Validation of the Tranquillity Rating Prediction Tool (TRAPT): comparative studies in UK and Hong Kong

Abstract The Tranquillity Rating Prediction Tool (TRAPT) has been used to make predictions of the quality of tranquility in outdoor urban areas using two significant factors i.e. the average level of anthropogenic noise and the percentage of natural features in view. The method has a number of applications including producing tranquillity contours that can inform decisions regarding the impact of new anthropogenic noise sources or developments causing visual intrusion. The method was intended for use in mainly outdoor areas and yet was developed using responses from UK volunteers to video clips indoors. Because the volunteers for this study were all UK residents it was important to calibrate responses for other ethnic groups who may respond differently depending on cultural background. To address these issues further studies were performed in Hong Kong using the same video recording played back under the same conditions as the study in the UK. The HK study involved recruiting three groups i.e. residents from Hong Kong, Mainland China and a diverse group from 16 different nations. There was good agreement between all these groups with average tranquillity ratings for the different locations differing by less than one scale point in most cases.