presented in the first task; for each of 36 trials, targets and foils represented the same era of popularity. Retention (dêžŒ) scores and confidence in retention judgment were higher for the songs popular during adolescence, even though targets of all eras had just been presented in the previous 15 minutes. It is argued that popular music styles congruent with an adolescence-established grammar were more accurately encoded than styles violating this grammar, as would songs popular before or after adolescence. Prior data from younger adults showing trajectories opposite to those for older adults as a function of decade of popularity are further consistent with this interpretation and with PTIMKA. (Work supported by NSERC)
Dose error correction using simulation extrapolation for community noise dose-response modeling
Authors: Vaughn Aaron B. , Cruze Nathan B. , Boucher Matthew , Doebler William
Published: July 2024

The objective of this work is to provide a framework to account and correct for dose error in dose-response modeling due to measurement uncertainty. Error in noise measurements, especially in the case of limited monitoring locations in a community, can lead to an attenuation or misestimation of parameters in dose-response models. This error can result in overpredicted annoyance at lower doses and underpredicted annoyance at higher doses. Simulated data in the present work are based on previous NASA community studies and incorporate a notional design for future studies with the X-59 aircraft. Several populations of different annoyance response sensitivities are included. Simulation extrapolation (SIMEX) is used to correct for the dose error in a simple, fully pooled logistic regression. Results indicate the negative impact of attenuation is greatly diminished for all amounts of dose error considered, regardless of a population’s annoyance sensitivity. Therefore, SIMEX can help produce a more accurate dose-response relationship.
Aircraft noise contours—From everything for everyone to nothing for anyone
Authors: Novak Colin , Jovanovic Julia
Published: July 2024

Aircraft noise exposure contours were originally intended as a tool to facilitate compatible land use in the vicinity of airports. The simple concept was for authorities to use historic data and reasonable predictions for near future demands to create a map that identified areas of high aircraft noise impacts. Municipalities and planners would refer to this map to determine appropriate zoning around the airport, restricting noise sensitive development in high noise exposure areas. With time, different demands and applications of the noise contours emerged. Some stakeholders demanded longer term forecasts to allow for planning farther into the future. Some co-opted contours as a PR tool to suggest reduced impacts on communities. Some began using noise contours as a tool to protect against encroachment. Others began to look to noise contours as a representation of daily acoustic conditions in areas surrounding the airport. In Canada, a lack of oversight and guidance for the selection of inputs parameters for noise models, make it such that noise contours have become a product illustrating whatever their creator intends, lacking objectivity and scientific rigour. This research demonstrates how noise contours can be designed to achieve desired results by modulating different input parameters.
Deconvolution of spatially averaged shock wave forms
Authors: Hart Carl R. , White Michael J.
Published: July 2024

Noncontact optical methods (e.g., shadowgraphy, schlieren, and interferometry) allow visualization of propagating shock waves, avoid sensor-field interaction, and retain the potential for very high bandwidth. The heterodyne Mach-Zehnder interferometer produces quantifiable noncontact samples of the accumulated phase shifts induced by a shock wave, as viewed through its beam projection. This instrument is commercially available as a Laser Doppler Vibrometer (LDV). For shocked wave fields in air obeying spherical symmetry, point values for density and overpressure can be inferred. An important shortcoming for inference quality is the finite spatial dependence of the probe beam cross section, the profile shape itself serving to limit both the spatial resolution and the measurement bandwidth. We propose to model both of these effects of spatial averaging by constructing a model waveform and a model beam profile, convolving them, and comparing the result to synthesized LDV output. Mismatch between the convolved result and spatially averaged measurement can be quantified by a cost function, which is minimized via gradient descent.
Development of an arrayed ultrasonic sensor using surface plasmon resonance (SPR)
Authors: Dezao Kota , Kitajima Shouta , Matsukawa Mami
Published: July 2024

Surface plasmon resonance (SPR) ultrasonic sensors are non-resonant and expected to show flat frequency response over a wide frequency range. Then, the sensors seem suitable for the detection of photoacoustic waves. We have developed a simple glass prism SPR sensor with thin Ag layer (deposited by an electron beam evaporator) and checked the frequency response as a function of Ag area diameter. The diameter of 1 mm was sufficient to obtain better frequency response than that of the calibrated needle transducer in the range of 2.5 to 7.0 MHz. By covering a very thin Au film on the Ag layer, we succeeded in longer working time (>6 months) of the sensor. An array-type SPR sensor (5 × 5, diameter of each sensor 1 mm) has also been fabricated to evaluate pressure distribution of ultrasonic waves. The response of each sensor was similar, telling the high reproducibility of the sensor fabrication.
Sound-field image denoising using deep neural network considering physical characteristics of sound
Authors: Urata Daisuke , Oikawa Yasuhiro , Ishikawa Kenji
Published: July 2024

This paper presents a method of denoising utilizing deep neural networks (DNN) in sound field images measured by optical methods. Optical sound measurement has attracted much attention because of its capability to visualize sound field with high spatial resolution from a distance, which is difficult with conventional microphones. However, optical methods have the issue of the measured sound-field images often being heavily distorted by noise. This is caused by the weak phase of light changed by sound. Conventionally, noise-reduction filters considering the physical properties of sound have been known to be used for sound-field denoising. In this background, we propose a DNN-based sound-field denoising method that takes into account the physical properties of sound. In the DNN, a network architecture originally used for denoising natural images is employed, and we integrate loss functions based on the Helmholtz equation. Additionally, a 2D sound field dataset obtained from numerical acoustic simulation with random parameters is used during the training. Numerical and experimental data comparison experiments showed that the proposed DNN-based sound-field denoising outperformed the previous non-DNN methods.
Sports and linguistics pedagogy
Authors: Kennedy Robert
Published: July 2024

The domain of organized sports offers a unique circumstance to explore a wide range of fundamental concepts in linguistics classrooms. We present an overview of a pedagogical model that engages students of linguistics using data from sports oriented settings, with frequent reliance on peer-reviewed literature. The course model incorporates three domains of language behavior: (a) lexis, and the interplay of semantic specialization and sociocultural indexation of specialized sport-oriented vocabulary; (b) sports announcer talk, a spoken broadcast register whose study enables a novel exploration of syntactic nuance; (c) participant interaction with each other and with the media, which demonstrates fundamentals of pragmatic inference in spoken communicative exchanges. Some course topics span more than one of these domains. Nickname creation, for example, is phonologically and phonetically driven, with gradient effects that adhere to constraints of brevity and clarity, yet linked to sociocultural indexicality. While no single textbook serves as an appropriate primary text for such a course, the beneficial outcomes for students are numerous. Aside from the primary goal of applying linguistic concepts to an engaging domain, students probe a variety of published works that examine sports/language interactions, demonstrating a broad sample of research methods and theories.
Differences in prominence-related acoustic measurements in L2 read speech as a function of L1 framing typology
Authors: Diantoro Carissa A. , Sung Hakyung , Baese-Berk Melissa M.
Published: July 2024

Speech production in a non-native language is often influenced by their first language’s (L1) phonology. One factor that might affect their production prosodically is typological differences in event construal, specifically motion events. Building on this concept, prior studies on gestures and spontaneous speech show that how speakers frame motion events in their L1 can transfer to their second language (L2) through grammatical patterns. However, no study has looked at how L1-L2 differences in framing motion events may affect speakers’ L2 production prosodically. To explore whether those differences affect how L2 speakers prosodically produce motion events, this study collected read speech from two spoken corpora of L2 English learners. We chose L2 learners from different L1 backgrounds that differ in the way they grammatically construct motion events. English production from Korean and Turkish L1 speakers (which are typologically similar) were compared to that of L1 German speakers (which is typologically similar to English), along with productions by L1 English speakers. Duration and various acoustic measurements of pitch and intensity were extracted and analyzed. Results indicated some similarities among learners of the same typology along with differences between the L1 and L2 English speakers. Implications on conceptual transfer will be discussed.
Distributional learning of non-native tone contrasts by older adults after training and overnight consolidation
Authors: Chui Yin-To , Lai Susu , Qin Zhen
Published: July 2024

Despite decline in psychoacoustic and statistical learning (SL) abilities, older adults demonstrate remarkably intact perceptual learning in both L2 (tone-word learning) and L1 settings (perceptual adaptation to accented/noise-vocoded speech) but show limited transfer of learning to untrained stimuli. This study tests whether perceptual learning is maintained in an implicit statistical learning task where older adults learn L2 tonal contrasts through exposure to probability distributions of tonal tokens, which may pose higher requirements on both psychoacoustic and SL abilities, and whether sleep-dependent consolidation helps the generalization of perceptual knowledge. L1-Cantonese older adults learned to discriminate a perceptually difficult level-falling tone contrast following a pre-test, training, post- training overnight interval. Training stimuli were synthesized by interpolating naturally produced Mandarin level and high-falling tones into six equidistant steps. Participants either heard a bimodal (two-peak resembling level-falling categories) or unimodal distribution (single-peak) consisting of 256 tokens. ABX discrimination task was administered for testing, with tokens by two genders and on two pseudo-syllables to test generalization. Pilot data of 14 participants showed a trend of group effect with the bimodal group outperforming the unimodal group after training and sleep-dependent consolidation, showing that perceptual learning is maintained in a paradigm that relies heavily on psychoacoustic and SL abilities.
Revisiting rapid accent adaptation with computational modeling
Authors: Chiu Samantha , Moore Leo , Kutlu Ethan
Published: July 2024

Studies on accent adaptation report that monolinguals can rapidly adapt to a novel foreign accent with short exposure or training (Baese-Berk et al., 2013; Clarke & Garrett, 2004; Maye et al., 2008). While most of these studies rely on self-reported monolinguals, there is great variability in how much language diversity monolinguals encounter regularly (Castro et al., 2022). We return to this question of rapid accent adaptation in monolinguals through computational modeling where linguistic diversity is directly controlled. We simulate monolingual speech perception using PyTorch’s Wav2Vec2 model (Paszke et al., 2019), pre-trained on the Librispeech corpus with American-accented English (Panayotov et al., 2015). We replicate the experimental design of Baese-Berk et al. (2013) by fine-tuning this model on a single accent (n = 150 sentences across 5 talkers) and multiple accents (n = 30 sentences for each of 5 talkers). Preliminary results find that exposure to a single accent (68.6% correct) or multiple accents (69% correct) does not induce accent adaptation to a novel accent (no accent training = 69% correct). We predict that exposure to a single or multiple accents will increase accuracy but requires many additional hours of exposure. We discuss implications of our models against accent adaptation studies.
Effects of quality of initial exposure stimuli on speech intelligibility
Authors: Kim Seung-Eun , Goldrick Matthew , Bradlow Ann
Published: July 2024

Listeners can use lexical information to drive adaptation to talker-specific speech characteristics with a small amount of exposure. This suggests that adaptation may be strongest when listeners are initially exposed to speech in a condition that facilitates word recognition. This was tested by examining the intelligibility of second-language (L2) speech-in-noise when stimuli were initially presented in Quiet versus low signal-to-noise ratio (SNR) conditions. Recordings of 10 L2 English talkers were tested. For each talker, 120 sentences were mixed with speech-shaped noise ranging from −4 dB to 8 dB in steps of 2 dB and in Quiet (15 sentences at each SNR). These stimuli were presented from lowest to highest SNR (forward; −4 dB to Quiet) in one group of L1 English listeners (n = 10/talker) and from highest to lowest SNR (reverse; Quiet to −4 dB) in the other (n = 10/talker). The results showed that early exposure to a clean signal led to better speech perception. At lower SNRs, word recognition accuracy in the reverse order was significantly higher than the forward order, resulting in a steeper slope of psychometric function of intelligibility in the forward versus reverse condition. The quality of initial speech input may influence talker adaptation, particularly in adverse listening conditions.
Non-native clear speech increases intelligibility but not through improved word segmentation: Evidence from a visual-world eye-tracking study
Authors: Smith Madeline , Guo Zhe-chen , Smiljanic Rajka
Published: July 2024

Listener-directed hyperarticulated clear speech produced by native (L1) talkers improves word segmentation and reduces lexical competition. Less is known about whether non-native (L2) clear speech also confers such benefit. In a visual-world eye-tracking study, we investigated if L2 clear speech improves word segmentation and the time course of the benefit for native listeners. Forty L1 English participants heard sentences produced in conversational and clear styles by a highly intelligible L2 English / L1 Spanish speaker with a discernable non-native accent. Sentences contained a target word (e.g., doll) with which a corresponding competitor overlapped phonemically (e.g., dolphin), creating temporary ambiguity with the target and the following word’s onset (e.g., doll found). Each recording was presented in quiet alongside pictures of the target, competitor, and two distractors. Participants were instructed to select the picture mentioned in the sentence they heard. No significant clear speech segmentation advantage was found; the proportion of looks to targets over competitors indicates similar time course of disambiguation in both conversational and clear speech. The results suggest that L2-accented clear speech with its deviations from the target-language- specific modifications and greater phonetic variability increases signal uncertainty resulting in no benefit for word segmentation even though word recognition was improved.
Fundamental frequency patterns across gender, task, and language in Spanish-English bilinguals
Authors: Contreras June M. , Merritt Brooke
Published: July 2024

Speaking fundamental frequency (SFF) patterns are known to vary by language and speaker gender. Relatively little data exist for SFF patterns among cisgender and transgender speakers, especially those who speak languages other than English. Further, speaking task (e.g., read versus spontaneous speech) may impact SFF patterns. This study examined SFF patterns in Spanish-English bilinguals of varying gender identities. Twenty-four speakers (8 cisgender men, 8 cisgender women, and 8 transgender women) recorded a read passage and spontaneous speech in Spanish and English. SFF measures of minimum, maximum, range, and median were found to be stable across speech tasks and languages. A significant effect of gender was found. Cisgender women on average produced the highest values of minimum, maximum, and median SFF and largest SFF range. Cisgender men produced the lowest values and smallest range. Transgender women produced SFF measures within an intermediate range of cisgender men and women. Compared to monolingual English speakers, Spanish-English bilingual cisgender women had a larger SFF mean for both Spanish and English, cisgender men had similar SFF means for both Spanish and English, and transgender women had a slightly larger SFF mean for both Spanish and English.
Detecting ringed seal vocalizations in multiple environments using deep learning
Authors: Zammit Karlee , Halliday William D. , Frazao Fabio , Fabbro Sebastien , Dosso Stan
Published: July 2024

Deep learning methods have recently been successfully applied to create a variety of automated acoustic detectors in the field of marine bioacoustics. Automated detectors are essential for analyzing large volumes of passive acoustic monitoring (PAM) data since manual analysis is prohibitively time-consuming and costly. PAM is the primary method for obtaining data on species which are endemic to remote regions, such as the Canadian Arctic. Arctic ringed seals are listed as a Species of Special Concern in Canada due to a loss of critical habitat caused by the effects of climate change. Here, ResNet, a convolutional neural network architecture, is trained on thousands of examples of ringed seal vocalizations recorded at various locations within the Canadian Arctic to create the first practical automated ringed seal detector. The network achieves a precision of 0.89, recall of 0.80, and F1 score of 0.85 when tested on 215 five-minute recordings from sites included in the training process. To improve the generalizability of the detector for new locations, fine-tuning is performed using a small subset of annotated data from new sites. The detector will be available as an open-source tool for researchers to use as the basis for further development of new automated detectors.
Using convolutional neural networks to select the optimal wavelet for audio compression
Authors: Pies Shaun , Leftwich Kendal , Ioup Juliette W.
Published: July 2024

The vast amount of data generated and stored across domains is overwhelming. Noteworthy examples include the Event Horizon Telescope using 3.5 petabytes for the first black hole image, LIGO amassing 4.5 petabytes, and CERN with 487 petabytes. This research addresses the challenge of data storage and transmission using machine learning and wavelet analysis. The goal is to create an efficient data compression method that significantly reduces storage needs without compromising data integrity. Wavelets, mathematical tools which break down signals into coefficients, show promise for compression. Choosing the right wavelet is crucial; our research demonstrates that machine learning can effectively solve this problem. By training a convolutional neural network on spectrograms of audio files, we identify the optimal wavelet for data compression, achieving up to 50% compression with minimal loss.
Machine learning for analysis of wind farm noise
Authors: Lai Heather L. , Balant Anne C. , Tsai Chih-Yang
Published: July 2024

Two challenges associated with analyzing acoustical data from wind farms are: 1) separating turbine sounds from environmental sounds and 2) classifying acoustical samples into different types of wind turbine noise based on acoustic characteristics. Machine-learning methods for classifying general environmental sounds have been developed using large human classified databases (e.g., YAMNet), but only a few studies have targeted classification of wind farm noise (WFN) specifically. Techniques for classifying wind farm noise have focused on identification of amplitude modulation (AM) using both traditional methods such as low frequency peak prominence (IOA method) and machine learning methods using both targeted AM acoustics features and more general deep acoustic features. To address these two challenges, we are developing a multi-echelon machine learning framework to identify and classify noise from wind farms using publicly available windfarm data and open-source software. The first echelon provides an automated method for identifying WFN samples that are free of environmental sounds. The second echelon uses machine learning to classify these wind farm noises according to the degree of AM, prominent tones, and other factors that might contribute to the human response and are incorporated in the metrics used or potentially used to assess compliance with regulations.
Mid-frequency convergence zone propagation
Authors: Akins Franklin H. , Hodgkiss William , Kuperman William
Published: July 2024

Convergence zone propagation has a cycle distance of order 50 km with most of the path spent below the thermocline. Calculations using Garrett-Munk statistics and rays computed with a smoothed background sound speed profile over this single cycle predict propagation in the partially saturated regime and an integration time of 500 seconds (time spent in a single output bin of a discrete Fourier transform). Parabolic equation simulations with synthetic fine structure and ocean dynamics validate the ray-based calculations. Data of narrowband transmissions from 1.5 to 7.5 kHz from a shallow towed source (150 m) to a shallow drifting array (150 m) depth at a range of 59 km demonstrate smoothly varying phase in a beam permitting coherent integrations of 3.5 minutes. The shorter integration time in data is consistent with non-uniform motion estimated from GPS.
Issues in mid-frequency sound intensity fluctuation on the Washington Shelf
Authors: Hefner Brian T. , Tang Dajun , Mickett John B. , Harcourt Ramsey R. , Xu Guangyu , Thorsos Eric I. , Prakash Kumar
Published: July 2024

Strong mid-frequency sound intensity fluctuations were found on the Washington shelf during an experiment in the summer of 2022. The Scintillation Index (SI) of integrated sound energy on single channels at 20 km range was near unity for both 3.5 kHz and 6.0 kHz signals. Accompanying oceanographic measurements from moorings and a towed profiling system revealed sound field variability at multiple time and spatial scales caused by linear and nonlinear internal waves, internal tides, and coastal trapped waves. While the 2022 dataset provides valuable information for addressing issues on intensity fluctuation, additional experimental data are needed to understand the impacts on active and passive mid-frequency sonar systems. To that end, a second Washington Shelf experiment is being planned for the summer of 2025. This talk will discuss the planned measurements and the range of issues to be addressed. These include the frequency-dependence of SI over 1–10 kHz, broadband fading, vertical and horizontal coherence, and the impacts of variability on propagation in subsurface ducts. These measurements are important for investigating fundamental oceanographic causes of sound fluctuation as well as for the design of appropriate signal processing methods. (Work supported by the Office of Naval Research.)
Enhancing cancer treatment through solid tumor fractionation with nanodroplet-mediated histotripsy and immunotherapy
Authors: Glickstein Bar , Ilovitsh Tali
Published: July 2024

Checkpoint inhibition holds great promise in enhancing the body's immune response against cancer for durable and widespread anti- tumor effects. However, its efficacy in solid tumor therapy faces challenges such as limited immune cell infiltration and an immunosuppressive tumor microenvironment. This study introduces a cancer therapeutic platform, combining nanodroplet (ND)-mediated low-frequency histotripsy with anti-PD1 (aPD1) checkpoint inhibition. NDs, with their ability to penetrate capillaries and extravasate into tumor tissues, present a promising feature for noninvasive tumor treatments. The proposed method involves a two-step approach for low-energy ND-mediated histotripsy. First, NDs are activated volumetrically using a rotating imaging probe into cavitating gas bubbles. Subsequent low-frequency ultrasound implodes vaporized NDs, inducing tumor fractionation, tissue necrosis, and enhanced immune-cell infiltration, creating a T-cell–inflamed tumor. The goal is to amplify immunotherapy, advancing cancer treatment by targeting both the tumor and its microenvironment. Demonstrated in a breast cancer mouse model, the two-step approach showed significant lesions and tumor debulking. Combining aPD1 checkpoint inhibition further enhanced immune-cell infiltration and reduced tumor growth. Our findings demonstrate the potential of NDs with low-frequency ultrasound and immunotherapy for efficient noninvasive tumor treatment.
Learning to read an acoustics equation as a descriptive sentence
Authors: Russell Daniel A.
Published: July 2024

Teaching theoretical acoustics at the graduate level requires the use of mathematics, and often the math can be difficult enough that students get lost in the math and can’t see the underlying physical concepts the equations are describing. What many students don’t realize is that a mathematical equation is just a shorthand notation that condenses a long and complicated sentence into a few symbols. Being able to read and interpret an equation as a sentence (which is more than just reading the names of the symbols or variables) is a valuable skill that can help students grasp the underlying physical concepts. This talk will provide several examples from fundamental acoustics of how helping students learn to read and interpret mathematical equations as sentences can help them reveal and grasp the physical concepts the equations are describing.
A tutorial and assignment on the analysis and syntheis of music to provide acoustic foundations for courses in the Psychology of Music and in Music Cognition
Authors: Cohen Annabel J.
Published: July 2024

Students in courses in the Psychology of Music and in Music Cognition benefit from an understanding of aspects of musical acoustics. A tutorial assignment has been developed to provide hands-on experience in synthesizing acoustic elements and analyzing real music using Audacity®, freely downloadable software. The tutorial emphasizes visualizing waveforms and spectrographs of target sounds. For the synthesis component, students generate sine tones related by small integers on separate tracks and combine the tracks to create complex waves. Students must answer questions regarding frequency, amplitude, pitch, loudness, and sound quality. They are also asked to synthesize a sequence of successive notes of the chromatic scale, so as to understand the significance of the semitone ratio 21/12 (i.e., 1.05946), and they are asked to synthesize a sequence of successive notes from the diatonic scale. For the analysis component of the tutorial, students download a favourite piece of music, provide waveform and spectrographic representations, and answer questions about the representation of pitch, loudness, time and timbre. They also locate auditory repetitions and identify different sections of their piece. The students are asked to summarize what they have learned from the assignment. The assignment can be adapted for work in teams, and a detailed grading rubric facilitates student evaluation.
Viewpoints on math in acoustics education and their reflections in the acoustics program's curriculum at Purdue University
Authors: Liu Yangfan , Li Junfei , Bolton J. S. , Davies Patricia
Published: July 2024

Faculties in the acoustics and noise control program at Purdue university will share their viewpoints on the roles of mathematics in acoustics education and math instruction practices in the acoustics curriculum at Purdue university. It is suggested to consider mathematical training from two prospective: (1) teaching math techniques and (2) cultivation of a mathematical mindset. Opinions will be shared on how each math training aspect benefits acoustics students with engineer careers and research careers as well as the long-term influences of math education on industry-academia collaboration. We will also briefly discuss how these views on math education are reflected in Purdue’s current acoustics curriculum and could guide further improvements of the curriculum.
Acoustic measurements of wind farm noise inside homes and comparison with the ISO 9613 standard
Authors: Berardi Umberto , Iannace Gino , Trematerra Amelia , Bevilacqua Antonella Bevilacqua
Published: July 2024

To achieve the energy transition objectives, many wind farms are installed to produce electricity by exploiting wind energy. The production of electricity through wind farms is widespread in the world. One of the problems complained about by people who live near wind farms is the noise emitted by the rotation of the blades. This work reports acoustic measurements inside homes near wind farms. The acoustic measurements were performed for different wind speeds and directions. Furthermore, to verify the effectiveness of the simulation method of the propagation of the noise generated by wind farms, the measured values of the sound levels were compared with those obtained from the numerical simulations using the provisions of the ISO 9613 standard, and the wind turbines are considered point-like sound sources. The comparison between the measurements carried out in the field with the theoretical simulations has highlighted that the calculated levels are lower than the measured ones, this means that in the acoustic impact forecasting procedures, the noise emitted by the wind farms is underestimated and is one of the reasons why the Wind farms in operation are a source of complaints from the populations living nearby.
Empowering residents of communities near wind farms to record and document wind farm noise through the use of a phone app
Authors: Lai Heather L. , Balant Anne C. , Riegel Kimberly A.
Published: July 2024

The impact of disturbances caused by wind farm noise (WFN) on residents can be difficult to predict. In talking with advocates for residents living near wind farms, it has become clear that some residents are negatively impacted by WFN, but the specific features that cause the greatest impacts are not well understood. A few studies have been published correlating in-home recordings of WFN with annoyance ratings by occupants in nearby residences, and some local municipalities have recorded SPLs at residences (such as an upstate NY town appointed volunteer noise officer who measures sound pressure levels on the property of concerned residents), but the vast majority of residents’ experiences go undocumented. In this talk, we will present a plan for using a cell phone app, “Auditive,” originally developed for collecting users’ responses to urban noise to provide residents living near wind farms with the opportunity to document their experiences with WFN while making simultaneous recordings. These recordings in conjunction with the user ratings will allow identification of qualitative aspects of WFN that cause the most annoyance from a large sample of individuals and may also provide a sense of agency for residents who are most negatively affected.
Topological acoustic sensing using the geometric phase
Authors: Runge Keith , Deymier Pierre A.
Published: July 2024

We introduce a method, topological acoustic sensing, which exploits changes in the geometric phase of acoustic waves to sense defects in some structure or environment. This method is illustrated in two cases of perturbations taking the form of (1) a mass defect located on an array of coupled acoustic waveguides, and (2) a small subwavelength object on a flat surface submerged under water. We represent the state of the acoustic field in the unperturbed and perturbed cases as multidimensional vectors. The change in geometric phase is obtained by calculating the angle between those vectors. This angle represents a rotation of the state vector of the wave due to scattering by the perturbation. By exploiting sharp topological features spanned by the acoustic field multidimensional state vector, we show that this geometric phase sensing modality can have higher sensitivity than magnitude-based sensing approaches.
An exploratory investigation of acoustic features underlying arousal and valence perception of vocalizations from non-speaking individuals
Authors: Radhakrishnan Simon M. , O'Brien Amanda M. , Quatieri Thomas , Johnson Kristina T.
Published: July 2024

Emotion perception of vocalizations, especially from individuals with no or few spoken words, remains an underexplored topic in acoustical research. The aim of this exploratory study was to identify acoustic features within non-speech vocalizations correlated with perceived arousal and valence. 364 vocalizations were selected from the open-access ReCANVo dataset, comprising non-speech communicative sounds by non-speaking individuals with autism and neurodevelopmental disorders. 108 listeners independently rated each vocalization for arousal and valence on a 5-point Likert scale (78624 total ratings). We then used random forest and elastic net regression techniques to determine correlations between acoustic-based features and perceived affect. Using 4 published (e.g., GeMAPs) and 2 custom feature sets (dim 12, 28) encompassing duration, intensity, pitch, formant, and spectral centroid features, we evaluated each model using R-squared and mean-squared error. Our 12-feature custom elastic net model achieved the highest performance for predicting arousal (R-sq = 0.763, MSE = 0.075), with intensity features weighted highest, comparable to other sets. Our 28-feature random forest model, which included vocal quality features, significantly outperformed other models in valence prediction (R- sq = 0.491; MSE = 0.139, p < 0.001). While further validation on a held- out test set is essential, these exploratory results expand our understanding of affective acoustic features of non-speech sounds from individuals with neurodevelopmental disorders.
Auditory brightness in room reverberation
Authors: Bullard Chad , Lentz Jennifer
Published: July 2024

This work examines the impact of room reverberation on the auditory perceptual brightness of sounds. We hypothesized that room size would impact the perception of brightness, with smaller rooms (less reverberant) leading to sounds being perceived as more bright than larger rooms. We generated single-note instrument sounds from five different instruments using Logic Pro which were reverberated in three different-sized simulated rooms. Reverberant stimuli were presented in sequential room-size pairs (small-medium, small-large, medium-large) in a randomized order. Participants (15 musicians) were asked to rate the brightness of the second sound as compared with the first using a Likert-style scale, and the stimuli were blocked by instrument such that in each block a participant would only hear room-size comparisons of one instrument. Results were analyzed using an ordered-probit regression of the brightness ratings against the spectral centroid of the stimuli. We found no clear effect of room size. However, brightness ratings were weakly correlated with the average spectral centroid as shown in previous literature, and a stronger correlation was found with the steady-state portion of the sound. This suggests room size has little effect on brightness. Future work should examine the effect of different segments (e.g., attack, steady-state) on perceived brightness.
Acoustic cues in perception of reduced speech
Authors: Kim Song Yi , Warner Natasha
Published: July 2024

In conversational speech, sounds undergo reduction and deletion, which challenges listeners to decode reduced forms using various cues. Previous research argues for the predominance of acoustic cues in a study of listeners’ perception of reduced speech such as “he’s” vs. “he was”, which can both be realized [É¨z]. Analyzing data from a previous perception experiment (Warner et al., Brain Sci., 2022), this study explores what types of acoustic cues listeners use to process reduced speech. Ambiguous [É¨z] with low second formant (F2) or long duration might be perceived as past due to an additional consonant (/w/) and potential contractions (low F2 as a cue to /w/). Low F2 is expected to result in smaller Bark F2-F1 and larger Bark F3-F2. Current study tests whether the stimuli show acoustic differences in the predicted direction and whether the formant and duration measures correlate with listeners’ identification of tense. It was found that there are no significant acoustic differences between past and present forms due to reduction, but that listeners significantly associated smaller Bark F2-F1 with past tense in singular verbs and longer duration with past tense in plural verbs. This confirms listeners' use of the predicted acoustic cues in perceiving reduced speech.