bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrasound propagation in bone
Authors: Wear Keith A.
Published: November 2017

Bone sonometry is a rapidly evolving diagnostic technology for managing osteoporosis. Bone sonometers that measure ultrasound propagation through calcaneus or along long bones (parallel to the long axis) have been used for many years. However, the Food and Drug Administration recently cleared two new, innovative designs that measure ultrasound propagation perpendicular to long axes of tibia (2016) and radius (2017). A basic understanding of wave propagation in bone is required in order to compare devices based on different physical principles and skeletal sites. Phantom studies elucidate the relative importance of components of signal loss during propagation through bone: absorption, longitudinal-to-shear scattering, and longitudinal-to-longitudinal scattering (Wear, IEEE Trans. UFFC, 55, 2418–2425, 2008). Comparison of experimentally-measured ultrasound properties (attenuation, sound speed, and backscatter coefficient) and finite-element-analysis-derived mechanical properties in vitro (n = 25) indicate that ultrasound measurements provide additional information regarding fracture risk beyond that provided by bone quantity alone (Wear et al., Bone, 103, 93–101, 2017). Bone can support two longitudinal waves, which often overlap in time and frequency domains but can be separated using Bayesian probability theory or the modified least-squares Prony’s (MLSP) method (Wear et al., J. Acoust. Soc. Am., 136, 2015–2024, 2014).
A new dual-mode ultrasonic technique for assessing cortical bone
Authors: Kaufman Jonathan J. , Luo Gangming
Published: November 2017

Osteoporotic fractures are a major public health problem; diagnosis is based on x-ray densitometry (DXA); however, DXA is not able to accurately predict who will and will not suffer a fracture. An alternative to DXA is ultrasound, which is viewed as having the potential to better characterize fracture risk. Our approach is based on “dual-mode“ ultrasound in which 2 distinct modes are used together to assess cortical bone. In particular, measurements are made at the mid-shaft tibia in both axial-transmission and pulse-echo modes. Axial transit time (τA) and pulse-echo transit time (τP/E) are obtained at the same tibial cortical site. These 2 transit times can be used in a classification scheme to identify individuals at greatest risk of fragility fracture. A pilot set of measurements on 5 individuals has been carried out to demonstrate the basic feasibility of the proposed technology. For the 5 subjects, each subject data point was found to be located in a distinct region (i.e., a hypothesized distinct bone quality state) of the quadrant associated with the 2 transit times. Because the 2 transit times are each affected in distinct fashions by a variety of bone quality factors (such as degree of mineralization, porosity, cortical thickness, and biomechanical stiffness), the bivariate feature has the potential to accurately identify those individuals at increased risk of fracture. Future studies on individuals with and without fragility fractures will elucidate the capabilities and potential of the dual-mode ultrasound technology.
Diffusion constant and frequency dependent attenuation for the assessment of cortical bone porosity
Authors: Yousefian Omid , Karbalaeisadegh Yasamin , Muller Marie M. , Iori Gianluca , Raum Kay
Published: November 2017

The objective of this study is to assess cortical bone porosity through measurements of the diffusion constant and attenuation as a function of frequency. Using FDTD simulations, the diffusion constant was calculated for 45 modified human femur shaft bone geometries obtained from a reference binarized 100-MHz Scanning Acoustic Microscopy image. The diffusion constant was sensitive to cortical porosity and demonstrated around 85% decrease for 10% increase in porosity. This suggests that lower diffusion constant values could be associated with more severe cases of osteoporosis. Using a spectroscopy approach in the 1–8 MHz range, we demonstrate that the attenuation coefficient as a function of frequency can be approximated as:α(f) = AfB + C, where “A”, “B” and “C” are related to pore diameter and pore concentration. For a constant pore density (10 mm2), “A” increased from 0.03 to 19.79 when pore diameter increased (Po.Dm ∈40–130μm), while “B” and “C” were found to decrease from 2.654 to 0.5741 and from −0.061 to −21.43, respectively. A similar trend was observed when pore diameter was kept constant. A model was derived to quantify pore size and concentration through constrained nonlinear optimization method. This parametric model combined with estimation of the diffusion constant has the potential to enable the quantification of pore size and concentration.
Associations between ultrasonic backscatter, bone density, and microstructure in cancellous bone characterization
Authors: Ta Dean , Liu Chengcheng
Published: November 2017

Ultrasonic backscatter is related to the microstructure of cancellous bone. However, whether backscatter measurement can provide additional information independently of BMD remains speculative. In this study, we analyzed the independent contribution of cancellous bone densities and microstructure to apparent backscatter signals in vitro. The results showed that ultrasonic backscatter and the statistics of backscatter envelope were significantly correlated with bone densities and microstructure. After adjustment for BMD, some trabecular structures still contributed significantly to the adjusted correlations, with moderate additional variance explained. Multiple linear regressions revealed that both bone density and structure contributed significantly to the prediction of ultrasonic backscatter (adjusted R2 = 0.75–0.93, p<0.05), explaining an additional 14.0% of the variance at most, compared with that of BMD measurements alone. We also demonstrated that the Nakagami model had great potential in trabecular microstructure characterization. The results proved that ultrasonic backscatter was primarily determined by bone apparent density, but bone densities plus microstructure structure could achieve encouragingly better predictive performance than BMD alone. This study implied that ultrasonic apparent backscatter might provide additional density and structural features unrelated to current BMD measurement. Thus, we suggest that ultrasonic backscatter measurement could play a more important role in cancellous bone evaluation.
Timbre analysis from monotone rearranging of the acoustic signal: Application to fountains
Authors: Velardi Laura , Hermand Jean-Pierre , Roberto D'Autilia
Published: November 2017

Public fountains are an example of a soundmark that is both non musical and pleasing to the ear due to their specific timbre. Standard audio descriptors designed for musical sounds are limited in describing such sounds. A new method is proposed for identifying and classifying fountains sounds as well as surrounding urban noises. The method consists in sorting discrete-time signal samples in a monotonically descending order. Features of the resulting curve are extracted in an attempt to define a timbral evaluation metric. Reference signals including natural water sounds and synthesized pink noise are also analyzed and the results are compared to those of fountain sounds. Outcomes are discussed in the framework of urban soundscape studies, in order to improve acoustical urban planning.
A micromachined microphone based on the electret membrane and field-effect-transistor mechano-electrical transduction
Authors: Kim Junsoo , Lee Hoontaek , Seo Donghwan , Jin Jaehyeok , Shin Kumjae , Moon Wonkyu
Published: November 2017

Most commercially available MEMS (Micro-Electro-Mechanical-System) microphones use a capacitive method, and their structure and performance are saturated to some extent. However, due to the limitation of the capacitive transduction method, the roll-off at the low frequency is inevitable, and there is a limit in reducing the mechanical thermal noise caused by the squeeze film damping that occurs between membrane and backplate structure. Proposed electret membrane and FET (Field Effect Transistor) based MEMS microphone detects a change in the source-drain current according to the gate voltage change of the FET induced by vibrating the membrane with the fixed charges. In the case of a MEMS microphone using the proposed FET, low frequency roll-off according to the energy conversion does not occur, and the size of the backplate can be drastically reduced as compared with the conventional MEMS microphone, thereby further reducing the mechanical thermal noise, leading to the possibility of achieving the higher SNR (Signal to Noise Ratio) than 65 dBA. Conventional metal-oxide-semiconductor fabrication process and micromachining process were used. In this study, design, fabrication and performance test of the proposed FET based MEMS microphone are conducted. [Work supported by CMTC, UM15304RD3.]
Fluid dynamics approach to free reed physics
Authors: Tonon Thomas
Published: November 2017

The periodic vibration of a free reed subject to a steady pressure gradient (bellows pressure) is examined from a fluid dynamics approach. In this analytic study, the self-excited forcing function is modeled from the static and dynamic pressures acting on the vibrating tongue surface. A first formulation includes standard mounting of the reed over a cavity, with a hole that accommodates a mean air flow to the outside. A second formulation includes in addition a resonant air geometry that could include non-standard operation, such as pitch bending.
Cultural significance of the diatonic single-row button accordion in South Louisiana
Authors: DeWitt Mark F.
Published: November 2017

Musical acoustics are intimately bound up in culture. Musical instruments are vehicles for artistic expression in terms of visual design, timbre, and musical style for musicians who play them and sometimes for the artisans who make them. In complex multicultural societies, certain instruments can also become icons for group identity, similarly marked in visual, timbral, and musical terms. The case of the melodeon, known in Louisiana as the single-row button accordion or the Cajun accordion, richly exemplifies these possibilities. The instrument arrived in Louisiana in the mid-to-late 1800s and became the instrument of choice to play at house dances and dance halls by the 1920s, adopted by two neighboring ethnic groups, French-speaking Creoles of color and Cajuns. Local artisans began making single-row accordions when the supply from Germany ceased during World War II, creating a new, higher-quality version of the instrument with a distinctive appearance that continues to be the instrument of choice for Cajun accordionists and some zydeco players. This paper will elaborate on the history of the melodeon in Louisiana, the musical styles that use it, and its status as a regional and ethnic identity symbol.
Focal zone characteristics of stepped Fresnel and axicon acoustic lenses
Authors: Lirette Robert L. , Mobley Joel
Published: November 2017

Flat Fresnel and axicon acoustic lenses were developed and characterized both numerically and experimentally. Flat lenses have a compact profile leading to less attenuation and phase distortion in the bulk lens material. Fresnel lenses approximate spherical focusing to a fixed point whereas the axicon focuses to a narrow focal line, producing a tighter lateral beam over a longer depth. Numerical models of the sound pressure field from both types of lenses were done using the angular spectrum method. The lenses were 3d printed with polylactic acid (PLA) and also lathe cut with transparent polystyrene. Pulse-echo measurements of the sound speed were done for both materials. Pressure field scans were conducted using a 1.2 MHz planar transducer in a hydrophone scanning tank. These scans demonstrate the focusing effect of both types of lenses and are in agreement with the numerical model.
Focus control in the radial direction using an ultrasound liquid crystal lens
Authors: Shimizu Yuki , Koyama Daisuke , Harada Yuki , Emoto Akira , Matsukawa Mami
Published: November 2017

Nematic liquid crystal is widely used in optical devices such as liquid crystal displays and controlled by electric fields through the liquid crystal layer. Our group has proposed a control technique of liquid crystal molecular orientation using ultrasound vibration without indium tin oxide electrodes [1]. In this study, using ultrasound and nematic liquid crystal, we realized a variable focus liquid crystal lens. The liquid crystal lens has no transparent electrodes and consists of a simple structure; a nematic liquid crystal layer with a thickness of 50 μm is formed between two circular grass plates. An annular PZT ultrasonic transducer was bonded on the glass plate. By exciting the transducer at the resonance frequencies (28 kHz), the flexural vibration modes were generated. The acoustic radiation force from the vibration changed the molecular orientation of the liquid crystals, which induced the distribution of the execution refractive indices. The liquid crystal layer then worked as a lens. The focal points could be controlled by the radiation force and moved in the radial direction. [1] S. Taniguchi, D. Koyama, Y. Shimizu, A. Emoto, K. Nakamura, and M. Matsukawa, Appl. Phys. Lett. 108(2016), 101103.
Enhancement of low-frequency sound emission by metamaterial enclosures
Authors: Zhang Likun , Zhao Jiajun , Wu Ying , Landi Maryam
Published: November 2017

Emission of low-frequency sound by a source is limited by the size of the source relative to sound wavelength. We propose to place the source in a subwavelength enclosure of anisotropic metamaterials which enhances the emission around Mie resonant frequencies of that enclosure [J. Zhao, L. Zhao, and Y. Wu, J. Acoust. Soc. Am. 142(1), EL24–29, July 2017]. The enclosure has a relatively small sound speed along the radiation direction, enabling the resonances to occur at low frequencies. Our numerical simulations provide evidence of the proposed low-frequency enhancement for both monopole and multipole sources. The common Mie resonant frequencies increase with the order of the multipoles. Here, we introduce an extreme anisotropy in the azimuth of the enclosure to degenerate the resonant frequencies of higher-order multipoles down to the same frequencies as the lower-order multipoles. The degeneracy associated with the anisotropy of the enclosure is theoretically analyzed. The results guide the experimental realization of the enclosure for low-frequency enhancement.
Experimental realization of enhancing low-frequency sound emission by metamaterial enclosure
Authors: Landi Maryam , Zhang Likun , Zhao Jiajun , Wu Ying
Published: November 2017

A solution to the low radiation rate of a sound source has been proposed by using metamaterial enclosures of degenerated Mie resonances [J. Zhao, L. Zhao, and Y. Wu, J. Acoust. Soc. Am. 142(1), EL24–29, July 2017]. This talk presents our experimental realization of this enhancement for a monopole source. The enclosure with a low sound speed is created by a coiling-space structure fabricated by 3D printing. A small balanced-armature speaker with a 1 mm speaker mouth is placed at the enclosure center to radiate impulsive sound signals. The diameter of the structure is only one seventh of the wavelength of the sound at the maximum enhancement, corresponding to the lowest resonance. The enhanced sound pressure is more than two orders of magnitude larger than the sound pressure without the enclosure. The measurements of sound pressure at different angles in the space show the omnidirectionality of the enhancement. This enhancement is demonstrated as a result of enhanced density of states, i.e., the increased number of modes per unit frequency range and per unit volume, which we relate to Fermi's Golden rule and Purcell effect in quantum systems and find the analog in acoustics.
Vowel-to-vowel coarticulation in Spanish non-words: Effects of stress and consonantal context
Authors: Conklin Jenna , Dmitrieva Olga
Published: November 2017

In spoken language, gestural overlap in speech production regularly leads to coarticulation between neighboring segments, resulting in assimilation measurable by changes in the acoustic parameters. Vowels in adjacent syllables can coarticulate in a phenomenon called vowel-to-vowel coarticulation, which is subject to variation based on environmental factors such as surrounding consonantal context and the placement of stress. This study investigates vowel-to-vowel coarticulation in Spanish in order to better understand the effect of stress and consonantal context on coarticulation. Formant analysis of vowels produced by 20 native speakers of Spanish was used to determine the presence and direction of coarticulation in trisyllabic nonce words with varying stress (/CVCVCV/ words, vowels /e, o/ as targets and /e, i, o, u/ as triggers, /k/ and /p/ contexts). Results showed that both anticipatory and carryover vowel-to-vowel coarticulation was present at vowel edges in all contexts, but only carryover coarticulation in backness extended to vowel midpoints. Stress placement mediated the coarticulatory effect with select target and trigger combinations in carryover coarticulation, while consonantal context played a greater role in anticipatory coarticulation. When stress played a role, unstressed target vowels were more susceptible to coarticulation, while stressed targets resisted coarticulatory effects.
The phonetic effects of onset complexity on the English syllable
Authors: Mai Anna
Published: November 2017

In English, onset segments of the syllable do not participate in the categorical criteria which determine phonological syllable weight, yet they probabilistically impact stress assignment in novel words and influence the composition of weight-based metric verse (Kelly 2004, Ryan 2014). Together these observations suggest a phonetic motivation for the role that onsets play in English’s phonological syllable weight system, investigated here. Using 20 rhyming sets of single syllable words minimally differing in onset material (i.e., rap, trap, strap), this production study replicates results from the literature showing that the addition of segmental material to the onset accompanies a decrease in vowel duration (Gordon 2005, Ryan 2014). Furthermore, results show that the pitch and amplitude maxima of the syllable occur earlier within syllables containing more onset segments. Pitch and amplitude maxima have previously been implicated in perceptually based accounts of syllable weight (Goedemans 1998), and since stimuli were controlled for stress and categorical weight, these results suggest that the phonetic effects observed reflect general acoustic properties of onset complexity in the language. For these reasons, findings reported here suggest that perceptual acoustic effects intrinsic to onset complexity are exploited by the weight system of English despite exclusion from its categorical criteria.
An electromagnetic articulography study of stop-/s/ and /s/-stop clusters in Greek
Authors: Doli Evdoxia , Reidy Patrick , Katz William F.
Published: November 2017

Previous kinematic studies on consonant clusters suggest that many factors affect their articulatory timing, including speech rate, frequency of occurrence, and prosody. Other possible factors include the direction of articulatory movement (front-to-back, back-to-front), whether independent articulators (e.g., tongue and lips) or single articulators (e.g., tongue tip and tongue body) are involved, as well as the relative sonority of the consonantal segments. In this study, five talkers of Modern Greek produced the clusters /sp/, /ps/, /sk/, and /ks/ in the carrier phrase “Ipa_______pali” (I said________again). These clusters varied in articulatory direction, articulatory independence, and sonority patterns. We used four methods to determine the degree of articulatory overlap. Each method yielded durations (ms) between gestural landmarks, which were used to compute consonant overlap. The methods differed in the ways gestures were interpreted from the velocity signal (e.g., using extrema or 20% threshold) and how consonant overlap was computed. Preliminary results indicate that articulatory direction and relative sonority exerted the strongest effects on speakers’ productions, while articulator dependence/independence played no apparent role.
The distribution of the retroflex lateral allophone of the liquid phoneme in Korean
Authors: Rhee Nari
Published: November 2017

The liquid phoneme in Korean is known to have an optional retroflex allophone in syllable-final positions (Lee 1999). However, there lacks literature evaluating when and how this retroflex allophone is realized. To define the distribution of the retroflex allophone of the liquid phoneme in Korean, this study uses a read speech corpus of Seoul Korean to track the rhotacization of the liquid phoneme in coda positions. Rhotacization of the liquid is detected and measured by the lowering of the third formant. Preliminary results show that the liquid phoneme in coda position is realized as retroflex when preceded by a back vowel, and when followed by another liquid phoneme (gemination). The results suggest that the liquid phoneme is not simply optionally rhotacized in coda positions; instead, the retroflex allophone is realized in contexts defined by the preceding vowel and the following consonant. Future research remains to further examine the articulatory and perceptual aspects of the rhotacization.
A regression approach to vowel normalization for missing and unbalanced data
Authors: Barreda Santiago , Nearey Terrance M.
Published: November 2017

Researchers investigating the vocalic systems of languages or dialects frequently employ normalization methods to minimize between-speaker variability in formant patterns while largely preserving dialectal, between-phoneme variability. One popular method, log-mean normalization, relies on estimating the logarithm of the geometric mean formant-frequency (Gs) produced by a speaker across their vocalic inventory, and then expressing the formant patterns produced by a speaker as deviations from this mean. However, in the face of missing or unbalanced data, the traditional approach to calculating Gs for a speaker will usually lead to biased estimates, which will produce artificial asymmetries in the normalized vowel spaces of different speakers. An alternative method is proposed for the estimation of Gs based on a linear-regression framework, which avoids the biases associated with traditional estimation of Gs when data is unbalanced. The regression method to normalization is described, and simulations are carried out to compare the accuracy of Gs estimates via regression to other estimation methods. Results indicate that the proposed method is substantially more accurate than the traditional approach to estimating Gs in the face of missing or unbalanced data.
Variable vowel convergence in a novel cooperative task
Authors: Nycz Jennifer , Mooney Shannon
Published: November 2017

Phonetic convergence is partly automatic, yet mediated by linguistic and attitudinal factors; salient social identity can suppress convergence or lead to divergence (Babel 2010). We assessed convergence across vowels among 12 pairs of speakers using a novel task that minimizes the salience of identity. Each person separately read aloud a 45-item word list, once before the main task and again afterwards. Between readings, the pair played a version of the game Taboo, in which players take turns attempting to elicit specific words from their partner while avoiding forbidden words. Lobanov-normalized formant values were extracted from the word lists. A convergence measure was calculated for each word for each pair, by subtracting the Euclidean distance between the speakers’ vowels in that word in post-game lists from that of the pre-game lists. Mixed-effects models of convergence were fit, with random effects for word and pair and fixed effects for vowel and pre-game distance. Greater initial distance was associated with greater convergence. /i/ and /a/ converged most consistently, while diphthongs typically diverged. This suggests that listeners focus on point vowels to model an interlocutor’s vowel space, facilitating convergence in these vowels, and that even when identity is not salient, divergence may occur.
New platforms, technologies, and approaches for remote inference of physical and biological parameters using acoustic scattering techniques
Authors: Lavery Andone C.
Published: November 2017

Active narrowband acoustic scattering techniques have been used for decades to study the distribution of marine organisms, such as fish and zooplankton, and to image physical oceanographic processes, such as internal waves and microstructure. In the last decade or so, these techniques have been extended to the use broadband acoustic scattering techniques for more accurate inference of relevant biological and physical parameters, such as size or abundance of organisms or intensity of mixing. Rapid advances in instrumentation and deployment platforms have also enabled new insights to be gained. In this presentation, a brief overview of this research area is given. Then, results from a decade of work on the development and implementation of broadband scattering techniques for studying physical and biological processes over relevant spatial and temporal scales are presented. Finally, recent data from an estuarine plume, collected with a broadband sonar integrated onto a Remus-100 Autonomous Underwater Vehicle, are presented. Advances and limitations of new platforms and sensors to the future of acoustical oceanography are considered.
Balancing the detrimental effects of office noise annoyance and distraction on work performance
Authors: Lawless Martin S. , Vigeant Michelle C. , Dittberner Andrew
Published: November 2017

Broadband, steady-state background noise can improve open office conditions by facilitating speech privacy and reducing distraction caused by intermittent, occupancy-generated noise. The background noise is typically generated by HVAC systems, though can be added with loudspeakers to boost speech masking. However, too high background noise levels can cause annoyance, fatigue, and other noise-related symptoms. It is yet unclear whether noise annoyance or distraction impairs work performance more. This study investigated the trade-off between noise annoyance and distraction, as well as their effects on acoustic dissatisfaction and performance. Subjects performed cognitive tasks while exposed to simulated office acoustic environments reproduced using higher-order Ambisonics. At fixed time intervals, the subjects could change the acoustic environment by adjusting either the background or intermittent noise levels. Lowering background noise caused the intermittent noise to rise, and vice versa. By the end of testing, it was expected that each subject equalized their dissatisfactions of the two noise types. Annoyance and distraction were assessed with a survey at each time interval. Physiological measures, including heart rate variability and skin conductance, were collected to correlate arousal/stress levels with each acoustic environment. The results of the study may provide context to effectively utilize background noise in open-plan offices.
Parking lot noise evaluation
Authors: Barnobi Christopher L. , Burke Connor , Leech Jonathan
Published: November 2017

Parking Lot noise is regularly evaluated for CEQA noise assessments, but a standardized method has not been generally adopted. This paper presents sound level measurements of common parking lot activities. Other published sound level data for parking lot activities is provided to further solidify typical parking lot sound levels. A review of published methods for evaluating parking lot noise is summarized. The appropriateness of the methodology is evaluated and a simplified methodology is presented based on the similarities and differences applicable to California for CEQA analysis and the United States in general.
A preliminary look at the acquisition of acoustic field data using selected smartphone apps
Authors: Lentz Jennifer , Logan Roger M.
Published: November 2017

Numerous smartphone applications exist that measure sound levels in the acoustic field. In some cases, these apps also provide additional acoustic data in the form of real-time spectral analysis. Yet, very few studies exist that have evaluated the validity of these apps for sound level measurement. Notably, these studies evaluated performance in the laboratory and only assessed the accuracy of the measurement of sound levels. Here, we present field-acquired data on the accuracy of dB level measurement and spectral analysis of a variety of smartphone apps for both Android and iOS platforms. We then discuss the feasibility of using these applications for field data acquisition.
Subject-specific anatomical assessment of the human tongue in amyotrophic lateral sclerosis (ALS) by high-resolution MRI and diffusion tensor imaging
Authors: Lee Euna , Xing Fangxu , Ahn Sung , Reese Timothy , Wang Ruopeng , Green Jordan , Atassi Nazem , Wedeen Van , El Fakhri Georges , Woo Jonghye
Published: November 2017

Amyotrophic Lateral Sclerosis (ALS) is a progressive and irreversible neurological disorder, which affects upper and lower motor neurons in the motor cortex that control voluntary movements including speech and swallowing. High-resolution MRI (hMRI) and Diffusion Tensor Imaging (DTI) can provide non-invasive imaging of three-dimensional muscle anatomy and fiber myoarchitecture such as fiber orientation within the human tongue, respectively. In this work, we aim to assess anatomical differences of the tongue using both imaging methods by demonstrating the differences in quantities related to fiber connectivity for both normal and ALS subjects. We first manually delineate the genioglossus and superior longitudinal muscles on hMRI, which are aligned to each b0 image of DTI using deformable registration to provide regions of interest. We then compute fractional anisotropy and statistics about fibers connecting each pair of muscles. We apply our framework on five datasets including both normal and ALS subjects, revealing obvious quantitative degradation of muscle fibers in ALS patients compared to that in controls within and between muscles. Our framework has the potential to provide insight regarding the detrimental effects of ALS on speech and swallowing when combined with tongue motion data.
Not all /r/s and /l/s are the same: Classification of errors in children with cochlear implants versus normal hearing
Authors: Conover Laura , Bahr Ruth
Published: November 2017

Purpose: As children acquire speech sounds, they progress from clear substitutions, to “intermediate forms” (covert contrasts), to adult-like productions. However, there is evidence that this progression may be different in CI users as compared to NH children. Identification of intermediate forms is dependent upon rating scales that are sensitive to fine phonetic detail, such as visual analogue scales (VAS). This study uses both traditional VAS and a new 3-dimensional rating scale to explore differences in the /r,l/ productions of young children with and without hearing loss. Methods: Correct and error productions of /r,l/ were extracted from a standardized articulation test for nine congenitally deafened children who received cochlear implants (CIs) prior to age 3 and their speech age-matched controls. Stimuli were shortened to nonsense syllables to prevent real-word bias. Listeners rated these productions on both a VAS and a triangular scale, which allowed listeners to rate phone quality as a multi-dimensional function of /r/, /l/, and /w/. Results & Conclusions: Both rating scales were sensitive to subtle acoustic differences in speech sounds. Listener responses suggested more variability in sound production within the group of CI users. Listeners preferred the triangular scale because it provided greater response sensitivity.
Tongue- and jaw-specific contributions to increased vowel acoustic contrast in response to slow, loud, and clear speech in talkers with dysarthria
Authors: Mefferd Antje
Published: November 2017

Slow, loud, and clear speech can elicit increased acoustic vowel contrast in talkers with dysarthria. However, articulator-specific changes in response to these speech modifications and their relative contribution to vowel acoustic changes remain poorly understood despite the fact that these three speech modulations are commonly used as speech treatments to increase intelligibility in dysarthria. This preliminary study examined tongue and jaw movements in talkers with Parkinson’s disease (PD) and amyotrophic lateral sclerosis (ALS) using electromagnetic articulography. Participants repeated the phrase “See a kite again” five times under four speech conditions: typical, slow, loud, and clear speech. Tongue movements were decoupled from the jaw to determine the relative contribution of the jaw and tongue to the overall tongue composite movement during the diphthong /ai/ in “kite”. In the acoustic signal, the F2 minimum during /a/ and the F2 maximum during /i/ and their corresponding F1 values were extracted to calculate acoustic vowel contrast in F1-F2 vowel space. Linear regression analyses were used to determine tongue- and jaw-specific contributions to acoustic vowel contrast changes in response to these speech modifications. Data analysis is currently underway. We hypothesized that talkers with PD and ALS demonstrate different response patterns to these speech modifications.
Dispersion correction for acoustic borehole logging data
Authors: Assous Said , Elkington Peter
Published: November 2017

Compressional and shear formation velocities are key to the prediction of petrophysical properties from seismic attributes. In fast formations shear velocity may be obtained from monopole source, but in slow formations, it is commonly determined from the flexural mode associated with dipole excitation, which is a dispersive borehole-guided mode who’s low frequency and high frequency asymptote to the formation S-velocity, and to the Scholte-velocity, respectively. The shear slowness is commonly computed from well log dipole flexural mode data using Semblance Time Coherence (STC) processing. Dispersion is handled by restricting the waveforms spectral content to the low frequencies that travel close to the formation’s shear velocity. This restricting may not eliminate the need for a residual dispersion correction. Inversion addresses this difficulty by computing shear slowness directly from observed dispersion characteristics. In order to make the inversion efficient the iterative steps which compare observed and forward modeled dispersion curves are replaced with a neural net trained on a large number of pre-modeled curves generated with known formation and borehole properties. Automated mode frequency detection constrains the bandwidth over which dispersion curves are matched. Results from 127,000 modelled and field data points show improved accuracy and precision relative to STC processing.
Analysis of bats’ gaze and flight control based on the estimation of their echolocated points with time-domain acoustic simulation
Authors: Banda Taito , Sumiya Miwa , Yamamoto Yuya , Yamada Yasufumi , Nagatani Yoshiki , Araki Hiroshi , Kobayasi Kohta I. , Hiryu Shizuko
Published: November 2017

Bats detect objects by echolocation. With those echoes, they can describe the shape of objects as well as position, and then approach or avoid them. To reveal which part of objects bats gaze at, we simulated the echoes that bats hear, and estimate the bats’ echolocated points by time-domain 2D-acoustic-simulation based on the behavioral data during obstacle-avoiding flight. First, we constructed a microphone array system in an experimental chamber and attached telemetry-microphones to Japanese horseshoe bats. With that measurement system, we obtained the timing, positions and directions of emitted pulses during obstacle-avoiding flight. Using these data, we simulated the echoes returning from the obstacles (acrylic boards) and investigated how the bats show spatial and temporal changes in the echolocated points of objects as they became familiar with the space. In a comparison between before and after the habituation in same obstacle layout, there are differences in the wideness of echolocated points on objects. By flying same layout repeatedly, their echolocating field become narrower. This study suggests the help of acoustic simulation to understand the way bats see the world. [This research was supported by Scientific Research on Innovative Areas of JSPS, and the JST PRESTO program.]
Integration of dynamic emission and reception in the biosonar system of horseshoe bats
Authors: Sutlive Joseph , Riquimaroux Hiroshi , Müller Rolf
Published: November 2017

Bats have evolved unique mechanisms by which to navigate and hunt in their environments. Some species of the microchiroptera, such as members of the horseshoe bat family (Rhinolophidae), which live in particularly challenging, cluttered environments, have been observed to move their peripheral structures for emission and reception (noseleaf and pinna) during echolocation very rapidly, e.g., within a tenth of a second. With these behaviors, the bats could create time-variant properties in their biosonar systems to provide additional degrees of freedom to be used for enhancing the encoding of sensory information. To make full use of this opportunity, a tight sensorimotor integration is likely to be required. In order to explore the possible role of sensorimotor integration in a dynamic biosonar system, we have developed biomimetic robotic models to replicate the effects of the dynamics of the baffle structures. Data obtained with these systems indicates that a coordinated emitter and receiver dynamics can both contribute to the embedding of time-variant signatures in the signals that encode information about target class. Ongoing research seeks to transition insights from work on the biomimetic design paradigms to data from brain recordings made in from the auditory brainstem and the superior colliculus of horseshoe bats.
Central and peripheral nervous system modulation using ultrasound
Authors: Konofagou Elisa
Published: November 2017

Focused ultrasound (FUS) neuromodulation has previously been proposed as a promising technique to drive neuronal activity and has been shown throughout a breadth of applications including in mice, rats, non-human primates, and humans as a novel technique for the noninvasive manipulation of neuronal activity using ultrasound. Our group has demonstrated excitation of both the central (CNS) and peripheral nervous system (PNS). In the CNS, motor- and cognitive-related brain regions of mice were induced by targeting specific brain structures. Higher acoustic pressures increased the success rate. Pupil dilation was observed when neuromodulating regions in the brain covering the superior colliculus and other anxiety-related structures such as hippocampus and locus coeruleus. In the PNS, we showed for the first time stimulation of the sciatic nerve with FUS eliciting a physiological motor response was recorded in vivo. Clipping the sciatic nerve downstream of stimulation eliminated EMG activity during FUS stimulation. Peak-to-peak EMG responses and delay to signal were comparable to conventional electrical stimulation methods. Histology along with behavioral and thermal testing did not indicate damage to the nerve or surrounding regions. Our studies demonstrated the capability of FUS to modulate target specific regions in both the brain and the peripheral in vivo.
Soundscapes in historic urban environments—A case study
Authors: Jordan Pamela
Published: November 2017

In current soundscape practice, soundscape descriptors tend to focus on present conditions, either toward an assessment of site conditions or as predictive tools for future interventions. But does the same approach work when the acoustic environment reflects the past as well, such as at historic sites? How does the complexity of a place representing both past and present inform visitors’ reactions to the soundscape? Results from a recent study at the Berlin Wall Memorial will be presented, where a guided soundwalk, informed by archival accounts of the area, was combined with a survey to scrutinize visitor impressions of the soundscape in conjunction with the site’s sonic past. Descriptors common to soundscape studies were used in semantic scales alongside new proposals aimed directly at understanding the role that historic information plays in assessments by visitors and local experts. Results from the study will be presented, showing how historic information can subvert some of our fundamental assumptions about soundscape, such as what constitutes “appropriate” or “pleasant” conditions, and how results may differ across expert groups. Indeed, this research demonstrates the powerful impact that historic context can exert on soundscape assessment, with implications for soundscape practice, heritage interpretation, and urban planning alike.
Sensitivity to sounds produced in the city, sound ordinance issues, and cultural planning in New Orleans
Authors: Stryckman Helene , Woolworth David
Published: November 2017

In an effort to address sound ordinance issues and better quantify and qualify the soundscape of New Orleans, multiple soundwalks have been held in the older areas of the city over the last few years, specifically in the densest tourist areas (Vieux Carre/French Quarter and Marigny). Sound level data and participant response from several soundwalks are considered with respect to age, sex, occupation, stakeholder status, and language of descriptive used by the respondents. This soundscape inquiry technique has been complemented by qualitative ethnographic fieldwork performed in 2015 that describes the sound ordinance issues and the communities historically involved: musicians, music venues owners, cultural advocates, newcomers, and neighborhood associations. This qualitative case study reveals a process-based dynamic that evolves around different stakeholders’ sensitivity to sounds produced in the city. We propose that a sound ordinance should attempt to be neutral in regard to cultural effects and be based on the community-asset knowledge of local experts.
Statistical characterization of sound propagation along near-vertical paths in a turbulent atmosphere
Authors: Ostashev Vladimir E. , Wilson D. Keith , Hart Carl R.
Published: November 2017

Most previous research on sound propagation in the atmosphere has focused on nearly horizontal propagation paths, with the sources and receivers close to the ground. Along such paths, refraction by wind and temperature gradients, and scattering of sound by small-scale turbulence, are known to be important and have been studied extensively during the past couple decades. Sound propagation from elevated sources is fundamentally different because the atmospheric motions are larger, more coherent, and driven by different types of instabilities. The corresponding research is needed to address the ability of ground-based acoustic microphone arrays to detect and track elevated sound sources, as well as the ability of elevated arrays to detect and localize ground-based sources. In this paper, near-vertical sound propagation through a turbulent atmosphere is studied using approaches and methods developed in wave propagation through random media. The statistical characteristics of sound signals for near-vertical propagation such as the log-amplitude and phase fluctuations, angle-of-arrival variance, transverse and longitudinal spatial coherence, and temporal and frequency coherence are calculated and analyzed. The results obtained are compared with those for near-horizontal sound propagation.
Background noise interacts with spectral context effects during speech categorization
Authors: Stilp Christian
Published: November 2017

Speech perception is heavily influenced by surrounding sounds. When spectral properties differ between earlier (context) and later (target) sounds, this can produce spectral contrast effects (SCEs) that bias categorization of later sounds. For example, context sounds with a low-F1 bias produce more high-F1 responses to the target vowel and vice versa. SCEs have been studied for decades but only for speech perception in quiet. Background noise is expected to interfere with these effects, but the extent of this interference is unclear. On each trial, listeners heard a context sentence and target vowel both combined with speech-shaped noise. Sentences were filtered to add a + 20-dB spectral peak at low-F1 (100–400 Hz) or high-F1 frequencies (550–850 Hz). Target vowels varied from /ɪ/ to /ɛ/. Background noise was unmodulated or sinusoidally modulated at 2/4/8 Hz at variable SNRs. In general, SCEs were larger at better SNRs and in unmodulated noise, but all SCEs were smaller than those reported for speech in quiet. Complex patterns of results were observed at different noise modulation rates, with likely ties to modulations in F1 frequency regions in the context sentence. In sum, background noise diminishes context effects in speech perception, but the extent depends on noise characteristics.
Sweat Sodium, Potassium, and Chloride Concentrations Analyzed Same Day as Collection Versus After 7 Days Storage in a Range of Temperatures
Authors: Baker Lindsay B. , Barnes Kelly A. , Sopeña Bridget C. , Nuccio Ryan P. , Reimel Adam J. , Ungaro Corey T.
Published: November 2017

The purpose of this study was to determine the effect of storage temperature on sodium ([Na+]), potassium ([K+]), and chloride ([Cl−]) concentrations of sweat samples analyzed 7 days after collection. Using the absorbent patch technique, 845 sweat samples were collected from 39 subjects (32 ± 7 years, 72.9 ± 10.5 kg) during exercise. On the same day as collection (PRESTORAGE), 609 samples were analyzed for [Na+], [Cl−], and [K+] by ion chromatography (IC) and 236 samples were analyzed for [Na+] using a compact ion-selective electrode (ISE). Samples were stored at one of the four conditions: −20 °C (IC, n = 138; ISE, n = 60), 8 °C (IC, n = 144; ISE, n = 59), 23 °C (IC, n = 159; ISE, n = 59), or alternating between 8 °C and 23 °C (IC, n = 168; ISE, n = 58). After 7 days in storage (POSTSTORAGE), samples were reanalyzed using the same technique as PRESTORAGE. PRESTORAGE sweat electrolyte concentrations were highly related to that of POSTSTORAGE (intraclass correlation coefficient: .945–.989, p < .001). Mean differences (95% confidence intervals) between PRESTORAGE and POSTSTORAGE were statistically, but not practically, significant for most comparisons: IC [Na+]: −0.5(0.9) to −2.1(0.9) mmol/L; IC [K+]: −0.1(0.1) to −0.2(0.1) mmol/L; IC [Cl−]: −0.4(1.4) to −1.3(1.3) mmol/L; ISE [Na+]: −2.0(1.1) to 1.3(1.1) mmol/L. Based on typical error of measurement results, 95% of the time PRESTORAGE and POSTSTORAGE sweat [Na+], [K+], and [Cl−] by IC analysis fell within ±7–9, ±0.6–0.7, and ±9–13 mmol/L, respectively, while sweat [Na+] by ISE was ±6 mmol/L. All conditions produced high reliability and acceptable levels of agreement in electrolyte concentrations of sweat samples analyzed on the day of collection versus after 7 days in storage.