bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of prior intense noise exposure on the ability of big brown bats to navigate through clutter
Authors: Hom Kelsey N. , Simmons James A. , Simmons Andrea
Published: June 2017

Big brown bats (Eptesicus fuscus) emit intense biosonar calls and process returning echoes to forage and guide flight. Sound pressure levels of emissions can exceed 110-120 dB SPL, amplitudes known to produce temporary threshold shifts in other vertebrates. We conducted behavioral experiments to test the limits of bats’ ability to navigate after intense noise exposures. Bats were trained to fly through a dense array of chains that produce a pattern of echoes mimicking those they would receive when flying along vegetation. We quantified flight accuracy (10 flights) and changes in the number and temporal patterning of emissions before and after exposure to intense broadband noise (1 hr, 116 dB SPL). Four bats tested 20 min post-exposure maintained flight accuracy and did not alter the temporal patterning of emissions from that observed pre-exposure. In contrast, two of three bats tested 2 min post-exposure initially would not perform the task or made errors in navigation. Temporal patterning of emissions during successful flights did not vary significantly from those measured during pre-exposure flights. These data suggest that prior intense noise exposure affects motivation to fly but not the ability to process returning echoes. [Work supported by ONR and the Capita Foundation.]
Vocalizing strategies for acoustically jammed conditions for bat echolocation
Authors: Riquimaroux Hiroshi
Published: June 2017

Extraction of signal from noise is quite difficult when both signal and noise have the same temporal and spectral characteristics, for example, extraction of speech sounds of a single speaker from background of speech sounds from group of people. However, we can extract speech signal of a particular person from a group of speech noise, called cocktail party effects. Echolocating bats often come across similar situation where their own vocal signals are masked by vocalizations emitted by neighboring bats. Flying horseshoe bats, Rhinolophus ferrumequinum, would compensate Doppler-shifted returning echo frequencies to be constant by adjusting frequency of emitted pulses, called Doppler-shift compensation. Amplitudes of the second harmonic are the most intense in echo locating sounds. Once emitted pulses and returning echoes are added, a powerful masker is created. During acoustically jammed conditions, paradoxically bats tend to make their echo reference frequencies even closer. How can they still conduct Doppler-shift compensation? They would amplify the fundamental frequency of FM component. How can they make the fundamental frequency, not the second harmonic, the strongest? The reason why and how they conduct this behavior will be discussed. [Work supported by MEXT Japan and Grant from Shandong University.]
Neural spike train similarity algorithm detects differences in temporal patterning of bat echolocation call sequences
Authors: Accomando Alyssa W. , Vargas-Irwin Carlos , Simmons James A.
Published: June 2017

Bats emit echolocation sounds in complex temporal sequences that change to accommodate dynamic surroundings. Efforts to quantify how these patterns change have included analysis of inter-pulse intervals, sonar sound groups, and changes in individual signal parameters. No standardized method has been adopted for quantifying whether sequences of echolocation calls are similar or different beyond these individual dimensions. Here, a new method is presented for assessing the similarity in temporal structure between trains of bat echolocation sounds. The spike-train similarity space (SSIMS) algorithm, originally designed for neural data analysis, was applied to determine which features of the environment influence temporal patterning of echolocation sounds emitted by flying big brown bats (Eptesicus fuscus). Using a relational point-process framework, SSIMS was able to discriminate between pulse sequences recorded in different flight environments, as well as to separate flights depending on the bat’s expectation of its surroundings based on previous experience.
Why hipposiderid biosonar is worth studying
Authors: Müller Rolf , Zhang Ru , Zhang Liujun , Qiu Peiwen , Yin Xiaoyan
Published: June 2017

Although the genus Hipposideros contains a diverse set of more than 70 species of echolocating bats, the biosonar system of this group has received far less attention than that of the related horseshoe bats (family Rhinolophidae) which share the same basic cf-fm biosonar. Only a relatively small number of field observations can be found in the literature and even fewer laboratory studies on hipposiderids have been reported. The Shandong University—Virginia Tech International Laboratory has been working with two of the larger hipposiderid species, the great roundleaf bat (Hipposideros armiger) and Pratt's roundleaf bat (Hipposideros pratti) and has conducted biosonar as well as flight experiments with individuals from both species. It was observed that the bats from both species have highly dynamic biosonar systems that employ large non-rigid noseleaf motions as well as large rigid and non-rigid motions of the pinnae. The motions seen in the hipposiderids appear to be relatively larger and more frequent than those in the greater horseshoe bats with which similar experiments were conducted. In addition, the hipposiderids bats tested were found to be maneuverable fliers that should make an excellent model system for the integration of dynamic sonar with a highly capable flight system.
The relationship between pinna and noseleaf motions in hipposiderid bats
Authors: Zhang Shuxin , Zhang Liujun , Zhang Ru , Müller Rolf
Published: June 2017

Old World leaf-nosed bats (Hipposideridae) are a family of bat species that use elaborate baffle shapes to diffract the outgoing ultrasonic pulses and the returning echoes. The baffles at both interfaces (“noseleaves” for emission, outer ears for reception) have dynamic geometries that can be changed through muscular actuation. Shape changes in noseleaves and pinnae can both coincide with sound emission and reception respectively, but the relationship between the dynamics in these two structures has yet to be investigated. To study this relationship, a set of no less than 17 landmarks was placed on the noseleaf and one ear of Pratt's roundleaf bats (Hipposideros pratti) to track the dynamic geometry of these structures simultaneously with a high-speed video camera array. The three-dimensional trajectories of the landmark points were reconstructed using stereovision. The results showed strong, systematic relationships between noseleaf and pinna motions that were found to belong to two different qualitative types. In the first type, noseleaf motions and pinna motion did not change direction during the recording period (e.g., one pulse) which resulted in approximately linear relationships between the positions of the landmarks on both structures. In the second type, direction reversals occurred, but coupling between the motions remained evident.
A simulation study of the biosonar information in natural foliage echoes
Authors: Ming Chen , Zhu Hongxiao , Müller Rolf
Published: June 2017

Echolocating bats are capable of accurate navigation in forests at night. To understand how they perceive the vegetation echoes and find passage ways in dense foliage, previous work by the authors has studied a model for homogeneous foliages that distributed leaves uniformly in a domain, simplified individual leaves as circular disks and hence described an entire foliage by only three parameters (mean leaf radius, orientation, and density). To further explore which additional information inhomogeneous structures within a foliage may impart on the echoes, the model was transitioned from uniform leaf distributions to digital trees with branches and leaf clusters using L-systems to mimic the branching patterns of natural trees. When the tree size was small with very few and short child branches, inhomogeneities in the echoes were readily apparent no matter how wide the beam was. If the tree crown was large, featuring many branches and leaf clusters, the amount of inhomogeneity seen in the echoes depended on the relative scale between the tree size and sonar beamwidth. When big trees and relatively narrow sonar beamwidths were paired in the simulation, the echoes were inhomogeneous; as the beam got wider, the generated echoes were getting more homogeneous.
Dolphin auditory brainstem responses to frequency-modulated “chirps.”
Authors: Finneran James J. , Mulsow Jason , Jones Ryan , Houser Dorian S. , Burkard Robert F.
Published: June 2017

Previous studies have demonstrated that increasing-frequency chirp (up-chirp) stimuli can enhance auditory brainstem response (ABR) amplitudes by compensating for temporal dispersion occurring along the cochlear partition. In this study, ABRs were measured in two bottlenose dolphins in response to 5-µs, spectrally “white” clicks, up-chirps, and decreasing-frequency chirps (down-chirps). For all stimuli, bandwidth was constant (10 to 180 kHz) and peak-equivalent sound pressure levels (peSPLs) were 115, 125, or 135 dB re 1 μPa. Chirp durations varied from 125 to 2000 μs. Up-chirps with durations less than ~1000 μs generally increased ABR peak amplitudes compared to clicks with the same peSPL or energy flux spectral density level, while down-chirps with durations above ~250 to 500 μs decreased ABR amplitudes relative to clicks. Increases in ABR amplitude occurred with up-chirps having a broad range of durations. The findings parallel those from human studies and suggest that the use of chirp stimuli may be an effective way to enhance broadband ABR amplitudes in larger marine mammals. [Work supported by US Navy Living Marine Resources Program.]
Dolphin click-evoked auditory brainstem responses obtained using randomized stimulation and averaging
Authors: Finneran James J.
Published: June 2017

Measurement of auditory brainstem responses (ABRs) using conventional averaging (i.e., constant interstimulus interval, ISI) is limited to stimulus rates low enough to prevent overlapping of the ABRs to successive stimuli. To overcome this limitation, stimuli may be presented at high rates using pseudorandom sequences (e.g., maximum length sequences) or quasi-periodic sequences. However, these methods restrict the available stimulus sequences and require deconvolution to recover the ABR from the overlapping responses. Randomized stimulation and averaging (RSA) is an alternate method for measuring evoked responses at high stimulus rates that allows more control over stimulus jitter, is flexible with respect to sequence parameters, and does not require deconvolution to extract the ABR waveform [Valderrama et al. (2012). “Recording of auditory brainstem response at high stimulation rates using randomized stimulation and averaging,” J. Acoust. Soc. Am. 132, 3856-3865]. In the RSA method, ABRs are obtained by averaging responses to stimuli with ISIs drawn from a random distribution. In this study, ABRs were measured in three dolphins using conventional averaging and RSA. Results show the RSA method to be effective provided the ISI jitter exceeds ~1-2 ms. [Work supported by the Naval Innovative Science and Engineering (NISE) Program at SSC Pacific.]
The dynamics of a dolphin’s biosonar signals while performing target discrimination tasks
Authors: Au Whitlow , Atkins John , Harley Heidi E. , Volpilier Henri , Fellner Wendi
Published: June 2017

An experiment was conducted to determine if a blindfolded echolocating dolphin modified its biosonar signals depending on the targets it was investigating in a target shape discrimination task. Biosonar signals were measured with a specially designed bite-plate apparatus with a dowel extending from the bite plate to support the hydrophone. The detected signals were digitized and stored on a modified SoundTrap (Ocean Instrument New Zealand) attached to the dowel. The dolphin engaged in a matching-to-sample task: he first examined a sample target and then swam to a different area of the pool to examine three alternative targets, one of which matched the sample. The animal’s task was to point to the matched target. The characteristic of each emitted signal was determined by calculating the peak frequency, center frequency, rms bandwidth, and rms duration. A specific target set was used for each session of 15-18 trials; some sets were unfamiliar to the dolphin. Considerable amount of variations in the signal parameters were observed across trials and sessions, but our statistical analyses suggested the variations were not based on target identity, thereby leading us to conclude that the clicks emitted by the dolphin did not differ with the target set.
Separation of MiPS/MaPS spectrogram transformations in biosonar
Authors: Shriram Uday , Simmons James A. , Zorikov Tengiz
Published: June 2017

Echolocating bats and dolphins differ in signals, sound emission, and reception pathways, and important aspects of the acoustic medium. They do, however, receive broadcasts and echoes through similar parallel bandpass filters in the cochlea, which impose integration-times of several hundred microseconds. Echoes consisting of several overlapping reflections from target glints (insect body-parts, fish swim bladders) interfere upon reception to form complex echoes with spectral interference patterns that characterize the target’s shape. Bats transform these patterns into images that depict the glints themselves along the range axis, a process called Spectrogram Correlation and Transformation (SCAT). Experiments with dolphins suggest two different scales for recognizing shape from echo spectra—macro- vs micro-power spectral features for ST (MaPS for short glint separations of <80 µs; MiPS for longer separations >80 µs). We tested this finding in big brown bats trained to distinguish between 2-glint echoes with long, MiPS-like and short MaPS-like spectral features and found that MiPS covers delay separations of about 25-500 µs from the frequency separation of spectral nulls, which have to fit into FM1 for ST to occur. At a deep level, dolphins and bats appear to share a common processing strategy for forming images. [Work supported by ONR.]
Sediment parameter inversions in the East China Sea
Authors: Potty Gopu R. , Miller James H , Dosso Stan E. , Bonnel Julien , Dettmer Jan , Isakson Marcia J.
Published: June 2017

Geoacoustic inversions using wide-band acoustic sources (WBS) deployed during the Asian Seas International Acoustic Experiment (ASIAEX) along a circular path of radius 30 km centered on a vertical hydrophone array was used to construct a pseudo 3D model of the seabed sediments [Potty et al., J. Acoust. Soc. Am. 140, 3065, 2016]. The geoacoustic inversion approach is based on trans-dimensional Bayesian methodology in which the number of sediment layers is included as unknown in addition to the layer parameters. In this study, the inverse problem is recast such that the unknown parameters are sediment parameters such as porosity, permeability, grain size, etc. The compressional and shear wave speeds and attenuation are estimated from these parameters using Biot or similar geoacoustic models. This inversion approach enables direct comparison of the inversion results to ground truth measurements for sediment cores. High resolution time-frequency analysis techniques were applied to extract modal arrival times accurately. One-dimensional (depth-dependent) inversions will be applied along the various acoustic propagation paths to construct a pseudo 3D sediment model using interpolation. [Work supported by the Office of Naval research.]
Towards transcranial focused ultrasound treatment planning: A technique for reduction of outer skull and skull base heating in transcranial focused ultrasound
Authors: Hughes Alec , Huang Yuexi , Hynynen Kullervo
Published: June 2017

Transcranial focused ultrasound is a rapidly-growing therapeutic modality with expanding applications in the treatment of brain disorders and diseases. As more treatments are proposed by clinicians, the need for comprehensive, accurate treatment planning is required to take into account the complexities that can arise from the application of ultrasound to the brain. These include skull heating, both on the outer surface of the skull and at any bone at the skull base, as well as phasing corrections for skull aberration corrections. We will present a method for the reduction of outer skull and skull base heating by using phased array controls. First, full-wave numerical simulations are used to demonstrate the corrections on a clinically relevant skull base target using exported clinical imaging data. Then, results from ex vivo experiments are presented to illustrate the application of these phased array controls in the reduction of skull heating by scanning a 3D volume of heating around the focus, while computing the corrections in a clinically relevant timescale. Potential limitations of the method and future directions will also be discussed.
Passive localization and classification of cavitation activity using group sparsity
Authors: TOP Can Baris , Gungor Alper , Guven H. Emre
Published: June 2017

In therapeutic high intensity focused ultrasound (HIFU) applications, cavitation mapping is a powerful tool to monitor and guide the treatment procedure. Furthermore, the frequency spectrum of the cavitation activity can be used to classify the mode of cavitation (stable/inertial), enabling a means for increasing the safety of the application. In this study, we formulate the cavitation mapping as a group sparse constrained optimization problem, minimizing l2,1-norm of the solution. The frequency bins related to a class of cavitation activity (harmonic, ultra-harmonic, or broadband) are grouped using l2-norm for each voxel, and l1-norm of the image is minimized. We solve this problem using an Augmented Lagrangian Method, specifically the Alternating Direction Method of Multipliers (ADMM). We used a simulation model to test this method on a 300 mm diameter 128-element hemispherical receiver array application. We calculate the radiated pressure from the microbubbles inside the HIFU beam using a rigid vessel bubble dynamics model. Then, we reconstruct the image associated with the bubble activity at the focal region using the received signals for various focal pressure distribution scenarios. The results show that the proposed method provide improved resolution and sensitivity, especially for localizing inertial cavitation activity.
Cavitation enhanced drug delivery
in-vivo
using combined B-mode guidance and real-time passive acoustic mapping: Challenges and results
Authors: Coviello Christian , Myers Rachel , Jackson Edward , Lyka Erasmia , Morris Lauren , Rowe Cliff , Kwan James J. , Carlisle Robert , Coussios Constantin
Published: June 2017

Inertial cavitation nucleated by nano-scale sonosensitive particles (SSPs) at modest peak negative pressures (~1 MPa at 500 kHz) and monitored by passive acoustic mapping (PAM) has been recently shown to improve the dose and distribution of anti-cancer agents during ultrasound (US) enhanced delivery (Myers 2016, Kwan 2015). As applications of therapy monitoring using PAM have advanced rapidly including its use in clinical trials, means of validating the performance of PAM in-vivo remains a major focus of efforts. For drug delivery, PAM should not only quickly and reliably detect and localize desired and undesired cavitation, but it should provide some predictor of successful delivery. In-vivo experiments using PAM in subcutaneous tumor implanted murine models across a range of cancer cell lines (HEPG2, SKOV, EMT6, CT-26) demonstrate the detection of inertial cavitation by SSPs in the target regions when sonicated by US, but no cavitation with US alone. Additionally when SSPs are co-administered with an oncolytic virus (vaccinia), a small molecule chemotherapeutic (doxorubicin), or an immunotherapeutic (anti-PD-L1 antibody), PAM is able to effectively predict successful delivery in the presence of cavitation in the target regions and unsuccessful delivery in the absence of cavitation in target regions. Enhancements to PAM to deal with artifacts, spurious reflections, and to increase resolution were also able to improve the monitoring capability. Future work focuses on clinical translation and improved validation methods.
Passive microbubble imaging with short pulses of focused ultrasound and absolute time-of-flight information
Authors: Burgess Mark T. , Apostolakis Iason , Konofagou Elisa
Published: June 2017

Focused ultrasound (FUS)-stimulated microbubble activity has been proposed as an efficient technique in numerous therapeutic ultrasound applications. Passive imaging of microbubble activity is used to spatially map the intensity and location of microbubble activity for correlation with therapeutic outcomes. Current passive imaging methods were developed for application with continuous-wave FUS therapies and have inherent limitations including poor axial image resolution. This study seeks to implement a synchronous passive microbubble imaging method using short pulses of FUS (200-500 kPa peak negative pressures, 2-3 cycles) at high frame rates (500-5000 Hz pulse repetition rate) to preserve absolute time-of-flight and improve axial resolution. In vitro and in vivo studies were carried out using an 18-MHz imaging array (L22-14v LF, Verasonics, Inc.) and 1-MHz FUS transducer aligned off-axis relative to the imaging array. A research-based ultrasound system (Vantage 256, Verasonics, Inc.) was used for custom transmit and receive sequences. Results indicate that this technique is able to “localize” microbubbles with improved resolution compared to previous methods and create detailed microvascular maps of microbubble activity throughout the focal area. The application of this technique for monitoring FUS-mediated blood-brain barrier opening will be shown. [Work supported in part by NIH grants R01AG038961 and R01EB009041.]
Ex vivo testing of basal cell carcinomas and melanomas with high-frequency ultrasound
Authors: Dalton Christine E. , Coffman Zachary A. , Wagner Garrett , Doyle Timothy E.
Published: June 2017

The objective of this study is to significantly reduce the length of surgery for skin cancer patients by developing a diagnostic method to quickly distinguish cancerous from non-cancerous tissue. A common treatment for basal cell carcinoma and several melanomas is Mohs surgery, consisting of surgical resection of the tumor and successive resections of the surrounding tissues (margins). Because each excised specimen needs to be examined for cancerous margins, skin cancer surgery can last up to 4 hours. To rapidly evaluate Mohs surgical specimens, a high-frequency (20-80 MHz) ultrasound method, originally developed for testing breast cancer surgical specimens, was modified for smaller skin cancer tissues. The method uses a narrow-beam (1.5-mm diameter) probe, a broad-beam (6.35-mm diameter) transducer, an ultrasonic pulser-receiver, a digital oscilloscope, an aluminum test stage to hold the specimen, and a hybrid water immersion/contact approach to acquire highly accurate data. The method is currently undergoing a feasibility study on skin cancer surgical margins at the Huntsman Cancer Institute, Salt Lake City, Utah. Preliminary results from 16 patients show that the 20-80 MHz peak density values from the power spectra are consistent with those found in previous breast cancer margin studies.
Ultrasonic characterization of human colon carcinoma cells in the 5-25 MHz frequency range
Authors: Longstreth Amy , Thomas Judene , Kwakwa Yaa , Davis Janae , Herd Maria-Teresa
Published: June 2017

Early recognition of cancerous tissue is crucial in receiving a favorable prognosis. Diagnostic tools that allow for an understanding of differences in the ultrasonic characteristics (such as speed of sound (SOS), attenuation, and backscatter coefficients (BSC)) in malignant and benign cells can aid in early diagnostics. Although statistically significant distinctions between benign and cancerous tumor scatterer properties have been demonstrated, there is little knowledge about which cell characteristics create differences in scattering. This study centers on techniques using quantitative ultrasound to quantify the microstructure of HTC (colon cancer) cells in an attempt to establish a greater understanding of scattering mechanisms. To analyze these characteristics HTC cells were cultured, suspended in agar and prepared into samples. Broadband BSC measurements were conducted using focused transducers and narrowband attenuation and SOS measurements were performed using receiving and transmitting transducers. All experiments were made in the 5-25 MHz range at 21°C. A comparison of the obtained results was made with a similar study using a higher concentration of HTC cells to test the ability to accurately estimate the ultrasonic properties. The results introduce relevant data useful for comparative studies and further analysis.
Numerical investigation of the subharmonic response of a cloud of interacting microbubbles
Authors: Haghi Hossein , Jafari Sojahrood Amin , Karshafian Raffi , Kolios Michael C.
Published: June 2017

Microbubbles (MBs) usually exist in polydisperse populations and often strongly interact with each other. Accurate investigation of the dynamics of the MBs requires considering the interaction between Microbubbles. We have developed an efficient method for numerically simulating N interacting MBs. The subharmonic (SH) responses of a polydispersions of 3-52 microbubbles with sizes between 2-5 microns, excited with ultrasound with a frequency and pressure of 1.8-8 MHz and 1-500 kPa were investigated. We show that if the frequency is set to the SH resonance of the larger MBs, the smaller MBs oscillations are controlled by the larger MB and the SH amplitude of the population of MBs increases. For small enough distances between MBs, one large MB may control the oscillations of the rest. If the excitation frequency is equal to the SH resonance of the smaller MBs, there exists two pressure regions. For lower pressures, the oscillations of the larger MB are out of phase with the smaller MBs and the resulting SH amplitude is smaller than the case without the bigger MB. As the pressure increases the oscillations of the larger MB becomes in phase with the smaller MBs and the SH response of the system is enhanced.
Reduced-size backing electrode microphone: Models and measurements
Authors: Qian Cheng , Podkovskiy Alexey , Honzik Petr , Joly Nicolas , Durand Stephane
Published: June 2017

Reduced-size backing electrode microphones have been developed recently to achieve an easier match to specified response requirements. Such a development has used both analytical and numerical multi-physics modelings to validate the architecture efficiency. This microphone is composed of a membrane covering an annular cavity surrounding a central backing electrode. This simplified structure leads however to a higher sensitivity and an larger bandwidth, as shown in previous publications. A new modeling, based on lumped elements modeling, has been developed, in order to provide an easy a quick design tool for choosing the microphone parameters, these ones being fitted more precisely with a FEM modeling. These tools have leaded to the development of prototypes which have been characterized. The comparison of the measured data to the ones computed with the different models is presented. It shows a pretty good agreement between the several modelings and the experimental data, and it enlightens the need to take into account parasitic capacitance effects.
Efficiency of capacitive micromachined ultrasound transducers For large signal non-collapsed operation
Authors: Pirouz Amirabbas , Degertekin F. Levent
Published: June 2017

Although capacitive micromachined ultrasonic transducers (CMUTs) are mostly considered for imaging applications for their broad bandwidth, these devices can also prove useful for high intensity focused ultrasound (HIFU) applications for therapeutics. For these purposes, energy conversion efficiency is especially significant for high intensity and high duty cycle ultrasound applications. The usual small signal coupling coefficient analysis based on capacitance and resonance frequency measurement is not adequate for large signal application when nonlinearity comes to affect device performance. Therefore, an energy conversion ratio (ECR) based on a nonlinear large signal model has been proposed to analyze high power CMUT operation with and without DC bias (AC only). The results on a particular CMUT operating around 5 MHz show that AC only operation at half of device working frequency provides a higher level of pressure (0.8 dB more) as compared to DC biased case and can achieve 90% ECR. Since the input and output frequencies are not the same for AC only operation, Insertion loss (IL) is defined as the ratio of mechanical output power divided by the available electrical power in this case. With that definition, AC only and DC biased operation shows about the same IL in line with the ECR calculations.
Active control of a finite line source using multiple directional sources
Authors: Hu Qi , Tang Shiu-Keung
Published: June 2017

The active control of a finite line source in free space is studied using different types of secondary control sources to create a particular quiet zone. The simulations based on analytical formulation indicate that the active control improves significantly with the usage of directional secondary sources, such as axially oscillating baffled circular pistons. The comparison between directional sources of different directivity patterns shows that the directivity property has a determinant effect on the control results. A multi-part directional source, then, is introduced as the novel secondary control sources with its simplest two-part type. It consists of an inner-piston and an outer-concentric-annulus both oscillating axially with optimized amplitudes and relative phase. This novel secondary source helps to achieve excellent control results within a realistic physical size. The control performance regarding the novel sources with more outer annuluses are also studied.
Influence of piezoelectric materials on the performance of thin film hydrophones
Authors: Lewitz Hanna , Quandt Eckhard
Published: June 2017

Piezoelectric materials have been implemented in hydrophones in the early 20th century, mostly as cut bulk sensors or in cylindrical or spherical form made of piezoelectric materials [1]. Beginning with quartz soon other materials have been used, especially lead zirconate titanate with its high piezoelectric coefficients has been a large improvement in acoustic measurements. Nowadays miniaturization of the hydrophones is of interest, for example, in high resolution arrays for noise monitoring. Thus hydrophones materials are needed which have with less volume a similar performance as the state of the art bulk materials. Therefore, this work investigates hydrophones based on different piezoelectric thin films. These are mostly MEMS-production compatible and show good properties for the detection of acoustic signals. Therefore, sensors with different materials have been produced and the performance has been evaluated under laboratory conditions. [1] C. H. Sherman, J. L. Butler, Transducers and Arrays for Underwater Sound, Spring Sciences + Business Media, New York, 2007.
Hybrid shaping applied to concert hall design
Authors: Nepomuceno José A. , Blair Christopher
Published: June 2017

One of the first questions posed at the beginning of any concert hall design process is whether the room will be in the traditional long “shoebox” shape or the more intimate wrapping of the audience around the performers, characteristic of the “vineyard” approach. This paper presents the design process, acoustical measurements, and musician comments for a recently completed room where the answer was “both”. Sala Minas is the home of the Orquestra Filarmônica de Minas Gerais, Belo Horizonte, Brazil. The concert hall has 1500 seats with a hybrid shape combining the attractive physical and acoustical attributes of shoebox and vineyard approaches. While the audience is held close to the performers, enhancing clarity and impact, the basic room geometry is a modified rectangle with a significant vertical “hard cap” zone providing ample reverberation, envelopment, and blending of orchestral sections. The result is a vineyard configuration with unusually consistent acoustic character in all the seating sections. Adjustable acoustic elements include a movable canopy over the stage, motorized acoustical banners, and shutters on the stage walls that can be opened or closed. After two seasons since Sala Minas opening, the reviews about its acoustics are impressive.
V.L. Jordan and Jørn Utzon: Acoustic and architectural interactions in the early design of the Major Hall at the Sydney Opera House, 1957-1962
Authors: Clements Pamela
Published: June 2017

Vilhelm Lassen Jordan was the first acoustician engaged by Jørn Utzon to work on the Sydney Opera House. Jordan was a Danish acoustic engineer whose advice was based in strictly scientific, quantifiable acoustics, combined with precedent. He was a pioneer in acoustic modeling. Jordan had a major influence on Utzon’s first scheme for the Major Hall—a “rectangular “ form showing Jordan’s classic approach to acoustic design. Utzon’s second, “faceted” scheme, developed between August 1960 and September 1963, was architecturally compelling but showed little of Jordan’s influence. Jordan complained of the architect’s “fancies” in the design, and by 1962 Utzon believed that Jordan had “given up.” In June 1962, Utzon brought in Lothar Cremer and Werner Gabler from the Berlin Institute for Technical Acoustics, acousticians who provided scientific acoustic expertise and also worked with Utzon to integrate their acoustic recommendations into his design. This paper focuses on Jordan’s early acoustic input into the design of the Major Hall, including his collaboration with Utzon on the first (rectangular) scheme and his early design of the second (faceted) scheme. It also considers dichotomies between science and art in the early design approaches of Jordan, Cremer and Gabler for the Major Hall.
Auditory perception in rooms
Authors: Blauert Jens , Braasch Jonas
Published: June 2017

In the design process of concerts halls, it is the task of the architects—preferably with the aid of experience acoustical consultants— to transform their concept on how the hall should sound into built form. To this end, a profound knowledge of the psychoacoustics of listening in concert halls is mandatory. Psychoacoustics relates auditory perception to the physical attribute of the sound field in the hall. While the sound field can be assessed by physical measurement, the measurement of auditory percept requires human assessors. However, to avoid costly listening test, algorithms been developed for estimating certain features of auditory percepts in concert halls. These estimators are useful for computer simulations of halls. In our talk, basic psychoacoustic phenomena and relevant instrumental estimators for psychoacoustic features will be evaluated. Finally, the concept of the “Quality of the Acoustics” of a concert hall will be considered in a broader context, thereby including aspects like the “Quality of Communication” in the hall. Type and quality of the information carrier in the light of the cognitive background of the listeners will be discussed, as well as the influence of visual, tactile, and olfactory cues on the quality assessment of concert halls.
Tonality calculation with modified DIN standard
Authors: Oetjen Arne , van de Par Steven
Published: June 2017

Many natural sounds emitted by rotating machinery such as gearboxes, turbochargers, electrical motors or generators contain tonal parts. In the German standard “DIN 45691” a fft-based method for calculating the amount of perceived tonality in a complex sound is suggest that is based on the level difference between the tonal component and the noise in the surrounding critical band. Although the calculation method from DIN 45691 coincides well with subjective ratings for most stationary sounds, it often fails for sounds containing tonal components with rapid frequency changes such as turbochargers, due to the length of the analysis window. A pre-processing stage using shorter analysis windows was implemented that was still able to estimate precise frequencies and amplitudes of tonal components. The method is based on obtaining accurate frequency estimates of tonal components from dividing the spectra of the time differentiated signal and the original signal and is a modification of the method of [Desainte-Catherine and Marchand, J. Aud. Eng. Soc., 48, 654-667]. A post-processing stage using tracking and peak-picking algorithms was added to remove detected tonal components too short for being audible. This method allows both for high temporal and spectral resolution in the estimation of tonal components.
Status quo of standardizing tonality calculation of stationary and time-varying sounds
Authors: Sottek Roland
Published: June 2017

For many years in various applications of noise assessment, tonality measurement procedures such as the Tone-to-Noise Ratio (TNR), Prominence Ratio (PR), and DIN 45681 Tonality have been applied to identify and quantify prominent tonal components. Especially through the recent past as product sound pressure levels have become lower, disagreements between perception and measurement have increased across a wide range of product categories including automotive, Information Technology, and residential products. One factor is that tonality perceptions arising from spectrally elevated noise bands of various widths and slopes and from non-pure tones as well as from discrete (pure) tones, and from combinations of these, can be mis-measured or escape measure in “hybrid” sound pressure based tools and tools sensitive only to discrete tones. To address such issues, a new perceptually adequate tonality assessment method based on a hearing model of Sottek was developed which evaluates the nonlinear and time-dependent loudness of both tonal and broadband components, separating them via the autocorrelation function (ACF) and giving their spectral relationships. This new perception-model-based procedure, suitable for identifying and ranking tonalities from any sources, is proposed for the next edition of ECMA-74 as an alternative to the existing methods TNR and PR (ECMA-74, Annex D).
Can partial loudness of the tonal content be the basis for tone adjustments?
Authors: Verhey Jesko L. , Hots Jan
Published: June 2017

Environmental sounds containing tonal components are more annoying than those without audible tonal components. This is considered in several standards addressing the assessment of noise immissions. These standards have in common that the strength of the tonal component, referred to as tonality, tonalness, or magnitude of tonal content is taken as the level of the prominent audible tone relative to the surrounding background noise. Based on this magnitude of tonal content, some standards add tone adjustments to the measured sound levels to account for the reduced acceptance of a sound with audible tonal components. On the basis of experimental data and model predictions, the present study shows that the magnitude of the tonal content is better characterized by its partial loudness than by the signal-to-noise ratio of the prominent tonal component. Partial loudness of the tonal component may be considered in future standards as a basis for the assessment of the annoyance of the tonal content of a sound and thus the determination of a tone adjustment.
Dr. Kenneth J. Plotkin: Friend and mentor
Authors: Salamone Joseph A.
Published: June 2017

Dr. Kenneth J. Plotkin was the chief scientist at Wyle and was known in the acoustics community as an expert in many aspects of aircraft and transportation noise. He was also widely regarded as an authority on the subject of sonic booms. His enthusiasm for research and new discoveries was contagious—it was almost impossible not to be influenced by his example. He was very willing to share his expertise with those who also ventured into the realm of sonic boom propagation. It is an honor to be one of the people who benefited from his willingness to share his wisdom and learn from his teaching. An initial discussion with Dr. Plotkin inquiring about his knowledge of the rise time of shocks in sonic booms developed into friendship and mentoring that lasted almost 14 years. This presentation will highlight these early conversations and share how they evolved over time. Additionally, the impact he made on my engineering career and graduate school education will also be presented. [Acknowledgments to the National Aeronautics and Space Administration, Federal Aviation Administration, The Pennsylvania State University, Wyle, and Gulfstream Aerospace Corporation.]
Dr. Kenneth Plotkin’s myriad contributions to the National Aeronautics and Space Administration’s supersonic mission
Authors: Haering Edward A.
Published: June 2017

The world as a whole, and NASA, in particular, owes a large debt of gratitude to Dr. Kenneth Plotkin for his decades of service in the field of sonic boom research and advancement of quiet supersonic transportation. This presentation will highlight the contributions of Dr. Plotkin to a myriad of NASA projects. One of the largest efforts was the assembly and continual improvement of sonic boom propagation software tools, collectively called PCBoom, which allowed the analysis of real and imagined vehicles from Mach cutoff conditions to the hypersonic. He was a driving force behind reshaping aircraft to demonstrate quieter sonic booms, first with the plans for a modified Firebee drone and SR-71, and then with the highly successful Shaped Sonic Boom Demonstrator series of flights. Dr. Plotkin’s partnership with NASA Armstrong resulted in the development of the low boom dive maneuver to allow quiet sonic boom testing on structures and people using existing aircraft, as well as a sonic boom cockpit display that has recently been tested in flight. Dr. Plotkin was also instrumental in such research campaigns as SCAMP, WSPR, and FaINT. Throughout all, Dr. Plotkin’s phenomenal intellect, tireless dedication, and irreverent humor made working with him a joy.
Recollections from four decades of sonic boom research with Dr. Kenneth J. Plotkin
Authors: Maglieri Domenic J.
Published: June 2017

Every so often the technical community is blessed to have a very special & talented individual join its folds. In the past half century, the issue of sonic boom needed such a talent who would provide leadership and pioneering contributions to the understanding of the sonic boom, its generation, propagation, prediction, and minimization and its effect on people and structures. Ken was that person. This presentation is of a personal note touching on a few recollections of working with Ken for over 45 years. It will begin with my introduction to Ken in 1970, highlight a key ingredient to his 1971 doctorate thesis & reflect on the significance of his findings, his initial reaction to the 1990 review of his AIAA Journal of Aircraft paper, the coauthoring of a chapter on sonic boom in 1991,our views on need to demonstrate the persistence of a shaped signature, & whether signature shaping will minimizing the transition focus boom, our discussions on whether booms are observed from subsonic flight, & a listing of the boom efforts we enjoyed & publications we coauthored. I miss Ken, his enthusiasm & entertaining ways, his brilliance. I believe he deserves a place alongside G. B.Whitham, A. R.Seebass, & A. R.George.
Kenneth Plotkin——Military noise and sonic boom
Authors: Downing Micah
Published: June 2017

As a young researcher at the Air Force Research Laboratory, I was blessed with the good fortune of working with Ken on a variety of military sonic boom and aircraft noise projects. His mentorship on sonic boom theory required patience on his part but resulted in a successful collaboration, which included an improved PCBoom model and focused sonic boom measurements. From this work, we demonstrated how to make sonic booms louder unlike his later efforts to help minimize future aircraft's sonic booms. Ken also led major upgrades to the military’s aircraft noise model, NoiseMap. His work resulted in the development of the simulation noise model, NMSim and its noise animations. Through Ken’s efforts, we now have tools to better explain sonic boom and aircraft noise. As my mentor, I hope to share some highlights of working with Ken.
Personal memories of Ken Plotkin
Authors: Miller Nicholas P.
Published: June 2017

Ken and I were competitors, co-participants in conferences and professional societies and, occasionally, co-workers. Our times together at meetings or on projects covered about ten years starting in the late 1990s. We worked together on projects for the National Park Service, and spent many meetings of SAE Committee A21 together. These times permitted us to become well-acquainted with each other, and to develop mutual respect for each other's experience and knowledge. We were almost exact contemporaries, being the same ages and starting our careers at almost the same time—Ken at Wyle and I at BBN. Our experiences were somewhat different, with Ken working mostly on military noise issues and I on general transportation noise. We each worked with expert mentors on the our respective coasts; Ken working with Lou Southerland and others in California, I with Ted Schultz, Dick Bolt, and others in Massachusetts. From these times, we enjoyed each other's company, learned a lot from each other, and made memories.
Acoustophoresis mediated chromatography processing: Capture of proteins from cell cultures
Authors: Kennedy Thomas , Pluskal Malcolm , Gilmanshin Rudolf , Lipkens Bart
Published: June 2017

Chromatographic purification of target biomolecules is an important downstream process step in the development of new therapeutic agents, such as antibodies. This step employs chromatographic processes, such as affinity separation utilizing Protein A, ion exchange, or mixed mode chemistries. The workflow typically involves a packed column(s) and several chromatographic steps to achieve the desired level of purity. The steps can be time-consuming and expensive. A new process will be described, employing an acoustic standing wave in a fluid chamber to partition and maintain solid phase beads in an acoustically fluidized bed format to capture, wash, and elute the target biomolecule. Purification workflow(s) will be described for the following applications: (1) capture of a monoclonal antibody by Protein A beads from a crude cell culture system, (2) capture of recombinant Green Fluorescent protein (GFP) by anion exchange from a crude cell lysate. The workflow will include wash step(s) and recovery with a specific elution conditions. This communication will clearly demonstrate that an acoustophoresis process can purify proteins without a packed chromatography column. This new approach will minimize the time and cost involved in current purification workflows.
Experimental analysis of backscattering by cylindrical shell with internal plate at oblique incidence
Authors: Tong Yunzhe , Wang Bin , Fan Jun
Published: June 2017

Through an experimental approach, this paper studies the flexural wave coupling on a cylindrical shell with internal structural. Impulse response backscattering measurements are presented and interpreted for the scattering of obliquely incident plane waves by a fluid-loaded stiffened cylindrical shell and a corresponding empty cylindrical shell respectively. The stiffened cylindrical shell is reinforced by a thin internal plate which is diametrically attached to the shell along its axial direction. The time series data are fast Fourier transformed and the modulus normalized according to the direct wave spectrum. Result are plotted as frequency-angle spectra. Compared with that from the corresponding empty cylindrical shell, the subsonic flexural waves on the cylindrical shell will interact between the attachments and some of their energy can be converted into radiating waves.