The development of ICT infrastructures has facilitated the emergence of new paradigms for looking at society and the environment over the last few years. Participatory environmental sensing, i.e. directly involving citizens in environmental monitoring, is one example, which is hoped to encourage learning and enhance awareness of environmental issues. In this paper, an analysis of the behaviour of individuals involved in noise sensing is presented. Citizens have been involved in noise measuring activities through the WideNoise smartphone application. This application has been designed to record both objective (noise samples) and subjective (opinions, feelings) data. The application has been open to be used freely by anyone and has been widely employed worldwide. In addition, several test cases have been organised in European countries. Based on the information submitted by users, an analysis of emerging awareness and learning is performed. The data show that changes in the way the environment is perceived after repeated usage of the application do appear. Specifically, users learn how to recognise different noise levels they are exposed to. Additionally, the subjective data collected indicate an increased user involvement in time and a categorisation effect between pleasant and less pleasant environments.

Multi-touch user interfaces (MTUIs) can represent a valuable tool for enhancing human-machine interaction. The naturalness and variety of hand gestures offer a more direct and intuitive form of interaction that can be exploited in a large spectrum of applications. Moreover, 3D visualization on mobile devices is a task required by increasing number of scenarios ranging from video games to engineering. In this paper, the impact of MTUIs when applied to 3D scene navigation on handheld devices is investigated. Numerical measures as well as subjective results (based on user feedback) are exploited in order to analyze the effectiveness of MTUIs compared with a traditional buttonbased user interface. The two GUIs are compared in terms of time and number of interactions to complete three reference tests. In particular, a statistical analysis based on paired t-tests shows how the proposed MTUI can, in general, outperform a traditional button GUI; differences between GUIs are strongly reduced when a fine control of objects is required.