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...

introduction: the feedback provided by auditory apparatus equips normal hearing people with an important controlling mechanism over the speech production processes. the speech of hearing-impaired children is both perceptually and acoustically abnormal. this study tried to compare the formant frequencies of three long vowels in persian-speaking children who used cochlear implant and those who we...

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...

This paper reports on the articulatory and acoustic correlates of the mid-central vowel (schwa) in an attempt to find out the perimeter of this vowel in both the articulatory and acoustic vowel space of female American English speakers. F1xF2 plots were used to determine the acoustic vowel space. The articulatory vowel space was determined by plotting the maximum vertical displacement of the ja...