bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficient estimation and compensation of Doppler shift for multicarrier signals in underwater acoustic communications
Authors: Karanam Saraswathi , S Ravi Shankar
Published: November 2016

Orthogonal frequency division multiplexed (OFDM) carriers are well studied in literature for their ability to tolerate multipath effects in the presence of ambient noise in an underwater acoustic (UWA) channel. However UWA Doppler destroys the orthogonality of subcarriers, resulting in severely degraded Signal to Noise ratio (SNR). To mitigate this effect, we present a novel method for Doppler estimation and compensation over this channel. This method involves transmitting a training preamble of up to three OFDM symbols. Doppler estimation is carried out based on a sliding window correlation over an OFDM symbol period between the received and local copy of time samples. After rejecting spurious peaks, the correlation values are normalized and existence of Doppler detected when the correlation value exceeds a set threshold. The Doppler shift is then estimated post FFT. Specifically the phase angle of received pilot samples is averaged over three OFDM symbols. This estimated shift is used to compensate the Doppler shift in the following received data symbols. Simulations have been performed for different Doppler shifts over an UWA multipath channel, with BER as a parameter. Significantly, the approach avoids resampling and the need for buffering received data packets. This method also reduces computational complexity significantly.
Low frequency beamforming in shallow water environments
Authors: Abadi Shima , Amaratunge Cole , Boyd Gavin , Daniels Matthew
Published: November 2016

Ray theory is a high frequency approximation of the wave equation solution. Beamforming is a spatial filtering method that uses the ray theory to estimate the arrival angle from the array recordings. However, the ray theory is restricted to situations where water column is much deeper than the propagated wavelength and fails when water depth is smaller compared to the acoustic wavelength (i.e., in shallow-water low-frequency propagation). In this situation, the underwater sound propagation is modeled by normal-modes theory, the exact solution of the wave equation. In the theory of normal modes, each mode propagates at a different incident angle and the total field is composed of a discrete sum of the propagation modes excited at the broadcast frequency. In this situation, the beamforming performance degrades because of the interference between individual mode incident angles. In this presentation, the performance of the conventional beamforming technique is investigated when low frequency signals are propagated in shallow water environments and recorded by either a vertical or a horizontal linear array of hydrophones. Simulations are undertaken to understand how the resolved angle from the conventional beamforming method is related to the bearing angle and the incident angle of each mode.
Calibration of the matched filter beam output from the triplet portion of the Five Octave Research Array
Authors: Ellis Dale D. , Yang Jie
Published: November 2016

The Five Octave Research Array (FORA) [K.M. Becker and J. R. Preston, Proceedings Oceans 2003, 2607-2610] includes a triplet section in which the elements are three omnidirectional sensors. The elements can be combined as a standard linear array to produce conical beam patterns, or the triplets can be used to form directional beams that allow for “left-right” discrimination. The beam output can then be matched filtered to produce high-temporal-resolution beams over the full 360° azimuth, and identify scattering features in reverberation data. To extract scattering strengths, the calibration of the beams and the matched filter output must be known accurately. Here we look at results from the 2013 Target and Reverberation Experiment (TREX13), where data were received on the FORA array, then beamformed and matched filtered by various procedures that had different normalizations. The broadside beam and several natural beams of the linear array can readily be calibrated against a simple “exact” procedure. No simple procedure was obtained for the directional beams, but comparisons of the peaks of the features in the left and right triplet beams compare well with the peaks of the linear beams.
Source localization in underwater waveguides using machine learning
Authors: Niu Haiqiang , Gerstoft Peter
Published: November 2016

The problem of underwater acoustic source localization is solved using an artificial neural network (ANN) under the machine learning framework. Source localization in a waveguide is posed as a classification problem by training a feed-forward neural network (FFN) with one hidden layer. In this paper, the acoustic pressure signals received by a vertical linear array are preprocessed by constructing the normalized cross-spectral density matrices (CSDM), which are used as input of the FFN. Each unit of the output layer represents one possible range (Here, for simplicity, source range is the only parameter that needs to be determined). Different from model-based localization methods such as matched field processing (MFP), ANN as a data-driven method can learn features from real acoustic data, thereby bypassing the sound propagation modeling step completely. Simulations show that FFN achieves a good performance in determining the source ranges even with deficient training data samples and low signal-to-noise ratios (SNRs). The validity of FFN in source localization is further demonstrated with vertical array data from Noise09 experiment where the ship is located successfully using FFN.
Estimating seabed structure from perturbed layer resonance fringes
Authors: Holland Charles W.
Published: November 2016

Waves reflecting from layered media give rise to constructive and destructive interference fringes. These well-known fringes occur at integer multiples of half- and quarter-wavelength conditions respectively. When any of the layer boundaries are rough, the fringe pattern is perturbed. One class of observed perturbations is when the when the fringe exhibits a stair-step pattern in frequency and angle, instead of the smooth behavior predicted by theory. These perturbations can lead to difficulties for statistical inference when using the flat layer assumption. First, the physics behind the stair-step perturbations are described. Then, from the physics we show how to estimate or bound small-scale roughness parameters from the stair-step perturbations. Both simulations and measured data are employed to probe the information content of reflection data for small-scale roughness in layered media. [Research supported by the ONR Ocean Acoustics Program.]
Volume scattering from turbidite sequences
Authors: Olson Derek R. , Holland Charles W.
Published: November 2016

The seabed environment near continental margins is commonly composed of turbidite sequences, which are alternating layers of silt/sand and pelagic clay (mud). Scattering can occur both from interface roughness structure, as well as volume heterogeneities within each layer. A modeling technique is detailed that takes into account the layering structure of a turbidite for propagation into and out of the sediment, and uses the Born approximation to model the scattering. This model properly accounts for effects of the layering structure on the incident field (instead of using an effective medium approximation), which is expected to be important particularly at high frequencies (relative to the scales of the layering). Model results from several types of environments will be shown, and also compared to bottom scattering data collected in the Ionian sea.
Measurements and predictions of surface Doppler and arrival time spread in a variety of wind conditions
Authors: Walstead Sean
Published: November 2016

Measurements from a bistatic surface scattering experiment are presented. Acoustic waveforms in the 200 kHz—400 kHz (VHF) frequency regime were transmitted and received in a variable speed wind wave channel at the Scripps Institution of Oceanography. Physics based analytic predictions for Doppler shift and arrival time spread are compared to experimental measurements. The effect of source/receiver depth and surface wave shape on acoustic properties of the surface multipath are quantified as a function of wind speed. The importance of transmit waveform Doppler sensitivity of common underwater communications signals is quantified for various surface scattering regimes. This work has direct application to the improved performance of phase coherent underwater acoustic communications systems and the remote sensing of gravity-capillary waves.
Airport Cooperative Research Project 02-51: Evaluating methods for determining interior aircraft noise levels
Authors: Waldeck Randy , Schomer Paul , Freytag John
Published: November 2016

This paper documents the results of a study of acoustical testing methods used to quantify facade noise reduction measurements for airport sound insulation programs. The research was performed for the National Academy of Sciences as Airport Cooperative Research Project (ACRP) 02-51. Field measurements, in combination with acoustical calculations, were used to determine which methods are best suited for airport sound insulation programs. Loudspeaker (i.e., exterior elevated, exterior ground level, and interior), flyover, and sound intensity measurements were conducted throughout the United States. In addition, air infiltration measurements and noise reduction calculations were made. Results from each method were analyzed and compared. An analysis of each method's margin of error is presented, along with Best Practices for each method. Finally, a decision matrix for selecting the appropriate acoustical testing method is included.
Examining the temporal structure and information entropy of leopard seal calling bouts
Authors: Buck John R. , Rogers Tracey L.
Published: November 2016

Leopard seals (Hydrurga leptonyx) produce sequences of stereotyped sounds, or bouts, during their breeding season. The seals share common sounds but combine them in individually distinctive sequences. This study examines the underlying structure of the calling bouts by estimating the information entropy of the sound sequences with three entropy estimators. The independent identically distributed (IID) model estimates entropy from the simple frequencies of each sound. The Markov model estimates entropy from the frequency of pairs of sounds. Finally, the nonparametric sliding window match length (SWML) estimator exploits a relationship between the information entropy and the average subsequence match length. A better model for a given sequence achieves a lower entropy estimate. This study analyzed the calling bouts of 35 leopard seals recorded during the 1992-1994 and 1997-1998 Antarctic field seasons. The decrease of entropy estimates between the IID and Markov models for all seals analyzed confirmed the presence of temporal structures in the bouts. For twenty-one of thirty-five seals, the SWML entropy estimate was not significantly less than the Markov estimate, suggesting that a first-order Markov model accurately represents the structure of their bouts. [Work supported by the Australian-American Fulbright Commission and the Australian Research Council.]
Temporal patterning differences in contact calls among odontocetes’ species
Authors: Morisaka Tadamichi
Published: November 2016

Contact calls in odontocetes (toothed whales) have information of individual identity or group identity. Sound types used for contact calls, however, differ among species. Signature whistles in bottlenose dolphins, which are thought to function as “names” in human, are tonal sounds, whereas PS1 calls in beluga whales are pulsed sounds. Both signature whistles and PS1 calls have usually exchange pattern that calls are followed by calls by other individuals within around 1 second. Dolphins tend to produce next call when no individuals call back. Contact calls are usually produced repeatedly in a bout. Moreover, signature whistles often include multiple loops, sometimes with breaks between loops. The duration of breaks between loops is different between bottlenose dolphins and Indo-Pacific bottlenose dolphins. These results suggest that temporal patterning in contact calls in odontocetes is important for species identity.
Stereotypy and variability differ between humpback whale (Megaptera novaeangliae) phrase types offering structural support for the hypothesis that song is multi-message display
Authors: Murray Anita , Dunlop Rebecca A. , Goldizen Anne W. , Noad Michael J.
Published: November 2016

Humpback whale studies support inter- and/or intrasexual song functions, suggesting dual functionality. Some animals produce multi-message displays with dual functionality. Stereotyped components, for mate attraction and/or male-male interactions, convey species/group membership. Variable components, for courtship, convey male quality. If humpback whale song is a multi-message display, then song should include both stereotyped and variable components. Recordings of east Australian males (2004:8, 2011:9) were used to investigate this hypothesis. Song comprises “units” arranged into sequences (“phrases”) that are repeated (“themes”). Themes are characterized by different phrase types. Variation among phrases repeated within a theme (“phrase variants”) is mostly overlooked by other studies. Whether some phrase types are more variable than stereotyped is unknown. To assess this, repertoire size (number of unit types and phrase variants) was determined per phrase type. Whether phrase variants were unique to individuals or shared were also determined. Unit types were defined by self-organizing maps. Levenshtein distances between phrases with cluster analyses determined phrase types and phrase variants illustrating a novel application of these methods. Stereotypic phrase types contained shared phrase variants and limited repertoire. Variable phrase types contained unique phrase variants and large repertoire. These results support the hypothesis that song is a multi-message display.
Emergent pattern and underlying process: The what, why, and how of fish schooling
Authors: Parrish Julia K.
Published: November 2016

Over half of the world's fish aggregate at some point in their lives. As larvae, juveniles and/or adults, fish assemble into dense three-dimensional groups that last hours to lifetimes. The largest single stock fisheries in the world—anchoveta in Peru and pollock in the Bering Sea—are schooling fish. At several times the entire world's fish catch, the myctophid aggregations making up the deep scattering layer form the world's largest school. But are all schools alike? Are the “rules of fish schooling” at the scale of the individual the same across all species? Do different rules produce similar emergent pattern scaled up to the group, population, and ecosystem? Could differences across these scales from individual behavior to population response be determined acoustically, allowing technology to inform behavior, ecology, and conservation? This talk explores the diversity of ways that fish assemble, fiss and fuse, and disaggregate on a daily, seasonal, and annual basis through three related lens: the patterns of schooling, reasons why fish school, and analysis of how fish maintain the physical structure of the school.
Effects of target strength variability on estimates of abundance: The case of Atlantic mackerel (Scomber scombrus)
Authors: Scoulding Ben , Gastauer Sven , MacLennan David , Fässler Sascha , Copland Phillip , Fernandes Paul
Published: November 2016

Atlantic mackerel is a small pelagic, migratory fish which supports valuable commercial fisheries. Despite the fact that these fish school in massive numbers, and are readily detected using echosounders, fishery-independent estimates of the abundance of mackerel in the Northeast Atlantic do not yet consider acoustic data. Echo-integration surveys could provide annual estimates of abundance, with additional scope for studying mackerel distributions throughout the year. However, as in all acoustic surveys, this requires accurate estimates of target strength (TS). The present study provides in situ TS estimates for mackerel from measurements made at sea with a multi-frequency split-beam echosounder. Empirical results suggest mean TS of -51.22 dB at 18 kHz, -59.83 dB at 38 kHz, -55.51 dB at 120 kHz, and -53.43 dB at 200 kHz, for a mean fish length of 33.3 cm. These differ significantly from the values currently used in acoustic surveys. The sensitivity of mackerel abundance estimates to variations in TS estimates was investigated using data from a dedicated mackerel acoustic survey. Total stock biomass estimates at 38 and 200 kHz were in very good agreement with each other (to within 2.2%) and were in the range of values from an independent (i.e., non-acoustic) mackerel stock assessment. It is recommended that future acoustic estimates of mackerel are based on integration at 200 kHz.
Using echoview software to characterise acoustic scattering by aquatic organisms: The case of Atlantic mackerel (Scomber scombrus)
Authors: Jarvis Toby , Scoulding Ben
Published: November 2016

In a separate presentation, Scoulding et al. describe the rationale and foundation for regular acoustic surveys of Atlantic mackerel (Scomber scombrus) in the northeast Atlantic Ocean. Two key aims of this work were (1) to obtain a good knowledge of the in situ target strength of these weak scatterers, and (2) to settle on a robust and efficient workflow for the processing of mackerel acoustic survey data. To achieve these aims, dedicated mackerel acoustic surveys were carried out in 2012 and 2014 around the Shetland Islands, Scotland, and the data were processed using Echoview software. In this software-focused presentation, we provide details on how the multifrequency single-beam echosounder data were processed, and we discuss this in the context of a general workflow for acoustic data processing that can be considered for any type of echosounder and application. The aim is to provide specific usage examples of some of the powerful features of Echoview and to provide general guidance for those who use or who are considering using Echoview to characterise acoustic scattering by aquatic organisms.
History of biomedical ultrasound microscope in Japan
Authors: Saijo Yoshifumi
Published: November 2016

Floyd Dunn greatly contributed to the history of biomedical ultrasound microscope (USM) in Japan. Ten years after the concept of ultrasound microscope was proposed by Sokolov of Soviet Union, he realized the ultrasound absorption microscope in 1959. During the time he directed the Bioacoustics Research Laboratory at the University of Illinois, many Japanese researches stayed in his laboratory. Especially, the researchers from Tohoku University learned both technology and philosophy of USM and they started development of scanning acoustic microscopy for medicine and biology in 1982. The USM system had been used for nearly 30 years until the Great East Japan Earthquake destroyed the system. Not only USM, other high frequency ultrasound imaging was also developed in 1990s. Especially, clinical application of intravascular ultrasound filled a gap between several MHz ultrasound used in conventional B-mode and 100 MHz used in USM. High frequency technology and computer science helped developing new generation USM such as ultrasound impedance microscope and 3D ultrasound microscope. Now the application area is spread and Biomedical Ultrasound Microscope Conference is biannually held in Japan. Now, we thank Floyd again for the fruitful activity of USM in Japan.
Cavitation in therapeutic ultrasound: To be avoided or to be utilized
Authors: Umemura Shin-ichiro , Yoshizawa Shin , Takagi Ryo
Published: November 2016

Nearly three decades ago, I spent a kind of sabbatical year in Bioacoustic Research Laboratory, University of Illinois, which was supervised by Professor Floyd Dunn. Human knowledge and technologies on acoustic cavitation were significantly limited at that time compared to now. As the result, acoustic cavitation was considered to be avoided even in therapeutic applications of ultrasound. However, I was thinking that it should be utilized and had discussions with him on it, who was the expert on bioeffects of ultrasound including those induced by cavitation. Human technologies on acoustic cavitation have been advanced since then mainly in two aspects: 1) ultrasonic as well as optical observation of cavitation microbubbles at a high frame rate, and 2) generation of a short ultrasonic pulse at extremely high amplitude. A high speed camera had made possible to observe that a short extremely high-amplitude pulse can generate cavitation microbubbles localized near the ultrasonic focal point without inducing their chaotic generations at least in water. High frame rate ultrasonic imaging have made possible to confirm the localization in biological tissue during the therapeutic focused ultrasound treatment. In-vivo as well as ex-vivo experimental results evidencing those will be shown and discussed in the paper.
The interaction of pulsed ultrasound with mammalian lung
Authors: Miller Douglas
Published: November 2016

The impedance difference for a water-air interface yields virtually complete reflection for ultrasound, which coincidentally delivers an acoustical radiation surface pressure (ARSP). ARSP may be a physical mechanism for pulmonary capillary hemorrhage induced by diagnostic ultrasound. Fundamental tissue parameters in biomedical acoustics are the density ρ, speed of sound c, and the resulting acoustical impedance z=ρc. Many tissues are similar to water (z = 1,628 krayl), but not lung. The gas content of lung imparts an extreme heterogeneity with air having z = 0.424 krayl. If the lung surface is modeled simply as a water-air interface, then the ARSP is maximal. During a diagnostic ultrasound pulse, ARSP can be comparable to the pulmonary capillary blood pressure, thus adding stress to capillaries. However, the bulk properties of the lung are different from air. One of the few reports on acoustical properties of lung was by Floyd Dunn (JASA 1986;80:1248). Consideration of these bulk properties of lung tissue yields a much higher z ≈ 336 krayl at 2.8 MHz, and indicates substantial transmission of ultrasound through the pleura (O’Brien et al. JASA 2000;108:1290). This model suggests a reduced ARSP, and the potential involvement of additional mechanisms for capillary injury within the pulmonary interior.
Quantitative fibrotic imaging based on multi-Rayleigh model for ultrasound B-mode image of liver fibrosis
Authors: Mori Shohei , Hirata Shinnosuke , Yamaguchi Tadashi , Hachiya Hiroyuki
Published: November 2016

A quantitative diagnostic method for liver fibrosis using ultrasound B-mode image is highly required. To quantitatively evaluate liver fibrosis using ultrasound B-mode image, we have been focusing on the echo amplitude distribution properties. A probability density function (PDF) of echo envelope from a normal liver can be approximated by a Rayleigh distribution; however, the PDF of echo envelope from a fibrotic liver deviates from the Rayleigh distribution. To approximate the PDF of liver fibrosis, we have been proposing the multi-Rayleigh model which is a combination of Rayleigh distributions with different variances. By using the multi-Rayleigh model, the ultrasound B-mode image of liver fibrosis could be converted to the quantitative fibrotic probability image. In this study, we applied the fibrotic probability imaging method to clinical data which is classified into F0 (normal liver), F1 (early-stage hepatitis), F2 (moderate hepatitis), and F3 (late hepatitis) in accordance with a new Inuyama classification. First, a region of interest (ROI) was automatically selected based on the amplitude distribution property. Then, removal method of nonspeckle signals was used to improve the accuracy of the multi-Rayleigh model approximation. Finally, the ultrasound B-mode image in ROI was converted to the fibrotic probability image based on the multi-Rayleigh model.
Integrated simulation model for prediction of acoustic environment of launch vehicle
Authors: Park Seoryong , Yoon Kiseop , Ko Jeongwoo , Choung HanAhChim , Jang Seokjong , Lee Soogab
Published: November 2016

During a lift-off of a launch vehicle, a large amount of acoustic wave is generated by jet plumes. Acoustic waves lead to pressure fluctuations on the surface of the vehicle in the form of acoustic loads and these are transmitted to the internal payload. In order to evaluate the effects of acoustic loads, we developed the integrated simulation model. The model is mainly divided into two parts, prediction and reduction parts. First, the external acoustic loads are predicted empirically based on the Distributing Source Method-II (DSM-II) of NASA SP-8072. We developed the improved method able to consider the additional effects of surrounding structures. We perform a next prediction process for the internal acoustic environment by using Statistical Energy Analysis (SEA). For the Korean Sounding Rocket-III (KSR-III), we predict the internal acoustic environment and evaluate the stability of the payload in the fairing. After the prediction process, we perform the noise reduction simulation. With an active noise control (ANC) simulation, we could confirm the possibility and reliability of the noise reduction system.
Micro load theory of surface acoustic wave gravimetric sensors
Authors: Ge Li-Feng
Published: November 2016

Surface acoustic wave (SAW) gravimetric sensors have been widely applied in the field of chemical and biological detections for decades. However, it is noticed that the operating mechanism of this type of sensors is not understood well. A perturbation theory commonly adopted has been used to predict the mass sensitivity of the SAW sensors, but, as indicated also, “there is a significant and systematic quantitative discrepancy” between the theoretical and experimental results [Wohltjen, et al. IEEE UFFC, 1987]. In this paper, a micro load theory is presented. The coating film with biochemical material adsorbed is not regarded as a perturbation source, but a micro mechanical load. Then, it is revealed that the fractional frequency shift caused by the load is minus and half of the fractional area density change, where the unloaded area density is a product of the substrate material’s density and SAW wavelength. Also, it is interesting to note that the expression is the same with that for Lamb wave sensors if SAW wavelength is replaced by the plate thickness [Li-Feng Ge, POMA, ASA, 2009], which shows a general character of wave-based gravimetric sensors. [The work was supported by NSFC, Grant Nos. 60374044 and 60774053].
Development of a high presence virtual reality system by binaural sound field rendering with head mount display
Authors: Sugiura Kyosuke , Iino Shingo , Tsuchiya Takao
Published: November 2016

In this study, a high presence virtual reality (VR) system which integrates head mount display (HMD) and the binaural sound field rendering is developed. To realize a high presence VR system, it is necessary to provide interactive visual and sound environments in real-time. Recent VR systems can provide interactive visual environment by HMD; however, interactive sound environment is not enough, because enormous binaural room impulse responses (BRIRs) are required to obtain HRTFs at various room positions. So, we calculate BRIRs numerically using the CE-FDTD method with the GPU cluster system. For BRIR calculation, a room model including dummy-head scanned by 3D scanner is developed. In this system, it is possible to render binaural-sound interactively by convolving calculated BRIRs. The developed VR system consists of visual and sound part which is respectively processed by Unity and MAX. Position and head rotation of listener are obtained from tracking sensor by Unity, and the data are sent to MAX by OSC. MAX convolves calculated BRIRs changing by cross-fade. Listener can move their head in virtual room, and can feel sound field differences. It is confirmed that the system can produce the high presence virtual room.
Three-dimensional numerical simulation of parametric speaker by compact explicit finite-difference time-domain method
Authors: Tsuchiya Takao , Nomura Hideyuki
Published: November 2016

In this study, the three-dimensional numerical simulation of a parametric speaker is carried out. To simulate the secondary sound field of difference frequency generated by the high intense ultrasonic wave, the Westervelt equation is numerically solved by the compact explicit finite-difference time-domain (CE-FDTD) method which is a high-accuracy version of the standard FDTD method. In the simulation, the interpolated wideband (IWB) scheme that is one of the most accurate scheme of the CE-FDTD method and whose cut-off frequency is in agreement with the Nyquist frequency, is chosen to reduce computer resources. The IWB scheme is then implemented on a graphics processing cluster system. Three-dimensional numerical models whose size is 1.5 m x 1.5 m x 8 m are developed with cell sizes of 1 mm. Some demonstrations are made for the nonlinear sound wave propagation. The propagation characteristic and the directivity of the parametric speaker are obtained with reasonable accuracy.
Study of acoustic localization of an emergency siren
Authors: Angione Frank , Novak Colin , D'Angela Peter , Ule Helen
Published: November 2016

Having the ability to adequately detect the direction of an approaching emergency siren is critical to the effectiveness of the emergency system. Having this ability allows both pedestrians and drivers of nearby vehicles to more quickly and safely react to an approaching emergency vehicle. This study considers a typical electronic siren system that is currently being used by the Windsor Fire & Rescue Services Department. This siren has two fundamental settings: the standard siren signal and the air horn mode, which is typically used when the emergency vehicle is approaching roadway intersections, as these pose the most danger to occupants of both emergency vehicle and general public. Siren and air horn signals were recorded at specific distances from the driver’s position at 45° radial increments. From these, the recorded signals and sound pressure levels measured inside the cabin of the vehicle at the various approach angles were used to prepare a subjective jury evaluation to determine the localization characteristics under simulated roadway intersections conditions. Using the outcomes from this study, valuable knowledge was learned which can be applied to future improvements to enhance the localization characteristics of emergency siren systems.
Preparing and submitting manuscripts to the Journal of the Acoustical Society of America—Express Letters
Authors: Church Charles C.
Published: November 2016

The general process for preparing a manuscript for the Journal of the Acoustical Society of America—Express Letters (JASA-EL) is the same as for any other scientific publication. First, have something new and interesting to say to your colleagues. Second, say it clearly, without ambiguity, and with a minimum of unnecessary literary flourish. Finally, and most importantly for JASA-EL, be brief. Failure to follow any of these simple rules may produce lengthy delays in publication. In extreme cases, it may result in rejection of the manuscript even after the review process has been completed! Once a manuscript has been completed, it is very important to follow the formatting requirements for the journal, both for the length and the appearance of the text and tables of the manuscript itself but also for the file types accepted by our publisher, AIP (American Institute of Physics) Publishing. The submission procedure is relatively simple. For example, neither a cover letter nor a list of suggested reviewers is currently required (although this may change in the future!). However, there are a few characteristics of the process that authors should consider before beginning. These and other areas that are frequently sources of difficulty will be discussed.
Instructions for prospective authors to submit acceptable manuscripts to the Journal of the Acoustical Society of America
Authors: Xiang Ning
Published: November 2016

It is a common perception that the Journal of Acoustical Society of America (JASA) is considered as one of leading journals which has been serving the acoustics community for over 85 years. The JASA encourages authors to submit papers for JASA publication and at the same time practices a rigorous peer-review process to meet its aspirations for a higher degree of publishing excellence. For prospective authors a better understanding of JASA’s peer-review process is critically important. To increase the chance for submission acceptance, this talk will shed light to its peer-review process of the JASA, draw audience’s attention to some detailed, updated guidance and instructions regularly published by the JASA editorial board. As a frequent reviewer, an Associate Editor, and particularly a non-native author of the JASA papers, this author will share his own experience to analyze possible reasons for successful and unsuccessful publication effort using some disguised examples.
Best practices for publishing in scientific journals
Authors: Holland Christy K.
Published: November 2016

A string of impressive publications can be the lifeline for promotion and success for an academic. Once excellent data is produced from your innovative research program, how do you communicate the results as clearly as possible? As the editor in chief of Ultrasound in Medicine and Biology, I have witnessed first hand a range of successful strategies to get papers published. Making sure that your manuscript is aimed at the appropriate journal at the outset can save a great deal of effort and can get your work into print faster. Editors and Associate Editors seek advice from reviewers who are knowledgeable in the general subject of the paper, and the reviewers give opinions on various aspects of the work, including whether the work is original and correct. The editor and reviewers who examine each manuscript are the authors' peers: persons with comparable standing in the same research field as the authors themselves. The composition of a concise cover letter, the creation of an effective response to the reviewers’ critiques, and strategies for polite communication will be outlined and discussed. The good news is that editors want to publish your paper and appreciate individuals who create the scientific content that makes a journal thrive.
Simulation studies of the flute
Authors: Giordano Nicholas
Published: November 2016

Simulations of the transverse flute using direct numerical solutions of the Navier-Stokes equations are described. Constructing a numerical model of the instrument itself is straightforward, but making a semi-realistic model of the player's lips is more challenging. One solution to this problem is described and used to explore the kinds of tones that are possible. Conditions are found for which the model produces a well-behaved musical tone for a range of blowing speeds. When the blowing speed is increased beyond this range the behavior becomes complex and is appears to be chaotic. An analysis of this behavior in terms of the sensitivity to initial conditions and a route to chaos involving Hopf bifurcations is described. The relevance of these results to real instruments played by real players is also discussed. [Research supported by NSF grant PHY1513273.]
Localization in the piano soundboard
Authors: Lefebvre Gautier , Filoche Marcel , Boutillon Xavier
Published: November 2016

The soundboard is the complex plane structure that radiates the piano sound. We focus on its structural vibrations. The arrangement of the stiffeners (parallel bars) displays some disorder (height, separation distance) that has been shown responsible for the localization of the vibrations above a precise frequency (Ege 2013, JSV; Chaigne 2013, JASA) By means of a finite-element method, we investigate the localization properties of the eigenmodes of a simplified soundboard model. The localization occurs close to the band-edge of the first Brillouin zone, indicating the importance of a slightly disordered structure, similarly to photonic or phononic crystals with defects (John 1987, PRL). For structural parameters typical of a piano soundboard, this phenomenon seems to force the soundboard to remain in the subsonic regime in a very large frequency range. Moreover, by the adaptation of the theory of the localization landscape (Filoche 2012 PNAS), we compute a dual landscape (Lyra 2015 EPL) for the high-frequency modes of a stiffened orthotropic thin plate. This enables to predict the position of localized eigenmodes. [Work supported by the ANR grant ANR-14-CE07-0014.]
Real-time physical model of a grand piano soundboard on field programmable gate array hardware
Authors: Pfeifle Florian , Bader Rolf
Published: November 2016

A modern grand piano consists of over 10,000 singular parts and has a production cycle of approximately one year. This leads to the predicament that researching and changing acoustical features resulting from variable material properties of the instrument cannot be realized in a straightforward manner. The inevitable time delay as well as the variability of parameters makes a controlled research very hard, if not impossible. In this work, a system is presented that enables piano makers to change, simulate as well as auralise acoustical vibrations of a grand piano soundboard in real time using physical modelling methods on field programmable gate array (FPGA) hardware. This specific implementation focusses on synthesizing and simulating the vibrations of a geometrically complete model of a concert grand piano soundboard, including the ribs, the bass, and main bridge, realistic material parameters as well as coupled strings. It can be parametrized and controlled from a software GUI running on a personal computer. This implementation is part of a larger project aiming at modeling a complete grand piano in real-time for research, instrument making as well as purely musical applications.
Evaluating aircraft ground operation noise in airport noise modeling and monitoring in Japan
Authors: Yamada Ichiro
Published: November 2016

The current Japanese noise guideline “Environment Quality Standard for Aircraft Noise” requires considering noise of aircraft ground operation, which we call ground noise here, like APU operation, taxiing, and engine run-up, if necessary. It has inevitably required us not only to take account of ground noise contributions in the Japanese airport noise model JCAB2, but also to include techniques to identify or discriminate ground noise from the ambient noise floor when fulfilling airport noise monitoring. Ground noise sometimes lasts very long and is usually low level compared with flyover noise. First, this paper makes a brief review of the way to evaluate ground noise in airport noise modeling and monitoring in Japan. Second, it discusses further issues to improve the reliability in the evaluation of ground noise under the influences of excess ground attenuation, meteorological condition, sound shielding by obstructions like building structures and embankment, as well as contamination by noise events.
An aircraft noise prediction model considering meteorological effects on noise propagation developed for air traffic optimization
Authors: Ishii Hirokazu , Andreeva-Mori Adriana , Yokota Takatoshi , Makino Koichi , Matsumoto Toshio
Published: November 2016

With the growing transportation demand, the volume of air traffic is already approaching and will soon exceed the capacity limit posed by current air traffic control. Japan Aerospace Exploration Agency (JAXA) has conducted a research project called DREAMS, aiming to develop technologies for future air traffic management system. One of the research topics examined by the project is noise abatement flight technology. It optimizes approach paths considering the meteorological effects on noise propagation. Its key element is an aircraft noise prediction model which can take into account the effect of meteorological conditions on noise propagation. The effect is computed by Green’s Function-Parabolic Equation method and verified by field experiment using an elevated sound source. Aircraft noise is measured around approach flight path for overall verification, and the results show the average and the standard deviations of the prediction error are -0.66 dB and 1.55 dB, respectively. The presentation provides an overview of the development and the verification of the noise prediction model, followed by a comparison between noise footprints calculated with JAXA’s model and the Integrated Noise Model (INM). Application of the noise prediction model to descent flight path optimizations for noise abatement is also shown.
Robustness of the extended delayed-X harmonics synthesizer algorithm applied to engine exhaust noise control
Authors: Jukkert Sergej , Sachau Delf
Published: November 2016

Exhaust noise of a combustion engine contains several harmonic components of the fundamental frequency that depends on the engine speed. Active noise cancellation (ANC) in the exhaust line of a diesel-electric drive faces serious challenges such as high temperature, high sound pressure levels, standing waves phenomena, a time-varying environment, and slightly varying disturbance frequencies. In the case of a non-acoustic reference sensor, also an offset or a mismatch in the estimation of the disturbance frequencies negatively affects the performance. The extended delayed-X harmonics synthesizer (DXHS) is known from several researches to be appropriate for control of periodic noise with multiple harmonic components. The algorithm is robust against observation noise and fluctuation of the plant under control. In this paper, the extended DXHS is implemented in an ANC-system for a diesel-electric drive and experimentally investigated in laboratory experiments. A modified update rule, a convergence factor regulation, and the pre-filtering of the error signal are implemented to improve the DXHS. Performance and robustness are tested in a mockup of an exhaust line in which realistic fluctuations of temperature and gas flow as well as varying frequencies and amplitudes of the exhaust noise are simulated.
A second-order, perfectly matched layer formulation to model 3D transient wave propagation in anisotropic elastic media
Authors: Assi Hisham , Cobbold Richard S.
Published: November 2016

Perfectly matched layers (PML) are a well-developed method for simulating wave propagation in unbounded media enabling the use of a reduced computational domain without having to worry about spurious boundary reflections. Using this approach, a compact three-dimensional (3D) formulation is proposed for time-domain modeling of elastic wave propagation in an unbounded general anisotropic medium. The formulation is based on a second-order approach that has the advantages of well-posedness, physical relationship to the underlying equations, and amenability to be implemented in common numerical schemes. However, many auxiliary variables are usually need to described second-order PML formulations. The problem becomes more complex for the 3D case modeling which would explain the dearth of compact second-order formulations in 3D. Using finite element method (FEM), 3D numerical results are presented to demonstrate the applicability of our formulation, including a highly anisotropic medium example. Extension of the PML formulation to model the case of a Kelvin-Voigt viscoelastic medium is also provided. In addition, we will present the extension of this formulation to model the transient wave propagation in an unbounded fluid-solid 3D medium in a similar way to that presented by the authors (JASA, 2016) for the 2D case.
Backward masking abilities for speech and tones in persons who stutter
Authors: Basu Shriya , Schlauch Robert S. , Sasisekaran Jayanthi
Published: November 2016

We examined eight persons who stutter (PWS) and eight carefully matched adult, control participants for their ability to identify vowel-consonant (VC) syllables and to detect tones in a backward masking paradigm. Speech scores (percent correct) were obtained in quiet and in conditions with a fixed-level broadband masker with a delay of 0 ms and 300 ms. Tonal thresholds (1000 Hz) were obtained using an adaptive procedure in quiet and with the same masker delays as in the speech conditions. The results revealed significantly poorer performance for PWS for all of the speech conditions, including the quiet condition. Tonal thresholds in quiet and for the condition with a 300 ms delay were identical for the two groups, but, on average, the trend was for higher masked thresholds for PWS than for the control group in the 0 ms condition. The poorer speech results are consistent with the idea that PWS may have less distinct representations of phonemic categories that are revealed in a VC task that lacks a language context.
Why does gap detection performance in cochlear implant users differs between free-field and direct-stimulation?
Authors: Gaudrain Etienne , Bhargava Pranesh , Başkent Deniz
Published: November 2016

Gap detection (GD) is used to measure temporal resolution in the auditory system. Previous studies have shown that GD performance in cochlear implant (CI) users is similar to, or sometimes better than, that observed in normal hearing (NH) listeners when simple stimuli are used (e.g., tones, noise). In a recent study employing more ecological speech stimuli, we observed that CI listeners only performed comparably to NH listeners when bypassing the clinical processor and stimulating the implant directly from a research interface. When the stimuli were presented in free field, i.e., through the participants’ clinical processor, their GD performance was markedly worse than that of NH listeners. To determine the origin of the discrepancy between direct stimulation and clinical processor results on GD, in the present study, we compared the electrodograms delivered by the implant in the direct stimulation condition to those delivered by the clinical processors of the participants. Our results show that certain aspects of the processing in the implant, likely related to automatic gain control, do reduce the depth of the gap, which is consistent with a reduction in gap detectability. We suggest that GD with natural stimuli could be used to better tune the implant.
Context effects in pitch discrimination
Authors: Arzounian Dorothée , de Cheveigné Alain
Published: November 2016

The perceived direction of pitch change between a pair of tones depends on their frequencies, but may also depend on the prior history of stimulation or behavioral response. To quantify the contribution of such context effects, we used a recently developed pitch change discrimination paradigm in which subjects judge the direction of change after each tone of a continuous sequence of tones. Responses were determined primarily by the frequency change of the last pair of tones, but could also be significantly influenced by the frequency of the tone preceding the pair, as well as by the latest response. The magnitude and sign of the effects were subject-dependent, some subjects showing no measurable effect, while in others the weight of the previous stimulus in the decision can go up to half of the weight of the ongoing stimulus. Taking into account these contributions allows for a better estimation of the slope of the psychometric function relating response to frequency change, and thus a better estimate of sensory sensitivity.