bluuebunny/crossref_metadata_2025 huggingface dataset:
Listening effort assessed using engaging, naturalistic materials
Authors: Johnsrude Ingrid , Bain Matthew T. , Motala Aysha , Herrmann Björn
Published: December 2020

Hearing loss in older people is typically diagnosed long after they begin to find speech comprehension effortful in the presence of background sound. Progress in measuring listening effort has been slow because the concept is ill defined, the materials typically used to measure it (simple sentences) may not motivate effortful listening the way that richer narratives do, and the cognitive abilities and brain networks that are most related to listening effort have not been systematically identified. We are examining the utility of engaging, naturalistic stories, compared lo isolated sentences, to measure listening effort with novel behavioural and functional magnetic resonance imaging (fMRI) methods that provide a window on the cognitive processes recruited to compensate for masked speech. We exploit the fact that naturalistic and engaging stories are known to activate much of the brain, in specific patterns that are timelocked to a story. The goal of the research is to develop a clearer understanding of the nature of listening effort, and begin to identify relevant markers in cognition and brain network activity, so that we can make more rapid progress on development of sensitive tests that will enable more timely, efficient, and beneficial fitting of hearing aids.
Using frequency-differencing to robustly localize distant sources in the deep ocean
Authors: Geroski David J. , Dowling David R.
Published: December 2020

Frequency-Differencing (FD) methods have proven successful for localizing distant sources both in the deep ocean [Geroski and Dowling, J. Acoust. Sci. Am. 146, 4727–4739 (2019)] and in the shallow ocean [Worthmann et al., J. Acoust. Sci. Am., 138, 3549–3562 (2015)]. These source localizing algorithms are based upon matching the phase of a product of measured complex field values, termed autoproducts, to a replica field that is calculated based on the user's knowledge of the environment, similar to Matched Field Processing (MFP). Unlike MFP, FD methods have proven to be robust to the problem of environmental mismatch in ocean environments. Because of the focus on demonstrating robustness to environmental mismatch, these efforts have provided little guidance for a user to apply such methods in the practice. This presentation explores the process of how to choose difference frequencies and difference frequency bandwidths to localize sources at long ranges in the deep ocean, as well as how to use snapshot averaging to improve FD source localization results. These results and limitations are demonstrated using measurements taken in the PhilSea10 experiment from moored sources as far as 450 km away from the vertical receiving array, as well as simulations mimicking acoustic propagation in this environment. [Sponsored by ONR.]
Dr. Jiri Tichy: A man missed not only for his technical contributions to science but for the personal support and encouragement he gave to his graduate students
Authors: Parkins John
Published: December 2020

Dr. Tichy was my co-advisor during my doctoral work at Penn State University. This work involved architectural acoustics, three-axis energy density measurements and feedforward active noise control in rooms. I was also a student of Dr. Tichy's, as I took his course on acoustic intensity. From the time I met Dr. Tichy, during my application interview for the graduate program, to the time I left the program, after a postdoctoral position in thermoacoustics, Dr. Tichy was not only supportive from a technical perspective but also from a personal one. In this presentation, I'd like to touch on Dr. Tichy's technical work, his impact on me as a researcher and also how he was an inspiring, warm and supportive mentor.
Speech intelligibility in auralized classrooms when the talker is wearing a face mask
Authors: Bottalico Pasquale , Murgia Silvia , Puglisi Giuseppina Emma , Astolfi Arianna , Kirk Karen I.
Published: December 2020

This study explored the effects of wearing face masks on classroom communication. We evaluated the effects of three different types of face masks (fabric, surgical and N95 masks) on speech intelligibility presented to college students in auralized classrooms. To simulate realistic classroom conditions, speech stimuli were presented in the presence of speech-shaped noise with a signal-to-noise ratio of + 3 dB under two different reverberation times (0.4 s and 3.1 s). The use fabric masks yielded significantly greater reduction in speech intelligibility compared to the other masks. Therefore, surgical masks or N95 masks are strongly recommended in teaching environments.
Higher speech levels in K-12 classrooms correlate with lower math achievement scores
Authors: Wang Lily M. , Brill Laura C. , Nord Jayden , Bovaird James
Published: December 2020

Sound levels in 275 K-12 midwestern classrooms have been logged every 10 s over two occupied school days (220 rooms over the 2015–2016 and 2016–2017 academic years) or four occupied school days (55 rooms in the 2017–2018 academic year). Measurements were made two or three times to capture data during both heating and cooling seasons. K-means clustering was used to group the data into times when speech was or was not occurring; then acoustic metrics were calculated from the clustered data. Demographic data and achievement data in the form of percentile ranks on math and reading tests were also collected for the students in each classroom and aggregated into classroom averages. Multivariate linear regression analysis on the initial dataset of 220 classrooms indicates that higher speech levels in classrooms correlate with lower math scores, with a significant interaction with the percentage of students receiving free or reduced-price lunches in the classroom. A statistically significant interaction is also found of non-speech levels and the percentage of gifted students in the classroom on reading scores. Data from the latter 55 classrooms are used to cross-validate the initial model. [Work supported by the United States Environmental Protection Agency Grant No. R835633.]
Adjoint-based optimization to minimize scattered pressure fields
Authors: Treweek Benjamin C. , Walsh Timothy , Sanders Clay M. , Aquino Wilkins , Parker Samuel D. , Haberman Michael R.
Published: December 2020

Acoustic and elastic metamaterials have shown potential for many different applications in wave manipulation and structural isolation. Minimization of a scattered pressure field has been identified as an important use for such materials, and a wide variety of designs have been proposed for this purpose. Several of these designs are difficult to manufacture (e.g., pentamode designs), and many others involve numerous tunable parameters and a large design parameter space (e.g., distributions of resonators). This presents a challenge for global search-based optimization and raises the need for gradient-based methods. In this work, adjoint-based, PDE-constrained optimization is used to improve the feasibility of minimizing a scattered pressure field via an optimal set of channels in an annulus surrounding a rigid scatterer. Two different optimization strategies are investigated: material identification, where the physical properties of each channel are treated as unknown, and force identification, where the magnitude and phase of the reflected field is treated as unknown at various patches on the annulus. Results are presented for both a single plane wave direction and multiple plane wave directions, as well as for both a single frequency and multiple frequencies. [S.N.L. is managed and operated by NTESS under DOE NNSA Contract No. DE-NA0003525.]
Free vibration of a kalimba tine model beam with offset boundary condition
Authors: Ludwigsen Daniel , Huizar Jesus
Published: December 2020

A study was conducted to better understand the offset boundary condition of the kalimba; this study explored the free vibration of a beam with one end free and the other end subject to an offset clamped boundary condition. The cantilever beam was resting on a table, which provided a solid boundary below the beam. The top surface of the beam was clamped at a variable distance from the table edge. The excitation was a constant initial displacement of the free end, after which the entire beam was free to vibrate. The spectra of beam vibration and the sound produced showed harmonic peaks at integer multiples of the fundamental frequency, in addition to mode frequencies expected with Euler-Bernoulli beam theory.
Noninvasive methods for quantifying sound post placement in a cello
Authors: Rokni Eric , Smallcomb Molly , Blanford Thomas , Shepherd Micah
Published: December 2020

The position and orientation of the sound post in violin family instruments has long been known to color the sound of the instrument. Small changes in the position of the sound post relative to the top and back plates of the instrument can result in clearly audible changes in the instrument's tone. Quantifying the effect of the sound post's placement on tone requires precise localization of the sound post. Luthiers have developed simple techniques to localize the post relative to the top of the instrument. Precisely localizing the post relative to the back, however, typically requires disassembly of the endpin. This talk will explore nondestructive and noninvasive techniques to localize the sound post relative to the back of the instrument. Results of these techniques will be compared for two cellos – one with a laminate construction and the other carved. Finally, the effects of differences in material properties on these localization techniques will be discussed.
The elastic constants measurements in a TI-6AL-4V eli alloy by ultrasound
Authors: Carreon Hector
Published: December 2020

In this paper, we report the calculation of the elastic constants such Poisson's ratio, elastic modulus and shear modulus deduced from the ultrasonic propagating equations with two types of ultrasonic vibrations named longitudinal and transverse waves. The ultrasonic propagating velocity is measured at the microstructural evolution in a Ti-6Al-4V medical alloy with two varying microstructures, bimodal and acicular respectively. The two different initial microstructures were treated thermally by aging at 515 °C, 545 °C, and 575 °C at different times from 1 min to 576 h to induce a precipitation process. Ultrasonic measurements of shear and longitudinal wave velocities, scanning electron microscopy (SEM) image processing and micro-hardness were performed, establishing a direct correlation with the measurements of the ultrasonic velocity and the elastic properties developed during the thermal treatment of the artificial aging. The results of the ultrasonic velocity show a very clear trend as the aging time progresses, which is affected by precipitation of Ti3Al particles inside the α phase. In this way, we can know, in a fast and efficient way, the elastic properties developed during the heat treatment of aging at long times, since the presence of these precipitates hardens the material microstructure affecting the final mechanical properties.
Simultaneous high-speed ultrasound and synchrotron x-ray imaging for monitoring melt pool dynamics in metallic additive manufacturing
Authors: Gillespie Jared , Yeoh Wei Yi , Lan Bo , Sun Tao , Kube Christopher M.
Published: December 2020

Fundamental to metallic additive manufacturing (AM) is the laser-powder-substrate interaction that leads to localized melting of metallic powder to a previously solidified substrate. The formation of the melt pool and the subsequent solidification dictate the resultant microstructures and properties of the processed materials, which then influence both part quality and performance. Open ended questions involving the optimization of process parameters for defect free and high performing parts remain at the heart of AM science. Further understanding of melt pool and solidification behavior is required to help answer these questions. In this presentation, 25 MHz ultrasonic shear waves are used to probe dynamic melt pool behavior in Al6061 by observing the scattering from the solid/liquid and liquid/gas boundaries. High-speed synchrotron x-ray imaging was employed simultaneously with the ultrasonic measurement for validation. Melt pool features observed in the x-ray images were then associated with features in the synced ultrasound measurement. Specifically, the scattered response tracked with the depth of the melt pool. Finite element models depicting wave-scattering were also used to predict wave scattering and help interpret the ultrasonic response. These preliminary results provide support for ultrasonic scattering as a promising method to evaluate melt pool behavior in metallic additive manufacturing processes.
Walking while listening and remembering: Dual- and multi-task costs
Authors: Helfer Karen , Freyman Richard , van Emmerik Richard , Banks Jacob , Clauss Michael , Dunn Lincoln , Tellerico Silvana
Published: December 2020

In day-to-day life people often need to perform more than one task at a time. Dual- and multi-task costs may occur in these situations. In the present study we examined the realistic situation in which people must communicate in an acoustically-challenging environment while walking. Participants (younger adults and middle-aged adults) performed a task of listening and responding to speech presented in competing speech. In this task, participants repeated back sentences presented from a front loudspeaker in the presence of two-talker same-sex speech maskers presented from loudspeakers to the right and left. In some conditions they were asked to also complete a memory task in which they were shown a sequence of four numbers and letters (e.g., “C9L3”) before the trial began and had to report that sequence at the end of the trial. These tasks were completed while either standing still or while walking on a treadmill. Gait parameters were measured using sensors attached to participants' wrists, legs, waist, chest, and forehead. This presentation will detail results of preliminary analyses designed to examine costs involved in performing these tasks simultaneously compared to individually in the two age groups. [Work supported by NIDCD 012057.].
Impact of phase distortion and phase-insensitive speech enhancement on speech quality perceived by hearing-impaired listeners
Authors: Zhang Zhuohuang , Williamson Donald S. , Shen Yi
Published: December 2020

Phase is important for speech since it contributes to the quality and intelligibility during speech perception. Many speech enhancement algorithms lack the ability to predict phase for speech reconstruction and apply the noisy phase instead. In this study, we investigated the influence of phase distortion on the speech-quality ratings of both normal-hearing (NH) and hearing-impaired (HI) listeners by applying different degrees of random phase on speech. In one set of conditions, the speech was embedded in babble noise at 4 different signal-to-noise ratios (SNRs) from -5 to 10 dB, while in another set of conditions, the SNR was fixed at 10 dB and the speech and noise mixture was presented in simulated rooms with reverberation times ranged from 100 to 1000 ms. The speech level was kept at 65 dB SPL for NH listeners; while amplification was applied to ensure the audibility for HI listeners. Ideal ratio mask (IRM) was used for speech enhancement. Speech-quality ratings were collected following the MUSHRA procedure and compared to two objective evaluation metrics (i.e., PESQ and HASQI). Results suggest that phase distortion has negative impact on speech quality for both NH and HI listeners and this effect becomes dominant when speech enhancement was applied.
Subphonemic variation detection and correction in cochlear implant users
Authors: Bakst Sarah , Niziolek Caroline A. , Litovsky Ruth Y.
Published: December 2020

The ability to detect and correct errors in one's own productions is crucial for intelligible speech. Individuals with normal hearing detect and correct even within-phoneme deviations while talking. Cochlear implant (CI) users receive spectrally-degraded auditory information, potentially filtering out subphonemic information and prohibiting error detection. The experiment here tested the threshold at which CI users could detect variation in the first and second formants (F1/F2), spectral peaks which are important for distinguishing vowel height and backness. We hypothesized that CI users may not be able to detect subphonemic differences in their speech, especially if those differences do not cross wide electrode boundaries in their frequency allocation tables. In an adaptive discrimination task, speakers distinguished versions of their own speech where F1 or F2 had been altered. Contrary to the hypothesis, some speakers were sensitive to acoustic differences that occurred within a single electrode band, suggesting that speakers may be able to use subphonemic information to constrain acoustic variability while talking. We will also present pilot data from a real-time altered auditory feedback experiment. Preliminary evidence showing opposition to the formant shift suggests that CI users may have access to and use acoustic detail to correct errors while talking.
Phonemic restoration in monolingual and bilingual listeners in a sentence context
Authors: Exton Erika L. , Newman Rochelle S.
Published: December 2020

Phonemic restoration, the illusion in which listeners perceive a word as intact when a phoneme is replaced by non-speech noise, has been shown in both adults and children (Warren 1970; Newman 2004). Phonemic restoration appears to have a lexical basis (Samuel 1997); however, bilingual listeners may be limited in their ability to engage this top-down skill because their lexical knowledge is necessarily less robust in a given language than that of their monolingual peers. Bilingual phonemic restoration has rarely been shown, particularly in sentences, but exploring it allows us to better understand the top-down linguistic factors of the effect. In the present study, monolingual and bilingual English speakers listened to and transcribed 92 low-predictability sentences in four conditions: no noise, pink noise throughout, pink noise-filled gaps, and silent gaps. Here “bilingual” includes both crib bilinguals and English L2 speakers. Preliminary results suggest that monolingual listeners show the standard phonemic restoration effect such that transcription is more accurate for filled-gap than silent-gap sentences, but that bilingual listeners do not. For bilingual listeners only, English verbal fluency scores are positively correlated with transcription accuracy in all three degraded conditions (noise throughout, filled-gap, and silent gap), suggesting that language proficiency contributes to listeners' ability to comprehend speech in various types of noise.
Intelligible nonnative-accented speech incurs a processing cost: Converging evidence from a behavioral and a physiological paradigm
Authors: Brown Violet A. , McLaughlin Drew J. , Strand Julia F. , Van Engen Kristin J.
Published: December 2020

In noisy settings or when listening to an unfamiliar talker or accent, it may be difficult to understand spoken language. This difficulty can result in reductions in speech intelligibility, but may also increase the effort necessary to process the speech. In the current study we used a dual-task paradigm and pupillometry to assess the cognitive costs associated with processing fully intelligible accented speech, predicting that participants would expend greater effort when processing nonnative-accented speech, and that this cost would be attenuated over time. Consistent with our hypothesis, the behavioral and physiological paradigms provided converging evidence that listeners expend greater effort when processing nonnative- relative to native-accented speech. We also observed an overall reduction in listening effort over the course of the experiment and found some evidence for greater perceptual adaptation to nonnative-accented speech. These results suggest that even when speech is fully intelligible, resolving deviations between the acoustic input and stored lexical representations incurs a processing cost, and adaptation may attenuate this cost.
Tongue root position during Mandarin Chinese stops
Authors: Ahn Suzy , Faytak Matthew , Kwon Harim
Published: December 2020

Tongue root advancement is reported to be an adjustment that facilitates phonetic voicing during stop closure (Westbury 1983). In a recent ultrasound study, Ahn (2018) reports that the tongue root is more advanced during the American English “voiced” stops than the “voiceless” stops even without actual phonetic voicing during “voiced” stops, suggesting that tongue root adjustment might not be tied to phonetic voicing, but rather implementation of a more abstract contrast. The current ultrasound study compares tongue root position during Mandarin Chinese voiceless unaspirated stops /p, t, k/ and voiceless aspirated stops /ph, th, kh/. These two Mandarin categories are acoustically similar to English “voiced” and “voiceless” stops in phrase-initial position. To confirm the role of tongue root advancement in English “voiced” stops, this study investigates eight native Mandarin speakers' phrase-initial stops. If the tongue root configurations during Mandarin aspirated and unaspirated stops are similar to each other, unlike those during English “voiced” and “voiceless” stops, English and Mandarin arguably have different types of contrast. On the other hand, if Mandarin shows comparable results to English, it further confirms that the tongue root advancement may have a different motivation than merely facilitating phonetic voicing.
Focusing on vertical larynx action dynamics
Authors: Oh Miran , Lee Yoonjeong
Published: December 2020

Previous studies have shown a positive correlation between fundamental frequency and vertical larynx position. Additionally, Lee (2018) suggests the possibility that there is roughly one vertical larynx movement (VLM) per Accentual Phrase (AP) in Seoul Korean. Building on these findings, this study investigates the effect of prosodic focus on vertical larynx movements. Target sentences designed to have roughly four APs (e.g., AP[JoohyunSUBJ] AP[shabby garden field] AP[six yardsOBJ] AP[soldDECL], presented in Korean) were used to elicit a focus condition with focus on the initial word of the object phrase (e.g., six). Results from five Seoul Korean speakers indicate that quantifiable vertical larynx movements observed with real-time MRI for each sentence range from 3 to 6 movements, with 4 movements per sentence being most frequent. Sentences under focus had more instances of VLM per sentence than those without focus. Additionally, the displacement magnitudes of the vertical larynx gestures decrease over time through the sentence. Lastly, focused sentences have significantly greater VL displacement around the region of focus than the control. These observations on vertical larynx actions have implications for prosodic planning, downdrift, and pitch resetting, and future work is examining how VLMs align and correlate with Accentual Phrases and fundamental frequency. [Work supported by NIH.]
Monitoring self-produced speech variability in native and learned languages
Authors: Bakst Sarah , Niziolek Caroline A.
Published: December 2020

Learning to produce new contrasts in a second language (L2) is challenging because learners have a less refined model of their new speech targets. Native speakers will correct subphonemic variability in their own speech, where greater variance triggers a greater degree of correction. Here we consider English (L1) speakers learning to produce front-rounded vowels as they acquire French or German. In one study, speakers uttered monosyllabic English and L2 words while simultaneously receiving different levels of masking noise to determine how access to auditory feedback information impacts speakers' ability to make online adjustments to self-produced speech. There was greater acoustic variability at both onset and midpoint of vowels in L2 than in L1, regardless of noise condition, consistent with a differential precision in executing motor programs in the two languages. In a second study, speakers received altered auditory feedback. On one-third of trials, the vowel formants of produced words were shifted up or down, creating the perception of an error. Compensation onset was earlier in L2, suggesting a stronger reliance on feedback than feedforward information in L2 production. In our ongoing studies, we investigate whether perceptual acuity in F2 may underlie these differences.
Second-language learners of French do not acquire habitual pitch values
Authors: Mason Alicia
Published: December 2020

Järvinen et al. (2013) find that native Finnish speakers have higher pitch in English, suggesting that habitual pitch can be learned during second language acquisition. The mean F0 of French may be higher than that of English (Pépiot 2014), and this study investigates whether native speakers of American English who are L2 learners of French show different mean F0 in their second language compared to their first, and whether this is affected by L2 proficiency. The study compared the average F0 in sentences spoken by 6 female L2 French speakers (3 high proficiency, 3 low proficiency) to their English F0, and to the F0 of 6 female L1 French speakers. The L2 French speakers' F0 showed no significant difference from their L1 English, but L1 French F0 was significantly higher than both English and L2 French (p < 0.01 in both cases). There was also no significant difference in F0 between the high-proficiency and low-proficiency L2 French speakers. This indicates that English-speaking L2 learners do not acquire the higher habitual pitch values of French, even as proficiency increases. A comparison with Järvinen et al's findings suggests that adaptation to L2 pitch may not be automatic and may vary by language.
Voice quality differences between American English speakers and Korean learners of English
Authors: Koo Hahn
Published: December 2020

Various features have been examined as markers of foreign accent including segment-level errors, deviation in subsegmental acoustic properties, as well as prosodic patterns such as intonation, rhythm, and speaking rate. Features that characterize voice quality may also be useful but they have been investigated less extensively in the literature. The present study explores the utility of voice quality features by analyzing and comparing speech samples from American English speakers and Korean learners of English documented in the Wildcat Corpus of Native- and Foreign-Accented English. Measures of jitter, shimmer, and harmonics-to-noise ratio (HNR) were extracted from vowels and compared between the two speaker groups. Overall, Korean learners produced English vowels with less jitter and shimmer as well as higher HNRs than English speakers. The pattern was consistently found in both scripted and unscripted speech and was more salient among male speakers than female speakers. Furthermore, the same trend, although weaker, was also found when the Korean and English speakers produced vowels in their respective L1s while reading comparable scripts. However, the Korean speakers showed more shimmer while reading scripts in Korean (L1) than English (L2).
Toward explainable convolutional neural network classifiers with acoustic-color sonar data
Authors: Williams David , España Aubrey
Published: December 2020

Convolutional neural networks (CNNs) have achieved state-of-the-art performance on a wide range of object classification tasks, including in the underwater domain. But one frequent criticism of the technique is that the features uncovered by the networks and used to make predictions are poorly understood. In this work, we develop CNNs whose predictions are explainable in the sense that they can be tied directly to physical properties of the objects under study. To achieve this, we consider limited-scope experiments in which the two classes of objects in a binary classification task differ by a single physical attribute. Importantly, to avoid overfitting and improve generalizability, the CNNs are designed with limited capacities and relatively small numbers of parameters compared to what is common in the literature. We then link the discriminatory clues discovered by the CNNs back to principled, understandable wave phenomena associated with the objects. The data used to conduct the experiments are measured low-frequency sonar data in the form of acoustic-color plots, which show target strength as a function of object aspect and frequency.
Categorization of broadband spectra of mesopelagic targets using model-generated training data
Authors: Cotter Emma D. , Lavery Andone C.
Published: December 2020

Recent studies using acoustic techniques suggest that mesopelagic biomass may be an order of magnitude higher than previously predicted by trawling, which has spurred increased interest in commercial exploitation of the mesopelagic zone. However, because of the limited understanding of species distributions in the mesopelagic, there is significant uncertainty surrounding these estimates. Here, we deploy a broadband (25–40 kHz) echosounder to mesopelagic depths to measure the target strengths of individual organisms. Automatic target detection and tracking are used to isolate individuals from the recorded data. Physics-based scattering models are then employed to generate a training data set with five broad classes: gas-bearing organisms that are observed above, below, or at their resonant peak, and fluid-like organisms that are observed either in the Rayleigh or Geometric scattering regimes. These training data are used to train a machine learning model to categorize the measured target spectra. The classification results agree well with human annotation and provide insight into both the distribution of organisms in the mesopelagic and the types of organisms that contribute most significantly to volume backscatter measured by shipboard echosounders.
R. Bruce Lindsay Award 2020: Julien Bonnel
Authors: Bonnel Julien
Published: December 2020

The R. Bruce Lindsay Award (formerly the Biennial Award) is presented in the Spring to a member of the Society who is under 35 years of age on 1 January of the year of the Award and who, during a period of two or more years immediately preceding the award, has been active in the affairs of the Society and has contributed substantially, through published papers, to the advancement of theoretical or applied acoustics, or both. The award was presented biennially until 1986. It is now an annual award.
In rememberance of William J. Cavanaugh
Authors: Tocci Gregory C.
Published: December 2020

William J. “Bill” Cavanaugh has left us a legacy of contributions to the practice of architectural acoustics and to the Acoustical Society of America. With a B. Arch. from MIT in 1951, and following active duty as a 1st Lieutenant in the U.S. Army Corps of Engineers, Bill embarked on a career in architecture at Polaroid Corporation. While walking through Harvard Square, by chance he met his former professor, Robert B. Newman who taught architectural acoustics at MIT. Bob, always on the lookout for bright staff, invited Bill to visit the newly formed firm of Bolt, Beranek and Newman (BBN). This was a turning point that brought Bill to the top of his new profession of consulting in architectural acoustics. Bill played a major part in bring acoustics, then often regarded as a part of physics, into day-to-day architectural design. This presentation will outline Bill's professional path, which very much follows the path of the growth of architectural acoustics.
Architectural acoustics, co-edited by Bill Cavanaugh
Authors: Jeon Jin Yong
Published: December 2020

Architectural acoustics, in addition to heat, light, and air, is an important component of architectural environment planning. Several monographs have been published in recent years. Among these, the best and most widely known is “Architectural Acoustics,” co-edited by William Cavanaugh (acoustician) and Joseph Wilkes (architect). It consists of a collection of chapters on various aspects of architectural acoustics, written by Bill and other experts. Bill's main contribution, by way of this book, “Architectural Acoustics,” to the field is the practical explanation of applicable architectural acoustic knowledge. In the second edition (copyrighted 1999) especially, various case studies involving a number of acoustic consultants in the second half of each chapter allow students to acquire sound designs through practical application and scientific verification. When this textbook was introduced and taught to masters and doctoral students in the field of acoustics, they learned that architectural acoustics was an extremely practical field of study. Most graduates who studied this book continued their studies and earned their Ph.D.s and are now teaching in universities or working as researchers in research institutes.
Outdoor concert monitoring, community noise, and the Cavanaugh Criterion
Authors: Hoover K. Anthony , Brooks Bennett M.
Published: December 2020

Sound from outdoor concerts and other sources can be challenging to measure, especially in the midst of ambient noises and environmental effects. It can be even more challenging to evaluate the data toward resolution of complaints and satisfaction for neighbors. In the mid 1980s through the 1990s, Bill Cavanaugh was deeply involved in important projects involving measurement and especially evaluation of outdoor concert sound levels, and he became a recognized leader in the field, consulting on amphitheater and outdoor venue sound and addressing community relations throughout the country. This presentation will review one of the most significant projects, then called Great Woods Center for the Performing Arts, now the Xfinity Center, in Mansfield, MA, an outdoor amphitheater with total 16 000 seats (now nearly 20 000), in which the Cavanaugh Criterion took shape, more in response to the many touring rock shows (and for which one of the first “green-yellow-red lights” was developed for the sound mixers' easy visual reference and better sound level control) than as the summer home of The Pittsburgh Symphony Orchestra. Recent application of the Cavanaugh Criterion for concert level evaluation of loud, powerful sound systems will also be reviewed, along with implications for application to a much wider range of possible outdoor and even indoor noise intrusions.
Bill Cavanaugh: Contributions to the understanding of room acoustics in performance venues through the Concert Hall Research Group
Authors: Glosemeyer Petrone Robin
Published: December 2020

A remarkable role model for acoustics consultants at any point in their career, Bill Cavanaugh was kind, humble, and always willing to share his successes and failures in hopes that we would all be better acousticians. In 1991, several acoustic consulting firms, including Cavanaugh Tocci Associates, came together to form the Concert Hall Research Group. They pooled experience and funds to support research and measurements in the interest of advancing the understanding of acoustics in concert halls. When the original work of collecting measurements from several halls was completed, Bill championed the idea of creating a Summer Institute to continue the advancement of knowledge. The Institute brought together acoustic consultants in performing arts, faculty and researchers in architectural acoustics, and college students studying or interested in architectural acoustic to foster conversations and honest sharing of knowledge in an informal and intimate setting.
Beaked whale foraging behavior during 12 kHz multibeam mapping survey off southern California coast
Authors: Kates Varghese Hilary S. , Miksis-Olds Jennifer , DiMarzio Nancy , Lowell Kim , Linder Ernst , Moretti David , Mayer Larry A.
Published: December 2020

To create appropriate marine mammal protection regulations, a better understanding of potential impacts of anthropogenic noise on marine mammals is needed. To contribute to the growing body of knowledge on this subject, echolocation clicks of foraging Cuvier's beaked whales were detected on the Southern California Antisubmarine Warfare Range (SOAR) hydrophones during 12 kHz multibeam echosounder (MBES) ocean mapping surveys in 2017 and 2019, and assembled into foraging events called group vocal periods (GVPs). Four GVP characteristics were analyzed Before, During, and After the MBES surveys to assess differences in foraging behavior with respect to the mapping activity. The number of GVP per hour increased During and After MBES surveys compared with Before. There were no other differences between non-MBES and MBES periods for the other characteristics: number of clicks per GVP, GVP duration, and click rate. These results indicate that the animals did not leave the range or stopforaging during MBES activity. [Funded by NOAA Grant No. NA15NOS4000200 through the UNH Joint Hydrographic Center.]
Lung ultrasound and high-resolution CT-scan of the chest for COVID-19 pneumonia
Authors: Smargiassi Andrea , Soldati Gino , Perrone Tiziano , Torri Elena , Mento Federico , Milardi Domenico , Del Giacomo Paola , De Matteis Giuseppe , Burzo Maria Livia , Larici Anna Rita , Pompili Maurizio , Demi Libertario , Inchingolo Riccardo
Published: December 2020

Lung ultrasound (LUS) has been reported as a useful tool to intercept lung peripheral changes (LPC) in COVID-19 pneumonia. Sixteen confirmed COVID-19 pneumonia patients underwent LUS using a standard sequence of scans in 14 landmarks. A score ranging from 0 to 3, according to Soldati's proposal, was reported for each landmark. High-resolution CT-scan of the chest (HRCT) was performed within 48 h prior to or after LUS. For each corresponding HRCT area, was reported a score (0 normal peripheral lung, 1 minimal LPC, 2 peripheral ground glass opacities (GGOs), 3 peripheral lung consolidations with or without GGOs) LUS showed sensitivity 92.1%, specificity 90%, PPV 96.8% to intercept LPC on HRCT (scores ≠ 0). Higher LUS scores (2–3), corresponding to worst changes, showed sensitivity 70.1%, specificity 84%, PPV 78.1% to intercept higher HTCT scores (2–3). The overall score, for both LUS and HRCT, over 14 landmarks, showed no significant differences (paired t-test p = 0.055). An overall score ≥24 was reported in five cases by LUS and 6 cases by HRCT. No significant differences also for patients either with more than three landmarks with score 3 or with 8 landmarks out of 14 with score 2–3 (p = 0.16). LUS showed good sensitivities and specificities compared to HRCT.
Numerical geometric acoustics
Authors: Potter Samuel F. , Cameron Maria , Duraiswami Ramani
Published: December 2020

We present a new approach to offline room acoustic modeling and simulation based on solving the eikonal equation, a nonlinear partial differential equation describing the arrival times of a high-frequency wavefront. We call the approach numerical geometric acoustics, since it combines some of the advantages of both numerical acoustics, where the acoustic wave equation or the Helmholtz equation are solved, and geometric acoustics, typically based on a variety of raytracing techniques. In our approach, reflection and diffraction effects are determined from boundary conditions connecting different eikonal problems generated by a recursion. This allows us to compute the multipath eikonal, a multivalued function parametrizing the arrival times of all acoustic rays propagating throughout a scene. Each branch of the multipath eikonal is computed by numerically solving the eikonal equation using a recently developed high-order semi-Lagrangian direct solver. This approach naturally encompasses spatially varying sound speeds. Our solver is compact and sufficiently high-order to allow us to transport the amplitude prefactor directly using paraxial raytracing. We discuss how to compute the acoustic parameter fields typical of precomputed room acoustic simulations used for virtual reality or games.
Using a linear microphone array to evaluate inhomogeneous sound-fields of recreated enclosures
Authors: Chertok Evan , Mathews Jonathan , Chabot Samuel , Braasch Jonas
Published: December 2020

Auditory Virtual Environments (AVE) typically recreate the sound at a specific listener position. Extended loudspeaker-based systems typically use the rich capabilities to enlarge the sweet spot, so a broader audience can experience the sound from the same virtual listener position. An alternative approach is taken with Rensselaer's Collaborative-Research Augmented Immersive Virtual Environment Laboratory (CRAIVE-Lab). Using 128 horizontally arranged loudspeakers, inhomogeneous sound fields are produced over a user area of 10 × 12 sqm, recreating the sound of acoustical enclosures using a ray-tracing method. A linear microphone array, consisting of 40 omnidirectional microphones, spaced 15 cm apart, is used to measure the fidelity of the reproduced inhomogeneous sound fields. This is accomplished by comparing the spatial room impulse responses measured in the CRAIVE-Lab to those generated synthetically (or computationally). The arrival times of direct sound and reflections are compared for both simulation methods. The analysis focuses on the spatial properties of the arriving wave fronts, including the direction of arrival and curvature, to determine the degree of accuracy to which the inhomogeneous properties of the sound field are reproduced. [Work supported by NSF #1909229.]
Subjective evaluation of carbon nanotube thermophones using spoken text
Authors: Bouman Troy , Barnard Andrew R.
Published: December 2020

Carbon nanotube (CNT) loudspeakers are modern thermoacoustic speakers. Their extreme light weight, lack of moving parts, and geometric flexibility provide the engineering community an exciting new tool in their sound generation toolbox. Prior to this study, no effort has been made to understand their subjective performance. All data in literature are objective metrics, e.g., sound pressure, sound power, total harmonic distortion, etc. This effort uses a hybrid paired comparison and modified rhyme test jury study to compare multiple CNT loudspeaker drive signal processing methods to traditional moving coil loudspeakers. The study scope was limited to single word spoke text.
Characterization of sand moisture profiles for improved atmospheric acoustic modeling
Authors: Cobb Faith A. , Wilson Nia , Vecchiotti Andrea , Turo Diego , Vignola Joseph , Ryan Teresa J.
Published: December 2020

This work presents an effort to understand and characterize the role moisture content plays in how sound interacts with sand on the beach. This work is part of a larger project developing a numerical model of long-range (~3 km) atmospheric acoustic propagation in littoral or riverine environments with a near-shore acoustic source and on-shore receivers. Previous experiments have studied the effects of moisture content of sand samples taken from various distances from the water's edge of a man-made lake with an artificial beach. This works seeks to perform the same studies in natural coastal areas by recording moisture content on site via a moisture probe at several depths, collecting samples to determine gravimetric water content of a bulk sample, and conducting testing with an impedance tube. Samples will be collected at various distances from the shoreline in order to inform a related effort that seeks to capture the acoustic characteristics of the sandy beach for use numerical modeling.
How much delay can you hear as a function of frequency? Towards the improved design of decorrelation algorithms
Authors: Canfield-Dafilou Elliot K. , Fujioka Takako
Published: December 2020

The extent to which the human auditory system can perceive phase information from incoming sounds has been much debated. While some research has suggested that humans are extremely sensitive to phase distortion, some believe that small amounts of phase distortion—up to about 20 ms—are almost inaudible. The latter assumption, in particular, is related to signal processing techniques such as decorrelation algorithms, which are widely used for artificially controlling the perceived diffuseness of the source information. The present study systematically examined the audibility threshold of the delay confined in a band of frequencies using an adaptive (2-down, 1-up) 2AFC procedure. We tested two types of audio sample: foreign-speech and instrumental music. For each signal, we introduced delays in one of five frequency regions (center frequencies: 250, 570, 1000, 2160, and 4050 Hz; critical bandwidths). Listeners could hear delays on the order of 5–10 ms in frequency bands lower than 1000 Hz, while in high-frequency bands, the delay threshold was much lower, around 1.5–5 ms. Moreover, thresholds were general lower for speech than music. While most listeners reported that the distortions were subtle, the results highlight the importance of frequency-dependent, content-specific design of the temporal limits in decorrelation algorithms.
Nonlinear modeling of tactical jet aircraft flyover noise
Authors: Ward Jacob A. , Gee Kent L. , Lympany Shane V. , Downing J. M.
Published: December 2020

Acoustic modeling of high-performance military aircraft is used to determine noise impacts and plan training operations. However, modeling accuracy to date has been limited because of nonlinear noise propagation, resulting in shock formation and greater high-frequency spectral levels. While prior work has investigated nonlinearity in noise propagation from static aircraft, this paper investigates the use of a nonlinear propagation algorithm based on the generalized Burgers equation to model noise propagation from F-35 flyovers. Waveforms recorded below the aircraft during a low-altitude flyover are used as the algorithm input and are propagated hundreds of meters. The sound pressure levels and spectra from the resulting waveforms are then compared with measured levels at the same distances. Using nonlinear modeling to predict the sound pressure levels significantly increases broadband spectral accuracy.
Estimating the noise floor of sonic boom metrics across the USA
Authors: Doebler William
Published: December 2020

NASA is building the X-59 Quiet Supersonic Technology aircraft to produce low noise sonic booms for a series of community noise surveys across the USA. Survey participants will rate their perception of the low booms from supersonic X-59 flyovers. Several noise metrics are proposed to quantify the noise dose: A-, B-, D-, E-weighted Sound Exposure Level, Stevens Perceived Level, and Indoor Sonic Boom Annoyance Predictor. Sparse measurements across the survey area will be used to estimate community noise exposure. The level of these low booms may be comparable to the ambient noise level in some locations, leading to uncertainty in noise exposure estimations. This uncertainty may necessitate increased reliance on sonic boom propagation predictions for exposure estimation. Low-boom signal to ambient noise ratio is one way to quantify uncertainty in measured sonic boom levels. An empirical relationship between A-weighted ambient level and sonic boom metric levels is used in conjunction with the National Park Service's L50 SPL map to estimate sonic boom metric ambient levels across the USA. The estimate of ambient sonic boom metric levels will aid in X-59 test planning and execution.