A cellular telephone operable to interact with an audio transmission, the apparatus comprising: a memory operable to store control data for causing the telecommunications apparatus to respond to the audio transmission; a receiver operable to receive an acoustic signal of the audio transmission and for converting the received acoustic signal into a corresponding electrical signal; a data processor, coupled to said acoustic signal receiver, and operable to process said electrical signal to recover data encoded within the audio of said audio transmission and to provide the recovered data to the telecommunications apparatus; and a responder operable to respond to the data recovered from the audio transmission in accordance with the stored control data after a delay defined by stored timing data to synchronize the response with the audio transmission.