bluuebunny/crossref_metadata_2025 huggingface dataset:
Computer-aided B-mode ultrasound diagnosis of hepatic steatosis
Authors: Weijers Gert , Thijssen Johan , Wanten Geert , Drenth Joost , van der Graaf Marinette , de Korte Chris L.
Published: November 2016

A computer aided ultrasound (CAUS) protocol was developed for the diagnosis and staging of hepatic steatosis. Calibration of the fixed imaging preset enables expression of the US parameters relative to the tissue mimicking phantom used and consequently a vendor independent comparison. The CAUS protocol was validated on high yielding dairy cows (n = 151), which severed as a reference model for human non-alcoholic fatty liver disease. The study showed high values for: area under the curve (AROC): 0.94; sensitivity: 87%; specificity: 83%. A pilot study in patients on Home Parenteral Nutrition (HPN, n = 14) and a more extensive study in an obese cohort (n = 116) was performed. Validation was performed by Magnetic Resonance Spectroscopy (MRS). Both studies showed that of all parameters, the residual attenuation coefficient (RAC, the depth dependent mean echo level corrected for beam profile and normal attenuation in liver tissue) has the highest correlation to the reference (MRS fat percentage). For the HPN cohort, a correlation of 0.91 was found. In the obese population, this value was only 0.64; however, an AROC of 0.86, a sensitivity of 75%, and a specificity of 84% were obtained. In conclusion, CAUS shows promising results for non-invasive quantification of liver steatosis.
Controlling 3D sound field generated by a 2D surface from its 1D boundary
Authors: Qiu Xiaojun , Wang Shuping , Tao Jiancheng
Published: November 2016

As described by the Kirchhoff-Helmholtz integral equation, for a 3D space without internal sources, the inside sound field is completely determined by the sound pressure and its normal gradient on the boundary, so if only a portion of the boundary surface vibrates as the primary sound source while all the remaining portion of the surface is acoustically rigid, a sufficiently large number of secondary sound sources can be located evenly on the primary sound surface to control the 3D sound field completely. The question to be investigated in this research is whether it is possible to control the 3D sound field by only applying secondary sound sources along the 1D boundary of the 2D primary sound surface, for example, controlling the sound transmission from a door with secondary sound sources only on its frame. Simulation and experimental results will be presented to demonstrate the feasibility of the idea.
Analysis and synthesis of spatial sound fields with room response modeling using an integrated microphone and loudspeaker array system
Authors: Bai Mingsian R. , Li Yi , Chiang Yi-Hao
Published: November 2016

A unified framework is proposed for analysis and synthesis of spatial sound fields. In the sound field analysis (SFA) phase, an unbaffled 24-element circular microphone array (CMA) is utilized to “encode” the sound field based on the plane-wave decomposition, whereas in the sound field synthesis (SFS) phase a 32-element rectangular loudspeaker array is employed to “decode” the target sound field using pressure matching technique. Depending on the sparsity of the sound sources, the SFA stage can be implemented in two ways. For the sparse-source scenario, a two-stage algorithm is utilized to estimate the source bearings using the minimum power distortionless response (MPDR) and the associated amplitude coefficients of plane waves using the Tikhonov regularization (TIKR) algorithm. Alternatively, a one-stage algorithm based on compressive sensing (CS) algorithm can be used. For the nonsparse-source scenario, a one-stage TIKR is utilized to solve for the amplitude coefficients for plane-wave components uniformly distributed in the angular domain. The SFA technique for the non-sparse source scenario is also useful in establishing the room response model, as required in the pressure matching step of the SFS phase. The integrated acoustic array system is validated with localization and listening tests.
Sound field reproduction system with active reverberation
Authors: Omoto Akira
Published: November 2016

Sound field reproduction system can be categorized roughly into two types. The first is physically assured system which reproduce the wavefront or another physical parameters by engineering means. Typical examples are the boundary surface control system, the wave field synthesis, the ambisonics, and so on. The second type is a psychological system that reproduces phantom images one sound at any desired position by artificial manipulation with rather simple technique such as volume based amplitude panning. Examples are the two channel stereo system and the surround system using 5.1 or more loudspeakers. The latter can be recognized as somewhat “artistic” method, because it requires norms based on artistic sense. The present study aims to fuse the engineering and artistic systems mentioned above. The boundary surface control system, which consists of 24-channel narrow directional microphones and 24 channel loudspeakers, was used as the platform of research. Based on the conventional control technique using inverse filtering, additional manipulation such as simple reproduction scheme for high frequency was introduced. Also, the concept of variable reflection acoustic wall system, which adds the artificial reverberation to the sounds that listener makes, was involved in the reproduction system for the direction of the presence.
Interactive simulators for acoustic education
Authors: Suda Hiroshi
Published: November 2016

In the field of acoustic education, there are many complex theories and invisible phenomena. In the lecture of acoustics, the lecturer places much value on forming and expanding mathematical expressions, using textbooks and the blackboard. Students often have difficulty and want new teaching/learning methods and materials. New learning materials can help a student understand a phenomenon; for example, with a short movie describing an actual phenomenon or an environment of experiments using limited models. Now, the calculating power of computers, tablets and smartphones has enough to easily simulate acoustic phenomena. Here distributed web-based interactive simulators for acoustic education are presented.
Use of the student edition of ACTRAN in acoustics education
Authors: Sparrow Victor , Migeot Jean-Louis , Coyette Jean-Pierre
Published: November 2016

The power of computation has changed the way problems are solved in acoustics, and students should be trained to have an adequate background in modern techniques and software packages to simulate noise and vibration. Universities often cannot provide industrial-grade packages for their students due to the cost limitations. But recently a student version of a modern acoustics computation package was released, Student Edition of ACTRAN. This tool lets students solve a wide variety of problems using finite elements and infinite elements. This talk will describe the software and how it was used in a graduate level course in computational acoustics. Two examples that will be shown include finding the modes of an irregularly shaped room and computing the acoustic radiation from a gearbox. But it is clear that this software can be used in many different ways, for both undergraduate and graduate acoustics education. Instructors can demonstrate acoustical phenomena for students not adept at using the software themselves, easily visualizing the physics involved in acoustics with the Student Edition of ACTRAN. The software is free for downloading from http://www.mscsoftware.com/page/actran-student-edition.
An interactive speech synthesizer for acoustic education developed with pure data
Authors: Aoki Naofumi
Published: November 2016

Developing real-time sound systems that allow interactive controls requires advanced skills of sound programming. It often takes time even for experienced programmers to develop such systems. This paper shows an approach for rapid prototyping of such systems by using Pure Data. Especially, this paper focuses on the techniques of interactive controls by combining personal computers and some other peripheral devices such as a smart phone with Touch OSC. This paper describes its possibilities through showing demonstrations. As an example, this paper shows an interactive speech synthesizer. It allows users to control formants by pointing the F1-F2 diagram on the touch screen of a smart phone. Since this system allows time varying controls of the formants, it can synthesize semi-vowel sound as well as vowel sound. In addition, it also allows users to synthesize some other phrases by controlling appropriate movement of the formants by pointing the F1-F2 diagram. These experiences may potentially be effective for students who learn acoustics to be speech therapists. With this system, students can understand the mechanism of speech production in an experimental way. This paper mentions its availability for acoustics education.
Teaching Mathematica® based computer computations for support of laboratory experiments, special projects, and research for undergraduates taking acoustics and for mentorship students
Authors: Korman Murray S.
Published: November 2016

Undergraduate senior level physics majors taking Acoustics and oceanography majors taking Underwater Acoustics and Sonar learn how to use Mathematica® for doing standard laboratory experiments, special projects, solving homework problems requiring detailed computations or graphics. Students in electrical engineering, economics, mechanical engineering and ocean engineering (along with physics majors) have enrolled in a one credit course—Mathematica® 10 for Scientists and Techies. The feedback from students using a computer language in their course work for the first time is very encouraging and the teaching experience quite rewarding. High school mentorships volunteering to do research after school use Mathematica® for doing projects in the Physical Acoustics Laboratory. Some undergraduate lab projects involve Fourier analysis, measuring sound speed vs. temperature in water, and plotting theoretical and experimental Bessel mode shapes (or cosine shapes) for standing wave resonance in a cylindrical cavity. Here, a long slender tube mounted on the microphone probe translates along the radial or axial directions. Students enjoy generating their own data on a spectrum analyzer, transferring files to Mathematica® and plotting tuning curves vs. frequency in Helmholtz resonators. One student got involved in nonlinear drum vibration while another became interested in synthetic aperture imaging, for senior research projects.
The role of artificial speech in understanding the acoustic characteristics of spoken communication
Authors: Story Brad H.
Published: November 2016

Models have long been used to understand the relation of anatomical structure and articulatory movement to the acoustics and perception of speech. Realized as speech synthesizers or artificial talkers, such models simplify and emulate the speech production system. One type of simplification is to view speech production as a set of simultaneously imposed modulations of the airway system. Specifically, the vibratory motion of the vocal folds modulates the glottal airspace, while slower movements of the tongue, jaw, lips, and velum modulate the shape of the pharyngeal and oral cavities, and coupling to the nasal system. The precise timing of these modulations produces an acoustic wave from which listeners extract phonetic and talker-specific information. The first aim of the presentation will be to review two historical models of speech production that exemplify a system in which structure is modulated with movement to produce intelligible speech. The second aim is to describe theoretical aspects of a computational model that allows for simulation of speech based on precise spatio-temporal modulations of an airway structure. The result is a type of artificial talker that can be used to study various aspects of how sound is generated by a speaker and perceived by a listener.
Microphone array measurements of concert grand piano soundboards in different stages of production
Authors: Plath Niko , Pfeifle Florian , Koehn Christian , Bader Rolf
Published: November 2016

A series of measurements is taken on two concert grand pianos in seven different stages of production, starting with the glue-laminated soundboard planks and ending with the completely assembled piano in concert tuned state. Due to the large size of the soundboard as well as its irregular shape, measuring deflection shapes is a nontrivial task. Common measurement tools such as piezoelectric accelerometers can affect the acoustic vibrations of the soundboard due to the added mass. To this end, a noninvasive microphone array method is utilized for the present work. The array consists of 105 microphones successively placed parallel to the soundboard, resulting in a total number of 1289 microphones covering the entire surface. The Soundboard is excited using an acoustic vibrator at 15 positions associated with string termination points on the bass and main bridge. Impulse responses are obtained using the SineSweep technique. The measured sound pressure can be back-propagated to the radiating soundboard surface using a minimum energy method. Based on the measured vibrational and acoustical data a set of signal features is derived which cover direct physical behavior (e.g., driving point mobility, damping, radiation efficiency) as well as perceptive parameters (e.g. attack time, spectral centroid). The empirical findings will contribute to a software tool (based on a real time physical model) to help piano makers estimate the impact of design changes on the generated sound.
Analysis of piano performance using an eigenperformance
Authors: Miura Masanobu
Published: November 2016

Analysis of piano performance has been a great task for musicologists, in particular the “artistic deviation” on performance has been intensively discussed. Introduced here is a method to clarify what occurs on music performance by observing the eigenvector of obtained several piano playings, “Eigenperformance.” The eigenperformance is obtained for MIDI-piano playing from the tendency of onset, MIDI-velocity, duration, and instantaneous tempo curves. Eigenperformance is possible to indicate tendencies for a set of piano playing. By using eigenperformance, here investigates 1) the differences in evaluation criteria between pianists and non-pianists, and 2) the differences of deviations due to player’s skill. For 1), results of simple scale performance show that pianists evaluate short and sudden tempo changes with taking long time in ending notes along with dynamic and temporal expressions based on phrases on sheet music as good, whereas non-pianists never provide such evaluation. For 2), piano etude “For Elise” is dealt with to be investigated by four classes of proficiency. The eigenperformance revealed that the proficient performance shows same patterns of dynamics among first and second sections in sheet music, whereas the novice performance does not show any analogous on corresponding parts in sheet music.
The role of real-time acquisition of visual and auditory information in the performance of scale and arpeggio tasks in pianists
Authors: Ohsawa Chie , Sawai Ken-ichi , Tsuzaki Minoru
Published: November 2016

We previously found that the spatial memory of piano keyboard was not accurate enough to play without external spatial cues even in trained pianists. Therefore, the real-time acquisition of spatial information should be essential for piano performance. The aim of the present study was to test how and when the online acquisition of the visual and auditory information contribute to the performance of pianists. Seven undergraduate and graduate students majoring piano performance at a university participated in our experiment. They were asked to play the task sequences, which consisted of scale, arpeggio of triads, alternating fourth and fifth, and alternating fourth, fifth and one octave leap, on an electric piano. Each pianist played in four conditions: “Ordinary,” “No-sound,” “No-vision,” and “No-sound & No-vision.” The locations of the pressed keys were assigned to the locations of the keys to be pressed with dynamic programming after the midi note numbers were converted to the “location numbers.” We analysed the error size and the alignment costs. The results indicated that the visual information clearly contributed for touching accurate place in arpeggio tasks, while the contribution of the auditory information was limited in any task type.
Acoustical properties of the front-duplex system in a grand piano
Authors: Pfeifle Florian
Published: November 2016

The duplex scala, patented by Theodore Steinway in 1872, has been subject to several disputes since it found its first application in grand pianos. Not without good reason because, as was shown in the work of Öberg & Askenfeldt (2012), the physical effects explained in the patent can not be substantiated by measurements mainly because the tune of the duplex strings deviate considerably from the suggested theoretical values. Nonetheless, as published in the same work, the perceptual relevance of the rear- and more so of the front-duplex is stressed. As is shown there, even untrained musicians are able to perceive the influence of both duplex scalae. In this treatise, physical properties of front-duplex strings are considered and an explanation of the acoustical importance regarding the string vibration of the main string is given. To this end, a series of high-speed camera measurements of several duplex strings are presented. Due to the small deflection of front-duplex strings, the recorded data is processed using motion magnification methods showing the influence of different modes of vibration in different frequency bands. A physical model of a grand piano string chorus is proposed, aiding in characterizing the main influence of the front duplex string.
Three-dimensional computational fluid dynamics prediction of mild surge in a turbocharger compression system vs. experiments
Authors: Dehner Rick , Selamet Ahmet , Selamet Emel
Published: November 2016

The flow instabilities in a turbocharger compression system are studied numerically by employing a compressible, three-dimensional computational fluid dynamics code. The model represents the full compression system of a turbocharger test stand, consisting of a compressor inlet duct breathing from ambient, a centrifugal compressor, an exit duct connected to a plenum, followed by another duct which incorporates a valve restriction. The detailed compressor model includes the full rotating impeller and resolution of the clearance gap between the impeller blades and shroud. The simulation begins at a converged, stable operating point, where the flow rate at the outlet boundary is gradually reduced and maintained at the final value. Characteristics of mild surge are captured as the mass flow rate is reduced below the stability limit, including a discrete low frequency sound peak near the Helmholtz resonance of the compression system. The predictions are then compared with experimental results obtained from the turbocharger stand placed in a hemi-anechoic room. The computational results are shown to be capable of reproducing a number of key experimental observations, including the details of low-frequency pressure fluctuations in the compressor ducts and plenum, and the transition from stable operation to oscillating mild surge.
Numerical analysis of low frequency noise propagation from outdoor into house
Authors: Hashimoto Dai , Inoue Naohisa , Sakuma Tetsuya
Published: November 2016

There have been increasing environmental problems caused by low-frequency noise: window rattle, human annoyance and so on. Sound transmission from outdoor into a house in the low-frequency range is a considerably complex phenomenon because the house behaves as a total vibrating system composed of windows, walls, frames, ventilation holes, and so on. This paper presents a finite element model of a simple house in order to investigate the low-frequency sound transmission. The features of the model are as follows: 1) a rigid hollow cube with an aperture on its one side is placed on a rigid plane, 2) a windowpane mounted on the aperture is modeled as a limp membrane or an elastic plate, 3) the outdoor domain is truncated by perfectly matched layers in order to simulate a semi-free field, and 4) a noise source is supposed to be an air conditioning outdoor unit placed near the house. It is confirmed that the indoor SPL gains mainly due to two resonance systems: one is the global motion composed of indoor air tightness and mass around the aperture, and the other is the series of normal modes excited in a cubic room.
Influence on human body of audibility amplitude modulation low-frequency noise in residential environment
Authors: Matsuda Hiroshi , Machida Nobuo
Published: November 2016

Low-frequency noise of about 100 Hz including audible frequency is positioned as one of the factors of environmental problem. First, this paper describes countermeasures of psychological complaint by low-frequency noise generated by residential environment in Japan published in the Ministry of the Environment. Next, we experimentally examined the human body influence of audibility amplitude modulation low frequency noise (AMLFN) on the psychological and physiological response measured by whole-body exposure. The AMLFN used by this research fluctuated the fluctuation cycle of the carrier wave and the sound pressure level periodically by the amplitude modulation. The measuring objects of the psychological response are an annoyance by the psychological questionnaire and an impression evaluation by the semantic differential method. The measuring objects of the physiological response are a salivary amylase activity, a R-R interval, and a power spectrum of heart rate variability. The stress reaction by AMLFN exposure was examined from these measurement results. From these experimental results, the stress reactions during AMLFN exposure were tendency increased with an increase of the modulation depth of the sound pressure level and a decrease of the fluctuation cycle, and the annoyance was tendency increased with a decrease of the carrier frequency.
Low frequency sound sources, regulations, and the wind noise evaluation for appropriate procedure against complaints
Authors: Shimura Masayuki
Published: November 2016

There are many kinds of low frequency noise sources, including cannon, tunnel-blasts in construction, the Shinkansen, arch dams, elevated roads, wind farms, and so on. For example, low frequency noise by bombardment practice of the Ministry of Defense is dominant in the 8—16 Hz bands in the emission area nearby dwelling houses. Local regulations for soundproofing are applied in such cases. In the sound emission problems by drainage from the dam, we have to discuss the noise abatement of low frequency sound. However, there is neither existing regulation nor environmental assessment. Individual correspondence has been done for each noise source based on the complaints from dwellers. There are not unified countermeasures for low frequency sources in Japan. Evaluation of low frequency noise is very difficult because the measuring results are influenced by wind pressure fluctuation in natural wind. The physiological and psychological influence by such noise is also not clear. In this presentation, a new method to measure low frequency sound in natural wind is proposed.
Propagation of a finite-amplitude pulse in a bar of berea sandstone: The mechanisms of classical nonlinearity, conditioning, and hysteresis
Authors: Remillieux Marcel C. , Ten Cate James A. , Le Bas Pierre-Yves , Ulrich T. J.
Published: November 2016

We study the propagation of a finite-amplitude pulse in a slender bar of Berea sandstone. The center frequency of the pulse and aspect ratio of the bar are such that the problem can be adequately described by the propagation of a longitudinal wave in a 1D system. The evolution of the three Cartesian components of the particle velocity on the surface of the bar as functions of the propagation distance and source amplitude is carefully monitored without contact using a 3D laser Doppler vibrometer. In these experiments, we evidence simultaneously the effects from classical nonlinearity, hysteresis, and conditioning (i.e., elastic softening) in the impulsive waveforms, as the pulse propagates away from the source. Traditionally, this type of experiments has been conducted to quantify only classical nonlinearity, through the parameter β, based on the amplitude growth of the second harmonic as a function of the propagation distance. In this work, we also use these experiments to quantify conditioning, through the parameter of nonclassical nonlinearity α, based on the relative change in the arrival time of the pulse as a function of strain and distance from the source.
Simulation of coupled structural-acoustic response with dynamic damage evolution
Authors: Pitt Jonathan S.
Published: November 2016

A novel time-domain method for simulating dynamic damage evolution in a coupled structural-acoustic system is presented. The system is derived via the theory of continuum damage mechanics, and incorporates standard damage evolution models, but is readily extendible to more exotic formulations. The overall solution method is staggered, solving for the dynamic damage evolution first with an explicit step, and then using the new values in the coupled computation of the structural-acoustic system. The spatial domain is discretized using a mixed finite element method, and the temporal domain is discretized with a higher-order implicit time discretization scheme. Efforts toward fully coupled verification of the solution algorithm are presented, as are validation studies for cases without evolving damage. Applications with evolving damage are presented, and present a first principles study of changes in the structural acoustic response to dynamically evolving damage in the structure. Special attention is given to brittle fracture. Examples of downstream usage of the evolving structural response are discussed in the concluding remarks.
Fast and slow nonlinear elastic response of disparate rocks and the influence of moisture
Authors: Riviere Jacques , Shokouhi Parisa , Guyer Robert A. , Johnson Paul A.
Published: November 2016

We study nonlinear elastic phenomena in rocks at the laboratory scale, with the goal of characterizing and understanding observations at crustal scales, for instance, during strong ground motion and earthquake slip processes. A dynamic perturbation of microstrain amplitude in rocks results in a transient elastic softening followed by a log(t)-type relaxation back to the initial unperturbed elastic modulus as soon as the excitation is removed. Here we use Dynamic Acousto-Elastic Testing (DAET) to investigate the relaxation behavior over 7 orders of magnitude in time (from 10-4s to more than 103s). We find that relaxation starts for all samples between 10-3 and 10-2s. Some samples then exhibit a nearly perfect log(t)-relaxation, implying that no characteristic time can be extracted, while some other samples show a preferential relaxation around 0.1s/1s. Such features appear insensitive to the amplitude of the dynamic perturbation and to the moisture content within the sample. The full nonlinear elastic response (fast dynamics) is also extracted at all amplitudes and moisture content. Adsorption of water on the grains strongly increases the elastic softening during the dynamic perturbation and the non-classical nonlinear features, whereas the classical features seem rather unaffected.
Steady-state analysis of nonlinear ultrasonic waves caused by crack face friction
Authors: Maruyama Taizo , Touhei Terumi
Published: November 2016

In general, the detection of closed cracks is difficult by using the conventional linear ultrasonic testing. Therefore, the nonlinear ultrasonic testing (NLUT) based on the contact acoustic nonlinearity (CAN) is expected to be an effective technique for the problem. Several studies have reported the presence of nonlinear ultrasonic waves (higher- and sub-harmonic waves) due to the CAN. However, the theoretical explanation of the physical phenomena is not sufficient at present. For accurate NLUT, theoretical investigation of the nonlinear vibration phenomena of crack faces is desirable as a basic research. It is true that the time-domain analysis is becoming possible for the purpose. However, it is difficult to investigate in detail steady-state vibration of crack faces, which is supposed to affect behavior of nonlinear ultrasonic waves significantly. In this study, a novel numerical method is developed for the NLUT by coupling the boundary element method (BEM) and harmonic balance method (HBM) in order to investigate the above steady-state vibration. The scattering model is for the 2-D SH wave field that causes the crack face friction. Several numerical examples are presented in order to demonstrate validity and effectiveness of the proposed method.
Overturning of nonlinear shear waves in media with power-law attenuation
Authors: Cormack John M. , Hamilton Mark F.
Published: November 2016

Simple-wave solutions for nonlinear propagation predict waveforms that develop a vertical tangent at a finite propagation distance and subsequently become multivalued. Attenuation proportional to frequency raised to an exponent greater than unity counteracts nonlinearity sufficiently to prevent the waveform from overturning and becoming multivalued. If the exponent is between zero and unity the waveform may or may not overturn depending on the source amplitude. Multivalued waveforms indicate that the mathematical model lacks an appropriate loss term. The source amplitude above which waveform overturning occurs has been determined as a function of the power-law attenuation exponent for initially sinusoidal waveforms radiated into a medium with quadratic nonlinearity [Cormack and Hamilton, Proc. 22nd Int. Cong. Acoust. (2016)]. The analysis is applied here to nonlinear shear waves propagating in a medium with power-law attenuation using a modified Burgers equation with cubic nonlinearity and a loss term involving a fractional derivative. Introduction of intrinsic coordinates [Hammerton and Crighton, J. Fluid Mech. 252, 585 (1993)] permits numerical simulation of waveforms that become multivalued. The resulting evolution equation is used to determine the source amplitude above which an initially sinusoidal shear waveform will overturn. [Work supported by the ARL:UT McKinney Fellowship in Acoustics.]
Analysis of the effects on pronunciation of training by using song or native speech
Authors: Nemoto Saori , Wilson Ian , Perkins Jeremy
Published: November 2016

This research is an investigation of whether Japanese speakers’ English pronunciation improves more after training on sung or spoken speech. The stimulus was a 14-word sentence taken from one English song's lyrics, and it had some words that are difficult to pronounce for most Japanese English learners. Thirty Japanese learners of English were recorded before training. Then, half of them trained by listening to the English song and singing it, and the other half trained by listening to a native speaker speaking the lyrics. Each group was allowed to train individually for 10 minutes, and then were recorded again. Then, 15 native or near-native English speakers at an American university and 100 native English speakers from Amazon Mechanical Turk evaluated those randomly-presented recordings. Listeners gave points for various phrases’ pronunciation, the overall accent and the overall intonation. As a result, we found out that training by using the music condition resulted in generally worse results than the regular speech training. In addition, perhaps surprisingly, intonation of the whole sentence had an additional significant negative effect following music training. These results seem to show that training by using regular speech is more effective for English learners than training by using songs.
Characterization of very low frequency ambient noise by principal component analysis
Authors: Nichols Stephen M. , Bradley David L.
Published: November 2016

Long-term acoustic monitoring datasets compose a dynamic mixture of many source types, creating a unique noise field in each measurement location and for each recording time. Principal Component Analysis (PCA), and the correlation matrix from which the Principal Components are derived, offer an effective means of estimating the fundamental acoustic contributors, and their portion of the noise field. An improved characterization of ambient noise data sets is discussed, by representing the sound field in a smaller parameter space of principal components, each component reflecting the spectral characteristics of a specific sound source (i.e. fin whale vocalizations). This procedure leads to a definitive parsing of the contributing source types in the measured spectra. The datasets used are recordings from the Comprehensive Nuclear-Test Ban Treaty Organization’s (CTBTO) hydro-acoustic monitoring system.
Reconstruction of sound speed distributions from pulse-echo data
Authors: Podkowa Anthony , Hidayetoglu Mert , Yang Chunxia , Oelze Michael , Chew Weng C.
Published: November 2016

Ultrasonic imaging is perhaps the most ubiquitous form of biomedical imaging currently employed in the clinical setting due its safety, affordability, and real-time imaging capabilities. However, the poor image quality of standard brightness mode (B-Mode) images has inspired research into alternative acoustic imaging modalities, such as sound speed imaging. Historically, sound speed tomography has been employed in transmission-mode because of the limited k-space coverage available in backscattered data. However, such imaging techniques require specialized hardware configurations, and are often only limited to tissue such as the breast where full angular coverage is available. A recent approach [Jaeger et al., UMB, 41: 235-250, 2015] has demonstrated the feasibility of sound speed imaging using only pulse-echo data, which only requires a single array probe, commonly available in a clinical setting. This approach allows for complementary k-space coverage by utilizing relative temporal shifts between successive steered plane wave transmissions. Motivated by these successes, we present simulated and experimental pulse-echo sound speed reconstructions using three different methods: a modified Jaeger-like approach, the Born iterative method (BIM), and the distorted Born iterative method (DBIM).
Intracochlear sound sensor-electrode system for fully implantable cochlear implant
Authors: Zhao Chuming , Knisely Katherine E. , Colesa Deborah J. , Pfingst Bryan E. , Raphael Yehoash , Grosh Karl
Published: November 2016

We designed, fabricated, and tested an intracochlear sound sensor-electrode system consisting of an intracochlear sound sensor (ISS) and a 50μm Pt-Ir wire electrode. This system was designed to sense acoustic signals and transmit electrical stimuli inside the cochlea. Potential applications include acting as the front end of a fully implantable cochlear implant to treat sensorineural deafness or as a transducer in cochlear mechanics experiments. The ISS was comprised of an array of piezoelectric cantilevers and was built using micro-electrical-mechanical-system (MEMS) techniques. The ISS was tested in air and underwater to compare its functionalities to the numerical predictions. Later, the ISS was implanted in an anesthetized guinea pig and tested in vivo. A 90-100dB SPL pure tone acoustic excitation over 1-30kHz was delivered into the ear canal of the guinea pig, and 0.1-30μV was measured by the ISS. The sensed signal was linear, repeatable, and immune to the electrical interference from the extracochlear and intracochlear environment. When using the electrode, electrical auditory brainstem response (eABR) measurements were performed by sending a 25μs single pulse stimulus to the electrode. Stimulus amplitudes ranging in 220-400μA were found to evoke an eABR. These results show that the concept of sensing acoustic signals and transmitting electrical stimulation inside the living cochlea using one device is feasible.
Higher-order frequency locking of an organ pipe
Authors: Okada Masahiro , Kaburagi Tokihiko
Published: November 2016

To investigate frequency locking of an organ pipe, Abel et al. forced a sounding pipe with a pure tone (J. Acoust. Soc. Am. 119, 2467-2475, 2006). They showed that when the frequency of the pure tone approaches that of the pipe's fundamental, frequency locking can take place, whereby both frequencies are identical; that is, they are synchronized with a 1:1 frequency ratio. To gain a deeper understanding of organ pipes from the viewpoint of nonlinear oscillators, we searched for frequency locking at different ratios of the pure tone to the pipe's fundamental (pipe : pure tone = m:n). First, experiments were carried out for m:n = 1:2, 1:3, 2:1, and 2:3. We demonstrated that frequency locking occurs only if m = 1; that is, when the pure tone approaches the second or third harmonic of the pipe sound. We then analyzed our observations using synchronization theory, which describes frequency locking of a limit cycle oscillator. We found that m should be one when the external signal is a pure tone. The behavior of the organ pipe agrees well with that predicted according to synchronization theory; hence, the organ pipe can be treated as a nonlinear oscillator.
Sixteen types’ chord label estimation from acoustic signal of electric guitar
Authors: Yasui Nozomiko , Miura Masanobu
Published: November 2016

It’s difficult to determine an chord label for acoustical signal of musical playing, in particular when playing chords with “omitting”, “inversions,” or “tension voicing” on the guitar. Additionally, “enharmonic equivalence” produces multiple possibilities. This study developed a chord estimation system that deals with an audio signal output from electric guitars considering such techniques. All of the chord types employed in this study are the sixteen patterns frequently used in guitar chord playing. Chord labels are estimated by combination of salient pitch classes (or chroma), and some of them are dealt with as “performed notes” assumed as the member of played chord. Obtained performed notes are input to the “search tree for chord labels” so as to search possible chord labels, by referring chord progression patterns included in the “chord progression database.” Sixteen chord types are triad such as major, minor, aug, dim and sus4, with four-note chords such as 6th, 7th, Maj7, aug7, 7sus4, add9, min6, min7, minMaj7, min7(b5), and dim7. This study investigated appropriate threshold and type of filter used in the judgment of performed note. Results found that chord labels are estimated as 89% of accuracy when using three types of electric guitars.
On translating minimum siting distances into percentages of receiving properties meeting a stated dB(A) criterion
Authors: Schomer Paul D. , Pamidighantam Pranav K.
Published: November 2016

Around the world, minimum siting distances are used by regulators and developers to limit the effects of wind turbine noise on people. Acousticians know that the proper calculation is equal sound level contours, but customers, in this case the communities, developers, and regulators, all want simpler solutions. This study makes use of data collected at over 1200 dwelling units as a part of the Health Canada Study. This paper provides a method to determine minimum siting distances based on predicted percentages of exceedances of dB(A) criterion at dwellings.
Can inaudible and audible low level Infrasound and low frequency noise be an acoustic trigger of the startle reflex?
Authors: Cooper Steven E.
Published: November 2016

Modulation of audible low frequency ventilation fan noise reproduced in a laboratory has been shown to trigger the startle reflex in people sensitised to that noise. Using a range of low frequency and infrasound noise signals to sensitised and unsensitized subjects can show a causal relationship between an acoustic trigger and a physiological stress response, which engineers call “annoyance” or “noise annoyance” symptoms, and which biologists recognize as the “startle reflex.” Utilizing low level amplitude and frequency modulation as the source triggers a “startle reflex” response for comparison with the typical “startle reflex” to high level noise impulses.
Measures of sway as perceptual response to infrasound
Authors: Nelson Peggy B. , Sullivan Michael , Adams Meredith , Byrne Andrew
Published: November 2016

Some reports suggest possible negative human perceptual responses to infrasound and audible noise from wind turbines. Recordings were made in the field of turbine noise (audible and infrasound) at 300 meters. In our multisensory laboratory (Center for Applied and Translational Sensory Science at the University of Minnesota) we are re-creating these natural stimuli in a controlled environment. Infrasound stimuli were presented at approximately 85 dB SPL; audible stimuli were 55 dB SPL. Stimulus configurations were combinations of audible and infrasound emissions, testing the effects of these stimuli individually and in combination. We measured sway using an AMTI AccuSway Optimized force plate. Preliminary data suggest that measures of sway are stable and reproducible, and that some persons may show changes in stance in the presence of combinations of audible and infrasound stimuli. [Funding provided by Xcel Energy RD-14 to the University of Minnesota.]
Experimental study on noise radiation from wind turbines
Authors: Okada Yasuaki , Mizutani Yui , Yoshihisa Koichi , Iwase Teruo
Published: November 2016

Noise emitted from wind turbines is composed of aerodynamic and mechanical sound and has directional radiation characteristics. To investigate the horizontal sound directivity around a wind turbine under various wind conditions, field measurements of noise generated from two different wind turbines have been performed over long periods. Wind turbine operational data such as the nacelle direction and rotor rotational speed were collected at 1 s intervals along with corresponding acoustic data. An empirical formula for the directivity correction was derived from the A-weighted sound pressure levels measured at the several receiving points around the wind turbine. We also focused on the amplitude modulation components of wind turbine noise in emission areas and compared the estimated rotor speeds by using measured sound pressure levels with actual values. The results showed that the directivity pattern of the A-weighted sound pressure level for two different wind turbines is almost the same, whereas the frequency dependence of the sound directivity is different for the individual wind turbines. Additionally, the radiation characteristics of wind turbine noise depend strongly on the rotor rotational speed, which can be estimated from the blade-passing-frequency detected by using the amplitude modulation components of wind turbine noise.
Lateral impact noise isolation: motivation, methods, and mitigation
Authors: LoVerde John , Dong David W.
Published: November 2016

Impact noise isolation measurements and evaluation are traditionally defined and considered for vertical adjacencies exclusively, where the impact source is located in the space above the receiving room. ASTM E1007 has specific protocols, procedures and methods for the measurements and analysis of the data collected. However, impact noise transmission into the receiving room laterally adjacent to the source room (i.e., on the same floor) is important in some conditions (e.g., condominiums, apartments, and hotels). The existing standard provides no guidance for performing a lateral impact noise isolation measurement. The authors have developed methods and practices for performing this measurement. These are presented along with a selection of results demonstrating potential issues, criteria, and mitigation.
Difference in subjective magnitude between heavy-weight floor impact sources using auditory experiment
Authors: Ryu Jongkwan , Jeong Minju
Published: November 2016

Difference in subjective magnitude between heavy-weight floor impact sources was investigated using two auditory experiments. In the first experiment, subjective magnitude to various level (41~56 dB, L’i,Fmax,Aw) of heavy-weight floor impact sound by bang machine, impact ball and children’s jumping was investigated using rating scale method (7 points scale). And then, point of subjective equality (PSE) of floor impact sounds by bang, ball and children’s jumping was drawn using relative annoyance judgement method in second experiment. Stimuli were pairs consisting of the reference (fixed sound level in 50 dB, L’i,Fmax,Aw) and test stimulus (varied sound level), and the subjects rated the relative annoyance of test stimuli compared with a reference stimulus using a numerical scale (-3~0~ + 3). Results showed that floor impact sound level by bang machine was 3~4 dB lower than that of impact sound by impact ball in the PSE. It was also found that subjective magnitude of floor impact sound by ball was quite similar as impact sound by children jumping.
Acoustic resonances greatly improve detection of leaks from large pressure vessels
Authors: Gillis Keith A. , Moldover Michael R.
Published: November 2016

We measured the pressure p and the acoustic resonance frequency fa of argon gas in a 300 L tank. We then used the ratio p/fa2 (proportional to the mass M of gas) to determine the fractional leak rate (dM/dt)/M ≈ −13×10−6/hr of gas from the tank. The tank was filled with argon at 450 kPa and was exposed to sunshine-driven temperature and pressure fluctuations as large as (dT/dt)/T ≈ (dp/dt)/p ≈ 5×10-2 h-1 (i.e., 1000× larger) in a 24-hour record. This leak could not be detected in a 72-hour record of p/T. Theory predicts that the resonance frequencies are insensitive to linear temperature gradients; however, we do not have a detailed understanding of why the acoustic frequencies are insensitive to asymmetric, time-dependent heating of the tank. From auxiliary measurements and information from the literature, we believe that convective currents near the tank's walls carry most of the heat between the hot and cool regions, leaving a linear temperature gradient in the majority of the gas's volume. We plan to report preliminary measurements for a much larger (1800 L) tank. We expect that the results of this investigation will lead to effective acoustic methods for flow calibrations and leak detection in large volumes.
Effect of harmonic structure of notes on categorical chord perception
Authors: Utsugi Chiaki , Hamamura Mariko , Aikawa Kiyoaki
Published: November 2016

This paper reports distinct differences among the harmonic structures of notes on chord perception. Experimental results clarified that the existence of harmonics greatly improved chord perception accuracy. Subjective tests were conducted for 20 combinations of three notes from a minor chord to a major chord. The fundamental notes and the highest notes were fixed. The fundamental frequency of the middle note was shifted at an equal interval on the log scale. The harmonic structure was based on saw-tooth wave. The categorical perception accuracies were compared between pure tone and complex tone including five harmonics. The fundamental notes were C5 (523.3 Hz), A5 (880 Hz), and C7 (2093 Hz). The stimuli were diotically presented at 60 dB(SPL) through electro-static headphones. The subjects were requested to answer major or minor with the 2AFC method. The categorical perception accuracy was extremely low in case of C7 without harmonics. The percent corrects were as low as 46.7% and 54.8% for Cm and C, respectively. The Cm and C percent accuracies with harmonics were as high as 77.3% and 79.5%. The Cm and C accuracies were 97.7% and 93.2% for C5. The perceived categories turned from minor to major in the region between 8th and 15th note combinations.