Possibilities of Evaluating the Effectiveness of Noise Barriers in Slovakia

Abstract

This paper presents environmental acute problems from increasing noise levels caused by automobile and rail transport. Noise barriers are considered to be an effective element in reducing noise in densely populated urban areas. However, do these barriers have the correct height, shape, material design, and construction? In the materials and methods, the basic characteristics of noise barrier, sound absorption, and sound insulation are described. Further, measurement methods of the insertion loss of outdoor noise barriers of all types using the direct and indirect method according to standard ISO 10847 and the Adrienne method according to standards EN 1793-5 and EN 1793-6 are presented. The measurement results of insertion loss of the selected noise barrier obtained by the indirect method showed a value of 19.1 dB(A) of insertion loss. This result was compared with simulation by our own software based on the CNOSSOS methodology, giving value of 19.6 dB(A), which is a good correlation. The Adrienne method was used for determination of the airborne sound insulation index of another noise barrier, giving a value of the single-number rating of the sound insulation of the barrier of 28 dB. In discussion, according to EN 1793-2, this value assigns an insulation index of category D3, which means that the barrier is high quality and has satisfactory airborne sound insulation. The advantages and disadvantages of both methods according to STN ISO 10847 and STN EN 1793-6 were discussed. We concluded that the main advantage of the method Adrienne—TN EN 1793-6 is that it can be used in situ under direct sound field conditions and can directly evaluate the sound insulation index of the whole barrier structure.

Keywords

• road traffic noise
• noise barriers
• noise measurements
• sound reduction
• sound reflection
• insertion loss