Numerous findings suggest that non-native speech perception undergoes dramatic changes before the infant' s first birthday. Yet the nature and cause of these changes remain uncertain. We evaluated the predictions of several theoretical accounts of developmental change in infants' perception of non-native consonant contrasts. Experiment 1 assessed…

Behavioral studies have shown that while young infants can discriminate many different phonetic contrasts, a shift from a language-general to a language-specific pattern of discrimination is found during the second semester of life, beginning earlier for vowels than for consonants. This age-related decline in sensitivity to perceive non-native…