Radio debuted as a wireless alternative to telegraphy in the late 19th century. At its inception, wireless technology could only transmit signals and was incapable of broadcasting actual voices. During the 1920s, however, it transformed into a medium primarily identified as one used for entertainment and informational broadcasting. The commercialization of American broadcasting, which included the establishment of national networks and reliance on advertising to generate revenue, became the so-called American system of broadcasting. This transformation demonstrates how technology is shaped by the dynamic forces of the society in which it is embedded. Broadcasting’s aural attributes also engaged listeners in a way that distinguished it from other forms of mass media. Cognitive processes triggered by the disembodied voices and sounds emanating from radio’s loudspeakers illustrate how listeners, grounded in particular social, cultural, economic, and political contexts, made sense of and understood the content with which they were engaged. Through the 1940s, difficulties in expanding the international radio presence of the United States further highlight the significance of surrounding contexts in shaping the technology and in promoting (or discouraging) listener engagement with programing content.