bluuebunny/crossref_metadata_2025 huggingface dataset:
Age-related differences in modulation detection interference and interference release
Authors: He Yuan , Lentz Jennifer
Published: April 2019

Age-related declines have been observed in auditory tasks related to temporal processing, but less work has been conducted in middle-aged listeners and in auditory sound segregation tasks. This experiment addresses these issues by evaluating modulation detection interference (MDI) and release from MDI using streaming in young, middle-aged and older listeners. Using a standard MDI paradigm, we measured amplitude modulation detection thresholds of a high-frequency tone in different conditions: in quiet, in the presence of a low-impact unmodulated interferer, and in the presence of a high-impact modulated interferer. Then, we measured streaming-based release from MDI using four modulated precursors designed to perceptually capture the interferer and therefore reduce the amount of interference. Preliminary data suggest that middle-aged normal-hearing listeners experience similar MDI to young listeners and also receive a large release from interference when precursors are present. Additional data will be presented from older listeners, who experience slightly greater MDI than younger listeners.
Surveying the sounds used in the Journal of the Acoustical Society of America (1950–2017)
Authors: Schutz Michael , Gillard Jessica
Published: April 2019

The earliest auditory psychophysical experiments involved naturalistic sounds such as hammers striking plates. The subsequent development and ubiquity of desktop computing gave researchers the ability to more precisely control stimulus parameters such as frequency, amplitude, and duration (Neuhoff, 2004). However much of our everyday listening is for events rather than easily manipulated properties (Gaver, 1993), and the world lacks the kinds of constrained sounds often used in auditory research (Phillips et al., 2002). Although simplistic auditory stimuli hold benefits with respect to control, their disproportionate use poses problems for generalizing outcomes from key experiments. To provide insight into the sounds used in auditory perception research, we surveyed a representative sample of auditory stimuli from 217 psychophysical experiments published in JASA between 1950 and 2017. Our survey documents a disproportionate focus on simplistic sounds, with less than 4% of psychophysical experiments using stimuli exhibiting the dynamic temporal structures characteristic of natural auditory events. We will discuss the implications of these findings in the content of ongoing areas of inquiry of broad relevance to the auditory perception community.
Measured localization performance at low stimulus levels with an adaptive tracking task
Authors: Spencer Nathaniel , Thompson Eric R. , Simpson Brian
Published: April 2019

Sabin et al. (2005) measured localization accuracy for 250-ms broadband noises that varied in location along a spherical surface, and varied in stimulus level, from 0 to 60 dB above the detection threshold. They found that, for lower stimulus levels, responses tended to be biased towards lower elevations and to the front, and were more accurate at higher stimulus levels. Whereas Sabin et al. (2005) randomized level and location between trials, the current study fixed location and increased level until a correct response was given (or the 80 dB SPL limit was reached). Our initial level was 12.5 dB SPL, and our step size 2.5 dB SPL. Responses tended to be biased towards lower vertical elevations and to the front at low stimulus levels, and be more accurate at higher levels, consistent with Sabin et al. The percentage of front/back errors was generally greater for locations in the rear hemifield relative to those in the frontal hemifield, and for locations at higher elevations relative to locations at lower elevations. Audibility analysis, performed using a KEMAR manikin, showed that localization errors tended to decrease the most when audible bandwidth increased at the acoustically better ear.
Measuring anisotropy in underwater inertial metamaterials
Authors: Cushing Colby W. , Wilson Preston S. , Haberman Michael R. , Shen Chen , Cummer Steven
Published: April 2019

The acoustic behavior of acoustic metafluids, designed and fabricated for underwater applications has been studied experimentally. Unit cells consist of elastic elements coupled via compliant layers to produce negligible shear modulus and anisotropic dynamic effective density and phase speed in orthogonal directions. Finite element simulations were used to design a unit cell that exhibits subsonic phase speeds in one direction and supersonic speeds in the orthogonal direction. Numerous samples were constructed to experimentally validate these predictions. Various combinations of materials were employed to enhance anisotropy, simplify construction, and reduce unwanted effects. Uniformly-spaced samples were tested from 0.05-10 kHz in a one-dimensional, resonator tube filled with degassed water. An electrodynamic shaker excited the system with frequency-modulated chirps. The system response was recorded using a hydrophone positioned near the top of the tube, and the resonance frequencies were used to infer the phase speeds for each mode. To extract material properties from these measurements, an effective medium model was used to represent the material-water mixture and an exact analytical dispersion relation was used to correct for elastic waveguide dispersion. Extracted material properties indicated anisotropy was achieved, and were found to be in good agreement with the as-designed properties. [Work supported by ONR.]
Multiplicity of coprime pairs for extension of coprime sensor arrays
Authors: Johnson Pablo , Sartori Daniel , Trosclair Tyler , Willis John , Adhikari Kaushallya
Published: April 2019

This research finds the optimum period of a basic coprime sensor array (CSA) needed to reduce the PSL height to -13 dB for both minimum and product processing methods. Our design does not have the constraint that the subarray lengths be one integer apart unlike in [Adhikari et al., 2014]. We apply MUSIC algorithm to the optimized CSA and compare the PSD estimate obtained by Vaidyanathan and Pal’s covariance matrix estimation using a single sensor pair versus our covariance matrix estimated using all available sensor pairs. We show that minimum processing requires fewer periods than product processing to reach the PSL height of -13 dB. Larger coprime pairs require fewer periods and cause an increase in variance and a decrease in the number of lags available between the two subarrays. This decrease lowers the accuracy of the covariance matrix estimation. However, using all available sensor pairs to generate the covariance matrix greatly increases the accuracy compared to using a single sensor pair. When only one signal is present, both covariance estimates produce a similar, accurate DOA, but as the number of signals increases, our covariance estimate performs better. [Work supported by Louisiana Tech University.]
MVDR beamforming using one bi-axial velocity-sensor
Authors: Song Yang , Wong Kainam T.
Published: April 2019

A bivariate velocity-sensor measured two Cartesian components of the acoustic particle velocity field, which represents the spatial gradient of the acoustic pressure field. One such bi-axial unit provides azimuth-polar two-dimensional spatial directivity. This work presents the MVDR beam-pattern for such a sensing unit.
Bat biosonar echo analysis using spatial audio and wideband matched-filter techniques
Authors: Lee Hyeon , Ming Chen , Roan Michael J. , Simmons James A.
Published: April 2019

Bats and dolphins show tremendous aptitude in hunting prey in difficult conditions. These conditions include large amounts of clutter, perhaps reverberation, and interfering signals/noisy backgrounds. Bats have been extensively studied to learn more about how they detect, track, and intercept prey. One important aspect of many of these studies is to understand the acoustics around the bat’s head. In this work, a new reproduction methodology using spatial audio and matched-filter techniques will be presented. A custom-built tetrahedral 1st order soundfield microphone that captures high-frequency sound up to 80 kHz from all directions was developed to measure bat echoes in B-format. The three-dimensional echoes that the bat received, now in Ambisonic B-format were further processed using a wideband matched-filter. The matched-filter produces a wideband cross-ambiguity function (WAF) of received data and the transmitted signal for every 1 deg in azimuth and elevation. The thresholded matched-filter output provides precise estimates of bearing, elevation, range, and normal velocity. This poster will present details of the hardware and software development along with experimental results that illustrate the capabilities of this new approach.
University of Colorado, Colorado Springs—Ent center for the arts
Authors: Nichols Matt
Published: April 2019

The UCCS Ent Center for the Arts is a transformational five-venue center; an innovative collaboration involving the university, six community arts partners and three local school districts. Jaffe Holden provided acoustic and audio/video systems design services for a wide range of spaces including a multi-use hall, recital hall, art gallery, drama theaters, art lab, recording studio, music rehearsal room, teaching studios and practice rooms. Our acoustic focus within the Shockley-Zalabak Theater was on making a successful multi-use hall to support a wide range of programming including full orchestra ensembles and small chamber groups. The acoustic response can be adjusted by a motorized system of drapes and acoustic banners concealed above a partially sound-transparent ceiling. A stage lift allows changes to be made to seating configuration and provides a stage extension. An acoustical shell can be configured to accommodate both large and small group performance. The Chapman Foundation Recital Hall’s acoustics can also be tailored to suit various musical ensembles, thanks to an adjustable acoustic curtain system hidden above the partially sound-transparent ceiling and slatted wood wall at the rear of the stage. One of the biggest challenges was to successfully isolate a dance studio directly above a recording studio control room.
Design and manufacturing of a miniature pneumatic actuator for a bat robot
Authors: Sullivan Kent , Conk Matthew , Eckman Emmet , Lunsford Sierra , Martin Charlie , Singh Agoshpreet , Wang Yanhao , Sutlive Joseph , Müller Rolf
Published: April 2019

There have been many pneumatic actuator designs created over the past several years. One such design consists of multiple, completely separated air cells that when pressurized, expand and push off one another causing the actuator to bend. With this chamber design, the actuator requires a small change in volume to deform, effectively leading to improved reliability and increased actuation speed. Other design characteristics such as cross section geometry, inner/outer wall thickness ratio, distance between cells, cell height, and material selection can be modified to optimize the actuator’s performance. Incorporating this design into the bat robot allowed for greater soft robotic ear deformation, however it is too large for this application. To see if it was possible to reduce the size of the actuator while maintaining its functionality, several adjustments were iteratively made to previously described mold designs. Manufacturing remained a two-step process, but removable side walls and a filter-ventilation system were added to allow for the silicone, used to cast the actuator, to fully cure. Ultimately, the actuator produced maintained its expected functionality and was produced at a smaller scale than originally thought possible.
Sonar signal representation mimicking the inner ear of horseshoe bats
Authors: Khyam Mohammad Omar , Bhardwaj Ananya , Alexandre David , Müller Rolf
Published: April 2019

Current models of the initial stages of auditory processing in mammals usually agree that the input signals are split into a bank of bandpass filters. However, the available models differ substantially in their level of complexity and the number of parameters needed. In the current work, the varying levels of complexity in filterbank models of the basilar membrane have been evaluated in the context of modeling the cochlear processing of natural biosonar echoes in horseshoe bats. To this end, three different types of filterbank models have been implemented to represent the range of complexity spanned by models that are in use for the human inner ear: The simplest model, a gammatone filterbank, is a linear model with symmetric filter transfer functions. The gammachirp filterbank is also linear, but mimics the asymmetric transfer functions of the basilar membrane. Finally, the dual resonance nonlinear (DRNL) model adds a level-dependent behavior. Here, all three models have been adapted to the specifics of the basilar membrane of horseshoe bats which is characterized by an “auditory fovea” with exceptionally high filter qualities. The outputs of the different models have been encoded into a sequence of neural spike times before being evaluated with various information-theoretic methods.
Accommodating constraints for modeling of biosonar processing by big brown bats
Authors: Ming Chen , Simmons James A. , Haro Stephanie , Gaudette Jason E.
Published: April 2019

Constraints on modeling of wideband FM biosonar are acoustic (small targets return discrete replicas of the incident sound from individual component parts), auditory (inner-ear transduction segments broadcasts and echoes into numerous, parallel bandpass channels with integration-times of ~350 μs), neural (processing retains parallel frequency bands throughout the auditory pathway that use single spikes to mark frequencies), and perceptual (bats nevertheless perceive true delays of individual glint reflections, not just spectral coloration). The bat’s target model is geometric, registering the glints binaurally along the range axis. However, because closely-spaced glints are represented by their mutual interference, not by separate acoustic reflections, the ripples have to be transposed from an interference pattern back into glint delay estimates. Auditory cortical neurons selective for specific patterns of ripple come to register instead the underlying time separation of the glint reflections. The developing SCAT model of wideband FM biosonar incorporates a network for glint delay transformation that also offers a route for clutter suppression by contrasting dispersed, unfocused clutter images with tightly focused target images in range and azimuth space. The feedforward inhibition of this network preserves real-time operation for target reconstruction as well as for guidance in clutter. [Work supported by ONR.]
Biomimetic foliage echo simulation
Authors: Goldsworthy Michael , Müller Rolf
Published: April 2019

Many echolocating bat species are capable of navigating through highly cluttered environments, such as dense foliage—apparently without difficulty. Since interpreting foliage echoes must hence be key to the animals' navigation capabilities, simulating such echoes would be a major step towards understanding bat navigation. This is a difficult task, as vegetation echoes are highly complex and stochastic signals. Prior work on modeling foliage echoes frequently relied on physical approximations, since full physics models are computationally infeasible. For simulating the echo from a leaf, a round disk approximation has been used, since it’s echo has a known physical solution. These disks have been distributed according to the locations of leaves in a tree using a Lindenmayer System (L-System), thus creating a full tree echo model. Successful prior work in using a machine learning approach for echo based tree classification, shows that a data driven approach may also be useful in modeling echoes. Hence, future research will be using machine learning methods, such as auto-encoders and generative adversarial networks, to simulate the echoes of leaves and trees. The echo data to be fed into these methods will be of leaves recorded in an anechoic chamber using a biomimetic sonar head.
Lipid-shelled microbubbles for ultrasound-triggered release of bioactive gases to treat stroke and cardiovascular disease
Authors: Holland Christy K. , Shekhar Himanshu , Lafond Maxime
Published: April 2019

Ischemia-reperfusion-induced neurological injury is a primary cause of stroke disability. Xenon (Xe), a bioactive gas, has potential as an effective and nontoxic neuroprotectant for the treatment of ischemic stroke. Nitric oxide (NO) is a potent bioactive gas capable of inducing vasodilatory, anti-inflammatory, neuroprotectant and bactericidal effects. The goal of this work was to develop lipid-shelled microbubbles for site-specific release of Xe or NO upon pulsed ultrasound exposure. Gas-loaded microbubbles were synthesized by high-shear mixing of a lipid dispersion in a vial that contained, Xe or NO, and octafluoropropane (OFP) in combination. Attenuation spectroscopy measurements demonstrate the feasibility of 6-MHz pulsed Doppler ultrasound-triggered release of Xe or NO from microbubbles. The addition of OFP in the lipid-shelled microbubbles increased the number density, size, and stability of the microbubbles, particularly in undersaturated saline. Gas chromatography mass spectrometry was employed to measure Xe dose (127 ± 29 μl Xe/mg lipid). The payload of NO in the microbubbles (97 ± 12 μl NO/mg lipid) was assessed using an amperometric sensor. Intravenous administration of microbubbles carrying a neuroprotective or a vasodilatory gas in combination with ultrasound exposure has potential as a novel noninvasive strategy for local therapeutic delivery to modulate the effects or duration of cerebral ischemia.
Detection of nucleic acid-loaded microbubbles in mouse hearts during ultrasound-mediated delivery
Authors: Campbell Meghan R. , Priddy Mariah C. , Kopechek Jonathan A.
Published: April 2019

Heart disease is a leading cause of death worldwide. Recently, there has been a growing interest in nucleic acid-based therapeutics, such as microRNAs (miRs) or microRNA inhibitors (antimiRs), for cardiac repair. Previous studies have shown that regulating microRNA levels in the heart can promote proliferation of cardiac cells, decrease fibrosis, and improve cardiac function. Ultrasound targeted microbubble destruction (UTMD) is in development to focus the delivery of therapeutic nucleic acids to the heart and reduce adverse systemic effects. Microbubbles can be loaded with nucleic acids and exposed to ultrasound in order to induce cavitation and enhance delivery at the target site. In this study phospholipid-coated microbubbles were loaded with therapeutic miR mimics or antimiRs and injected intravenously in mice. Ultrasound pulses (2.5 MHz, 0.9 MPa peak negative pressure) were applied to the heart using a P4-1 array on a Verasonics Vantage ultrasound system. The ultrasound images were analyzed to detect microbubbles in the heart during treatment. Increased mean intensity during infusion was associated with increased delivery of nucleic acids to the heart as assessed with qPCR. The results suggest that quantitative analysis of ultrasound images to detect microbubbles in vivo may aid in monitoring UTMD treatment for improved cardiac health.
Design of a focused ultrasound transducer for histotripsy-thrombolytic combination therapy
Authors: Maxwell Adam D. , Haworth Kevin J. , Holland Christy K. , Bader Kenneth B.
Published: April 2019

Chronic thrombus components are resistant to removal by current interventional techniques and can act as thrombogenic sources. Histotripsy is a focused ultrasound therapy that utilizes the mechanical activity of bubble clouds to liquefy target tissues. In vitro experiments have demonstrated histotripsy provides enhancement of the thrombolytic agent recombinant tissue plasminogen activator in a retracted clot model representative of chronic thrombus. Although these in vitro results are promising, further refinement of the acoustic source is necessary for in vivo studies and clinical translation. To define the source parameters for use in vivo, a design study was conducted with transcutaneous exposure of porcine and human iliofemoral deep venous thrombosis (DVT) as the target. Design parameters were selected to confine the focus, and thus bubble activity, within the femoral vein of DVT patients. Furthermore, the therapy array accommodates the placement of a confocal diagnostic linear array for image guidance. Based on the design criteria, a 1.5-MHz elliptical source with 6-cm focal length and a focal gain of 70 was selected. Details of the design, fabrication, and characterization the source will be presented, as well as the means by which bubble activity is initiated.
Intrinsic threshold versus shock scattering histotripsy treatment of clots in vitro
Authors: Bollen Viktor , Haworth Kevin J. , Maxwell Adam D. , Holland Christy K. , Bader Kenneth B.
Published: April 2019

Catheter-directed thrombolytics are the frontline therapy for iliofemoral deep vein thrombosis. We have demonstrated that histotripsy can enhance the efficacy of the thrombolytic recombinant tissue plasminogen activator (rt-PA) through the mechanical activity of bubble clouds. Depending on the histotripsy pulse duration, bubble activity can be initiated via shock wave scattering or exceeding the peak negative pressure of the intrinsic cavitation threshold. In this study, the thrombolytic efficacy and bubble activity of shock scattering and intrinsic threshold histotripsy were compared. The mass loss was assessed of retracted human whole blood clots exposed to rt-PA (0 or 2.68 μg/mL) and histotripsy pulses of 1 (intrinsic threshold) or 5 (shock scattering) cycles duration. During the histotripsy exposure, bubble cloud emissions were captured on a linear array and processed to form passive acoustic images. The combination of rt-PA and histotripsy was more efficacious than rt-PA alone at 25 MPa peak negative pressure for single-cycle pulses, and 20 MPa peak negative pressure for five-cycle pulses. The degree of thrombolytic efficacy correlated with bubble cloud emissions within the clot. Overall, these results indicate that rt-PA and shock scattering or intrinsic threshold histotripsy is a promising combination thrombolytic therapy.
Nonlinear acoustics of complex solids and granular media
Authors: Tournat Vincent
Published: April 2019

This talk is an introduction to nonlinear acoustic processes in complex solids such as cracked metals, damaged composites or concrete, and granular media. These materials, belong to the same class of complex solids often referred to as mesoscopic solids, and share a number of similar nonlinear acoustic behaviors originating mainly from the presence of internal solid contacts. The specific nonlinear acoustic signatures and processes will be described (slow dynamics, memory, contact acoustic nonlinearity, i.e. nonclassical nonlinearities) through several examples, and an overview of the main modeling tools will be provided. Finally, the current trends and several applications of such nonclassical nonlinear processes (nondestructive testing and characterization, wave control, etc.) will be given.
On the utility of C/S as an indicator of nonlinearity in finite-amplitude dispersive waves
Authors: Park Taeyoung , Ohm Won-Suk , Gee Kent L. , Reichman Brent O.
Published: April 2019

A frequency-domain nonlinearity indicator C/S, recently introduced by Ohm et al. [Proc. Mtgs. Acoust. 29, 045003 (2016)], is a companion indicator to the well-known Morfey-Howell Q/S [AIAA J. 19, 986–992 (1981)]. The two indicators can be regarded as “two sides of the same coin,” because C/S and Q/S are, respectively, defined by the real and imaginary parts of the cross-spectrum of the pressure and squared-pressure waveforms. Despite the common origin, however, C/S and Q/S describe the pertinent nonlinear wave process in a different light. Furthermore, for nonlinear waves in media with strong dispersion only C/S may be applicable, because the use of Q/S could lead to erroneous interpretations. In this paper, we demonstrate the utility of C/S in the context of the Korteweg-de Vries (KdV) equation, which is one of the most celebrated model equations for nonlinear waves in dispersive media. The success of C/S is juxtaposed with the limitation of Q/S in describing nonlinear dispersive wave processes, especially in the case of solitons.
Direct detection of dark matter particles by nonlinear effects in crystal vibrations
Authors: Ostrovskii Igor
Published: April 2019

The energetic dark matter particles (EDP) of (4 + 1.5) x 1015 eV mass-energy propagating from the central region of the Milky Way galaxy (CMW) are directly detected with the help of half-inch ~10 MHz quartz vibrators. The spectra of acousto-electric vibrations of thin piezoelectric crystal are theoretically calculated, and a nonlinear effect of external frictional influence is taken into account. The EDP produce the changes in the spectra of vibrations under specific orientation of the crystallographic axes toward the CMW. The mechanism of EDP-crystal interaction may be associated with the gravitational influence of EDP and their quantum properties, such as matter waves. The EDP average energy density is 0.71 + 0.29 (GeV/cm3) near Earth, which agrees with the expectations and existing astrophysical bounds of dark matter density in the solar neighborhood. The EDP can transfer their momenta-energy to a media of propagation. The influences of EDP, or naviten, on vibrating atoms are detected from 10 different samples during 5 years. The micro-void tracks of EDP-particles are also observed in the vibrating plates of fuzzed quartz, which appear due to EDP decay inside solid media. The existence of EDP-particles is in agreement with recent detection of the ~1015 eV energy neutrinos from the CMW region.
“Straightness” versus “briefness” in binaural cue extraction
Authors: Stecker G. Christopher , Dietz Mathias , Stern Richard M.
Published: April 2019

The neural mechanisms that detect and encode interaural delays have elicited intense interest for many decades, from Jeffress’s [J. Comput. Physiol. Psychol. 41, 35–39 (1948)] original “place theory of sound localization,” its modeling via frequency-specific cross-correlation starting with Colburn [JASA  54, 1458–1470 (1973)], and continuing to this day. An important advance was the emphasis of cross-correlation peaks that align across frequency [“straightness” ; Stern et al., JASA 84, 156–165 (1988)]. While narrowband cross-correlation produces multiple peaks and is therefore inherently ambiguous, straightness detection accounts for resolution of that ambiguity in broadband stimuli by combining binaural outputs across frequency. An alternative account is suggested by the effects of temporal fluctuations, such as onsets, on the inputs to binaural processing. Zurek [JASA 67, 953–964 (1980)] described how emphasizing such events (e.g., by “windowing” the input) also resolves interaural ambiguities. Recent psychophysical and physiological evidence supports that view, strongly suggesting that binaural processing does, in fact, occur in brief windows triggered by envelope fluctuations such as onsets and intrinsic fluctuations in bands of noise. This talk investigates the possibility that the resulting temporal sparsity of binaural inputs (“briefness” ) might account for bandwidth effects even within single frequency channels, i.e. without a second level of “straightness” detection.
Longitudinal development of conversational exchanges in children with hearing loss
Authors: VanDam Mark , Hibben Rebecca
Published: April 2019

Conversations between adults and children have been shown to be an important factor affecting the development of cognition, academic performance, and language use in children. Conversational exchange frequency between parents and children has been shown to increase with age. It has also been demonstrated that degraded sensory input, such as with hearing loss, can result in reduced language, speech, and communication skills in children. This study examines the longitudinal development of conversational exchanges between children with hearing loss and their parents. Thirty-nine families contributed 370 daylong recordings constituting 4337 h of audio collected from a body-worn audio recorder. Automatic speech processing techniques were used to identify and tally conversational exchanges. The main longitudinal effect of age on conversation exchange rate is confirmed, but the effect is weaker and may have a different developmental trajectory for families of children with a hearing loss. This result may be influenced by differences in the development of joint attention between children who are typically developing and those with hearing loss.
Child-directed speech enhances preschoolers’ speech perception in noise
Authors: Smith Nicholas A. , Hammans Christine A. , Vallier Timothy J. , McMurray Bob
Published: April 2019

A dominant idea in research on infant-directed speech is that caregivers hyperarticulate their speech and exaggerate speech clarity as a means of facilitating language learning for infants. Much less is known about the acoustic-phonetic properties of speech to young children who are more amenable to perceptual testing. This study tests whether child-directed speech (CDS) is more intelligible by testing 4- to 6-year-old listeners in a speech-in-noise task in which they selected the corresponding picture on a touchscreen. Target words were two-way minimal pairs that contrasted in terms consonant voicing (e.g., “back” versus “pack"), vowel (e.g., “back” versus “beak"), or consonant and vowel (e.g., “back” versus “peak"). At a constant signal-to-noise ratio of -6 dB, speech recognition performance was significantly greater for CDS than for adult-directed speech (ADS). However, significant differences were also found across stimulus talkers, with some mothers providing a greater overall CDS benefit than others. Furthermore, CDS was related to greater enhancement of vowel contrasts in some mothers, and greater enhancement of consonant voicing in others. These perceptual results are discussed in terms of the acoustic-phonetic properties of these speech productions.
Average daily speech exposure for fetuses
Authors: Monson Brian B. , Cull Molly
Published: April 2019

The quality and quantity of speech and language exposure during early childhood is believed to be predictive of language ability during later childhood development. However, the human auditory nervous system comes “online” in utero, at least as early as 23 weeks’ gestation. It has been demonstrated that intrauterine fetal experience with extrauterine sounds during this last trimester of gestation is sufficient to impact auditory brain development and neural responses to speech. Whether fetal exposure to speech affects later childhood language development remains an open and difficult question. To begin to address this question, we collected and analyzed fetal auditory exposure data for sounds generated in the extrauterine environment using small audio recorders worn by pregnant women during the third trimester of pregnancy. Averaged across 2200 h of audio data, daily speech exposure for individual fetus subjects ranged from 2.8 to 5 h, suggesting some newborns may begin extrauterine life with less than 60% of the speech and language exposure of their peers. Whether this variability is associated with variability in subsequent development remains to be seen.
Context-dependent hyperarticulation of the Korean three-way laryngeal stop contrast in clear speech
Authors: Shin Seulgi , Jongman Allard
Published: April 2019

We investigate whether and how speakers’ adaptation to feedback is reflected in hyperarticulation by comparing the productions of Korean aspirated, lenis, and fortis stops in plain versus clear speech. Ten Seoul Korean speakers were asked to read a stop-initial nonword and repeat the nonword after receiving misrecognition feedback that contained a contrasting stop. f0 and VOT were examined as main cues to the Korean stop distinction. Results showed that VOT was lengthened for aspirated and lenis stops in clear compared to plain speech. This difference in VOT was attributable to speakers’ modification in response to different types of feedback. VOT for aspirated stops was lengthened after both fortis and lenis feedback whereas VOT for lenis stops was lengthened only after fortis feedback. f0 did not show a difference between plain and clear speech. However, f0 enhancement for lenis and fortis stops depended on the type of feedback. f0 for lenis stops was lowered after aspirated feedback and raised after fortis feedback. Fortis stops’ f0 was lowered after aspirated and raised after lenis feedback. Overall, speakers can make local modifications in VOT and f0 in response to specific feedback, suggesting precise control in their effort to distinguish sounds and maintain intelligibility.
Features of the protective cover of the ultrasonic imager with high resolution
Authors: Yusupov Kamil , Kosarev Victor , Akchurin Adel
Published: April 2019

This work describes the features and design of the acoustically semitransparent cover of a borehole ultrasonic imager with high resolution. This scanner is designed to investigate the fine structure of the well surface by ultrasonic sounding method at a frequency of 800 kHz. The ultrasonic transducer is rotating around a central axis. However, in the design of the device fixed semitransparent protective cover is provided for prevent damage of mechanical parts. Nevertheless, during reflected signals recording from the wall of well the undesirable noise reflections appear from protective cover. These noises interfere with the algorithm of detecting the main signal. The logging tool electronics is based on a single FPGA chip, its logic cells capacity allows determining the maximum reflection amplitude and its location, as well as recording the signal time window to the SD-card (with 32GB storage space). This windows are processed at the personal computer after logging. Such approach allows analyzing waveforms and noises. After a multiple laboratory and well experiments this logging tool was allow improving the design of the acoustically semitransparent protective cover for maximum attenuation of the reflection noise. In addition, the forms of the recorded acoustic signals and the design of the protective cover are given.
Sequential bottom parameter estimation using blind deconvolution of sources of opportunity in ocean waveguide for Santa Barbara channel experiment
Authors: Zhang Xuedong , Durofchalk Nicholas C. , Sabra Karim G. , Wu Lixin
Published: April 2019

This paper investigates the performance of sequential bottom parameter estimation based on ray-based blind deconvolution (RBD) [Sabra et al., JASA EL42-7 (2010)] of sources of opportunity using the 2016 Santa Barbara Channel (SBC) experimental recordings of shipping noise. The RBD algorithm relies on estimating the unknown phase of the source of opportunity through wideband beamforming along a well-resolved ray path to approximate the environment’s channel impulse responses (CIR) between the source and the VLA elements. The corrected power ratio of the direct and bottom-bounced arrivals is processed to infer the bottom reflection loss and is utilized to invert for the bottom parameters. Sequential parameter estimation uses a state space model for predicting and correcting the bottom parameters as the estimated bottom reflection loss values become available. Inversions results for the SBC experiment were also performed with conventional active sources to validate the inversion obtained with RBD of sources of opportunity.
Experimental study on measurement of transient sound in a reverberation tank
Authors: Tang Rui , Yu Xinyue
Published: April 2019

As a new application of reverberation tanks, the experimental study on measuring the sound energy level of transient sound sources in a reverberation tank was proposed in this paper. According to the law of energy conservation, the transient sound energy obtained by sound intensity integration in time domain, which is the same with sound energy density spectrum integration in frequency domain. By utilizing the invariant sound field correction factors, the transient sound source level could be obtained in a reverberation tank, and both the reverberant measurement methods in frequency domain and that in time domain were established. The impulsive sound and the spark sound experiments were carried out in UATL (Underwater Acoustics Technology Lab, Harbin Engineering University, China) to confirm the validity of the proposed method. Experiments results showed that the sound source level of the transient sounds could be precisely measured in reverberation tanks, and compared to free field measurement, the deviation was less than 1 dB.
Computer simulation of energy efficient speech production during locomotion over water without regular swimming strokes
Authors: Biswas Amitava
Published: April 2019

Many aquatic animals need to live extended periods of time over water without much concern for fatigue. In contrast, humans are usually prone to fatigue during locomotion over water and unlikely to sustain energy efficient production of speech simultaneously. According to computer simulations, a strategy of backfloating and articulating all four or some of the limbs like oars can move the body efficiently, and the individual is less likely to fatigue and more able to maintain uninterrupted normal speech conversation for a greater period of time. The motion can be easily directed towards the feet to avoid striking the head against an obstacle when distracted by the speech conversation.
Analysis of bioacoustics and noise pollution in the penguin exhibit at Newport Aquarium
Authors: Colaianni Julie , Scheifele Peter M.
Published: April 2019

The present study researches the acoustic habitat of the penguin exhibited at Newport Aquarium in Newport, KY by means of measuring environmental noise within their exhibit. Noise exposure has been well studied in humans by using a weighted decibel scale to provide safety guidelines for the level of noise and the maximum time one can be exposed to each level. Therefore, the same principle is being used to observe if these animals are experiencing noise pollution from their own environmental sounds. The absorption coefficients of the materials that make up the habitat were also taken into consideration during data collection. The aim of this research is to gather calculations for the time it takes for the sound pressure level to reduce by 60dB (RT60) after periods of vocalization by the colony of penguins and to determine if these reverberation values reach the peak sensitivity of hearing thresholds for them.
Irreversible shifts in optical autofluorescence spectra applied to the assessment of thermal lesion formation under high intensity focused ultrasound
Authors: Shrivastava Shamit , Everbach E. Carr , Raymond Jason L. , Roy Ronald
Published: April 2019

High-intensity focused ultrasound (HIFU) is often used to create lesions, or regions of tissue destruction due to heating and cavitation activity, most often in tumors or other diseased tissues. However, the acoustic properties of tissues denatured by heat are not very different from those of untreated tissue, making lesion detection and quantification difficult by ultrasound alone. Autofluorescence refers to the broadband emission of light within materials that are stimulated by narrowband incident light, typically from a laser. It is a common characteristic of lipids, proteins, and other biomolecules, and the “autofluorescence spectrum” is a function of the state of the material. We have examined irreversible shifts in the dominant autofluorescence spectra of proteins denatured by HIFU heating. These shifts appear to be related to protein conformational changes due to denaturation. We report on the feasibility of using optical autofluorescence as a means of quantifying in vitro lesion formation by HIFU for optically accessible tissues.
Light, sound, nanobubbles: New approach to contrast-enhanced ultrasound and photoacoustic imaging
Authors: Emelianov Stanislav
Published: April 2019

To overcome the most significant deficiencies of conventional and contrast-enhanced ultrasound imaging—low contrast and large size of microbubbles, we introduced new class of contrast agents—nanometer scale particles that are capable of escaping vascular compartments, penetrating into tissue, and then, once they reach the target site, generating sufficient ultrasound and photoacoustic contrast upon user-controlled optical activation. These multimodal contrast agents—phase-change perfluorocarbon nanodroplets and plasmonic nanoparticles covered by azide compounds—are stable at physiological temperatures, biocompatible, and monodisperse in size. Given the unique properties of the particles, our approach to image these particles is drastically different and is based on ultrasound read-out of the optically induced temporal changes. Specifically, time-varying ultrasound signals exhibited by the nanoparticles versus the static background are used to reconstruct a high contrast, background-free image of the contrast agent. Furthermore, these particles allow for multiplexed molecular imaging by permitting user-controlled triggering of distinct color-coded populations of contrast agents via tuning of the incident laser irradiation to match peak optical absorption of the particles. Finally, nanoparticles may also contain therapeutic cargo and thus can be used for controlled drug delivery and release. This presentation, via examples, will discuss diagnostic imaging and image-guided therapy using the gas-generating nanoparticles.
Small room auralizations: Investigating hybrid methods of acoustic simulations utilizing wave field synthesis
Authors: Scott E. K. Ellington , Braasch Jonas
Published: April 2019

Auralizations have become a beneficial tool in acoustic design of performance spaces, but nearly all research has been limited to Western classical music venues. Other venues, for example, jazz clubs, pose very different auralization challenges because their dimensions are typically smaller, and pure geometrical methods can no longer be applied. With a dramatic increase in computational performance, an effort has been placed in integrating geometric and wave-based models in auralization simulations that are suitable to auralize smaller venues. Finite difference time domain methods are applied for low-frequency numerical analysis of the Dizzy’s Club Coca-Cola and The Village Vanguard. This research endeavors to establish a method in identifying the crossover frequency between the geometric and wave-based models, as it pertains to small room acoustics to recreate the sound of jazz venues using the wave field synthesis. The 128-channel wave field synthesis system of Rensselaer’s Collaborative Research Augmented Immersive Virtual Environment Laboratory (CRAIVE-Lab) is used to perceptually evaluate the hybridized auralizations. Room acoustical measurements are obtained within the rendered sound field and compared to the measurements of the original locations for an objective analysis.
Spectral and temporal models of human pitch perception with mixtures of three concurrent harmonic complexes
Authors: Graves Jackson , Oxenham Andrew J.
Published: April 2019

In music and other everyday situations, humans are often presented with three or more simultaneous pitches, each carried by a harmonic complex tone, but few empirical or theoretical studies have addressed how pitch is perceived in this context. In three behavioral experiments, mixtures of three concurrent complexes were filtered into a single bandpass spectral region, and the relationship between the fundamental frequencies and spectral region was varied in order to manipulate the extent to which harmonics were resolved either before or after mixing. Listeners were asked to discriminate major from minor chords (Experiment 1) or to compare the pitch of a probe tone to that of a target embedded in the mixture (Experiments 2 and 3). In all three experiments, listeners performed above chance even under conditions where traditional rate-place models would not predict individually resolved components. Human behavioral results were compared to predictions from two classes of pitch model: a rate-place model using harmonic template matching and a temporal model using summary autocorrelation. Predictions from a combined model, using both rate-place and temporal information, were more accurate than predictions from either model alone, suggesting that humans may integrate these two kinds of information. [Work supported by NIH grant R01DC005216.]
Correlation-based temporal model of pitch multiplicity
Authors: Cariani Peter
Published: April 2019

Global temporal models for pitch analyze population-wide, all-order interspike interval distributions of the entire auditory nerve to accurately predict almost all known F0-pitch phenomena. Population-interval distributions (PIDs) are neural representations that resemble log-frequency scaled, half-wave rectified summary autocorrelation functions (SACF) of stimuli. PIDs produced by periodic stimuli show regular patterns of lag peaks associated with subharmonics of harmonics, with major peaks at n/F0, whereas early global temporal models chose the highest PID peak to estimate one, dominant pitch, later models compared average interval-densities of different sets of F0-related PID peaks to estimate relative pitch saliences, all saliences above a threshold being audible. However, this method inherently generates octave confusions amongst related subharmonics. Using Pearson correlation coefficients between PIDs and periodicity-related lag patterns (lags at n/F0) to estimate pitch saliences obviates the octave ambiguity problem and lag-weightings. The results from recent simulations using the Zilany-Bruce-Carney ANF model to estimate the pitches heard for dyads and triads of complex harmonic tones will be presented. For triadic chords (major, minor, suspended, augmented, and diminished), the model estimates relative saliences of F0s of notes, fundamental basses, and individual harmonics). Correlation salience values indicating relative pitch strengths (pitch stabilities) generally comport with music theoretic rankings for these chords.
Calibration of an ultrasonic transducer in a standing wave field
Authors: Kumar Krishna N. , Campbell Tyler , Saloio Jack , Chitale Kedar C. , Lipkens Bart
Published: April 2019

Acoustofluidics is one of the emerging technologies for cell sorting. Most of the acoustofluidics platforms use an acoustic standing wave field for the separation. The calibration of the standing wave field is a challenging task. In the past, there have been few studies to quantify the standing wave indirectly using particle tracing in the field. In the present work, we attempt to calibrate the standing wave field using acoustic techniques. Hydrophones are used to find the pressure in an acoustic field. They are designed and constructed in a way that they do not alter the field. Most of the commercial hydrophone in market is made of PVDF (polyvinylidene fluoride): an acoustically transparent material. When a hydrophone is inserted in a standing wave field, the field in front of the tip is no longer a standing wave field as PVDF is acoustically transparent. This was observed in our acoustic chamber also. Here, we propose to use the receiving characteristics of a transducer to quantify the standing wave field. In brief, two identical PZT transducers are used to generate the standing wave field: one as a transmitter and other as a receiver (reflector). The receiving characteristics of the transducer used as a reflector are calibrated using a needle hydrophone. Using the signal recorded by the receiving PZT transducer in the standing wave field and the calibration value, the pressure at the surface of reflecting transducer can be found. For the sake of comparison, the field will be quantified also by the particle tracing method.