Tangible user interfaces empower artists, boost their creative expression and enhance performing art. However, most of them are designed to work with a set of rules, many of which require advanced skills and target users above a certain age. Here we present a comparative and quantitative study of using TUIs as an alternative teaching tool in experimenting with and creating soundscapes with children. We describe an informal interactive workshop involving schoolchildren. We focus on the development of playful uses of technology to help children empirically understand audio feature extraction basic techniques. We promote tangible interaction as an alternative learning method in the creation of synthetic soundscape based on sounds recorded in a natural outdoor environment as main sources of sound. We investigate how schoolchildren perceive natural sources of sound and explore practices that reuse prerecorded material through a tangible interactive controller. We discuss the potential benefits of using TUIs as an alternative empirical method for tangible learning and interaction design, and its impact on encouraging and motivating creativity in children. We summarize our findings and review children's biehavioural indicators of engagement and enjoyment in order to provide insight to the design of TUIs based on user experience.