Abstract
In this research, an index of the relaxation degree for each user is obtained by the electroencephalogram information, and a system with the automatic tuning function of the sound is developed. We construct beforehand the index for measuring the relaxation degree using the electroencephalogram information. At first, the change of electroencephalogram power content ratio for θ, α, and β wave's frequency band are displayed in the three-dimensional state diagram, and we analyze the electroencephalogram feature. Based on the hypothesis about the relationship between the electroencephalogram and the relaxation, the relaxation tendency is grasped in the three-dimensional state diagram. Then, we construct an index which can be measured quantitatively that a subject is in the relaxation state. As a result of experiment for six subjects, we confirm an efficiency of the relaxation degree for the change of electroencephalogram of the subject. We have already developed the Interactive Chaotic Amusement System (ICAS) that generates the sound deciding the musical note, duration and volume by using network of chaotic elements that is able to control a synchronous and an asynchronous behavior. We aim to construct the system to tune the parameters of ICAS automatically from the generated sounds to the relaxation sound. We make six subjects use the proposed sound generation system and compare the result of relaxation effect estimated by this system with the questionnaire result after subjects listen to the generated sounds. As a result, it is confirmed that the results of subject's questionnaire and the index of the proposed method are correlated.
