Perceptual sensitivity to vowel quality and vowel length in the first year of life

The perceptual attunement to native vowel categories has been reported to occur at 6 months of age. However, some languages contrast vowels both in quality and in length, and whether and how the acquisition of spectral and duration-cued contrasts differs is uncertain. This study traced the development of infants' sensitivity to native (Czech) vowel-length and vowel-quality contrasts. The results suggest that in a vowel-length language, infants learn to categorize vowels in terms of length earlier and/or more robustly than in terms of quality, the representation of which may still be relatively underdeveloped at 10 months of age.