How explicit instruction improves phonological awareness and perception of L2 sound contrasts in younger and older adults

Despite the importance of conscious awareness in second language acquisition theories, little is known about how L2 speech perception can be improved by explicit phonetic instruction. This study examined the relationship between phonological awareness and perception in Dutch younger and older adult L2 listeners, focusing on English contrasts of two types: a familiar contrast in an unfamiliar position (word-final /t/-/d/) and an unfamiliar contrast (/æ/-/ε/). Awareness was assessed with a task in which written minimal pairs and homophone pairs had to be judged as sounding the same or different. Perception was assessed with a two-alternative forced-choice identification task with auditorily presented words from minimal pairs. We investigated whether listeners’ awareness and perception improved after a video-based explicit instruction that oriented their attention to one of these contrasts, and we tested whether including information about the phonetic cue of vowel duration increased learning. Awareness and perception of each contrast were shown to be moderately correlated at the study’s outset. Furthermore, awareness and perception for each contrast generally improved more after the instruction drawing attention to that contrast. However, the effectiveness of explicit phonetic instruction varied depending on the combination of the contrast, cue information, and listener age group.