bluuebunny/crossref_metadata_2025 huggingface dataset:
Manipulation of microbubbles and targeted single cell sonoporation with by surface acoustic waves in a microﬂuidic device
Authors: Meng Long , Cai Feiyan , Chen Juanjuan , Niu Lili , Zheng Hairong , Wu Junru
Published: November 2016

A microfluidic device was developed to transport the aggregated microbubbles to a targeted cell at arbitrary location in liquid solution by introducing the phase-shift to a planar standing surface acoustic wave (SAW). The device consists of two perpendicular pairs of interdigital transducer (IDTs) and a polydimethyl-siloxane microchannel. By adjusting the relative phase between electric voltages applied to the independent IDTs, the microbubbles can be trapped, continuously moved or rotated due to the translation of pressure nodes. We further demonstrate that a SAW is capable of inducing microbubble cluster destruction at a desired location to achieve a single cell’s reparable sonoporation. By controlling the position of the microbubble cluster relative to the targeted cell precisely, the effective size of the collapsing microbubbles is measured to be less than 0.68 times the diameter of microbubble cluster. The sonoporation efﬁciency and the cell viability are 82.4%± 6.5% and 90%±8.7%, respectively, when the targeted cell is within the effective microbubble destruction region.
An emulsification system using a microchannel and a piezoelectric transducer
Authors: Kanda Takefumi
Published: November 2016

Ultrasonic emulsification devices have been used in many industrial and scientific fields. Recently, a nanoemulsion which contains small droplets having a diameter of sub-micron scale have attracted attentions. In usual, those emulsions are produced by using ultrasonic transducers oscillated to generate a cavitation field. However, such process has a difficulty to avoid contaminations. For a continuous process, we have generated the nanoemulsion by using microchannel devices and a piezoelectric transducer. The devices are made of stainless steel mainly. The micron-size droplets generated by a Y-type or T-type microchannel device, and are oscillated by a piezoelectric transducer in another microchannel device. The driving frequency of the transducer is over 2.2 MHz. We have succeeded in generating sub-micron size droplets which contain anti-cancer drug using this emulsification system. Additionally, we have evaluated the acoustic field in the microchannel by using a micro cavitation sensor. The micro sensor made of a piezoelectric polymer has been installed in the device. The sensor consists of some films deposited and patterned with a photolithography process. Using this sensor, the acoustic state in the microchannel has been evaluated from the acoustic power spectrum. From the results, we can conclude that the cavitation effect is not dominant in the emulsification process by this system.
Hidden hearing loss and computational models of the auditory pathway: Predicting speech intelligibility decline
Authors: Smalt Christopher , Quatieri Thomas F. , Parker Mark A.
Published: November 2016

Recent animal studies have shown that noise exposures cause a permanent loss of low spontaneous rate auditory nerve fibers (ANFs) and reduction of auditory brainstem response wave-I amplitudes (Kujawa and Liberman, 2009). This phenomenon is thought to create difficulties understanding speech in noise in humans, although there is currently no established clinical technique to measure cochlear synaptopathy. The goal of this research is to utilize computational models of the auditory periphery and auditory cortex to study the effect of low spontaneous rate ANF loss on the cortical representation of speech intelligibility in noise. The auditory-periphery model of Zilany et al. (2009, 2014) is used to make predictions of auditory nerve responses to speech stimuli in noise. The resulting cochlear neurogram, a spectrogram-like output based on ANF outputs, is then used as a foundation for two different but related cortical representations of speech: the Spectro-Temporal Modulation Index (STMI; Elihali et al., 2003) and 2D Fourier Analysis (Wang and Quatieri., 2012). Reducing the number of low spontaneous rate ANFs in the cochlear neurogram was found to cause a blurring of speaker-specific cortical components, increasing the difficulty of speaker separation in the time-frequency modulation domain. Suprathreshold deficits in speech intelligibility, as simulated by auditory pathway models, may be predicting the effect of ANF loss or degradation on listening performance, and could potentially be used as part of a diagnostic tool.
Effects of hidden hearing loss on the representation of speech-in-noise in the gerbil auditory midbrain
Authors: McAlpine David , Undurraga Jaime , Garcia-Lazaro Jose , Schaette Roland
Published: November 2016

Increasing evidence indicates that noise exposure selectively damages high-threshold auditory nerve fibres, in the absence of damage to sensory hair cells. This “hidden hearing loss (HHL)"—undetected by conventional tests such as audiometry—is suggested to account for undiagnosed difficulties processing speech in background noise. Here, we demonstrate in the midbrain of gerbils exposed to a single, controlled noise insult, and in human listeners, evidence of increased neural gain in the central auditory pathways, indicative of damage to high-threshold ANFs following noise exposure. Neural responses were higher, and discrimination performance for 60-dB SPL “vowel-consonant-vowel” stimulus (VCVs in background noise (speech-shaped, + 12 to -12 dB signal-to-noise ratio) enhanced, in noise-exposed animals compared to controls. Conversely, for 75-dB SPL VCVs, neural discrimination was better in control, compared to noise-exposed, animals. A similar pattern was evident in human listeners, and was positively correlated with the ratio of wave V (generated by the midbrain) to wave I (generated by the auditory nerve) of the auditory brainstem response. The data are consistent with the hypothesis that reduced neural output from the cochlea at higher sound levels increases central gain through homeostatic mechanisms that seek to normalize neural activity.
Effects of aging on the absolute pitch judgment and frequency following responses of electroencephalograms
Authors: Tsuzaki Minoru , Tanaka Satomi , Sonoda Junko
Published: November 2016

Absolute pitch (AP) possessors can name the pitch class of the note simply by hearing a periodic tone. It has been reported that the AP judgment can shift by one or two semitones when AP possessor become old. We confirmed this age-related AP shift by a series of psychophysical experiments with piano sounds as well as synthesized complex tones. AP possessors whose ages ranged from 20s to 50s participated in the experiments. The results showed that the aged participants were likely to assign the higher pitch classes than young participants for the piano sounds. Similar tendencies were observed for the synthesized, complex sounds if they contained lower order harmonics. The hearing levels, OAEs, and the frequency following responses (FFRs) of the EEG were also measured for the same participants. The hearing levels and OAE levels which could be indices in the cochlear mechanical properties could not explain the age-related AP shift. The phase locking values of the FFRs obtained at 98 and 220 Hz could neither be a good predictor of the AP shift. Although no plausible model to predict it exists, the age-related AP shift might bring another route of overlooked hearing problems.
In-vivo intra-cellular characterization of “OFF” responses in the superior para-olivary nucleus
Authors: Franken Tom P. , Sayles Mark , Smith Philip H. , Joris Philip X.
Published: November 2016

The superior para-olivary nucleus (SPN) is an auditory-brainstem OFF channel. Typically, SPN neurons are inhibited during sound presentation and fire at sound offset. Release from sound-induced inhibitory potentials is the hypothesized mechanism, but this has not previously been directly observed in vivo. We obtained in vivo axonal recordings from 33 SPN neurons in the chinchilla, and patch recordings from 17 SPN cell bodies in the Mongolian gerbil. We retrieved several cells anatomically by labeling with biocytin or neurobiotin. Labeled SPN neurons had large dendritic trees, and axons heading into the lateral lemniscus. Their responses typically showed offset spiking to contralateral, and sometimes to ipsilateral stimulation. Spikes in response to amplitude-modulated tones were highly synchronized, up to hundreds of Hz (vector strength >0.9). Some SPN neurons were ITD sensitive, either to envelope or low-frequency fine-structure components. Patch-clamp recording allowed us to study sub-threshold potentials. Large IPSPs were generated by contralateral, and often also by ipsilateral sounds, with few EPSPs. Individual phase-locked IPSPs were discernable to low-frequency tones. High-frequency tones elicited a large onset IPSP, followed by sustained inhibition. For amplitude-modulated tones, IPSPs were locked to the stimulus envelope, with spikes at the offset of inhibitory events.
Against “broadening with sound level”
Authors: Sayles Mark , Fontaine Bertrand , Smith Philip H. , Joris Philip X.
Published: November 2016

Spectral resolution is fundamental to audition. Auditory-nerve-fiber responses provide a window onto cochlear tuning. Typically, resolution is quantified using threshold tuning curves. Superficially, these suggest dramatic and systematic filter broadening with increasing intensity, a view often invoked to explain psychoacoustic phenomena. We recorded auditory-nerve-fiber spike times from normal-hearing chinchillas in response to 0.01-20 kHz wideband noise. We gathered data over a wide intensity range from each fiber. Linear filter estimates were obtained at each level by reverse correlation. We characterized their magnitude and phase response. We considered responses from 175 fibers (CF range: [0.1, 3.0] kHz; all SR groups), with noise level varying over a 40 to 100-dB range. 10-dB bandwidth varied minimally with sound level over a 40 to 50-dB range. Some fibers demonstrated phase pivoting with level; however, most did not follow this simple scheme. Common teaching is “auditory filters broaden with level,” usually in reference to threshold tuning curves. Here, gain functions constructed from responses to a fixed-level input show this broadening is not as severe as threshold tuning curves might suggest. Broadening is very subtle over a large range of “low” to “mid” input intensities (<70-dB SPL), before rapidly increasing at “high” levels (>80-dB SPL).
Evolutionary elongation of the time window of auditory cortical processing: Comparison of effects of stimulus time parameters on human and macaque scalp auditory evoked potentials
Authors: Itoh Kosuke , Nejime Masafumi , Konoike Naho , Nakamura Katsuki , Nakada Tsutomu
Published: November 2016

Auditory cortex integrates sound signals over time for obtaining neural representations of auditory events, the time window of which affects perception and cognition. Species differences between human and macaque monkey in the time window of auditory cortical processing were investigated by comparing (1) how the cortical auditory evoked potentials (CAEP) increase in amplitude with the duration of a sound (2-200 ms), and (2) how the CAEPs to a repetitive stimulus train recover from neural adaptation with an increase in interstimulus silent interval (30-1620 ms). A virtually identical noninvasive scalp recording method was used in the two species for rigorous comparisons. First, the integration windows for the human N1 and N2 were 50 ms or longer, but the macaque N1 (mN1) and macaque N2 (mN2) were elicited with their full amplitudes by a stimulus as short as 2 ms. Second, the human N1 to a repeated stimulus continued to recover from neural adaptation as the interstimulus interval increased to 1620 ms, and a clear elicitation of N2 required an interval longer than 500 ms; in the macaque, by contrast, mN1 fully recovered from adaption by an interval shorter than 1 s, and a clear mN2 was elicited with a 30 ms gap. These findings are consistent an evolutionary elongation of the time window of human auditory cortical processing, which enables integrating greater amount of auditory information over time to obtain neural representation of complex auditory features that characterize language and music.
Interaural-time-difference discrimination as a measure of place of stimulation for cochlear-implant listeners with single-sided deafness
Authors: Stakhovskaya Olga , Schuchman Gerald I. , Goupell Matthew J. , Bernstein Joshua G.
Published: November 2016

Recently, some patients with single-sided deafness (SSD) have received a cochlear implant (CI), with the goal of improving their spatial-hearing abilities. Because electrode arrays typically do not reach the cochlear apex, standard frequency-to-electrode allocations are likely to create a substantial interaural cochlear place-of-stimulation mismatch, and might not optimize binaural function for SSD-CI listeners. As a first step, we evaluated whether a test of interaural-time-difference (ITD) discrimination could be used to identify the cochlear place of stimulation for individual electrodes. Six SSD-CI listeners were presented with 500-ms bursts of 100-pps electrical pulse trains on a single electrode, and bandlimited pulse trains with variable carrier frequencies in the acoustic ear. Listeners discriminated between two “static” intervals (each containing four bursts with constant ITD) and a “moving” interval (four bursts with variable ITD). For most listeners and electrodes, performance peaked at a particular acoustic carrier frequency, which was on average 0.57 octaves higher (range = -0.2-1.1 octaves) than the standard clinically allocated center frequency. These results demonstrate that an ITD-discrimination task can identify the optimal frequency allocation required for a given CI electrode to maximize binaural function for SSD-CI listeners. The opinions and assertions presented are the private views of the authors and are not to be construed as official or as necessarily reflecting the views of the Department of Defense.
Prototype of a low-cost towed array with data-logging and short-range telemetry
Authors: Romero-Vivas Eduardo , Von Borstel Fernando D. , Villa Medina Francisco , Bustamante Omar A. , Beristain Sergio , Gutiérrez-Jagüey Joaquin
Published: November 2016

Passive Acoustic Monitoring studies have been benefited from open source software initiatives such as PAMGuard and ISHMAEL, but their widespread use is often limited by availability of low cost hardware. This work presents the design of a towed hydrophone array that can be built with off the shelf components. The system comprises a Raspberry Pi computer to log GPS, three-axis accelerometer, magnetometer, gyroscope, and audio from the hydrophone array (20 Hz-44 kHz). Data can be analyzed in PAMGuard, either in real time, through a short range (10 m) RF link, or retrieved later from the data logger. The array has been tested in La Paz bay Mexico, where semi-resident populations of long-beaked common dolphin (Delphinus capensis) and bottlenose dolphin (Tursiops truncatus) have been reported. Results and performance of the array in four modalities are presented; as a drift array, as a secondary array deployed from a small vessel, as an array towed by a Kayak, and as an array towed by an Autonomous Surface Vehicle. This array provides a useful tool for fieldwork, and since it is built form off the shelf components on a low budget, it could also be used for educational purposes, such as in PAMGuard Courses.
Characterization of the lung parenchyma using ultrasound multiple scattering
Authors: Mohanty Kaustav , Blackwell John , Egan Thomas , Muller Marie
Published: November 2016

We use multiple scattering of ultrasound waves to characterize the lung micro-architecture in order to differentiate between a healthy lung and a lung suffering from Alveolar Interstitial Lung Diseases. The experimental setup consists of a linear transducer array with an 8 MHz central frequency placed in direct contact of the lung to be assessed. The diffusion constant D and scattering mean free path L* of the lung parenchyma are estimated by separating the incoherent and the coherent intensities in the near field. 2D FDTD numerical simulations were carried out on rabbit histology images with varying degrees of lung collapse. Phantom experiments were conducted in melamine sponges to study the variations in D and L* with varying air volume fraction. Significant correlations were observed between air volume fraction and L* in simulation (r = -0.9542, p<0.0117) and sponge phantom experiments (r = -0.9932, p<0.0068). Finally, in vivo measurements were conducted in healthy and edematous rat lungs. In the control rat lung, L* was found equal to 83 μm ( + /-14.9), whereas in the edematous lung, it was found equal to 260 μm ( + /-27). These results are extremely promising for the assessment of lung pathologies using ultrasound.
500-MHz scanning acoustic microscopy of cancerous human lymph nodes
Authors: Mamou Jonathan , Rohrbach Daniel , Saegusa-Beecorft Emi , Machi Junji
Published: November 2016

Scanning acoustic microscopy (SAM) at 500 MHz permits forming 2D maps of the speed of sound (SOS), attenuation (A) and acoustic impedance (Z) of tissue microstructure with a spatial resolution of 4 μm. Maps from cancerous lymph nodes (LNs) can improve understanding of ultrasound scattering at 25 MHz and thereby can improve the specificity and sensitivity of quantitative ultrasound (QUS) methods for clinically significant micrometastases. SAM data were acquired from ten fixed LNs from colorectal-cancer patients. Deparaffinized, 6-μm thick sections were scanned using a custom-built SAM equipped with a 500-MHz transducer having a 264-MHz bandwidth and a 4-μm lateral beamwidth. Reflected signals were digitized at 2.5 GHz and maps of Z, A, and SOS were generated. Histological thin sections adjacent to the scanned samples were stained using hematoxylin and eosin, and metastatic regions were demarcated on the photomicrograph. The 4-μm spatial resolution permitted distinguishing metastases from other tissue types. The average Z for metastases was 1.66 ± 0.06 Mrayl, which was significantly larger than the average Z of surrounding tissue. Spatial variations in the Z maps will translate into new ultrasound-scattering form factors, which are expected to improve QUS approaches for detecting metastases in LNs. [NIH Grant R21EB016117.]
Modeling wave propagation through the skull for ultrasonic transcranial Doppler
Authors: Gupta Shreyank , Haïat Guillaume , Laporte Catherine , Bélanger Pierre
Published: November 2016

One problem associated with transcranial Doppler ultrasound (TCD) is the relatively low energy penetrating inside the brain through the skull, seriously limiting the image quality. This may be due to the impedance mismatch at the bone interface and to the bone frequency dependent attenuation. The objective of this paper is to model ultrasonic wave propagation through the skull. To do so, an analytical model was developed based on the estimation of the transmission coefficients inside the brain, leading to frequency dependent overall transmission coefficient for a given skin and bone thickness. Moreover, a finite element model was developed taking into account absorption phenomena. Both methods were validated experimentally by comparing the numerical and analytical results with results obtained from a phantom mimicking the skull having an attenuation coefficient equal to 30 dB/cm at 2.25 MHz and a thickness of 4.4 mm. A 2 mm layer of water mimicked the skin. The difference between the maximum amplitude of normalized received US signals obtained analytically and experimentally was 1%. The average relative difference between them was 0.3%. Thus, a working model is designed which can predict the energy inside the brain. Furthermore, the results show that impedance mismatch plays a major role in transmission loss rather than frequency dependent attenuation
Comparison between an axial transmission device and high resolution peripheral quantitative computed tomography—A clinical evaluation of ultrasound for the assessment of cortical bone quality
Authors: Suetoshi Ryoichi , Cretin Dorian , Chiba Ko , Osaki Makoto
Published: November 2016

Quantitative ultrasound mainly evaluates cancellous bones, although cortical bone is now thought to be more important to determine bone fragility. Therefore, we developed an axial transmission device (f = 3MHz) to measure the cortical Speed of Sound (cSOS). The purpose of this study is to investigate the material properties in cortical bone that cSOS reflects by using High Resolution-peripheral Quantitative CT (HR-pQCT). In 19 patients and healthy volunteers (aged 33-73), the cSOS at the tibia and radius were measured by our ultrasonic device. Cortical bone parameters were measured by HR-pQCT (Scanco). Areal bone mineral density (aBMD) at the lumbar spine and femur were measured by DXA. cSOS had a strong correlation with the cortical volumetric mineral density (Ct.vBMD) measured by HR-pQCT at both the tibia and the radius (r = 0.83, 0.72, p<0.001). A correlation was also found between cSOS and the cortical porosity at the radius (r = -0.83, p<0.001). No correlation was found between cSOS and aBMD, which makes cSOS unlikely to depend on the bone quantity. The correlation between cSOS and Ct. vBMD may show that cSOS could reflect the bone quality related to mineralization and porosity. cSOS, not being related to DXA but linked to the bone quality, could be useful for the screening of the mineral properties of cortical bone simply and non-invasively.
Induced electric potential in cortical bone and cartilage by ultrasound irradiation
Authors: Mori Shunki , Matsukawa Sayaka , Kawase Mami , Takayanagi Shinji , Matsukawa Mami
Published: November 2016

LIPUS (low intensity pulse ultrasound) can reduce the time of bone fracture healing. The detailed mechanism of ultrasonic effects on bone, however, has not been clearly understood yet. One possible idea seems to be the piezoelectricity of bone. The purpose of this study is to evaluate the piezoelectricity of cortical bone and cartilage. In order to evaluate piezoelectricity of bone in the MHz range, bone transducers were fabricated. Circular plate cortical bone samples and cartilage samples (diameter; 10.0 mm, thickness; 1.00 mm) were used as piezoelectric materials of the transducer to receive ultrasound. The surface of bone plates was normal to the bone axis or the radial axis and that of cartilage plates was normal to bone axis. By irradiating ultrasound in the MHz range, induced electric potentials were successfully observed in all transducers. The maximum sensitivity of the cartilage transducer was about 93.6 nV/Pa and that of the bone transducer was about 27.5 nV/Pa. Induced electric potentials of cartilage transducers were always larger than those of bone transducers. The main part of the cartilage is type collagen. The results may indicate that the piezoelectricity of the cartilage and bone mainly comes from the collagen.
Ultrasound for bone tissue engineering and regenerative medicine
Authors: Padilla Frederic , Fabiilli Mario L. , Martín-Saavedra Francisco M. , Raum Kay , Puts Regina , Vico Laurence , Wilson Christopher G.
Published: November 2016

We will review the role of ultrasound in bone tissue engineering and regenerative medicine, for enhancement of fracture healing and reactivation of a failed healing process. These approaches rely typically either on the direct stimulation of the healing process or in the delivery at the injury site of scaffold-embedded biologics such as cells, signaling molecules, and genetic material. Different options are available for ultrasound enhancement of fracture healing such as low intensity pulsed ultrasound (LIPUS) and shock waves, for the delivery of regenerative factors and encoding genes, and for the assembly and patterning of scaffolds. A main emphasis will be put on LIPUS-related bioeffects, the most widespread and studied technique. Pronounced bioeffects on tissue regeneration have been reported employing intensities within a diagnostic range. We will describe the current knowledge of the biological response to LIPUS, involving numerous cell types and molecular pathways, hypothesis about LIPUS biophysics, and our recent findings on mechanosensitive transcriptional response of cells after LIPUS. We will also present the use of focused ultrasound to spatiotemporally control the delivery of growth factors, either by induction of transgene expression controlled by a heat-activated and ligand-dependent gene-switch, or by triggered release using acoustic droplets vaporization within biopolymer scaffolds.
Activities of the research committee on education in acoustics in ASJ for children
Authors: Satoh Fumiaki , Arai Takayuki , Nishimura Akira
Published: November 2016

In the Acoustical Society of Japan (ASJ), the Research Committee on Education in Acoustics was established in 1997. Although its history is relatively short in comparison with the Administrative Committee on Education in Acoustics in the Acoustical Society of America (ASA), many activities have been steadily carried out. For example, surveys of syllabi (educational plans of subjects in universities) were made. Demonstration tools used in university classes were also surveyed. The extent of our research was not limited to only universities. Textbooks and teaching materials used in elementary schools, junior high schools, and senior high schools were also researched. Furthermore, activities in cooperation with the National Museum of Nature and Science in Japan have been taking place, including an exhibition and a class with acoustic demonstrations and handicrafts for children. We believe that such activities are very important as social contributions of an academic society. In this presentation, some of our activities focusing on the education for children will be introduced.
Assessment of the Acoustical Society of America educational activity kit: Survey results from K-12 teachers
Authors: Vigeant Michelle C. , Morrison Andrew C.
Published: November 2016

The Committee on Education in Acoustics within the Acoustical Society of America developed an activity kit for K-12 teachers to use in the instruction of the fundamentals of sound in 2011. The kit includes activities that cover a range of topics, including musical instruments, animal bioacoustics, and hearing loss. Supplies for many of the activities are provided, including tuning forks, a sound level meter, and materials to make instruments. Many electronic resources are also available online, including lesson plans. Since 2011, over 475 kits have been distributed to K-12 teachers across the United States. To evaluate the effectiveness of the kits, a survey was sent out to all kit recipients. The response rate was 23% (n = 102), with 58% of the respondents being high school teachers. Out of the eight primary activities, the two activities with the highest ratings were (1) striking and listening to the tuning forks, which demonstrates the concepts of frequency and wavelength, and (2) touching a ping pong ball suspended on a string, to a tuning fork, which demonstrates the concepts that sound is a form of vibrational energy and amplitude. The presentation will highlight the key results from the survey and include a sample of the comments.
Bacterial attachment and insertion loss of earplugs used for fixed periods in noisy workplaces
Authors: Inoue Jinro , Nakagawa Yumi , Nakamura Aya , Kawanami Shoko
Published: November 2016

In noisy workplaces, employees often tend to use earplugs for a long time in Japan. We have previously reported conditions related to bacterial attachment and the insertion loss of earplugs using data collected from six companies. In the present study, we distributed different kinds of foam earplugs at five companies and collected them after 1-, 2-, 4-, and 8-week usage (n = 123). We examined the total viable counts and presence of Staphylococcus aureus using 3M Petrifilm. We evaluated the insertion losses by means of the GRAS 45CB Acoustic Test Fixture. We detected a large number of viable counts in 5% of the earplugs. We found Staphylococcus aureus in 7% of the earplugs. We observed a small deterioration in insertion loss after 8-week usage. Neither the condition of bacterial attachment nor the insertion loss correlated with duration of use. We discuss the proper usage of earplugs in terms of industrial health.
Communication and situation awareness needs of hearing protection systems in high noise environments
Authors: Yankaskas Kurt
Published: November 2016

The primary mission of aircraft carriers is to launch and recover military aircraft. Critical to the highly choreographed operations on the flight deck of the aircraft carrier is communications between aircraft directors, plane crews, and pilots as well as maintaining situation awareness in a highly dynamic environment. This must occur in an acoustic environment of 110 to 150 + dBA. These noise levels readily exceed the requirements for double hearing protection. A dilemma is generated in trying to provide adequate hearing protection while maintaining critical communications and situation awareness during flight operations at these noise levels. This paper will review previous studies of hearing protection effectiveness, compliance, factors affecting compliance, and impact on job performance in environments that readily exceed legacy hearing protection. To address the situation awareness shortfalls, a tri-service group (US Army, Air Force and Navy) is developing a standard for detection and localization criteria (commonly known as situation awareness) to assess operational suitability. The standard is intended to drive manufacturers to measure beyond the attenuation a hearing protector provides to address operational needs. New products and techniques are presented which demonstrate a potential solution sets to this critical issue.
Assessing the performance capabilities of tactical hearing protection and communication devices
Authors: Gallagher Hilary , Thompson Eric R. , McKinley Richard L.
Published: November 2016

Military personnel work in unpredictable noise environments, which require flexible types of hearing protection (i.e., tactical hearing protection systems) in order to maintain mission effectiveness and situation awareness while reducing the risk of hearing loss. Acquisition decisions need to be made relative to accurate and complete measures of the total performance capabilities of tactical hearing protection systems and their effect on the user. Understanding the noise attenuation performance of tactical hearing protection systems has been a priority in order to protect the user from excessive noise exposure. However, active electronic tactical hearing protection systems have been designed to allow for enhanced communication and situation awareness, while at the same time protecting the auditory system from both impulsive and continuous noise. The Air Force Research Laboratory conducted a multifactorial assessment on currently available tactical hearing protection systems to determine the overall impact of these devices on performance and to enable users to make data-driven, informed acquisition decisions. The assessments included the following measurements: continuous noise attenuation, impulsive peak insertion loss, auditory localization, and speech intelligibility. The methods and results will be presented as well as a discussion on how the results promote an informed device selection.
Sound localization performance with level-dependent hearing protection devices
Authors: Thompson Eric R. , Romigh Griffin D.
Published: November 2016

Level-dependent hearing protection devices (HPDs) offer the promise of the ability to hear low-level sounds while providing protection against dangerous high-level sounds. These devices are useful for people who may be exposed to intermittent, unexpected loud sounds while operating in environments that are otherwise generally quiet. Often, it is important for these users to be able to localize sounds and to maintain auditory situation awareness in these environments while wearing the HPDs. Measurements were made of listeners’ abilities to localize quiet and loud sound sources while wearing different level-dependent devices, as well as with unprotected ears. Electroacoustic measurements were also made with the devices on an acoustic test fixture to characterize their input-output functions, effective bandwidths, and directional transfer functions. Sound localization performance was typically worse when wearing the HPDs than with unprotected ears, with more front/back confusions, especially for the devices that have the least variance in their directional transfer functions. Auditory models were used to predict the human localization performance with the electroacoustic measurements as inputs.
Parity-time synthetic phononic media
Authors: Christensen Johan
Published: November 2016

Classical systems containing cleverly devised combinations of loss and gain elements constitute extremely rich building units that can mimic non-Hermitian properties, which conventionally are attainable in quantum mechanics only. Parity-time (PT) symmetric media, also referred to as synthetic media, have been devised in many optical systems with the ground breaking potential to create nonreciprocal structures and one-way cloaks of invisibility. Here we demonstrate a feasible approach for the case of sound where the most important ingredients within synthetic materials, loss and gain, are achieved through electrically biased piezoelectric semiconductors. We study first how wave attenuation and amplification can be tuned, and when combined, can give rise to a phononic PT synthetic media with unidirectional suppressed reflectance, a feature directly applicable to evading sonar detection. Nature Rev. Mater. 1, 16001 (2016); Phys. Rev. Lett. 116, 207601 (2016); EPL, 114, 4, 47007 (2016).
Structure and Magnetism of EuTiO3
Authors: Keppens Veerle M.
Published: November 2016

The tilting of the oxygen octahedra in cubic perovskites is known to induce structural phase transitions, which are often associated with the emergence of intriguing physical phenomena. While SrTiO3 is one of the most extensively studied perovskite oxides for its structural phase transition at 105 K, the discovery of magnetoelectric coupling in isostructural EuTiO3 has triggered many theoretical and experimental studies focused on this compound. I will present resonant ultrasound studies of the extremely subtle cubic to tetragonal structural phase transition at 288 K in EuTiO3 single crystals and the evolution of the physical properties upon chemical doping. The collective set of experimental data contributes to a better understanding of the link between lattice, magnetic, and electrical degrees of freedom in the EuTiO3 system, helps evaluate the similarities and differences between SrTiO3 and EuTiO3, and provides insight in the possible origin of the much higher structural transition temperature for EuTiO3 compared to SrTiO3.
Discussion on very small temperature dependence of diamond’s elastic constants
Authors: Nagakubo Akira , Ogi Hirotsugu , Hirao Masahiko
Published: November 2016

Diamond shows high Debye temperature (~2200 K) and small Gruneisen parameter (~1), which represent its small anharmonicity. Therefore, the temperature dependence of elastic constants is very small, preventing accurate measurement. Recently, we measured the temperature dependence of C11 of diamond by using picosecond ultrasonics. [A. Nagakubo et al., Appl. Phys. Lett. 108, 221902 (2016).]. Our results indicate that diamond has a further higher Debye temperature than previous measurements, and we found that elastic constants of high-Debye-temperature materials should be measured over a wide temperature range to extract the Debye temperature and the Gruneisen parameter, accurately. We also calculate the temperature dependence of C11 by an ab-initio method, which agree with our measurement. In this study, we discuss the temperature dependence of other elastic constants. We found that careful consideration is required for bond-bending and bond-stretching resistance to evaluate the temperature dependence of its elastic constants.
Effect of stress wave irradiation on structural change in a colloidal system
Authors: Nakamura Nobutomo , Okuno Tasuku , Ogi Hirotsugu , Hirao Masahiko
Published: November 2016

Annealing is a typical method for controlling crystallographic structure of solids, and by increasing the number of phonon modes by heating, structural changes are caused. Considering that stress waves also enhance lattice vibrations, stress-wave irradiation should have similar effect on structural changes. In this study, we investigate the effect of stress-wave irradiation on crystallization of an amorphous solid using a colloidal system. A colloidal system used in this study is a mixture of a solution dyed with a fluorescein sodium salt and silica particles. It shows phases similar to those of atomic systems, and ordered (crystalline) and disordered (amorphous) structures are obtained. Because particle-scale analysis can be performed by using the confocal laser scanning microscopy, it has been used as a model system of atomic materials. We evaluate structural change of a colloidal glass after stress-wave irradiation and find that crystallization is accelerated at a specific condition. In the presentation, details of the results are described, and its origin is discussed.
Actuation and manipulation of nano-confined fluids and particles via room-temperature lithium niobate bonding
Authors: Miansari Morteza , Friend James
Published: November 2016

Controlled nanoscale manipulation of fluids and colloids is made exceptionally difficult by the dominance of surface and viscous forces. Acoustic waves have recently been found to overcome similar problems in microfluidics, but their ability to do so at the nanoscale remains curiously unexplored. Here, we show that 20 MHz surface acoustic waves (SAW) can manipulate fluids, fluid droplets, and particles, and drive irregular and chaotic fluid flow within fully transparent, high-aspect ratio 50-250-nm tall nanoslits fabricated via a new direct, room temperature bonding method for lithium niobate (LN). Applied in the same direction, SAW increases the capillary filling rate of the hydrophilic LN nanoslit by 2–5 times. Applied in opposition, the SAW switches the flow direction and drains the channel against 1 MPa capillary pressure, and can be used to controllably manipulate ~10 fL droplets. Finally, entire 10 μL droplets can be sieved via SAW through the nanoslit to pass only particles smaller than its height, providing pumpless size exclusion separation.
c-axis tilted ScAlN shear wave acoustic Bragg reflect resonator for gigahertz viscosity measurement
Authors: Mori Takeshi , Yamakawa Yui , Karasawa Rei , Sano Ko-hei , Takayanagi Shinji , Yanagitani Takahiko
Published: November 2016

c-axis tilted ScAlN film is attractive for resonators exciting shear wave ultrasonic. Shear mode resonators are suitable for biomarker sensing and viscosity sensing because shear mode resonators can operate without energy leakage to liquid. These sensors are well known as a QCM (Quartz Crystal Microbalance) consisting of AT-cut quartz crystal which excites shear wave ultrasonic. When the resonator is immersed in liquid, resonant frequency decreases due to the viscosity perturbation layer between the resonator and liquid interface. The rate of resonant frequency decrease depend on the mass ratio of viscosity perturbation layer and the resonator layer. Therefore, thinner high frequency resonator allows high sensitivity viscosity measurement. The maximum resonant frequency of the standard QCM plate is about 30 MHz. On the other hand, c-axis tilted ScAlN film can operates over 1 GHz. The sensitivity of the piezoelectric film sensors are much higher thanthat of the QCM sensors. In this study, we deposited shear wave c-axis tilted ScAlN film on the acoustic Bragg reflector. We clearly observed the shear wave excitation at the 990 MHz by using a network analyzer in air. Apparent resonant frequency shift of -16 MHz and -28.5 MHz was observed, when the sensor was immersed in the ethanol and pure water, respectively.
Micro and nanofluidics of the cochlea: Trade-offs of sensitivity and noise in an active biological system
Authors: Sasmal Aritra , Grosh Karl
Published: November 2016

The cochlea performs an analog time-frequency analysis on the incoming acoustic signal via a coupled electro-mechanical-fluidic response. The ultimate mechanical event that triggers the opening of the sensory mechanically gated ion channels is the fluidic shearing of the stereocilia of the inner hair cells (IHC) of the cochlea. Each IHC is equipped with a tuft of free standing stereocilia which are bathed in a 2-6 micron viscous fluid gap between the reticular lamina and the viscoelastic tectorial membrane. We use thin-film lubrication theory and asymptotics to model and solve a coupled viscous fluid-structure interaction problem to predict HB sensitivity to disturbance. The noise at the HB is due to the dissipation by the viscous forces (as quantified by the fluctuation-dissipation theorem) and stochastic fluctuations in the channel. We used this analysis study the challenges faced by evolution to sense the range of acoustic frequencies important to mammals. Structural acoustic calculations show that the parameters that increase noise may also increase the sensitivity of the system. In this study, the parametric trade-offs between noise and sensitivity of the system has been elucidated.
Perceptual interactions between adjacent time intervals marked by sound bursts
Authors: Nakajima Yoshitaka
Published: November 2016

Perceptual interactions take place between adjacent time intervals up to ~600 ms even in simple contexts. Let us suppose that two adjacent time intervals, T1 and T2 in this order, are marked by sound bursts. Their durations are perceptually assimilated in a bilateral manner if the difference between them is up to ~50 ms. When T1 ≲ 200 ms and T1 ≲ T2 < T1 + 100 ms, T2 is underestimated systematically, and the underestimation is roughly a function of T2—T1. Except when T1 ≃ T2, this is assimilation of T2 to T1, partially in a unilateral manner. This systematic underestimation, time-shrinking, disappears when T1 > 300 ms. When T2 = 100 or 200 ms and T1 = T2 + 100 or T2 + 200 ms, T1 is perceptually contrasted against T2: T1 is overestimated. When 80 ≤ T1 ≤ 280 ms and T2 ≥ T1 + 300 ms, T2 is contrasted against T1: In this case, T2 is overestimated. Assimilation and contrast are more conspicuous in T2 than in T1. For three adjacent time intervals, T1, T2, and T3, the perception of T3 can be affected by both T1 and T2, and the perception of T2 by T1.
Varieties of attention affect auditory perception of scenes
Authors: Snyder Joel S. , Yerkes Breanne , Irsik Vanessa , Vanden Bosch der Nederlanden Christina
Published: November 2016

Past empirical work on perception of complex auditory scenes has demonstrated striking effects of attention on perception. Here, we present data from recent studies of auditory stream segregation and change deafness, demonstrating that different types of attention influence what is perceived. During auditory stream segregation, we found that the increasing tendency to perceive segregation as more alternations of low and high tones are presented (i.e., buildup) is facilitated by attending to the tone patterns, regardless of whether participants were actively making judgments of segregation. In contrast, performing the segregation task was necessary to enhance the influence of the frequency separation of the immediately prior tone pattern, suggesting a form of task-based (as opposed to stimulus-based) attention. During change detection, we found that cueing participants to which object is likely to be replaced in a scene of multiple objects facilitates successful detection of changes, while providing an invalid cue impairs detection. Furthermore, an object-encoding task performed after each change detection response suggests that attending to objects specifically involved in the change facilitates awareness of changes. These two lines of research together suggest the need to systematically investigate under what conditions various types of attention influence auditory perception.
Listening in crowded environments: How attention shapes brain responses to unattended sounds
Authors: Bates Daniel , Molloy Katharine , Lavie Nilli , Chait Maria
Published: November 2016

I will review recent work in my lab concerning the effect of attentional focus on brain responses to unattended sounds. The first series of experiments aimed to understand how the neural representations of tracked (attended) and ignored sources change with growing scene size. We used acoustic “scenes,” comprised of multiple concurrent tone-pip streams, and a task which required listeners to track one of the streams over a long duration (30 seconds). EEG results show that attention boosts/reduces responses to the tracked/ignored sources, manifested as enhanced/reduced spectral power at its AM rate. The strength of this effect is dependent on the number of competing sources. We also demonstrate increased power coupling between activity in the alpha band and the brain responses to ignored sounds, implicating alpha in the process of active suppression of task-irrelevant information. In the second series of experiments (Molloy et al., 2015), we investigate the effect of focused visual attention on responses to simple sounds (pure tones). High, compared to low, perceptual load led to reduced early (~100ms) auditory-evoked activity and later suppression of the P3 “awareness” response. These findings support an account of shared audio-visual resources, which, when depleted under load, result in failure of perception. Reference: K. Molloy, T. D. Griffiths, M. Chait, N. Lavie (2015) “Inattentional deafness—an MEG study,” J Neurosci.35, 16046-54.
Detecting auditory changes by pupillary response
Authors: Liao Hsin-I , Yoneya Makoto , Kidani Shunsuke , Barascud Nicolas , Zhao Sijia , Chait Maria , Kashino Makio , Furukawa Shigeto
Published: November 2016

Detecting changes is an essential function that helps the organism to constantly monitor and update the information from the environment. In this talk, I will review our recent work, demonstrating that the human pupillary response can be used as a physiological marker for certain aspects of auditory change detection, in both simple and complex acoustic streams. In study 1, using simple repetitive tones with occasionally presented deviants (oddballs), we found that the oddball induces a pupillary dilation response (PDR), that is modulated by the stimulus properties irrespective of whether attention is directed to the sounds (Liao et al. 2016). In study 2, we examined whether PDR also reflects changes in complex acoustic patterns. We adopted the stimuli in Barascud et al. (2016) which contain transitions between random and regular tone-pip patterns. Results revealed an asymmetry: the PDR was observed only to changes from a regular to a random pattern, but not vice-versa. Overall, the results suggest that the PDR is not simply evoked by any kind of perceptual change per se. Rather, the pattern of results is consistent with the PDR reflecting changes that violate expectation. Possible underlying mechanisms and future directions are discussed.