Broadcast monitoring is the process of tracking and observing activities on broadcasting channels in compliance with intellectual property rights and other illegal activities not conforming to broadcasting laws using the computer or human system. The problem here has a unique challenge from the pattern recognition point of view because a very high recognition rate is needed under non- ideal conditions. There is also a problem in comparing a small audio sequence with a large audio stream (the broadcast) searching for matches. Broadcast monitoring could be active or passive. In this paper we did a review of the various application and techniques useful to broadcast monitoring systems.