inform the various schemata used to characterise differing landscape types. This interpretation is supported by the auditory reaction times, which are 50 to 60ms faster than that of the visual modality. It is also known that sound can alter visual perception and that under certain conditions areas of the brain involved in processing auditory information can be activated in response to visual stimuli. Research conducted by Pheasant et al. has shown that when individuals make tranquillity assessments based on a uni-modal auditory or visual sensory input, they characterise the environment by drawing upon a number of key landscape and soundscape characteristics. For example, when making assessments in response to visual-only stimuli the percentage of water, flora and geological features present within a scene, positively influence how tranquil a location is perceived to be. Likewise when responding to uni-modal auditory stimuli, the perceived loudness of biological sounds positively influences the perception of tranquillity, whilst the perceived loudness of mechanical sounds have a negative effect. However, when presented with bi-modal auditory-visual stimuli the individual soundscape and landscape components alone no longer influenced the perception of tranquillity. Rather configurational coherence was provided by the percentage of natural and contextual features present within the scene and the equivalent continuous sound pressure level (LAeq). Predicting tranquillity Researchers at the Bradford Centre for Sustainable Environments have developed a methodology by which the perceived tranquillity rating (TR) of an amenity area such as park, green or urban square can be measured, on a 0–10 scale. The method involves the assessment of average daytime noise levels Lday (usually traffic noise) and the measurement of the percentage of natural and contextual features NCF contained within the visual scene. The latter includes the percentage area in the visual scene occupied by natural features in the landscape such as vegetation, water and geological features, e.g. exposed rock outcrops, and contextual features. These contextual elements include listed buildings, religious and historic buildings, landmarks, monuments and elements of the landscape, such as traditional farm buildings, that directly contribute to the visual context of the natural environment. Lastly, the equation includes moderating factors (MF) that can influence the perception of tranquillity in either a positive, or a negative way: TR = 9.68 + 0.041 NCF − 0.146 Lday + MF. These moderating factors are not expected to be large and because they are relatively difficult to quantify they are the subject of ongoing research.