Abstract: A method and system for detecting the presence, and the location of, a concealed listening device. In the method, the acoustic signal from the actual acoustic source and electromagnetic signals in the radio frequency band (containing the electromagnetically-transmitted version of the acoustic signal on an unknown frequency) are obtained and an average cross correlation of the auto correlation of each of these two signal types is derived for determining whether a concealed listening device is even present and, if so, the frequency of the electromagnetically-transmitted version. The method then utilizes timed pulse responses of a plurality of acoustic transducers, as well as a distinguishing function, to determine the location of the concealed listening device. In the system, a controller controls the operation of a radio receiver, a microphone and an arrangement of acoustic transducers in accordance with the method described above.