The present invention concerns an actuator for an implantable hearing aid for implantation into the human middle ear. The actuator comprises a substantially elongate piezoelectric component (34, 36) having first and second operating end faces (41, 43), said end faces extending substantially at right angles to the longitudinal axis of the piezoelectric component. Also there is provided a frame component comprising at least one flextensional amplifier element (32), the flextensional amplifier element being integral with and connecting first and second frame end portions (42, 44), the first and second frame end portions also extending substantially at right angles to longitudinal axis of the piezoelectric component when fitted thereto, whereby the first and second end portions are in contact with the piezoelectric component end faces.