On the Difficulty of Defining “Difficult” in Second-Language Vowel Acquisition

Hierarchies of difficulty in second-language (L2) phonology have long played a role the postulation and evaluation learning models. In L2 pronunciation teaching, hierarchies are assumed to be helpful development instructional strategies based on anticipated areas difficulty. This investigation addressed practicality defining pedagogically useful hierarchy for English tense lax close vowels (/i I u ʊ/) produced by Cantonese speakers. Unlike their counterparts, tense-lax pairs allophonic variants with [i u] occurring before alveolars [I ʊ] velars. Each pair represents “phonemic split” which members single L1 category realized contrastively L2. Despite evidence that distinctions challenging speakers, no previous empirical work has closely considered problem from standpoint vowel intelligibility across multiple phonetic contexts different words sharing same rhyme. picture-based word-elicitation task, 18 Cantonese-speaking participants 31 high-frequency CV CVC words. Vowels were evaluated phonetically-trained judges. A series mixed-effects binary logistic models fitted scores, quality, context (rhyme) word as factors, length Canadian residence daily use co-variates. As expected, general emerged (/i/ > /u/ /ʊ/ /I/) was complicated large differences contexts. Results not readily explicable terms transfer; moreover, rhyme equal intelligibility. The most serious modeling complication sizeable inter-speaker variability difficulties, could accounted model Although some difficulties roughly systematic at group level, it is argued establishing such data would prove intractable. Rather, learners might better served assessment targeting individual than focus errors predicted