Method of and system for identification and verification of broadcasted television and radio program segments

A method of and system for identification and verification of TV and/or radio broadcasted program segments involves use of subaudible codes which are mixed with the conventional audio in the program segments. Individual program segments have at the beginning thereof a preamble code (such as a predetermined number of cycles of 40 Hz.), a program segment identification code (which may consist of a series of alphanumeric characters) and a postamble code (such as a given number of cycles of 40 Hz.). A plurality of radio/television broadcast stations (A-F) are monitored, the codes recovered and data sets defined, stored and later sent to a central location (31) for reconciliation and/or compilation. In the case of television stations, the video content of at least commercial message segments may be monitored to determine video signal continuity by monitoring the presence and/or absence of video signals.