Surface Deformation: Imported Solids

Hi All
I have a simple shape that I would like to apply a procedural/parametric random deformation for the purpose of nulling acoustic reflection within a speaker enclosure.

Basic object

Im wanting the external surface to have very subtle divets applied ie random bump noise with a surface scale of eg 20mm and eg min/max of 5mm but not just an imaging displacement/bump but rather a true surface deform.

Just a point in the right direction would be brilliant!