At times we all want to live and work in a quiet environment. Acoustic requirements in practice are often versatile and individual. In most cases effective solution concepts must be found that bring important area and building acoustics together. In most cases very rigid standards must be observed.
Acoustic correction is a necessary part of creating good indoor environments.
Area acoustics examines what effect the interior finishes of an area have on the planned area utilization. Different known values are used for the evaluation of the acoustic qualities of an area.
The reverberation time is the oldest and best known calculation method in the field of acoustics. It is declared in seconds and is defined as the time span for a sound print in an area to decrease by 60 dB after cessation of the sound source
Sound absorption describes the reduction of sound energy. The degree of sound absorption defines the relationship of reflected to absorbed sound energy.A value of 0 of corresponds to total reflection – a value of 1 to complete absorption. If the degree of sound absorption is multiplied by 100, one gets the percentage sound absorption. α = 0.75 means 75% of sound absorption, accordingly 25% of sound reflection remains.
Absorption Class αw-Value [-]
A 0.90; 0.95; 1.00
B 0.80; 0.85
C 0.60; 0.65; 0.70; 0.75
D 0.30; 0.35; 0.45; 0.50; 0.55
E 0.15; 0.20; 0.25
Non classified 0.00; 0.05; 0.10
Noise Reduction Coefficient NRC:
The American Standard ASTM C 423 corresponds to International Standard ISO 354. However, ASTM C 423 contains the regulation of an additional singular statement. The singular value NRC is determined as follows: