Methods, systems, and computer programs for transferring a call described. In some aspects, during a voice call, a mobile device detects proximity of an audio appliance. The mobile device determines that the audio appliance is permitted to carry an audio portion of the voice call. The mobile device establishes a bi-directional communication link operable to transfer audio data between the mobile device and the audio appliance. In some instances, the audio data for the voice call is routed between the mobile device and the audio appliance by the bi-directional communication link.