Coupon management system, terminal device and program

The purpose of the present invention is to allow a terminal device to be able to recognize a usable coupon by way of sound. A coupon management server (10) associates together, and stores beforehand, acoustic sound information representing a predetermined sound, and coupon information. The coupon management server (10) acquires an acoustic signal indicating a sound that has been emitted by a terminal device (20) of a user via a store terminal (30) (S1 to S7). The coupon management server (10) extracts, from the acoustic signal, a terminal ID and time information which have been superimposed by way of an acoustic watermark upon the acquired acoustic signal (S8). The coupon management server (10), in a case of assessing that the acquired acoustic signal matches the acoustic signal information and succeeding in time authentication by way of the time indicated by the time information (S9 to S13), performs processing for providing, to the user indicated by the terminal ID, a coupon service corresponding to the coupon indicated by coupon information stored in association with the acoustic signal information (S14 to S16).