This article explores how the concept that we have chosen to call unvoicing practices, namely veiled discursive micro processes of social exclusion and silencing that social actors manage in byplay; in other words, subordinated forms of communication among a subset of unaddressed members of ratified listeners. These practices constitute efficient resources aimed at the (de)legitimization of linguistic mude processes within new “spaces of multilingualism” associated with migration in Galicia. The research was carried out in the second-year class of a Curricular Diversification Programme at a secondary school in Arteixo (A Coruña, Galicia, Spain), a community that has experienced an increase in its allochthonous population in recent years. The corpus of this study comprises the pupils’ linguistic biography, classroom interactions and a fieldwork log. The analysis shows the complex network of scales in which languages are legitimized or delegitimized – specifically, translinguistic practices of listeners’ participation in which local varieties of Spanish and Galician, youth slang and parodic double of Moroccan Arabic are crossed and make themselves heard through byplay in order to silence the principal speaker. This interactional distribution results in the latent discursive reconstruction of new translocal spaces in which migration-associated multilingualism remains peripheral and practically invisible.