In modern stressful society, it is desired to establish a psychosomatic stress relaxation method. So we focused on the 1/f fluctuation, which is said to give a comfortable feeling and healing effect on people. In the previous study, we show that the sympathetic nerve activity, LF/HF, is reduced significantly by listening to 1/f fluctuation music. However, we obtain that there is the correlation between the trend of LF/HF and the preference about "likes and dislikes” of music listening. This suggests that it cannot show the effect of the 1/f fluctuation without removing an element of the preference such as "likes and dislikes". So, in order to solve this problem, we propose to use the ultrasonic waves modulated by 1/f fluctuation. As a result, we show that the LF/HF decreases significantly when the subjects received the ultrasonic waves modulated by 1/f fluctuation, namely parasympathetic activity has shown to be dominant. It shows to be effective to alleviate the psychosomatic stress by using 1/f fluctuation.
