this paper addresses the validity of two hypotheses concerning changes of vowel quality in persian. the theory of centralization claims that there is a strong correlation between vowel duration and vowel quality. as vowel duration is shortened in unstressed contexts, the size of the vowel inventory reduces toward the center, leading to considerable overlap between different categories and a red...

this study examines the phonetic properties of lexical stress in english produced by persian speakers learning english as a foreign language. the four most reliable phonetic correlates of english lexical stress, namely fundamental frequency, duration, intensity, and vowel quality were measured across persian speakers’ production of the stressed and unstressed syllables of five english disyllabi...

This paper reports the results of an experimental study on non-native production of English vowels. Two groups of Persian EFL learners varying in language proficiency were tested on their ability to produce the nine plain vowels of American English. Vowel production accuracy was assessed by means of acoustic measurements. Ladefoged and Maddison’s (1996) F1 F2 measurements for American English v...

Cross-linguistically, vowel length contrasts may involve changes in vowel quality. In a different but more gradient way, speech style influences vowel articulation. While both alter vowel acoustics, it remains unclear whether both are byproducts of general processes of vowel undershoot or reflect a modification of articulatory gestures independent of durational constraints. This study investiga...

Several experiments have found that changing the intrinsic f0 of a vowel can have an effect on perceived vowel quality. It has been suggested that these shifts may occur because f0 is involved in the specification of vowel quality in the same way as the formant frequencies. Another possibility is that f0 affects vowel quality indirectly, by changing a listener's assumptions about characteristic...

This study aims to quantify the relative contributions of phonetic categories and acoustic detail on phonotactically induced perceptual vowel epenthesis in Japanese listeners. A vowel identification task tested whether a vowel was perceived within illegal consonant clusters and, if so, which vowel was heard. Cross-spliced stimuli were used in which vowel coarticulation present in the cluster di...

Although vowel quality is an important cue to the perception of English lexical stress, few studies have examined the role this cue plays for non-native speakers. Previous research found that Mandarin speakers had problems using vowel reduction as a cue in English lexical stress production. Assuming native-like perception is a prerequisite to native-like production for non-native speech, this s...