A first group auditory data stream, from a transmitting subscriber device of a first group of subscriber devices or from a dispatch console and intended for the first group of subscriber devices, is received at a conference server. A second group auditory data stream from a transmitting subscriber device of a second group of subscriber devices is similarly received. The conference server determines a relative priority level of one of (i) the first group of subscriber devices relative to the second group of subscriber devices and (ii) the first group auditory data stream relative to the second group auditory data stream, and sets different relative signal gains of the first group auditory data stream and the second group auditory data stream as a function of the determined relative priority level. The two auditory data streams are then summed and forwarded towards the second group of subscriber devices.