A motor vehicle includes an audio system and a control system configured to mute the audio system output automatically in response to input signals indicating an incoming call to any of two or more recognized cell phones or pagers. A digital input implementation employs a wire or cable from the cell phone directly to the control system. The cable carries a signal that is asserted whenever an incoming call is detected. An audio input implementation uses a set of audio detectors throughout the vehicle. The control system is “trained” to listen for a cell phone ring that matches any of a list of previously learned cell phone rings. The control system may support infrared and radio frequency implementations as well. In another embodiment, the control system detects the incoming call through the motor vehicle's external antenna in parallel with the detection of the incoming call by the cell phone.