Abstract: A communication system includes an input (202) for requesting and receiving a first message information format and for requesting and receiving a second message information format, and controller (210) for detecting a measure of communication activity and for comparing the measure of communication activity to a threshold that is adaptable by the controller (210) as a function of the communication activity. The communication system accepts the first message information format when the measure of communication activity is below the threshold (604, 610, 606, and 608), and accepts the second message information format when the measure of communication activity is above the threshold (604, 610, 612, 614, and 616).

Abstract: An alerting device, such as a radio pager, which produces an audible alerting signal includes a signal level control which causes the alerting signal to be initially produced at a low audio level, with the signal increasing or escalating to a higher audio level. The signal level can increase continuously in a smooth rise, or can increase in steps. The level control can include an attenuator which initially reduces the signal level, to which a control signal is applied to reduce the attenuation and increase the alerting signal. The attenuator can be coupled to an audio amplifier so that the overall gain of the signal applied to the transducer producing the audible signal is increased from an initial low signal level as the signal continues.