A fenestration piercing the otic capsule bone of the cochlea receives a therapeutic appliance, such as a microactuator, plug, micropump for drug or therapeutic agent delivery, electrode, and the like. Several different ways of achieving a ‘water tight’ seal between the otic capsule bone and the therapeutic appliance are provided. The therapeutic appliance may be implanted with or without a sheath or sleeve lining the wall of the fenestration formed using specialized surgical burrs. The burrs permit safely fenestrating the otic capsule bone adjacent to the scala tympani of the cochlea without damaging the basilar membrane or organ of corti. This approach may also be adopted for safely fenestrating other areas of the inner ear such as the scala vestibuli, bony labyrinth of semicircular canals, or walls of the vestibule, or the oval or round windows thereof.