PROBLEM TO BE SOLVED: To improve inappropriate property of linkage with music for enhancing a music experience.SOLUTION: A stimulant information detection part 103 detects stimulant information of each of plural signal intensities out of signals taken out by a signal take-out part, by comparison of set plural thresholds and each signal intensity. For example, in the stimulant information detection part 103, N pieces (N is a natural number of 2 or higher number) of thresholds, the signal (digital signal) is compared sequentially, from a minimum threshold Vth1 to a maximum threshold VthN. For example, when the signal intensity Vs1 of the digital signal (sampling signal) at a certain time point is Vth2≤Vs1