An electrode unit (11) is provided for use in cranial electrostimulation in which an electric current transferring electrode (15, 31) operatively transfers electrical energy to the region of an ear of a patient. The electrode unit has an electrode carried on the outer periphery of an audio earphone (12) of the type suitable for engagement in the entrance to, or within, the auditory canal of an ear of a patient. The electrode has an electrical contact area for operatively transferring electrical energy between the electrode and the skin of a patient fitted with the electrode unit. The electrode may have a contact surface layer exposed for direct contact with the skin of a patient, in use, or it may have an electrically conductive cover (16) for the electrode itself. Typically, the electrode unit forms one of a pair thereof in which instance the audio earphones are a pair of stereo earphones of substantially conventional type.
