A mobile terminal device includes: a telephone communication speaker and a control module. The telephone communication speaker includes: a first speaker which releases sound waves corresponding to sounds to be output and vibration waves generated by vibrations of one surface of a housing according to vibrations corresponding to the sounds to be output, thereby to transfer the sounds to a user; and a second speaker which releases sound waves corresponding to sounds to be output. In case of execution of a function to output sounds from the telephone communication speaker, when a predetermined trigger action is not made, the control module executes first control in which the first speaker outputs sounds but the second speaker does not output sounds, and when the trigger action is made, the control module executes second control in which at least the second speaker outputs sounds.