bluuebunny/crossref_metadata_2025 huggingface dataset:
Sampling methods for uncertainty quantification in source localization and geoacoustic inversion in the ocean
Authors: Lin Tao , Michalopoulou Zoi-Heleni
Published: May 2013

Iterative and sequential Bayesian filtering approaches have been successfully employed for the estimation of select features of received acoustic signals—namely, arrival times and amplitudes of paths that have interacted with the propagation medium. These are subsequently utilized in source localization and environmental property estimation. Sequential filtering has the advantage of relating arrival times across spatially separated hydrophones of a receiving array, providing “tighter” estimates of arrival times and amplitudes and, thus, probability densities with a reduced “spread” in inversion. We demonstrate that sequential methods are superior to solely iterative ones by linking estimates of times and amplitudes to propagation models and estimating source location and environmental parameters. The inversion component of the problem is approached with an efficient approach, which relies on a novel implementation of linearization of the relationship that links parameters of the propagation medium to the received sound field. [Work supported by ONR].
Bayesian-based estimation of acoustic surface impedance: finite difference frequency domain approach
Authors: Bockman Alexander , Fackler Cameron , Xiang Ning
Published: May 2013

Design for acoustic performance in an interior fluid domain requires accurate description of boundary materials' specific acoustic impedance. The standard approach for the estimation of this material characteristic is the two-microphone, impedance-tube method. Modifications to the processing of the sampled acoustic field have been proposed to allow for more general test geometries. While analytical methods may be applied to a small class of ideal geometries, numerical methods provide greater geometric flexibility. In general, solutions to the wave equation forward problem are found from boundary element, finite element, or finite difference methods. The inverse problem of parameter estimation is solved by evaluating accuracy of prediction of the acoustic field for given distributions of the specific acoustic impedance parameter against observed data. In this presentation a Bayesian-network sampling approach is used to estimate specific acoustic impedance of a micro-perforated panel in an impedance tube test geometry. The choice of geometry and material allow for direct comparison to the two-microphone, impedance-tube method within the appropriate frequency range, and a theoretical model for the material beyond that frequency range. The potential to extend the frequency range of operation of the impedance tube is explored. Sensitivity of the method to nuisance parameters is discussed.
Identification of acoustic sources with uncertain data
Authors: Martin Vincent , Cohen-Tenoudji Frédéric
Published: May 2013

In inverse acoustic problems where attempting to identify the vibratory velocities of sources at the origin of an acoustic radiated field, we have the measured radiated field (called objective) on an antenna with numerous sensors and a propagation model. If both are erroneous, misidentification follows. Here, the problem is formulated in the frequency domain and solved in the least mean square sense. An impaired objective including an unstructured error has virtually no chance of satisfying the propagation equation. Accordingly, with an accurate radiation model, we cannot identify source velocities able to generating this objective. With the same model but now with unknown parameters (in the case of only one parameter it could be the speed of sound within the medium), it is expected intuitively that the parameter value aiming at the perturbed objective does not reach it but ultimately generates a pressure satisfying the wave equation, with a value near the correct pressure. The error in the model is structured in the sense that the model keeps a form satisfying the equations of physics. Currently, it is reported that this intuitive expectation is observed quantitatively through the geometric interpretation of over-determined inverse problems dealt with in L2.
A hierarchical mixture model for sparse broadband scattering functions between moving platforms
Authors: Gendron Paul J.
Published: May 2013

A hierarchical mixture model is considered for sparse broadband acoustic Green's functions [J. Acoust. Soc. Am. 130, 2346, Canadian Acoust. 40(3)]. Such a mixture model can be employed to match arbitrary second order statistics of a channel over time-bandwidth and angle. The model matches these statistics while simultaneously admitting the degree of sparsity necessary to capture propagation between moving platforms through the ocean waveguide. The uppermost stage of the hierarchy is specified by a mean bulk relative platform speed. Conditioned on this is a structured field of beta distributions associated with the probabilities of ensonified paths over beam-Doppler and frequency. The mixture model of the response is built from Bernoulli indicator variables whose probabilities are drawn from the field of betas. Posterior mean and variance are reviewed and used in an underwater acoustic receiver structure to replace Kalman like estimators of response as well as phase looked loop structures for symbol timing. The performance in terms of mean squared error is 10 dB lower than conventional Wiener filtering schemes when the channel response is significantly sparse. Reduction of this margin occurs as either sparsity or SNR is degraded. This degradation in performance is quantified under a range of sparsity constraints associated with the beta variates. [Work supported by the Naval Innovative Science and Engineering Program and the Office of Naval Research.]
Auralization of municipal public address announcements by applying geometrical sound simulation and multi-channel reproduction techniques
Authors: Mori Junichi , Yokoyama Sakae , Satoh Fumiaki , Tachibana Hideki
Published: May 2013

Municipal public address system (M.P.A. system) for disaster prevention is an important system for supplying information outdoors. The speech intelligibility of the M.P.A. system, however, tends to be deteriorated by long-pass-echoes due to reflections from the surrounding buildings and the sounds from the loudspeakers covering other sub-areas. When designing such a M.P.A. system, effective tools for prediction of outdoor sound propagation are needed. For this aim, the authors have been investigating the application of the sound simulation technique based on geometrical acoustics. In addition, auralization is also desirable to subjectively assess the speech intelligibility of the M.P.A. system in acoustical design. Therefore, the authors are developing a simulation technique in which the sounds calculated by the geometrical simulation are reproduced through a 6-channel reproduction system, by which 3D information can be aurally realized. In this paper, the outline of this simulation method and some examples of its application are presented.
Interoperability Building Information Modeling and acoustical analysis software—A demonstration of a performance hall design process
Authors: Kim Sunyoung , Coffeen Robert C. , Sanguinetti Paola
Published: May 2013

By sharing and managing the database for a building model, Building Information Modeling (BIM) facilitates the design process at less cost. Some of BIM software has capabilities for acoustical analysis, but it is limited to noise level demonstration of MEP system in a building. Sophisticated acoustical analysis programs, such as EASE and CATT, provide the useful parameters to determine the sound quality of a space with graphs, A/V systems, material database, and auralization. This research explores how BIM with discipline-specific data reinforced with acoustical information will be beneficial to both architects and acousticians, by allowing them to communicate efficiently. The design process for a performance hall is used to demonstrate how to interoperate between BIM system and acoustical analysis programs. Revit Architecture and EASE program are used as design and analysis tools for for the project. A model is developed to improve the process of embedding acoustic information in BIM and sharing knowledge in an integrated delivery process.
The system (software) for acoustic and lighting calculation (SCAL) program like support for acoustic and lighting conditioning in interior spaces
Authors: Garzón Beatriz S. , Coria Carlos R. , Manson Maria Josefina
Published: May 2013

This work aims to show an alternative software tool for calculating the acoustic and lighting conditioning and comfort in interior spaces. This program is developed in a desktop version and it can run on different operating systems because it is multiplatform. It is easy to operate. Program tools allow a quick calculation because the system values are stored standards of acoustics and lighting through an intuitive interface. The calculations can be stored and open for future modification; also, the results can be summarized and printed. The activities for its development and validation were as follows: (1) Survey on the requirements and interest that the system should contain. (2) Implementation of the program: It was conducted jointly between subject architecture specialists and computer engineers. (3) Development of training materials for the understanding of the functioning of the application. 4) Testing and evaluation period: The functional and non-functional requirements were evaluated and verify if the obtained results would be the expected results.
Energy decay analysis of non-diffuse sound fields in rectangular rooms
Authors: Sakuma Tetsuya , Eda Kazushi
Published: May 2013

Rectangular rooms with irregular aspect ratio or nonuniform absorption distribution apt to have non-diffuse sound fields, where the curvature of energy decay curve occurs in the reverberation process. In general, this curvature leads to longer reverberation times than the estimates by the Sabine or Eyring formula; however, it can be suppressed to a certain extent with diffusive wall surfaces. Recently, the author has proposed a new approximate theory of reverberation in rectangular rooms with specular and diffuse reflections. In this paper, the validity of the theory is investigated by two case studies with geometrical and wave-based acoustic simulation. In the first study, energy decay in a variety of rectangular rooms with changing the aspect ratio, the absorption distribution and the scattering coefficient, is simulated with the image source method and the ray tracing method. In the second study, a two-dimensional FDTD analysis is performed to demonstrate the frequency dependence of energy decay in a variety of rectangular rooms with flat or corrugated walls. Finally, the simulated results are compared with the theoretical ones, and the validity and the limitation of the approximation are discussed.
Evaluation of tumor cell death response in locally advanced breast cancer patients to chemotherapy treatment by scattering property estimates using ultrasound backscatter
Authors: Sannachi Lakshmanan , Tadayyon Hadi , Sadeghi-Nani Ali , Falou Omar , Jahedmotlagh Zahra , Oelze Michael , Czarnota Gregory
Published: May 2013

Breast cancer tumor response to chemotherapy in 29 patients was examined using quantitative ultrasound. Backscatter parameters, such as the average scatterer diameter (ASD) and average acoustic concentration (ACC), were estimated from regions-of-interest in tumors prior to treatment onset and at four times during neoadjuvant chemotherapy treatment (weeks 1, 4, 8, and prior to surgery). Gaussian and Anderson form factor models were used over an analysis bandwidth of 4 to 9 MHz to obtain ASD and ACC estimates. The Gaussian model did not fit with the measured data as well as Anderson model. Both ASD and ACC estimates yielded significant differences with therapy times in clinically treatment responded patients. Data indicated increases of approximately 3.5 µm in scatterer size and 6.6 dB/cm in acoustic concentration obtained maximum at week 8 in treatment responding tumors. Non-responding tumors did not show any significant difference in both the parameters. This study demonstrates that the scattering parameters have the potential to being used in quantifying the changes in tumors during treatment noninvasively and distinguishing treatment responders and non-responders.
Ultrasonic assessment of the in vitro biomechanical stability of a dental implant
Authors: Vayron Romain , Karasinski Patrick , Loriot Domitille , Haiat Guillaume
Published: May 2013

Dental implants are widely used for oral rehabilitation. However, there remain risks of failure, which are difficult to anticipate. The objective is to investigate the potentiality of a quantitative ultrasound method to assess the biomechanical stability of a dental implant in vitro. Two experimental configurations were considered using a 10 MHz contact transducer located at the implant extremity. For each ultrasound measurement, a quantitative indicator I is derived based on the time variation of the amplitude of the rf signal. First, seven implants were embedded in tricalcium silicate-based cement. One implant was left without any mechanical solicitation and six implants were subjected to mechanical stresses during 24 h. The ultrasonic response of each implant was measured during 24 h. The results show no variation of I without mechanical solicitation, while I significantly increases as a function of fatigue time. Second, 10 implants were unscrewed from bone tissue and their ultrasonic response was measured after each turn. Analysis of variance tests revealed a significant effect of the amount of bone in contact with the implant on the distribution of I. The results show the feasibility of our QUS device to assess the biomechanical quality of the interface surrounding the implant.
Superresolution imaging in ultrasound B-scan imaging
Authors: Parker Kevin J.
Published: May 2013

A number of imaging systems exhibit speckle, which is caused by the interaction of a coherent pulse reflecting off of random reflectors. The limitations of these systems are quite serious since the speckle phenomenon creates a pattern of nulls and peaks from subresolvable scatterers or targets that are difficult to interpret. Another limitation of these pulse-echo imaging systems is that their resolution is dependent on the full spatial extent of the propagating pulse, usually several wavelengths in the axial or propagating dimension and typically longer in the transverse direction. This limits the spatial resolution to many multiples of the wavelength. This paper focuses on the particular case of ultrasound B-scan imaging and develop an inverse filter solution that eliminates both the speckle phenomenon, and the poor resolution dependency on the pulse length and width, to produce SURUS (super-resolution ultrasound) images. The key to the inverse filter is the creation of pulse shapes that have stable inverses. This is derived by use of the standard Z-transform and related properties. Although the focus of this paper is on examples from ultrasound imaging systems, the results are applicable to other pulse-echo imaging systems that also can exhibit speckle statistics.
Acoustical absorption by materials in a nacelle of turbojet
Authors: Carlos Ibanez R. , Raymond Panneton
Published: May 2013

The paper discusses the absorption of certain materials with different acoustic properties used in a nacelle of aircraft is investigated using numerical model. A model 2-D with the configuration of axisymmetrical and the differential equations of the Continuity and Helmholtz equation is realized, it couples a finite element description with a boundary conditions a rigid wall, impedance and a frequency range (low–high) in order to evaluate three treatments ( resonator, foam, and the combination of both of materials) and his frequency behavior. Experimental results are presented to validate the model in the special case of insertion loss and the coefficient of sound absorption.
An acoustic study of ceramic traditional whistles
Authors: Gibiat Vincent , Le Gonidec Marie-Barbara
Published: May 2013

Ceramic whistles are very common all along the old European traditions. Gifts, jars, or simple decorative objects these whistles may have extremely various shapes: animals, jars, pitchers and sometimes flutes. Even with this extremely variability, their interior shapes are very similar: a channel where to blow, an edge, and a small cavity. Some of them produce a single sound when others present one or more tone holes, the latter corresponding mainly to flute shaped whistles. Their acoustic behavior appears to be very simple: Helmholtz resonators or flutes driven by the common non linear excitation system. Nevertheless some are known as water whistles and sometimes as “nightingales.” The acoustic study presented will first verify that the simplest whistles are really working as Helmholtz resonator with the noticeable exception of the flute shaped ones that remain whistles for the organologist but are a different object for the acoustician. Then, a particular attention will be given to the “nightingales” ones. Their sound production will be related to the level of water they contain and the modulation of the acoustic signal analyzed in terms of coupling between the oscillation of the water and the Helmholtz acoustic resonance.
Sound analysis and synthesis of Marquis Yi of Zeng’s chime-bell set
Authors: Wu Chih-Wei , Huang Chih-Fang , Liu Yi-Wen
Published: May 2013

In this paper, the analysis and synthesis results from a complete set of Chinese chime-bells (also known as Chinese two tone bells) are presented. Consisting of 65 bells with different sizes and tones, Marquis Yi of Zeng’s set is an ancient musical instrument with fascinating acoustical features but scarcely appears in current music performances for being huge and inaccessible. To preserve this cultural legacy in digital form, sounds of a complete set of replicated Marquis Yi of Zeng’s chime-bells were recorded and analyzed, and the pitch discrimination of fundamental frequencies between this replica and the original set has been evaluated. Sound synthesis models of chime-bells were constructed using multiple inharmonic digital waveguides, creating chime-bell like sounds. Quality of synthetic sounds was evaluated using both objective and subjective measures. Objectively, the similarity between synthetic and recorded sounds was compared in both the spectral and the temporal domains. The subjective measure was achieved through listening tests. Results show that sounds from different bells on the rack could be successfully generated from the proposed models, leading toward the realization of virtual chime-bell set in the future.
A digital library to advance interdisciplinary research in singing
Authors: Cohen Annabel J. , Fujinaga Ichiro , Lefford Nyssim , Leonard Theresa , Tzanatakis George , Vincent Coralie
Published: May 2013

In 2008, at the ASA/EAA symposium honouring pioneering scientist of singing, Johan Sundberg, the Advancing Interdisciplinary Research in Singing (AIRS) project was introduced as a major collaborative research initiative on singing [Cohen, Acoustics 08, Paris (2008), 3177–3182]. Over 70 collaborators around the world were to investigate singing from perspectives of development, education, and well-being. A digital library was to facilitate distant team members’ work on the same data, such as examples from voice studios around the world, performance stages, playgrounds, public places, solos, groups, classrooms, intergenerational or multicultural choirs, therapeutic settings or new tests of singing skills [Vincent et al. PEVOC9 (2011)]. Plans also included tools for annotation and analysis along with relevant documents and images. The present progress report on this endeavor describes preliminary prototypes, stages of development, and the current functional implementation. It is noted that although singing is primarily an acoustic and auditory phenomenon, video records of the singer are highly valuable. Their benefit, however, must be weighed against challenges arising from ethical considerations and storage requirements. Issues of ownership and data sharing are also raised as are practical matters of choice of platform, storage, formats, backup, human resources, and long-term preservation.
Acoustic differences in the speaking and singing voice
Authors: Livingstone Steven R. , Peck Katlyn , Russo Frank A.
Published: May 2013

Speech and song are universal forms of vocal expression that reflect distinct channels of communication. While these two forms of expression share a common means of sound production, differences in the acoustic properties of speech and song have not received significant attention. Here, we present evidence of acoustic differences in the speaking and singing voice. Twenty-four actors were recorded while speaking and singing different statements with five emotions, two emotional intensities, and two repetitions. Acoustic differences of speech and song were reported in several acoustic parameters, including vocal loudness, spectral properties, and vocal quality. Interestingly, emotion was conveyed similarly in many acoustic features across speech and song. These results demonstrate the entwined nature of speech and song, and provide evidence in support of the shared emergence of speech and song as a form of early proto-language. These recordings form part of our new Ryerson Audio-Visual Database of Emotional Speech and Song (RAVDESS) that will be freely released in 2013.
The Internet of sound observatories
Authors: Botteldooren Dick , Van Renterghem Timothy , Oldoni Damiano , Dauwe Samuel , Dekoninck Luc , Thomas Pieter , Wei Weigang , Boes Michiel , Muthuraman Ramanan , De Coensel Bert , De Baets Bernard , Dhoedt Bart
Published: May 2013

With the advance of electronics, sound level meters have become more powerful when it comes to analyzing and storing huge amount of measurements. In recent years, these devices have been hooked up to the internet and stream life data. In the IDEA project, the whole concept of a sound observatory is turned upside down by stripping the sensor nodes to their bare essential, and by migrating all logic and data storage to computing centers. This opens new opportunities in particular for long-term environmental sound monitoring and analysis. As unlimited computing power is available, more advanced analysis such as auditory scene analysis can be incorporated. In addition, new analysis methods and indicators can be deployed on the whole network of sound observatories using up-to-date software agent technology. As each observatory is a cheap plug-and-measure device without any buttons or display, participatory sensing becomes easy: citizens plug in their device and data streams to central servers and is displayed on a website of choice for the community. During the presentation, application cases in urban tranquil area, building site noise, wind turbine noise, and train noise monitoring, as well as noise mapping validation will be shown.
The modeling and calculation of sound radiation from facilities with gas flowed pipes
Authors: Probst Fabian
Published: May 2013

Computer modeling of industrial facilities like chemical plants, refineries, or other production areas is the first and most important step in the calculation of sound exposure in the environment. The pipework with gas flows is often contributing relevant to the sound radiation of the complete facility. This radiation can be determined applying the methods described in technical papers like VDI 3733 and ISO 15664. On the basis of these descriptions a software tool was developed that allows to create pipework in 3D models with line sources and to calculate the sound propagation with methods like ISO 9613-2. The line sources are linked with the technical parameters like pipe cross section, flow rate, pressure, density, and temperature of the gas and material parameters of the pipe wall. The sound power emission from the pipe to the environment and the internal flow of sound power—linked to the next section of piping—is calculated on the basis of these parameters. The same technique is used to calculate the sound emission of cooling towers, electric and fuel driven motors, gears pumps, and other devices. This powerful technique allows creating sustainable models that can be adapted to different operation conditions with minimum time and effort.
Sonofragmentation of molecular crystals
Authors: Suslick Kenneth , Zieger Brad W.
Published: May 2013

Developing processes for the production of active pharmaceutical ingredients (APIs) with a specific crystal size or polymorph distribution is critical for improved drug delivery by aerosolization, injection or ingestion, for control of bioavailability, and for economy of preparation. The use of ultrasound for the crystallization of APIs has attracted substantial recent attention due to (1) its influence on particle size and size distribution, (2) reduction of metastable zone-width, induction time, and supersaturation levels required for nucleation, (3) improved reproducibility of crystallization, (4) control of polymorphism, and (5) reduction or elimination of the need for seed crystals or other foreign materials. Possible mechanisms for the breakage of molecular crystals under high-intensity ultrasound were investigated, using acetylsalicylic acid (aspirin) crystals as a model compound for active pharmaceutical ingredients (APIs). Surprisingly, kinetics experiments rule out particle-particle collisions as a viable mechanism for sonofragmentation. Two other possible mechanisms — particle-horn or particle-wall collisions — were dismissed based on decoupling experiments. Direct particleshockwave interactions are therefore indicated as the primary mechanism of sonofragmentation of molecular crystals.
The influence of ultrasound on the structure, rheological properties, and degradation path of citrus pectin
Authors: Liu Donghong , Zhang Lifeng
Published: May 2013

The effects of ultrasound on the molecular weight, structure, and rheological properties of citrus pectin were investigated. The degradation path of citrus pectin by ultrasound was also studied. The structure and rheological properties of the degradation products were identified by high performance liquid chromatography-photodiode array detector (HPLC-PAD), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), atomic force microscope (AFM), and rheometer. The results indicated that the average molecular weight of citrus pectin decreased rapidly after ultrasound treatment and reduced to one third of the initial pectin after treated for 90 min. The polydispersity reduced from 2.30 to 1.59. The degradation products had a uniform and narrow distribution of molecular weight. The main chain composition and monosaccharide constituents of citrus pectin remained unchanged after ultrasound treatment. The reduction ratio of (Gal+Ara): Rha suggested a decrease in neutral sugar side chain size of citrus pectin after ultrasonication. FT-IR and NMR results approved that the main chain of citrus pectin was not changed by ultrasound treatment. Together with the AFM results indicated that ultrasound could reduce the branched structure of citrus pectin. The viscosity of citrus pectin decreased after ultrasound treatment. Meanwhile, the ultrasound-treated citrus pectin showed predominantly viscous responses (G′ < G″) over the same frequency range.
Effects of frequency and initial concentration of methylene blue on rate constants of ultrasonic degradation
Authors: Honma Chiemi , Kobayashi Daisuke , Matsumoto Hideyuki , Takahashi Tomoki , Kuroda Chiaki , Otake Katsuto , Shono Atsushi
Published: May 2013

Ultrasound has been found to be an attractive advanced technology for the degradation of hazardous organic compounds in water. The ultrasonic degradation of dyes has been investigated by many researches, but the effects of ultrasonic frequency on degradation rate were not investigated quantitatively. In our previous study, we proposed a simple model for estimating the apparent degradation rate constant of methylene blue based on ultrasonic power and the SE value in the range of frequency between 20 and 500 kHz. However, we have not investigated the ultrasonic degradation of methylene blue in high frequency region around 1 MHz. The effects of initial concentration of methylene blue have not been investigated yet, either. In this study, the degradation process using methylene blue as model hazardous organic compounds by ultrasonic irradiation was investigated. The ultrasonic frequency was operated in the range from 20 kHz to 1.6 MHz, and the initial concentration of methylene blue was in the range from 0.005 to 0.04 mM. Our proposed model can apply to this study which extended the frequency range. The effects of initial concentration can also be estimated in the range of 0.01 to 0.04 mM using this model.
Effect of gases on radical production rates during single-bubble cavitation
Authors: Hatanaka Shin-ichi
Published: May 2013

The yields of hydroxyl radicals and nitrite ions produced from single-bubble cavitation were quantified while the corresponding dynamics of the single bubble was observed by stroboscopic and laser-light scattering methods. The numbers of both hydroxyl radicals and nitrite ions per cycle were proportional to pressure amplitude at 25 kHz under the conditions of stable sonoluminescing single-bubbles. Under the dancing single-bubbles without sonoluminescence below sonoluminescence threshold for air bubbles, however, the number of hydroxyl radicals was larger than that for the stable single-bubble and nitrite ions were not detected in contrast to hydroxyl radicals. For argon bubbles, the numbers of hydroxyl radicals were larger than those for air bubbles and the number of hydroxyl radical was significantly increased with the dancing bubble by argon bubbling. The results imply that the shape instability may promote the dissolution and the diffusion of hydroxyl radicals from the bubble into the liquid and the part of hydroxyl radicals may convert into nitrite ions in the case of the air bubble above the threshold of sonoluminescence.
Loudness of complex time-varying sounds – A challenge for current Loudness models
Authors: Rennies Jan , Verhey Jesko L. , Appell Jens E. , Kollmeier Birger
Published: May 2013

The calculation of perceived loudness is an important factor in many applications such as the assessment of noise emissions. Generally, loudness of stationary sounds can be accurately predicted by existing models. For sounds with time-varying characteristics, however, there are still discrepancies between experimental data and model predictions, even with the most recent loudness models. This contribution presents a series of experiments in which loudness was measured in normal-hearing subjects with different types of realistic signals using an adaptive loudness matching procedure and categorical loudness scaling. The results of both methods indicate that loudness of speech-like signals is largely determined by the long-term spectrum, while other speech-related properties (particularly temporal modulations) play only a minor role. Loudness of speech appears to be quite robust towards even severe signal modifications, as long as the long-term spectrum is similar. In contrast, loudness of technical, strongly impulsive signals is considerably influenced by temporal modulations. For some of the signals, loudness could not be predicted by current models. Since the perceived loudness was underestimated by the models for some signals, but overestimated for other signals, a simple adjustment of the employed time constants in the temporal integration stage could not eliminate the discrepancies.
Comparison of detection threshold measurements and modeling for approaching electric cars and conventional cars presented in traffic and pink noise
Authors: Grosse Julian , Weber Reinhard , van de Par Steven
Published: May 2013

This study investigates the difference in audibility of an approaching conventional car with internal combustion engine and an electric car at various velocities. The goal was to compare the risk that pedestrians do not hear the approaching car in time. Binaural recordings of each of these approaching cars were presented together with either a traffic noise masker or a pink noise masker. In the first detection experiment, the threshold level was determined for which the cars could just be detected. In a second reaction time experiment, the moment was determined at which the approaching car was first detectable. This measured reaction time should give an indication about how much time a person has to evade an impending collision. Results indicated that slowly approaching electric cars where less audible than cars with a conventional engine. The results also showed that the decrement of reaction times as a function of SNR was halved when pink noise was used instead of traffic noise. A psycho-acoustic masking model [Dau et al., J. Acoust. Soc. Am. 99, 3615–3622 (1996)] was applied to predict detection thresholds and showed good correspondence with the subjective data.
Ultrasonic transducers with directional converters of vibration of longitudinal-longitudinal type and longitudinal-longitudinal-longitudinal type intended to work in gaseous media
Authors: Gudra Tadeusz , Palasz Lukasz , Opielinski Krzysztof J.
Published: May 2013

The study presents a realized concept of an ultrasonic transducer intended to work in a gaseous medium, which radiates a focused ultrasonic beam in many directions simultaneously. The use of a longitudinal-longitudinal (L-L) type vibration direction converter makes it possible to radiate ultrasonic energy in a required direction without changing the location of the activation source. The transducer consists of four resonant elements: an ultrasonic sandwich type transducer, vibration amplitude transformer, L-L type converter, and axisymmetrical radiating plates. It is also acceptable to use a longitudinal-longitudinal-longitudinal (L-L-L) type vibration direction converter. The benefit of such a solution is that it is possible to use one ultrasound source for simultaneous activation of several radiating plates. The study presents conductance and susceptance characteristics of a complex resonance system, amplitude frequency characteristics of the level of acoustic pressure and sample characteristics of the directivity of a transducer with two independent radiating plates. The suggested solution creates new possibilities for applications of this type of resonance systems.
Modeling incomplete glottal closure due to a posterior glottal opening and its effects on the dynamics of the vocal folds
Authors: Zañartu Matías , Erath Byron D. , Peterson Sean D. , Hillman Robert E. , Wodicka George R.
Published: May 2013

Even though incomplete glottal closure is present in normal and pathological voices, it has received little attention in self-sustained models of phonation. The effects of acoustic interaction due to a posterior glottal gap on the tissue dynamics, energy transfer, and glottal aerodynamics were numerically investigated. The domain was prescribed as flow through two separate orifices (posterior gap and membranous vocal folds) that merge in the supraglottal tract, with the governing flow equations determined from a control volume analysis based on conservation of mass and linear momentum. The equations of motion remained unaffected, although the driving forces were indirectly altered through the acoustic interaction. The method was implemented using the body-cover model, wave-reflection-analog sound propagation, and a boundary-layer asymmetric flow solver. The inclusion of a gap area of 0.03 cm2 reduced the RMS energy transfer from the fluid to the vocal folds by 20 % and radiated SPL by 5 dB. When compensating for this reduction with an increased subglottal pressure to match the same SPL, a significant increase in MFDR and AC flow was noted, thus mimicking vocal hyperfunction. In addition, larger gap areas yielded less glottal pulse skewing and a glottal airflow proportional to the transglottal pressure drop.
Liquid dynamics in a self-oscillating poroelastic model of the vocal fold
Authors: Tao Chao , Jiang Jack J. , Liu Xiaojun
Published: May 2013

The vocal fold tissue is considered as the composite of a porous elastic frame (composed of specialized proteins, carbohydrates, lipids, collagen fibers, and elastin fibers) filled with liquid. The properties of tissue are codetermined by the porous solid, the fluid, and their interaction. The poroelastic description of the vocal fold tissue could improve our knowledge about the mechanical properties and microstructures of these biological tissues. In this study, a self-oscillating poroelastic model is proposed to study the liquid dynamics in the vibrating vocal folds, where the vocal-fold tissue is treated as a transversally isotropic fluid-saturated porous material. Rich liquid dynamics have been found in this model. In the vertical direction, the liquid is transported from the inferior side to the superior side due to the propagation of the mucosal wave. In the longitudinal direction, the liquid is accumulated at the anterior-posterior midpoint. However, the strong collision between two vocal folds forces the accumulated liquid out there in a very short duration. These findings of the liquid dynamics could be helpful for exploring etiology of some laryngeal pathology, optimizing laryngeal disease treatment, understanding hemodynamics in the vocal folds, etc.
Perception of Canadian French rhotic vowels
Authors: Lamontagne Jeffrey , Mielke Jeff
Published: May 2013

Some speakers of Canadian French produce words such as pneu, un, and coeur with rhotic-sounding vowels similar to English /ɹ/ (Dumas 1972). Articulatory imaging [Mielke (2011)] shows that they are produced with bunched and retroflex tongue postures and low F3, much like English /ɹ/. Nevertheless, native speakers typically are completely unaware of the difference, even when it is pointed out to them. We report a preliminary perception study of rhotic vowels. 7735 words with mid front round vowels were coded as “rhotic,” “non-rhotic,” or “ambiguous” by two listeners: a French-English bilingual from eastern Ontario and an American English speaker. The bilingual coded 0.3% as rhotic (vs. 10.0% for the anglophone) and 7.3% as ambiguous (vs. 8.9%). Logistic regressions show that the anglophone relied on F3 to distinguish rhotic+ambiguous tokens from non-rhotic tokens, while the bilingual weighted several cues about equally, including F1 cues to diphthongization, which can co-occur with rhoticity. Results will be presented from an ongoing AX discrimination task experiment involving rhotic, non-rhotic, and ambiguous vowel tokens, with francophone, bilingual, and anglophone listeners from the Ottawa-Gatineau region, Paris, France, and Raleigh, North Carolina.
Intrinsic variations in jaw deviations in English vowels
Authors: Menezes Caroline , Erickson Donna
Published: May 2013

Research shows that jaw deviations follow lexical and phrasal stress patterns reflecting the rhythmic structure of English [Erickson (2002), (2010), Erickson et al. (in press), Menezes (2003), Menezes et al. (2003)]. Syllable strength thus can be determined by the amount of jaw displacement regardless of the target vowel. This study systematically analyzes jaw displacement based on the intrinsic variations in vowel height. EMA recordings were analyzed of one speaker producing a short phrase wherein 11 English vowels were spoken in a controlled phonetic environment. The phrase used was “Type X first” where, X was a closed monosyllabic word containing the target vowel surrounded by stop consonants. Stop consonants allow the jaw to start from the bite plane and return to the bite plane therefore all deviations of the jaw are attributed to the articulation of the vowel. The target word was produced in phrase initial, middle and final positions. Comparisons were made across vowel height, tongue root advancement and phrase position. Preliminary findings reveal that jaw displacement was significantly different at the level of p = 0.05 for vowels based on all three parameters: Vowel height, vowel tense/lax, and phrasal positioning.
An acoustic study of the Mary-merry-marry vowels in the Mid-Atlantic United States
Authors: Bauman Carina
Published: May 2013

This paper examines the acoustic properties of a subset of American English vowels before /r/--specifically, the mid and low front vowels in the MARY, MERRY, and MARRY classes. While the dialectal variation associated with the MARY, MERRY, and MARRY classes is well known in the sociolinguistics literature, the precise phonetic nature of these vowels has not been well studied. Many scholars [e.g., Labov et al. (2006)] transcribe the vowels as /eɪ/, /ɛ/, and /æ/, respectively, but these labels are largely impressionistic. The present study samples five speakers from the Mid-Atlantic region of the United States who maintain a three-way distinction between MARY, MERRY, and MARRY. The speakers' productions of MARY, MERRY, and MARRY vowels in both sentence and word list tasks were analyzed in Praat, and the resultant formant values were submitted to one-way ANOVAs, followed by pairwise comparisons (Tukey's HSD). The primary finding of this study is that the MARY vowel is acoustically closest to a tense (raised and fronted) variant of /æ/, similar to that which appears before nasals in many American English dialects. Contrary to previous descriptions, the MARY vowel shows little overlap with /eɪ/, suggesting that the conventional transcription should be revised.
Effects of variation on processing of word-medial consonants
Authors: Tucker Benjamin V. , Mackie Kaitlin , Kryuchkova Tatiana
Published: May 2013

The present study investigates processing of variation in word-medial stops and the role of this variation in phoneme recognition. Variation in word-medial stops has been shown to influence lexical access, but it is unclear whether this variation also affects recognition at the phoneme level [Tucker, J. Phonet., 39, (2011), 312–318]. A phoneme monitoring task is used to investigate the role of production variation in the identification of word-medial stop consonants. Following Warner and Tucker [J. Acoust. Soc. Am. 130, (2012), 1606–1617], the stimuli comprise English nonwords with target consonants [b], [p], [d], [t], [g], [k] in an intervocalic post-stress position produced with a range of production variation. This variation was grouped into three sets including groups at each extremes and a group in the middle of the range. The acoustic characteristics of the stops, which reflect this variation (e.g., consonant duration and intensity difference) were extracted and used to model the reaction times collected during the phoneme monitoring experiment. The reaction times were statistically modeled using a linear mixed-effects regression. Models of spoken word recognition and models of lexical storage are used to interpret the results and the contribution of the results to our understanding of these models is discussed.
Three-dimensional vocal tract modeling of fricatives /s/ and /sh/ for post-glossectomy speakers
Authors: Zhou Xinhui , Woo Jonghye , Stone Maureen , Espy-Wilson Carol
Published: May 2013

Production of fricatives involves a narrow supraglottal constriction along the vocal tract. Air flows through the constriction, and generates turbulent noise source(s) by impinging on some obstacles downstream. In post-glossectomy speakers, the production of /s/ and /sh/ is often problematic. It is mainly caused by the tongue surgery, which changes tongue properties such as volume, motility, and symmetry, preventing the tongue from creating proper constrictions. The purpose of this study was to gain some insights on how the vocal tracts of abnormal /s/ and /sh/ are shaped and what are their corresponding acoustic consequences. Based on cine magnetic resonance images, we built 3-D vocal tract models for /s/ and /sh/ from two post-glossectomy speakers (one with abnormal /s/ and the other with abnormal /sh/). Due to the missing part of the tongue, the reconstructed vocal tracts are asymmetric with either an air-flow bypass or a side branch formed near the constrictions. Two coupled physics submodels are included in the 3-D FEM acoustic simulation: incompressible potential flow for the mean air flow and aeroacoustics for the distributed noise sources. The resulting acoustic spectra and acoustic roles of air flow bypass or side branch will be discussed. [This study was supported by NIH R01CA133015.]
Neutralizing differences in jaw displacement for English vowels
Authors: Williams J. C. , Erickson Donna , Ozaki Yusuke , Suemitsu Atsuo , Minematsu Nobuaki , Fujimura Osamu
Published: May 2013

Maximum jaw displacement in the syllable varies primarily by vowel quality, syllable position in the phrase, lexical and phrasal stress, prosodic conditions, and the syllable consonantal periphery. EMA recordings were made of CVC syllables in 3-word phrases uttered by an American English speaker, where three target CVC words occurred in phrase initial, middle, and final positions, in order to ascertain the effect of vowel quality and syllable phrase position on jaw displacement, independent of other factors. Eleven English vowels, omitting diphthongs, formed the syllable nuclei, voiceless obstruents /p, t, k/ formed the syllable periphery, and the intonation pattern was kept constant for each phrase. Jaw displacement was measured by coil placement at the midline of the base of the lower incisors. The maximum vertical mandibular displacement on the vertical axis (z-axis for 3D EMA) was measured for each target CVC word. For each of the 11 vowels, an algorithm was developed to neutralize differences in the contribution of the mandibular vertical excursion in each of the three phrasal positions, i.e., 33 neutralization measures. These results indicate that this method may neutralize the mandibular contribution to differences in phonological vowel quality and phrasal position.
Exploring vowel mergers in northeast Ohio
Authors: Schmidt Anna M. , Weaver Kristin M.
Published: May 2013

The northeast corner of Ohio, as listed on dialect area maps, contains the boundaries of several dialect regions. This study compared perception and production for speakers from northeast Ohio and surrounding areas who merge and do not merge back vowels before /l/ in words such as “pool, pull, pole, dull.” Acoustic formant analysis indicated a lowered and fronted vowel, as expected, for those who merge some or all of these types of words but different patterns of merging were seen, especially when a final syllable was added as in “pulling.” Formant values were compared with values in “Luke” and “look.” Perceptually, preliminary results indicate that the merged vowel is often labeled as /u/ unlike findings for other US dialect regions such as Utah. Productions from over 100 speakers were situated on detailed dialect maps.
Development of a vocal tract design tool based on a growth curve of the vocal tract length
Authors: Ito Daisuke , Ogata Kohichi
Published: May 2013

One of the advantages of speech synthesis based on the vocal tract shapes is flexibility in speech sounds depending on the articulatory parameters. In order to take advantage of the flexibility, preparing various vocal tract shapes is important. To achieve this, this paper describes the development of a vocal tract design tool based on a growth curve of the vocal tract length reported by literature. In this tool, the growth curve is used to calculate the size of the vocal tract. A user can obtain a vocal tract shape depending on the age and sex using a slide button on the interface window. The parameters that describe vocal tract shape and vocal folds are used to produce vowel sounds and their formant frequencies are obtained. According to literature, there is a relationship between the fundamental frequency and formant frequencies through the age. We compared the formant frequencies calculated from the tool with those estimated from the literature. The comparison showed that the calculated formant frequencies were in relatively good agreement with the estimated ones. In addition, the distribution of the first and second formant frequencies showed a typical pentagonal distribution.