The first five questions (Q1–Q5) addressed students’ mental models of sound at the microscopic level more directly in different scenarios: production; transmission in air, in solids and through a solid wall; and perception in the ear. The central role of mental models in science education as well as the difficulties in modelling physical concepts have been widely investigated (e.g. Coll and Treagust 2003; Coll 2005; Teodoro 2006; Gokdere and C¸ alik 2010). To delimit the specific mental models proposed, we used the conclusions of Hrepic (2004), Hrepic et al. (2010) and Linder and Erickson (1989) (basic models and model hybridisations).