Successful replacement of the sound conducting mechanism of the ear has been hampered by infection, perforation, prosthesis instability and extrusion. In this animal study on thirty rats a silicone prosthesis was inserted between two layers of fascia as a total replacement of the tympanic membrane and ossicular chain. After four months the graft was found to be intact without evidence of infection or extrusion in all but one of the 30 rats. These results justify a trial of a similar silicone prosthesis in humans.