The international standard ISO 20189

The international standard ISO 20189 describes how different furniture products must be evaluated and declared with regard to acoustic performance and with a focus on the end user. It describes which furniture can be evaluated with sound absorption factor, sound absorption area per object and which types of screens can be evaluated with sound reduction.

The intent of the standard is that products that are not used in practice as large surfaces should be evaluated with their sound absorption area per object. Only objects larger than 10 square meters can be declared using the absorption factor. This means that individual objects cannot be evaluated using absorption classes.

The same applies to sound reduction which can only be used for declaring floor-standing screens. Table screens cannot be declared with sound level reduction as they are too low in effective screen height.

The absorption area per object is evaluated in the individual octave bands 125, 250, 500, 1000, 2000 and 4000 Hz, and the values ​​are calculated from the sound absorption area in the corresponding third band.