A mobile device or system comprises a housing, a voice sensor that is configured to detect sound, a speaker, and a processing circuit configured to operate in both a first mode and a second mode. The processing circuit receives instructions from a user by detecting the user touching the device or an accessory of the device when in the first mode and receives instructions from the voice of the user through the voice sensor when in the second mode. When a predetermined requirement is met, the processing circuit is configured to switch from a first mode to a second mode without receiving specific instructions from the user to switch the mode at the time of switching.