Abstract
This paper describes the improvement of the active control of machinery noise to comfortable sound referred to insect's singing. In order to increase the resolution of comfortable functions, continuous acoustic psychological experiment is carried out. It is then confirmed that the results obtained by the experiment are correlated with the result obtained by the conventional experiment. Through the many experiment for a certain tester, it is confirmed that there is optimal Chirp period to maximize comfortableness. The active control experiment with the optimal Chirp period shows that the optimal Chirp period is effective.
