A speaker apparatus includes a speaker, a connection plug detachably and electrically connected to an earphone jack of the portable terminal, an amplifying block for amplifying an audio signal to output the amplified audio signal through the speaker, a RF modulation block for modulating the audio signal into an RF signal, and a switching block for selectively switching the audio signal to either the amplifying block or the RF modulation block. The speaker further includes an antenna for receiving a wireless aerial radio signal. The received radio signal is provided through the connection plug to the portable terminal in order for processing thereof.