Sound absorption means the process of reducing sound energy, particularly (but not necessarily), by conversion to heat. ‘Absorbing’ is equivalent to ‘swallowing’ or ‘sucking in’. The term is used in a very similar way as is ‘sound dissipation’ and ‘sound attenuation’. The distinction given to dissipation is that the transformation of sound into other energy is understood, in particular heat; while in absorption other modes of the ‘disappearance’ of sound can be included (see sound absorption level). Sound damping, on the other hand, means any type of reduction in the sound intensity – which does not necessarily mean reducing the sound energy – for example by divergence, or by distributing the sound energy over a larger area. Two quantities, the absorption coefficient and the absorption level, are used for the quantitative determination of sound absorption.
For light ceilings, textile materials can be used which have a sound-absorbing surface. As a rule, this surface property is achieved by using a special woven structure or by perforation.