A Case Study Of The Characteristics Of English Diphthongs By Chinese University Students

The paper investigates the acoustic features of English diphthongs produced by Chinese non-English major university students (hereinafter referred to as PTHS) through the combination of Perception experiments and Acoustic experiments. The paper aims at finding out the characteristics and difficulties the Chinese students have in producing English diphthongs.Diphthongs are compound vowels which are formed by two target vowels. When producing them, the speaker needs to slide from the first target vowel gradually to the second target vowel. Diphthongs change in quality and the entire sliding process involves three stages:beginnging stage, transitional stage and ending stage. The similarities and differences between English and Chinese phonetic system will influence the diphthongs produced by PTHS to some extend. This paper mainly focuses on the acoustic parameters of formants, duration and duration radio of three stages within the diphthongs. By using the acoustic analysis software PRAAT, Fland F2 formant values of the beginning stage and ending stage in non-continuous and continuous speech flow are measured and the acoustic vowel charts are also drawn according to the data. The duration of their pronunciation and the radio of each stage are also measured. Comparing with the acoustic parameters of English diphthongs produced by RP English speakers (hereinafter referred to as RPS), the paper tries to find out the similarities and differences between the pronunciation of the two groups and analyzes the causes as well.The results are as followed:as far as the formants are concerned, the pronunciation of English diphthongs by PTHS is influenced by their counterparts in Chinese. The way that PTHS produce [ei] and [ai] respectively is closer to Chinese diphthong ei and ai;ao and ou in Chinese don't influence PTHS too much when they produce [au] and [(?)u]. For those English diphthongs which have no counterparts in Chinese, PTHS share similar formants values with RPS. But overall, PTHS don't undergo as obvious tongue changing as RPS do. As far as the duration and the duration radio are concerned, the total length of English diphthongs generated by PTHS is influenced by the similar diphthongs in Chinese and is shorter than those generated by RPS; while for those diphthongs without similar ones in Chinese, the length is relatively close to those produced RPS. The duration radio of each is influenced neither by English nor Chinese diphthongs. The duration pattern of each English diphthong produced by PTHS shows a unique characteristic. In view of the above results, the author recommends that teachers should constantly improve their pronunciation accuracy and help students in their acquisition of English diphthongs with the help of acoustic software and equipments.