To allow a user to provide a voice instruction to either a portable device or a computing device embedded within a vehicle, both the portable device and the embedded computing device receive the voice instruction such as, “Direct me to Kansas City.” Moreover, both the portable device and the embedded computing device may determine the likelihoods that the portable device and the computing device, respectively, can carry out the voice instruction. The portable device and the computing device may then communicate with each other to compare the determined likelihoods. Based on the comparison, either the portable device or the computing device may respond to the voice instruction by, for example, playing a requested song, turning on the radio in the vehicle, providing navigation directions from the current location to a destination, etc.