Abstract: A method and apparatus for the identification and verification of audio transmission segments, such as may be broadcast by a radio station, consists of the generation of a data stream corresponding in duration to the length of the program segment and including both cumulative time data and segment identification data. The data stream is combined with the program segment to which it relates in a manner in which the data is inaudible on conventional reception apparatus and which does not significantly degrade the audio quality of the program segment. A reception facility is provided to extract the data stream from the recorded audio and compare the data therein with reference data for the transmission, including intended length and time of the segment. By such a comparison verification of the broadcast can be accomplished.