When studying for a doctoral degree (PhD), candidates submit a thesis that provides a critical review of the current state of knowledge of the thesis subject as well as the student’s own contributions to the subject. The distinguishing criterion of doctoral graduate research is a significant and original contribution to knowledge.
Once accepted, the candidate presents the thesis orally. This oral exam is open to the public.
Despite considerable progress in research on the impact of age of acquisition (AOA) and language exposure on general second language (L2) learning, pronunciation has received limited attention in the school setting and findings remain inconclusive: while some studies conclude that earlier starters outperformed late starters (e.g., Fullana & Mora, 2007), others find that neither AOA nor exposure have a significant effect on participants’ pronunciation (e.g., MacKay & Fullana, 2007). A possible explanation for these inconclusive results could be that researchers adopt different measures (tasks) to assess pronunciation, without considering the effects they can have on learners’ performance (Saito & Plonsky, 2019).
To address the effects of AOA, language exposure, and task type on the acquisition of L2 pronunciation, this thesis examined the oral production of 68 Tunisian learners of French (age 8-12) considering two AOAs (4 and 8 years), two levels of L2 exposure (1000h and 1600h), using four task types: word list reading, sentence reading, picture identification, and storytelling. The analysis focused on the participants’ global (accentedness, comprehensibility, and intelligibility) and specific (four vowels and consonants, and stress) pronunciation knowledge. For each task, global pronunciation was assessed by three non-native listeners (using ratings and transcriptions, Derwing & Munro, 1997), while specific pronunciation was measured using perceptual auditory and acoustic analysis. Results indicate that there was no significant difference between older and younger learners. Also, results demonstrated that the group with more exposure (1600h) produced more target-like forms than the group with less exposure (1000h). Significant task effects were observed, with participants producing more target-like forms in more controlled tasks. These findings suggest that exposure to the target language plays a more important role in determining learners’ pronunciation abilities in comparison with AOA, and that task type must be taken into consideration in studies examining L2 phonological development.