This study discusses the combined effect of auditory and visual factors on comprehensive comfortableness. We used the concept of "harmonious sensation" to explain this effect. To clarify the function of this sensation, we conducted two psychological experiments. The result shows that harmonious sensation, visual and auditory comfortableness has an equal influence on comprehensive comfortableness. The effect of harmonious sensation was varied according to the degree of visual and auditory comfortableness; This effect increased as the difference in the degree of comfortableness between visual and auditory factors becomes wide.