Cube-shaped sound-insulating enclosures: Experimental tests and calculation models

Abstract

The research described in the article concerns sound-insulating enclosures used for sound sources imitating a noisy machine or device. It is a continuation of experimental tests and modelling studies conducted previously on a prototype test stand, in which the enclosure walls measured 0.7 m × 0.7 m. The main aim of the research was to estimate the acoustic efficiency of the enclosures through experimental testing on a new stand with walls measuring 0.55 m × 0.55 m, conducted under conditions similar to those found in an industrial facility. Tests conducted for five wall types of varying thicknesses, made of materials such as steel, aluminium, and plexiglass, enabled the development of a calculation model for insertion loss, which could be used on the basis of the material data for the enclosure walls. The model was validated during further experimental tests covering four additional material variants and a high correlation of the results was obtained. The influence of the calculation model used for the enclosure wall’s transmission loss on the insertion loss result was also investigated. The results of the experimental tests and modelling studies were also compared to those obtained for a larger enclosure made of the same wall materials. The research described in the article may have practical applications in the selection of walls of cube-shaped enclosures and in estimating their effectiveness in a cost-free manner, assuming that the appropriate material data is used in the calculations.