An acoustic transmission is retransmitted by telephone to a network operations center over one path. The network operations center receives acoustic transmissions containing inaudible marks from other sources over secondary paths. The retransmitted acoustic transmission and secondary transmissions are processed and compared to determine a best match between the retransmitted acoustic transmission and one of the secondary transmissions. An acoustic mark in the best match secondary transmission is decoded and associated with the retransmitted acoustic transmission. This association in combination with decision rules stored at the operations center may be used to trigger a variety of transactions with the user.