I ordered a life-size man head several days ago so that I can build my gasmask on it, and properly place the copper ears. While waiting for that to arrive I finished the two tusks. Functionally they are bad air transmutators, which convert foul gases to something breathable. In other words, the working end of the gas mask. They just happen to bear an uncanny resemblance to elephantine tusks when juxtaposed with the pressure hose and sound amplifiers.
The picture shows my construction of various plastic and metal parts on the left, which I molded in silicone rubber, then cast in cold cast bronze (a mixture of urethane resin and atomized bronze and brass). The finished transmutator is on the right.