An apparatus and method for indicating sources of high error conditions, including out-of-range and interference conditions, to a user of a digital voice communication system. When the vocoder (206) of a communication unit (200, 450) silences due to high error conditions, a source of the high error conditions (e.g., out-of-range or interference) is determined based on the signal strength, and a source indicator (218, 220) is generated to inform the user of the source of the high error conditions...