THE INFLUENCES OF ORTHOGRAPHIC FORMS, STRESS PLACEMENT AND CONSONANTAL MANNERS ON SYLLABIFICATION AND ACOUSTIC DURATIONS OF INTERVOCALIC CONSONANTS WITH GEMINATE GRAPHEMES BY THAI L2 SPEAKERS OF ENGLISH

Abstract

This dissertation investigates the interplay of orthographic forms, stress, and consonantal manners in syllabification and acoustic durations of intervocalic consonants with singleton and geminate graphemes by Thai L2 speakers of English, classified into three CEFR proficiency levels: A1, A2 and B1. This study encompasses two experiments: syllabification and production. The syllabification experiment employed the word-part identification task, comprised of 64 multiple-choice questions, in which the participants were instructed to identify the first part of a word in one question and the second part of the same word in another. The findings revealed dynamic changes in syllabification preferences as L2 proficiency increased. The initial stages of acquisition displayed a strong reliance on orthographic forms for syllabification. An increase in proficiency is associated with a growing awareness of the interaction of stress placement with syllabification and declining orthographic reliance. The production experiment utilized the reading aloud task, wherein participants were asked to read aloud 32 target words in a carrier sentence. The acoustic durations of intervocalic consonants were analyzed using Praat software (Boersma & Weenink, 2021) based on waveforms and spectrograms. The results indicated that all groups of participants produced intervocalic consonants orthographically represented as geminates significantly longer than those orthographically represented as singletons. The durational ratio of orthographic singletons to geminates is on average greater for intervocalic consonants in pre-stress positions than for those in post-stress positions. Across all Thai participant groups, the ratio is greater for intervocalic sonorants than for obstruents in post-stress positions, whereas in pre-stress positions, the ratio is greater for obstruents. This ratio steadily decreases from A1, A2 and B1 to NES participant groups. The findings underscore the consistency observed in both experiments as higher English proficiency correlates with native-like syllabification and acoustic duration.

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