With the introduction of the technique of auscultation in nineteenth-century medicine, the auditory became a most important means of producing diagnostic knowledge. The correct classification and interpretation of the sounds revealed by auscultation, however, remained an issue of negotiation and often controversy throughout the mid-nineteenth century. This article examines the codification of lung sounds within two cultural and geographic contexts: first, the original approach as it was developed by Laennec and his followers in Paris that came to be dominant in (...) French medicine, and second, the alternative approach that grew out of Joseph Skoda’s reception of Laennec’s method in Vienna and became widely adopted in the German-speaking world. On one hand, it will be argued that lung sound classifications attempted a standardization of the perception and the interpretation of auscultation sounds. On the other hand, it will be shown that the development of auscultation sounds was shaped by the local context in which it took place. This article seeks to shed light on the way in which auditory experiences were instrumentalized for epistemic purposes in medicine. Furthermore, it discusses the role of standardization both as a mechanism for the universalization of knowledge and as a contextually bounded practice. (shrink)