Showing papers in "Applied Acoustics in 2010"

TL;DR: In this paper, a new method to detect leakage in a water-filled plastic pipe is proposed, where a leakage signal-signature in time domain is first captured by monitoring the Short Time Fourier Transforms (STFT) of acoustic emission signals over a relatively long time-interval.

TL;DR: In this article, the main requirements for airborne and impact sound insulation in 24 countries in Europe are described and discussed, and the comparison shows considerable differences in terms of descriptors, frequency range and level of requirements.

TL;DR: In this paper, an indirect method based on a three-microphone impedance tube setup was used to determine the non-acoustic properties of a sound absorbing porous material, which was applied to four different sound absorbing materials and results of the characterization are compared with existing direct and inverse methods.

TL;DR: In this article, the structural and acoustic responses of a submarine under harmonic force excitation were analyzed by solving the cylindrical shell equations of motion using a wave approach and the conical shell equations with a power series solution.

TL;DR: In this article, the sound attenuation performance of micro-perforated panels (MPP) with adjoining air cavity was investigated for a plenum, and it was demonstrated that a MPP can be modeled as a transfer impedance and partitioning the adjoining cavity enhances attenuation to acoustic modes that propagate transverse to the MPP.

TL;DR: In this article, the influence of aggregate type on the mechanical and acoustic characteristics of porous concrete is systematically investigated, and a sound absorbing porous concrete with a maximum absorption coefficient of approximately 1.00 is developed, and the minimum absorption coefficient is shown to be more than 0.60 with a frequency of 400-Hz or above.

TL;DR: In this article, a perforated plate (PP) was added to the multilayer structure to further enhance the sound absorption in this area, and analyses were accomplished through three PP modeling approaches (Allard, Beranek and Ver, Atalla and Sgard) and Allard Transfer Function (TF) method.

TL;DR: Two traffic representations for the assessment of urban noise frequency spectrum are compared: a static one, based on mean vehicle speeds and flow rates, and a dynamic one, which considers vehicle interactions along the network.

TL;DR: In this paper, a large scale survey in Europe and China as well as corresponding laboratory studies, the influencing factors on the sound preference evaluation, considering social, demographical, physical, behavioural and psychological facets, have been systematically examined based on statistical analyses for each of the 19 case study sites.

TL;DR: In this article, a comparative study of requirements for sound insulation between dwellings revealed significant differences in descriptors as well as levels, and a suggestion to harmonize airborne and impact sound insulation descriptors in building regulations is given.

TL;DR: In this article, a dual Helmholtz resonator with a pair of cylindrical necks and cavities connected in series (neck-cavity-neck-Cavity) is analyzed in terms of a lumpedparameter theory.

TL;DR: In this article, the authors characterize the acoustical behavior of bituminous mixtures fabricated with recycled rubber crumb and compare them with a reference mixture without crumb rubber.

TL;DR: An extensive survey and an algorithm taxonomy is presented and each algorithm is reviewed according to a set of criteria relating to their success in application, concluding that none of these algorithms fully meets these criteria.

TL;DR: In this article, the effect of high temperatures on absorbing properties of fibrous metal materials was studied by using Dup‘ere's model and Tarnow's model to calculate effective density and effective bulk modulus.

TL;DR: In this paper, the effect of different boundary conditions on both baffled and unbaffled results is demonstrated by comparing the results for guided boundaries with those for simply supported boundaries, and the difference is shown between the result for a baffled plate and an unbaffed plate.

TL;DR: In this paper, adaptive filtering techniques are employed to enhance diesel fuel injector needle impact excitations contained within the air-borne acoustic signals, which are remotely measured by a condenser microphone located 25 cm away from the injector head, band pass filtered and processed in a personal computer using MatLab.

TL;DR: In this paper, a quantification model concerning overall dissatisfaction from multiple noise sources in residential buildings and underlying assumptions were presented, which can be used to assess the associated overall dissatisfaction of the indoor noise environment on the basis of the level of individual sources.

TL;DR: In this article, the authors investigated the relationship between Helmholtz-resonance absorption and panel-type absorption including the effects of eigenmode vibrations of the panel and found that panel type absorption due to a mass-spring resonance of a panel and a back cavity has a trade-off relationship with the HRS with respect to the perforation ratio.

TL;DR: In this paper, an experimental and numerical study of friction-induced vibrations of a system composed of two beams in contact is proposed, where the experimental system exhibits periodic steady state vibrations of different types.

TL;DR: In this paper, the sound absorption characteristics of a double-leaf MPP absorber backed by a rigid wall are analyzed by wave theory using Helmholtz-Kirchhoff integral formulation to obtain a strict solution.

TL;DR: In this paper, a passive acoustic method for estimating the density of echolocating cetaceans that dive synchronously, based on isolation of dive starts using a field of distributed bottom-mounted hydrophones, is presented.

TL;DR: The sound of horns contributed a definite impact of 0–4 dB on noise exposure in Hanoi and Ho Chi Minh City, where noise levels decreased with the absence of horn sounds, and differences in the characteristic traffic noise of Vietnam and Japan.

TL;DR: In the Southwestern Indian Ocean, one year of continuous acoustic data from calibrated hydrophones maintained by the International Monitoring System provided data on blue whale calls from two subspecies Antarctic and pygmy blue whales.

TL;DR: In this article, the effect of point-and line-connections in double-leaf constructions in a transfer matrix setup was investigated and a simple method was proposed to account for the effect.

TL;DR: In this paper, the authors present a new guide (Methodological Guide, Vehicle Noise emissions, to be published), which addresses the road surface influence on tyre/road noise, and the emission values are now expressed through the contributions of a power unit component, function of traffic speed, traffic flow type and road declivity, and of a rolling noise component.

TL;DR: In this paper, the tail pipe noise from a commercial automotive muffler was studied experimentally and numerically under the condition of wide open throttle acceleration in the present research, and the results of simulation are in good agreement with experimental results at the 2nd order of the engine rotational frequency.

TL;DR: In this article, a coupled edge-based smoothed finite element method (ES-FEM) and face based smoothed FEM was proposed to solve the structural acoustic problems.

TL;DR: In this paper, a numerical case for eliminating broadband steam blow-off noise using multi-chamber plug-inlet mufflers in conjunction with a GA as well as a numerical decoupling technique, all within a space-constrained pressure drop, is introduced.

TL;DR: In this article, a simple prediction model has been derived for the average A-weighted noise level due to many people speaking in a room with assumed diffuse sound field, and a guide for the recommended minimum absorption area per person in eating establishments is provided.

TL;DR: In this paper, the authors provide guidance on hazard identification, exposure assessment, exposure response relationships and risk estimation for assessing the effects of traffic noise on sleep, based on the current literature.