A mobile communication device includes: a first sound transceiver including a first lower electrode, a first upper electrode, and a first vibration plate between the first lower electrode and the first upper electrode; a second sound transceiver including a second lower electrode, a second upper electrode, and a second vibration plate between the second lower electrode and the second upper electrode; a position sensor configured to perform a detection of a relative positional relationship between the first and second sound transceivers; and a controller configured to apply a sound signal to one of the first and second sound transceivers and detect a sound signal from the other one thereof, based on the detection result provided from the position sensor.