The study of vowel reduction in Persian spontaneous speech

Vowel reduction that occurs in spontaneous speech is a process in which unstable vowels undergo qualitative changes in unstressed syllables. This process may be either due to the effect of the addition of one or more affixes to the stem that attracts the stress, or the result of the tendencies of vowels towards each other without being affected by affixation. We call the first process, phonemic vowel reduction and the second one, phonetic vowel reduction. Sonority-driven approach of Crosswhite (2000) and, centripetal and centrifugal approaches of Harris (2005) serve as the theoretical frameworks for our analysis of vowel reduction in the colloquial Persian. Acoustic analysis of our data lead us to conclude that Persian vowel reduction obeys a hybrid approach because the unstable vowels /a,e,o/ change not only into one another but also into the stable vowels /ɑ, u, i /.