bluuebunny/crossref_metadata_2025 huggingface dataset:
Tongue root position in Hijazi arabic voiceless emphatic and non-emphatic coronal consonants
Authors: Alfaifi Abdullah H. , Cavar Malgorzata E. , Lulich Steven M.
Published: December 2020

The longstanding interest in Arabic emphatic consonants stems in part from their articulatory variability across dialects. In different dialects, emphatics are variously described as pharyngealized, uvularized, velarized, or even glottalized consonants. This pilot study analyzes ultrasound images of the voiceless coronal emphatic consonants (traditionally transcribed as pharyngealized /tʕ/ and /sʕ/), and compares them with the corresponding non-emphatics (/t/ and /s/), and with the uvular /q/ in identical vocalic environments. We also examine coarticulatory interactions between emphatic consonants and adjacent vowels. Data from two native speakers of Hijazi Arabic showed more retracted tongue root in emphatics compared to non-emphatics. The emphatics are different from uvulars, in that the tongue dorsum is not raised toward the uvular place of articulation. Non-emphatic coronals are potentially velarized, or even palatalized, especially in the context of a front vowel. Short vowels (/a/, /i/, /u/) were more affected by emphasis in the adjacent consonant than the long vowels (/a:/, /i:/, /u:/), with more retracted tongue root position in the context of emphatic consonants. The high back vowels (/u/, /u:/) were less affected by emphasis than the other vowels.
Articulatory strategies and their acoustic consequences: Investigating tongue retraction and lip protrusion tradeoffs in talkers with amyotrophic lateral sclerosis
Authors: Johnson Reilly , Kim Nadia , Tjaden Kris , Mefferd Antje
Published: December 2020

Observations of tradeoffs between lip protrusion and tongue retraction during productions of /u/ suggest that typical talkers can vary their articulatory strategies without affecting their acoustic output. In this study we tested the hypothesis that talkers with dysarthria due to amyotrophic lateral sclerosis (ALS) may take advantage of such trading relations and exaggerate lip protrusion to preserve speech acoustics in the presence of impaired tongue retraction. 14 talkers with mild to moderate dysarthria due to ALS (8 females, 6 males) and 14 age- and sex-matched controls produced “Tomorrow Mia may buy you toys again” five times at their habitual rate. Speech kinematics were recorded using electromagnetic articulography. Tongue retraction and lip protrusion were measured by calculating the displacement of the posterior tongue and upper lip sensors in the anterior-posterior dimension of the midsagittal plane during the production of “buy you.” F2 transition extent was measured by calculating the change in F2 (F2 maximum-minimum) during “you.” Group means of kinematic and acoustic variables were compared to determine between-group differences in articulatory and acoustic performance. Linear regressions were used to determine the contribution of each articulator as well as the combined effect of both articulators to F2 transition extent within each group.
Low-latency localization in the spherical harmonics domain using an iterative search method
Authors: Mathews Jonathan , Braasch Jonas
Published: December 2020

Higher-order ambisonic microphones have attained considerable interest for their ability to allow spherical harmonic decomposition of soundfields. In taking advantage of this property, myriad methods have been produced for directional filtering and subsequent analysis, as well as localization and tracking of soundfields. This study introduces a technique to estimate direction of arrival of an acoustic signal by generating a set of spatial filters corresponding to randomly chosen orientations over the sphere, then iteratively reducing the region for orientation selection based on the maximum power obtained from the filter response. This method is distinct from existing mapping- and vector-based methods in that it produces accurate, low-latencyresults in the presence of moderate reverberation. Results obtained using both simulated and experimental data demonstrate viability of this technique for localization in large, reverberant spaces as well as accurate source identification under real-time conditions. [Work supported by NSF grants #1631674 and #1909229, and the RPI Cognitive and Immersive Systems Laboratory.]
Improving the performance of the Bartlett method for single-snapshot direction-of-arrival (DOA) estimation using signal processing on graphs (SPG)
Authors: Alcantara Eldridge , Abadi Shima , Atlas Les
Published: December 2020

Single-snapshot direction-of-arrival (DOA) estimation has long been studied under the framework of conventional signal processing. The most well-studied method estimates DOA from the power spectrum of data that is assumed to lie on a fixed grid in which samples are uniformly spaced, an algorithm known as the conventional Bartlett method. By using a fixed grid, the linear weights used to calculate power are fixed and the method's estimation performance, which can be measured by RMSE versus SNR, is fixed as well. Is it possible improve the Bartlett method's performance by appropriately adjusting these linear weights? In this presentation we show that we can if we apply principles and tools from Signal Processing on Graphs (SPG) so that data now lies on a variable grid known as a graph. We first replicate the system used for the conventional Bartlett method using SPG and then extend the system so it can work on other grids (or graphs). From this SPG-based system, we then show there exist graph structures that will produce linear weights in which RMSE, for certain SNRs, are lower than the conventional Bartlett method. Finally, we validate these results further through simulations.
Jiri Tichy's contributions to acoustics and noise control engineering
Authors: Maling George C.
Published: December 2020

In the mid 1960s, my interest in reverberation rooms for the determination of sound power led me to get to know Jiri Tichy because he had similar interests in the field. At IBM, we had a good relationship with Professor Tichy and others at Penn State in making recommendations for student projects and following through with funding. He served as president of the Institute of Noise Control Engineering of the USA (INCE-USA) and was very active in presenting at the INTER-NOISE and NOISE-CON series of international and national conferences on noise control engineering. He played a major role in bringing INTER-NOISE to Prague in 2004 Four of us, William Lang, Matt Nobile, Jiri Tichy, and me also collaborated on the handbook article on determination of sound power of noise sources in the book Noise and Vibration Control Engineering edited by Leo Beranek and Istvan Ver. While his main interests were architectural acoustics and active control, he made many contributions to noise control engineering.
Spectral interleaving by singing humpback whales: Signs of sonar
Authors: Mercado Eduardo
Published: December 2020

Singing humpback whales produce a wide variety of tonal and broadband units within their songs, usually organized into patterned sequences. Here, an extensive database of songs made available through Google's Pattern Radio website was analyzed to test the hypothesis that singers produce consecutive units in ways that minimize overlapping spectral content. Consistent with earlier analyses, singers maintained spectral separation across units within most repeating patterns (phrases and subphrases). Additionally, singers preserved the continuity of concentrated spectral energy, as well as the timing of units, as they cycled through different themes. Within songs, singers alternated between producing units that generated persistent reverberant tails tightly focused within narrow frequency bands and more impulsive, broadband units. By spectrally interleaving units, singing humpback whales can potentially avoid overlap between units that could interfere with auditory reception of the signals. By producing signals with broadband and narrowband elements that are spectrally and temporally segregated, singers may also maximize the distances at which they can detect and localize targets using echoes from those signals.
Deteclic: A multi-method detector of sperm whale's click
Authors: Cassiano Fabio , Drémeau Angélique , Samaran Flore , Quidu Isabelle
Published: December 2020

In the French EEZ of Crozet and Kerguelen Islands, longline fishing is heavily impacted by the depredation of sperm whale, with significant socio-economic implication and ecological impact. Until now, only visual observations of the surface have been used to monitor this phenomenon. Their limitations have raised the need to extend the methods of investigation. Thus, an autonomous acoustic recorder was attached directly to the longline and several hours of recording were collected, disqualifying de facto manual annotation of the data. To overcome this difficulty, we developed an automatic detector, based on five simple methods from the literature: intercorrelation with a reference signal, a Teager-Kaiser energy operator convolved with a Gabor function, spectrogram analysis, kurtosis-based statistical detection and analysis of the Daubechies 15 wavelet-transform. The different methods runs independently with a click-length analysis window allowing a click-by-click detection, and then performs a vote to limit the false alarm rate. Our tool performance is assessed on a dataset where 2450 clicks have been identified by an expert. The clicks detected give valuable indication of the presence/absence of cetacean around the longline, the level of click detection allows us to dissociate the different acoustic behaviours leading to the detection of the depredation event.
Design of capacitive acoustic sensors using highly compliant microbeam arrays
Authors: Farahikia Mahdi , Miles Ronald
Published: December 2020

We have previously shown that the viscous forces acting on a periodic array of infinitesimally thin micro-beams due to air-borne sound are frequency-independent and directional [Mahdi Farahikia and Ronald Miles, “Viscous flow sensing using micro-beam arrays,” J. Acoust. Soc. Am. 146(4), 2837–2837 (2019)]. Utilizing this phenomenon in the design of acoustic sensors requires a means of converting their structural motion into electronic signals. Capacitive sensing, as a method for this purpose, requires the combination of both fixed and moving electrodes while eliminating the instability associated with high bias voltages [Ronald N. Miles, “A compliant capacitive sensor for acoustics: Avoiding electrostatic forces at high bias voltages,” IEEE Sens. J. 18(14), 5691–5698 (2018)]. In this study, the motion of moving micro-beams adjacent to fixed micro-breams in periodic arrays due to air-borne sound is examined through the finite element method. It is concluded that thinner, narrower micro-beams lead to a desired flat frequency response. The optimum gap between the micro-beams is found to be between 0.5 and 1 times the micro-beam width. The results from this study are fundamental in implementing a capacitive sensing mechanism to fabricate miniature acoustic sensors using micro-beam arrays.
Source level measurements of killer whale (Orcinus orca) echolocation clicks
Authors: Wladichuk Jennifer , Dosso Stan , Koblitz Jens , Lawson Jack
Published: December 2020

Biosonar is vital to odontocetes (toothed whales, dolphins, and porpoises) for navigation and finding food. Consequently, numerous details of their echolocation click parameters, such as source level and beam width, are known for many species; however, there is a data gap for killer whales (Orcinus orca). This information is essential for examining masking potential which could have an impact on their foraging abilities. The Southern Resident killer whales are an endangered population of orcas living along the Pacific coast of North America and underwater noise has been identified as a major threat towards their survival. This study used a 3D 24-element hydrophone array deployed in close proximity to wild killer whales to estimate source levels (SLs) and spectra of echolocation clicks. Future work will use these SLs to investigate masking potential from current and other noise scenarios.
Segmentation of induced substantia nigra from transcranial ultrasound images using deep convolutional neural network
Authors: Thirusangu Niranjan , Subramanian Thyagarajan , Almekkawy Mohamed
Published: December 2020

Parkinson's disease (PD) is an age-related neurodegenerative disorder, whose early diagnosis is challenging. PD neuropathology is characterized by a selective loss of dopaminergic neurons in the substantia nigra (SN). The echogenicity of SN is considered as an important biomarker for diagnosing PD. Since Ultrasound is well suited for measuring echogenicity, transcranial ultrasound images (TCUI) are used to diagnose PD and have become an industrial standard. But, ultrasound images usually have low resolution and are noisy compared to other medical imaging modalities. Thus, this whole method relies on the experience of the clinician to identify SN from the TCUI. To automate the process, we propose a deep convolutional neural network based on the U-Net architecture with a weighted binary cross-entropy (WBCE) loss function to do semantic segmentation of SN from the TCUI obtained. To alleviate the negative effects caused by noisy images, third-order Volterra filter is used for pre-processing. Furthermore, we compare the convergence rate of WBCE with standard BCE and other standard loss metrics, where WBCE outperforms others. We then, compare the results of the proposed U-Net architecture with a DenseNet based architecture and a U-Net and DenseNet based hybrid architecture, where we obtain better accuracy with the proposed architecture.
Ultrasonic anemometry on Mars
Authors: White Robert D. , Schmid Edward S. , Neeson Ian , Merrison Jonathan P. , Iversen Jens J. , Banfield Don
Published: December 2020

On Mars, we have yet to fully quantify and understand atmospheric turbulent transport (Banfield, JASA, 2016). The key required instrument is a wind sensor that can resolve horizontal and vertical winds, as well as the perturbations associated with turbulent eddies. On the surface, 10–20 Hz sampling and a sensitivity of 5 cm/s is required (McBean, 1972). Viking, Pathfinder, Curiosity, and Insight all used hot film or hot wire anemometers that can be confused by radiative heating and all have a response time of approximately 1 Hz. Sonic anemometry is an alternative high speed, high accuracy approach which uses differences in the acoustic phase delay to determine flow speed. Operation on Mars is challenging due to the low acoustic source strength and high attenuation in the thin (6–11 mbar) CO2 atmosphere, as well as large temperature variations (-100 °C to 20 °C). In this paper, we describe a three axis continuous wave piezoelectric anemometer with a high resolution and high precision analog phase detection circuit. Testing was in dry carbon dioxide between 2 and 20 mbar near 20 °C. At 6 mbar, we demonstrate resolution better than 10 cm/s, and accuracy of 3% at flow speeds up to 12 m/s. Low temperature testing is ongoing.
Weird science microphones are coming
Authors: Klasco Mike , Shaw Neil A.
Published: December 2020

Electret condenser microphone elements ruled for decades, are being displaced, at first in the late 1990s, and more rapidly in the last decade, by capacitive MEMs. Breaking the signal to noise ceiling at 70 dB in small consumer electronics microphone formats has been a tenacious barrier for far field voice control and sound pickup. Some existing conventional solutions and those just below the radar are more than promising. The advances in materials science in the last few years have been remarkable. Product demand in all categories, especially mobile electronics and voice command, are driving this rapid advancement. Some of these developments in materials and their application to existing microphones and for the next generation microphone products will be revealed. “Weird microphone science projects” that are jelling toward commercial productization, such as graphene electrostatic and ribbon mics, optical microphones, piezo MEMs, insect eye mics, and more will be explored.
Cryogenic testing of MEMS microphones towards their utilization as a quench detection method in superconducting magnets
Authors: White Robert D. , Zhao Zijia , Owen Casey , Anilus Mischael , Chau Steve , Desai Amish , Emerling Michael , Chiesa Luisa , Takayasu Makoto
Published: December 2020

High Temperature Superconducting (HTS) tapes such as Rare Earth Barium Copper Oxide (REBCO) are an attractive option for high field magnets operated in cryogenic fluids. However, quench events can occur in which the conductor locally loses its superconducting properties. It is critical to rapidly detect and respond to such an event. Conventional quench detection methods using voltage taps are difficult in HTS devices, since the normal zone propagation velocities are 2–3 orders of magnitude lower in HTS compared to low temperature superconductors (Iwasa, Cryogenics, 2003). We propose an alternative in which a linear array of MEMS microphones is distributed down the central cooling channel of a cable in-conduit conductor. The array can detect the acoustic signature caused by a quench event which propagates in the cooling fluid. The proposed method differs from Acoustic Emission (AE) detection, which uses sensors mounted on the magnet surface to detect structural vibration (Tsukamoto, Appl. Phys. Lett., 1981). In order to implement the system, MEMS microphones and preamplifiers must operate in cryogenic fluids. We report on characterization of commercial MEMS microphones in cryogenic gaseous helium between 0.5 and 1.5 bar down to 20 K, and in liquid nitrogen at 1 bar and 77 K.
Analytical and computational solutions for the acoustic damping of perforated microstructures
Authors: Naderyan Vahid , Raspet Richard , Hickey Craig J.
Published: December 2020

Efficient models for the viscothermal acoustic damping of perforated micro-electro-mechanical systems (MEMS) are essential in the designs of MEMS devices. In this work, the low reduced-frequency (LRF) method for viscothermal acoustic propagation is utilized to develop an analytical model for perforated MEMS. Also, a 3D finite element method (FEM) model including viscous and thermal effects is developed for the numerical computation of the problem. The results of the proposed analytical solution are in good agreement with the FEM. The applications of the model to predict and also to optimize the performance of the MEMS microphones will be discussed.
Quantitative analysis of the kowangan resonator in the bundengan musical instrument
Authors: Parikesit Gea O. , Kusumaningtyas Indraswari
Published: December 2020

This paper presents a quantitative analysis of the kowangan, a shield-shaped resonator used in the bundengan, a bamboo-based musical instrument from Indonesia. The kowangan resonator is made from a woven lattice of bamboo splits, covered with layers of bamboo sheaths, and then secured with palm sugar fibers. To gain insight into how this resonator works, it is required to first determine the shape of the resonator. Previously, we have developed a computational model of the resonator shape, where the distribution of curvatures in the resonator surface is driven by the minimization of potential bending energy in the woven lattice of bamboo splits. In the present study, we report the latest development in this work, where we have designed and built an optical imaging setup to measure the actual shape of a real kowangan resonator. Our measurement data allows for further improvements on our computational model, and consequently a deeper insight into the physics of the kowangan. The ultimate aim of this study is to build a full virtual prototype, not only of the kowangan resonator, but also of the whole bundengan instrument, which will be useful for the conservation and documentation of this endangered cultural heritage.
String instrument acoustic transfer processing
Authors: Rau Mark , Abel Jonathan S. , Smith Julius O. , James Doug L.
Published: December 2020

A real-time method of string instrument acoustic transfer which includes damping is proposed. Acoustic transfer of string instruments is relevant when trying to make a non-resonant instrument, such as an electric guitar, sound more similar to an acoustic guitar. Unlike previous acoustic transfer methods which only perform equalization, this method includes damping changes by using a time-varying filter which adds frequency-dependent exponential damping. Efficient digital filters are fit to bridge admittance measurements of an acoustic guitar and used to create equalization filters as well as damping correction filters. The damping correction filters work in real-time as they are triggered by onset and pitch detection of the signal measured through an under saddle pickup to determine the intensity of the damping.
An investigation of automatic flagging methods for aspiration noise in automobiles
Authors: Carr Daniel
Published: December 2020

If there are small gaps in the seal between a closed automobile door or window and the rest of the car, annoying noises may arise due to airflow through the gaps, or aspiration. While some aspiration noises contain clearly identifiable tones or narrowband components, many aspiration noises do not. As a result, it is often difficult to identify aspiration noise, whether by listening to the recorded sound, or by examining the measured spectrum. Aspiration noise is classified as an error-state, which manufacturers want to remedy before selling the car, so an automatic tool for flagging sounds containing aspiration noise would be helpful. A method for simulating aspiration noise was developed, in which stationary and intermittent components are added to a “base sound” having a spectrum representative of a certain automobile. These simulated sounds were analyzed using trends of single-value metrics and statistics such as Sharpness and estimated kurtosis, and spectral measures such as the power spectral density of time-varying Loudness. The trends observed in these quantities, and their effectiveness as robust aspiration-noise flags, are reported. Future work may include developing a holistic flagging tool for all wind noise error-states, including whistles, cavity noise, and separated flow turbulence noise.
Ultrasonic properties of Inconel 718 fabricated via laser-directed energy deposition
Authors: Huanes-Alvan Guillermo E. , Aydogan Beytullah , Sahasrabudhe Himanshu , Chakrapani Sunil Kishore
Published: December 2020

Laser-directed Energy Deposition (laser-DED) is an additive manufacturing process where a 3D structure is fabricated layer-by-layer with powder that is directed and melted using a high power laser. The processing parameters of laser-DED have a strong influence on the microstructure of the samples that are fabricated. Due to a very high cooling rate, laser-DED produces some unique microstructures like columnar, dendritic grains, and macro-micro grains. The objective of this study is to understand how these microstructures will influence the ultrasonic properties of Inconel 718 (IN718). This work focuses on frequency-dependent parameters such as ultrasonic phase velocity, attenuation coefficient, backscatter and absorption, since they can be related to microstructural features spread over multiple wavelengths: grain size, grain orientation, phases, etc.
Experimental determination of the elasticity of porous ceramics under the gas saturation and temperature treatment
Authors: Karunarathne Ashoka , Gladden Joseph
Published: December 2020

After the formulation of the theory of poroelasticity, which describes the elasticity of fluid saturated porous media, many experimental studies have been reported on the determination of the elasticity of porous materials under the various physical and structural conditions. However, there are limited studies on how the elasticity behave under the variation of the physical conditions of the saturated fluid. This study presents an attempt to characterize the influence of the pore-saturated gas media and their physical properties on the elasticity of porous ceramic materials. Resonant ultrasound spectroscopic measurements were performed on test specimens of alumina with ∼40% porosity, zirconia with ∼48% porosity, and sintered fully dense zirconia to determine the hydrostatic pressure-dependent macroscopic elasticity. Here, we report the variation of elasticity of porous and full dense samples over approximately five orders of magnitude (800–0.02 psi) in absolute pressure. A material softening with increased pressure was observed from the porous specimens and the rate of softening is quantified with different gas saturation by helium, nitrogen and argon. The time evolution of mechanical equilibrium of the porous materials at low pressure (0.02 psi) and moderately high-temperature (150 °C) conditions will also be discussed.
The role of lateralization in release from informational masking
Authors: Freyman Richard , Denson Kaitlyn , Fields Amber , Buss Emily , Zurek Patrick
Published: December 2020

This study tested whether target and masker must create different spatial percepts, in this case intracranial percepts created under headphones, to achieve spatial release from informational masking. Signals were sequences of 40-ms broadband noise bursts with four target bursts interspersed within a longer train of masker bursts. From a baseline sequence in which target bursts were 400 ms apart, either the second or third burst was advanced by 80 ms to create two different temporal patterns that subjects discriminated. Target bursts were intermixed among masker bursts such that pattern identification was at chance when all bursts were diotic, but near perfect when target and masker bursts were delivered with moderate interaural differences of opposite sign. Performance in these unprocessed conditions was compared to that obtained when stimuli were processed by an algorithm that swapped interaural differences in alternating frequency bands [S. Sheffield et al., J. Acoust. Soc. Am. 145, 1129–1142 (2019)], thereby degrading lateralization but preserving the magnitudes of interaural differences. Early results show substantially reduced masking release in degraded lateralization conditions, despite their preservation of interaural differences, suggesting a prominent role for perceived target-masker separation in spatial release from informational masking. [Work supported by NIDCD R01 01625.]
The role of attention in listening-in-noise
Authors: Newman Rochelle S. , Chatterjee Monita , Mulak Karen , Frick Janet , Shroads Emily
Published: December 2020

Listeners of all ages are faced with having to understand speech in the presence of noise. One factor that might influence listeners' success at this task is their ability to attend selectively. We examine both adults' and toddlers' understanding of speech in the presence of nonlinguistic background noise – noise that is either easier or harder to attend to selectively. We also test the same individuals on a nonlinguistic selective attention task. Adult listeners easily take advantage of acoustic cues such as spatial location and frequency-range differences to help them attend selectively to, and comprehend, the target speech. Young toddlers (under 2 years of age) fail to use these cues. In addition, among adults, success at listening in noise is correlated with performance in a visual selective attention task, suggesting that domain-general attention skills are relevant for adults' listening in noise. This is less clearly the case for young children, however; indeed, children who were more easily distracted by extraneous sounds showed better speech understanding in noise. These findings suggest that the relationship between performance in challenging listening conditions and other cognitive skills undergoes critical changes across development.
Exploring the effects of phonetic overlap and background noise on incremental processing in children
Authors: Liu Y. Sophia , Simeon Katherine , Grieco-Calub Tina
Published: December 2020

In everyday conversation, individuals actively process speech in order to comprehend and respond in real-time. As a word unfolds, listeners activate possible lexical candidates and actively determine the target word as soon as possible. This process requires knowledge of one's native spoken language and the ability to recognize individual phonemes. Phonetic overlap between the target and candidate words can influence the speed of lexical access. For example, phonological onset (e.g., candy), but not rhyming words (e.g., sandal), can yield lexical competition with target words (e.g., candle). When the auditory input is spectrally degraded, however, the effect is different: rhyme words have greater lexical competition with target words. The purpose of the present study is to test the extent to which rhyme words compete with target words in the present of background noise. In a visual world paradigm, the present study examines the time course of spoken word recognition when target words (e.g., candle) are contrasted with full (e.g., sandal) and offset (e.g., poodle) rhymes in 5-to-7-year-olds. Target words are presented in both quiet and in steady-state speech-shaped noise at 0 dB SNR. Preliminary data suggest that rhyming overlap does not impact processing in quiet but may show differences in noise.
Rapid adaptation to non-native speech: Effects of aging, hearing loss, and stimulus variability
Authors: Bieber Rebecca E. , Gordon-Salant Sandra
Published: December 2020

When communicating in challenging situations, most younger listeners with normal hearing are able to quickly adapt to the speech signal, improving their recognition with exposure. One potentially challenging situation is communication with non-native speakers whose second-language production (i.e., accented speech) is altered by the spectral and temporal characteristics of the L1. Older listeners, particularly those with age-related hearing loss, report considerable difficulty in recognition of non-native speech. A growing body of literature suggests that older adults can also perform rapid adaptation to non-native speech, but the conditions that might hinder or facilitate adaptation for these listeners remain unclear. In the present study, rapid adaptation was evaluated for three groups of listeners (younger with normal hearing, older with normal hearing, and older with hearing impairment) in conditions with increasing levels of stimulus variability. Generalization to unfamiliar talkers with familiar and unfamiliar accents was also assessed. Preliminary results indicate differing patterns of adaptation and magnitude of adaptation across conditions and listener groups. Generalization to an unfamiliar talker with a familiar accent appears greater following exposure to multiple talkers than following exposure to a single talker. Generalization to an unfamiliar talker with an unfamiliar accent appears limited.
Effect of envelope signal-to-noise ratio on the intelligibility of speech in speech-spectrum shaped noise
Authors: Soleymanpour Rahim , J. Brammer Anthony , Kim Insoo
Published: December 2020

In attempts to improve speech intelligibility, the envelope of speech in noise is commonly processed in the time domain and used to amplitude modulate the corrupted speech. In this study the envelope was constructed from the noisy speech, but separately and independently of the SNR of the noisy speech. Envelopes corresponding to 0, −3, −6, and −9 dB SNR were applied to the noisy speech when the latter had an SNR of either −9, −6, −3, or 0 dB, to evaluate the benefit to intelligibility of improving the SNR in the modulation domain. Signals from 200 Hz to 6 kHz were processed by MATLAB into sixteen contiguous subbands with bandwidth approximately 1.5×ERB of an auditory filter. The subband envelopes were formed from the absolute value of the signals and low-pass filtered. Eleven subjects aged 29 ± 8 years (mean and range) with normal hearing underwent the Modified Rhyme Test to assess speech intelligibility. The stimuli were presented diotically over earphones with the subject seated in an audiometric room. Statistically significant increases in mean word score of up to 35% could be obtained by improving the envelope SNR, suggesting this processing may benefit speech intelligibility. [Work supported by NIOSH.]
Intelligibility of dysphonic speech in auralized classrooms
Authors: Murgia Silvia , Puglisi Giuseppina Emma , Sierra Tomas E. , Astolfi Arianna , Ishikawa Keiko , Bottalico Pasquale
Published: December 2020

Voice disorders reduces speech intelligibility. This study evaluated the effect of noise, voice disorders and room acoustics on vowel intelligibility. Twenty-nine college students listened to 11 vowels in /h/-V-/d/ format. The speech was recorded by three adult females with dysphonia and three adult females with normal voice quality. The recordings were convolved with two oral-binaural impulse responses with 0.4 s and 3.1 s of reverberation time. The intelligibility and the listening easiness were significantly higher in quiet condition, when the speakers had normal voice quality and in low reverberated environments, while the response time of the listener was longer in noise condition.
Insights into rapid adaptation to Spanish-accented English words in younger and older adults
Authors: Bieber Rebecca E. , Tinnemore Anna R. , Gordon-Salant Sandra
Published: December 2020

Older adults often report difficulty understanding speech produced by non-native talkers. Although numerous studies have described auditory training protocols to improve speech recognition in noise, there are comparatively few studies evaluating auditory training for improving recognition of non-native speech. However, there is evidence that older adults can achieve short-term, rapid adaptation to non-native speech. In this study, a word-level training paradigm was employed, targeting improved recognition of Spanish-accented English. Younger and older adults with normal hearing or hearing impairment were trained on Spanish-accented monosyllabic word pairs containing four phonemic contrasts (initial s/z, initial v/f, final b/p, final d/t) produced in English by multiple male native Spanish speakers. Listeners completed pre-testing, training, and post-testing, over two sessions. While the training protocol failed to elicit any long-term learning for Spanish-accented speech, detailed examination of listeners' performance during the pre-testing revealed patterns of rapid adaptation that appear to vary by phonemic contrast and that may be dependent on the acoustic features of the stimulus. Statistical methods such as growth curve modeling and generalized additive mixed models are employed to describe the patterns of rapid adaptation, and how they vary between listener groups and different stimulus types.
Articulation and identification of voiced stop consonants produced by acoustically driven vocal tract modulations
Authors: Story Brad H.
Published: December 2020

A recently developed model of speech production [Story & Bunton, JASA, 146(4), 2522–2528] was used to generate VCVs that were examined with regard to both articulation and identification of the consonant. In this model, an utterance is generated by specifying relative acoustic events along a time axis. These events consist of directional changes of the vocal tract resonance frequencies called resonance deflection patterns (RDPs) that, when associated with a temporal event function, are transformed via acoustic sensitivity functions, into time-varying modulations of the vocal tract shape. RDPs specifying /b/, /d/, and /g/ would typically be coded as [−1 −1 −1], [−1 1 1], and [−1 1 −1], respectively, indicating, from left to right, the targeted directional shift of the first, second, and third resonances of the vocal tract. In this study, two types of V1CV2 continua were constructed in three vowel contexts (/i, a, u/) by incrementing in small steps (1) the second resonance deflection from −1 to 1, and (2) the third resonance deflection from 1 to −1. The resulting time-varying vocal tract shapes emulate expected articulation patterns for the stop consonants, and a perceptual experiment indicated that listeners identify the consonants based on the polarity of RDP values.
Effects of velopharyngeal size, airflow rate, and microphone placement on nasalance score
Authors: Rollins Michael , Oren Liran
Published: December 2020

Nasometers are designed to measure the nasalance score, which is the ratio of nasal acoustic energy to total (nasal plus oral) acoustic energy during production of sonorant phonemes. However, nasometer microphones can detect hydrodynamic pressure changes in addition to acoustic pressure changes. This can occur when a talker with incomplete velopharyngeal closure leaks airflow through the nasal cavity; these nasal emissions lead to increased aerodynamic flow impinging on the nasal microphone, which may significantly increase the nasalance score. In order to quantify the influence of nasal emissions on the nasalance score, airflow with no voiced component was passed through an [s]-postured airway model based on a subject-specific geometry. Nasometer microphones measured pressure fluctuations exterior to the nose and mouth, from which the nasalance score was calculated. Flow rate, size of the velopharyngeal opening, and microphone position (medial or lateral) were varied in a factorial experiment. It was found that in the presence of nasal emissions, placing the nasometer microphones laterally decreases the nasalance score. Furthermore, the nasalance score generally increases with increased velopharyngeal opening size. These results indicate that hydrodynamic pressure from nasal emissions can increase the nasalance score and that this influence could be mitigated via microphone placement.
The relation between category compactness and L2 VOT learning
Authors: Huffman Marie K. , Schuhmann Katharina S.
Published: December 2020

L1 and L2 category compactness have been reported to correlate with L2 vowel pronunciation accuracy in advanced intermediate learners (Kartushina and Frauenfelder, 2014). However, it is not clear whether category compactness is an effect of L2 learning, or whether it is an individual characteristic that might predict aspects of L2 learning. Holliday (2015) suggests that more variable VOT categories early in L2 learning may facilitate acquisition of new L2 VOT patterns. We tested relationships between L1 and L2 category compactness and L2 pronunciation progress for voiceless stops, in ten L1 English-L2 Spanish learners over the course of one semester of early Spanish courses. We found that lower L2 Spanish VOT correlated with higher voiceless VOT standard deviation at the end of the semester for all but the absolute beginners (R2 = 0.6256, F(1,5) = 37.75, p = 0.004). Thus, for early learners, as production improves, L2 categories may expand. In addition, L1 English voiceless stop VOT category compactness at beginning of term correlated with L2 Spanish VOT accuracy at end of term for all learners (R2 = 0.6798, F(1,9) = 17.0, p = 0.003), suggesting that L1 category compactness may reflect individual properties that influence progress in L2 learning.
The role of passage length on acoustic voice variability in bilingual speech
Authors: Johnson Khia A. , Babel Molly
Published: December 2020

An individual's voice is determined in part by the limitations of their anatomy and physiology, in addition to language-specific phonological and phonetic structure. When a bilingual switches between languages, how much do they change their voice? Previous work using a corpus of spontaneous speech from early Cantonese-English bilinguals found surprisingly little variability across individuals' languages [Johnson et al., Proc. of Interspeech (2020)] compared to earlier research on across-talker acoustic voice variability [Lee et al., JASA (2019)]. A crucial difference between these two studies, however, is passage length. A longer passage (e.g., 30 min) potentially allows for a more stable structure to emerge in a principal components analysis, while a shorter sample (e.g., 2 min or less) may instead be subject to ephemeral variation, and potentially misrepresent the overall variability of a voice. Building on Johnson et al. (2020), the present study asks: to what extent does passage length impact the results of principal components and canonical redundancy analyses designed to elucidate within-talker (across languages) and across-talker (within language) idiosyncratic variation? These results are important for theories of talker recognition, identification, and discrimination, in addition to improving understanding of talker-specific acoustic-phonetic variation.
Automated matching of measured long-range acoustic arrivals from autonomous gliders with acoustic predictions
Authors: Graupe Cristian E. , Van Uffelen Lora , Dzieciuch Matthew A. , Howe Bruce M. , Worcester Peter F.
Published: December 2020

The acoustic arrival matching localization method estimates the range of a mobile receiver from a fixed broadband acoustic source by matching the arrival with an acoustic prediction of the received arrival at a known range, calculating an offset from the known range, and combining the estimates of range from multiple sources using least-squares to estimate subsurface position. This is a labor-intensive task performed in post-processing, after recovery of the mobile platform. Automation of this matching is not straightforward due to the presence of spurious arrivals and other variations in the measured arrivals compared with predictions. Automated methods for estimating the range errors and performing ray identification for specific peak arrivals were developed using both programmatic and machine learning approaches. These methods take advantage of the temporal structure of the measured arrivals and simultaneously estimate range error and resolve measured peaks by comparing against a reference acoustic propagation model that describes the progression of the acoustic arrival structure in depth, range, and reduced travel time. The programmatic and machine learning approaches will be tested on range dependent ray simulations and evaluated in the context of a dataset collected using Seagliders during the North Pacific Acoustic Laboratory (NPAL) Philippine Sea Experiment.
A quantitative soundscape analysis of the Canadian Arctic, 2014–2019
Authors: Halliday William D. , Barclay David R. , Cook Emmanuelle , Dawson Jackie , Hildebrand John , Hilliard Casey , Hussey Nigel , Jones Joshua , Juanes Francis , Marcoux Marianne , Niemi Andrea , Nudds Shannon , Pine Matthew , Richards Clark , Scharffenberg Kevin , Westdal Kristin , Insley Stephen
Published: December 2020

In the Arctic, sound levels have historically been strongly tied to sea ice and wind speed, with very little impact of anthropogenic noise. However, climate change is causing a loss of sea ice, and consequently increased ship traffic and anthropogenic underwater noise. Here, we present the first quantitative, comparative analysis of underwater sound levels across the Canadian Arctic. We analyzed 39 passive acoustic datasets collected throughout the Canadian Arctic from 2014 to 2019 to examine spatial and temporal trends in sound pressure levels (SPL), quantify environment drivers of SPL, and estimate the influence of ship traffic on SPL. Daily mean SPL in the 50–1000 Hz bandwidth ranged from 70 to 127 dB re 1 μPa (median = 91 dB). SPL increased as wind speed increased, but decreased as both ice concentration and air temperature increased. The highest SPLs were in August-October, and the lowest in March–April. SPL increased as the number of ships increased. The highest mean SPLs were recorded near southeast Baffin Island, but the most ship noise was recorded near Pond Inlet (>1 ship/day in summer). This study provides an important baseline for underwater sound levels in the Canadian Arctic, and fills many geographic gaps on published underwater sound levels.
Articulatory activity of the tongue, jaw, and lips during the second passaggio acoustic transition of female singers
Authors: Lissemore Richard C. , Shadle Christine H. , Roon Kevin D. , Whalen D. H.
Published: December 2020

Sopranos typically exhibit an acoustic modification between 600 and 700 Hz (on /a/) during which second resonance (R2) tracking of the second harmonic (2fo) changes to first resonance (R1) tracking of the fundamental (fo). To quantify the alteration, the sound pressure level difference between the first two harmonics (L1-L2) was measured for chromatic scales sung between C5◻ and G5◻ (523 to 784 Hz) by 17 sopranos (9 judged by the first author as “techniqued” and 8 as “un-techniqued” and confirmed by perceptual experiment). Techniqued sopranos shifted from negative to positive values of L1-L2 as early as D5◻ (587 Hz), while the least techniqued singers did not make the change at all. Articulatory correlates were measured using ultrasound of the tongue and optical tracking. Head-corrected tongue contours showed the most critical articulatory factor to be the size of a triangular area between two points on the hard palate and the most anterior tongue point. Sopranos who made the change earliest exhibited the largest anterior oral cavities whereas sopranos who never made the acoustic change had significantly smaller anterior cavities. Larger anterior oral cavities appear to accommodate lower frequencies of R2, presumably lowering L2 and increasing L1-L2. [Work supported by NIH grant DC-002717.]
Using cluster analysis and hearing histories to predict performance outcomes among bilateral cochlear-implant users
Authors: Jaekel Brittany N. , Goupell Matthew J.
Published: December 2020

Cochlear-implant researchers are often interested in how participants' hearing histories impact performance. For example, it is common to include duration of deafness, age at onset of deafness, and age at implantation as covariates in statistical analyses. Unfortunately, multi-collinearity often exists among hearing history variables, which can affect the convergence of statistical models. This problem could be alleviated by using cluster analysis, a statistical method that can sort participants into groups based on their similarity on a set of variables. Cluster membership, rather than collinear hearing history variables, can then be entered into statistical models. To measure the efficacy of this method in cochlear-implant research, we performed a cluster analysis on the bilateral cochlear-implant users in our lab's database with complete hearing history information (n = 53). Bilateral cochlear-implant users were chosen for this initial analysis to measure whether across-ear differences affect outcomes. Four clusters emerged based on demographic and hearing history variables. Preliminary analyses showed that cluster membership could serve as a useful predictor for performance outcomes in bilateral cochlear-implant users. Validating clusters in the greater cochlear-implant user population could result in useful information for audiologists counseling potential implant candidates about expected outcomes.