Abstract
This thesis examined whether bird sounds are perceived and experienced as restorative following stress and cognitive fatigue, and reasons for such perceptions. Study 1 (N = 20) qualitatively explored restorative perceptions of bird sounds. These arose based on cognitive and affective appraisals of the sounds, and on relationships with nature. Restorative perceptions of bird sounds varied between species as a result of their acoustic, aesthetic, and associative properties. Study 2A (N = 174) quantitatively demonstrated that smoothness, intensity, complexity, pattern, and familiarity were significant predictors of restorative perceptions of bird sounds. Study 2B (N = 116) complemented these results by qualitatively examining associations with the sounds, which were summarised by four master themes: environment, animals, time and season, and environmental activities. Birds perceived as differently restorative in Study 2A were dissociable on the basis of different associations within these master themes. Study 3 (N = 102) experimentally examined the effects of associations on restorative perceptions of bird sounds. Bird sounds associated with positive scenarios were perceived as more restorative than those associated with negative scenarios. Scenarios describing the presence versus absence of threat, and associations with natural versus urban environments, were found to be particularly influential. Study 4 (N = 36) experimentally examined restorative outcomes in response to bird sounds. Listening to birdsong significantly reduced self-reported negative affect in comparison to traffic sounds, but no significant differences were found between sounds in terms of change in positive affect, arousal, or cognition. Qualitative data indicated that listening to the two types of sound generated different imagery of wider natural and urban environments. These four studies reveal the importance of bird sounds in perceptions and experiences of restoration, and the contributions of their acoustic, aesthetic and semantic properties to such perceptions – including associations with wider, multi-sensory environments.