A cochlear implant system, comprising: a cochlear implant comprising: an electrode array (112, 114) adapted to be implanted within a cochlea, an internal processor in communication with the electrode array, and an antenna electrically coupled to the internal processor; and an external headpiece (102, 400, 500, 500a, 700, 800, 900) configured as a stand alone, head-mounted unit which provides external functionality for operation of the cochlear implant system, wherein at least one of the cochlear implant and the external headpiece includes a magnet (123, 476), the other of the cochlear implant and the external headpiece includes a magnet (123, 476) or magnetic material, and the magnetic attraction associated therewith allows the external headpiece to be removably positioned over the antenna such that a portion of skin is sandwiched between the antenna and the external headpiece, characterised in that: the external head piece is a modular external headpiece comprising: a core (405, 405a) containing a sound processor for processing sound and providing a corresponding signal to the antenna, the core comprising a lower surface that faces the cochlear implant and an upper surface that faces in a direction opposite the lower surface, and a modular component (410, 510, 710, 810, 905) configured to releasably engage the core and supply electrical power to the core; the core and the modular component being respectively configured such that, when the modular component engages the core to form the modular external headpiece, the modular component is configured to at least partially enclose the perimeter of the core and to leave at least a portion of the upper surface and the lower surface of the core exposed. a cochlear implant comprising: an electrode array (112, 114) adapted to be implanted within a cochlea, an internal processor in communication with the electrode array, and an antenna electrically coupled to the internal processor; and an external headpiece (102, 400, 500, 500a, 700, 800, 900) configured as a stand alone, head-mounted unit which provides external functionality for operation of the cochlear implant system, wherein at least one of the cochlear implant and the external headpiece includes a magnet (123, 476), the other of the cochlear implant and the external headpiece includes a magnet (123, 476) or magnetic material, and the magnetic attraction associated therewith allows the external headpiece to be removably positioned over the antenna such that a portion of skin is sandwiched between the antenna and the external headpiece, an electrode array (112, 114) adapted to be implanted within a cochlea, an internal processor in communication with the electrode array, and an antenna electrically coupled to the internal processor; and an external headpiece (102, 400, 500, 500a, 700, 800, 900) configured as a stand alone, head-mounted unit which provides external functionality for operation of the cochlear implant system, wherein at least one of the cochlear implant and the external headpiece includes a magnet (123, 476), the other of the cochlear implant and the external headpiece includes a magnet (123, 476) or magnetic material, and the magnetic attraction associated therewith allows the external headpiece to be removably positioned over the antenna such that a portion of skin is sandwiched between the antenna and the external headpiece, a core (405, 405a) containing a sound processor for processing sound and providing a corresponding signal to the antenna, the core comprising a lower surface that faces the cochlear implant and an upper surface that faces in a direction opposite the lower surface, and a modular component (410, 510, 710, 810, 905) configured to releasably engage the core and supply electrical power to the core; the core and the modular component being respectively configured such that, when the modular component engages the core to form the modular external headpiece, the modular component is configured to at least partially enclose the perimeter of the core and to leave at least a portion of the upper surface and the lower surface of the core exposed.