中古音
In terms of historical Chinese phonology, modern "beimihu" () is simpler than its presumed 3rd-century late Old Chinese or early Middle Chinese pronunciation. Compare the following reconstructions of the name in "Archaic" or "Middle Chinese" (Bernhard Karlgren, Li Fanggui, and William H. Baxter), "Early Middle Chinese" (Edwin G. Pulleyblank), and, historically closest, "Late Han Chinese" (Axel Schuessler).