An implantable transducer converts an electrical stimulation signal into a corresponding mechanical stimulation signal. The transducer has an elongated shape with a transducer end face having a transducer drive surface adapted to produce the mechanical stimulation signal, and a transducer adhesive feature adapted to intra-operatively receive adhesive material. A separate coupling cap has a coupling end face with a coupling adhesive feature adapted to engage the transducer adhesive feature with the adhesive material and a coupling drive surface adapted for distortion-free coupling of the mechanical stimulation signal from the transducer drive surface to the coupling cap. A signal delivery surface of the coupling cap delivers the mechanical stimulation signal to an adjacent cochlear surface for sensation as sound.
