益沅小片湘语古全浊声母的弱化现象

The Weakening of the Middle Chinese Voiced Initials in Yiyuan Sub-cluster of Xiang Dialect

古全浊声母舒声字的弱化是益沅小片湘语中十分突出的语音演变现象。在音值上,古全浊声母弱化后今读浊擦音、近音、鼻音、边音、零声母等;在地理分布上,弱化程度由西北向东南渐次递减;在弱化顺序上,浊擦音最容易弱化,浊塞擦音次之,浊塞音最难弱化;在弱化的语音条件上,调类以及韵母的读音对弱化起着重要的制约作用。

Weakening is a common phenomenon in evolution of the Middle Chinese（MC） voiced initials in Yiyuan sub-cluster of Xiang dialect. The MC voiced initials of shusheng （舒声）characters were shifted to fricatives, nasals, laterals and zero initials and so on. Geographically speaking, the weakening level is gradually decreased from the northwest to the southeast; the voiced fricatives weaken more often than the voiced affricatives, with stops as the most stubborn ones against the weakening. Tone types and the finals also pose constrains on the weakening.