An apparatus and method are disclosed, which separates ambient noise from a voice signal in a Bluetooth headset with dual microphones, switches the connection path between the dual microphones and automatically controls output audio gain, based on the ambient noise. The method for outputting the voice signal includes receiving/comparing the first and second input signals from the first and second microphones, extracting the voice signal of substantially identical intensity from the first and second input signals, and transmitting the voice signal from the portable terminal communicating with the Bluetooth headset.