A radio receiver includes a voice-only detection mechanism that detects when the current radio station is transmitting mostly voice, and that changes the function of the receiver depending on whether or not the current radio station is transmitting mostly voice. In a first embodiment, the radio receiver mutes its audio output when the voice-only detection mechanism detects a voice broadcast, or mutes its audio output when the voice-only detection mechanism detects a music broadcast. In a second embodiment, the radio receiver changes to a different radio station when a voice-only signal is detected, or when a music signal is detected. The second embodiment preferably includes a spectrum analyzer that can store a frequency spectrum "signature" of a radio signal, and a second tuner that scans the available radio stations for a signal that matches the stored signature.