A method for providing an emergency alert service in a portable terminal, the method comprising: detecting, by a controller, an SOS execution signal generated by an SOS input unit of the portable terminal in response to a user's request; identifying, by the controller, a current operating mode of the portable terminal in response to the SOS execution signal; transmitting, by the controller, a control signal according to the identified operating mode to a source audio signal processor; and generating, by the source audio signal processor, a source audio signal according to the received control signal for outputting the source audio signal via a sound output unit of the portable terminal, wherein the step of detecting of the SOS execution signal comprises activating an electrical power supply line of the source audio signal processor for outputting the source audio signal if the source audio signal processor receives electrical power via the electrical power supply line, wherein the generating of the source audio signal comprises: receiving the control signal from the controller; and retrieving a source audio signal corresponding to the received control signal for outputting the source audio signal via the output unit, wherein, when said current operating mode is identified as a call mode, the step of generating (417, 525) the source audio signal comprises controlling output of the source audio signal by delaying the output of the source audio signal for a particular period of time. detecting, by a controller, an SOS execution signal generated by an SOS input unit of the portable terminal in response to a user's request; identifying, by the controller, a current operating mode of the portable terminal in response to the SOS execution signal; transmitting, by the controller, a control signal according to the identified operating mode to a source audio signal processor; and generating, by the source audio signal processor, a source audio signal according to the received control signal for outputting the source audio signal via a sound output unit of the portable terminal, wherein the step of detecting of the SOS execution signal comprises activating an electrical power supply line of the source audio signal processor for outputting the source audio signal if the source audio signal processor receives electrical power via the electrical power supply line, wherein the generating of the source audio signal comprises: receiving the control signal from the controller; and retrieving a source audio signal corresponding to the received control signal for outputting the source audio signal via the output unit, wherein, when said current operating mode is identified as a call mode, the step of generating (417, 525) the source audio signal comprises controlling output of the source audio signal by delaying the output of the source audio signal for a particular period of time. receiving the control signal from the controller; and retrieving a source audio signal corresponding to the received control signal for outputting the source audio signal via the output unit, wherein, when said current operating mode is identified as a call mode, the step of generating (417, 525) the source audio signal comprises controlling output of the source audio signal by delaying the output of the source audio signal for a particular period of time.