The Psychological Effect of Visual and Auditory Stimuli on the Road Traffic Noise Perception

Several studies on audio-visual interactions have shown that the visual stimulus can influence loudness of traffic noise. And it was shown that the auditory stimulus such as music in the street can reduce the road traffic noise perception. On the base of these results, a series of experimental studies were carried out and reviewed the psychological effect of visual and auditory stimuli on the perception of road traffic noise.The first experiment was designed to assess the visual effect of twelve roadsides with different landscapes on the road traffic noise perception. As a result, approx. 3 to 5 dB(A) of psychological reduction was seen in places where natural landscape was preferred, compared to the others, although the noise levels were similar. The second experiment was designed to evaluate the effect of visual screening from adjacent roads on road traffic noise perception by means of ME method in a laboratory. As the result, the effect of psychological reduction was observed at 65 dB(A) or lower. Especially, the barrier which screening optically from adjacent roads led to 5 to 10% of loudness reduction effect, compared to non-screening cases.Finally, the third experiment was designed to evaluate the effect of visual and auditory stimuli with ME method and 7-point SD rating scale in a laboratory. And it was found that up to 10% of loudness reduction and about 2 dB(A) of noise perceptional reduction were seen at 65 dB(A) or lower.