How do we recognise children's participation and their relationships to public life? Drawing on evidence from ethnographic fieldwork conducted between 2014-2016 for the ERC funded Connectors Study on the relationship between childhood and public life, this paper explores the ways in which children communicate their encounters with public life. Τhe contemporary phenomenon of listening without hearing is discussed as this relates to the call for listening to children and the simultaneous failure to hear what they say. Idioms are introduced as an 'instrument' for thinking through what it means and feels like to encounter and make sense of childhood and children's practices of relating to public life. The analysis focuses on three emblematic encounters with six-to eight-year-old children living in Athens, Hyderabad, London. We argue that dominant understandings of listening to children rely heavily on cognitive, conceptual and rational models of idealised and largely verbal forms of communication that ignore the affective, embodied and lived dimensions of making meaning. Through ethnographic thick description we trouble what it means to tune into children's worlds and to 'properly hear', and in so doing demonstrate the ways in which idioms support an understanding of what matters to children. Drawing on evidence from ethnographic fieldwork conducted between 2014-2016 for the ERC funded Connectors Study on childhood and public life, this paper develops the concept of idioms as an 'tuning device' for understanding children's cultures and their communication therein, as meaningful and agentic. The term idiom, as used in anthropological and other social science literatures, provides an understanding of the act of communication that goes beyond linguistics and spoken language. It shifts attention towards communication as a social, cultural, temporal, as well as fully sensory act, that includes gestures, practices, actions, and affect. As such, idioms are a way of world-making and this paper focuses specifically on those idioms that were mobilised by children to make sense of and communicate their encounters with and experiences of public life. Children in the study understood public life as activities, places, and things that were accessible, communal, civil and political, known and open (e.g. a range of institutions, parks, toilets, voting, etc). A number of children also commented on the difficulty, also found in the literature, of providing a definition of public life (e.g. 'I don't know how to describe what I know aboutit'). In the social science literature and in practice, such encounters and experiences are often referred to as children's participation and much has been made in theory and in practice of 'listening to children' as a medium for participation. While the failure to listen is systemic and often political, we argue that useful sensitising devices (concepts used to think and act with), such as we have found idioms to be, can support theory and practice development that better resonates with everyday childh...