The inspiration for this acoustic absorption panel is based on the work of juliendorra, found at: https://github.com/juliendorra/3D-printable-sound-absorbers

I have changed the original designs by removing the perforated face panel, shrinking it by 50% (because more/smaller holes are described as better), and assembling multiple face panels/ segmented backing modules/ and a coplanar coiled air chamber into a monolithic, printable assembly of 200mm x 200mm.

The goal of this object is to absorb wide-spectrum sound (noise) for a quieter environment, and to improve the acoustics of a room by removing sound energy that falls onto the face of the panel. Important criteria are low cost, and low weight, which drives the technical shapes and minimal filament consumption of this print. The side with the perforated surface points toward the room.

If you are looking for a diffuser instead of an absorber (and they work well together), I have made a Quadratic Residue Diffuser here: https://www.thingiverse.com/thing:3894262

One assembly requires just under 50m of filament to print, using a 0.4mm nozzle. This panel requires the bending of some default settings in my slicer (slic3r PE), and the side walls are delicate before attaching to a firm surface.

Furthermore, this was one of the first things I made in CAD (and a project that helped coax me into buying a printer), and I'm interested in the subject matter, so there may be a couple of improvements I could make if community interest is there.

I don't have the equipment to perform respectable tests on its effectiveness, but in my unqualified opinion, it works far better than expected.

Update December 22, 2020: Remodeled the components of the 200x200mm panel for thicker walls for those who don't have the ability to print a 1-line-wide wall. It is much more rigid, but also takes even longer than forever to print, and is no longer filament efficient. The recommended print for making a sizeable composite panel is still the original.