Effect of visual movement on loudness judgment of auditory stimulus

摘要

It is well known that there exists the interaction among multiple modalities (ex. vision and audition) in human perception, such as the ventriloquism effect. The interaction of audition and vision is caused by the various factors, and the relation among them is so much complicated. While some psychophysical researches focused on the simultaneity of the audio and the visual events exist, the investigation on the effects of the dynamic properties involved in both events seems rare. In our previous study, the effect of the simple movement involved in the visual stimulus on the perception of the audio stimulus was investigated via psychophysical experiments (Proc. of WESPAC IX 2006). The visual stimulus given to subjects along with audio stimulus was a bar indicated on a display, one side of which is flexibly expanding and contracting. Such a movement of the visual stimulus is associated, in general, with the level of sound, such as a level meter of audio player. However, the audio-visual stimuli with inconsistent correspondence were included at a certain rate. The rate is called “validity rate” of visual stimulus (with reference to the audio stimulus). A pair of such audio-visual stimuli were presented to subjects, and they compared the loudness of the audio stimuli. We reported that the control of the validity rate did not affect systematically strength of the interaction. Especially, the individual difference in the experimental results among the subjects was not so small as to find the systematical interaction between the audition and the vision due to the validity rate. In this manuscript, in order to clarify the cause of such results, another experiment was conducted controlling the amount of the inconsistency and the instruction on the answer policy. It was shown from the results of the experiment that the amount of the inconsistency influences the physical connection, and that the difference in the instruction produces the significantly large individual variation in the subjects' answer.