What is Sound Absorption?
Sound absorption is defined, as the incident sound that strikes a material that is not reflected back. An open window is an excellent absorber since the sounds passing through the open window are not reflected back. Conversely it makes a poor sound barrier. Painted concrete block is a good sound barrier but will reflect about 97% of the incident sound striking it. When a sound wave hits an acoustical material the sound wave causes the fibers or particles of the absorbing material to vibrate. This vibration causes tiny amounts of heat due to the friction and thus sound absorption is accomplished by way of energy to heat conversion. The more fibrous a material is the better the absorption; conversely denser materials are less absorptive.