Although previous research indicates that Japanese speakers’ second-language (L2) perception and production of English /ɹ/ may improve with increased L2 experience, relatively little is known about the fine phonetic details of their /ɹ/ productions, especially during the early phase of L2 speech learning. This cross-sectional study examined acoustic properties of word-initial /ɹ/ from 60 Japanese learners with a length of residence (LOR) between one month and one year in Canada. Their performance was compared to that of 15 native speakers of English and 15 low-proficiency Japanese learners of English. Formant frequencies (F2 and F3) and F1 transition durations were evaluated under three task conditions—word reading, sentence reading, and timed picture description. Learners with as little as two to three months of residence demonstrated target-like F2 frequencies. In addition, increased LOR was predictive of more target-like transition durations. Although the learners showed some improvement in F3 as a function of LOR, they did so mainly at a controlled level of speech production. The findings suggest that during the early phase of L2 segmental development, production accuracy is task-dependent and is influenced by the availability of L1 phonetic cues for redeployment in L2
