Abstract: Deafness is often caused by damage to the ossicular chain, which at present is partly or fully replaces by surgical implantation of a corresponding titanium prosthesis. Known versions of this type of middle ear implant consist of a flat coupling body (8) designed to rest against the ear drum, an oblong shank (3) connected to the body for bridging the tympanic cavity and a base (4,11) which is joined to the shank (3) and rests against the base of the implant in the tympanic cavity. Because the depth oft he tympanic cavity varies from patient to patient and measurements become known only during surgery, the length of the implant has to be adjusted very quickly.