What is the difference between sound insulation and sound absorption?
When airborne sound arrives at the surface of a wall or floor, some of it is reflected back as an echo, and some of it is transmitted. The remainder is converted into other forms of energy within the material, principally heat. This is known as sound absorption. When airborne sound arrives at one surface of, for example, a floor, some of it is reflected back as an echo, some of it is converted into other forms of energy within the material of the body, and the remainder is transmitted through the material to be radiated as airborne sound on the other side, but at a reduced level. The degree to which this reduction takes place is the sound insulation provided by the floor.