Abstract: Individual audio tracks (20-24) for interactive reproduction at a remote toy (104) are each encoded with a sub-audible tone (12-18) or code that uniquely identifies the track with audible output and/or functional operation of the toy (104). Detection of the sub-audible tone at the interactive toy opens the audio path and permits related motor control in the toy, whereas absence of a relevant sub-audible tone disables at least the audio and, preferably, both the toy's speaker (122) and at least one controllable motor (130, 132). The sub-audible tone (12-18) or code is inserted for the duration of activity only and may come into and out of existence as a specific character track (amongst the plurality of individual audio tracks) moves between active and inactive phases.