bluuebunny/crossref_metadata_2025 huggingface dataset:
3D printed membrane-type acoustic metamaterials with structured masses
Authors: Leblanc Alexandre , Lavie Antoine
Published: November 2016

As society evolves, new technologies emerge. They should be considered to address persistent problems such as sound absorption at low frequencies. 3D solid prototyping printers are already used to obtain efficient sound diffusers, but remain marginal for creating acoustic absorbers. Recently, sub-wavelength absorbers have been proposed, particularly in the form of membrane-type acoustic metamaterials. These lasts usually consist on a decorated membrane resonator with tunable weight. In this work, membrane-type metamaterials are fabricated by fused deposition modeling, and both the membrane and the added masses are all made by the same flexible material. This allows to study other geometries, while structuring the added masses. Indeed, they can be split to increase peak efficiencies of this metamaterial to obtain an efficient band-stop filter. This application is illustrated with a base decorated membrane, using a divided central platelet and/or an additional split ring. Also, preliminary numerical simulations show that these structured membranes are likely to be more efficient than membranes with rigid inclusions when subjected to a diffuse sound field.
Elastic wave dispersion in pre-strained negative stiffness honeycombs
Authors: Goldsberry Benjamin M. , Haberman Michael R.
Published: November 2016

A doubly periodic array of curved beams, known as a negative stiffness (NS) honeycomb, has recently been shown to exhibit tunable impact isolation by exploiting nonlinear mechanical behavior [Correa et al., Rapid Prototyping J., 21 (2), 2015]. The primary benefit of NS honeycombs over standard honeycomb materials lies in their ability to return to their original shape after experiencing an impact. The recoverable nature of their response is a result of the curved beam structure which has a single stable configuration but experiences one or more buckling events when loaded. The complex nonlinear elastic response of NS honeycombs lead to large variations in mechanical stiffness, which makes these materials compelling candidates for tunable control of elastic waves. The present work investigates linear elastic wave propagation of a representative NS honeycomb lattice at varying levels of pre-strain. Eigenfrequency finite element analysis is performed on the unit cell subjected to finite uniaxial deformation. The longitudinal and transverse phase speeds are shown to be anisotropic and highly dependent on uniaxial pre-strain. This is especially true near points of instability, where one observes very different functional dependence of longitudinal and transverse wave motion on pre-strain.
Intonation contours in Hawai‘i Creole and Hawai‘i English show influence from Hawaiian
Authors: Anderson Victoria B. , Kirtley M. J.
Published: November 2016

Hawai‘i Creole (ISO 639-3 hwc) and Hawai‘i English (HE) are speech varieties spoken by local residents of the Hawaiian Islands. Three native speakers of HWC, seven native speakers of HE, and three native speakers of Hawaiian (ISO 639-3 haw) were recorded speaking in casual interviews, participating in map tasks, and saying phonetically controlled sentences. Analysis focused on utterances containing the high (or rise) plus steep fall contour, which is not found in Mainstream American English but is often used for continuations and polar questions in HWC, HE, and Hawaiian (Vanderslice & Pierson 1967, Anderson 2003, Murphy 2013). Results for all three speech varieties showed alignment of F0 minimums with lexically stressed syllables at the end of an intonation phrase, with F0 peaks occurring on immediately preceding syllables. All three speech varieties show a preponderance of this steep drop in continuations and polar questions, confirming the idea that this is a feature borrowed from Hawaiian (Bickerton and Wilson 1987, Anderson 2003.)
A preliminary ultrasound examination of Upper Sorbian rhotics
Authors: Howson Phil
Published: November 2016

Upper Sorbian has been influenced tremendously by German, causing it to adopting the uvular rhotic. The current study examines the uvular rhotic and its palatalized counterpart in three vocalic environments (word initial, intervocalic, and word final) with the vowels /a, e, o, i/ using ultrasound. The preliminary results indicate a striking difference between the two phonemes. The plain uvular rhotic was characterized by a retracted and raised tongue dorsum, accompanied by a slightly retroflexed tongue tip. The retroflexed tongue tip is surprising for a uvular rhotic. It could be related to requirements for rhotic production or a remnant of the alveolar rhotic Upper Sorbian had historically. The environments with /i/ were especially striking: the uvular rhotic was palatalized intervocalically; the tongue body was raised near the palatal region, while the dorsum retracted strongly. In other word positions, the rhotic caused a lowering and retraction of /i/. The palatalized rhotic had a raised tongue body, but the tongue dorsum was as retracted as the plain rhotic and less susceptible to environmental influence. The tongue tip was laminal in articulation, rather than retroflexed. The more consistently retracted tongue dorsum may be related to a need to maintain rhotic qualities. [Work supported by SSHRC.]
Duration of Japanese singleton and geminate stops with devoiced vowel in various speaking rates
Authors: Amano Shigeaki , Yamakawa Kimiko , Kondo Mariko
Published: November 2016

Previous studies have shown that a devoiced vowel makes burst duration of a singleton stop consonant longer than a voiced vowel does. However, the effects of devoiced vowels on stop consonants including a geminate have not been fully investigated. To clarify the effects, durations of a burst and a closure in Japanese stops pronounced by 19 native Japanese speakers were analyzed by stop type (singleton or geminate) and speaking rate (fast, normal, or slow). Analysis revealed that at all speaking rates a devoiced vowel makes the burst duration of singleton and geminate stops longer than a voiced vowel does. Analysis also revealed that at normal and fast speaking rates a devoiced vowel has no effect on closure duration in singleton or geminate stops. However, at a slow speaking rate, a devoiced vowel makes the closure duration of a singleton stop longer. These results indicate that a devoiced vowel consistently lengthens the burst duration of singleton and geminate stops but that its effects on closure duration depend on both stop type and speaking rate. [This study was supported by a special-research grant of Aichi Shukutoku University in 2015-2016, and by JSPS KAKENHI Grants Number JP 25284080 and 26370464.]
Ultrasound evidence for place of articulation and assimilation behaviors of the Japanese moraic nasal /N/
Authors: Mizoguchi Ai , Roon Kevin , Whalen D. H.
Published: November 2016

The syllable-final Japanese moraic nasal /N/ is commonly transcribed as velar or uvular or even placeless, but very little articulatory has been reported. This study investigated the tongue shape and position for /N/ in various phonological environments using ultrasound. /N/ assimilates to the place of following segments, so a variety of environments was also examined to assess whether the assimilation occurs categorically or gradually. Tens repetitions of 7 target words with a moraic nasal (/aNCa/, /aNa/, /aNaN/, and /ƜN/) and 6 control words without a moraic nasal (/aCa/, /aa/) were spoken by 4 native speakers of Japanese. Although there seems to be an oral target for moraic nasal, the place was different for each of our four speakers. The assimilation also varied among speakers, but a gesture for the moraic nasal remained in at least one phonological environment for all the speakers. Assimilation of Japanese moraic nasal to following segments is not always categorical and a gesture for the target of moraic nasal, even though varying among individuals, remains depending on the phonological environments. The ambiguities in transcribing /N/ seem to be reflecting the state of the language accurately: Even with four speakers, four patterns emerged. [Work supported by NIH DC-002717.]
Word boundaries attenuate the effects of emphasis in Lebanese Arabic
Authors: Pick Andrew N.
Published: November 2016

Arabic has a series of pharyngealized consonants, called “emphatics,” which are phonologically distinct from their plain counterparts. The strongest acoustic correlate of emphasis is a lowering of the second formant on vowels adjacent to the emphatic consonant. Arabic varieties differ in how far emphasis spreads, and previous work suggests that varieties may differ in whether emphasis can cross word boundaries. This study examines the effect of Lebanese Arabic emphatics on preceding vowels in two environments: within the word and within the phrase. Five native Lebanese speakers were recorded reading a list of phrases containing a target vowel preceding either an emphatic or plain consonant, with or without an intervening word boundary. In both environments, vowels preceding emphatic consonants have a lower F2 than vowels preceding plain consonants. Additionally, F2 is lowered more on vowels that are within the same word as the conditioning emphatic. Overall, these results indicate that emphasis in Lebanese Arabic affects preceding vowels within the domain of the word as well as the domain of the phrase, but this effect is stronger within the word.
The Pohnpeian stop contrast between laminal alveolars and apical dentals involves differences in VOT and F2 locus equation intercepts
Authors: Rentz Bradley , Anderson Victoria
Published: November 2016

Pohnpeian (ISO639-3 pon) is a phonetically understudied Oceanic language spoken by about 34,000 people in the Federated States of Micronesia, and 12,000 in the United States. Pohnpeian has a typologically uncommon laminal alveolar stop /t̻/ that contrasts with an apical dental stop /t̪/. Three male and two female native speakers were recorded in Honolulu, saying phonetically controlled wordlists in sentence frames. VOTs, F2s at vowel onset and steady state, and burst spectral moments (center of gravity and skewness) were measured in PRAAT and analyzed in R. Hierarchical linear modeling showed that /t̻/ has a significantly longer VOT than /t̪/. Linear regressions showed similar F2 locus equation slopes, but a higher intercept for /t̻/. Neither COG nor skewness exhibited significant differences. The locus equation intercept results, while similar to those of Sussman et al. 1993 for Urdu, have a different cause. Urdu /ɖ/’s higher intercept is due to higher F2 onsets than that of /d̪/, Pohnpeian’s /t̻/ and /t̪/ have similar F2 onsets; /t̻/’s higher intercept is due to vowel allophony: a lower F2 steady state for /t̻/. The burst spectral results remain puzzling in light of source-filter theory, which predicts a higher COG for /t̪/ than /t̻/.
Changes in Iu-Mien prevoicing: A focus on speakers in the middle
Authors: Thurgood Ela
Published: November 2016

The focus is on speakers who come from families of 8 to 10 children and are in the middle being the 4th or the 5th child in the family. This paper provides an acoustic analysis of syllable-initial Iu Mien stops produced by these speakers, comparing their stops with those of the older siblings. The distinction is important in that the oldest siblings are Iu-Mien native speakers and English non-native speakers, while the youngest siblings are English native speakers with only some passive knowledge of Iu-Mien. Those in the middle constitute a bridge between the other two groups. They are bilingual in both Iu-Mien and English; as the interviews attest, they regularly use Iu-Mien with their parents and older siblings, and English with their younger siblings. This study discusses in detail the differences in the VOT productions of /b p ph/ and /d t th/. It shows that the presence or lack of prevoicing divides those in the middle into two groups: those who prevoiced all of the 266 voiced VOTs measured, and those who prevoiced in 25-44%. The percentage of prevoicing is shown to correlate with language competence that influences language transmission.
Effects of phonetic naturalness in decay of Korean vowel harmony
Authors: Jang Hayeun
Published: November 2016

In this paper, based on Korean vowel qualities measured in the production experiments, I point out that /o/-stems are also actively participating in the decay of Korean vowel harmony, and their speed of decay is much faster than /a/-stems' speed. How the late-starter /o/-stems could have the faster speed in the decay of Korean vowel harmony? The role of phonetic naturalness in language learning is the key. Measured vowel qualities show that /o/ is acoustically much closer to /ʌ/ as “disharmonic” pair than to /a/ as “harmonic” pair. In addition, in terms of articulatory, the raising of /o/ and the backing of /ʌ/ make them more similar. In the production experiments, 14 Seoul-Korean speakers participated (7 males, 7 females). Onset and coda of stems are controlled. For each condition, 1 existing word and 2 nonce words are used. Participants are asked to make a natural conjugation form of a given stem and to produce it three times. Unlike previous corpus and production studies reporting that /o/-stems show no disharmonic forms, the current experimental results show that quality of selected vowels after /o/-stems is similar to /ʌ/, not /a/. Compared to /a/-stems, /o/-stems' suffix vowel qualities are clearly closer to /ʌ/.
Analysis of acoustic features for speech intelligibility prediction models analysis of acoustic features for speech intelligibility prediction models
Authors: Yamamoto Katsuhiko , Irino Toshio , Matsui Toshie , Araki Shoko , Kinoshita Keisuke , Nakatani Tomohiro
Published: November 2016

We have developed a new model to predict speech intelligibility of synthetic sounds processed by nonlinear speech enhancement algorithms. The model involves two recent auditory models: the dynamic compressive gammachirp (dcGC) auditory filterbank and the speech envelope power spectrum model (sEPSM). The dcGC-sEPSM was compared with commonly used prediction models based on perceptual intelligibility scores of speech sounds enhanced by classic spectral subtraction and state-of-the-art Wiener filtering. As a result, the dcGC-sEPSM predicted the scores better than the coherence SII (CSII), the short-time objective intelligibility (STOI), and the original sEPSM using the gammatone filterbank. There was, however, still inconsistency between the prediction and data. In this work, we show the analysis of acoustic features used in the prediction models. The CSII calculates the magnitude-squared coherence between clean and processed spectra to derive a signal-to-distortion ratio. The STOI calculates the correlation coefficients between the short-time frame vectors of clean and degraded sound at the output of the one-third octave filterbank. The sEPSM calculates the signal-to-noise ratio in the envelope modulation domain at the output of the auditory filterbank. We summarize the methods and discuss desirable features that improve speech intelligibility predictions.
Ultrasound tongue image denoising for comparison of first and second language tongue trajectories
Authors: Moriya Shusuke , Yaguchi Yuichi
Published: November 2016

The main purpose of this research is to specify articulation difference between native and non-native speakers by digitizing tongue motions and analyzing the difference between utterances. Differences in tongue motion directly influence speaker’s pronunciation; therefore, it may be possible to improve non-native speaker’s efficiency of pronunciation practice with the relevant feedback and visualization. It is necessary for comparison of native and non-native speakers’ tongue motions to that end, however, normalization is absolutely necessary to remove the influence of anything except tongue motion before comparison, because every person has a unique shape and size. In our previous research, we proposed normalization methods and some speaking errors were picked up automatically from tongue trajectory in ultrasound tongue image space. However, it is necessary to improve method to extract pure tongue trajectory with accuracy. In this paper, ultrasound tongue images are separated to 5x20 or 20x5 strip block. If tongue edge lies on the block, gray scale graduation forming a shape of an arch has occurred on a line of long side of block. We proposed some shape-sensitive filter to cut off an image noise which locates excepting neighborhood of tongue edge. Through our filter, tongue trajectory extracted from ultrasound tongue image could have less noises then previous one. However, some image noises locates on neighborhood of tongue edge are emphasized and inhibited comparison of native and non-native tongue trajectories.
Pitch estimation based on instantaneous robust algorithm for pitch tracking using weighted linear prediction-based complex speech analysis
Authors: Shan Wei , Funaki Keiichi
Published: November 2016

Pitch estimation plays an important role on speech processing such as speech coding, synthesis, recognition, and so on. Although current pitch estimation method performs well under clean condition, the performance deteriorates significantly in noisy environment. For this reason, robust pitch estimation against additive noise is required. Modified auto-correlation method is commonly used as pitch estimation in which LP residual is used to compute the auto-correlation. We have previously proposed pitch estimation methods based on Time-Varying Complex AR (TV-CAR) analysis whose criterion is the weighted correlation of the complex residual obtained by the TV-CAR analysis, sum of the harmonics for the complex residual spectrum, or so on. On the other hand, Azarov et al. have proposed an improved method of RAPT (Robust Algorithm for Pitch Tracking) using an instantaneous harmonics that is called IRAPT (Instantaneous RAPT). The IRAPT can perform better estimation than RAPT. Since IRAPT uses band-limited analytic signal to obtain harmonic frequencies, the complex residual signal obtained by the TV-CAR analysis can also be applied to the IRAPT. In this paper, novel pitch estimation method using the instantaneous frequency based on the robust WLP (Weighted Linear Prediction) TV-CAR residual is proposed and evaluated.
Investigation of nonlinearity parameter B/A of saturated, unconsolidated marine sediments via a statistical approach
Authors: Lee Hunki , Noh Eunghwy , Ohm Won-Suk , Kwon Oh-Cho
Published: November 2016

In this talk, we present a theory and the supporting experiment for the nonlinearity parameter B/A of saturated, unconsolidated marine sediments. The model is composed of the quadratic nonlinearity of the equivalent suspension of grains and the interstitial fluid and the nonlinearity resulting from the random grain contacts. To capture the random nature of grain contacts, the number of Hertzian contacts on each grain and the distribution of contact forces between grains are treated statistically. Predictions of B/A are compared with measurements performed with the finite amplitude insert-substitution (FAIS) method. Dependence of B/A on external compression and the incident sound pressure level is also discussed. [This work was conducted in the Unmanned Technology Research Center (UTRC) sponsored by the Defense Acquisition Program Administration (DAPA) and the Agency for Defense Development (ADD) in the Republic of Korea.]
Relationship of the difference of the speech rate of an announcement at the railway station and the listening impression
Authors: Tsujimura Sohei
Published: November 2016

The purpose of this study is to clear the influence of the speech rate of an announcement on the listening impression. In this study, a subjective experiment in which the elderly and the young adults participated was conducted in the simulated station. In this experiment, the speech rate of an announcement was varied from 4.5 to 9.5 mora/s at 1 mora/s interval, and subjective evaluations (“Listening difficulty,” “Loudness,” and “Strangeness”) of the announcements were made under three types of background noise conditions (LA 65 dB, 70 dB, and 75 dB). The relationships of the speech rate of an announcement and the subjective evaluation such as “Listening difficulty,” “Loudness,” and “Strangeness” were investigated, and the optimum speech rate of an announcement at the railway station was discussed. As a result, it was suggested that “Listening difficulty” has the lowest evaluation value when the speech rate is 6.5 mora/s or 7.5 mora/s. Furthermore, in this speech rate range, “Strangeness” as an announcement at the railway station was not felt. It was demonstrated that the optimum speech rate of an announcement at the railway station is in the range from 6.5 mora/s to 7.5 mora/s.
Acoustic feedback considerations in simulations of sound systems in rooms
Authors: Ahnert Wolfgang , Feistel Stefan
Published: November 2016

Computers are employed since about 30 years in the simulation of room- and electro-acoustics. Simulation tools have always considered sources, usually loudspeakers, but not microphones, which is the reason that acoustic feedback has not been considered by any simulation tool yet. As a new feature, a database for microphones is introduced analogous to the database of loudspeakers and other general sources. It is possible in this way to simulate the regeneration of sound over the close system loop, and estimate the maximum gain before feedback, and related influence on maximum sound pressure level and speech intelligibility. The paper briefly describes the important features of the new microphone database. Afterwards, the basic mechanism of acoustic feedback is explained, and the dependence of the feedback threshold of different sound sources and receivers as well as the acoustic properties of the room. By calculating the feedback threshold the headroom of the acoustic gain before feedback may be predicted. These threshold values are calculated by simulation and compared with measurements. This will be done for different loudspeaker-microphone arrangements in a selected conference hall.
The engineer in field biologist’s clothing: Whitlow Au’s academic years
Authors: Lammers Marc , Benoit-Bird Kelly
Published: November 2016

In 1993, the same year that The Sonar of Dolphins was published, Whitlow Au transitioned from the U.S. Navy’s Naval Ocean Systems Center to the Hawaii Institute of Marine Biology. Thus began a second professional act, so to speak, of field-based research and mentoring the next generation of marine bioacousticians. An electrical engineer doing field biology may not seem like the natural order of things at first, but the combination of Whitlow’s engineering and acoustic prowess coupled with the enthusiasm and energy of bright young biologists resulted in a powerful research team. Thanks to Whitlow’s ingenuity and commitment to advancing the state of the art, Hawaii’s coastlines and marine habitats around the world were explored like never before. A lack of funding or the availability of appropriate instrumentation were never an obstacle, but rather became opportunities for creativity and invention. Whitlow and his students’ research on dolphins, their prey, snapping shrimp, humpback whales, and other taxa led to many pioneering breakthroughs both in biology and technology. While Whitlow’s scientific legacy could be measured by his more than 200 publications, it is the hundreds of lives he influenced though his academic and professional service that will ultimately be his greatest mark.
Echolocation behavior of endangered fish-eating killer whales (Orcinus orca) recorded from digital acoustic recording tags (DTAGs): Insight into subsurface foraging activity
Authors: Holt Marla M. , Hanson M. Bradley , Emmons Candice K. , Giles Deborah A. , Hogan Jeffrey T. , Haas David
Published: November 2016

Killer whales are apex predators with diet specializations that vary among ecotypes. Resident killer whales use broadband echolocation clicks to detect and capture fish prey in their underwater environment. Here, we describe the echolocation behavior of endangered Southern Resident killer whales using DTAGs to determine subsurface foraging activity and to assess the effects of vessel and noise on foraging behavior. We deployed 29 DTAGs on individually-identified killer whales and collected complimentary field data over four seasons in summer habitat. DTAGs had two hydrophones that each recorded sound at sampling rates of 192 or 240 kHz, and other sensors to reconstruct whale movement. Prey remains were opportunistically collected during tag deployments to validate feeding. Echolocation signals of the tagged whale were inferred from spectral content and the angle of arrival that corresponded to tag placement. Preliminary results reveal that individuals produced steady click trains during shallow dives then dove to deeper depths while clicking at higher repetition rates that graded into bottom-associated low-level buzzes before ascent occurred. These results, together with movement data, are reliable subsurface foraging cues in this endangered population that can be used to assess vessel effects on foraging behavior.
Echolocation detection of fishing hooks and implications for the Hawaiian longline fishery
Authors: Pacini Aude F. , Nachtigall Paul E. , Smith Adam B. , Owens Rock , Vlachos Stephanie
Published: November 2016

Interactions between marine mammals and fisheries have a biological and economic impact that is often detrimental to both fishermen and species of concern. False killer whale bycatch in the Hawaii longline fishery has exceeded the potential biological removal (PBR) triggering the designation of a take reduction team under the Marine Mammal Protection Act (MMPA). As an attempt to understand the importance of acoustic cues in depredation events, this study presents preliminary data looking at the echolocation ability of a false killer whale (Pseudorca crassidens) to detect a longline fishing hook at various distances. Using a go/no-go paradigm, the whale was trained to report the presence of the hook at distances varying in 50 cm increments. A total of 28 sessions of 25 trials each were collected and echolocation signals were recorded using a nine element acoustic array. Number of clicks, acoustic parameters, decision time and performance were recorded. The subject successfully reported the presence of the hook up to 6 m. This work presents evidence that false killer whales can easily detect fishing gear which could influence how they interact with longline fishery.
Transmission beam characteristics of a spinner dolphin (Stenella longirostris)
Authors: Smith Adam B. , Pacini Aude F. , Nachtigall Paul E. , Suarez Leo , Aragonez Lem , Magno Carlo , Laule Gail , Kloepper Laura N.
Published: November 2016

Transmission beam characteristics have been described in a small number of odontocete species, providing insight into the biological and ecological factors that have influenced the design of the outgoing echolocation beam. The current study measured the on-axis spectral characteristics and transmission beam pattern of echolocation clicks from a small oceanic delphinid, the spinner dolphin (Stenella longirostis). A formerly stranded individual was rehabilitated in captivity and trained to station underwater in front of a 16 element hydrophone array. Preliminary analysis of a subset of recorded clicks showed on-axis spectral characteristics with a mean center frequency of 68 kHz and a mean peak frequency of 52 kHz. The dolphin exhibited both a circular beam shape and also varying degrees of a dorso-ventrally compressed transmission beam. The mean angular beamwidth for all clicks was 16.6 and 14.3 degrees in the horizontal and vertical planes, respectively, though some clicks exhibited horizontal beamwidths that were almost twice as wide as the vertical beamwidth. The overall beam was generally broader than the beams of previously described species, with a mean directivity index for all clicks of 21.5 dB. These results are the first reports of transmission beam characteristics from a spinner dolphin.
Deep water sound sources for ocean acoustic tomography and long-range navigation
Authors: Morozov Andrey K. , Webb Douglas C.
Published: November 2016

The first test of the tunable organ-pipe was successfully conducted on 11 Sept. 2001. The sound source was efficient, powerful, and had unlimited operational depth, as well as a minimum level of high frequency harmonic content. The projector uses a narrow-band, highly efficient sound resonator, which is tuned to match the frequency and phase of a reference frequency-modulated signal. Since 2001, many deep-water ocean acoustic experiments have used this type of sound source. The source was successfully used for ocean acoustic tomography and long range navigation. Recently, it was shown that a bottom-deployed swept frequency array can be used for high-resolution seismic imaging of deep geological formations. The long-term operating experience of the sound sources demands the development of an improved sound source system. A finite-element analysis that shows the structural acoustics of the tunable resonator has been conducted to improve the acoustics of the sound source. The analysis gave a better solution for a tuning mechanism with an octave frequency range. The development of the electric and mechanical systems of the sound source will be discussed. Teledyne Marine Systems continues innovating promising solutions for ocean acoustic tomography, navigation, and seismo-acoustic applications.
Passive elastography: A seismo-inspired tomography of the human body
Authors: Catheline Stefan
Published: November 2016

Elastography, sometimes referred as seismology of the human body, is an imaging modality recently implemented on medical ultrasound systems. It allows to measure shear waves within soft tissues and gives a tomography reconstruction of the shear elasticity. This elasticity map is useful for early cancer detection. A general overview of this field is given in the first part of the presentation as well as latest developments. The second part, is devoted to the application of noise correlation technique in the field of elastography. The idea, as in seismology, is to take advantage of shear waves naturally present in the human body due to muscles activities, heart beating, and arteries pulsatility to construct shear elasticity map of soft tissues such as the liver, the thyroid, or the brain. It is thus a passive elastography approach since no shear wave sources are used.
Quantitative diagnosis method based on model of tissue structure change for liver fibrosis
Authors: Hachiya Hiroyuki , Hirata Shinnosuke , Yamaguchi Tadashi
Published: November 2016

To realize a quantitative diagnosis method of liver fibrosis, we have been developing a modeling method for the probability density function of the echo amplitude. We developed a scatterer distribution model of diseased livers considering the liver lobule structure, because computer simulations are effective for obtaining information on the continuous stage of diseases. We examined relationship between tissue characterization and ultrasonic B-mode image which is simulated by this scatterer distribution model. From these analyses, we proposed a multi-Rayleigh model with three Rayleigh distributions, corresponding to the distribution of the echo amplitude from hypoechoic, normal, and fibrous tissues. We showed quantitatively that the proposed model can model the amplitude distribution of liver fibrosis echo data adequately. We also found that fibrous indices can be estimated stably using the proposed model. To evaluate the liver fibrosis more accurately, each pixel's amplitude value in the clinical echo image was transformed into the fibrotic probabilities by using the multi-Rayleigh model. Clinical echo images of liver fibrosis were analyzed, and the relationship between those probabilities and the stage of liver fibrosis were discussed. We conclude that the proposed method is valid for the quantitative diagnosis of liver fibrosis.
Speed of sound, attenuation, and acoustic impedance of hepatic lobule in diseased rat liver observed by scanning acoustic microscopy with 250 MHz
Authors: Yoshida Kenji , Deng Zhihao , Ito Kazuyo , Mamou Jonathan , Maruyama Hitoshi , Hachiya Hiroyuki , Yamaguchi Tadashi
Published: November 2016

Based on the analysis of echo amplitude envelope and power spectrum of backscattering echo, our group has attempted the characterization of various types of tissue such as liver, lymph node, and skin. For example, the scatterer size estimation of rat liver showed that the estimated size was 30-50 μm. However, it was not investigated how the obtained parameters related to the histology in detail. To resolve this problem, it would be invaluable to understand the spatial distribution of acoustic properties, e.g., speed of sound, attenuation, and acoustic impedance in the scale from micro- to millimeter range. Thus, we measure and accumulate the data using ultrasound with center frequency of 1- 500 MHz. This report introduces the acoustic properties of specimen prepared from two different types of rats: normal liver and liver fibrosis models. A scanning acoustic microscopy using 250-MHz ultrasound with spatial resolution of 7 μm was employed. After the measurement, H&E staining and Masson trichrome staining were conducted to obtain histology. Image registration of SoS image and histology image enabled to separately evaluate SoS of cell nucleus, cytoplasm, and fibrotic tissue. The result demonstrated that there was no significant difference in SoS among cell nucleus, cytoplasm, and fibrotic tissue.
Cultured tumor model inspection for anticancer drugs using acoustic impedance microscope
Authors: Yoshida Sachiko , Rahayu Rahma H. , Takanashi Kyoichi , Kishikawa Kenta , Kurita Hirofumi , Takashima Kazunori , Hozumi Naohiro , Kobayashi Kazuto , Yamamoto Seiji
Published: November 2016

High-frequency ultrasonic microscope is useful to observe intracellular structure of cultured living cells. We have observed the dynamical change of intracellular actin filaments in several cells, and reported the difference of stabilities between cancer cells and ordinary cells. The dynamics of actin filaments are deeply related to cancer cell viability. In this study, we applied this acoustic microscopy to antitumor drug screening. One of the cultured brain cancer models was established with both normal glial cells and C6 glioma cells. Normal glial cells were labeled by endogenous fluorescent protein to be identified. Both cells were co-cultured on a 75 micrometer-thick polystyrene substrate. Acoustic pulse wave with 320 MHz was focused on the interface between the cell and the substrate, and sent through the substrate. Either classical anticancer drug, cytochalasin B, or novel clinical anticancer drug, temozolomide, was applied to the cultured cancer model, and observed their intracellular acoustic changes using the acoustic microscope. Before and after drug treatment, the cultures were observed with the laser confocal microscopy to confirm survival of each cell. Another of the models was established with fluorescent protein-labeled breast cancer cells. Our model system would be useful to inspect anticancer drugs without whole animals.
Arrangement of control points for sound spot generation in the multi-point control method
Authors: Yasueda Kazuya , Shinjo Daisuke , Kataoka Akitoshi
Published: November 2016

In this research, we considered control point arrangement by using small-scale linear loudspeaker array. The multi-point control method is proposed for sound reproduction in a limited area/direction. This method is based on boundary surface control principle. The desired signal is reproduced in the target point by the sound pressure control in the control points. According to the MINT (multiple-input/output theorem), the signal is reproduced with accuracy in the target point if the number of sound sources more than the number of control points exists. However, a lot of speakers make it difficult to use in real environment. Therefore, small-scale loudspeaker array is preferable. If the number of control points is greater than the number of sound sources, the filter coefficient is approximated by the least squares-method. This approximation affects the sound pressure suppression and sound quality depending on the arrangement of control point. We examined the number of control points arranged. The input signal is the speech signal that has 300-3400 Hz frequency band. We evaluated some arrangement pattern by sound pressure, SD (Spectral Distortion), and PESQ (Perceptual Evaluation of Speech Quality). As a result, good results were obtained than conventional arrangement.
Large-scale loudspeaker array system for sound field reproduction using high-speed 1 bit signal processing
Authors: Yamanaka Yusei , Takeuchi Daiki , Kuze Dai , Ikeda Yusuke , Oikawa Yasuhiro
Published: November 2016

Recently, many techniques of physical sound field reproduction, such as Wave Field Synthesis, Higher Order Ambisonics and Boundary Surface Control, have been studied. Since the number of loudspeakers generally increases to control with higher spatial resolution and higher frequency, the system becomes too complicated to be constructed. On the other hand, high-speed 1 bit signal processing has been studied widely. The 1 bit audio system has interesting features such as simple circuit implementation, simple signal transmission, and no D/A converter. In this study, we proposed the large-scale loudspeaker array system with high-speed 1 bit signal. The system consists of a master and hub systems with sample rate of 4 MHz. The master system reads multi-channel 1 bit signal from SSD and transmits it to each hub system. Each hub system drives 32 loudspeakers by CMOS drivers. The master and each hub system are connected with a LAN cable to implement only hub system near the loudspeakers. It is easy to scale the size of system with flexibility thanks to the simplicity of the circuit and signal flow. We conducted preliminary experiments to control its sound directivity. In the future, we are planning to construct 1536-channel sound reproduction system with our proposed system.
Evaluation on overlapping barriers design using SoundPLAN
Authors: Sun Sheying , Morozumi Neil , Patching Richard
Published: November 2016

Traffic noise comes along with road developments. To overcome traffic noise problems, noise barriers, low noise pavements, low noise vehicles, traffic control measures, and proper land uses have been proposed. Being considered to have great benefits of easy installation, better noise reduction performance, and ability to soothe annoyed residents, noise barriers have become the most prevalent noise control measures adopted by most agencies. However, any defects in noise barriers may allow unnecessary noise propagation and thus degrade their performance. Consequently, noise barriers should be constructed and maintained with care to uphold their designed noise reduction capability. Overlapping barriers are sometimes necessary for maintenance or community access. There is apparently a need to evaluate the effect of the performance of overlapping barriers. Inappropriate design may cause severity of degradation of acoustical effectiveness. Acquiring the appropriate parameters of the overlapping barrier design will serve as a reference for decision makers to properly allocate the gap location and select the sound design. This analysis focuses on the evaluation of barrier overlapping design and receiver regions in the vicinity of an overlap gap using the SoundPLAN software package. The contributions from the various parameters such as materials, barrier height, gap, and overlapping sizes were investigated.
Numerical investigation on radiation characteristics of aero-intake noise with ground effects
Authors: Choung HanAhChim
Published: November 2016

A hybrid method for the prediction of far-field Aero-intake noise from gas turbine engine with ground effects has been developed. The near-field predictions were obtained by solving the linearized Euler equations with computational aeroacoustic techniques composed of high-order finite difference scheme, non-reflecting boundary condition, overset grids, and parallel computational methods. Kirchhoff integral method was used for the prediction of far-field directivity patterns. In order to predict the noise propagation, ray theory is applied with Geographical Information System (GIS) terrain profile data. Then, the noise level on the ground has been predicted and analyzed, including the effects of air absorption, ground reflection, and diffraction.
Multi-physics modeling of conformal, solid-state, and thin-film thermophones
Authors: Asgarisabet Mahsa , Barnard Andrew R.
Published: November 2016

Thin-film thermophones are thermoacoustic loudspeakers made from new materials such as aligned carbon nanotubes or graphene. They are solid state devices, in that there are no moving parts associated with the sound generation mechanism. Lumped parameter models have been developed for planar thermophones and agree well with experimental results. One benefit of thin-film thermophones is that they can be designed such that the transducer can be conformal to complex geometries. However, the lumped parameter models are not appropriate for complex geometries or electrical/thermal transients. An electrical-thermal-acoustic multiphysics model of these transducers has been created using COMSOL Multiphysics to address the issues present with the lumped parameter models. Development and validation of the model will be discussed.
String-pressing force of Japanese Koto
Authors: Ando Tamaki , Obata Satoshi , Aiba Eriko
Published: November 2016

The koto is a traditional Japanese stringed musical instrument and is similar to the zither. The koto typically has 13 strings and is played by plucking the strings using three fingers (thumb, index, and middle fingers) with picks. Each string is strung over a movable bridge, and the support point can be changed by adjusting the position of the bridge. As the distance between the support point and the right end of the string determines a pitch, the koto is tuned by adjusting the bridge position. In addition, players can change the pitch by pressing the string with their left hand. This technique is called oshide and it is important but difficult to apply accurately for koto players. The subjective difficulties of oshide change depending on the position of the strings (on the near or far side of a player’s body), string’s material (silk or polyester), condition (old or new) of the string, and so on. In order to ensure good-quality performance, expert koto players modify their string-pressing manner. However, there are no previous studies on this. In this presentation, we present our results of the string-pressing force applied by koto players using oshide under various conditions.
Modes of vibration of a sheng reed
Authors: Kirk Thomas W. , Cottingham James P. , Sindelar Eric
Published: November 2016

The sheng is an Asian mouth organ consisting of a number of bamboo pipes enclosed in a wind chamber with brass free reeds at the end of each pipe inside the chamber. The reed in each pipe typically includes a small wax tuning weight near the free end of the reed tongue. The determination of modes of vibration of these reeds, especially how the tuning weight changes those modes of vibration, is the topic of this paper. Recent research has investigated the acoustics of sheng pipes and compared the measured impedance of sheng pipes augmented with pipe resonators with a theoretical model. This research employs finite element analysis software to construct a theoretical model of sheng reeds and compare that model with measured vibrational analysis data gathered with a laser vibrometer. The primary emphasis is on how well the predicted resonance frequencies compare with measured resonance frequencies of the reed as indicated in a response curve. Also compared are the predicted nodal and antinodal positions along the length of the reed with the measured nodal positions. [Research supported by National Science Foundation REU grant PHY-1004860.]
Organologic and acoustic similarities of the European violin and the Chinese erhu
Authors: Pfeifle Florian
Published: November 2016

The Chinese erhu is a bowed spike lute with a recorded history dating back to the Song dynasty (960-1279). It is played in different sociocultural as well as musical settings and in different styles of Chinese music. In modern Chinese orchestras it fills the part of the lead voice in the bowed instruments section, comparable to the role of the European violin in classical orchestras. Even though the design of both instruments differs in several central aspects, they exhibit structural and acoustical similarities. In this work, organologic as well as acoustical similarities of both instruments are highlighted with a special focus on the excitation mechanisms of both instruments. To this end, a set of measurements using high-speed camera recordings of the bowing and the string motion are evaluated and compared. Differences in the resulting “Helmholtz” motion are explained and attributed to the specific string attachment and the structure of the bow respectively. Timbre similarities are shown for several different bowing gestures and the expressive palette of both instruments is compared. Organologic similarities are highlighted through an analysis of the historical evolution of structural components of both instruments again with a strong focus on the bow.
Review of the 2016 Edition of ANSI S12.6 and its place in the panoply of standards on the measurement of real-ear attenuation at threshold since 1957
Authors: Berger Elliott H.
Published: November 2016

The American standard specifying the procedure for the measurement of real-ear attenuation at threshold (REAT), often termed the gold standard in measuring hearing protector attenuation, was recently approved as an updated version, ANSI 12.6-2016. REAT was first standardized worldwide in the late 1950s in an American standard ANSI Z24.22-1957 and the method has evolved with time. Changes have affected the electroacoustic requirements for the sound field, instrumentation, audiometric method, and permissible background noise, but more importantly have also improved the specification of how the experimenter works with and fits the test subjects. So too, estimates of uncertainty are now included, and in the 2016 version they have been clarified and brought into harmony with ISO 4869-1. The author, who has been the chair since 1985 of the ANSI working group responsible for S12.6, will compare and contrast the various methods and present representative data as well as a discussion of the expanded uncertainties that are specified. Those values, for the 1/3-octave band test bands from 125 Hz to 8000 Hz, vary from approximately 1.5-2 dB for earmuffs and 2-3 dB for earplugs for within-laboratory testing, to 4-6 dB for earmuffs and 6.5-8 dB for earplugs for between laboratory measurements.
Modeling the effects of hearing protection on speech recognition as function of noise level and hearing status
Authors: Giguère Christian , Berger Elliott H.
Published: November 2016

The ability to communicate verbally when wearing hearing protectors is an important aspect to consider for compliance in the use of these devices as well as for safety and operational efficiency in the workplace. Speech recognition with hearing protectors is influenced by many factors such as the overall amount of noise reduction, the slope of the attenuation-frequency function and the presence of hearing loss [Giguère and Berger, Int. J. Audiol. 55, S30-S40 (2016)]. Interestingly, results from subjective and modelling studies sometimes show a benefit of using passive hearing protectors on speech recognition in noise compared to unprotected listening, especially with normal-hearing individuals in high-noise levels. The purpose of this modeling study is to further explore the conditions promoting such a facilitative effect of hearing protectors on speech recognition, with a particular attention to the noise level in the environment and the hearing status of the user. This information is important to better guide the selection of the most appropriate hearing protection device, given the characteristics of the user and workplace noise.