Transmission, Absorption and Reflection
Three terms used for describing the resultant distribution of acoustic energy impinging on a boundary such as a wall partition.
Transmission describes the acoustic energy that passes through the partition.
Absorption is the mechanical conversion of energy into heat as the sound wave does ‘work’ on the partition. This is the energy that is lost by the sound wave upon interaction with the interface. With the case of absorption panels situated on a surface, the deeper the absorption material, the more it will attenuate low frequencies – this is evident in comparison of the absorption coefficients for our absorption panels – the depth of the panel becomes more and more comparable to the wavelength of the low frequency sound waves leading to greater mechanical interaction.
Reflection describes the acoustic energy that is deflected by the object.
Incident sound energy = Transmitted + Absorbed + Reflected energy