Showing papers in "Applied Acoustics in 1982"

TL;DR: A method of determining a quantitative measure of the ray tracing technique error, which results from replacing a wave structure of an acoustical field by a grain one, is presented.

TL;DR: In this article, the acoustic ray image theory is developed to predict relative sound levels along a corridor or in adjacent rooms caused by a sound source in the corridor, from experimental results in full-size corridors and in an acoustic scale model, general comments about the behaviour of sound in corridors are made.

TL;DR: In this article, the authors describe a propagation model for calculating neighbourhood noise from open-air industrial plants such as oil refineries and petrochemical plants, based on a preliminary model derived from a comprehensive survey of the literature on noise propagation.

TL;DR: In this paper, a simple method to measure structure-borne sound transmission is described, where the level difference in the acceleration between two structural elements using a plastic headed hammer as a noise source is made.

TL;DR: In this paper, an analysis of the noise problem produced when the application of standard acoustic treatment to a roof-mounted diesel generator failed to meet the design criterion was presented, and the problem was diagnosed as excessive vibration reaching the building due to the excitation of a resonance of the supporting structure.

TL;DR: In this paper, a new method to reduce traffic noise by means of an invisible wall has been investigated both theoretically and experimentally, and a formula was derived for the frequency dependent impedance of an infinite structure of parallel ribs on an impedance boundary.

TL;DR: In this paper, the authors developed an acoustic traffic signal for blind pedestrians, which consists of 200 ms pulses at a repetition rate of 2·5 Hz and 400 ms pulses with an average rate of 0.5 Hz.

TL;DR: In this paper, sound levels in rooms adjacent to a corridor, produced by the transmission of sound through the corridor from another room, can be predicted by using an acoustic scale model to show how the physical parameters of the corridor affect the transmission into, out of and along the corridor.

TL;DR: In this paper, the use of sampling techniques for the measurement of environmental noise is discussed and used to illustrate how the further development of such techniques could aid future research and noise control initiatives.

TL;DR: In this paper, the effect of the mounting frame on the sound field is reduced by shielding it from the sound fields, which reduces the amount of sound transmitted through the wall specimens.

TL;DR: A survey of values of the inversion index (II) in a number of concert halls reveals large variations in the energy balance between direct sound energy and early reflection energy as discussed by the authors.

TL;DR: The method used to obtain the wavespeed from low frequency pulses is very simple and the results are accurate, making the method suitable for many applications.

TL;DR: In this article, a method of calculating sound build up, steady state and sound reduction phenomena from the impulse response of rooms is presented, where the noise components of both the testing signal and the room response are omitted and wave phenomena occurring in the room are also neglected.

TL;DR: In this article, measurements were made on a 1:20 scale model of a large aperture in a building and the experimental results were compared with the predictions of a simple theoretical model.

TL;DR: In this article, a method of predicting sound pressure levels from an explosive source has been developed by the author to assist in the control of artillery firing at Larkhill, where the RMS error was less than 6 dB for levels of 100 dB or more.

TL;DR: In this paper, sound attenuation by narrow forest belts, under quasi-line source conditions, was investigated and experiments were conducted on windbreaks of Casuarina and Eucalyptus belts, along three sites at Nobria.

TL;DR: In this article, the authors describe and evaluate six alternative methods for sound insulation between dwellings using a simple meter giving a direct reading of the decay time of the reverberation in the room.

TL;DR: In this article, a simple analytical approach which allows for the prediction of the natural frequencies of circular plates with stepped thickness is proposed, which can be used in the construction of high frequency transducers.

TL;DR: In this paper, an exploratory study whose main aim was to develop equations for the prediction of low frequency traffic noise scales (from traffic parameters) is described, and a method for determining low frequency scales using simple instrumentation is described.

TL;DR: In this article, the sound insulating characteristic in porous ceramic Al 2 O 3 -SiO 2 has been treated on the basis of Beranek's theoretical treatment of an acoustical material.

TL;DR: In this article, the measured and theoretical values of the sound transmission loss at low frequencies are made to reach good agreement by the introduction of a correction factor, which is one of the disadvantages of statistical energy analysis.

TL;DR: The essential features of a general purpose interface unit are described and an explanation is given of how this unit can be used to transfer digitised samples of audio signals to 3032 user memory for software processing.

TL;DR: In this paper, the authors present ten member states of the EEC and the prospective members states of Spain, Portugal and Turkey, and the aim of this survey is to update a survey made in 1975 on scientific standards and legislation for the protection of workers from hazardous levels of noise in the workplace.

TL;DR: In this paper, a social study was undertaken of the subjective responses to aircraft noise of 909 Chinese living near or adjacent to the flight-paths of aircraft landing at, or taking off from, the international airport of Kai Tak.

TL;DR: In this paper, musical subjective criteria are arranged in a personal order of preference, with an attempt at describing their physical counterpart, in the light of recent measurements of the fluctuations in the frequency spectrum caused by the filtering of sound waves by the outer ear.

TL;DR: A new approach to environmental noise measurement and assessment is proposed, based on the exploitation of the digitally recorded evolution of short term L eq which enables the a posteriori performance at low cost of any investigation, checking of interpretation, or automatic output of tables and graphs.

TL;DR: In this article, the authors solved the title problem in the case of an orthotropic plate with three edges elastically restrained against rotation whilst transverse displacement is prevented, where the Rayleigh-Ritz method was used to derive an approximate fundamental frequency equation.

TL;DR: In this paper, the effect of a reflecting plane on the power radiated by a point source was investigated, where a corona-type monopole was used in the experimental setup.

TL;DR: In this article, a study of the barrier attenuation produced by 40 different finite garden fences shielding suburban homes from traffic noise was conducted, and an empirical relationship between the results was obtained, which indicated that the attenuation measured in terms of L 1, L 10 or L eq generally agrees within ± 1 dB(A) for a given barrier.