The primary issue in evaluating airborne sound insulation lies in quantifying the sound energy emitted by the barrier. This is typically accomplished by measuring sound pressure levels in sending and receiving rooms and acoustic absorption within the receiving room. When significant fluctuations in sound pressure levels occur within a reverberation room, it indicates the presence …
Tag: sound transmission loss
Sound insulation performance of cube-shaped enclosure
The subject of the research described in the article are the sound insulating properties of a cube-shaped enclosures, the walls of which are made of plates of homogeneous materials and two-layer baffles. As an enclosure for an omnidirectional sound source imitating a noisy machine or device, a prototype test stand for testing the acoustic properties …
Testing the airborne sound insulation of reduced size baffles with different dimensions
The article discusses the requirements for determining airborne sound insulation according to ISO 10140-2, which involves measuring sound pressure levels in the source (L1) and receiving (L2) rooms, as well as reverberation time measurements in the receiving room. The size of the free test opening and the equivalent sound absorption area in the receiving room …
Determination of sound insulation properties of homogeneous baffles using Finite Element Method
The basic parameter of materials used in constructional solutions of anti-noise protection, is sound insulation, which can be determined in laboratory conditions and also using theoretical models. The use of numerical methods in the form of the Finite Element Method to calculate the mechanical impedance of a baffle and then the sound insulation of homogeneous …
Comparative Analysis of the Acoustic Properties of Granular Materials Determined with the Use of Impedance Tube
The results of acoustic property tests for six types of granular materials: perlite, vermiculite, active coconut carbon, rubber granulates, pumice and wood chips, which can be used in noise protection structures, are shown in the article. The characteristics of the normal incidence sound absorption coefficient and the normal incidence sound transmission loss for material specimens …
Using MLS Methods in Laboratory Measurement of Airborne Sound Insulation
Following the requirements of ISO 10140, to determine the acoustic insulation, measurements of the sound pressure levels in the source (L1) and receiving (L2) rooms and the reverberation time measurements in the receiving room (T) should be performed. However, the standard does not indicate the measuring signal to be used for the measurements. Various measurement …
Experimental Tests of the Acoustic Properties of Sound-Absorbing Linings and Cores of Layered Baffles
The article presents the results of research on the acoustic properties of materials used as sound- absorbing linings and cores in baffles of anti-noise protection. Using an impedance tube the spectral characteristics of the normal incidence sound absorption and sound transmission loss indices of 12 specimens of mineral wool with different density and thickness were …
Experimental Study and Prediction of Insertion Loss of Acoustical Enclosures
The article presents the results of an experimental study and calculations, using theoretical models, of the insertion loss of acoustical enclosures. The research used a developed prototype stand for testing acoustical enclosures. The sound power levels of the source without and with the enclosure, needed to determine the insertion loss, were determined by the approximate …