bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance of a ground-based microphone system for outdoor sound measurements
Authors: Anderson Mark C. , Gee Kent L. , Novakovich Daniel J. , Mathews Logan T. , Jones Zachary T.
Published: December 2020

This paper discusses analyses of a ground-based outdoor microphone system designed to be weather-robust. This system employs an inverted half-inch microphone placed one-quarter inch above a thin plastic convex circular plate and enclosed in a dome windscreen. The current iteration of the “compact outdoor unit for ground-based acoustical recordings,” nicknamed COUGARxt, is an improvement over its predecessor because of its thicker windscreen and its thinner plate made of a harder plastic material. One system characterization is anechoic chamber testing, where a sound source was placed at different elevation and azimuthal angles relative to the COUGARxt system to understand performance differences. Acoustical effects of plate orientation and the thicker windscreen are discussed. Another analysis consists of outdoor measurements in a windy but otherwise quiet environment. The COUGARxt system shows improved wind-noise rejection between 3 and 100 Hz, which could be important for improved detection of infrasound sources, including sonic booms and long-range launch vehicle noise.
Education and healthcare: A look at ASA/ANSI S12.60 and ASA/ANSI S12.70
Authors: Good Kenneth W.
Published: December 2020

Two of the most important spaces for society are where we learn and where we heal. This session will take a brief review of the ASA/ANSI S12.60 standards for education spaces and ASA/ANSI S12.70 speech privacy in healthcare standard. The discussion also will include architectural trends and what updates the respective working groups are addressing.
Experimental assessment and modeling of acoustophoretic particle trajectories
Authors: Barnkob Rune
Published: December 2020

The field of acoustofluidics, the employment of acoustic forces in microfluidic systems, is receiving growing attention for use in biomedical applications due to its use for label-free and non-invasive separation and manipulation of cells and other biological particles. The field is young but has over the last decade undergone an important development towards clinical and industrial application, in particular due to an improved understanding of the underlying fundamental physical aspects. Here, theoretical modeling and experimental assessment of acoustophoretic particle trajectories have played an essential role, e.g., for the measurement of the in situ pressure amplitudes and resonance quality factors or for the understanding of the critical particle size for which the acoustophoretic particle motion is dominated by the acoustic streaming drag or the primary acoustic radiation force. These phenomena are typically of complex three-dimensional character and can only be fully understood through three-dimensional quantification such as through three-dimensional tracking of the acoustophoretic particle motion, e.g., via the General Defocusing Particle Tracking method. The importance of three-dimensional particle tracking will be demonstrated by application to the acoustophoretic particle motion in soft-walled polymer chips driven by surface acoustic waves as well as in hard-walled square glass capillaries driven by bulk piezo transducers.
Vocal emotion identification and quality of life in adult cochlear implant users
Authors: Strong Stephanie , Moberly Aaron C. , Vasil Kara J. , Shafiro Valeriy
Published: December 2020

Self-report quality of life questionnaires, such as the Nijmegen Cochlear Implant Questionnaire (NCIQ), are increasingly paired with speech intelligibility tasks to assess cochlear implant (CI) outcomes. Previous research [Luo et al., J. Acoust. Soc. Am. 144, EL429–EL435 (2018)] found that vocal emotion identification was positively correlated with the six NCIQ subdomains. The current study attempted to replicate and extend previous findings, using similar procedures with a new sample of CI listeners. Eighteen postlingually implanted adults were randomly presented with 10 semantically neutral sentences spoken by one female talker expressing one of five emotions (happy, sad, angry, scared, and neutral). In addition to NCIQ, participants completed SSQ12 and HHIE. The overall emotion identification accuracy was 66% correct. No significant associations were found between emotion identification and any NCIQ or HHIE subscales. There were significant positive correlations between emotion identification and SSQ12 (spatial subscale and total score). The present NCIQ results diverged from the previous findings, suggesting at best a tenuous relationship between emotion identification quality-of-life measures. However, the reduced emotion identification scores of CI users suggest that these tasks may have clinical utility in CI assessment and rehabilitation.
Enhancing the temporal fine structure with the temporal limits encoder for cochlear implants: Effects on pitch discrimination
Authors: Zhou Huali , Yu Guangzheng , Meng Qinglin
Published: December 2020

To enhance the mostly discarded temporal fine structure in modern cochlear implant (CI) strategies, a temporal-limits-encoder (TLE) strategy was proposed by downshifting the high-frequency-band-limited signal to a low-frequency-temporal-pitch-limits range of CIs [Meng et al., J. Acoust. Soc. Am.(2016)]. This study investigates pitch perception with a TLE strategy compared with a standard advanced combinational encoder (ACE) strategy. Seven CI subjects were tested in a complex-tone-pitch discrimination task measuring the fundamental frequency difference limens (F0DLs) at four reference F0s (250, 313, 1000, and 1063 Hz, which are the center and upper cross-over frequencies of two bands). Results show that (1) the CI listeners generally had lower F0DLs with TLE than with ACE (group mean F0DL benefits of TLE over ACE of 5.0, 9.6, 0.5 and 4.3 percentage points at the four reference F0s, respectively) and (2) the two strategies had comparable sentence recognition performance in both quiet and noisy conditions. These findings suggest that the slowly varying TFS introduced by TLE is feasible in pitch discrimination for CI listeners and is not significantly detrimental to sentence recognition. This discrimination advantage can be explained by larger differences in the temporal fluctuations on individual channels with TLE than with ACE.
Launching the first “Clarity” Machine Learning Challenge to revolutionise hearing device processing
Authors: Akeroyd Michael A. , Barker Jon P. , Cox Trevor J. , Culling John , Graetzer Simone , Naylor Graham , Porter Eszter , Viveros Muñoz Rhoddy
Published: December 2020

Recent advances in machine learning raise the prospect of radically improving how hearing devices deal with speech in noise and so improve many aspects of health and well-being for an aging population. In many other aspects of speech processing, rapid transformations have been enabled by a research tradition of “open challenges.” Thus, to catalyse such progress for hearing devices we launch this month (Dec 2020) a new machine-learning challenge series, “Clarity” (claritychallenge.org) The first challenge will focus on sentences from single talkers in a moderately reverberant environment with typical background noises for the home. We will supply all these recordings (including a new multi-talker database of speech sentences) together with generative models to combine them in sufficient quantities for machine learning. We will also supply a comprehensive set of “baseline,” modular models of hearing impairment, hearing aids, speech intelligibility and speech quality. The tasks for challenge entrants is then to build on these, developing new and improved approaches for hearing device signal processing so that the intelligibility of these sentences is maximised for hearing-impaired listeners.
Automated pure tone audiometry with true wireless stereos earbuds
Authors: Guo Zhenyu , Wang Xianren , Zhou Huali , Lu Yigang , Yu Guangzheng , Meng Qinglin
Published: December 2020

Amounts of automated pure tone audiometer applications have been developed for personal terminals in recent years. However, most of them require specifically designed headphones, which are usually expensive and not accessible to most people. The commercially available true wireless stereos earbuds (e.g., Honor Flypods and Apple Airpods) got a prevalence in recent years. In this study, Flypods were used in a specifically developed automated audiometer whose algorithms and calibrations were modified for wireless earphones. The calibration was established by using both a KEMAR manikin and a loudness comparison method. Twenty subjects with mild to moderate hearing loss were recruited in a clinical verification experiment. The average deviation of automated audiometry was 3.1 dB, when referring to the thresholds measured by a conventional manual audiometer with a pair of TDH 39 headphones. Most (63.2%) of the deviations were under 5 dB. The sensitivity and specificity across frequencies from 125 to 8000 Hz were 95.4% and 62.6%, respectively. The results demonstrate that it is practical to utilize this sort of affordable wireless earphones for preliminary hearing level screening.
Speech data collection at a distance: Comparing the reliability of acoustic cues across homemade recordings
Authors: Zhang Cong , Jepson Kathleen , Lohfink Georg , Arvaniti Amalia
Published: December 2020

Speech production data collection has been significantly impacted by COVID-19 restrictions. Sound-treated recording spaces and high-quality recording devices are inaccessible, and face-to-face interactions are limited. We investigated alternative recording methods that produce data suitable for phonetic analysis, and are accessible to people in their homes. We examined simultaneous recordings of pure tones at seven frequencies (50 Hz, every 100 Hz between 100 Hz and 600 Hz), and three repetitions of the primary cardinal vowels elicited from five trained speakers. Recordings were made using the ZOOM meeting application and non-lossy format smartphone applications (Awesome Voice Recorder, Recorder), comparing these with Zoom H6N reference recordings. F0, F1-5, and duration based on manual segmentation were measured. F0 is highly correlated between the three devices for vowels and tones. Lower formants are also significantly correlated though not as robustly. The upper formants showed more variation as reported in the literature. Both phone and ZOOM performed better for vowels than tones. Phone segmentation generated reliable duration values differing from H6N segmentation by ∼18 ms. However, irregular waveforms and filtering algorithm artefacts caused considerable differences for ZOOM (∼119 ms). Our preliminary study suggests phone recordings are a viable option for some phonetic studies (e.g., prosody). Future analysis of natural speech data will prove insightful.
Nonlinear acoustic-structure interaction in high intensity focused ultrasound power transfer systems
Authors: Bhargava Aarushi , Meesala Vamsi C. , Shahab Shima
Published: December 2020

Ultrasound power transfer (UPT) has emerged as one of the most promising technique to wirelessly transfer power. The mechanism of UPT involves vibration-induced generation of acoustic waves from a piezoelectric transmitter which propagate in a medium to interact with a piezoelectric receiver, and generate vibrations-induced electrical response in the receiver. In this work, a novel technique of using a high intensity focused ultrasound (HIFU) is proposed to enhance the power transfer efficiency as compared to current UPT systems. HIFU concentrates the entire transmitted energy at a focal spot where the piezoelectric receiver is placed, thus dramatically reducing the input energy required, as compared to unfocused UPT systems. The physics of the HIFU-UPT system consists of a nonlinear acoustic wave propagating in a medium to induce a nonlinear structural response in the receiver. Implementing the HIFU-UPT phenomena in an experimentally validated finite-element based model shows that the nonlinear acoustic field can induce disproportionately high responses in a receiver if the harmonics in the acoustic wave coincide with the structural resonant frequencies of the receiver. This research aims to provide a comprehensive framework for designing UPT systems operating in nonlinear acoustic fields with a finite size receiver.
The effect of hearing aid signal processing on speech intelligibility in a realistic virtual sound environment
Authors: Mansour Naim , Marschall Marton , May Tobias , Westermann Adam , Dau Torsten
Published: December 2020

To develop hearing aids (HA) that benefit users in real-world acoustic conditions, it may be helpful to evaluate HA algorithms psychoacoustically, in controlled yet realistic laboratory settings. However, typical outcome measures like speech intelligibility (SI) are commonly obtained using rather artificial acoustic stimuli. This study investigated the effect of HA signal processing on SI in a more ecologically valid way, using a spatialized version of the Danish Hearing In Noise Test inside a loudspeaker-based virtual sound environment (VSE). The VSE employed spatial recordings of two real-world sound scenarios and quadraphonic speech-shaped noise (SSN) as distinct masker stimuli with spatialized target speech. Unaided performance was compared with results obtained in two master HA configurations: a basic setup consisting of dynamic range compression only and a setup including beamforming as well. Overall, speech reception thresholds (SRTs) were significantly higher in the conditions with real-world noise maskers compared to the artificial SSN masker. HA performance depended strongly on input signal-to-noise ratio (SNR) and was most effective at negative SNRs. The HA setup including beamforming only revealed benefits for the SSN masker. This study underscores the importance of evaluating SI and HAs at realistic SNRs, allowing for better prediction of real-life HA benefit.
Initial weakening in Mixtecan languages
Authors: DiCanio Christian , Sharp Jared
Published: December 2020

Prosodic boundaries influence patterns of consonantal strengthening and weakening across languages (Fougeron and Keating, 1997; Kakadelis, 2018; Katz and Fricke, 2018; Keating et al., 2003; White et al., 2020). Onset obstruents/nasals in prosodically prominent positions are lengthened and produced with greater contact between active and passive articulators (Fougeron and Keating, 1997; Fletcher, 2010; Keating et al., 2003; Lavoie, 2001). Typically, articulatory strengthening occurs in utterance-initial and word-initial position while weakening/reduction occurs in word-medial position (Katz and Fricke, 2018). We provide phonetic evidence that certain obstruents in word-medial, pre-tonic position are both lengthened and strengthened in Itunyoso Triqui, an indigenous language of Mexico, while word-initial obstruents are often shorter and reduced. We examined 67 min (8933 segments) from a spontaneous speech corpus produced by nine native speakers; and measured duration, voicing lenition, and spirantization. Onset consonants were lengthened slightly in stem-final (stressed) syllables but shortened elsewhere. For sonorant consonants, no utterance-initial lengthening was observed. These findings agree with previous work on a related Mixtecan language—Yoloxóchitl Mixtec (DiCanio et al., submitted)—and pose unique challenges for views hypothesizing that consonantal strengthening is either (a) universal or (b) serves to enhance word-level parsing (Katz and Fricke, 2018; White et al., 2020).
An acoustic study of the contrast between clear and plain speaking style for Mandarin
Authors: Tupper Paul , Leung Keith , Wang Yue , Jongman Allard , Sereno Joan
Published: December 2020

This study examines the acoustic characteristics of clear and plain conversational productions of Mandarin tones. Twenty-one native Mandarin speakers were asked to produce a selection of Mandarin words in both plain and clear speaking styles. Several tokens were gathered for each of the four tones giving a total 2045 productions. Seven critical tonal cues were computed for each production: fundamental frequency (F0) mean, slope, curvature (computed by a parabolic fit to the tone contours), duration, mean intensity, location of maximum intensity, and a binary variable coding whether the production involved creaky voice. A linear mixed-effects regression model was used to explore how these cues changed with respect to the clear versus plain distinction, with fixed effects being speaking style and tone and the only random effect being speaker. The strongest effects detected were that duration and mean intensity increased in clear speech across speakers and tones. Other cues did not show consistent changes with speaking style. An additional finding was that, for contour tones, speakers accomplished the increase in duration by stretching out the tone contours in time while not changing the F0 range. These results are discussed in terms of universal versus tone-specific clear speech modifications.
Complex interplay of lexical stress and focus prominence in Tohono O'odham
Authors: Kim Daejin , Cruz Robert
Published: December 2020

This paper explores how the linguistic contrast (focus prominence) is realized with the rhythmic and timing pattern, evidenced in the typologically rare and complex plural noun reduplication (CVC → CVCVC; e.g., ban “a coyote” versus baban “coyotes”) in Tohono O'odham (TO). Our preliminary result of two native speakers of TO indicates that the greater focus effects (lexically and morphologically contrastive focus) are realized with the higher f0 at the first CV sequence and the lower f0 at the second CV sequence, strengthening the language-specific strong-weak (SW) stress pattern. However, no focus effect was found on the durational properties. Also, no significant morphologically contrastive focus effect, contrasting singular and plural forms of the target words, was found on both f0 and durational properties. Our finding implies that the realization of prosodic and phonological elements in Tohono O'odham is also conditioned with fine-grained phonetic details. We also discuss the future possibility of the complex phonetics-prosody interplay of the language.
Inversion in rough surface scattering via the frequency-difference autoproduct
Authors: Joslyn Nicholas J. , Dowling David R.
Published: December 2020

The forward scattering of acoustic waves, with wavenumber k, from a rough surface is a well-known problem in underwater acoustics. A random rough surface, statistically characterized by its root-mean-square roughness h and its correlation length L, exponentially reduces reflected field coherence as kh increases. The frequency-difference autoproduct is a nonlinear mathematical construction that recovers field coherence in rough surface scattering by down shifting recorded signal frequencies, thereby minimizing apparent surface roughness. Salient features of frequency-difference-autoproduct forward-scattering results, including the dependence on both h and L, are shown. Further, this presentation describes the unique capability afforded by the frequency-difference autoproduct to approach the inverse problem in a rough surface scattering environment. In particular, inference of a random rough surface's root-mean-square height and correlation length is accomplished via autoproduct-based signal processing methods. The work implements an isotropic surface roughness profile corresponding to in-band roughness values of 1.25 < kh < 3.5. Using the same scattered signals, conventional in-band inversion techniques are compared to the results obtained via the frequency-difference autoproduct. Experimental results from a laboratory water tank may be discussed as well. [Work supported byONR.]
Mid-frequency propagation and reverberation time series ina deep ice-covered ocean: Modeling and data analysis
Authors: Ivakin Anatoliy N. , Williams Kevin L.
Published: December 2020

Mid-frequency (3.5 kHz) pulses (5 pings, 5 s-long, one per minute) were radiated by an omnidirectional source of opportunity in a deep (3 km) Arctic ocean at 30m depth under ice during the ICEX14 experiment, ALAS component [Williams et al., IEEE-JOE 43, 145–159 (2018)]. Data analysis and modeling results are presented for normalized (re source level) acoustic intensityreceived by an omnidirectional hydrophone located at a 719 m distance from and the same depth as the source. Received time series showed a clear direct blast signal followed by an about 30 s-long reverberation coda. Modeling of the under-ice propagation shows that magnitude of the direct signal is strongly affected by presence of a weak near-surface (within 50 m depths) acoustic channel and by reflectivity of the ice, controlled by its physical properties and acoustical parameters, particularly the ice layer thickness. Analysis of the reverberation coda shows effects of reflections and scattering from rough and/or heterogeneous bottom, as well as reflectivity of the ice layer. Some other effects that may be caused by variability of the sound speed profile and absorption in water are considered as well. Possibilities of inversions for water column, bottom and ice parameters based on this and similar experiments are discussed. [Work supported by ONR.]
Bill Cavanaugh–Reflections from abroad
Authors: Soker Joseph , Haedo Alberto
Published: December 2020

Bill Cavanaugh was enormously influential and well-known, with many international friends and colleagues. This presentation willoffer some insights and stories about Bill as a friend and colleague to a couple of us, from Israel and Argentina. He encouraged our participation in professional societies, including the Acoustical Society of America (ASA) and the National Council of Acoustical Consultants (NCAC) which has become International, he offered much wisdom and advice, and he was a dear friend.
Bill Cavanaugh: The gold standard for acoustical consultants!
Authors: Siebein Gary W. , Siebein Keely M.
Published: December 2020

William (Bill) J. Cavanaugh was cited by the Acoustical Society for “practical applications in building design and education in architectural acoustics and service to the Society” when he received the Gold Medal. Bill set the “gold standard” for all people as well as for acoustical consultants for several generations. You can tell that he was trained as an Architect because of the joy that he found in working on challenging projects, the beauty of his hand sketches and solutions that resulted from his innovative and creative thinking and his desire to work with people through challenges. The field of architectural acoustics is perhaps more architectural because of Bill's contributions. His spearheading of his notable book with Joe Wilkes Architectural Acoustics: Principles and Practice was a major contribution to the field. His research, teaching and consulting work grew in parallel with the new discipline of architectural acoustics that he was shaping with his work. He was fundamental in beginning the Robert B. Newman Medal in architectural acoustics which has positively impacted the careers of many students. Above all, he was a man dedicated to family, faith and community in a way that serves as a shining example to us all.
Anthropogenic underwater sound emissions and other ecological effects on the marine environment
Authors: Hughes Derke R.
Published: December 2020

This presentation provides an overview of U. S. Navy and academia sponsored research to monitor, measure, model and mitigate the effects of active sonar sound transmissions on the health and well-being of marine mammals. Sound in the ocean has received considerable attention in the last several decades. Such intensive interest is in the sustainability and conservation of marine resources in ocean environments. Marine mammals in particular are sensitive to anthropogenic sounds. To capture the frequency-dependent nature of these sound effects on marine species, auditory computed weighting functions emphasize frequencies where a particular species is most susceptible to noise exposure. Researchers within academia and government continue development of functions like these and other metrics to characterize marine mammal responses to anthropogenic sound in the ocean. Underwater acousticians, marine biologists, oceanographers, engineers and computer scientists combine efforts to provide common standards of measuring and characterizing the anthropogenic sound effects on marine species. Further, computerized sonar equation models are used to: (1) provide standards of measuring and characterizing anthropogenic sound affecting various mammal species, and (2) determine metrics to guide policy makers' decisions in determining best practices for balancing marine environmental protection with national defense obligations.
Detecting and localizing lung nodules by leveraging ultrasound multiple scattering
Authors: Roshankhah Roshan , Blackwell John , Ali Mir , Masuodi Behrooz , Egan Thomas M. , Muller Marie
Published: December 2020

Although CT is widely used for detecting pulmonary nodules inside the parenchyma, the accurate real time lesion detection during video-assisted surgical procedures using ultrasound-based techniques is very attractive to improve to resection margins. Imaging the parenchyma using conventional B-mode is impossible due to multiple scattering in lung. However, the multiple scattering contribution of ultrasonic waves can be exploited, to detect the regions inside the lung with no scatterers. Nodules are homogeneous regions with relatively uniform properties compared to the healthy heterogeneous parenchyma containing millions of alveoli. We took advantage of this and developed an algorithm to extract multiple scattering contributions inside the highly scattering lung to localize pulmonary nodules. Inter-element response matrices were acquired using translated sections of a linear array transducer to semi-locally investigate the backscattered field. Extracting the multiple-scattering contribution using singular value decomposition and combining it with a depression detection algorithm allowed to detect regions with less multiple scattering, associated with the nodules. We validated this method in lung phantoms and demonstrated their feasibility in ex vivo pig and dog lungs containing artificial Vaseline nodules. We evaluated 7 lung blocks (4 pigs, 3 dogs) with multiple nodules and have localized all nodules in the last 4 lungs.
Ultrasound waves propagation in aerated inhomogeneous media
Authors: Peschiera Emanuele , RIgolin Thomas , Mento Federico , Demi Libertario
Published: December 2020

Lung ultrasound (LUS) has become a widely adopted diagnostic method for several lung diseases, recently also for COVID-19. However, LUS is mainly based on the presence of imaging artifacts, such as B-lines. These artifacts correlate with several pathologies, but their genesis is still partly unknown. Therefore, a study which focuses on the factors affecting these artifacts is carried out, numerically simulating through the MATLAB toolbox k-Wave ultrasound propagation inside the lungs. Since the main hypothesis behind the generation of B-lines is based on multiple scattering phenomena occurring once acoustic channels open at the lung surface, it becomes important to study the impact of changing alveoli diameter and spacing. In fact, these parameters influence waves capabilities of propagating beyond the pleural-line and how the different contributions add up. The tested numerical domain is of size 4 cm × 1.6 cm, the investigated frequencies vary from 1 to 5 MHz, the diameters and spacing range from 100 to 400 μm and from 20 to100 μm, respectively. Results show the strong and entangled relation between the wavelength, the domain geometries and artifact visualization, allowing to better understand propagation in such a complex medium and opening several possibilities for future studies.
Simulating lung ultrasound imaging with body wall and alveolar anatomy
Authors: Soulioti Danai , Ostras Oleksii , Pinton Gianmarco
Published: December 2020

The majority of diagnostic ultrasound imaging is performed in regions with modest variations in the impedance (∼5%) which results in relatively small reflections from soft tissue interfaces. Lung ultrasound imaging is unique because it attempts to image an air-filled organ which is almost totally reflective. Thus the interpretation of lung ultrasound imaging depends on the analysis of the scattering, multiple scattering, and reverberation physics occurring at or near the complex soft-tissue/air interfaces. Even though this physics determines the image content, its relationship to the image, and its dependence on the diseased states of the lung are poorly understood. To establish a link between body wall and lung anatomy and the resulting ultrasound image we use a custom ultrasound simulation tool (Fullwave) in conjunction with acoustical maps of human body derived from the visible human project and maps of alveolar structure derived from lung histology. The experimentally validated simulations of ultrasound propagation includes attenuation, dispersion, nonlinearity, and the multiple interactions of sound at soft tissue/air interfaces. Ultrasound images are then simulated based on the first principles of propagation and reflection. We demonstrate that key features of clinical lung ultrasound imaging such as A- and B-lines can be observed. Anatomical and diagnostically relevant parameters, such as fluid percentage, alevolar density, are pleural thickness are varied to determine their effect on the final image.
Graduate acoustics education in the Cockrell School of Engineering at The University of Texas at Austin
Authors: Ballard Megan S. , Haberman Michael R. , Hall Neal A. , Hamilton Mark F. , Isakson Marcia , Porter Tyrone M. , Wilson Preston S.
Published: December 2020

While graduate study in acoustics takes place in several colleges and schools at The University of Texas at Austin (UT Austin), including Communication, Fine Arts, Geosciences, and Natural Sciences, this poster focuses on the acoustics program in Engineering. The core of this program resides in the Departments of Mechanical Engineering (ME) and Electrical and Computer Engineering (ECE). Acoustics faculty in each department supervise graduate students in both departments. One undergraduate and nine graduate acoustics courses are taught in ME and ECE. Instructors for these courses include staff at Applied Research Laboratories at UT Austin, where many of the graduate students have research assistantships. The undergraduate course, taught every fall, begins with basic physical acoustics and proceeds to draw examples from different areas of engineering acoustics. Three of the graduate courses are taught every year: a two-course sequence on physical acoustics, and a transducers course. The remaining six graduate acoustics courses, taught in alternate years, are on nonlinear acoustics, underwater acoustics, ultrasonics, architectural acoustics, wave phenomena, and acoustic metamaterials. An acoustics seminar is held most Fridays during the long semesters, averaging over ten per semester since 1984. The ME and ECE departments both offer Ph.D. qualifying exams in acoustics.
Tonal-timbral based bicoherence analysis of a viola da gamba suite for wolf tone characterization
Authors: Scott Nicholas V. , Jensen Sarah , Maday Edward
Published: December 2020

Wolf tonal and timbral modulation of excited strings on viola da gambas are an annoying occurrence having a serious impact on the overall delivery of a musical composition. Fourier spectral analysis of this phenomenon obfuscates deep understanding through its exclusive focus on Gaussianity and disregard of frequency and quadratic phase coupling. With the desire to exhume nonlinear acoustical structure, an experimental study was conducted to investigate the efficacy of bicoherence analysis in understanding wolf tonal and timbral structure existing in two viola da gambas of similar dimension but different construction tuned to A 415 Hz. Bicoherence analysis of digitally recorded notes played on the C string and sampled at 44.1 kHz revealed significant but medium bicoherence spectral levels in variable patterns surpassing 50%. These levels appeared on unique notes for each instrument, D# and F, and were independent of amplitude providing evidence of non-Gaussian wolf tone warbling which was not always clearly audible. This was possibly due to phase coupling at very low and high frequencies lying on the perimeter of the audible music range. Results have implications for improved understanding of the relationship between viola da gamba construction and acoustical characteristics.
Acoustic noise measurements during neonatal magnetic resonance scans
Authors: Kurdila Hannah , Zaidi Tayeb , Zhang Ting , Rajan Sunder , Maruvada Subha
Published: December 2020

The magnetic resonance (MR) scan is a standard means to image the human body that produces significant sound pressure levels. Steps have been taken to explore and mitigate this threat for the adult patient, but now, it is becoming standard practice to use MR scanners on neonates, who are believed to be more sensitive than adults to loud sounds. We present (1) a survey of the neonatal MR practices of hospitals in the DC area, (2) details of the sound levels produced during neonatal scan protocols, and (3) an appraisal of the threat level to the neonatal patient based on our findings and the current literature surrounding neonatal hearing.
On a fast hearing test method according to sub-band listening frequency
Authors: Bae Seonggeon , bae myungjin
Published: December 2020

Modern man is exposed to an environment where hearing is susceptible. Hearing generally worsens in the higher frequencies as the body ages. However, in the case of noise-induced hearing loss, there is a possibility of partial hearing loss. The pure sound hearing test listens to the pure tone of each frequency for 250–8 kHz sound, which is used in everyday conversation, and grasps the response of the sound, but it takes a lot of time to measure the hearing. In this paper, we propose a new method for screening hearing in the sub-band area without being examined in the hospital. We extended the pure audio hearing measurement method by voice sub-band and examined the noise-induced hearing loss by band. The sound is divided into sub-bands, and the number of sounds heard is applied. The sound source heard at this time is nine pure tones with the frequency increased by Mel scale from 500 to 8000 Hz. If the number of sounds perceived in the sound source heard first is greater than the number of sounds perceived in the sound source heard later, the person with partial hearing loss is determined. In 12 trials, one of them was identified as suspected partial hearing impairment. By using this method, you can conveniently and easily determine whether you are hearing impaired to maintain a healthy life.
Optimizing the spray characteristics of an ultrasonic droplet generator with continuously variable operating frequency
Authors: Shan Li , Meacham John M.
Published: December 2020

Ultrasonic spraying is utilized in a diversity of industrial processes and biomedical applications, including nanomaterial synthesis and inhalation drug delivery. Ultrasonic droplet generators transfer energy into bulk liquids using acoustic waves to break the free liquid surface into extremely fine microdroplets. We have previously reported an approach that combines ultrasonic actuation, resonant operation, and acoustic wave focusing for efficient spraying of liquids (e.g., low surface tension fuels, high viscosity inks, and suspensions of biological cells). Microfabricated devices comprised a piezoelectric transducer, sample reservoir, and an array of acoustic horn structures with microscale orifices. Orifice size dictated droplet size, and the fixed reservoir geometry restricted operation to specific device resonant frequencies. Here, we incorporate a continuously variable reservoir height that enables dynamic adjustment of operating parameters (e.g., to improve spray efficiency or to tune the droplet size in real-time). Finite element analysis is used to predict the harmonic response of the system for a range of reservoir heights from 0.5 to 3 mm (corresponding to operating frequencies from 0.5 to 2.5 MHz). Spray quality is optimized regarding uniformity and stability of active nozzles for arrays with 10, 20, and 40 μm orifices, and model results are used to explain observed behaviors.
Examining phonetic trends in the speech of transgender YouTubers
Authors: Ramsey Trevor M.
Published: December 2020

In LGBTQ research, transgender speech is understudied compared to gay and lesbian speech. Fundamental frequency (F0) and vowel space have both shown as useful in determining speaker gender (Simpson, 2009; Gaudio, 1994). Sibilants are also used to determine gender and sexuality (Zimman, 2017; Munson, 2007). This analysis of transgender YouTubers examines F0, vowel space, and sibilants and how their speech aligns with cisgender speakers. Videos of seven transgender YouTubers were transcribed and force-aligned. Measurements were taken comparing speakers within each group and with cisgender speakers. All transgender speakers produced F0 commensurate with cisgender speakers. Vowel space was plotted, showing transwomen produce an expanded vowel space when compared to transmen. Direct comparison to cisgender speakers was not undertaken. Differences in sibilant duration between groups was not borne out in the data. Spectral mean was also measured and transwomen showed ranges similar to ciswomen. Transmen were more variable in their production of sibilants. This study shows that transgender speakers produce speech that mostly aligns with cisgender speakers for the sounds measured. Though not representative of all trans people, these speakers show gendered speech is not simply physiological and further study may aid in efforts toward greater transgender equality.
That /s/ tiene tumbao: Investigating acoustic correlates of femme queerness in Bilingual Miami
Authors: Mendoza Christopher M.
Published: December 2020

Sociophonetic work on the production of /s/ has shown an indexical link between feminine gender expression and higher centers of gravity and negative spectral skew, corresponding to a fronted articulation of [s + ] (Hazenberg, 2012; Podesva and Van Hofwegen, 2014). In this paper, I explore how Latinx identity and multilingualism complicate our understandings of [s + ] as indicative of femme-coded identities. At the same time, this work also adds to the literature on the use of [s + ] in communities of drag queens (Calder, 2019) by demonstrating how it gets mediated by the bilingual Latinx body during the process of feminine drag visual transformation. I examine the production of /s/ amongst 3 Cuban-American drag queens in sociolinguistic interviews conducted in English and Spanish while participants are transforming into their drag personae. The interviews were recorded and the center of gravity and skewness were calculated for each extracted token of /s/ presented during the exchanges using an automated Praat script (Boersma and Weenink, 2019). Preliminary results on center of gravity measurements indicate that /s/ is consistently produced by Miami drag queens with a fronted articulation in English, while Spanish productions have a higher range of variability.
Vowel characteristics of Black speakers' English in Southern Louisiana
Authors: Shport Irina
Published: December 2020

Although variation in English has been documented in Louisiana, little sociophonetic research has been conducted with Black Louisianans. In this study, acoustic characteristics of eleven vowels were examined in three groups of Black Louisianans (residents of New Orleans, New Iberia, and relocators from New Orleans to New Iberia after Hurricane Katrina) and a group of White New Iberians, five middle-aged participants per group. 240 productions of each vowel were elicited in a word-reading task. Vowel duration and formant measurements at 20%, 50%, and 80% into the vowel were examined in mixed model regression analyses. Results showed that Black speakers did not participate in /u, o/ fronting associated with White speech. All of them exhibited the African American Vowel Shift (except for the /I/ vowel): their /a/ was fronted and lowered, /æ/ was fronted and raised, and /ε/ was raised. Some variation in vowel production existed among Black speaker groups as well; for example, New Orleanians had in-gliding /i, u/ and less diphthongized /o/ as compared to New Iberians. The non-homogeneity of Black speech and maintenance of phonetic variants of the native community by relocators is discussed in the context of the U.S. South.
Categorization of U.S. regional dialects and race from speech
Authors: Wolff Emerson V. , Bent Tessa , Lentz Jennifer
Published: December 2020

Listeners extract a range of indexical information about speakers from the acoustic speech signal. Listeners show moderate to high accuracy with the two dimensions investigated here—race and regional dialect—with generally higher accuracy for race than regional dialect. In this project, both race and regional dialect identification from the same talkers were tested when the dimensions were varied orthogonally. In a forced-choice categorization task, listeners were presented with 144 unique audio clips of monolingual English talkers from Midland, New York City, and Southern dialect regions who were either Asian, Black, or white. Stimuli were presented to listeners in two separate, counter-balanced testing blocks (i.e., one for race and one for regional dialect). Results showed higher accuracy for race identification than regional dialect, with white Midland talkers most accurately identified by race and Southern Black talkers most accurately identified by dialect. Both tasks showed significant interactions between the two indexical dimensions. The results suggest that an irrelevant indexical dimension can impact perception of the relevant indexical dimension. Further, the composite of a listener's identity and their experiences with people of various ethnicities, racial and dialect groups can shape their perception and response biases. [Work supported by Indiana University Hutton Honors College.]
The differential contribution of segmental and suprasegmental aspects of a foreign English accent to negative perceptions by native and non-native speakers
Authors: La Franceschina Anna Maria
Published: December 2020

Foreign accents are often stereotyped as a “broken” form of the language, triggering negative reactions in native listeners—a phenomenon attributed to a general reduction in cognitive fluency. This study aims to determine the relative contributions of segmental and suprasegmental features to the perception of foreign-accented speech. Sentences in English were recorded by native speakers of Russian, Italian, and English (the latter as a control group). The recordings were manipulated to form 3 sets: naturally produced, intonation only (i.e., filtered in Praat with a low-pass Hann filter), and segmental only (i.e., foreign pronunciation was preserved in terms of consonants and vowels, but the intonation resembled that of English). Each utterance was presented to native (n = 26) and non-native English speakers (n = 32) residing in NYC and rated on several dimensions on a 1-5 Likert scale. The results support previous findings, indicating that foreign accents cause speakers to be perceived more negatively even in strongly multicultural environments. We discuss the effects of segmental/suprasegmental information in native and non-native perception and a number of language-specific patterns. This study adds to the body of work on the mechanisms underlying listeners' reactions to foreign-accented speech.
Foreign language talker identification training does not generalize to new talkers
Authors: Lee Jayden J. , Tin Jessica A. , Perrachione Tyler K.
Published: December 2020

Listeners identify talkers less accurately in a foreign language than their native language, but it remains unclear whether this is due to lack of experience identifying foreign-language talkers or whether linguistic processing reveals additional talker-specific information in speech. Here, we investigated whether two types of training improved the ability to learn to identify foreign-language talkers. Participants completed four days of talker identification training in Mandarin, an unfamiliar foreign language. Participants were assigned to either the “same-voices” condition, in which they trained on the same five voices during days 1–3, or the “different-voices” condition, in which they learned a new set of five voices on each day. Both groups learned five new voices on day 4. Talker identification accuracy improved across days 1–3 for the same-voices condition, but not for those in the different-voices condition. However, talker identification accuracy on day 4 did not differ from the day 1 baseline for either group. These results suggest that knowledge about foreign-language talkers is limited to the training set, and that, without specific linguistic knowledge, training on foreign-language talkers does not generalize to improved ability to learn to identify new foreign-language talkers.
Visual feedback and self-monitoring in speech learning via hand movement
Authors: Liu Yadong , Saha Pramit , Gick Bryan
Published: December 2020

While human speech learning largely relies on perceiving sounds [Brainard and Doupe, Nat. Rev. Neurosci. 1(1), 31–40 (2000)], being able to see articulators also contributes to learning speech sounds [Gick et al. (2008), Phonology Second Language Acquisition 36, 315–328 (2000)]. However, seeing hands is not necessarily helpful for learning new hand movements [Emmorey et al., J. Memory Lang., 61(3), 398–411 (2009)]. This study investigates whether being able to see a hand, acting as a speech articulator, facilitates the learning of speech production via hand movements. Two groups of participants under different visual feedback conditions were asked to produce different vowel sequences via a system that maps hand movements to F1 and F2 of English vowels [Liu et al., Can. Acoust. 48(1) (2020)]. The results suggest that visual feedback contributes to the speed of speech learning and reaching vowel targets more accurately via hand movements. This study provides insight on the importance of visual feedback in monitoring speech, and supports the view that monitoring speech articulators visually can accelerate speech learning.
Visualization, detection and classification of Risso's and Pacific white-sided dolphins using an empirical mode decomposition-based process
Authors: Al-Badrawi Mahdi H. , Liang Yue , Kirsch Nicholas J. , Seger Kerri D.
Published: December 2020

Risso's and Pacific white-sided dolphins occupy similar habitats and have been acoustically documented in northward habitat expansion above the Aleutian archipelago. Therefore, being able to differentiate between the two, either more easily during manual analysis or through automation, is important to track their distribution and to estimate their population densities. In our previous work, a semi-blind detection and classification (SDC) process based on Empirical Mode Decomposition (EMD) showed promise for detecting and clustering vocalizations and mooring noises from several sources in the Bering Sea. In this work, we incorporated other decomposition methods into this process, such as Variational Mode Decomposition (VMD), to visualize peak and notch patterns in pulsed signals. The proposed process is being tested on four datasets that vary by location, water depth, and recording instrumentation to quantify its robustness and identify and overcome its limitations. A case study to determine the usability of EMD/ VMD spectrograms in marine mammal click and buzz classification was performed by comparing peak and notch patterns of these two dolphin species. We will present the pros and cons of incorporating VMD spectrograms into the previously published EMD SDC process.