Showing papers in "Applied Acoustics in 2013"

TL;DR: The Positive Soundscape Project (PSP) as discussed by the authors found that soundscape perception is influenced by cognitive effects such as the meaning of a soundscape and its components, and how information is conveyed by a soundscapes, for example on the behaviour of people within the soundscape.

TL;DR: In this article, a Principal Component Analysis (PCA) was conducted to decompose descriptors of the urban soundscape into two independent emotional dimensions, i.e., calmness and vibrancy.

TL;DR: In this article, the authors developed and tested a Perceived Restorativeness Soundscape Scale (PRSS) to assess perceptions of a soundscape's potential to provide psychological restoration.

TL;DR: In this article, an experimental analysis on the aeroacoustic features of propellers aimed at the propulsion of small unmanned aerial vehicles is presented. And a numerical analysis based on the compact formulation of the Ffowcs-Williams/Hawking equation and a simple model for the broadband noise, is presented and discussed.

TL;DR: In this paper, the authors used non-linear theory for cylindrical shell to derive motion equation under simply supported boundary condition and solved the motion equation by using Galerkin method that resulted in a system of nonlinear equations with 6 degrees of freedom.

TL;DR: In this article, the free vibration of axially inhomogeneous beams with various end conditions was analyzed and the characteristic equations were derived in closed form for exponentially graded beams, where the gradient has a strong influence on the frequency spectrum and the natural frequencies noticeably depend on the variation of the gradient parameter and end support conditions.

TL;DR: In this article, an acoustic energy harvester is introduced that uses a quarter-wavelength straight-tube acoustic resonator with polyvinylidene fluoride (PVDF) piezoelectric cantilever beams placed inside the tube.

TL;DR: In this paper, a soundscape assessment method that is suitable for the automatic categorization of binaurally recorded sound in urban public places is presented, based on an automatic clustering algorithm based on multi-parameter analysis by 13 acoustical parameters used as similarity measures, on a large set of sound recordings.

TL;DR: The Hilbert–Huang transform is used for the extraction of new relevant damage descriptor to be adopted for Acoustic Emission (AE) pattern recognition in order to help understanding the damage process.

TL;DR: An approach traditionally used in product development and manufacturing quality – The Kano Model is proposed, which shows how adapting an approach previously used in automotive sound quality can be adapted for urban soundscapes.

TL;DR: In this paper, a range of perceptual, psycho-acoustic and acoustical properties were examined using principal components analysis (PCA) and multiple regression (MRC) methods.

TL;DR: Cognitive performance during irrelevant speech: effects of speech intelligibility and office-task characteristics as discussed by the authors, in the context of irrelevant speech, was found to be positively correlated with the intelligibility of speech.

TL;DR: In this paper, a domain decomposition technique for solving vibration problems of uniform and stepped cylindrical shells with arbitrary boundary conditions is presented, where the displacement components of each shell domain are expanded in the form of a double mixed series: Fourier series for the circumferential variable and polynomials/series for the axial variable.

TL;DR: In this paper, the prediction accuracy of the sound absorption coefficient of these seven published impedance prediction methods was determined by comparing the predicted and the measured absorption coefficients of 82 mineral wool configurations within 100 and 3150 Hz.

TL;DR: In this article, the authors investigated the damping properties of rectangular plates containing tapered indentations of power-law profile, with the centers of the indentations covered by a small amount of absorbing material.

TL;DR: In this article, a cellular acoustical metamaterial consisting of a periodic arrangement of unit cells consisting of plates held in a grid-like frame is proposed to yield enhanced low frequency transmission loss.

TL;DR: Distinctive relationships were found between physiological measurements and the subjective estimates of the pleasantness of the presented sound-clips, which were greater in males than in females.

TL;DR: In this paper, a non-flat plate serration was used to reduce the airfoil trailing edge self noise by employing nonflat plate type trailing edge serrations, which offers better structural strength and integrity, as well as a more straightforward manufacturing process compared to the conventional flat plate type serrations.

TL;DR: In this article, the authors used micro-perforated panels (MPP) with ultra-micro perforations based on MEMS technology and measurement of their normal absorption coefficients were carried out.

TL;DR: In this paper, an exact series solution for the vibration analysis of circular cylindrical shells with arbitrary boundary conditions is obtained, using the elastic equations based on Flugge's theory, which can be universally applied to shells with a variety of different boundary conditions, without the need of making any corresponding modifications to the solution algorithms and implementation procedures as typically required in other techniques.

TL;DR: In this paper, the authors determined the phenomenological parameters that impact the sound transmission of vegetated roofs and found that the increased transmission loss was due to the installation of roof material layers on the reference roof, at the field site (wood frame construction) and at a field laboratory (light-weight metal construction).

TL;DR: In this article, an extensive literature survey is presented of noise source characteristics in the ISO 362 vehicle pass-by noise test and a ranking of the noise source contributions is established.

TL;DR: In this article, the thermal and acoustic properties, sound absorption coefficient at normal incidence and static flow resistivity of aluminium foams manufactured by means of the infiltration process were analyzed and the important role of the cell diameter in fixing the physical properties of these materials was revealed.

TL;DR: In this paper, a muffler with an interconnecting hole on the tail pipe was proposed to improve the low-pass filter attenuation performance of low frequency and middle frequency.

TL;DR: The results demonstrated a measurement system and predictive method that offers potential to explore more suitable noise parameters that correlate the human response to traffic related noise and to improve the understanding of the effect of traffic flow characteristics on the minute by minute variation in noise levels in busy urban streets.

TL;DR: A stochastic dynamic traffic noise prediction model based on noise curves for vehicle classes and their speed is presented, which showed a slightly better fit than was found in four deterministic models that are highly internationally recognized.

TL;DR: In this article, the authors evaluated the acoustic performance of conventional and low-height gabions noise barriers and found that the effectiveness of low height barrier is significant for receivers of limited height and the insertion loss values can reach 8 dB(A) behind the barrier.

TL;DR: In this article, two shear flow corrections, based on acoustic ray theory and convected wave equation, were proposed to estimate the apparent source shift in an anechoic wind tunnel.

TL;DR: In this article, a new measurement procedure to obtain transmissibilities for application in a two-step transfer path analysis is presented, where an external excitation, for instance by means of a non-instrumented hammer, is used to bring the structure into vibration.

TL;DR: In this article, the authors proposed a model to predict the sound unit durations and frequency formants of humpback whales using measurements of the trachea, laryngeal sac, and nasal cavities.