The optical absorption coefficient of the sample is quantified from spectra of the measured photoacoustic signals.

Using an image receptor with a greater attenuation coefficient

An acoustical ceiling tile having an improved sound absorption value and having a dual layer of acoustical materials.

A material's sound absorbing properties can be expressed by the sound absorption coefficient, alpha, as a function of frequency, where alpha ranges from 0 (total reflection) to 1.00 (total absorption).

A material’s sound absorbing properties are expressed by the sound absorption coefficient, α, (alpha), as a function of the frequency. α ranges from 0 (total reflection) to 1.00 (total absorption).

Sound absorption is measured using the sound absorption coefficient alpha (α), which has a value between 0 and 1.00.

The absorption diagrams show the practical sound absorption coefficient, αp in accordance with the international standard EN ISO 11654.

The surface layer has a high mineral wool content which provides improved sound absorption values with or without perforating or fissuring the tile.

For instance, if a material reflects70% of the sound energy incident upon its surface, then its Sound Absorption Coefficient would be 0.30.

For instance if a material reflects 70% of the sound energy incident upon its surface, then its Sound Absorption Coefficient would be 0.30.

With the facing sheet the air flow resistance of the laminate is greater than the air flow resistance of the substrate and the laminate exhibits a higher sound absorption coefficient than the sound absorption coefficient of the substrate.

This model has a good absorption coefficient in the mid-low spectrum, concentrated within 400Hz to 1.25kHz, which is very important to improve the absorption in the sound frequencies of the common noise.

If the surface fails to comply with the residual voids content requirement, the surface is acceptable only if its sound absorption coefficient α <= 0,10.