bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrasonic characterization of cohesive and adhesive properties of adhesive bonds
Authors: Castaings Michel , Siryabe Emmanuel , Renier Mathieu , Meziane Anissa , Galy Jocelyne
Published: October 2015

The increasing use of adhesively bonded joints requires non-destructive evaluation methods to be developed, mostly for safety reasons. An adhesive joint can be divided into two sensitive zones that may cause mechanical failure: the body of the adhesive layer (cohesive zone) and the interphase between that adhesive and one of the substrate (adhesion zone). Weaknesses of these cohesive or adhesive zones can come, for example, from an incomplete curing of the adhesive or from inappropriate, initial treatment of the substrate surface, respectively. The present research attempts to characterize mechanical properties, which are representative of the adhesive and cohesive states of adhesively bonded assemblies, using a through-transmission ultrasonic method. To simplify the approach, the assemblies are made of two aluminum substrates and an epoxy-based adhesive layer. Six samples have been manufactured with various levels of cohesion or adhesion. Inverse problems are then solved to infer the elastic moduli of the adhesive or stiffness coefficients, which are modeling the interfacial adhesion. The potential, limits, and outlook of the proposed method are discussed.
Improving robustness of damage imaging in model-based structural health monitoring of complex structures
Authors: Masson Patrice , Quaegebeur Nicolas , Ostiguy Pierre-Claude , Moghadam Peyman Y.
Published: October 2015

Model-based Structural Health Monitoring (SHM) approaches offer higher resolution in damage detection and characterization. However, the performance of damage imaging algorithms relies on the quality of the model and the proper knowledge of its parameters, which might prove challenging to obtain for complex structures. In this paper, models are first compared for ultrasonic guided wave generation by bonded piezoceramic (PZT) transducers, from the well-known pin-force model to analytical approaches taking into account the detailed interfacial shear stress under the PZT, and including an electro-mechanical hybrid model. Then, the modeling of guided wave propagation in complex structures is investigated, more specifically in composite structures, considering: (1) dependency of phase velocity and damping on the angle, (2) steering effect due to the anisotropy of the structure, and (3) full transducer dynamics. Validation of the models is conducted on isotropic and composite materials, by comparing amplitude curves and time domain signals with simulation results from Finite Element Models and with experimental measurements using a 3D laser Doppler vibrometer for principal and non-principal directions. Finally, the sensitivity of the damage imaging algorithms to variability in the model parameters is studied, and the benefit of identifying those parameters in-situ, prior to damage imaging, is demonstrated.
Using vector sensors to measure the complex acoustic intensity field
Authors: Dall'Osto David R. , Dahl Peter H.
Published: October 2015

The acoustic intensity vector field, defined as the product of pressure particle velocity fields, describes the flow of energy from an acoustic source. Following a brief introduction of acoustic vector sensors, which includes some direct measurements of acoustic intensity, the intensity field is shown to be composed of active and reactive components. Active intensity streamlines depict the time-averaged flow of acoustic energy and reveal characteristics of acoustic propagation including environmental influences. These streamlines do not characterize reactive intensity, which corresponds to the portion of acoustic intensity that time-averages to zero. Reactive intensity is significant in the near-field of a source and in environments where multipath interfere occurs. To examine the interplay between active and reactive acoustic intensity, the acoustic field generated by an airborne source positioned well above a water surface is presented. Acoustic measurements of a passing airplanes, made simultaneously above and below this sea-surface, are used to demonstrate properties of active and reactive intensity, including how reactive intensity can serve as an indicator of source altitude and range.
Cantilever-based acoustic velocity sensors
Authors: Bucaro Joseph A. , Lagakos Nicholas , Houston Brian H. , Zalalutdinov Maxim
Published: October 2015

This paper discusses progress made on the design of an acoustic velocity sensor. An analytic model was developed for the frequency response of a slender cantilever rod forced by the pressure gradient and particle velocity associated with an acoustic wave propagating in a fluid. The model, validated with acoustic response measurements in air, was used to design cantilever sensors, which respond predominately to acoustic particle velocity. One such design utilizes a short cantilever formed from a 125 μm silica glass fiber immersed in a viscous fill fluid whose lateral tip displacement is detected using a multi-fiber optical probe. This velocity sensor is predicted to be able to detect fairly low acoustic sound levels in water. Progress has been made in instrumenting a large pool at NRL to allow accurate propagating acoustic wave response measurements in water of these new velocity sensors down to frequencies below 5 Hz. Measurements made in this facility on various cantilever sensors will be presented and discussed. [Work supported by ONR.]
Sound amplification at T-junctions with merging mean flow
Authors: Åbom Mats , Du Lin
Published: October 2015

This paper reports a numerical study on the aeroacoustic response of a rectangular T-junction with merging mean flow. The Mach number of the grazing flow in the main duct is fixed at 0.1. The primary motivation of the work is to explain the phenomenon of high level sound amplification, recently seen experimentally, when introducing a small merging bias flow. The acoustic results are found solving the compressible Linearized Navier-Stokes Equations (LNSEs) in the frequency domain, where the base flow is first obtained using RANS with a k-ε turbulence model. It is found that the base flow changes significantly with the presence of a small bias flow. Compared to pure grazing flow, a strong shear layer is created in the downstream main duct, starting from the T-junction trailing edge. That is, the main region of vortex-sound interaction is moved away from the junction to a downstream region much larger than the junction width. The flux of fluctuating enthalpy is calculated to estimate the acoustic source power due to the fluid sound interaction.
Methodology for teaching synthetic aperture sonar theory and applications to undergraduate physics and oceanography majors
Authors: Korman Murray S. , Mullen Caitlin P.
Published: October 2015

Undergraduate senior level physics majors taking Acoustics and oceanography majors taking Underwater Acoustics and Sonar learn about transmitting and receiving arrays (in one unit of their course) and do laboratory experiments to support and enhance the theoretical developments. However, there is a need to expose the students to a detailed unit on synthetic aperture sonar (SAS) while research at USNA is in progress and a teaching laboratory workstation is being developed. This paper communicates the teaching strategy on the topics describing: (a) how a strip-mapped SAS system works, (b) how matched-filtering relates to pulsed compression for a linearly modulated (LFM) pulsed chirp, (c) how synthetic aperture resolution is vastly improved over a conventional acoustic array, (d) how Fourier analysis is used in SAS, and (e) how a data set of N echoes can be used within a back-projection algorithm to obtain a two dimensional reflectivity image of an area (sea floor). Key points are (1) theory with visualizations to convey the teaching material to seniors in a two week period of time, (2) computer simulations, (3) classroom demonstrations in a water tank or in air, and (4) student involvement in a mini-research project using the computers and demonstration apparatus.
Standards-based assessment and reporting in introductory acoustics courses
Authors: Morrison Andrew C.
Published: October 2015

Standards-based assessment and reporting (SBAR), also referred to as standards-based grading and other names, is a system for tracking student learning in a course and assigning a grade. SBAR replaces traditional grading systems by eschewing points-based assignments and evaluations. Instead, students are assessed over specific learning objectives called standards. SBAR has several advantages including: emphasis on topic mastery, development of intrinsic motivation for learning, and simplifying the grading process. I have implemented SBAR in an introductory acoustics course for music technology, sonography, and general education students. In order to change from a traditional grading system to SBAR several steps were taken. Standards were developed, assessments were written, and course policies were drafted. I will discuss the system as implemented, some of the challenges faced, and suggest ways in which the acoustics education community might provide support for others wanting to implement SBAR in their courses.
Evolution of experiential learning in an acoustics elective course
Authors: Ludwigsen Daniel
Published: October 2015

Starting in 2007, PHYS-388, Acoustics in the Human Environment, has been part of the Acoustics Minor at Kettering University. Originally envisioned to capture foundational concepts of acoustics that would be essential to a wide variety of engineering and scientific applications, this course is aimed at a junior/senior level audience to reflect the initiative and maturity required of the student. Topics emphasize the interdisciplinary nature of acoustics in industry, incorporating digital signal processing, psychoacoustics, and applications in room acoustics and environmental noise. Its evolution from a face-to-face studio environment to a hybrid, and then fully online course has retained a hands-on experiential course design and themes of art and design. Challenges arose in teaching the course online, and solutions to promote learner engagement and consistency are described.
Physics of music field trips
Authors: Ioup Juliette W. , Ioup George E.
Published: October 2015

Many studies on educational techniques have shown that students learn best when they are actively engaged. In introductory physics classes, this means each student makes measurements and performs calculations; in music performance classes, this means each student practices a musical instrument and analyzes music scores. In the two-semester sequence of Physics of Music lectures and laboratories taught at UNO, students participate in a variety of hands-on activities, including measuring quantities for available musical instruments and then calculating various physical parameters from the measured values. Another helpful activity is going on “field trips” to other locations, such as the auditorium in the UNO Performing Arts Center (once to study the concert grand piano there and once to make room acoustic measurements), the small recording studio on campus (lecture given there by the UNO recording engineer demonstrating various types of equipment), and to a chapel across the street from campus (pipe organ demonstrated by the organist of the chapel, acoustic measurements made by students). An extra benefit is that these trips are attractive to both non-science and science students, assisting in both recruitment and retention. Suggestions for and cautions about various field trips from experiences teaching these courses will be presented.
The science of adhesion
Authors: Logan Roger M.
Published: October 2015

This presentation is designed to promote the study of science to pre-college audiences. It has been well-received at a variety of pop culture conventions by attendees that vary from high school students interested in building better costumes to NASA Ph.D.’s whose mission is to build better satellites. ASA attendees will be strongly encouraged to use this (or a similar) presentation as an outreach tool to help recruit the next generation of STEM scholars.
Assessing acoustic reflexes for impulsive sound
Authors: Flamme Gregory A. , Tasko Stephen M. , Deiters Kristy K. , Ahroon William A.
Published: October 2015

The acoustic reflex is an involuntary contraction of the middle ear muscles in response to a variety of sensory and behavioral conditions. Middle ear muscle contractions (MEMC) have been invoked in some damage-risk criteria for impulsive noises for over 40 years and one damage-risk criteria proposes that MEMC precede the impulse for a warned listener via response conditioning. However, empirical data describing the prevalence, magnitude, and time-course of reflexive MEMC elicited by impulsive stimuli as well as non-acoustic stimuli and behaviors are scant. Likewise, empirical support for anticipatory MEMC is limited and studies often fail to control for attention or concomitant muscle activity. The current study is a large-scale, multi-experiment project designed to address these limitations in a laboratory and field environment. MEMC are detected using click train stimuli as probes. Reflexive MEMC are elicited using tones, recorded gunshots, and non-acoustic stimuli (e.g., controlled release of compressed nitrogen gas to the face). Anticipatory MEMC are assessed across varying levels of distraction, beginning with participant instructions to pay attention to the conditioning stimulus and culminating in the assessment of anticipatory MEMC during live-fire exercises with rifles.
Damage risk criteria for high-level impulse noise and validation data
Authors: Dancer Armand L.
Published: October 2015

The existing DRCs for high-level impulse noise will be briefly described along with their relative merits. Classical DRCs (CHABA, Mil-STD 1474D Z-curves, Pfander, Smoorenburg...) overestimate the hazard of large weapons, do not assess the actual efficiency of the HPs, and are not compatible with the occupational DRCs. The AHAAH model is potentially very powerful. However, the model needs to “know” the exact pressure-time history of the impulse at the subject's ear and the human middle ear transfer function for high-level impulses. Unexpected artifacts of measurements send the model on wrong tracks! Last but not least the “parameters” of this model need to be “adjusted” to be in agreement with the experimental results obtained on a large number of soldiers (to be presented). The LAeq8 method with a limit of 85 dB allows a limitation of the hearing hazard comparable to that aimed at by the other DRCs. It allows the assessment of the hazard for all kinds of weapon noises (free field and/or reverberant conditions) and for combined exposures (impulse and continuous noise) either on protected or unprotected ears. Finally, the auditory hazard is evaluated along the same rules in the military and in occupational exposures (ISO 1999).
LIAeq100ms, An A-duration adjusted impulsive noise damage risk criterion
Authors: McKinley Richard L.
Published: October 2015

Impulsive noise damage risk criteria (DRCs) have been the subject of much debate nationally and internationally for more than 30 years. Several approaches have been used in proposed DRCs including: curves defining exposure based on peak level and A or B duration; auditory hazard units based on the analytical auditory model known as AHAAH; and LAeq metrics based on the equal energy concept. Each of the approaches has positive and negative attributes. One of the issues with LAeq metrics has been the over estimation of hazard with long duration impulses such as those coming from blasts, artillery, large mortars, or shoulder launched missiles. The presentation will describe and discuss the LIAeq100ms impulsive DRC which includes an adjustment based on the A-duration of the impulsive noise and a method of computing protected impulsive noise exposures using impulsive insertion loss data from hearing protectors measured with methods defined in ANSI S12.42.
Development of the auditory hazard assessment algorithm for humans model for accuracy and power in MIL-STD-1474E's hearing analysis
Authors: Price G. R. , Kalb Joel T.
Published: October 2015

MIL-STD-1474E uses the Auditory Hazard Assessment Algorithm for Humans (AHAAH) model to calculate hazard from intense impulses, its theoretic basis providing greatly increased power and accuracy. It is an electro-acoustic analog paralleling the ear’s physiology, including the ear’s critical non-linearities and it calculates hazard from basilar membrane displacements. Successfully developed and tested first with an animal model, a parallel version for the human ear was developed and validated with human data. Given a pressure history as input, AHAAH predicts hazard for the 95%ile susceptible ear. It also makes a movie that allows engineering insight into amelioration of hazard. Hearing protection is accommodated by using input from an acoustic manikin or by implementation of a mathematical protector model using REAT data to calculate input waveforms from free field data. The AHAAH model is also currently used by the Society of Automotive Engineers for calculation of airbag noise hazard, by the Israeli Defense Forces for impulse noise analysis and is being considered by ANSI's S3 Bioacoustics Committee Working Group 62 (Impulse Noise with Respect to Hearing Hazard) as a basis for an ANSI impulse noise standard.
Investigating coupled flow-structure-acoustic interactions of human vocal fold flow-induced vibration
Authors: Thomson Scott
Published: October 2015

Flow-induced vibration of the human vocal folds is a central component of sound production for voiced speech. During vocal fold oscillation, tightly coupled flow, structure, and acoustic dynamics form a system that is rich in multi-physics phenomena, such as large deformation and large strain of exceedingly flexible and multi-layered tissues, repeated collision between vocal folds, coupling between structural modal frequencies and acoustic resonances, and the presence of non-trivial flow features such as the Coanda effect, flow separation, and axis switching. One of the aims of voice production research is to better understand these physical phenomena. In this presentation, tools and techniques for studying vocal fold flow-structure interactions will be discussed. Synthetic vocal fold replicas that exhibit flow-induced oscillations comparable to those of the human vocal folds will be introduced. These replicas are fabricated using three-dimensional prototyping, molding, and casting techniques, in which the multi-tissue layer structure of the human vocal folds is simulated using multiple layers of silicone of differing material properties. Experimental techniques used to characterize replica dynamic responses will be presented. Computational models that include fully coupled fluid, solid, and acoustic domains to simulate vocal fold vibration will be introduced. Several applications of these models and approaches will be discussed.
Experimental investigation of the acoustic damping of In-duct orifices with bias flow
Authors: Ji Chenzhen , Zhao Dan
Published: October 2015

Geometry of orifice is investigated by the experiments to evaluate the acoustic damping capacity of orifice plates in a duct. Four kinds of plates with complex orifice shapes are fabricated by using modern 3D printing technology. To characterize acoustic damping performance of these plates, sound absorption coefficient is used as an index determined by using the classical two-microphone technique. It is found that the geometric shapes of the perforated orifices can affect their sound absorption performances, and the damping performances of different shaped orifices depend on the frequency range. The length of downstream duct is also proven to determine the damping performance of perforated plates. The shorter the downstream pipe length, the narrower frequency range corresponding to lower power absorption. Moreover, the bias flow is shown to play a critical role on the sound absorption capacity of orifice plate in the experiments. Sound absorption coefficient is found to increase first and then decreased with increased Mach number.
Utterance-initial voiced stops in American English: An ultrasound study
Authors: Ahn Suzy
Published: October 2015

In English, phonologically voiced consonants are often phonetically voiceless in utterance-initial position. Other than Westbury (1983), there is little articulatory evidence regarding utterance-initial voicing in American English. The current study uses ultrasound imaging and acoustic measures to examine how tongue position correlates with phonation in American English, comparing phonated voiced stops, unphonated voiced stops, and voiceless stops in utterance-initial position. Eight speakers of American English recorded voiced/voiceless stops at three places of articulation (labial, alveolar, and velar), in three different environments (utterance-initial, post-nasal, and post-fricative), and with two different following vowels (high/low). One adjustment for initiating or maintaining phonation during the closure is enlarging the supraglottal cavity volume primarily via tongue root advancement. In utterance-initial position, there was a clear distinction between voiced stops and voiceless stops in the tongue root for the alveolar and velar places of articulation. Even without acoustic phonation during closure, the tongue root is advanced for voiced stops in comparison to voiceless stops for supraglottal cavity enlargement. These results suggest that speakers have the same target for both phonated and unphonated stops in utterance-initial position (i.e., shorter VOT), but other articulatory adjustments are responsible for the presence or absence of phonation.
Aerodynamic factors for place-dependent voice onset time differences
Authors: Eshghi Marziye , Alemi Mohammad Mehdi , Zajac David J.
Published: October 2015

Studies have shown that voice onset time (VOT) tend to increase as place of articulation moves further back in the oral cavity. Different aerodynamic factors have been postulated for place-dependent VOT differences; although no direct aerodynamic measures have been reported in this regard. The objective of this study was to investigate aerodynamic factors which lead to variation of VOT according to place of articulation. The speech materials of the study were /pa, ta, ka/, each produced 30 times by an adult female (27 yrs) in the carrier phrase “say -- again”. SPL was targeted within a ±3 dB range. Intraoral air pressure (Po) was obtained using a buccal-sulcus approach. VOT, Po, and maximum Po declination rate (MPDR) were measured for each stop. Results showed that: (a) the further back the place of articulation, the longer the VOT; (b) Po was greatest for the velar stop, intermediate for the alveolar stop, and smallest for the bilabial stop; and (c) the MPDR index showed slower pressure drop for the velar stop compared with the other two stops. Results provide empirical evidence for the role of oral pressure differences, mass of articulators, and cross-section area of the constriction in place-dependent variations of VOT.
Degree of articulatory constraint predicts locus equation slope for /p,t,s,∫/
Authors: Perillo Sara , Bang Hye-Young , Clayards Meghan
Published: October 2015

The degree of articulatory constraints (DAC) model (Recasens, Pallarès, & Fontdevila, 1997) proposes that consonants involving the movement of the tongue dorsum are more resistant to coarticulation than those with a more fronted articulation. We assessed this claim using locus equation (LE) slopes as indicators of coarticulation. Participants were asked to produce V1(t).CV2 sequences as part of two-word phrases in a scripted dialog, where C is one of /p, t, s, ʃ/. LE were derived by measuring F2 at V2 onset and midpoint. Since LE slopes approaching 1 indicate high levels of coarticulation, it was hypothesized that segments with the lowest DAC would have the steepest slopes (/p/>/t/>/s/>/ʃ/) and this is what we found, lending support to the DAC model. A secondary hypothesis assessed the effect of emphatically stressing C on the LE. Participants partook in a dialog involving a “mishearing” of either the target C (Prominent condition) or the preceding V1(t) (Control condition), and they repeated the two word sequence. We expected participants to emphasize the misheard segment and reduce coarticulation if the C was misheard (lower LE slope). Our findings indicate that only the LE slopes of sibilants /s/ and /ʃ/ were reduced under prominence, perhaps due to their high DAC values.
A dual task study of the effects of increased cognitive load on speech motor control
Authors: Dawson Katherine M. , Bomide Grace , Tiede Mark , Whalen DH
Published: October 2015

Research has shown that behavioral task performance suffers when cognitive load is increased. One method for observing this phenomenon is the so-called dual task paradigm, which has been applied in previous research manipulating the motor, linguistic, and cognitive demands of speech tasks [Dromey & Benson, JSLHR, 46(5), 1234–1246 (2003)]. Trade-offs between (and within) domains necessary to maintain task performance probe sensitivity to increased load and the nature of variability in speech (i.e., does speech become more or less variable in increased load situations). In the current study, cognitive load on a speech motor task (mono- and di-syllable repetition) is manipulated using simple, competing memory, visual attention, and inhibition tasks, with concurrent recording of speech acoustics and kinematics. A preliminary analysis of acoustic data from five participants measured duration, amplitude and F0 of utterances during the single and dual task conditions. Results from the dual task conditions suggest a complex trade-off between the amplitude, duration and F0 measures, which differed systematically among the memory, attention, and inhibition tasks. In contrast, the baseline speech measures varied idiosyncratically among participants. Analysis of kinematic data should assist in clarifying how the interactions among these variables are affected by the different types of cognitive load.
Assessing vowel centralization in dysarthria: A comparison of methods
Authors: Fletcher Annalise , McAuliffe Megan , Lansford Kaitlin , Liss Julie
Published: October 2015

Previous literature has consistently reported correlations between acoustic vowel centralization and perceptual measurements of dysarthria. However, the strength of these relationships is highly variable, and many of the techniques used to measure vowel centralization have not been directly compared. This study evaluates methods of assessing vowel centralization and listeners’ perceptions of dysarthria—with the aim of strengthening the relationship between these variables. Sixty-one speakers of New Zealand English (NZE; 17 healthy older individuals and 44 speakers diagnosed with dysarthria) read a standard passage. Metrics of vowel centralization were calculated using first and second formants of the [ɐː], [iː] and [oː] NZE point vowels. The results demonstrate that both the use of a flexible formant extraction point, and changes to the frequency unit in which formants are measured, can strengthen the relationship between acoustic and perceptual measures. Furthermore, applying these formant values to different metrics of vowel centralization, and changing the instructions listeners are given to rate dysarthria, can also reduce levels of unexplained variation in the relationship. In combination, these changes accounted for 18–26% more variance between vowel centralization measurements and listener perceptions of dysarthria in both male and female speakers.
Analysis of distinctive feature matching with random error generation in a lexical access system
Authors: Kong Xiang , Choi Jeung-Yoon , Shattuck-Hufnagel Stefanie
Published: October 2015

A matcher for a distinctive feature-based lexical access system is tested using degraded feature inputs. The input speech comprises 16 conversation files from a map task in American English, spoken by 8 female speakers. A sequence of predicted features are produced from a generation algorithm, and the results are randomly degraded at levels from zero to full degradation, for various combinations of the features. Two series of experiments are conducted: the first progressively degrades only single features while leaving all others intact, while the other builds up the system using single, then multiple features. From these experiments, introducing errors into particular articulator-free features, such as vowel, consonant, or sonorant; or articulator-bound features, such as the aspirated feature, pharyngeal features, the nasal feature, the velar feature, or the lateral and rhotic features, do not strongly degrade matching performance. However, matcher performance is more sensitive for errors in the other articulator-free features, and for the articulator-bound features related to vowel place and consonant place, especially, the tongue blade features. For combinations of features, degrading consonantal features, vowel place features, or tongue blade features leads to faster decline in performance, suggesting that these features play more important roles in lexical access.
High-frequency, vertically directional short-range underwater acoustic communications
Authors: Edelmann Geoffrey F. , Emokpae Lloyd , Freeman Simon E.
Published: October 2015

The underwater acoustic channel is a challenging environment for achieving high data rate communications due to multipath, attenuation, noise, and propagation delay. Performing and maintaining adaptive channel equalization requires significant computational overhead, leading to costly and power-hungry devices. Here we describe a low-cost reconfigurable acoustic modem platform (RAMP) intended to facilitate a cable-less benthic hydrophone array made from inexpensive and replaceable nodes. The high data rate acoustic modem is modulated on a carrier frequency of 750 kHz via binary phase shift keying (BPSK). Each modem is spaced approximately 10 m from adjacent units. Due to the vertical directivity of the transducer the half-maximum envelope of the main lobe is approximately 3°, thereby mitigating multipath from the bottom. Data at rates of up to 125 kbps will be shown from at-sea experimental measurements made in Panama City Beach, Fl. [This work was supported by the Office of Naval Research.]
The rear end collision and the wheel flying off protection using the reinforcement learning with the adaptive sound caution
Authors: Okada Kazuhide
Published: October 2015

Safety driving is to watch both the front and the side from the driver seat. In order to avoid a rear end collision for the other car and a wheel flying off its axle for the said car itself at the same time, Q-learning of reinforcement learning was used in this study. In this study, the image of the front whole window is always captured by camera. Here, a steering angle divided by eight categories toward the front is the action at of a wheel flying off protection and car speed divided by ten categories is that of the rear end collision protection. The status st is distance from the sideview mirror to the side ditch for the wheel flying and the length between the roof of the car which is running ahead and its rear bumper. In the training phase, so as to maximize the sum of the rewards taken from the environment as the vehicle's front window, the system updates the recursion Quantity of a state action combination Q(st,at) = Q(st,at) + α (rt + 1 + γ max[a]Q(st + 1,a) − Q(st,at)) (t:time, α:learning rate, γ: discount) periodically until its Q(st, at) value is converged individually. When rewards both for the rear end collision and wheel flying off become mature, the automatic operating routines are regarded to be completed. And when making use of this system, the code still watches the car distance from the ditch and the relative level of the front car and the adaptive caution sound which has three spectrum peaks along 0.5 through 6 kHz are rung, adjusting frequency, loudness, and duty corresponding to the severity if the car approaches the crisis.
Electric guitar—From measurement arrays to recording studio microphones
Authors: Case Alexander U. , Anderson Jim , Roginska Agnieszka
Published: October 2015

A joint research effort by the audio recording programs at the University of Massachusetts Lowell and New York University has made use of a 32-microphone measurement array in the quantification and visualization of the spectral radiation of musical instruments. Work to date has focused on electric guitar and piano. The measured directivities of the guitar amplifiers offer rich insight for the recording engineer. Traditional microphone selection and placement strategies formed over decades, before such data existed, are found to have merit. The data also shed light on those potentially unattractive microphone locations to be avoided. The measurements, taken with high spatial resolution, reveal a process for microphone placement as much as providing a window into showing exactly where to place them. Measurements of the acoustic radiation from electric guitar amplifiers reveal a spatial complexity that many recording engineers anticipate, and add valuable further insight.
Measurement of loud noncontinuous exterior noise sources on patients
Authors: Holtrop James S.
Published: October 2015

A method to measure non continuous exterior noise sources such as helicopters, waste removal trucks, emergency vehicles, and semi-trucks will be presented. The noise levels that can be generated by these sources can exceed 90 dBA, which can impact patients within the hospitals. As hospitals are 24 hour facilities these sources of noise can happen during both daytime and nighttime hours. Data will be presented on the various acoustical methodologies to quantify this type of noise to access the impact on patients in the hospital.
Permanent sensor-based hospital noise discovery
Authors: Bialk John
Published: October 2015

John Bialk, CEO of Quietyme, will discuss how using smart sensors and advanced analytics to measure sound levels in hospitals has revealed what really happens in healthcare settings. By measuring decibel levels once per second in every patient room, hallway, and nurse’s station, Quietyme is able to uncover the exact sources of patient noise disturbances and better understand solutions to reduce them. With nearly 100 million points of hospital sound data, John Bialk has a rare and purely objective perspective on hospital noise and will explain the difference between what the data has revealed and common misconceptions. In addition, Quietyme has helped with a variety of noise studies testing rooms and John will reveal findings that relate to hard surface vs. carpet, healthcare noise levels during construction and more.
How flying CF-FM echolocating bats adapt to acoustically jammed environments: Quantitative evaluation
Authors: Goto Daiki , Hiryu Shizuko , Kobayasi Kohta I. , Riquimaroux Hiroshi
Published: October 2015

Echolocating bats face the acoustical interferences from sounds of other conspecifics; they can fly without colliding each other and avoid surrounding obstacles. The purpose of this study was to reveal how CF-FM bats extract their own echoes in acoustically jammed environments. The Japanese horseshoe bats (Rhinolophus ferrumequinum nippon) were flown with conspecifics in the flight chamber. As the number of flying bats increased from one to seven, the duration of constant frequency (CF) components decreased, whereas the terminal frequency modulated (TFM) components were extended in both time and frequency ranges. In order to quantitatively evaluate behavioral responses under jamming conditions, a flying bat was exposed by artificially synthesized CF-FM pulses. As a result, the bats also changed the CF and TFM components as observed in the group flight experiment. This shows that the bats modify the characteristics of pulses to adapt to acoustical jamming and not to adapt to spatial jamming owing to other flying bats. These results suggest that TFM component was more important than CF component in extracting their own echoes during flight in acoustically jammed conditions. We will examine echolocation behavior when we manipulate CF components in context of jamming avoidance during Doppler-shift compensation.
Dynamic baffle shapes for sound emission inspired by horseshoe bats
Authors: Fu Yanqing , Caspers Philip , Müller Rolf
Published: October 2015

Horseshoe bat noseleaves are intricate baffle structures that diffract the animals' ultrasonic biosonar pulses upon emission. Furthermore, horseshoe bats dynamically change the shapes of their noseleaves through muscular actuation. Motions have been previously described for two lancet parts, anterior leaf and lancet. In both cases, the observed motions resulted in changes to the opening angle of the noseleaf baffle. Here, experiments were carried out with simplified baffle shapes that mimic the dynamics seen in horseshoe bats. For the baffle walls to have an effect on the outgoing wavefields, the sound outlets have to be narrow at least in one direction so that their near-fields generate substantial sound pressure amplitudes on the surface of the baffle. The baffle geometry was found to play an important role in the generation of dynamic signatures in the emitted pulses. As the opening of the baffle was varied by small increments, concave baffle surfaces were found to result in much larger dynamic changes to the beampatterns than straight baffles surfaces. Hence, concave baffles were able to introduce large dynamic signatures into the pulses even for small changes in opening angles. This may match the situation in horseshoe bats where the concerned baffles are also concave.
Seeing the world through a dynamic biomimetic sonar
Authors: Caspers Philip , Gaudette Jason , Fu Yanqing , Todd Bryan , Mueller Rolf
Published: October 2015

The outer baffle surfaces surrounding the sonar pulse emission and reception apertures of the biosonar system of horseshoe bats (family Rhinolophidae) have been shown to dynamically deform while actively sensing the environment. It is hypothesized that this dynamic sensing strategy enables the animal, in part, to cope with dense unstructured sonar environments. In the present work, a biomimetic dynamic sonar system inspired by the biosonar system of horseshoe bats has been assembled and tested. The sonar head features dynamic deforming baffles for emission (mimicking the bats’ noseleaf) and reception (pinnae). The dynamic baffles were actuated to change their geometries concurrently with the diffraction of the emitted ultrasonic pulses and returning echoes. The time-variant signatures induced by the dynamic baffle motions were systematically characterized in a controlled anechoic setting and the interaction between emission and reception dynamic signatures was investigated. The sonar was further tested in the context of natural environments with a specific focus on the interaction of dynamic ultrasonic pulse packets with natural targets. For both experimental approaches, a sonar with static baffle shape configuration was used as a reference to establish the impact of dynamic features.
The metabolic costs of producing clicks and social sounds differ in bottlenose dolphins (Tursiops truncatus)
Authors: Holt Marla M. , Noren Dawn P. , Dunkin Robin C. , Williams Terrie M.
Published: October 2015

Dolphins produce many types of sounds known to have distinct qualities and functionalities. Whistles, which function in social contexts, are much longer in duration and require close to twice the intranasal air pressure to produce relative to biosonar click production. Thus, it is predicted that whistle production would be energetically more costly but this prediction is complicated by the fact that clicks are generated at much higher signal intensities. We used flow-through respirometry methods to measure metabolic costs of social sound and click production in two bottlenose dolphins. For all signal types, metabolic rates were related to the energy content of the signals produced. When metabolic costs were compared for equal energy sound generation, clicks were produced at negligible costs relative to resting and at a fraction of the cost of social sound production. However, while the performed repetition rates during click production were similar to field measurements, those of social sounds were much higher compared to typical field values. Even when metabolic costs are adjusted for more realistic whistle repetition rates, results indicate that whistle generation is more energetically costly. These results have implications for predicting the biological consequences of vocal responses to noise under different behavioral contexts.
Effect of noise on each song element in Bengalese finch: Change of acoustic features
Authors: Shiba Shintaro , Okanoya Kazuo , Tachibana Ryosuke O.
Published: October 2015

Certain acoustic features of vocalization involuntarily change in response to the presence of background noise (e.g., the Lombard effect). These changes, observed in many species, are considered to be induced by audio-vocal interaction. Bengalese finch (Lonchura striata var.domestica) is suitable for this study because they need real-time auditory feedback of their own song. By investigating the effect of noise on each distinct element (i.e. notes) of their song, we can get more detailed knowledge about audio-vocal interaction. Here we demonstrate the changes of intensity and fundamental frequency (F0) of notes of Bengalese finches’ songs under noises. Two band-pass noises (High/Low) in two levels (Loud/Soft) were used. The High/Low noises had spectral bands of 4.0–7.8/0.2–4.0 kHz each, and the Loud/Soft noises were set to 70/60 dBA, respectively. As a result, intensity in two High conditions and F0 in High Soft condition increased, while these features of some notes decreased in Low conditions. Also some individual lowered F0 of almost all the notes in all the conditions. The results suggest that the change of these features might depend on the relation between noise frequency and the original note characteristics, and also individual tendency. [Work supported by JSPS KAKENHI #26240019.]
A study of Foley Sound based on analysis and compare of the bird’s chirping
Authors: Iksoo Ahn , Bae Seonggeon , Bae Myungjin
Published: October 2015

This research verifies use value of Foley sound of bird‘s chirping used in Radio drama as sound contents by comparing and analyzing it with Actual sound. Radio drama utilizes sound of bird‘s chirping to show season, time, and place in various ways. Currently, this sound is used as sound effect in media by recording Actual sound of bird‘s chirping on site with portable recorder. Before when no portable recording device existed, they had to make Foley sound. To have comparative analysis of Actual and Foley sound of bird‘s chirping, production method of Foley sound tools and their usage were studied. To conclude, as Foley sound tools used for sound of bird‘s chirping are very unique and interesting there is a high possibility of developing them into Sound contents for Performance and Exhibition.
Rats became positive or negative states when listening to specific vocalizations
Authors: Saito Yumi , Kagawa Hiroko , Yuki Shoko , Okanoya Kazuo
Published: October 2015

Emotional contagion is the process in which one became the same emotional states of the others via a behavioral signal, and many species use acoustic cues as this signal. For example, in human beings, emotional contagion occurs when they get emotional vocalizations of others, like laughter or crying. Likewise, rats emit 50 kHz or 22 kHz specific ultrasonic vocalizations (USVs) associated with positive or negative context. In order to measure whether these acoustic cues have the valence of attractiveness or aversiveness, we utilized the cognitive bias task in rats. Rats were trained to respond differently for two neutral stimuli. One resulted in a positive outcome while the other produced negative outcome. Then the intermediate stimulus between the two was used to test whether that was interpreted as being positive or negative. After the 50 kHz USVs stimulation, rat interpreted the neutral stimuli as being positive, while after the 22 kHz USV stimulation, the same stimuli were regarded as negative. Results suggest that USVs can bring about positive or negative emotional states of listeners, and our findings indicated that specific USVs can work as acoustic emotional signal in the conspecific. [Work supported by JSPS KAKENHI #23118003.]
Ships as sources of opportunity in acoustic source localization
Authors: Verlinden Christopher M.
Published: October 2015

Ships, which can be tracked using the Automatic Identification System (AIS), represent underutilized acoustic sources of opportunity (SOP) that can potentially be used to localize unknown sources, invert for environmental parameters, and extract information about the ocean environment such as the local time dependent Green’s Function. An application of ships as SOP’s used to localize targets is presented here. Rather than use replica fields for matched field processing (MFP) derived from acoustic models requiring detailed environmental input, data derived replicas from ships of opportunity can be used for assembling a library of replicas for MFP. The Automatic Identification System (AIS) is used to provide the coordinates for the replica library and a correlation based processing procedure is used to overcome the impediment that the replica library is constructed from sources with different spectra and will be used to locate another source with it own unique spectral structure. The method is simulated and demonstrated with field experiments. AIS information is retrieved from the Unites States Coast Guard Navigation Center (USCG NAVCEN) Nationwide AIS (NAIS) database.
Inversion of normal mode functions and seabed properties using non-linear time sampling of low-frequency bowhead whale calls on a vertical array
Authors: Thode Aaron , Arisdakessian Cedric , Bonnel Julien
Published: October 2015

Previous research has demonstrated that individual modal components of signals propagating in an acoustic waveguide can be isolated from a single hydrophone using non-linear time sampling (Bonnel et al., 2010) and that mode shape functions can be directly extracted from vertical array data in a laboratory setting (Bonnel et al., 2011). Here, we apply and extend the technique to experimental data collected in 2010 from a 15-element vertical array, covering only 63% of the 53 m water column off the continental slope of the Beaufort Sea, during the fall bowhead whale migration. We demonstrate how up to five distinct mode shapes can be extracted from frequency-modulated bowhead whale calls, along with the vertical array tilt and tilt direction, without resorting to assumptions about mode orthogonality across the array aperture. The extracted mode shapes can then be used to estimate whale call depth. Filtered modes (and mode cutoff information) can also be used to invert for whale call ranges and ocean bottom properties. [Work supported by the North Pacific Research Board and permitted by Shell Exploration and Production Company.]