How effectively a material absorbs sound depends on its density, porosity, and thickness. Soft and porous materials, such as foam, felt, or fibre, are particularly good at absorbing sound because sound waves can penetrate the material and lose energy through friction.
The sound absorption coefficient α is used as a measure of a material's ability to absorb sound. It is a dimensionless quantity that indicates the ratio between absorbed energy and the sound energy incident on the absorber. Theoretically, α ranges from 0 to 1, corresponding to no absorption and complete absorption, respectively. For all absorption materials, α varies with the frequency of the sound.
Sound absorption is used in many contexts – for example, in vehicles to reduce cabin noise, in buildings to create better acoustics in rooms and offices, and in public transport and energy facilities to reduce disruptive noise levels and improve the working environment.
Antiphon offers sound-absorbing materials under the name antiphon® LA. antiphon® LA™ is a family of foam materials used in applications to absorb airborne sound. The components are cut or stamped into shapes and sizes that are best suited to the final application and are used for sound absorption.
The components are placed on surfaces to capture sound waves in the air and convert the waves’ energy into heat, rather than allowing them to be reflected back. The absorption capacity depends, among other factors, on thickness and frequency – thicker materials generally provide better absorption at lower frequencies.