The global urbanization process has led to a rapid transformation of various urban and suburban habitats with profound consequences for biodiversity (e.g. McKinney 2006; Seto et al. 2012). Improving the conditions for biodiversity in cities has been suggested to contribute to quality of life for city dwellers (e.g. Tzoulas et al. 2007; Standish et al. 2012). For instance, human well-being in cities has been attributed to, among other factors, access to green space with variety in the form of species-rich habitats (e.g. Fuller et al. 2007; Dallimer et al. 2012). One important aspect of the presence of various organisms in urban areas is the opportunity for people to experience plants and animals for recreational purposes. This can be viewed as part of the ecosystem services in cities, i.e. the various benefits that humans receive from ecosystems including urban ones (MEA 2005; Clark et al. 2014). For many urban inhabitants, the everyday experience of biodiversity is gained by visiting a nearby green space in the city.However, there are still a number of less well-known links between people and biodiversity in urban green space. A focal question is how green space is perceived. We focus here on (1) the possible Bmismatch^ between variation in urban biodiversity and how it is perceived (e.g. Dallimer et al. 2012); (2) the importance of environment-related attitudes of different individuals for perception of green space (e.g. Lin et al. 2014); (3) how the natural sounds in urban green space are perceived in relation to biodiversity and environmentrelated attitudes (e.g. Viollon et al. 2002; Irvine et al. 2009). These approaches were employed because our previous studies have shown that environment-related attitudes and natural sounds influence perception (Knez and Thorsson 2006, 2008; Hedblom et al. 2014). Here we investigate the effects of, and interactions between, these factors regarding perception of urban green space. Below, we describe the concerns that are related to the three approaches. First, the relationship between actual and perceived biodiversity may not be so straightforward as might be expected (e.g. Fuller et al. 2007). Several studies have recently focused on this problem (Dallimer et al. 2012; Shwartz et al. 2014; Pett et al. 2016). For instance, in a study in England, it was shown that the well-being of visitors to green space was positively related to the perceived species richness of plants, birds and butterflies. But no consistent pattern was found between actual, measured species richness and the well-being of participants in the study (Dallimer et al. 2012). In other studies, the vegetation has been in focus because it is usually a major part of the perceived urban biodiversity. When flower diversity was experimentally increased in small public gardens in Paris, the visitors did not perceive any change in diversity before and after the manipulation although the participants expressed a preference for species richness (Shwartz et al. 2014).