Hefei Dialect High Vowel Experimental Study

Hefei dialect is a representative dialect in Hongchao dialectal area of Jianghuai dialect. It has eleven simple vowels : i,(?) (y),(?),(?),u,(?),(?),a,e,I,(?). This paper use experiment to research timbre of high vowels and acoustical represents about friction of high vowels in Hefei dialect. In addition we try to analyse phonetic changes and the reasons of the changes in Hefei dialect with acoustic and phonology.This experiment uses Praat4.3.27 obtain F1 and F2 of the eleven simple vowels. By analyzing stdevp and disperse degree of Fl and F2, We compared the formant mode of the eleven simple vowels with Putonghua and make conclusions: the timber of (?),(?),(?),I,u,(?) are precarious; There is clear friction when pronounce (?),(?),u; the most simple vowels exit in upside of acoustic space.This paper is focus on acoustic features of high vowels in Hefei dialect and we draw some important conclusions : (1) The friction is relates to articulation not phonation (2) The fills in high frequency area and the irregular undulation are features of high vowels. (3) The energy of fills and intensity of irregular undulation is the features of friction extent, so it is the times of friction segment .If the fills energy is big or the intensity of irregular undulation is obvious or the times is longer, then the friction will be stronger. (4) The intensity of high vowels friction is also related to pronounce habits and pronounce state of the people in some extent. (5) The friction intensity is different evidently if (?),(?) combine with different initials: The friction is strongest if (?) combine with z,p' and the second with m,ts,p, the friction is weakest when the initials are ts',s. The friction is stronger of (?) combine with z than with ts,ts',s.We also discussed the speech changes and the reasons of high vowels in Hefei dialect. The results indicate that there is a course of composite vowels changed to simple vowels. The course caused the low vowels changed to high vowels. Some high vowels produced friction and changed into apical vowels finally. The speech changes course of simple vowels in Hefei dialect is caused by the composite vowels changed to simple vowels. Firstly, the composite vowels changed to simple vowels, then the simple vowels changed to high vowels, then i,u,y produced friction, finally i,y become apical vowels. We consider that the change yâ†'(?) is caused by iâ†'(?). Push chain, drag chain and analogy is in the main rule of phonetic change process.