A portable device for detecting a radio frequency transmission of electromagnetic radiation includes a housing; a controller situated within the housing; memory communicatively connected to the controller; an antenna connected to the controller and configured to receive the radio frequency transmission; and an audio-generating component connected to the controller. The radio frequency transmission of the electromagnetic radiation is harmful to an electrical device and is from a transient electromagnetic device (TED) threat source. The controller is operative for sensing magnitude, duration, and/or repetition of the radio frequency transmission; identifying a class of the radio frequency transmission based on one of the magnitude, duration, and repetition associated with the radio frequency transmission; and causing the audio-generating component to output tones to provide aural discrimination of an identified class of the radio frequency transmission received by the portable device. The identified class is a transient electromagnetic pulse signal from the TED source.