Chapter 4 Perception and Synthesis of Sound-Generating Materials Bruno L. Giordano and Federico Avanzini 4.1 Introduction The mechanical properties of sound-generating objects and events in our environment determine lawfully the acoustical structure of the signals they radiate (e.g. Fletcher and Rossing 1991). The ability of listeners to estimate the mechanical properties of everyday non-vocal, non-music sound sources based on acoustical information alone has been the object of empirical research for more than three decades (Vanderveer 1979). Given the lawful specification of the mechanics of the sound source in the acoustical structure, and the adaptive tendency to interpret sensory information in terms of the properties of objects and events in the environment, it is thus not surpris- ing that source-perception abilities are often remarkably accurate (see Lutfi 2007, for a review). The concept of material is central to the study of source perception from both a theoretical and empirical point of view. The theoretical relevance of this concept originates from the work of Gaver, who outlined a widely influential taxonomy of everyday sound events (Gaver 1993). Accordingly, non-vocal sound sources offer perceptual systems with information about “materials in interaction”, and, at the most general level of the taxonomy, can be classified into three categories depending on the state of matter of the vibrating sound-generating substance: (i) solid sound sources (e.g. clapping); (ii) liquid sound sources (e.g. pouring coffee); (iii) aero- dynamic/gaseous sound sources (e.g. wind; explosions). For a variety of reasons (e.g. easiness in manipulation of source mechanics; ecological pervasiveness), the B.L. Giordano (B ) Institute of Neuroscience and Psychology, University of Glasgow, 58 Hillhead Street, Glasgow G12 8QB, UK e-mail: brungio@gmail.com F. Avanzini Department of Information Engineering, University of Padova, Via Gradenigo 6/A, 35131 Padova, Italy e-mail: avanzini@dei.unipd.it © Springer-Verlag London 2014 M. Di Luca (ed.), Multisensory Softness, Springer Series on Touch and Haptic Systems, DOI: 10.1007/978-1-4471-6533-0_4 49