Models of sound-absorbing panels those typically used in recording studios, listening rooms or used also as decorative panels.
The models are procedurally generated via geometry node group, so they are configurable in size and shape.

The .blend file comes with five panel types and a volumetric shader that well-simulates the typical spongy and soft look of foam panels.

WARNING: although the geometry node, generated models and the default material "SBAPPS Black Foam" work correctly with both Cycle and EEVEE, the other provided materials (volumetric) are intended exclusively for Cycle and do not work with EEVEE.