The manufacture of housing parts of a hearing apparatus and in particular a hearing device is to be simplified. To this end, provision is made to also efficiently use a so-called tumbling process for the surface treatment of housing. On account of this, a closure element is proposed for closing openings of housing parts for a hearing apparatus of this type during a tumbling process. The closure element has a disk-like center part, a first column section, which protrudes from the one side of the disk-like center part and has a first swelling on its free end, and a second column section, which protrudes from the other side of the disk-like center part and has a second swelling on its free end. A closure element of this type allows openings of housing parts, which are attached to the column sections, to be closed and protected for a tumbling process.