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The article presents research studies on the impact of perforation of the outer lining layer of an acoustic panel used for the construction of road noise reduction devices on its absorbing properties. The research included measurements of the reverberation time in the laboratory conditions of diffusion field, on the basis of which the values of sound absorption coefficient as a function of frequency were determined. In addition, for various solutions of acoustic panels based on a corrugated fiber cement board on the top surface and on two types of mineral wool inside the panel, the αw and αp indices as well as sound absorption rating index DLαNRD were calculated. Then, computer simulations were carried out to show the influence of laboratory-determined acoustic parameters of the panels on the acoustic climate in the vicinity of a selected transport system. The key aspects of the modeling process are presented, the characteristics of the noise source and the analysis of the results are described. An important goal of traffic noise modeling is to strive to develop more friendly and sustainable material solutions that will reduce the negative effects of noise on people and the environment. [ABSTRACT FROM AUTHOR]

The article presents the assumptions of traffic intensity for a selected road section, which have been verified on the basis of measurements and data provided from General Measurement of Traffic (GPR). On this basis, simulations of noise ranges were made in the SoundPlan program. The simulations were performed for both predicted and verified traffic. Such simulations in the form of acoustic maps were used to determine the impact of the discrepancy between the assumed traffic intensity and that verified by measurements on noise range and its impact on protected areas and building development in the nearest vicinity. [ABSTRACT FROM AUTHOR]

It is well known that the uncertainty of input data has a great influence on the accuracy of room acoustics simulations. The aforementioned accuracy is significantly influenced by the selection of the acoustic properties of room-delimiting materials. Moreover, simulation errors are attributed to the fact that rooms can be very irregular and sound diffusion can be uneven, and thus sound absorption can be unevenly distributed over the surfaces. Therefore, a very important element is the validation of the simulation model of interior acoustics, even when we use ready-made software dedicated to interior acoustics for the simulation. In the article, the reverberation room model simulated in the ODEON program was subjected to validation. The program is based on a hybrid method combining the ray and virtual source methods. For the validation, appropriate measurements of the reverberation time in that room were carried out. The validation was undertaken using the criterion of correct validation, consisting of comparing the value of the comparison error and the value of the validation uncertainty. [ABSTRACT FROM AUTHOR]

Acoustic studies were carried out in a dome-shaped sacral room of the Pentecostal Congregation in Katowice in Silesia, Poland. The investigated room is used for religious purposes, and in terms of acoustics it facilitates the propagation of speech and musical sounds. In the study, acoustic measurement methods were adopted to assess sound reverberation. The "in situ" method was used to determine sound decay curves, and reverberation time was determined in line with EN ISO 3382-1: 2009, EN ISO 3382-2: 2010. Participants of the services complained about poor reception conditions of verbal and musical sounds and flutter echo in some places of the room. Acoustic studies confirmed the listeners' impressions. The room had long reverberation time. To improve the acoustic parameters of the interior, the application of spray-deposited insulating material was proposed. The selected material was subjected to laboratory tests on sound-absorbing properties. The sound absorption coefficient of the material was determined as a frequency function. Then the material was applied on the inner surface of the dome. Acoustic measurements of the adapted interior were repeated. Based on the measurements, the STI was calculated. In effect, a significant improvement in reverberation conditions of the investigated interior was obtained. [ABSTRACT FROM AUTHOR]