The effectiveness of acoustic screens (noise barriers) is very frequency dependent and is primarily related on the one hand to the performance of acoustic insulation panels (characterized by their sound reduction index) as well as when appropriate (for applications other than road noise barriers or railway noise barriers) - to the performance of silencers but also to the number and sizes of cutouts and openings, to sealing imperfections, and to the transmission of bridging noise. Moreover, this performance depends on the screen size and on the relative positioning of the noise source and receiver with respect to the acoustic screen (sound barrier) - and also on the size of the sound source -.
The prediction of the effectiveness of an acoustic screen (noise barrier) can be performed with the simulation software SILDIS®®.
Verifying the performance of a baffle (noise barrier) can be performed (as appropriate) in accordance with ISO 11821 Acoustics - Measurement of the in situ sound attenuation of a removable screen or NF EN 1793-1 Road traffic noise reducing devices. Test method for determining the acoustic performance. Part 1: intrinsic characteristics of sound absorption or NF EN 1793-2 reducing devices road traffic noise - Test method for determining the acoustic performance - Part 2: intrinsic characteristics related to the airborne sound insulation.