The relationship between electro-acoustic technologies and political power around 1930 has been a matter of much debate in contemporary scholarship. A large part of existing research defines radio and talkies as repressive instruments, imposed by the Nazi and Soviet dictatorship with the purpose of assembling far- reaching surveillance structures. Conversely other researchers increasingly see repressive regimes as rooted in scientific inventions in the field of telecommunications. In this second research corpus, the radio, the loudspeaker and sound film are assigned a structuralizing function with regard to the reproduction of political power. The solution to this apparent contradiction might be that different approaches, based on social history, linguistics, semiotics and theory of perception, have been used to deal with the question of the interplay between technological media and the development of community. The study will analyze how electro-acoustic knowledge, with its ethical implications, was implemented in early radio and film projects. The following questions will be addressed in connection with this main research focus: What psycho-acoustic and ethno-cultural aspects of sound performance were rated most important in the context of transforming environmental sounds and natural human voices into an electro-acoustic design? How were differences between low vs. high pitch sounds, between male vs. female voices played up in newsreels, e.g. with regard to the semantic differentiation of events, presented either as hard or as soft news? The analysis of early sound sources and public debates carried out by radio & film magazines in Germany (Funk), Soviet Union (Radio front) and Great Britain (Radio times) should provide an answer to the questions posed. The purpose of this analysis is to determine the contribution of electro-acoustic technologies to the emergence of a mass media public sphere and the continuity of local acoustic communities.