Excess noise and continuous, disturbing noise are harmful. That is why the effect of noise needs to be kept down to a minimum. Particularly relevant in this context are sound protection in residential buildings and the shielding of road noise (noise barrier walls). Depending on the type of noise source, its location with respect to the area to be protected and the path via which the sound is transmitted, various sound protection measures are needed. Basically, a distinction is made between measures aimed at sound absorption via sound dissipation – meaning that the acoustic energy is converted into other forms of energy (usually heat) – and those used for sound reduction via reflection of the sound waves. Makrolon® mono and multi sheets belong to the second category.
A distinction is made between the mean sound reduction index, Rm, and the weighted sound reduction index, Rw.
Rm is determined according to DIN 52210, Part 1, i.e. the sound reduction is measured with respect to the frequency and then the rithmetic mean value is calculated.
For the practical assessment of the sound reduction, however, the "weighted sound reduction index", Rw, which takes account of the subjective effect for the various frequencies, is used.
|Subjective loudness||Sound pressure level in
|Painful||140||Jet aircraft takeoff in immediate vicinity|
|Intolerable||120||Pneumatic hammer at 1 m|
|Very noisy||90||Machine Shop|
|Moderately noisy||80||City motorway|
|70||Car traffic noise at approx. 50 km/h|
|20||Ticking of a clock
|0||Threshold of hearing|