Factors Affecting Nonnative Consonant Cluster Learning

Purpose: Nonnative consonant cluster learning has become a useful experimental approach for learning about speech motor learning, and we sought to enhance our understanding of this area and to establish best practices for this type of research. Method: One hundred twenty individuals completed a nonnative consonant cluster learning task within a speech motor learning paradigm. Following a brief prepractice, participants then practiced the production of eight word-initial nonna-tive consonant clusters embedded in bisyllabic nonwords (e.g., GD in /gdivu/). The clusters ranged in difficulty according to linguistic typology and sonority sequencing. Acquisition was operationalized as the change across the practice section and learning was assessed with two retention sessions (R1: 30 min after practice; R2: 2 days after practice). We evaluated changes in accuracy as well as in the acoustic details of the cluster production at each time point. Results: Overall, participants improved in their production of the consonant clusters. Accuracy increased, and duration measures decreased in specific measures associated with cluster production. The change in coordination measured in the acoustics changed both for clusters that were incorrectly produced and for those that were correctly produced, indicating continued motor learning even in accurate tokens. Conclusions: These results aid our understanding of the complexity of nonna-tive consonant cluster learning. In particular, both factors related to both phonological and speech motor control properties affect the learning of novel speech sequences. Supplemental Material: https://doi.org/10.23641/asha.21844185.