A pilot acoustic study of Modern Persian vowels in colloquial speech

Abstract

While the current literature on Modern Persian (MP) shows heightened interest in its vowel inventory, a cogent synchronic account of Modern Persian vowels (MPV) has yet to be presented. Previous phonological descriptions of MPV presuppose a pairing system based on a historical length distinction that is still reflected in MP orthography: /i:, e/, /u:, o/, /ɒ:, æ/. A synchronic phonological analysis of MPV must be based on phonetic measurements; however, existing acoustic studies examine only formal speech, and thus do not reflect colloquial surface forms. Therefore, the goal of this investigation is to lay the groundwork for a comprehensive acoustic study of MPV that presupposes no pairings and is based on colloquial speech in a controlled prosodic environment. Vowel duration and first and second formants were measured using Praat for 90 CVC(C) monosyllables as pronounced phrase-finally in carrier sentences by two Tehrani native speakers: one male, one female. Results show that average durations for each vowel contradicted the traditional length-based pairings. Furthermore, features of the following phonological environment likely to affect vowel length — postvocalic consonant type, coda complexity (CVC vs. CVCC), and adherence to the Sonority Sequencing Principle in complex codas — had no notable effect. Results of formant measurements show the two non-high back vowels to be higher than expected, whereas the high back vowel was noticeably centralized.