Showing papers in "Applied Acoustics in 1986"

TL;DR: In this paper, a method of calculating the overall acoustic impedance of multiple layered absorbing systems is presented, and good agreement between measured (impedance tube) and computed impedances has been obtained.

TL;DR: In this article, a model was described for the calculation of the weighted airborne sound insulation between dwellings, which is based on the same input data as for airborne sound, and a new quantity however is the floor admittance.

TL;DR: In this paper, the authors assess the methods of predicting speech intelligibility (SIL, AI, STI, SNA), taking into account both the speaker's sound level and the speech intelligible at the hearer's position.

TL;DR: In this paper, a finite element algorithm was used to determine the fundamental frequency coefficient of a point-supported printed circuit board (PCB) with different shapes and support arrangements. But the analysis was limited to the case of clamped and simply supported points.

TL;DR: In this paper, a direct measurement of the structure-borne sound intensity has been tried on thin-plate constructions in laboratory set-ups, and the results appear to be promising even on relatively thick and heavy concrete walls with normal junctions to the surrounding constructions.

TL;DR: In this paper, it is shown that the calculated sound pressure level is higher than expected on the basis of sound intensity, and the use of sound pressure levels measured close to a source leads to a sound power estimate which is too high.

TL;DR: The sound intensity method as discussed by the authors allows selective determination of sound reduction indices for test objects surrounded by flanking surfaces, provided the measurement surface in the receiving room is defined in such a way that it encloses nothing but the test object.

TL;DR: In this paper, a simple Rayleigh-Ritz methodology and a finite element algorithmic procedure were used to solve the title problem of simply supported and clamped plates with free, square holes located at the middle of a plate edge.

TL;DR: In this paper, the authors describe an experimental investigation carried out by the authors at the Institute of Applied Mechanics on the title problem, which appears, at this point, that the two dynamic absorbers solution is a promising one for this very important and troublesome technological situation.

TL;DR: Bjergsted concert hall in Stavanger, Norway, was opened in 1982 as a multi-purpose hall, but primarily intended for concerts as mentioned in this paper. The hall has been rebuilt from an old dome-shaped exhibition hall.

TL;DR: In this article, the results of computer simulation experiments on the amplitude distribution of sine waves of equal amplitude combined with random phasing are set the experimental results into a theoretical context, and it is shown that both experimental results and theoretical predictions are in satisfying agreement.

TL;DR: This paper presents for the first time a fairly simplified identification method applicable to the actual situation of a sound insulation system under the introduction of a time series system model as seen from the probabilistic viewpoint.

TL;DR: In this paper, the reduction in peak sound pressure level of artillery noise due to diffraction over hills has been measured and compared to the results of a pulse diffraction theory, and it was found that Kirchoff boundary conditions most accurately predict the results.

TL;DR: In this paper, an experiment was conducted to measure the characteristics of flow noise in a bounded system with forced circulation, where cylinders of various diameter and pitch perpendicular to the flow were inserted in the conducting rectangular ducting.

TL;DR: A survey of complaints received by local authorities in Scotland has shown that complaints about amplified music are increasing and constitute about 25% of the total number of complaints concerning noise as mentioned in this paper, mainly about discotheque noise.

TL;DR: In this paper, weiblichen und mannlichen studenten wurden in je 12 aufeinander-folgenden Nachten im Labor aufgezeichnet.

TL;DR: In this article, an approximate solution of the large deflection axisymmetric response of cylindrically orthotropic thin circular plates resting on Winkler, Pasternak and non-linear Winkler foundations is presented.

TL;DR: In this paper, an approximate solution to the title problem is presented, and the results obtained by the Galerk in method and using polynomial approximations are compared with values obtained by means of a finite element algorithm.

TL;DR: A digital system for evaluating the acoustic properties of enclosures can display the build up or decay processes of a room from the results of a single experiment by using an impulsive sound source by an approach based on the integrated impulse method.

TL;DR: New mathematical models relating vehicular noise to various traffic and road layout characteristics are developed, based on large-scale measurements undertaken in a typical Greek urban centre, Thessaloniki, and conclusion are drawn concerning the relative importance of the various parameters in explaining the levels observed.

TL;DR: In this article, the modal frequencies and nodal positions of a vibrating beam with a sliding end (zero slope and shear) were investigated and accurate analytical approximations were derived and compared with exact numerical values.

TL;DR: In this paper, the authors use the point mobility to estimate the modal density of cylindrical piping systems, which is especially suited at frequencies below the ring frequency where theoretical estimates do not account for the grouping of structural modes that occurs.

TL;DR: In this paper, the propagation of acoustic waves and energy absorption in a medium of air containing suspended water droplets have been investigated experimentally, and it has been found that an increase in atomisation pressure or mass flow ratio reduces the size of droplets, thus yielding higher noise reduction.

TL;DR: In this article, a simple phonetic guide was devised for those who wish to learn English as a foreign language, which can help a learner adjust his tongue hump position and the constriction in his vocal cavity so that he can accurately pronounce any English vowel.

TL;DR: In this article, the optimal design of an impact absorber for a machine mounted on a floor system is described, where the floor is considered to be a plate-like structure and the optimal tuning and damping ratios of the absorber are determined by minimizing the mean squared displacement (velocity, acceleration) response of the machine.

TL;DR: In this article, a reale Luftschallverhalten eines kleinen Zweitaktmotors with Kurbelkammerspulung (V H = 70 cm 3, P e = 3·0 KW bei 7500 l/min) wird mit Hilfe eines linearen Ersatzmodells beschrieben.

TL;DR: A microcomputer databank and retrieval system developed at the Centre for Building Studies, Concordia University, for the rapid compilation or searching of information concerning the sound transmission loss of walls and windows, and their defining physical parameters is described.

TL;DR: A wealth of information exists in the published literature, revealing the various aspects of vibration environment on human activities as discussed by the authors, and many industrial nations have formulated standardized procedures to safeguard the wellbeing of their working populations, by preventing vibration pollution levels reaching various parts of the body by various means.