bluuebunny/crossref_metadata_2025 huggingface dataset:
Three months in Beijing—Micro-perforated absorbers, eigenvalues, and other topics
Authors: Nocke Christian , Hilge Catja
Published: May 2013

In this contribution, a personal and scientific report on a three month exchange stay at the Institute of Acoustics in Beijing will be reported. Micro-perforation and low frequencies in small rooms have been the background of an investigation under supervision of Professor Daa-You Maa in 1999. Maa’s ideas from the 1930s about the distribution on eigenmodes in rooms in combination with micro-perforated absorbers as reference absorbers had been the basis of this work. Abacus and computer calculations as the basis of old/new ideas formed the background of a stay as a student. Even after more than 12 years, micro-perforation is part of the daily work as consultant often dealing with new product ideas and developments. The presentation will give a very brief overview on this work that started in Beijing. Furthermore, in remembrance of a once in a life time experience personal experiences with Professor Daa-You Maa, his wife, and his colleagues will be reported.
Surface waves over rigid-porous and rough surfaces
Authors: Attenborough Keith , Bashir Imran , Taherzadeh Shahram
Published: May 2013

Surface waves are created by near grazing sound propagation from a point source over either a rigid-porous layer or a (slightly) rough surface. In theory, they have similar origins. Frequency- and time-domain measurements have been made on surfaces composed from parallel periodically spaced rectangular strips (width 0.0126 m, height 0.0253 m) on an acoustically hard surface. The edge-to-edge spacing between the strips has been varied between 0.003 and 0.06 m. Frequency domain predictions show that when the spacing is substantially smaller than the strip height these surfaces may be regarded as locally reacting rigid-framed hard-backed porous layers with an effective depth slightly larger than the strip height. When the spacing is comparable to the strip height or greater the surfaces behave as periodically rough surfaces. Both frequency- and time-domain results show that surface waves of comparable magnitudes are created over the range of strip spacings studied but the main frequency content of these acoustically-induced surface waves is lowered as the mean spacing is increased. These data suggest that the surface waves have a similar physical origin and that they can be created also over a micro-perforated surface.
Investigation of sound scattering by a surface using the acoustical wave propagator method
Authors: Pan Jie , Sun Hongmei , Leader James
Published: May 2013

The time domain acoustical wave propagator (AWP) method is used as a tool to study the sound scattering properties of a surface. As the method allows the modeling of the excitation, absorption, and scattering of sound in a vicinity of the surface within a very short period of time, the effect of other surfaces on these process can be ignored, and the acoustical property of a specific surface can be investigated in detail without solving the sound wave equation in the whole space. Sound scattering by a finite impedance strip mounted on a rigid baffle in two different conditions is solved by the method. The result is used to illustrate the efficiency of the method.
Call perception in mice
Authors: Neilans Erikson , Holfoth David , Radziwon Kelly E. , Portfors Christine V. , Dent Micheal L.
Published: May 2013

Acoustic communication in laboratory mice is a relatively recent subject of experimental study, often yielding disparate findings. For example, researchers often manually place mouse ultrasonic vocalizations (USVs) into categories based on spectrotemporal characteristics, but the numbers and types of categories differ widely between laboratories. Here, we attempt to determine what cues CBA/CaJ mice use to discriminate between vocalizations by testing them in an operant conditioning paradigm. The mice were trained to discriminate a repeating background containing one USV from several target USVs. The targets were different call types used by Holmstrom et al. (2010) and manipulations of the background calls, such as removing the frequency modulation, shifting the entire call up or down in frequency, shortening or lengthening the call, or reversing the entire call. Results show that large frequency shifts were easy for the mice to discriminate, while reversing the calls and removing the frequency modulation were much more difficult. For most calls, similarity in spectrotemporal characteristics yielded poor discrimination performance. These results are the first to show that mice can discriminate between some vocalizations but not others, and that they may place different meaning to different call types, though not necessarily the call types designated by humans.
The influence of anthropogenic noise on the evolution of communication systems
Authors: Narins Peter M.
Published: May 2013

Many species of animals, including man, face the formidable task of communicating in noisy environments. In this talk, I shall discuss the effects of anthropogenic (man-made) noise on the calling behavior of anuran amphibians. Moreover, the role of spectral, temporal, and spatial separation in minimizing masking by background noise will be examined. For example, presenting high-level, periodic (or aperiodic) tones at the males co-note frequency to males of the Puerto Rican treefrog, Eleutherodactylus coqui results in a clear shift in their calling pattern in an attempt to minimize acoustic overlap with the interfering playback stimulus. Amphibians also have a remarkable ability to shift their call timing in response to small intensity shifts in the background noise. Males of E. coqui are capable of reliably detecting a change in interfering tone intensity as small as 2–4 dB. Finally, I shall present behavioral evidence that anthropogenic noise may act as a strong selective force in sculpting the acoustic communication systems of several species of Old World frogs. Some techniques for visualizing sound interference will be discussed. [Supported by grants from the NIDCD (Grant No. DC-00222), and the UCLA Academic Senate (3501).]
Active listening in a complex environment
Authors: Wohlgemuth Melville , Moss Cynthia F.
Published: May 2013

Spatially guided behaviors in echolocating bats depend upon the dynamic interplay between auditory information processing and adaptive motor control. The bat produces ultrasonic signals and uses information contained in the returning echoes to determine the direction and distance of objects in space. With this acoustic information, the echolocating bat builds a 3-D auditory representation of the world, which it uses to guide a suite of coordinated motor behaviors, including head and pinna movements, as well as the timing, duration, frequency characteristics, and directionality of sonar signals. Adaptive echolocation behaviors shape the acoustic information available to the bat’s sonar imaging system and provide a window to its perception of complex scenes. In a complex environment, an echolocating bat encounters multiple reflecting surfaces that return a cascade of echoes from each sonar transmission. The work presented here will focus on adaptive echolocation behaviors of the big brown bat as it tracks a selected prey item in the presence of multiple objects, both obstacles and other prey. Data suggest that bats can successfully segregate streams of echoes from closely spaced objects through finely tuned adaptive sonar signal control.
Your attention, please! Determining saliency of competing audio stimuli in natural scenarios
Authors: Tordini Francesco , Bregman Albert S. , Ankolekar Anupriya , Sandholm Thomas , Cooperstock Jeremy R.
Published: May 2013

Perceptual saliency is a precursor to bottom-up attention modeling. While visual saliency models are approaching maturity, auditory models remain in their infancy. This is mainly due to the lack of robust methods to gather basic data, and oversimplifications such as an assumption of monaural signals. Here we present the rationale and initial results of a newly designed experimental paradigm, testing for auditory saliency of natural sounds in a binaural listening scenario. Our main goal is to explore the idea that the saliency of a sound depends on its relation to background sounds by using more than one sound at a time, presented against different backgrounds. An analysis of the relevant, emerging acoustical correlates together with other descriptors is performed. A review of current auditory saliency models and the deficiencies of conventional testing approaches are provided. These motivate the development of our experimental test bed and more formalized stimulus selection criteria to support more versatile and ecologically relevant saliency models. Applications for auditory scene analysis and sound synthesis are briefly discussed. Some initial conclusions are drawn about the definition of an expanded feature set to be used for auditory saliency modeling and prediction in the context of natural, everyday sounds.
High pressure phase transitions in the fluid region surrounding the collapse point of large single bubbles in water
Authors: Sukovich Jonathan R. , Anderson Phillip , Sampathkumar Ashwinkumar , Holt R. Glynn
Published: May 2013

Observations from imaging experiments will be presented, which have shown persistent, long-lived spherical objects to form in the fluid region surrounding large, single bubbles in highly over-pressured water. Objects have been observed to form in a region of fluid where pressures are first predicted to exceed 0.8 GPa, and to extend radially inward to where fluid pressures are predicted to reach 6 GPa. These pressures bound those requisite for transitions in water to the crystalline phases of Ice-VI and Ice-VII, at 1.1 GPa and 2.1 GPa, respectively. The objects have been observed to behave in a fashion more consistent with a highly viscous fluid. They support and recover from large shape deformations, as well as support fluid flows within them. While water does have phases which are known to exhibit properties of highly viscous fluids, they have only been observed to form at or near cryogenic temperatures, typically via hyperquenching or quasi-static pressurization at low temperatures. Here, we present evidence for a high pressure liquid-liquid phase transition in water surrounding collapsing bubbles at room temperature. [Work supported by Impulse Devices, Inc.]
Percussoluminescence
Authors: Hawker Nicholas , Ventikos Yiannis
Published: May 2013

The phenomenon of light emission from a bubble driven to collapse via ultrasound has a long history of study. Light emission is widely believed to occur due to the formation of plasma within the bubble during the final moment of collapse and one important focus of the literature has been on understanding the exact thermodynamic conditions created. There are, however, other phenomena that demonstrate a similar light emission, including but not limited to other types of bubble collapse. This paper examines light emission in seeming disparate phenomena and discovers that a common thread exists. The terminology and fundamental theory appropriate for sonoluminescence is found to be decreasingly relevant and a new term, percussoluminescence (PCL), is established. This is substantiated through the presentation of a 1D theory, detailed numerical simulation, and illustrative experimental results. The implications of this new perspective are explored.
Investigating the acoustic response of gold nanoparticle coated microbubbles
Authors: Azmin Mehrdad , Rademeyer Paul , Mohamedi Graciela , Edirisinghe Mohan , Liz-Marzan Luis , Stride Eleanor
Published: May 2013

Recent work has shown that incorporating solid nanoparticles into the coatings of contrast agent microbubbles can be used to control their stability and to provide other functional characteristics for example in multimodality imaging. The aim of this study was to investigate the influence of nanoparticle characteristics and concentration on the response of the microbubbles to ultrasound excitation. Theoretical models were first derived to simulate the effects of adsorbing different types and concentrations of nanoparticle on to the surface of a bubble in both a monolayer and a layer of finite thickness. The results indicate that the particles modify the symmetry of the microbubble oscillations and enhance their nonlinear character. Experimentally, microbubbles coated with a surfactant and varying concentrations of gold nanoparticles of different sizes and surface properties were produced using either sonication or microfluidics. The attenuation and backscattering coefficients from the bubble suspensions and the scattered response from individual bubbles were measured for a range of frequencies (1–7.5 MHz) and pressures (50–500 kPa). The nanoparticles were found to enhance the nonlinear character of the bubble response in agreement with the theoretical results. Both the degree of enhancement and stability of the microbubbles was dependent upon the nanoparticle surface chemistry.
Investigating the sensitivity of microbubble acoustic response for biosensing applications
Authors: Harfield Caroline J. , Memoli Gianluca , Jones Philip , Ovenden Nick , Stride Eleanor
Published: May 2013

Microbubbles are currently used as contrast agents for diagnostic imaging on account of their high scattering efficiency and non-linear response to ultrasound. The exact nature of this response depends not only upon the bubble size and imposed sound field but also the bubble environment: physical properties of the surrounding liquid, bubble surface coating, ambient temperature, pressure, and proximity to other bubbles or surfaces. This dependence can potentially be exploited for the microscale interrogation of a liquid to detect, e.g., changes in viscosity or the presence of particular chemical species. To facilitate this, the sensitivity of the microbubble acoustic response to changes in its environment must be analyzed. The aim of this study was to provide a theoretical framework for this. A modified Rayleigh-Plesset equation was derived to describe the radial bubble motion, including the effects of gas diffusion and adsorption/desorption of a surfactant coating, and coupled to an equation describing microbubble translation. The presence of a rigid boundary was also included in the simulations. A sensitivity analysis was performed for the effect of each of the physical variables upon the bubble response, which indicated high sensitivity to species altering the dynamic surface tension and proximity to a boundary.
Acoustic and optical observations of methane gas seeps in the Gulf of Mexico
Authors: Weber Thomas C. , Rzhanov Yuri , Jerram Kevin , Mayer Larry , Lovalvo Dave
Published: May 2013

In 2011 and 2012, measurements of acoustic backscatter from natural methane seeps were made in the northern Gulf of Mexico in water depths between 1000 and 2000 m. The measurements were made using a calibrated 18 kHz echo sounder with an 11 degree beamwidth in order to estimate the depth-dependent target strength (TS). The TS data indicate a wide variation in the rate of gas seepage from the seafloor. Several of these seeps were revisited with a remotely operated vehicle in order to optically assess the bubble size distribution and to estimate the rate at which gas bubbles were exiting the seafloor. The optical data show bubble sizes between 1 and 10 mm radius, and similar rates of gas seepage ranging from a few bubbles per second to several tens of bubbles per second. Together, these data help to suggest the requirements for acoustically estimating gas flux from the seafloor over large regions.
Effect of shell thickness on sound propagation through encapsulated bubbles: A resonator approach
Authors: Dolder Craig N. , Wilson Preston S.
Published: May 2013

The acoustics of elastic-shelled bubbles are of interest in applications ranging from biomedical imaging, to fisheries acoustics, to underwater noise abatement. Multiple models exist to predict the velocity and attenuation of sound propagating through water containing encapsulated bubbles, but existing measurements have yet been able to confidently verify model accuracy for void fractions above about 10−3. The effect of shell thickness was studied in this work using tethered, rubber-encapsulated bubbles bearing shells of varying thickness, deployed within a one-dimensional resonator apparatus. In previous work, resonator modes below the individual bubble resonance frequency (IBRF) were exploited to extract inferences of sound speed, but this is a regime where there is little difference between competing model prediction. In the present work, an increased understanding of the modal field inside the resonator has extended this technique to just below IBRF and to well above IBRF, both regimes where model behavior diversifies, thus providing a new opportunity for model verification. Measurement-model comparisons will be shown for encapsulated bubbles with radii ranging from 13 mm to 30 mm, void fractions ranging from 8.4×10−4 to 1.1×10−2, and shell thicknesses ranging from 0.085 to 0.16 mm. [Work supported by the Office of Naval Research.]
Validation of three-dimensional strain tracking by volumetric ultrasound image correlation in a pubovisceral muscle model
Authors: Nagle Anna S. , Nageswaren Ashok R. , Haridas Balakrishna , Mast T. Douglas
Published: May 2013

Little is understood about the biomechanical changes leading to pelvic floor disorders such as stress urinary incontinence. In order to measure regional biomechanical properties of the pelvic floor muscles in vivo, a 3D strain tracking technique employing correlation of volumetric ultrasound images has been implemented. In this technique, local 3D displacements are determined as a function of applied stress and then converted to strain maps. To validate this approach, an in vitro model of the pubovisceral muscle, with a hemispherical indenter emulating the downward stress caused by intra-abdominal pressure, was constructed. Volumetric B-scan images were recorded as a function of indenter displacement while muscle strain was measured independently by a sonomicrometry system (Sonometrics). Local strains were computed by ultrasound image correlation and compared with sonomicrometry-measured strains to assess strain tracking accuracy. Image correlation by maximizing an exponential likelihood function was found more reliable than the Pearson correlation coefficient. Strain accuracy was dependent on sizes of the subvolumes used for image correlation, relative to characteristic speckle length scales of the images. Decorrelation of echo signals was mapped as a function of indenter displacement and local tissue orientation. Strain measurement accuracy was weakly related to local echo decorrelation.
Noise minimization in micromachined piezoelectric microphones
Authors: Littrell Robert , Grosh Karl
Published: May 2013

Piezoelectric MEMS microphones have been built for more than 30 years and they offer some advantages over other technologies such as improved linearity, simple construction, no need for a bias voltage or charge, and the ability to withstand high temperatures. Despite these advantages, a relatively high noise floor has always limited their utilization. Traditionally, the noise of these sensors has been minimized by viewing the pre-amplifier or amplifier as a black box with fixed gain and noise. This leads the designer to minimize noise by maximizing microphone sensitivity. By viewing the microphone-amplifier system together, we develop a different method of optimization, leading to lower noise. Further, by including the back cavity compliance of the package in the optimization, we can determine absolute limits on the minimum achievable noise floor with very few assumptions. To date, we have built piezoelectric MEMS microphones utilizing aluminum nitride with a 32 dBA noise floor. We can compute a minimum achievable noise floor of 24 dBA for the same sensing structure with a 2 mm3 back cavity volume.
The efficiency of receivers used in hearing aid devices
Authors: Salameh Michael
Published: May 2013

Current drain is one of the most important considerations in the hearing aid design. It is determined mainly by the receiver impedance. Recently, many additional features and technologies such as wireless are used in the hearing aid devices. These capabilities increase the current drain further. Efficiency evaluation becomes an important step in the receiver selection for hearing aid devices. Balanced armature receivers are widely used in hearing aids. In comparison with the moving-coil loudspeakers, these receivers are designed for better efficiency in closed acoustical loads found in different hearing aid styles. However, the receiver efficiency for hearing aid applications is not well defined, evaluated, or reported. In this paper, the receiver efficiency including the effect of the receiver size, impedance, and acoustical load is discussed. The evaluation of the receiver efficiency is revisited and a new approach is suggested. The simulation and the measurement results are presented.
Cantilever mode piston transducer array
Authors: Butler John , Butler Alexander L.
Published: May 2013

The underwater sound cantilever mode transducer uses a piston, tail mass, dual piezoelectric cantilever benders, and mechanical arms for translating lateral bending cantilever motion to piston motion in a direction normal to the cantilever motion. This compact design provides a wide band response and exceptionally low resonance, especially under array loaded conditions. We present the operation of the cantilever mode transducer along with its unique response under array loading conditions where the resonance frequency decreases as the array gets larger. These results are demonstrated through a number of finite element array models and measured results on a 2x2 array. The single crystal PIN-PMN-PT results show a significant source level improvement over ceramic PZT-8 active material when driven up to 5 V/mil.
Applications of network synthesis and zero-pole analysis in transducer modeling
Authors: Warren Daniel
Published: May 2013

When a transducer is an immutable component of a larger system being simulated, it is sufficient that the transducer model correctly reproduce behavior only at the available ports of the transducer. The behavior of two-port electroacoustic transducer should be completely characterized by three transfer functions related to the electrical and acoustic termination impedance and the transfer impedance. To the extent that the transducer could be represented as a analog circuit of passive linear elements, the same circuit could be exactly represented by rational polynomials of the Laplace s, embodied as a set of poles and zeros of the transfer functions. This invites the reverse process of identifying poles and zeros by nonlinear curve fit of rational polynomials to measured transfer data, perhaps even synthesizing a circuit directly from the identified poles and zeros. Measured transducer transfer data have been fit demonstrating both the utility and the pitfalls of this method. Curve fit transfer functions can be a compact and faithful representation of complex data over frequency, but have no predictive value outside the given data. Judicious selection of the number of poles and zeros, initial values, proper constraints, and some physical insight are necessary for stable curve fits. Further investigation into the relationship among the transfer functions of a physical system may lead to a meaningful model derived from curve fits.
Improved estimation of direction of arrival of sound sources for hearing aids using gyroscopic information
Authors: Boyd Alan W. , Whitmer William M. , Brimijoin W. Owen , Akeroyd Michael A.
Published: May 2013

Determining the direction of arrival (DOA) of a sound source is important in spatial audio signal processing, as it can lead to substantial improvement in noise reduction performance. Techniques such as generalized cross correlation with phase transform (GCC-PHAT) and adaptive eigenvalue decomposition (AED) perform optimally when the measurement microphones are fixed in place. However, hearing-aid microphones move with the listener’s head movements, which can result in momentarily inaccurate directional estimates and noise artifacts in the output signal. Techniques such as GCC-PHAT experience degraded short-term performance in the presence of multiple signals and noise. The system presented measures instantaneous head movement velocity using a micro-electromechanical systems (MEMS) gyroscope attached to binaurally communicating hearing aids. Estimates of DOA for physically stationary sources are shifted based on the gyroscope's head-movement information. Using GCC-PHAT with gyroscopic input can produce robust in situ DOA estimates for several sources in reverberant environments. In addition, the gyroscope allows an adaptive beamformer to be steered to a target direction, compensating for head movements on a very short timescale during DOA estimation. Results show improved localization performance over a standard GCC-PHAT system during head movements.
An escape guiding system utilizing the precedence effect for evacuation signal
Authors: Fujikawa Takahiro , Aoki Shigeaki
Published: May 2013

This research aims at building an escape guiding system using audio signals. The system utilizes the precedence effect for the listener to perceive easily the direction of an emergency exit. In one of the ordinary escape guiding systems, two or more loudspeakers are set on the ceiling of a passageway. Since the precedence effect is generated by delaying suitably the audio guidance signal radiated from the loudspeakers, the proper direction of the emergency exit is recognized. However, the effective listening area is limited. That is, the ordinary escape guiding systems is not effective in areas under loudspeakers. In this paper, a new method that the loudspeakers are set beside in a passageway is proposed. The generation and disappearance of the precedence effect of an audio signal in the new configuration are investigated. In the listening tests, the time delay and the difference of intensity between loudspeakers are parameters. The installation angle of the loudspeaker is another parameter. Male voice and female voices are used as emergency guidance. The guidance effect of the configuration in setting beside the loudspeaker is confirmed and the test results are discussed.
Vertical sound image control using level differences between parametric speakers
Authors: Maeda Kumi , Nishino Takanori , Naruse Hiroshi
Published: May 2013

Horizontal sound image can be controlled by using level difference between two loudspeakers; however, vertical sound localization is difficult. In this report, we propose a method of controlling a sound image with sound level differences between two parametric speakers that have a super-directivity. Our proposed system uses sounds that are reflected on a wall. In our experiments, two parametric speakers were arranged 56.6 and 226.0 cm high, respectively. Vertical sound localization was evaluated by subjective tests. Subjects were seven males and one female. Test signals were a white noise whose duration was 0.5 s. Sound level differences between parametric speakers were -∞, -9, -6, -3, 0, 3, 6, 9, and ∞ dB. Test signals were presented three times to each subject in a random order. Both parametric speakers were arranged at angles of 0°, ±5°, and ±10° from the horizontal plane, respectively. Answers were examined by the Wilcoxon rank-sum test. From the results, good performances were obtained when parametric speakers were arranged at angles of ±10°. [Work supported by a Grant-in-Aid for Scientific Research (24500203).]
Characteristics of whistle noise from mufflers with perforated pipes
Authors: Yamada Tatsuya , Seo Takehiko , Mikami Masato , Esaki Takashi
Published: May 2013

As a countermeasure to reduce exhaust gas pulsation noise in a wide frequency range, the exhaust system employs expansion, resonance and sound absorbing structures with perforated pipes. However, whistle noise is generated near holes under some conditions. In straight-through-type mufflers, sound absorbing materials covering punching holes can suppress whistle noise generation. On the other hand, in the expansion-cavity-type muffler, which has inlet and outlet insertion pipes, effective countermeasures have not been clarified yet. The purpose of this study is to improve understanding of whistle noise generation mechanism in mufflers with perforated pipes. First, we measured sound pressure of whistle noise radiating from a straight-through-type sub-muffler with a perforated pipe with steady flow. Results show that the frequency of predominant whistle noise became higher stepwisely with increasing the flow velocity and was higher with smaller hole diameter. Strouhal number based on the hole diameter, the frequency of predominant whistle noise and flow velocity existed within a certain range while the hole diameter and flow velocity were varied. Next, we measured the sound pressure of whistle noise radiating from an expansion-cavity-type main muffler with a perforated pipe. The whistle noise generation is discussed in comparison with that for the sub-muffler.
A design of an impedance tube for teaching acoustic material properties and laboratory techniques
Authors: Good Chelsea E. , Glean Aldo A. , Vignola Joseph F. , Judge John A. , Ryan Teresa J. , Bull Nicole , Turo Diego
Published: May 2013

The design and implementation of an adaptable acoustic impedance tube for instructional use will be presented. This system, which was designed for use in a graduate-level laboratory environment, is in accordance with ASTM standard E1050-98. The system is configurable for both horizontal and vertical measurements. Vertical use enables acoustic property measurement of granular materials, allowing characterization of a wide variety of media. The academic content is delivered by engaging students in measurements using the impedance tube. Specific acoustics content objectives include modeling of sound propagation in porous materials and the role of acoustic parameters such as porosity, tortuosity, and flow resistivity in quantifying acoustic behavior of materials. Instructional goals also include mastery of computer based data acquisition and processing. This aspect of modern laboratory practice is a critical part of our graduate acoustics curriculum. Students participated actively in the development of the software used to collect data and calibrate the impedance tube. The system design required the students to solve practical problems such as cutting and positioning of the sample as well as more demanding tasks such as design of a multilayer porous medium with desired acoustic properties.
The examination of the performance motion and emotional valence by a pianist
Authors: Mito Yuki , Kawakami Hiroshi , Miura Masanobu , Shinoda Yukitaka
Published: May 2013

Until now, we examined the performance motion by the snare drum. Particularly, we analyzed an association between emotion and motion using motion capture. We analyzed total of six emotions [tenderness, happiness, sadness, fear, anger, and non-emotion from Juslin (2001)]. The analysis method averaged the performance motion of six emotions. We named the method as “Motion Averaging Method (MAM).” We calculated the difference of the each emotion by the MAM and revealed the characteristic of motion. From the result, we achieved results in snare drum motion. Therefore, in this study, we considered the association between emotion and motion in the keyboard. The subject was a professional pianist. A musical piece was an etude of the music dictation. Motion capture system is the MAC 3D System of Motion Analysis Corp., which is an optical motion capture system. The measurement marker bonded 33 points to the upper body. As a result, we understood the difference in emotional valence by the center of gravity of the head, an arm, the body, and the hand. Particularly, the non-emotion was move less than other five emotions. Then, we were able to express an association between five emotions of Juslin and motion as a figure.
Overview of the waveform and sonicboom perception and response program
Authors: Page Juliet A.
Published: May 2013

The Waveform and Sonicboom Perception and Response (WSPR) Program conducted in California in November 2011 was designed to test and demonstrate the applicability and effectiveness of techniques to gather data relating human subjective response to multiple low-amplitude sonic booms. It was a practice session for future wider scale testing of communities, eventually using a purpose built low-boom demonstrator aircraft. The WSPR program addressed the following: design and development of an experimental design to expose people to low-amplitude sonic booms; development and implementation of methods for collecting acoustical measures of the sonic booms in the neighborhoods where people live; design and administration of social surveys to measure people’s reactions to sonic booms; and assessment of the effectiveness of various elements of the experimental design and execution to inform future, wider-scale testing. The low boom community response pilot experiment acquired sufficient data to assess and evaluate the effectiveness of the various physical and psychological data gathering techniques and analysis methods. Results include a comparison of survey modes, techniques for correlating subjective and objective data, assessment of single event and cumulative daily sonic boom subjective and percent highly annoyed results, and methods for analysis of empirical boom data.
Statistical analysis of community response to low amplitude sonic boom noise
Authors: Hodgdon Kathleen K. , Page Juliet , Gaugler Trent , Phillips Daisy , Shumway Durland , Rosenberger James
Published: May 2013

The Waveform and Sonicboom Perception and Response (WSPR) Program conducted a field study of subjective response to noise from multiple low-amplitude sonic booms. The team was led by Wyle and included researchers from Penn State, Tetra Tech and Gulfstream Aerospace Corp. The test exposed residents in the Edwards Air Force Base (EAFB) Housing area to two weeks of low-amplitude sonic booms while recording their responses via surveys. There were 52 participants divided across three response modes. The response instruments included Baseline Surveys, Single Event Surveys submitted each time a participant heard a boom, and Daily Surveys submitted at the end of each day. The analysis included assessments of single events and cumulative daily ratings of annoyance and categorical variables including loudness, interference, startle, vibration, and rattle. The WSPR daily annoyance data was analyzed by computing percent highly annoyed (%HA) and relating it to the cumulative noise exposure and by relating the subjective annoyance rating directly to the daily noise exposure. The WSPR design was established to cover the full range of noise exposures and annoyance factors so that sufficient data would be gathered to facilitate analyses of %HA and noise metrics. The statistical analyses examining these relationships will be presented.
Community response to low-amplitude sonic booms
Authors: Loubeau Alexandra
Published: May 2013

Sonic boom research conducted at NASA is oriented toward understanding the potential impact of sonic boom noise on communities from new low-boom supersonic aircraft designs. This research contributes to knowledge in key areas needed to support development of a new noise-based standard for supersonic aircraft certification. Partnerships with several industry, government, and academic institutions have enabled the execution of a pilot low boom community response test to develop and assess experimental methodologies, including sonic boom data acquisition, subjective data collection, and data analysis. Areas of additional research are identified and a prioritization of issues is performed to guide design of a potential follow-on pilot test. Lessons learned from these community response tests will facilitate future community testing with actual low-boom aircraft in communities not familiar with sonic booms.
The impact of including diffraction when predicting the effect of listener environment on the perceived loudness of outdoor sonic booms
Authors: Lind Amanda B. , Sparrow Victor
Published: May 2013

The human impact of sonic booms varies with listening environment. Given the incident sonic boom waveform, the specular field around a realistic geometry has been predicted via a C++ implementation of image source method (ISM) tailored to outdoor applications. This work explores the necessity of including the diffracted field when predicting time series and PLdB, both in and out of shadow zones. The impulsive nature of the excitation, and the sensitivity of the PLdB to temporal details, constrains appropriate diffraction modeling techniques to those capable of time domain accuracy. Uniform Theory of Diffraction (UTD) and Biot Tolstoy Medwin (BTM) approaches are considered. The benefits and challenges of each approach are explored, particularly with regards to scalability and bandwidth. The importance of accurately predicting diffraction in this application is evaluated through comparison with booms recorded around a building corresponding to the simulated geometry. [Work supported by the FAA/NASA/Transport Canada PARTNER Center Excellence and the Applied Research Laboratory. Experimental data courtesy of NASA.]
Soundscape workshop report: Perception Lexicon
Authors: Brooks Bennett M. , Schulte-Fortkamp Brigitte
Published: May 2013

A workshop was held at the 164th Meeting of the ASA in Kansas City on methodology standardization for the advancement of the developing field of soundscape measurement, analysis, and design. The workshop focused on the terminology lexicon used for soundscape subject interviews. Interviews of local experts, residents, and other users and inhabitants of the sonic environment can yield insights into both personal reactions and universal observations. The specific terminology used in this process may significantly affect the outcomes. As the success of a new research or development project can depend on the lessons learned from previous projects, the standardization of interview techniques becomes increasingly important. Workshop participants were invited to develop a standardized lexicon of descriptors for field use in interview questionnaires. After a review of soundscape objectives and procedures, the participants reviewed key issues and assessed available lexicon term types. The group then proposed, developed, and prioritized terms which could describe a soundscape as it is contextually perceived by an interview subject. Two key conditions were considered for each proposed lexicon term: would the term be commonly understood, and would the term describe a reaction to the soundscape of sufficiently notable intensity. The results of the workshop are presented.
Plan for research to better understand visitor response to the soundscape in national parks
Authors: Boyle James H. , Schomer Paul D.
Published: May 2013

Since 91% of national park visitors come to a park, at least in part, for the natural sounds, analysis of the perceptions visitors have of sound in national parks is extremely significant. In the summer of 2011, several pilot surveys were tested at Rocky Mountain National Park in Colorado for their abilities to provide an accurate reflection of visitors’ perceptions of the soundscape. The 2011 surveys were modified in various ways to create the current 2013 survey, which uses “pleasantness” of park sound as the main visitor response metric. The testing plan for the 2013 survey is non-labor intensive for respondents and researchers; rather than closely monitoring activities of respondents, and having them closely monitor the sounds they hear, this survey requires respondents to complete a short questionnaire every 30 to 60 min and an end-of-hike survey. Much like how day-night sound level (DNL) has traditionally been predicted for a cluster of houses around airports or highways, global sound measurements conducted along the trail will be correlated with visitor survey results in order to develop the means to predict how an average park visitor will respond to the soundscape.
When do we judge sounds? Relevant everyday situations for the estimation of ecological validity of indoor soundscape experiments
Authors: Steffens Jochen
Published: May 2013

This paper introduces a model of indoor soundscape evaluation, which is based on the results of listening experiments on household appliances. The model reveals, among other things, permanently changing action and attention processes and learning effects which occur in everyday settings. However, what are the relevant situations which we want to reconstruct in our experiments? When do people perceive and evaluate sounds in their everyday life like they do under test conditions? This theoretical knowledge is essential for the estimation of ecological validity of soundscape experiments in general. Hence, this contribution deals with approaches to determine meaningful real-life situations. The interviews held in the course of the studies show that many subjects construct extremely critical context situations while they are assessing sounds. These contexts are often not representative for these peoples' reality. Many participants, in fact, state that they no longer consciously perceive and evaluate the sounds of the appliances in their personal life. Decreasing attention over time can lead to a great influence of the first impression on subsequent perceptions and cognitions (primacy effect). Furthermore, the effect of memory processes on retrospective sound evaluations will be discussed.
Evaluation of noise climate in a campus environment using geospatial technology
Authors: Elangovan Rajasekar , YadavaMudaliar Pari , Rajan Venkateswaran , Anser Basha Khaleel Elur Rahaman , Muttavarapu Ravi
Published: May 2013

This study focuses on experimental evaluation of outdoor noise climate in an office campus, which is spread across 27 acres and investigation of its impact on the adjoining office buildings. For this purpose, a base map of the campus was prepared from the recent high spatial resolution satellite image using ESRI Arc/GIS and the same was used for planning appropriate locations for capturing noise levels and its spectral characteristics. Mapping grade Trimble GPS was used to stake out the measurement locations and noise levels were recorded using 01 dB solo and Norsonic type 118 sound level meters. Captured noise levels were plotted in GIS environment and appropriate spatial interpolation was carried out in order to give a continuous graphical representation of sound levels. A wide variation of noise levels was observed across the campus with LAeq ranging from 50 dB(A) to 80 dB(A). Low frequency noise was found to be predominant compared to mid and high frequency noise. Major noise sources and the propagation pattern were determined through the mapping. The data thus obtained is used to investigate the noise impact on the office buildings. The measurements were also accompanied by a subjective evaluation of the outdoor noise annoyance.
Experimental demonstration of a three-dimensional acoustic cloak based on a cancelation effect
Authors: Sanchez-Dehesa Jose , García-Chocano Victor M. , Climente Alfonso , Cervera Francisco , Gomez-Lozano Vicente , Sanchis Lorenzo , LLopis-Pontiveros Rafael , Juan Martínez-Pastor
Published: May 2013

A three-dimensional acoustic cloak has been designed, fabricated, and experimentally characterized. The cloak is made of 60 concentric tori acoustically rigid that surround a sphere of radius 4 cm, which is considered as the cloaked object. The major radii and positions of the tori along the symmetry axis are determined by a cancelation condition; i.e., the scattering cross section by the sphere and the tori must be zero. An optimization algorithm that combines a genetic algorithm and simulated annealing is employed to satisfy such a condition. The operational frequency of the one-directional cloak is 8.67 kHz with a bandwidth of about 120 Hz.
Ice thickness determination with audio sound
Authors: Shaw Anurupa , Declercq Nico F.
Published: May 2013

The objective of this study is to determine the thickness of Ice by analyzing the sound spectrum generated by dispersion of lamb waves propagating in ice. In winters when the lakes and rivers freeze, it is important to know the thickness of the ice layer before one intends to walk on it. When we throw a stone on the ice layer, we can hear a fluting noise. This is recorded for different thicknesses of ice and the sound spectrum is compared with the results simulated using a parameterized model. This model is created using a combination of plane waves for different incident angles and frequencies to generate dispersion curves for different thicknesses of ice. The frequencies of the reflected sound are then compared with the frequencies of musical notes in order to assign different musical notes to different thicknesses of ice.
Improving the usability of the distortion product otoacoustic emisssions-sweep method: An alternative artifact rejection and noise-floor estimation
Authors: Mauermann Manfred
Published: May 2013

The DPOAE-sweep method combined with a specific least-squares-fit (LSF) analysis provides a fast method to measure and analyze distortion product otoacoustic emissions (DPOAE) with a high frequency resolution. In studies using this technique the noise reduction, artifact rejection and noise estimation are typically realized in a “classical” way, i.e., as temporal averaging with preceding elimination of time epochs exceeding an artifact threshold level and a noise estimation based upon the analysis of the difference of two buffers of epoch averages. However, the choice of an artifact threshold is arbitrary to some extent and different choices can lead to differences in the estimation of DPOAE levels. The two-buffer technique is ambiguous as well since a different grouping of the epochs into the buffers leads to rather different noise estimates. Therefore, the present study proposes an alternative approach, which provides unique noise estimators for a given set of data, a robust artifact rejection without the need to select an arbitrary rejection threshold, as well as estimators including confidence intervals for the DPOAE levels and phases. The “classical” and suggested estimators for DPOAE levels, DPOAE phases, and noise levels are compared based on Monte Carlo simulations and real measured data sets.
Demonstration of distributed distortion-product otoacoustic emission components using onset-latency techniques
Authors: Lonsbury-Martin Brenda L. , Martin Glen K. , Stagner Bart B.
Published: May 2013

An oversimplified notion is that DPOAEs originate from a restricted region on the basilar membrane (BM). In actuality, DPOAEs are a distributed process involving the interaction of many wavelets, most likely generated over a broad region at, and basal to the overlap place of the primary tones. In the present study, DPOAEs were measured in rabbits as time waveforms by using phase rotation to cancel all components in the final average, except the 2f1-f2 DPOAE. At times, f2 was turned off for 6 ms producing a gap so that the DPOAE was no longer generated. These procedures allowed the DPOAE onset as well as the decay during the gap to be observed in the time domain. Results showed that complexities emerged near the onset of the DPOAE time waveform as the f2/f1 ratio decreased, and at the beginning of the gap when f2 was turned off. Such complexities were unaffected by interference tones (ITs) near the DPOAE. However, these complexities were removed by ITs presented above f2, which can be explained by the interactions of distributed DPOAE components with different phase relationships.