This narrative review synthesizes 24 empirical studies on the role of four types of pedagogical gestures (beat, durational, pitch, and articulatory) in second language (L2) phonetic training since 2010. We reviewed studies involving training interventions to assess the efficacy, mediating factors, and robustness of multimodal training. The findings confirm that gestural training is a powerful tool, yielding the most robust positive effects for L2 speech production and the acquisition of suprasegmental features. Crucially, the effectiveness is highly dependent on gesture-sound consistency and visual saliency of the target phonetic/prosodic feature. However, results are mixed regarding perceptual learning and the generalization of gains to untrained items or novel contexts. While the literature supports the value of gestural training, there are gaps in determining the optimal training paradigm (observing gestures vs. performing gestures), accounting for individual learner differences, and establishing long-term retention and ecological validity. Future research should incorporate longitudinal designs and neurophysiological methods to fully illuminate the cognitive mechanisms that drive the body–mind link in L2 speech acquisition.
Xi et al. (Wed,) studied this question.