Can perception training improve the production of second language phonemes? A meta-analytic review of 25 years of perception training research

Cognitive scientists across disciplines have shown a vested interest in examining if and how the speech perception and production modalities are connected. The field of second language (L2) acquisition contributes to this discussion by investigating the effects of auditory training of L2 sounds on pronunciation. This meta-analysis offers a comprehensive view of the last 25 years of L2 perception training studies that test for effects in production. The results indicate that the two modalities are connected, insomuch as training the perception of L2 sounds can induce positive change in the productive mode as well. The data indicate that strictly controlled perception training led to medium-sized improvements in perception ( d = 0.92, SD = 0.96) and small improvements in production ( d = 0.54, SD = 0.45). A correlation analysis suggests a small- to medium-sized relationship between perception and production gains, although this relationship was not significant. The production of obstruents improved to a larger degree than sonorants or vowels, and an additional six moderating variables influenced the magnitude of the production effect sizes. We caution researchers to not equate the connection of the two modalities in long-term linguistic development to real-time neurological processing, and we end with five recommendations for the domain of L2 phonetic training research.