An apparatus and method for providing an emergency alert service in a portable terminal and for generating an alarm for the emergency alert service are provided. The method includes detecting, by a controller, an SOS execution signal while the portable terminal is being operated in a certain mode, identifying, by the controller, a current operating mode of the portable terminal in response to the SOS execution signal, outputting a control signal according to the identified operating mode to a source audio signal processor, and outputting, by the source audio signal processor, a source audio signal according to an input port receiving the control signal.