An experiment on auditory and non-auditory disturbances caused by railway and road traffic noises in outdoor conditions

In a laboratory experiment, disturbance caused by two types of noise (railway and road traffic noises) at three noise levels (55, 65 and 75 dB L Aeq ) in two kinds of stimulation conditions (listening and calculation) was investigated. Thirty Japanese and thirty Chinese subjects performed a listening or calculation task while each noise was presented for 6 min. The subjects assessed the disturbance of their activities using 5-point verbal scales constructed by ICBEN method. A railway bonus, mainly caused by noise masking, was found in the listening task but not in the calculation task. There was a significant difference between the effects of two noises on listening performance when noise level was 75 dB, but no difference was found between railway and road traffic noises on task performance. The results suggest that the disturbance evaluation is determined by several factors and that the interaction among the factors increases with the increase of noise level. Evaluation disturbance is not related to task performance in certain cases.