Abstract: A mobile communication device (100) determines a background noise level at a microphone (104). If, after determining the noise floor, the input signal exceeds a threshold, the mobile communication device transmits the input signal. The threshold is established such that if it is exceeded, it is likely that voice energy is being received at the microphone, and the threshold, in a first embodiment, is increased as the background noise level increases. In a second embodiment the threshold is determined as the difference between the input signal and the background noise level. As background noise increases, the threshold actually decreases.

Abstract: A mobile communication device containing voice recognition capability is first enabled to perform voice recognition (102). The user then speaks the name of the party the user wishes to call (104), the name corresponding to a record the user has programmed into a memory of the mobile communication device. The mobile communication device then uses the output (106) of the voice recognition process to search the memory for a corresponding record (108). The record contains at least two calling numbers, each associated with a different mode of communication, such as dispatch and telephone communication. For a brief period of time after locating the record, the mobile communication device waits (118) for the user to initiate a call in the first communication mode (120) by, for example, pressing a dispatch call button (124). If, after a preselected duration of time has passed and no input is received from the user, the mobile communication device defaults to a second communication mode and makes a call (122).