bluuebunny/crossref_metadata_2025 huggingface dataset:
Phonetic imitation by individuals with Autism Spectrum Disorders: Investigating the role of procedural and declarative memory
Authors: Mielke Jeff , Nielsen Kuniko , Magloughlin Lyra
Published: May 2013

This study investigates the role of procedural and declarative memory in phonetic imitation, by examining the word- and phoneme-specificity of imitation produced by individuals with autism spectrum disorders (ASD). Previous research has shown that individuals with ASD process language differently from the Neurotypical population [e.g., Ullman (2004), Walenski et al. (2006)], with Autistic individuals relying more on declarative memory. Previous work with the general population has shown a robust effect of phonetic convergence [e.g., Pardo (2006)], as well as generalization and weak word-specificity effects [Nielsen (2011)]. To test whether individuals with ASD exhibit increased specificity, we used Nielsen's (2011) experimental paradigm, which has been shown to elicit generalized phonetic imitation in the general population. A linear mixed effects regression analysis revealed that increased VOT on the modeled phoneme /p/ was imitated by both ASD and control groups [p < 0.05]. However, different patterns emerged in phoneme-level specificity: the control group exhibited sub-phonemic generalization (increasing VOT on /p/ and /k/), while the ASD group exhibited a phoneme-specific pattern (increasing VOT only on /p/) [p < 0.05]. Furthermore, a stronger trend toward word-specificity was observed within the ASD group. Taken together, these results confirm the earlier finding that ASD individuals exhibit greater reliance on declarative memory.
The segregation of target speech from competing speech when listening in a second language
Authors: Schneider Bruce A.
Published: May 2013

Introducing a perceived spatial separation (via the precedence effect) between target speech and competing speech reduces the signal-to-noise ratio (SNR) required for the recognition of key target words by 3–7 dB in syntactically correct but semantically anomalous target sentences such a “A rose could paint a fish” (target words: rose, paint, fish). A recent study of monolingual Mandarin participants listening to anomalous sentences in Mandarin Chinese suggests that perceived spatial separation releases listeners from informational masking (IM) by facilitating access to the lexicon at the morphemic level, presumably by enhancing the segregation of the target speech from the competing speech background. This raises the interesting question as to whether perceived spatial separation facilitates lexical access in the same way for people listening in the second language (L2) as it does when listening in their first language (L1) since access to the L2 lexicon is likely to be less robust than access to the L1 lexicon. A second interesting question is the extent to which operating in a L2 environment affects release from IM when the competing speech is in L1. These issues will be addressed in L2 English listeners whose L1 is either Chinese or Korean.
Exploring the factors predictive of informational masking in a speech recognition task
Authors: Gallun Frederick J. , Diedesch Anna C.
Published: May 2013

The effects of informational masking (IM) can be recast as a question of which cues to sound source identity (auditory object formation) are most useful for overcoming IM. We hypothesize that individual differences are related to specific interactions of stimulus and listener-specific variables that determine the effectiveness of the auditory object formation process. Results from our laboratory generally support the well-established relationship between performance and stimulus variables such as spectrotemporal cues (in this case, voice differences) and spatial cues (talker locations). In addition, the listener-specific variables of age and hearing loss were found to interact with the stimulus variables and to be correlated with potential mediating variables such as interaural time sensitivity and minimum levels at which speech identification was possible. Future work will involve developing predictive models that focus on identifying the mediating variables responsible for increased susceptibility to IM and efficient tests to reveal these relationships in individual listeners. The clinical relevance of the ability to identify factors predictive of IM susceptibility will be discussed, including the potential for improved fitting of hearing aids and cochlear implants.
Speaker identification made easy with pruned reassigned spectrograms
Authors: Fulop Sean A. , Kim Youngwook
Published: May 2013

One common scenario for speaker identification presents the task of identifying samples of speech from members of a previously enrolled group. One recent (and typical) set of results used 36 s of speech from each speaker to train Gaussian models by expectation-maximization during enrollment, and 20 s of speech for the test samples. Three major problems with this procedure are (1) sensitivity to noise; (2) impractical amounts of speech are required; (3) computationally expensive training is required. In our study, the reassigned spectrogram is pruned using phase-derivative indicator functions to provide a sparse time-frequency matrix of very small (40 ms) samples of speech. The pruning eliminates Gaussian noise up to ~1 dB SNR. Principle components analysis provided a set of 30 features from each spectrogram. Using an enrolled group of 24 speakers recorded under low-fidelity conditions, 83% identification accuracy (comparable to state of the art results with 6 dB SNR) was achieved from real-time classification methods (e.g., support vector machines) without need for extensive training. Moreover, these results extend to 1 dB SNR where standard techniques break down. The three main problems of speaker identification can thus be better addressed by our methodology.
Single snapshot spatial array processing using time-frequency distributions
Authors: Sabra Karim G.
Published: May 2013

Several signal processing applications, such as spatial beamforming, rely on data collected by an array of sensor to estimate to enhance a weak signal in the presence of noise (e.g., ambient noise or clutter). The commonly applied eigenstructure subspace methods to this signal denoising problem assume stationary signals and require multiple snapshots to correctly estimate the covariance matrix of the array data. However, these multiple snapshots and stationarity requirements can be hard to meet in practical scenarios involving among others a rapidly moving source (which causes differential Doppler effect among sensors) or a single snapshot of the aspect-dependent scattering of an unknown target as measured by a monostatic sonar system (such as side-scan sonar). To handle these scenarios, we propose to form a generalized space-time-frequency covariance matrix from the single-snapshot data by computing Cohen’s class time-frequency distributions between all sensor data pairs. The eigenstructure of this space-time-frequency covariance matrix allows to enhance the localization of the signal of interest while spreading the noise power in the time-frequency domain. Hence, this approach is especially suited to handle nonstationary echoes of underwater target resonances that are highly localized in the time-frequency domain as demonstrated using numerical and at-sea data.
Time frequency analysis techniques for long range sediment tomography
Authors: Potty Gopu R. , Miller James H.
Published: May 2013

Long range sediment tomography inversion technique requires accurate estimation of the arrival times of acoustic normal modes. The inversion technique is based on minimizing the difference between the forward model predictions and the data using a global optimization scheme. Predictions are computed using a trial parameter set which is iteratively modified until the algorithm converges. The modal arrival times are calculated from the time-frequency analysis of broadband acoustic data collected on a single hydrophone. During the initial stages of the development of the inversion scheme, Fourier-based spectrograms and wavelet-based scalograms were used. Taking advantage of some of the recent developments, dispersion based short time Fourier transform (DSTFT) and warping transform techniques were used for the time-frequency analysis, in recent times. This paper will summarize and compare the performance of these time frequency techniques in the context of long range sediment tomography. Data from some of the recent field tests (Shelfbreak Primer and Shallow Water-06 experiments) will be analyzed for this study. Finally, time-frequency analysis performance of another new technique, Modified S transform, will be examined using the field data. [Work supported by Office of Naval Research].
Time-frequency analysis of wood anomalies in acoustics
Authors: Liu Jingfei , Declercq Nico F.
Published: May 2013

When performing a Fourier transform on the reflection from a periodically corrugated surface for a normally incident beam the reflection spectrum is obtained. Steep dips have been observed from such reflection spectrum and are commonly called Wood anomaly. Because the frequencies at which Wood anomalies appears coincide with the frequencies where stimulation of Scholte-Stoneley waves is expected, Wood anomalies are traditionally explained as being caused by Scholte-Stoneley waves and as drain of energy. In this work, time-frequency domain analysis is made on the reflection from corrugated surfaces. The analysis suggests that Wood anomalies only occur when the entire reflection is processed by a Fourier transform, whereas for short time Fourier analysis this phenomenon does not seem to occur. The analysis also shows that energy is delayed in the time domain at the generation frequency of Scholte-Stoneley waves, and is therefore not necessarily drained. From the time-frequency point of view the source of Wood anomalies is re-examined and the actual relationship between the surface wave generation and Wood anomalies is also investigated.
Measurements of Brillouin gain spectra in erbium-doped optical fibers for long-distance distributed strain and temperature sensing
Authors: Ding Mingjie , Mizuno Yosuke , Hayashi Neisei , Nakamura Kentaro
Published: May 2013

Brillouin scattering, one of the most important acousto-optical phenomena, occurs when lightwave interacts with periodical refractive-index change caused by the acoustic wave. The frequency downshift from the incident light to the backscattered Stokes light is called the Brillouin frequency shift (BFS), which depends on the strain/temperature applied to the optical fiber. Fiber-optic distributed Brillouin sensors have already been widely utilized to monitor strain/temperature conditions of structures including buildings, bridges and cables. The measurement range of the sensing system is partially limited by the optical propagation loss inside the sensing fiber. One solution is to employ special fibers capable of amplifying Brillouin signal. In this work, we employ erbium-doped fibers (EDFs) as sensing fibers, which are commonly used as 1550 nm optical amplifiers. As the first step, we investigated the strain/temperature dependence of Brillouin gain spectra (BGS) in EDFs with three different erbium concentrations. For all the samples, with increasing strain/temperature, the BGS shifted toward higher frequency, which was the same as that of silica fibers. Moreover, as the erbium concentration increased, the strain coefficient of BFS was increased, while its temperature coefficient was reduced. These results will definitely contribute to the future research of EDF-based distributed strain/temperature sensing systems.
The shallow sea experiment with usage of linear hydrophone array
Authors: Szymczak Wojciech , Kozaczka Eugeniusz , Grelowska Grazyna , Gloza Ignacy , Kozaczka Sławomir
Published: May 2013

Purpose of this article is to present designed and made linear hydrophone array and the results obtained during in situ trails on Gulf of Gdańsk. The measuring system allowed to localize hydrophones in the selected points and perform measurements in both the horizontal antenna positioning and vertical. Made in this way recordings allow creating accurate 3D imaging of sound intensity/propagation. During research three floating objects were measured: small ship (18 m long), yacht (12 m long) and 5 m pontoon with engine and paddles used to drive. In the article, accurately will be described the entire measurement system and complementary devices (navigation system, sound speed profiler, online underwater monitoring to control linear antenna position) and procedures used during in situ measurement circuit check and calibration using Lubell Underwater Speaker with amplifier and connected generator with set of reference signals. Characteristic arrangement of sensors allows use of hyperbolic navigation algorithms which results will be presented with an emphasis on measurements when the unit performed circulation around the measurement system. Furthermore, some spectrograms, cross correlations and frequency classification dependence of the speed using a prepared script in Matlab programing environment will be discussed and presented.
Environmental acoustic parameters of the Sea of Japan shelf (Peter the Great Gulf)
Authors: Samchenko Alexandr N. , Yaroshchuk Igor O. , Kosheleva Alexandra V.
Published: May 2013

The paper describes general geoacoustic model of the Peter the Great Gulf (the largest gulf of the Sea of Japan) and detailed model of its part of 400 square km in size. The general geoacoustic model is formed on the basis of geological, seismic, and bathymetric data. It includes distribution of P-, S-wave, density, and attenuation of friable sediments at the bottom surface and averaged characteristics for different types of rocks in the gulf. Bathymetric data processing was carried out by means of two-dimensional singular spectrum analysis, based on the ratio between the size of relief structures and the energy expended under the development of tectonic processes. Detailed geoacoustic model is based on processing of hydroacoustic and seismic authors’ studies (3.5 kHz sonar, 50–100 kHz sonar and air-gun). Three sedimentary layers and the location of upper edge of the granite stratum are marked in the observable shelf area. The model demonstrates significant changes in P-, S-wave in the sediments of the lateral (1500–1750 m/s—P-wave and 120–600 m/s—S-wave) and vertical (1500–5400 m/s—P-wave and 120–3300 m/s—S-wave). Some of the most important oceanographic mechanisms determining both large- and small-scale spatio-temporal variations of sound speed field in the same area are presented. These data were obtained by the authors within last several years. Qualitative analysis of the propagation of low-frequency signals is presented as an example of application of the model.
Three-dimensional sound spatialization at Auditorio400 in Madrid designed by Jean Nouvel
Authors: del Cerro Emiliano , Ortiz Silvia Mª
Published: May 2013

The auditorium 400 was designed by the team of Jean Nouvel, the French architect, Pritzker Prize winner in 2008. It belongs to the organization of the National Museum and Reina Sofia Art Centre in Madrid, and is incorporated in a special room within the cultural life of Madrid (Spain). The center collaborates with the Spanish Ministry of Culture, and organizes a series of concerts of contemporary music and electronic and computer music. To achieve the sound projection equipment, the direction of the audience chose the system Acousmonium, designed by the GRM inside the ORTF in Paris. This paper will explain the involvement of the group LIEM (laboratory for Computer and Electronic Music), from Reina Sofia Museum with space in music: The musical relationships and implications of this choice, as well as the technical, architectural, and signal processing techniques used for the design of algorithms for spacialization of sound. After giving a very general overview of specific algorithms for spacialization, we explain some musicals examples designed specifically for this space, and the impact of its implementation and diffusion in the auditorium400 that have very special technical and artistic features.
Effect of acoustic and visual stimuli on preference for different seating positions in a concert hall and an opera theater
Authors: Sato Shin-ichi , Saavedra Adrián , Bidondo Alejandro , Wang Shuo , Zhao Yuezhe , Wu Shuoxian , Prodi Nicola , Pompoli Roberto
Published: May 2013

The sound fields and the views of several positions in a concert hall and an opera theater were simulated and the subjective preference for different seating positions was investigated. First, the seat preference with and without visual stimuli under the conditions of (1) the original sound level (the sound pressure level at each position was maintained as the impulse response measurements in the auditoria) and (2) the equalized sound level were compared since the subjective scale of seat preference showed the highest correlation with sound level in the previous study investigating the opera theater [Sato et al., Acustica united with Acta Acustica 98, 749–759 (2012)]. Some positions were judged acoustically preferred but visually less preferred or vice versa. Thus, another preference test was conducted by using the combinations of the acoustic and the visual stimuli of different positions to further investigate the audio-visual interaction.
Risk and innovation—Following on from the 2012 Knudsen Lecture, recent experience with calculated risk for the purpose of creating remarkable spaces is reviewed
Authors: Pfeiffer Scott D.
Published: May 2013

Owner expectations, architectural vision, and creation of the intended aural environment often come together at a critical point in the design process. Frequently the answer that satisfies all of the requirements stretches the comfort level of all parties. When balanced properly, this element of risk frees the entire project team and reaches unexpected, but welcome, outcomes. The author will illustrate these critical decision points in several project examples, outlining the calculation in the calculated risk, and the opportunity to deepen the confidence in the consulting process through further research.
Letters from the edge: Less conventional acoustical solutions
Authors: Evans Jack B.
Published: May 2013

The essence of acoustical analysis and problem solving still is source–path–receiver; yet, as standards, criteria and products evolve, solution precedents should be revalidated or invalidated, so that new, innovative approaches may be considered. While weighing the best interests of the client, should one rigidly follow procedures developed long ago for average or anticipated conditions, or might the conventional wisdom not always be correct? This paper presents a series of short case-studies where noise or vibration were treated at the source and/or along the path, but with some “twist” or variation, either from typical solution applications or owner/client response. Relevant standards, ordinances, or criteria are referenced. Where available, on-site acoustical measurements, observations, photos, or receiver experiences illustrate concepts. For the case studies presented: indicate (i) importance of the problem, (ii) method of the development used for problem solving, (iii) original contribution of the work, and (iv) conclusions. Case studies may include any of the following: standby power generators for data center, university cafeteria, and dining hall, coffee grinding and packaging shop within a grocery market, exercise/therapy floor impact above offices, air-cooled refrigeration chillers near residences, high-rise elevator equipment room adjacent to residential units, and/or high-rise domestic water booster/circulation pump room adjacent to residential unit.
Design and implementation of a tuned low-frequency absorber in a residential music listening/practice room
Authors: Farbo Aaron M. , Storch Christopher A.
Published: May 2013

The historic Bradley Mansion in Boston’s Back Bay neighborhood was recently completely renovated and subdivided into multiple luxury-level condominium units built to suit to the new homeowners requirements. The historic preservation requirements imposed on the project presented challenges for designing and implementing sufficient acoustic absorption and sound isolation for the design of a new music listening and piano practice room in the lowest level residence. A custom-designed low-frequency absorber was developed to fit within an existing architectural niche at one end of the elliptical music room, and additional absorptive treatment was added to the walls to blend in with the existing finishes. Sound isolation to the neighboring condominium above the music room was improved via floor/ceiling modifications—a task made more challenging by the need to retain the terracotta structure and other historic details. Construction details and measurement results will be discussed in this case study presentation.
Coping with curves in room design
Authors: Foulkes Timothy
Published: May 2013

Concave curves are pleasing to the eye, but they cause a number of different acoustic anomalies. Depending on the radius of curvature, finish material, included angle, and position relative to source and receiver, one may hear a strong return echo, a noticeable coloration of the frequency balance, a dramatic shift in the acoustic image, or extended reverberation at low frequencies. The effects of standard curved forms such as the Capital rotunda are well known. These anomalies are of little consequence in a transient space such as a lobby, but are problematic in rooms for speech and music presentation. Covering the entirety of the concave surface with sound absorbing material is not always the best solution. In most cases, the client will want to know the minimum acoustic treatment to avoid complaints. The author will present a series of case studies showing room designs with concave curves and the acoustic solutions.
Reverberlocation in chickadees?
Authors: Mercado Eduardo , Wisniewski Matthew W. , McIntosh Brittany E. , Guillette Lauren M. , Sturdy Christopher B.
Published: May 2013

Chickadee songs provide conspecifics with information about the locations of singers. Song amplitude, frequency, and reverberation all vary with distance, and it is thought that chickadees use such cues to estimate distance. The current study examined transmission of chickadee songs in an open field to assess whether other cues such as relative changes in inter-note timing or relative differences in spectral energy might also provide useful information about a singer’s location. Surprisingly, the difference between direct signal energy and reverberant spectral energy provided clear indications of how far a song had traveled. Preliminary analyses suggest that this cue may be robust to variations in source level, note duration, note frequency, and transmission loss. If chickadees use this cue to judge auditory distance, then this may explain why they maintain specific spectral ratios between the notes within their songs. Specifically, the spectral spacing of notes within songs appears to be directly related to chickadee auditory filter bandwidth. We describe ranging of a singing chickadee based on the spectral profile of its songs as reverberlocation (construed as an instance of passive echolocation) because it involves comparisons between a direct signal and echoes of a signal.
Localization of flying insects by echolocation
Authors: Matsuo Ikuo , Takanashi Takuma
Published: May 2013

Using the echolocation, bats can capture insects in real 3D space. Bats can accurately localize these objects from echoes by emitting the frequency modulation sound. The object’s range could be estimated from delay times between the emitted sound and echoes from objects. In the case of flying insects, the echoes were influenced by Doppler shift, that is, the wing beats and flight speed. In the case of the linear frequency modulated (LFM) sound, this range accuracy was dependent on not only the frequency width of emitted sound but also the Doppler shift. It has been shown that the previous proposed model could accurately estimate each range of static objects by using the frequency modulation sound. However, it was unknown whether this model could estimate locations and movements of the flying insect. In this study, the echoes were measured from the flying insect by emitting intermittently the LFM sounds. At the same time, the movements of the insects were measured by the camera. The time-frequency pattern were computed by using the convolution of the chirplet filters. It was examined that the the insect’s positions were estimated by extracting the onset from the time-frequency pattern. [Research supported by JST, CREST.]
Preliminary results from collaborative referring to impulsive sonar sounds
Authors: Gaumond Charles F. , Brock Derek , Wasylyshyn Christina
Published: May 2013

A recent experiment is described wherein pairs of listeners (a “director” and a “matcher”) collaboratively refer to eight-element sets of impulsive sonar sounds, which are the same, but ordered differently for each listener. The sounds in a given set are privately displayed on each listener's computer as a line of blank cards that play a corresponding sound when clicked and can be rearranged from left to right. The listeners’ task is to move the matcher's sounds into the same order as the director's. Through conversation, the listeners work out how to verbally characterize the sounds and develop a shared vocabulary. This vocabulary is presented for selected participants and is shown to generally consist of names, actions, and properties of familiar, everyday auditory events. In general, these references function as classes and descriptors. Classes correspond to causal categories that are aurally analogous to (i.e., homophonic with) the acoustic origins of the impulsive sonar sounds. Similarly, descriptors, distinguish between the properties of signal processing features that are appropriate to impulsive sounds within a given category. [Research funded by the Office of Naval Research.]
An auditory perception of changes in the intensity of pulses, presented in complicated sound complex
Authors: Rimskaya-Korsakova Liudmila K.
Published: May 2013

The auditory system of humans and animals is able to detect and discriminate high frequency pulses in a complicated sound complex. The purpose of the work was to find new examples of a facilitation the discrimination of intensity (or level, defined by a peak amplitude) of a test pulses, presented under composite masking conditions, and to find the possible mechanisms underlying the facilitation. The discrimination tended to deteriorate if the test pulse was presented through 50 ms after a pulse’s masker. However, if the test pulse was mixed with stationary noise, the beginning of which coincided with the end of the pulse’s masker, discrimination became better. The noise levels, at which facilitation occurred, depended on amplitudes of both the test pulses and the pulse’s maskers. When the duration of the noise was less than 50 ms, an auditory adaptation could not influence on the discrimination. The reason of the facilitation could be in the temporal redistribution of the auditory nerve fibers activities, which occurred at coding of the complicated sound complex “pulse’s masker - test pulse - stationary noise.”
Influence on sound spread considering the flow velocity in a horizontal layer media
Authors: Song Yang , Zhao Zhenqi
Published: May 2013

The marine currents could often influence sound propagation underwater. The traveling time of sound ray is distinctly effected by the velocity of current in some conditions. So it will be made certain errors in seeking eigen rays and inversing sound speed profile if the velocity of the current is ignored. In order to improve the computation accuracy of sound ray model, a sound ray model of horizontal layer is induced in which the media flow is considered. Eigen rays are searched and their traveling time is calculated by the ray model. It is also discussed that the velocity of flow media influences ray trace and traveling time. An average sound speed profile measured under a shallow water is cited to calculate the eigen rays. The differences of sound ray are given under two kinds of condition which the velocity of current is considered and not considered. The computation results show that the sound ray trace is changed indistinctively under small Mach number condition, but the traveling time of eigen rays is fluctuated obviously. The fluctuation of ray traveling time is bigger according to the larger Mach number and the longer spread distance. The results of study will provide some help in the inversion of ocean acoustic tomography.
Coupling elastic-poroelastic material in structure-borne sound modeling
Authors: Rurkowska Katherina , Langer Sabine
Published: May 2013

Porous materials are widely used in noise reduction applications. To minimize the external noise produced by aircraft propeller drives, porous materials are implemented. As a part of the project Sonderforschungsbereich 880 “Fundamentals of High Lift for Future Civil Aircraft,” porous surfaces are used in the High-lift configuration to mitigate the flow noise and to influence the structure-borne sound. In order to model the performance of the applied poroelastic material, an approach coupling a poroelastic material with an elastic structure using Finite Element Method is presented. The Biot's theory is used to model the poroelastic material. The aim of this work is to simulate the effect of the entry and transmission of the structure-borne sound into the poroelastic medium. An example of the implemented model shows the plausibility of presented approach.
Numerical investigation of the functionally graded materials by the interaction of the plate guided waves with discontinuities and cracks
Authors: Benmeddour Farouk , Moulin Emmanuel , Assaad Jamal
Published: May 2013

This work intends to give a better comprehension of the guided wave interactions with damage in a functionally graded material (FGM). The propagation and interactions of plate guided waves with discontinuities in a FGM composed of ceramic and metal mixture are investigated. For this purpose, a two dimensional finite element (FE) method is used to analyze the near field surrounding the damage. Then, expansion of the solution into sums of guided modes enables the determination of the reflection and transmission coefficients of each existent mode. The determination of the modal features is ensured by the way of the so called semi-analytical finite element (SAFE) method applied to the one dimensional inlet and outlet cross-sections. The latter has the benefit to study an arbitrary shape-like damage in an infinite structure having the same shape by translation in the propagation direction in a fast and efficient way. Results are obtained by solving the global system of the 2D hybrid FE-SAFE method. Different symmetrical and asymmetrical notches are studied and so for cracks. Results are achieved and discussed for a FGM and compared to those obtained for an isotropic material.
Generalized Debye series expansion to improve the non-destructive testing and health monitoring of cylindrical structures by guided waves
Authors: Yaacoubi Slah , Deschamps Marc , Ducasse Eric , Laguerre Laurent , Yaacoubi Weina Ke , McKeon Peter , Ramadan Salah , Declercq Nico F.
Published: May 2013

Many structures in civil engineering notably bridges and nuclear power plants must be regularly, strictly, and carefully tested to avoid any human or environmental catastrophe. Among the NDT techniques, which can be applied, ultrasonic guided waves are a good candidate to monitor bars and cables. However, its multimodal and dispersive behaviors can limit its performances. Theoretical modeling is sometimes needed to understand the behavior of the traveling waves to improve the testing/monitoring and made a right in-situ decision. The aim of this paper is to derive the space-time velocity field in a cylindrical waveguide perfectly embedded in an infinite solid matrix and generated by an inside bounded beam. This beam is generated by an off-axis source. Vector Hankel transform and Fourier series are combined to decompose the inside field into infinity of elementary cylindrical waves propagating in radial direction and planar waves propagating in axial direction. Global resolution method and Generalized Debye series expansion are used both to calculate the 3D global cylindrical reflection/transmission coefficients. The method is demonstrated through a steel bar embedded in cement matrix. Simulated frequency–wavenumber diagrams show that the embedding material acts like filter for different frequency ranges. Other results will be presented.
Energy flux streamlines versus acoustic rays for modeling interaction with rigid boundaries: near field of sound from a circular loudspeaker
Authors: Dean Cleon E. , Braselton James P.
Published: May 2013

Sound emitted by a circular loudspeaker can be treated as equivalent to a plane wave diffracted by a circular aperture in a rigid, sound absorbing screen. Axial symmetry leads one to expect constructive interference along the symmetry axis in the near field (the Poisson-Arago spot). An energy flux streamline model was developed to help visualize this and other features of the near sound field. The model is used to draw out similarities and differences between energy flux streamlines and acoustic rays, particularly in the transition to the far field.
Timbre as a structuring force in music
Authors: McAdams Stephen
Published: May 2013

Most of the music we enjoy uses the musical qualities of different instruments to create specific perceptual and emotional effects that composers sculpt over time. Timbre is the auditory attribute that distinguishes different instruments. Research on timbre perception has demonstrated that it is multifaceted and contributes in many ways to the perceptual organization of musical structures. The art of structuring music with timbre is orchestration. A survey of orchestration treatises reveals the dearth of underlying theory, in sharp contrast to other traditional areas such as harmony and counterpoint, which have long theoretical traditions. We seek to develop a theoretical ground for orchestration practice starting with the structuring role that timbre can play in music. Many aspects of musical structuring are achieved by auditory scene analysis, the perceptual processes that result in unified events, integrated streams of events, groups of events segmented into phrases and sections, and larger-scale units extended over time that we call orchestral gestures. The roles that timbre plays in the manifestation of these principles in orchestration practice will be considered as potential elements of a theory of orchestration. How such principles might be incorporated into computer-aided orchestration systems and computer-aided orchestral rendering systems will also be examined.
Predicting blend between orchestral timbres using generalized spectral-envelope descriptions
Authors: Lembke Sven-Amin , Narmour Eugene , McAdams Stephen
Published: May 2013

Composers rely on implicit knowledge of instrument timbres to achieve certain effects in orchestration. In the context of perceptual blending between orchestral timbres, holistic acoustical descriptions of instrument-specific traits can assist in the selection of suitable instrument combinations. The chosen mode of description utilizes spectral-envelope estimates that are acquired as pitch-invariant descriptions of instruments at different dynamic markings. Prominent local spectral-envelope traits, such as spectral maxima or formants, have been shown to influence timbre blending, involving frequency relationships between local spectral features, their prominence as formants, and constraints imposed by the human auditory system. We present computational approaches to predict timbre blend that are based on these factors and explain around 85% of the variance in behavioral timbre-blend data. Multiple linear regression is employed in modeling a range of behavioral data acquired in different experimental investigations. These include parametric investigations of formant frequency and magnitude relationships as well as arbitrary combinations of recorded instrument audio samples in dyads or triads. The cataloguing of generalized acoustical descriptions of instruments and associated timbre-blend predictions for various instrument combinations could serve as a valuable aid to orchestration practice in the future.
Wind farm—Long term noise and vibration measurements
Authors: Meunier Martin
Published: May 2013

Most of the energy produced in Quebec comes from renewable sources. The concept of wind energy emerged in the late 1990’s and has since become a complementary source of energy alongside hydroelectricity. Wind farms are generally seen as a good sustainable way to produce energy. However, they are not implemented without some impact on the environment. SNC-Lavalin Environment has performed many surveys in recent years for wind farm projects, including noise measurements both before and after their commissioning. This presentation will give an overview of one such project where long term noise and vibration measurements where conducted. Vibration measurements, as well as outdoor, indoor, and low frequencies noise measurements were completed both with and without the wind turbines in operation. Data will be presented showing different problems encountered in the analysis phase. For example, multiple intermittent and non-steady noise sources were present during measurement (wind turbines, car pass-bys, wind in the trees, human activities). Methods used to overcome these obstacles will be discussed (use of statistical parameters, linear regression), and the effect of the wind turbine operation on the noise level (including low frequencies) and vibration level will be presented.
Building integrated wind turbines—A pilot study
Authors: Dymock Ben , Dance Stephen
Published: May 2013

The current planning guidance in London requires that all new or refurnished large buildings should include 20% renewables. As part of a study on urban wind a pilot investigation based on the building integrated wind turbines on the skyscraper Strata Tower in London will be monitored for acoustics, vibration, anemometry and electrical generation. Strata Tower is a 150 m building in an urban location with three 19 kWe turbines in a specially designed venturi housing. The effect of the wind turbines on residents, the local community, and the building structure will be assessed and reported.
Assessment of annoyance due to wind turbine noise
Authors: Pawlaczyk-Luszczynska Malgorzata , Dudarewicz Adam , Zaborowski Kamil , Zamojska Malgorzata , Waszkowska Malgorzata
Published: May 2013

The overall aim of this study was to evaluate the perception and annoyance of noise from wind turbines in populated areas of Poland. The study group comprised 378 subjects. All subjects were interviewed using a questionnaire developed to enable evaluation of their living conditions, including prevalence of annoyance due to noise from wind turbines, and the self-assessment of physical health and well-being. In addition, current mental health status of respondents was assessed using Goldberg General Health Questionnaire GHQ-12. For areas where respondents lived, A-weighted sound pressure levels (SPLs) were calculated as the sum of the contributions from the wind power plants in the specific area. It has been shown that the wind turbine noise at the calculated A-weighted SPL of 30−50 dB was perceived as annoying outdoors by about one third of respondents, while indoors by one fifth of them. The proportions of the respondents annoyed by the wind turbine noise increased with increasing A-weighted sound pressure level. Subjects’ attitude to wind turbines in general and sensitivity to landscape littering was found to have significant impact on the perceived annoyance. Further studies are needed, including a larger number of respondents, before firm conclusions can be drawn.
Designing canopies to improve downwind shielding at various barrier configurations at short and long distance
Authors: Van Renterghem Timothy , Botteldooren Dick
Published: May 2013

The positive effect of a row of trees to improve downwind shielding in the acoustic shadow zone behind a noise wall has been shown before by means of a wind tunnel experiment, a field study and by numerical simulations. This research focused at a rather short distance in downwind direction, where important recovery of the shielding lost by screen-induced wind refraction was observed. However, opposite effects are possible at longer distance. This can be explained by shifts in the zones with strong (positive) gradients in the horizontal component of the wind speed. Leaving a gap between the barrier top and canopy bottom helps reducing these negative effects at longer distance, and results in a generally optimized performance downwind. Trees behind noise walls at either side of the source lead to a full canceling of wind effects at short distance, but to strong negative effects at longer distances downwind. Trees as windbreaks seem to be especially useful near single, vertically erected noise walls. Near steep berms, no net effect of trees is predicted. The design rules presented in this paper are derived based on numerical calculations with a previously validated CFD-FDTD-PE model.
In-situ measurements of sound reflection and sound insulation of noise barriers: Validation by means of signal-to-noise ratio calculations
Authors: Garai Massimo , Guidorzi Paolo
Published: May 2013

After some years from its first release, the CEN/TS 1793-5 European standard for in-situ measurement of sound reflection and airborne sound insulation characteristics of noise barriers has been significantly enhanced and validated in the frame of the EU funded QUIESST project. The procedure, based on impulse response measurements near the noise barrier and in the free field, is robust and easily applicable but much attention must be paid when: (i) applying the signal subtraction technique to get the reflected signal component and (ii) extracting the transmitted component, especially measuring highly insulating noise barriers. In both cases, it is essential to avoid a poor signal-to-noise ratio of the critical part of the impulse response. In the frame of the QUIESST project specific quality criteria, applicable on site, have been introduced in order to check and validate the result. These criteria are rigorously described here for the first time and illustrative examples are presented.
Determination of noise emission data of construction sites
Authors: Tsukernikov Ilya E. , Shubin Igor L. , Ivanov Nikolay I. , Nevenchannaya Tatiana O. , Nekrasov Igor A.
Published: May 2013

The reasons for development and substantive provisions of Russian standard GOST R 53695-2009 “Noise. Method for determination of noise emission data of construction sites” are presented. The concept of the noise emission characteristics of a construction site and the method of their determination are entered. Various kinds of civil work, construction site location, environment acoustic conditions, and feature of a landscape are taken into account. Instead of noise of separate sources operating inside a construction site noise of the construction site as a whole sound source is considered. The mean time averaged and maximum values of A-weighted sound pressure levels along the sides of a construction site are taken as its noise emission data. Sound reflection from the barriers located near to a construction site is considered by means of environmental correction for which determination the special method was developed. Procedures of determination of measurement uncertainty, the noise characteristics declared values which are brought in construction site specifications and accuracy degree of the method to be applied are considered.
Aerodynamic noise reduction of a gangway in a high-speed train
Authors: Noh Hee-Min , Koh Hyo-In
Published: May 2013

Excessive interior noise of high-speed trains causes annoyance, fatigue, and stress to passengers. Moreover, the noise occurred in gangway is greater than other noise in the room. Therefore, a research for gangway noise reduction was carried out. At first, cavity noise which causes major noise between car-sections was simulated with Fluent 6.0 (computer fluid dynamics program). From the simulation result, the flow feedback loop phenomena in the cavity were observed. Then, noise measurements at internal and external positions in between-cars sections were conducted during the driving of a high-speed train. From the measurement results, noise characteristics of gangway and between-cars section were identified. Finally, noise mitigation methods were suggested in this paper.
A consideration on sound masking system for achieving speech privacy using parametric acoustic array speaker
Authors: Tamesue Takahiro , Saeki Tetsuro
Published: May 2013

Speech privacy in open spaces is becoming increasingly important in various situations. Although measures such as the use of sound partitions are already used in many cases, measures that mask speech by emitting sounds have also been considered. A method of masking meaningful speech with meaningless noise would be valuable. Because of this, previous studies have investigated the ability of meaningless steady noise to mask speech and consequently achieve speech privacy. However, the research to date has focused on evaluating speech privacy when the masking noise is emitted from the normal loud speaker system all over the room. The masking noise emitted to the area where high level of speech privacy is not required, may cause an increased psychological impression of annoyance, leading to a decline in performance. In this study, we used a highly directional sound from modulated ultrasound as a masking noise for achieving speech privacy in the narrow area. Psychological experiments were conducted in which the masking sound was transmitted to participants from frontal or above directions with a parametric acoustic array speaker. Using the experimental data, the relationships between the degree of speech privacy and frequency characteristics and directivity of parametric acoustic array speaker were investigated. The results suggested that it is possible to maintain speech privacy in the narrow area by presenting highly directional masking sound.
Effects of age on feasible sound level of possible warning sounds for quiet vehicles
Authors: Yamauchi Katsuya , Shiizu Takayuki , Tamura Fumio , Takeda Yuichiro
Published: May 2013

It has been noted that reduced noise can also lead to potentially dangerous situations for pedestrians because electric and hybrid vehicles are quieter than conventional internal combustion engine vehicles. Hence, the use of warning sounds which are radiated by the vehicle to alert pedestrians is being considered by various governments. To design the sound itself or to develop the regulation concerning the sound, it is much important to know the feasible sound level of the warning sounds compared to the background sounds. Pilot studies on this topic were performed by Yamauchi et al. in 2011 with young subjects. This present study was aimed to reveal the effect of age on feasible sound level of warning sounds. In the experiment, level of five possible warning sounds was adjusted in three different urban environmental sounds in a laboratory. Thirty subjects aged from 19 to 74 years old participated in the experiment. The subjects were asked to adjust the level of warning sounds so that they are clearly audible or just audible depends on the instruction. Results of the adjustments are presented and compared to current recommendations for sound levels of warning signals in quiet vehicles.