An Experimental Phonetic Study Of Tone Sandhi Of Disyllabic Words In Tanchang Dialect

Tone is one of the key features of Chinese speech,which has been the research hotspot of many phonetic scholars.Tone sandhi refers to a dynamic combination of two or more syllables in Chinese in which the tone of some syllables changes due to the influence of the preceding and following syllables when they are consecutive.Tanchang county is located in the south of Gansu Province and the northwest of Longnan City.Tanchang dialect belongs to Qinlong district of Central Plains Mandarin.As for the research on the phonology of Tanchang dialect,previous studies have made some achievements by using traditional dialectology methods,but at present,it only involves the citation tones and tone values of citation tones,and there is no in-depth investigation and research on the tone sandhi phenomenon of Tanchang dialect.In view of this,this thesis takes the tones of Tanchang dialect as the research object,and uses the method of experimental phonetics to analyze tone values of disyllabic sequences and tone sandhi in disyllabic sequences of Tanchang dialect,in order to more comprehensively and accurately reflect and reveal the tone sandhi patterns of Tanchang dialect.This thesis obtains the experimental data of citation tones and disyllabic sequences tones in Tanchang dialect through phonetic experiment.On this basis,taking autosegmental phonology and optimality theory as the theoretical framework,this thesis describes the underlying forms of citation tones in Tanchang dialect,characterizes the tonal patterns of disyllabic tone sandhi,and makes phonological analysis of the phenomenon of tone sandhi of Tanchang dialect by revealing the phonological ranking constraints of tone sandhi of disyllabic sequences in Tanchang dialect.The experimental phonetic analysis method is adopted to analyze the collected materials of Tanchang dialect.Praat 6.2.09 software is used to analyze the sound recording materials（monosyllabic words,non-reduplicated disyllabic words and reduplicated disyllabic words except for the neutral tones）.The thesis shows that there are four citation tones in Tanchang dialect: yinping（44）,yangping（23 or 34）,shangsheng（53）and qusheng（33）.There are mainly five distinct tone sandhi patterns in disyllabic sequences.The patterns of tone sandhi are summarized as follows:T2→T4/T1 HH+LH→HH+LLT2→T4/ T2 LH+LH→LL+LLT2→T4/T2 LH+LH→LL+LLT2→T4/ T3 LH+HL→LL+HLT3→T4/ T3 HL+HL→LL+HLT1→T4/T4 LL+HH→LL+LLOn the basis of experimental phonetic analysis,the thesis uses optimality theory to analyze the tone sandhi phenomenon of disyllabic sequences in Tanchang dialect.The ranking hierarchy of relative constraints is DEP-IO（T）,Level-Stab >> *RTA >> IDENT-IO >> OCP.The thesis not only uses the optimality theory and related constraints to scientifically and reasonably explain the reasons of tone sandhi patterns in Tanchang dialect,but also will have reference significance for the further phonological research of Tanchang dialect.