A portable electronic device having an audio jack is provided. The device comprises: a processor; a jack for receiving a plug of an audio accessory; electrical connectors provided in the jack for enabling communication between the audio accessory and the processor and for contacting corresponding electrical connectors of the plug; and a switching circuit in communication with the processor and two of the electrical connectors. The switching circuit routes audio signals between the corresponding electrical connectors and the processor; after insertion of the plug into the jack, conducts a test on the electrical connectors to determine if a first one of the corresponding electrical connectors is electrically grounded. A method for routing the signals is also provided.