bluuebunny/crossref_metadata_2025 huggingface dataset:
Quasi-continuum theories of compressional wave propagation predicting amplitude-dependent anomalous frequency power law of attenuation
Authors: Pierce Allan D. , Holland Charles W.
Published: December 2020

A common assertion is that rational linear continuum mechanical models are incompatible with an attenuation exponent varying as first power of frequency at low frequencies, and that the attenuation in this limit always goes as frequency squared. Recently, the authors' attention was drawn to a paper [J. Geophys. Res. (1960)] by Leon Knopoff and Gordon MacDonald (K-M). They proposed a not-quite-linear one-dimensional wave equation that, with some math given in present paper, predicts attenuation proportional to frequency. An extension of the model to three dimensions begins with the Euler equation model that force on a fluid particle is proportional to negative of pressure gradient. The proportionality, however, depends on whether the particle is moving with or against the gradient. The increment is taken as a small constant times the “sign” function of the dot product of particle and pressure gradient vectors. With a perturbation technique similar to that of Krylov and Bogoliubov, one does indeed predict the linear frequency dependence. It is argued, however, that the abrupt discontinuity caused by the sign function is inconsistent with the notion of a rational linear continuum model. One can replace the sign function by a smooth function with desired asymptotic behavior, but the model then becomes nonlinear. This observation leads to the speculation that linear frequency dependence of attenuation is a nonlinear phenomenon that might not be observed if the amplitude is sufficiently low. [Work supported by ONR.]
Engineering an optical microphone for consumer electronics
Authors: Hall Neal A.
Published: December 2020

Between the years 2010–2015, a small start-up in Austin, TX was focused on commercializing an optical MEMS microphone to address high-volume consumer electronics applications. The motivation for the optical approach was to achieve a higher signal-to-noise ratio (SNR) than capacitive MEMS microphones. Similar to other commercial MEMS microphone offerings, the product was required to be small size, relatively low-cost, and surface-mountable. This presentation will focus on the challenges faced in engineering an optical microphone to meet these requirements. The particular approach used a diffractive optical element fabricated directly into the backplate of an otherwise conventional microphone die. Vertical-cavity surface emitting lasers (VCSELs) resided inside the die's etched cavity. Completed pilot-scale samples proved capable of demonstrating high SNR, but ultimately the company made a pivot to focus engineering and business-development resources on a similar product line—ground-motion sensors and seismometers. The company has been manufacturing and selling seismometers 2015–present.
Virtual acoustic environments for perception research
Authors: Vorlaender Michael
Published: December 2020

Human sound perception includes the ability to process auditory information from dynamic acoustic situations, which is an essential component for communication and orientation in everyday life. In contrast, standard psychoacoustic experiments don't include real-life situations.They include rather simple acoustic stimuli with nominally high reproducibility but low significance for situations in real life. The gap in research on auditory perception between the laboratory and real life can be closed now. Virtual Reality technology is a very powerful tool which connects real-time computer simulation with 3D devices for auditory-visual impressions. Virtual acoustics can incorporate any situational context and scene conditions with sources and sound propagation features in given environments. In consequence, ground-breaking research in auditory perception can be expected with higher degree of realism and with still high reproducibility. The presentation will highlight guidelines for creation of Virtual Acoustic Environments and examples for application in noise assessment, psychoacoustic research, and hearing diagnosis and rehabilitation.
Acoustical analysis of additively manufactured snare drums
Authors: Switzer Ethan , Jasinski Christopher M.
Published: December 2020

Additive manufacturing (3D printing) has seen tremendous growth over the past decade and is finding many fields of application, including in musical acoustics. Klapel Instruments has recently developed multiple snare drum prototypes using additive manufacturing production for the shell and rims of the drum. For the past two years, two pairs of undergraduates at the University of Hartford have worked with faculty to assess the acoustical properties of these drums, specifically focused on determining any acoustic differences caused by the new manufacturing technique and materials. Several traditionally manufactured drums along with the additively manufactured drums were tested structurally, performed on, audio recorded, and subjectively assessed. Modal, spectral, and subjective analysis along with a comparison between the drums created using additive manufacturing and the traditionally manufactured drums will be presented.
Talker depressive symptoms affect intelligibility of noise-adapted speech
Authors: Yi Hoyoung , Smiljanic Rajka
Published: December 2020

A critical aspect of communicative competence is talker's ability to adapt the clarity of their speech in response to the challenges of a particular communicative situation. Previous work showed that talkers with elevated depressive symptoms were less successful in producing listener-oriented intelligibility-enhancing clear speech. The present study investigated intelligibility of speech produced in response to environmental noise (noise-adapted speech, NAS) in talkers with high depressive (HD) and low depressive (LD) symptoms. Sentence intelligibility was examined in the presence of speech-shaped noise (SSN) and 1-talker (1T) competing speech. Results revealed that NAS increased intelligibility for both talker groups and in both maskers. NAS intelligibility benefit was smaller for HD talkers than LD talkers in the SSN condition. Acoustic analyses showed that NAS was characterized by a decreased speaking rate, increased F0 mean and range, and increased energy in the 1–3 kHz range. Talkers with HD symptoms however produced these modifications significantly less compared to talkers with LD symptoms. Results provide further evidence that elevated depressive symptoms impact speaking style adaptations in response to various communicative barriers leading to lower intelligibility. The results have the potential to aid in clinical decision making for individuals with depression.
Diverse environments and their impact on accentedness judgments
Authors: Kutlu Ethan , Tiv Mehrgol , Wulff Stefanie , Titone Debra
Published: December 2020

Research shows that listeners' perceived accentedness can be mediated by visual input (Babel & Russell, 2015; McGowan, 2015; Zheng & Samuel, 2017), and can change depending on their exposure to varied speech (Baese-Berk et al., 2013). Here, we tested the impact that visual input and linguistic diversity has on listeners' perceived accentedness judgments. Two experiments were conducted: one in Gainesville (USA) and one in Montreal (Canada). While these two locations were selected for their bilingual populations, Montreal has a more diverse linguistic landscape (Gullifer & Titone, 2019). Participants completed an accentedness judgment task where they were shown either a White or a South-Asian face while listening to sentences in American, British, and Indian English. They also completed a language background questionnaire, a social network questionnaire, and executive control tasks. In an ongoing study, results show that for Gainesville, participants' perceived accentedness of all three varieties increased when the visual input changed from a White face to a South-Asian face (F(2, 66) = 33.3, p < 0.001). The same effect was not observed for listeners in Montreal (F(2,23) = 0.664, p = 0.524). These preliminary findings suggest that exposure to both different accents and racial/ethnic categories on a regular basis could impact perceived accentedness judgements.
Speech intelligibility in primary school children: A systematic review
Authors: Murgia Silvia , Webster Jossemia , Cantor Cutiva Lady Catherine , Bottalico Pasquale
Published: December 2020

Good quality of voice signal and adequate classroom acoustics are important factors to guarantee an optimal teaching-learning process. This systematic review aims to characterize the relationship between intelligibility of the speech and room acoustics in primary schools based on the available evidence. Eligible studies were identified using two computerized databases: PubMed and Scopus. In total, 21 publications met our inclusion criteria: (1) subjects must have been from primary schools; (2) acoustic characterization of the classroom must been provided; (3) intelligibility tests must have been performed; and (4) articles written in English. After identifying the parameters and tests used to define the intelligibility of the speech, the subjective scores were analyzed in relationship with voice related parameters found in the articles (SNR and STI). Our results highlight the negative effect on intelligibility associated with the bad transmission of the speech and a poor acoustic of the classroom caused by long reverberation times and high background noise. Future research needs to include stronger study designs than “one-time survey” and analyze the results even in cases of acoustic interventions.
Acoustic characteristics of vowel reduction in advanced Spanish-English bilinguals
Authors: Conklin Jenna T. , Dmitrieva Olga , Jung Ye-Jee , Zhai Weiyi
Published: December 2020

Reduction of unstressed vowels is a well-known aspect of English phonology that is not present in Spanish, and the absence of such reduction contributes to accentedness in English for L1 Spanish speakers (Flege & Bohn, 1989). Previous studies have established that stress, coarticulatory effects of the previous consonant, and sociolinguistic factors can all lead to English vowel reduction in L1 and L2 speakers (Byers & Yavas, 2017). The current study investigates how lexical stress and sociolinguistic factors can affect vowel reduction in 10 American English monolinguals and 10 Spanish-English bilinguals from Colombia. A shadowing task provided acoustic measurements of formant frequencies for 60 target words in Spanish and English, encompassing five vowels from each language and two levels of stress. Factors such as language dominance, age of acquisition, linguistic attitudes, and length of residence were assessed through a questionnaire to examine their respective influences on the degree of vowel reduction shown by bilinguals relative to native monolinguals. Results address the degree of vowel reduction in L1 and L2 English and L1 Spanish, as impacted by linguistic and extra-linguistic factors.
Acoustic correlates of English clear speech produced by native Korean speakers
Authors: Jung Ye-Jee , Dmitrieva Olga
Published: December 2020

Monolingual clear speech is acoustically distinct from casual speech and can aid speech perception (Picheny et al., 1986; Smiljanic and Bradlow, 2005) but little is known about the acoustic properties of clear speech produced by non-native speakers. The current study aims to determine whether Korean non-native speakers of English modify their speech the same way native English speakers do when asked to speak clearly. A group of native Korean speakers residing in the United States (14 recorded to date) and a group of native speakers of English (9 recorded to date) were instructed to read a list of common English words (e.g., beat) using casual and clear speaking styles. The findings showed the effect of speaking style for every acoustic measurement: vowel duration, mean pitch, pitch range, positive and negative VOT, onset f0, and vowel space. With the exception of mean pitch, there were no significant interactions between group and speaking mode, indicating that Korean speakers implemented these acoustic parameters in L2 clear speech similarly to native speakers. Only for mean pitch, the degree of change associated with clear speech was greater for English speakers than for Korean speakers.
An examination of articulatory skill in monolinguals and multilinguals: A tongue twister experiment
Authors: Gilbert Crystal , Dugaillard Beckie , Krivoshaev Marianna , Spinu Laura
Published: December 2020

The main goal of this study is to determine whether articulatory differences exist between monolinguals (n = 19) and bilinguals (n = 21) through the analysis of tongue-twister production, following Goldrick & Blumstein (2006). The latter were divided into early bilinguals (consistent exposure to both of their languages before age 5, n = 8), mid bilinguals (exposure to L2 between 5 and 10 years, n = 5), late bilinguals (L2 exposure between 10 and 15 years, n = 3) and trilinguals (n = 5).The stimuli comprised 64 sequences that each contained four syllables (e.g., kif tif tif kif) and had to be repeated three times to a beat of a metronome (150 beats per minute). The recordings were rated by a trained listener, who gave a score of 1 for each accurately produced onset and coda consonant, and a score of 0 otherwise. In addition, a subset of the sounds produced were manually aligned in Praat to validate the raters' scoring and determine whether speakers also differed in less perceptible aspects of speech. The results show that while there are no overall differences in accuracy between the two groups (monolingual versus multilingual), bilinguals who were first exposed to their second language later in life (between 5 and 15) exhibit a statistically significant advantage in the articulation of tongue-twisters (Dugaillard & Spinu, 2019). Our findings underscore the importance of directly measuring bilingual language proficiency and incorporating this information to experimental design (DelMaschio & Abutalebi 2018, Sulpizio et al. 2019).
Gold Medal 2020: Judy R. Dubno
Authors: Dubno Judy R.
Published: December 2020

The Gold Medal is presented in the spring to a member of the Society, without age limitation, for contributions to acoustics. The first Gold Medal was presented in 1954 on the occasion of the Society's Twenty-Fifth Anniversary Celebration and biennially until 1981. It is now an annual award.
Architectural acoustics—From art to science, a tribute to Mr. William J. Cavanaugh
Authors: Koukounian Viken
Published: December 2020

The influence of Mr. William J. Cavanaugh's works, which span six decades, can be similarly summarized by the impact of his most recognized and pivotal publication—Speech Privacy in Buildings. The significance of this paper is appreciated in review of its place in history and following an understanding of the discoveries it permitted. Just as Mr. Cavanaugh balanced complex subjective and objective measures between various topics of study (acoustics, electronics, psychology, and physiology) in his novel work, he has empowered us to create and ensure a more favorable balance between art and science in architectural acoustics.
Interactions between whale-watching boats and humpback whale (Megaptera novaeangliae) singing cycle in the Colombian North Pacific soundscape
Authors: Rey-Baquero Maria P. , Huertas-Amaya Laura V. , Seger Kerri D. , Botero-Acosta Natalia , Perazio Christina E. , Luna-Acosta Andrea
Published: December 2020

Noise in marine ecosystems has increased significantly in the last decades. One of the most significant sources is vessel traffic. This affects animals that depend on sound to interact within their ecosystems, like interrupting communication which could lead to adaptive strategies to avoid the noise. We recorded the soundscape from 0 to 15 kHz in Morro Mico and Nuquí, Colombia, from 2018 and 2019—one of the most biodiverse locations in the world, and one that has never experienced high levels of vessel traffic and has no shipping lanes. Here, humpback whale Stock G migrates to their breeding ground. The species is well-known for its songs and social calls that facilitate biological and ecological processes. One process that could shape these vocalizations is noise generated by the artisanal fishing family boats. We explored correlations between the sound energy from the humpback whale song cycle, temporal features of the song structure, other biological acoustic signals, physical acoustic cycles, and the presence of small boats. These comparisons are important because there are no large vessels (requiring AIS) that transit closely to the study area. Therefore, we focused on soundscape cycles and acoustic responses of humpback whales from purely small vessel noise.
Long-lasting acoustic resonant signal associated with the turbidity current triggered by the 2003 Tokachi-oki earthquake
Authors: Iwase Ryoichi , Nomura Shun
Published: December 2020

Turbidity current triggered by the 2003 Tokachi-oki earthquake of M8 is observed at a multidisciplinary submarine cabled observatory deployed in southern Kuril subduction zone offshore of Hokkaido in Japan. The cabled observatory consists of a cable-end station, three ocean bottom seismometers (OBSs) and two pressure gauges (PGs). At each cable-end station and OBS, one hydrophone, whose sampling rate is 100 Hz, is also installed. The epicenter is located at 25 km west-northwest of the cable-end station. The arrival of the turbidity current is detected with both the electro-magnetic current meter and the acoustic Doppler current profiler (ADCP) at the cable-end station about 2 h after the earthquake occurred. In the waveform of the hydrophone at the cable-end station, relatively broadband signal is recognized to continue since the arrival of the turbidity current. About eight hours later, the peak frequency changes to 1 Hz and this resonant signal continues about four hours. Meanwhile, similar signals are not observed at OBS1 which is located 5 km northeast of the cable-end station. Although the source mechanism of the resonant signal is unknown to date, this indicates that the main body of the turbidity current passes the western side of the cable-end station.
A convolutional neural network applied to Arctic acoustic recordings to identify soundscape components
Authors: Ibrahim Malek , Sagers Jason D. , Ballard Megan S.
Published: December 2020

Underwater acoustic recordings often have contributions from anthropogenic, geophonic, and biophonic sources and deconstructing the sound field into constituent parts can be useful when characterizing the soundscape. This work focuses on the analysis of a yearlong acoustic measurement made on the Chukchi Shelf as part of the Canada Basin Acoustic Propagation Experiment (CANAPE). The data were recorded on a shallow-water array with horizontal and vertical apertures and span time periods including the open water season, marginal ice zone, and complete ice cover. A supervised convolutional neural network is trained on labeled spectra and demonstrates the ability to separate anthropogenic and biologic sources. Details of the model, labeling process, initial results, and lessons learned will be discussed in this talk. [Work sponsored by ONR.]
Identifying likely malignant lymph nodes in lung cancer through endobronchial ultrasound strain elastography and multi-modality imaging in a multi-center international prospective study
Authors: Verhoeven Roel L. , Trisolini Rocco , Leoncini Fausto , Candoli Piero , Bezzi Michela , Messi Alessandro , Krasnik Mark , de Korte Chris L. , Annema Jouke T. , van der Heijden Erik H.
Published: December 2020

To decide upon staging and concurrent treatment options in lung cancer, systematic endosonographic evaluation of lymph nodes as adjacent to the central airways and esophagus is of paramount importance. Based on imaging findings, repeated nodal sampling by endosonography guided needle aspiration is decided upon. Ultrasound strain elastography imaging might help identify likely malignant nodes, hypothesizing lower relative lymph node strain to be correlating to a higher chance of malignancy. Assessing if strain elastography can predict individual lymph node malignancy, also when further combined with available FDG-PET and nodal sizing information. A multicentric international prospective trial measuring patients with a lung cancer (suspicion) in standardized fashion (n = 5). Measurement outcomes are correlated to individual node follow-up outcome. A total of 525 lymph nodes (327 patients) are included. Receiver Operator Characteristic analysis of strain elastography measurements shows an area under the curve of 0.77. Specifying a mean nodal strain <115 (0–255) indicates malignancy with sensitivity 90%, specificity 43%, positive predictive value 60% and negative predictive value 82%. Combining available PET-CT and size information with strain elastography findings allows further risk stratification. Endobronchial ultrasound strain elastography helps predict lymph node malignancy in the work-up of lung cancer.
Usability of large animal models for lung ultrasound training and research
Authors: Wolfram Frank , Gutsche Holger , Braun Conny , Lesser Thomas G.
Published: December 2020

Lung ultrasound (LUS), particular under aspects of pneumonia and cardiopulmonary insufficiency, requires specialised sonographic expertise as well as knowledge of its specific features. Due to restricted access to clinical cases such as with viral pneumonia, alternatively large animal models can be used for education and research. Therefore this work summarizes approaches for inducing pathologic LUS features on large animals. These will be classified regarding presentation of A/B-Lines, White Lung (WLS), pleural irregularities, consolidations and are further discussed regrading their cardio-pulmonary stability. Most commonly ARDS inducing lung lavage, oleic acid injection and endobronchial saline administration were published. Dominantly B-lines, WLS were found in all such models. Albeit a specialized technique using endobronchial saline instillation (OLF) visualised all LUS features as typical present during viral pneumonia, such as consolidations with air/fluid bronchogram, pleural irregularities and their patchy distribution with areas of aerated lung. With regard to haemodynamic and oxygenation stability, OLF provides best haemodynamic stability and enables reusable usability of animals. Non-infective large animal models can be used for safe, reliable education of clinicians for teaching practical handling of lung ultrasound and could serve for research aspects regarding ultrasound imaging or safety.
Is lung ultrasound a predictor of worsening in Covid-19 patients?
Authors: Sabatini Umberto , Padovini Lucia , Lettieri Gianluca , Fiengo Anita , Gori Giulia , Lepore Federica , Garolfi Matteo , Perrone Tiziano
Published: December 2020

SARS-CoV-2 infection can generate different responses in patients, ranging from asymptomatic virus shedding to severe pneumonia associated with high mortality. To evaluate the potential prognostic role of a recently introduced Lung Ultrasound (LUS) protocol in this context, a cohort of 52 consecutive laboratory-confirmed COVID-19 patients underwent LUS examination upon the admission and before the discharge in an Internal Medicine ward. LUS score was derived from 14 body-landmarks (2 anterior, 2 lateral and 3 posterior per hemithorax). Specific scores were assigned depending on the sole presence of horizontal artifacts (0), the presence of isolated vertical artifact only (1), the evidence of sub-pleural consolidations (2), the presence of confluent vertical artifact and/or confluent/large consolidations (3). We then investigated the association between the total LUS score severity and worsening, defined as a combination of high flow oxygen support, intensive care unit admission, or 30-day mortality as primary endpoint. Preliminary results of the study show that worsening outcome was reached by 20 (39%) patients during the observation period; average LUS score was 20.4 (SD 8.4) and 29.2 (SD 7.3) in patients without and with worsening, respectively. At univariable analysis, the total LUS score at admission was associated with higher odds of worsening.
Simulations of room acoustics using fast multipole boundary element methods
Authors: Gumerov Nail , Duraiswami Ramani
Published: December 2020

Room impulse responses can be simulated using various methods that differ in their computational complexity and accuracy. While boundary element methods (BEM) potentially can provide accurate simulations in complex geometries including effects such as diffraction and absorption, their use is limited due to relatively large values of parameter kD (k is the wavenumber and D is the room diameter). The size of the mesh also grows as the square of this parameter. We show that the fast multipole (FMM) accelerated BEM realized on multicore workstations can handle problems for rooms of D ∼ 10 m for the frequency range up to ~5 kHz (kD ∼ 1000). For such problems, needing meshes with several million elements, stable and efficient methods for high frequency FMM are needed. We discuss these issues and demonstrate results of such computations both in frequency and time domains. In simple cases numerical solutions are compared with analytical solutions obtained by the method of images. For more complex cases including rooms of different shapes with baffles and openings two methods, the direct and indirect BEM, are studied and their performance discussed. [This work is supported by VisiSonics Corporation.]
Last call for the Wiki 4 Year of Sound 2020 campaign and the contributions from students
Authors: Morata Thais C.
Published: December 2020

The International Year of Sound (IYS 2020) is a global initiative to highlight the importance of sound in all aspects of life. Wikipedia is an important channel to share science information with the public. TheNational Institute for Occupational Safety and Health partnered withseveral acoustical societies in organizing an online event to facilitatethe improvement of Wikipedia content related to sound. The Wiki4YearOfSound2020 platform provided guidance on how to identify topics, improve, or translate existing articles. Throughout 2020, the Wikimedia outreach dashboard has been tracking progress, individual contributions, and their results, which reached tens of millions of views. A few educational programs tasked students to contribute high-quality content to Wikipedia as part of their class assignments. They used different dashboards to track progress. Students learned about the process and the value of translating science to the public. The goal of learning a topic well enough to be able to write in a style accessible to lay readers is challenging and requires more research than a traditional assignment. Finally, metrics made available by Wikipedia platforms were considered motivating and rewarding by instructors and students.
Acoustic conditions in occupied K–12 classrooms as measured over four continuous weekdays
Authors: Hintz Drake A. , Wang Lily M.
Published: December 2020

A recent study at the University of Nebraska–Lincoln involved capturing sound level data over four continuous weekdays in 55 K-12 classrooms during the 2017–2018 academic year. Equivalent sound levels in each classroom were logged every 10 seconds with an integration time of 10 s over two different weeks: once during heating season and once during cooling season. Among the results presented are the measured classroom reverberation times, average sound levels in each classroom when speech was occurring and when speech was not occurring, the percent of time that levels in each classroom exceeded certain values, and the daily variation of these metrics. The data gathered from this study are compared to data from 220 K-12 classrooms gathered in the 2015–2016 and 2016–2017 academic years. [Work supported by the United States Environmental Protection Agency Grant No. R835633.]
Emotions from musical notes? A psycho-acoustic exploration with Indian classical music
Authors: Sanyal Shankha , Banerjee Archi , Ghosh Dipak , Karmakar Samir
Published: December 2020

The most interesting feature of Indian Classical Music is the existence of Raagas. Each Raaga has its own peculiar ascending and descending movement called the Arohana and Avarohana. Even if two (or more) Raagas are made up of the same notes, the combinational varieties of notes evoke different emotions. In this work, we envisage to study how emotion perception in listeners' changes when there is an alteration of merely a single note in a pentatonic Raaga and also when a particular note(s) is replaced by its flat/sharp counterpart. 30-s recordings were done for two pair of Raagas which were chosen in a manner such that they are having difference in only one note keeping all others same. The fractal dimension of the auditory waveform provides a robust nonlinear quantitative parameter with which the two pair of audio clips can be compared. Also, the emotional appraisal from these two pairs were assessed on the basis of psychological listening tests as well as from cognitive response in the form of EEG experiments done on 10 participants. Interesting new results are obtained on how a trivial change in the note structure of a particular Raaga influences human emotion to a large extent.
Meta-learning for acoustic and music composing
Authors: Lisek Robert B.
Published: December 2020

We observe the success of artificial neural networks in simulating human performance on a number of tasks: such as image or sound recognition, natural language processing, etc. However, there are limits to state-of-the- art AI that separate it from human-like intelligence. Humans can learn a new skill without forgetting what they have already learned and they can improve their activity and gradually become better learners. Today's AI algorithms are limited in how much previous knowledge they are able to keep through each new training phase and how much they can reuse. In practice this means that it is necessary to build and adjust new algorithms to every new particular task. This is closer to a sophisticated data processing than to real intelligence. This is why research concerning generalisation are becoming increasingly important. A generalization in AI means that system can generate new compositions or find solutions for new tasks that are not present in the training corpus. Intelligent agent should have meta learning capabilities, should not just be able to memorize the solution to a fixed set of tasks during creating of stories, but learn how to generalize to new problems it encounters. The project proposes a solution for problems linked to organizing acoustic material and creation of new compositions based on meta-learning. Meta-Composer is a neural network equipped with the ability to combine acoustic materials and partial compositions in a flexible and combinatorial way to create a new consistent general composition.
A discussion on impulse noise exposure models in regard to small caliber firearm operation
Authors: Campbell Steven C. , Wall Alan T. , Rasband Reese D. , Murphy William J. , Mobley Frank S.
Published: December 2020

Impulse noise exposure is extremely prevalent in many military mission environments and, as such, it is critical that accurate hearing damage risk criteria be implemented. In 2017, the Air Force Research Laboratory (AFRL) conducted measurements at Quantico, Virginia on an outdoor shooting range in order to model exposure due to small firearm impulse noise. In this study, microphones were deployed across multiple arrays around an M16 rifle. Data were collected on the shooter for a selection of operational variables including shooter handedness, shooter height, and empty/occupied adjacent shooting lanes. A source model has been created through interpolation of data collected along a densely populated circular array surrounding the shooter at a radius of roughly three meters. By interpolating the array to achieve a fine angular resolution, the source model was then propagated via spherical spreading to generate a series of field point sound pressure levels. Via direct comparison, the simulated field points were validated against data collected from microphones outside of the source description array. Overall, this discussion provides a synopsis of previous work, future directions for research, and a discussion of the need for a unified, efficient exposure model for impulse noise. [Work supported by ONR.]
Comparative analyses far-field noise from GEM-63 solid rocket motor firings
Authors: Smith Jacob R. , Miller Clark O. , Bassett Michael S. , Rasband Reese D. , Anderson Mark C. , Mathews Logan T. , Gee Kent L.
Published: December 2020

Prior far-field noise measurements from static rocket firings [e.g., see B. O. Reichman et al., Proc. Mtgs. Acoust. 25, 045006 (2017)] in northern Utah have yielded valuable physical insights. This paper describes a comparative analysis of measurements made at three GEM-63 solid-fuel booster firings. Measurements were made at angles between 40 and 120 deg (relative to the plume direction) and distances of 985–1832 nozzle diameters. This paper discusses the three measurement setups, as well as other notable features relevant for data analysis, such as terrain and local meteorology. Spectral and statistical analyses are used to understand the frequency and temporal characteristics of the noise as a function of angle for all three firings.
The reinstatement of Working Group 41 (ANSI S12.66) guidelines for developing a community noise ordinance or regulation: First steps
Authors: Woolworth David s.
Published: December 2020

Working Group 41 of the ASA standards committee oversaw the development of ANSI-ASA S12.66 Guidelines for Developing a Community Noise Ordinance or Regulation, and has become active again after becoming dormant in 2013. The original goal of the working group was to create a model ordinance that could be tailored to a particular community by the local authorities, however over the 13+ years of the development effort it was evident that a “model” ordinance takes on the characteristics of a holy grail. A more holistic approach was adopted to examine community needs and resources, and considerations for judicial, executive, and technical limitations. Furthermore, the evolution of soundscape methods provide new tools for improving a community's involvement in the assessment of its needs. This paper will provide an overview of the working group's activity since Spring 2020.
Acoustic field design in microfluidic geometries via Huygens-Fresnel diffraction and deep neural networks
Authors: Collins David , Raymond Sam , Ai Ye , Willams John , O'Rorke Richard , Tayebi Mahnoush
Published: December 2020

Creating defined nonuniform acoustic fields, with particle capture locations beyond the grids and lines that are typically generated, has a range of applications in microfluidic systems. In this work, we use a unique interaction between polydimethylsiloxane (PDMS) channel geometries and a travelling substrate wave to explore the creation of nonuniform acoustic fields for microscale pattering. Surface acoustic waves (SAWs) are ideal for generating high-frequency, microscale wavelengths, though conventionally generate particle pattering via the interference between opposing SAW transducers, creating a standing SAW. Our recent work, however, has shown that patterning can alternatively be created using only a single travelling SAW and channel boundaries via diffractive effects, where fringe spacing is a function of the channel wall orientation. Unique to SAW, this creates a condition where the channel shape directly impacts the acoustic field that results, and therefore the possibility of designing acoustic fields by defining the channel geometry. To solve this inverse problem, we implement a machine-learning approach based on a Deep Neural Networks (DNN) that can define channel geometries resulting in desired acoustic fields. This submitted work will introduce the mechanisms via which this diffractive patterning occurs and the implementation of the DNN design process.
Airflow-acoustic interactions in speech production research
Authors: Shadle Christine H.
Published: December 2020

Speech production involves air traveling from a reservoir (the lungs) through various ducts (the bronchi and trachea, the vocal and nasal tracts), past various structures at which sounds can be generated by the flow of air. Some structures (e.g., the vocal folds or the tongue tip) can be positioned so as to self-oscillate, generating quasi-periodic sound; some (e.g., the lips or the tongue tip) can be positioned to create a constriction small enough to generate turbulence, and thus turbulence noise. These sounds excite the resonances of the tract. They can also interact, as when the sound generated by vocal fold vibration modulates the turbulent jet formed at a downstream constriction. It would seem to be straightforward to predict the sound that propagates through the tract and is radiated externally, except that the tract changes shape continually; the walls of the tract vary in compliance, from hard (e.g., teeth) to yielding (e.g., cheeks); and in spite of co-opting many types of medical imaging, it is very difficult to measure the interior shape of the tract accurately and without disturbing either the speech or the speaker. Some acousto-fluidic interactions that occur during speech, and the ways they have been modeled, are discussed.
Perception of vowels and consonants in cochlear implant users
Authors: Malinasky Melissa , Shafiro Valeriy , Moberly Aaron C. , Vasil Kara J.
Published: December 2020

Although cochlear implants (CI) improve speech intelligibility, they introduce distortions of the sensory input to the auditory system, and modify the transmission of acoustic cues. This study evaluated perception of consonants and vowels in experienced postlingual adult CI users. Twenty-five experienced CI users were tested with The Modified Rhyme Test (MRT) of consonant perception (word-initial and word-final) and a closed-set vowel test containing 12 vowels in the /hVd/ context. Overall consonant perception accuracy was 80%. No significant difference was observed in identification of word-initial or word-final consonants. There was significant variation in consonant accuracy in terms of place and manner, but not voicing. For place, alveolar consonants had the lowest accuracy. For manner, nasals were the least identifiable. Overall vowel identification accuracy was 76%. Accuracy was higher for front vowels than back vowels. The three most accurately identified vowels were (/i/), (/I/), and (/Ω/). The three least accurately identified vowels were (/a/), (/ɔ/), and (/u/). There was a considerable variation in consonant and vowel perception across CI users. The pattern or consonant and vowel confusions can inform CI programming and rehabilitation to improve speech perception.
Cross-frequency weights for loudness, pitch, and duration and their relation to speech recognition in normal-hearing and hearing-impaired listeners
Authors: Roverud Elin , Dubno Judy R. , Kidd Gerald
Published: December 2020

Many hearing-impaired (HI) listeners have uneven hearing loss across frequency, which could alter their weighting of cross-frequency information as compared to normal-hearing (NH) listeners. This has been suggested in previous psychophysical studies where listeners made loudness/level judgments of a multitone complex in which the level of each component was randomly varied trial to trial. The frequency components for which level variations correlated most strongly with subject responses indicate those given the most weight. However, the extent to which those weights are similar to weights for perception of pitch and duration—and how weights relate to the use of spectral information in speech—is not known. Here, the same NH and HI listeners performed weighting tasks involving the perception of loudness, pitch and duration. Recognition of low-pass filtered speech as a function of cutoff frequency was also measured. We tested the hypothesis that HI listeners would consistently downweight/underutilize frequency regions with more severe hearing loss, and that this would be apparent for weights across multiple stimulus dimensions and in speech recognition changes with bandwidth. Relationships among weights for NH and HI listeners for three stimulus features and bandwidth-related changes in speech recognition will be discussed. [Work supported by NIH NIDCD K01DC016627.]
Aging-related perceptual-grouping and attention-switching deficits in frequency discrimination amid task-irrelevant stimulus variability
Authors: Espinoza-Varas Blas
Published: December 2020

In elderly adults, failure to regroup auditory events and reallocate attention can defeat ignoring conflicting, task-irrelevant (CTI) information; specifically, ignoring CTI duration (ΔTc) or level (ΔLc) differences to focus on task-relevant frequency differences (ΔFr). Frequency Discrimination Thresholds (FDTs) were measured in 3I2AFC paradigms presenting a standard (Ts) followed by two comparisons (T1, T2); each interval presented tones either in isolation or trailed by captor tones. In young (YA) and in older (OA) adults, FDTs were measured without conflicting differences and amid ΔTc or ΔLc presented simultaneously with ΔFr or sequentially in the captor; FDT elevations relative to “without-conflict” FDTs indicated difficulty ignoring CTI differences. Because ΔLc disrupted the without-conflict discrimination strategy, amid ΔLc (but not amid ΔTc) discerning ΔFr required switching attention and regrouping auditory events: segregating Ts from T1, T2 with targets in isolation, or captors from targets in sequential conditions. Higher FDTs in OA than in YA obtained only if regrouping auditory events was mandatory. Facilitating segregation with increasing target-captor separation improved the FDTs of OA in all CTI difference conditions, but only amid ΔLc in YA. Regrouping auditory events and reallocating attention entailed shifting from bottom-up, automatic to top-down, schema-driven sequential grouping.
Evaluating the impact of external noise on psychoacoustic testing using the portable automated rapid test (PART) platform
Authors: Cherri Dana , Ozmeral Erol J. , Eddins David A.
Published: December 2020

The Portable Automated Rapid Test (PART) platform consists of a consumer electronics tablet and headphones with software for assessing auditory perception. One goal of PART is to expand our knowledge of the hearing profile of individuals. The standard PART battery includes psychophysical measures that span multiple auditory perceptual domains. To date, most of the psychophysical measures in PART have been validated in quiet laboratory settings. It is unknown whether or how ambient or external noise will impact threshold measures. Subjects completed the PART battery in quiet over headphones (65 dB SPL) and in the presence of external cafeteria noise through loudspeakers (59 dB SPL; consistent with literature on waiting area noise). In separate conditions, we mixed pink noise through the headphones as a means to potentially mitigate the impacts of external noise (50 dB SPL; maximum level that did not impact thresholds). Threshold measures were collected from 10 young listeners with normal hearing. Results indicate that neither the pink noise nor the cafeteria noise affected average thresholds on any of the tasks relative to the quiet condition. These data support the use of PART in relatively uncontrolled listening environments like clinic waiting rooms or at home. [Work supported by NIH R01DC015051.]
Challenges in the development of a fully autonomous auditory training and testing system
Authors: Brungart Douglas S. , Barrett Mary , Russell Shoshannah , Archambault-Léger Véronique , Holtzman Rebecca R. , Dirks Coral , Clavier Odile
Published: December 2020

The Computerized Auditory Training (CAT) pilot study is a feasibility study utilizing android tablets to remotely administer auditory training and conduct auditory assessments. The goal of the study is to examine user acceptability and the effectiveness of different types of auditory training modules. The CAT protocol administers a predetermined regimen of auditory training sessions interleaved with structured auditory assessments that are designed to track subject progress over time. Participants choose the type of training they want to perform from options that include both interactive game-based training modules and more conventional modules based on standard adaptive psychophysical procedures. Timers are utilized to limit the amount of training that can be performed in a single session. Here, we will discuss some of the challenges in the development of the system and the strategies employed to address them, including (a) the ability to maintain control over the level and frequency response of the acoustic signal presented to the listener; (b) the ability to monitor the background noise level during training and testing; (c) the ability to remotely track participant progress and provide incremental payments for subject participation; and (d) the ability to remotely access and analyze participant data. The views expressed here are those of the author and do not reflect the official policy of the Department of Army, Department of Defense, or U.S. Government.
TeamViewer software can facilitate remote data collection for studies initially designed for in-lab testing
Authors: Cohen Julie I. , Gordon-Salant Sandra , Brungart Douglas S.
Published: December 2020

During speech perception experiments, well-controlled and calibrated stimuli are presented to the listener, whose task is often to repeat the speech stimulus heard. Researchers typically score the listener's responses in real-time, and may also record the verbal responses for scoring verification. Due to the COVID-19 pandemic, data collection on an ongoing speech perception study was halted. Our goal was to resume data collection with exactly the same stimuli and procedures while maintaining the safety of the participants and examiner. To that end, TeamViewer (v.15.7.7) software was used to administer the experiment using remote access to a research laptop. All study materials, including a laptop with the programmed experiment (MATLAB 2011) and high quality headphones were delivered to the participant's home. Stimuli developed for the experiment were recorded remotely by talkers using a microphone and recorder. A custom MATLAB script was run from the experimental laptop to facilitate collection of speech perception data. Both portions of the experiment required the use of the TeamViewer software, to instruct the participant in the experimental protocol and permit oversight of data collection. Specific methods used to conduct stimulus recordings and collect data will be discussed.
Telepractice: Acoustic characteristics of the patient, parent, and provider speech
Authors: Kondaurova Maria V. , Donaldson Cheryl W. , Zheng Qi , Lowman Joneen , Bush Matthew L.
Published: December 2020

How does the use of telepractice during speech therapy affect the acoustic characteristics of the speech-language pathologist (SLP), the child and her parent speech compared to those in conventional in-person intervention? This study examined prosodic and lexical characteristics in an SLP, mothers and their children with cochlear implants (CI) (n = 7, mean age 59 months, range 43–81 months) productions during one 30-min in-person session and one sequential tele-session, order counterbalanced. Mean pitch (Hz), pitch range (Hz), utterance duration (s), speech rate (syll/utterance duration) and mean length of utterance (MLU) were measured in 30 utterances produced by each child, mother and the SLP in the in-person and tele-sessions. Preliminary analysis indicates that the child, her mother and the SLP produced similar mean pitch across both sessions, however, their pitch range was more expanded during the in-person than the tele- session. The SLP and the mothers' utterance durations were longer during the in-person than the tele- session. The child, her mother and the SLP produced faster speech rate and a higher MLU during in-person than the tele- session. Results suggest that acoustic and lexical (MLU) characteristics of the child, the caregiver and the provider speech are affected by telepractice.