Abstract: An audio device is provided that is arranged for communication of data and signalling with a controller, signalling from the device to the controller being made in discrete time slots, the device comprising: a plurality of nodes, each assigned a priority value and each having one or more unsolicited response sources capable of generating an unsolicited response for transmission to the controller, wherein unsolicited responses generated from a particular node are assigned the priority value of that node; and unsolicited response management means operable to hold unsolicited responses generated by the plurality of nodes that are awaiting transmission to the controller, wherein when two or more unsolicited responses are awaiting transmission to the controller in the unsolicited response management means, the device is arranged to transmit the unsolicited response with the highest assigned priority value first, in the next free time slot.