Intensive Foreign Language Learning Reveals Effects on Categorical Perception of Sibilant Voicing After Only 3 Weeks.

Models of speech learning suggest that adaptations to foreign language sound categories take place within 6 to 12 months of exposure to a foreign language. Results from laboratory language training show effects of very targeted training on nonnative speech contrasts within only 1 to 4 weeks of training. Results from immersion studies are inconclusive, but some suggest continued effects on nonnative speech perception after 6 to 8 years of experience.