An audio system, an audio apparatus, and a method for performing audio signal output processing are provided that prevent the occurrence of sound interruption of high-priority voice signal output, such as voice guidance for navigation. The audio system includes the audio apparatus communicatively connected to an electronic device for producing an audio signal and to an electronic device for producing a high-priority voice signal (voice guidance signal). When the voice guidance signal is received with the audio signal being received, the audio apparatus starts to perform a mixing operation of the voice guidance signal. If a request for switching a sample rate of the audio signal is made during the mixing operation, the audio apparatus suspends a sample-rate switching operation until the mixing operation is completed.