Acquisition of non-sibilant anterior English fricatives by adult second language learners

This study examined the acquisition of the non-sibilant anterior fricatives /v, θ, ð/ by adult second language (L2) English talkers. Twenty-four Mandarin Chinese-L2 English talkers read aloud fricative-initial words. These talkers were chosen as their L1 contained /f/ but not /v, θ, ð/. Twenty L1 English listeners were asked to identify the L2-produced speech and rate the talker’s accent. On average, 69% of the fricatives were correctly identified. /v/ was the most difficult to correctly identify and was identified less accurately than /θ/ and /ð/. A ‘moderate’ accent was reported by L1 listeners, but accent rating did not predict L1 identification behavior. An exploratory acoustic analysis involving the correctly identified words from 22 talkers revealed that L2 talkers produced mean temporal differences used for voicing in line with published L1 data. Non-sibilant fricatives – particularly /v/ – may require pedagogical interventions to push L2 talkers off their learning plateau.