Foam cores like XPS are primarily thermal insulators, but they do provide some sound absorption and transmission loss benefits, though they are not specialist acoustic products.
- Sound Absorption: The rigid, closed-cell structure of XPS is not highly effective at absorbing airborne sound (like open-cell foam or fiberglass). It has a relatively low Noise Reduction Coefficient (NRC).
- Impact Sound/Transmission Loss: It can be effective in floating floor systems to dampen impact noise (footsteps) because of its compressive strength and resilience. In sandwich panels, the mass of the FRP skins combined with the damping effect of the foam core can provide good Sound Transmission Class (STC) ratings, making them effective for partitions in noisy industrial or agricultural settings.
For true acoustic performance, dedicated materials or composite assemblies are recommended.
