The contributions featured in the theme issue “Sounds of Language—Languages of Sound” address the period between approximately 1890 and 1970—from the modern disciplinary formation of knowledge about sound and the rise of the social sciences and humanities to the beginnings of computerized sound research. During this period, disciplines as diverse as linguistics, musicology, history, sociology, law, and theology all aspired to give scholarly attention to sound, and in particular to the spoken word. Starting from the observation that late nineteenth-century scholars of language turned from expert readers of historical texts into expert listeners to living languages, the authors trace the dual use of language as an object and a tool of knowledge production. As a research theme, language often broke through frontiers between the humanities, the social sciences, and the natural sciences, as well as between academic and nonacademic domains of knowledge. At the same time, new languages and modes of speaking arose as tools to examine, represent, and utilize sonic phenomena—whether in speech, music, or other sonic environments. The theme issue’s three claims are, first, that sound both enabled and necessitated new alliances between otherwise divergent fields of knowledge; second, that sound and language motivated humanities scholars to reconsider or even reinvent their methodologies; and, third, that research on sound and language was deeply permeated by issues of power and politics.