Psychological Evaluation of Environmental Noise in Field Using the Method of Continuous Judgment by Category

Oneof the aims of noise research is to predict the annoyance of sound environment that consists of sounds from various sources. Many social surveys have been conducted in order to find the relation between physical indices of noise and the psychological responses. Social surveys have a merit that the responses in daily life can be obtained. But in many cases correlation between physical indices of noise and the psychological responses is not so high. This may be due to the fact that various physical, physiological and psychological factors are involved in the evaluation of annoyance. Besides, the structure of noise situation in daily lifeis much more complicated than that in laboratory condition(e. g. Berglund, 1991). 0n the other hand, high correlation can be found between physical indices of noise and the psychological responses in laboratory conditions where physical properties of sounds can be precisely controlled. It is possible to find the physical index which shows good correlation with psychological responses in laboratory experiments. However, the situation in laboratory is very simple and different from in daily lifesituations. The findings in laboratory experiments cannot always be applied to daily lifesituations directly. New approach has been developed called“simulated environment eχperiment" in order to obtain the responses to noise with high validity and reliabilityin laboratory situations. A typical furnished living room was constructed in the laboratory. The loudspeakers behind walls and /or ceiling can reproduce sounds with high fidelity. Subjectscan