A mobile communication terminal includes a receiver converting an audio signal outputted from the mobile communication terminal into an audible sound; a coupler dividing the audio signal outputted from the receiver into first and second audio signals which are different in phase from each other; an audio signal amplifier amplifying the second audio signal outputted from the coupler according to a predetermined amplification gain; a receiver port to which the receiver is detachably connected and which includes a first output port transmitting the first audio signal outputted from the coupler to the receiver and a second output port transmitting the second audio signal amplified by the audio signal amplifier to the receiver; and a controller controlling the mobile communication terminal and the amplification gain of the audio signal amplifier.