Terhardt, E. (1992). From speech to language: On auditory information processing. In: (Schouten, M. E. H., ed.), The Auditory Processing of Speech: From Sounds to Words. Mouton de Gruyter, Berlin, 363-380
This paper outlines the hierarchical processing of complex sounds in general, and that of speech in particular. The main conclusion is that "central processing", i.e., knowledge-based contourization and formation of Gestalt features, is not just central. Rather, it is distributed on all levels of the auditory system, and significant processes of abstraction are carried out on low levels of the auditory hierarchy.