A new tranquility rating tool and the role of audio and visual interactions.

Restorative environments which enable individuals to recover the sense of well‐being are becoming increasingly important. These environments are characterized by an enhanced level of tranquility. Therefore, obtaining the optimum balance between the landscape and soundscape characteristics and measuring the resultant tranquility of these spaces are essential for their design and maintenance. In order to understand the key factors which affect the tranquillity construct, a large volume of audio and visual data has been collected across a representative range of landscapes in the UK. These data have been analyzed objectively by studying the temporal and spectral characteristics of the recorded sounds and the proportion of the natural and contextual features present in the video clips. The tranquility rating of these landscapes has been obtained from subjective experiments on 44 subjects to whom uni‐ and bimodal stimuli have been presented in a separate experiment. The results of these experiments make possible to objectively measure the key components of the tranquillity construct and determine their relative importance in the design of a restorative space. On this basis new relations between the tranquility rating, sound pressure level, loudness characteristics, and the visual quality of the scene have been derived.