In terms of the theory and method of language variation of sociolinguistics, this paper discusses the relationship between speech adaptation and phonetic variation based on an investigation phonetic variation within the Island of Science in Hefei. The study discovers that the interrelated data between distribution of phonetic variation and social factors in the community show the variants /i/, /y/ and / ending / indicate phonetic changes in progress, that “the sense of language insecurity” is the social drive of phonetic changes in progress, and that “the longterm language adaptation” has effects on the dialect system in manner of “leveling the dialect”, which also works as a leading factor for phonetic changes in progress.

sociolinguistics; theory of language variation; speech adaptation; leveling the dialect