A system includes one or more sensors to detect one or more properties for a current user wearing a head-mountable display (HMD), control circuitry to select a user profile from a plurality of stored user profiles in dependence upon one or more of the detected properties, where each stored user profile is associated with a respective user and includes data indicative of one or more reference properties for the respective user, where the selected user profile includes data indicative of at least one reference property that is substantially the same as at least one of the one or more of the detected properties, and processing circuitry to generate at least one of audio and video content for output by the HMD in dependence upon the selected user profile and in response to the selection of the user profile.