This contribution focuses on a very specific episode in the history of lan-guage teaching methodologies: the influence of Théodore Rosset and his teaching of pronunciation for foreigners based upon experimental phonetics and an innovative dispositive, and two important elements in how knowledge flowed across the Atlantic. First or all, the presence in Grenoble in 1909 of a very special student, Frank C. Chalfant, who imported to the United States Rosset’s teaching methods. Secondly, the fact that soldiers and officers have been trained in Grenoble in the early years of the 20th century. This study sheds a new light on the context that preceded the emergence of the American Speech Training Program (ASTP) in the United States.