An example method includes receiving, by a computational assistant executing at one or more processors of a mobile computing device and via a wireless link between the mobile computing device and an external device, a representation of audio data generated by a microphone of the external device, the audio data representing a spoken utterance detected by the external device; determining, by the computational assistant and based on the audio data, a response to the spoken utterance; and sending, by the mobile computing device, to the external device, and via the wireless link between the mobile computing device and the external device, a command to output, for playback by one or more speakers connected to the external device via a hardwired analog removable connector of the external device or a wireless link between the external device and the one or more speakers, audio data representing the response to the spoken utterance.