NOISE ABSORPTION COEFFICIENTS ACCORDING TO ISO 11654 STANDARD
A wall in a common room is normally reverberant, that is, it does not have acoustic absorption properties and its weighted acoustic absorption coefficient is practically αw 0
On the contrary, a 100% absorbing material has a coefficient αw 1.00
The coefficients are measured by means of a reverberation room.
measures the frequency-dependent sound absorption in a reverberation room, it is used to measure the practical sound absorption coefficient αp
is the practical acoustic absorption coefficient and it is frequency-related.
measures the weighted sound absorption regardless of frequency with classes going from A
(maximum absorption) to F
(reflection) to which the following indicators in brackets are also attributed:
) if the material is efficient in the low frequency range, e.g. αw
) if the material is efficient in the mid-frequency range, e.g. αw
) if the material is efficient in the high frequency range, e.g. αw
Combinations are possible, e.g. αw
) or αw